Re: Linux 5.10.133

Greg Kroah-Hartman
2022-07-25T09:31:38Z

diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index ea8b704be705..1a58c580b236 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -4656,6 +4656,30 @@

retain_initrd [RAM] Keep initrd memory after extraction

+ retbleed= [X86] Control mitigation of RETBleed (Arbitrary
+ Speculative Code Execution with Return Instructions)
+ vulnerability.
+
+ off - no mitigation
+ auto - automatically select a migitation
+ auto,nosmt - automatically select a mitigation,
+ disabling SMT if necessary for
+ the full mitigation (only on Zen1
+ and older without STIBP).
+ ibpb - mitigate short speculation windows on
+ basic block boundaries too. Safe, highest
+ perf impact.
+ unret - force enable untrained return thunks,
+ only effective on AMD f15h-f17h
+ based systems.
+ unret,nosmt - like unret, will disable SMT when STIBP
+ is not available.
+
+ Selecting 'auto' will choose a mitigation method at run
+ time according to the CPU.
+
+ Not specifying this option is equivalent to retbleed=auto.
+
rfkill.default_state=
0 "airplane mode". All wifi, bluetooth, wimax, gps, fm,
etc. communication is blocked by default.
@@ -5005,6 +5029,7 @@
eibrs - enhanced IBRS
eibrs,retpoline - enhanced IBRS + Retpolines
eibrs,lfence - enhanced IBRS + LFENCE
+ ibrs - use IBRS to protect kernel

Not specifying this option is equivalent to
spectre_v2=auto.
diff --git a/Makefile b/Makefile
index 5bee8f281b06..fbd330e58c3b 100644
--- a/Makefile
+++ b/Makefile
@@ -1,7 +1,7 @@
# SPDX-License-Identifier: GPL-2.0
VERSION = 5
PATCHLEVEL = 10
-SUBLEVEL = 132
+SUBLEVEL = 133
EXTRAVERSION =
NAME = Dare mighty things

@@ -670,12 +670,21 @@ ifdef CONFIG_FUNCTION_TRACER
CC_FLAGS_FTRACE := -pg
endif

-RETPOLINE_CFLAGS_GCC := -mindirect-branch=thunk-extern -mindirect-branch-register
-RETPOLINE_VDSO_CFLAGS_GCC := -mindirect-branch=thunk-inline -mindirect-branch-register
-RETPOLINE_CFLAGS_CLANG := -mretpoline-external-thunk
-RETPOLINE_VDSO_CFLAGS_CLANG := -mretpoline
-RETPOLINE_CFLAGS := $(call cc-option,$(RETPOLINE_CFLAGS_GCC),$(call cc-option,$(RETPOLINE_CFLAGS_CLANG)))
-RETPOLINE_VDSO_CFLAGS := $(call cc-option,$(RETPOLINE_VDSO_CFLAGS_GCC),$(call cc-option,$(RETPOLINE_VDSO_CFLAGS_CLANG)))
+ifdef CONFIG_CC_IS_GCC
+RETPOLINE_CFLAGS := $(call cc-option,-mindirect-branch=thunk-extern -mindirect-branch-register)
+RETPOLINE_CFLAGS += $(call cc-option,-mindirect-branch-cs-prefix)
+RETPOLINE_VDSO_CFLAGS := $(call cc-option,-mindirect-branch=thunk-inline -mindirect-branch-register)
+endif
+ifdef CONFIG_CC_IS_CLANG
+RETPOLINE_CFLAGS := -mretpoline-external-thunk
+RETPOLINE_VDSO_CFLAGS := -mretpoline
+endif
+
+ifdef CONFIG_RETHUNK
+RETHUNK_CFLAGS := -mfunction-return=thunk-extern
+RETPOLINE_CFLAGS += $(RETHUNK_CFLAGS)
+endif
+
export RETPOLINE_CFLAGS
export RETPOLINE_VDSO_CFLAGS

diff --git a/arch/um/kernel/um_arch.c b/arch/um/kernel/um_arch.c
index 76b37297b7d4..26af24b5d900 100644
--- a/arch/um/kernel/um_arch.c
+++ b/arch/um/kernel/um_arch.c
@@ -358,6 +358,14 @@ void __init check_bugs(void)
os_check_bugs();
}

+void apply_retpolines(s32 *start, s32 *end)
+{
+}
+
+void apply_returns(s32 *start, s32 *end)
+{
+}
+
void apply_alternatives(struct alt_instr *start, struct alt_instr *end)
{
}
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index ed713840d469..16c045906b2a 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -453,15 +453,6 @@ config GOLDFISH
def_bool y
depends on X86_GOLDFISH

-config RETPOLINE
- bool "Avoid speculative indirect branches in kernel"
- default y
- help
- Compile kernel with the retpoline compiler options to guard against
- kernel-to-user data leaks by avoiding speculative indirect
- branches. Requires a compiler with -mindirect-branch=thunk-extern
- support for full protection. The kernel may run slower.
-
config X86_CPU_RESCTRL
bool "x86 CPU resource control support"
depends on X86 && (CPU_SUP_INTEL || CPU_SUP_AMD)
@@ -2415,6 +2406,88 @@ source "kernel/livepatch/Kconfig"

endmenu

+config CC_HAS_SLS
+ def_bool $(cc-option,-mharden-sls=all)
+
+config CC_HAS_RETURN_THUNK
+ def_bool $(cc-option,-mfunction-return=thunk-extern)
+
+menuconfig SPECULATION_MITIGATIONS
+ bool "Mitigations for speculative execution vulnerabilities"
+ default y
+ help
+ Say Y here to enable options which enable mitigations for
+ speculative execution hardware vulnerabilities.
+
+ If you say N, all mitigations will be disabled. You really
+ should know what you are doing to say so.
+
+if SPECULATION_MITIGATIONS
+
+config PAGE_TABLE_ISOLATION
+ bool "Remove the kernel mapping in user mode"
+ default y
+ depends on (X86_64 || X86_PAE)
+ help
+ This feature reduces the number of hardware side channels by
+ ensuring that the majority of kernel addresses are not mapped
+ into userspace.
+
+ See Documentation/x86/pti.rst for more details.
+
+config RETPOLINE
+ bool "Avoid speculative indirect branches in kernel"
+ default y
+ help
+ Compile kernel with the retpoline compiler options to guard against
+ kernel-to-user data leaks by avoiding speculative indirect
+ branches. Requires a compiler with -mindirect-branch=thunk-extern
+ support for full protection. The kernel may run slower.
+
+config RETHUNK
+ bool "Enable return-thunks"
+ depends on RETPOLINE && CC_HAS_RETURN_THUNK
+ default y
+ help
+ Compile the kernel with the return-thunks compiler option to guard
+ against kernel-to-user data leaks by avoiding return speculation.
+ Requires a compiler with -mfunction-return=thunk-extern
+ support for full protection. The kernel may run slower.
+
+config CPU_UNRET_ENTRY
+ bool "Enable UNRET on kernel entry"
+ depends on CPU_SUP_AMD && RETHUNK
+ default y
+ help
+ Compile the kernel with support for the retbleed=unret mitigation.
+
+config CPU_IBPB_ENTRY
+ bool "Enable IBPB on kernel entry"
+ depends on CPU_SUP_AMD
+ default y
+ help
+ Compile the kernel with support for the retbleed=ibpb mitigation.
+
+config CPU_IBRS_ENTRY
+ bool "Enable IBRS on kernel entry"
+ depends on CPU_SUP_INTEL
+ default y
+ help
+ Compile the kernel with support for the spectre_v2=ibrs mitigation.
+ This mitigates both spectre_v2 and retbleed at great cost to
+ performance.
+
+config SLS
+ bool "Mitigate Straight-Line-Speculation"
+ depends on CC_HAS_SLS && X86_64
+ default n
+ help
+ Compile the kernel with straight-line-speculation options to guard
+ against straight line speculation. The kernel image might be slightly
+ larger.
+
+endif
+
config ARCH_HAS_ADD_PAGES
def_bool y
depends on X86_64 && ARCH_ENABLE_MEMORY_HOTPLUG
diff --git a/arch/x86/Makefile b/arch/x86/Makefile
index 8ed757d06f77..1f796050c6dd 100644
--- a/arch/x86/Makefile
+++ b/arch/x86/Makefile
@@ -31,7 +31,7 @@ endif
CODE16GCC_CFLAGS := -m32 -Wa,$(srctree)/arch/x86/boot/code16gcc.h
M16_CFLAGS := $(call cc-option, -m16, $(CODE16GCC_CFLAGS))

-REALMODE_CFLAGS := $(M16_CFLAGS) -g -Os -DDISABLE_BRANCH_PROFILING \
+REALMODE_CFLAGS := $(M16_CFLAGS) -g -Os -DDISABLE_BRANCH_PROFILING -D__DISABLE_EXPORTS \
-Wall -Wstrict-prototypes -march=i386 -mregparm=3 \
-fno-strict-aliasing -fomit-frame-pointer -fno-pic \
-mno-mmx -mno-sse $(call cc-option,-fcf-protection=none)
@@ -196,7 +196,11 @@ ifdef CONFIG_RETPOLINE
endif
endif

-KBUILD_LDFLAGS := -m elf_$(UTS_MACHINE)
+ifdef CONFIG_SLS
+ KBUILD_CFLAGS += -mharden-sls=all
+endif
+
+KBUILD_LDFLAGS += -m elf_$(UTS_MACHINE)

ifdef CONFIG_X86_NEED_RELOCS
LDFLAGS_vmlinux := --emit-relocs --discard-none
diff --git a/arch/x86/boot/compressed/efi_thunk_64.S b/arch/x86/boot/compressed/efi_thunk_64.S
index c4bb0f9363f5..c8052a141b08 100644
--- a/arch/x86/boot/compressed/efi_thunk_64.S
+++ b/arch/x86/boot/compressed/efi_thunk_64.S
@@ -89,7 +89,7 @@ SYM_FUNC_START(__efi64_thunk)

pop %rbx
pop %rbp
- ret
+ RET
SYM_FUNC_END(__efi64_thunk)

.code32
diff --git a/arch/x86/boot/compressed/head_64.S b/arch/x86/boot/compressed/head_64.S
index 72f655c238cf..b55e2007b30c 100644
--- a/arch/x86/boot/compressed/head_64.S
+++ b/arch/x86/boot/compressed/head_64.S
@@ -786,7 +786,7 @@ SYM_FUNC_START(efi32_pe_entry)
2: popl %edi // restore callee-save registers
popl %ebx
leave
- ret
+ RET
SYM_FUNC_END(efi32_pe_entry)

.section ".rodata"
@@ -868,7 +868,7 @@ SYM_FUNC_START(startup32_check_sev_cbit)
popl %ebx
popl %eax
#endif
- ret
+ RET
SYM_FUNC_END(startup32_check_sev_cbit)

/*
diff --git a/arch/x86/boot/compressed/mem_encrypt.S b/arch/x86/boot/compressed/mem_encrypt.S
index a6dea4e8a082..484a9c06f41d 100644
--- a/arch/x86/boot/compressed/mem_encrypt.S
+++ b/arch/x86/boot/compressed/mem_encrypt.S
@@ -58,7 +58,7 @@ SYM_FUNC_START(get_sev_encryption_bit)

#endif /* CONFIG_AMD_MEM_ENCRYPT */

- ret
+ RET
SYM_FUNC_END(get_sev_encryption_bit)

.code64
@@ -99,7 +99,7 @@ SYM_FUNC_START(set_sev_encryption_mask)
#endif

xor %rax, %rax
- ret
+ RET
SYM_FUNC_END(set_sev_encryption_mask)

.data
diff --git a/arch/x86/crypto/aegis128-aesni-asm.S b/arch/x86/crypto/aegis128-aesni-asm.S
index 51d46d93efbc..b48ddebb4748 100644
--- a/arch/x86/crypto/aegis128-aesni-asm.S
+++ b/arch/x86/crypto/aegis128-aesni-asm.S
@@ -122,7 +122,7 @@ SYM_FUNC_START_LOCAL(__load_partial)
pxor T0, MSG

.Lld_partial_8:
- ret
+ RET
SYM_FUNC_END(__load_partial)

/*
@@ -180,7 +180,7 @@ SYM_FUNC_START_LOCAL(__store_partial)
mov %r10b, (%r9)

.Lst_partial_1:
- ret
+ RET
SYM_FUNC_END(__store_partial)

/*
@@ -225,7 +225,7 @@ SYM_FUNC_START(crypto_aegis128_aesni_init)
movdqu STATE4, 0x40(STATEP)

FRAME_END
- ret
+ RET
SYM_FUNC_END(crypto_aegis128_aesni_init)

/*
@@ -337,7 +337,7 @@ SYM_FUNC_START(crypto_aegis128_aesni_ad)
movdqu STATE3, 0x30(STATEP)
movdqu STATE4, 0x40(STATEP)
FRAME_END
- ret
+ RET

.Lad_out_1:
movdqu STATE4, 0x00(STATEP)
@@ -346,7 +346,7 @@ SYM_FUNC_START(crypto_aegis128_aesni_ad)
movdqu STATE2, 0x30(STATEP)
movdqu STATE3, 0x40(STATEP)
FRAME_END
- ret
+ RET

.Lad_out_2:
movdqu STATE3, 0x00(STATEP)
@@ -355,7 +355,7 @@ SYM_FUNC_START(crypto_aegis128_aesni_ad)
movdqu STATE1, 0x30(STATEP)
movdqu STATE2, 0x40(STATEP)
FRAME_END
- ret
+ RET

.Lad_out_3:
movdqu STATE2, 0x00(STATEP)
@@ -364,7 +364,7 @@ SYM_FUNC_START(crypto_aegis128_aesni_ad)
movdqu STATE0, 0x30(STATEP)
movdqu STATE1, 0x40(STATEP)
FRAME_END
- ret
+ RET

.Lad_out_4:
movdqu STATE1, 0x00(STATEP)
@@ -373,11 +373,11 @@ SYM_FUNC_START(crypto_aegis128_aesni_ad)
movdqu STATE4, 0x30(STATEP)
movdqu STATE0, 0x40(STATEP)
FRAME_END
- ret
+ RET

.Lad_out:
FRAME_END
- ret
+ RET
SYM_FUNC_END(crypto_aegis128_aesni_ad)

.macro encrypt_block a s0 s1 s2 s3 s4 i
@@ -452,7 +452,7 @@ SYM_FUNC_START(crypto_aegis128_aesni_enc)
movdqu STATE2, 0x30(STATEP)
movdqu STATE3, 0x40(STATEP)
FRAME_END
- ret
+ RET

.Lenc_out_1:
movdqu STATE3, 0x00(STATEP)
@@ -461,7 +461,7 @@ SYM_FUNC_START(crypto_aegis128_aesni_enc)
movdqu STATE1, 0x30(STATEP)
movdqu STATE2, 0x40(STATEP)
FRAME_END
- ret
+ RET

.Lenc_out_2:
movdqu STATE2, 0x00(STATEP)
@@ -470,7 +470,7 @@ SYM_FUNC_START(crypto_aegis128_aesni_enc)
movdqu STATE0, 0x30(STATEP)
movdqu STATE1, 0x40(STATEP)
FRAME_END
- ret
+ RET

.Lenc_out_3:
movdqu STATE1, 0x00(STATEP)
@@ -479,7 +479,7 @@ SYM_FUNC_START(crypto_aegis128_aesni_enc)
movdqu STATE4, 0x30(STATEP)
movdqu STATE0, 0x40(STATEP)
FRAME_END
- ret
+ RET

.Lenc_out_4:
movdqu STATE0, 0x00(STATEP)
@@ -488,11 +488,11 @@ SYM_FUNC_START(crypto_aegis128_aesni_enc)
movdqu STATE3, 0x30(STATEP)
movdqu STATE4, 0x40(STATEP)
FRAME_END
- ret
+ RET

.Lenc_out:
FRAME_END
- ret
+ RET
SYM_FUNC_END(crypto_aegis128_aesni_enc)

/*
@@ -532,7 +532,7 @@ SYM_FUNC_START(crypto_aegis128_aesni_enc_tail)
movdqu STATE3, 0x40(STATEP)

FRAME_END
- ret
+ RET
SYM_FUNC_END(crypto_aegis128_aesni_enc_tail)

.macro decrypt_block a s0 s1 s2 s3 s4 i
@@ -606,7 +606,7 @@ SYM_FUNC_START(crypto_aegis128_aesni_dec)
movdqu STATE2, 0x30(STATEP)
movdqu STATE3, 0x40(STATEP)
FRAME_END
- ret
+ RET

.Ldec_out_1:
movdqu STATE3, 0x00(STATEP)
@@ -615,7 +615,7 @@ SYM_FUNC_START(crypto_aegis128_aesni_dec)
movdqu STATE1, 0x30(STATEP)
movdqu STATE2, 0x40(STATEP)
FRAME_END
- ret
+ RET

.Ldec_out_2:
movdqu STATE2, 0x00(STATEP)
@@ -624,7 +624,7 @@ SYM_FUNC_START(crypto_aegis128_aesni_dec)
movdqu STATE0, 0x30(STATEP)
movdqu STATE1, 0x40(STATEP)
FRAME_END
- ret
+ RET

.Ldec_out_3:
movdqu STATE1, 0x00(STATEP)
@@ -633,7 +633,7 @@ SYM_FUNC_START(crypto_aegis128_aesni_dec)
movdqu STATE4, 0x30(STATEP)
movdqu STATE0, 0x40(STATEP)
FRAME_END
- ret
+ RET

.Ldec_out_4:
movdqu STATE0, 0x00(STATEP)
@@ -642,11 +642,11 @@ SYM_FUNC_START(crypto_aegis128_aesni_dec)
movdqu STATE3, 0x30(STATEP)
movdqu STATE4, 0x40(STATEP)
FRAME_END
- ret
+ RET

.Ldec_out:
FRAME_END
- ret
+ RET
SYM_FUNC_END(crypto_aegis128_aesni_dec)

/*
@@ -696,7 +696,7 @@ SYM_FUNC_START(crypto_aegis128_aesni_dec_tail)
movdqu STATE3, 0x40(STATEP)

FRAME_END
- ret
+ RET
SYM_FUNC_END(crypto_aegis128_aesni_dec_tail)

/*
@@ -743,5 +743,5 @@ SYM_FUNC_START(crypto_aegis128_aesni_final)
movdqu MSG, (%rsi)

FRAME_END
- ret
+ RET
SYM_FUNC_END(crypto_aegis128_aesni_final)
diff --git a/arch/x86/crypto/aes_ctrby8_avx-x86_64.S b/arch/x86/crypto/aes_ctrby8_avx-x86_64.S
index 3f0fc7dd87d7..c799838242a6 100644
--- a/arch/x86/crypto/aes_ctrby8_avx-x86_64.S
+++ b/arch/x86/crypto/aes_ctrby8_avx-x86_64.S
@@ -525,7 +525,7 @@ ddq_add_8:
/* return updated IV */
vpshufb xbyteswap, xcounter, xcounter
vmovdqu xcounter, (p_iv)
- ret
+ RET
.endm

/*
diff --git a/arch/x86/crypto/aesni-intel_asm.S b/arch/x86/crypto/aesni-intel_asm.S
index 57aef3f5a81e..69c7c0dc22ea 100644
--- a/arch/x86/crypto/aesni-intel_asm.S
+++ b/arch/x86/crypto/aesni-intel_asm.S
@@ -1598,7 +1598,7 @@ SYM_FUNC_START(aesni_gcm_dec)
GCM_ENC_DEC dec
GCM_COMPLETE arg10, arg11
FUNC_RESTORE
- ret
+ RET
SYM_FUNC_END(aesni_gcm_dec)

@@ -1687,7 +1687,7 @@ SYM_FUNC_START(aesni_gcm_enc)

GCM_COMPLETE arg10, arg11
FUNC_RESTORE
- ret
+ RET
SYM_FUNC_END(aesni_gcm_enc)

/*****************************************************************************
@@ -1705,7 +1705,7 @@ SYM_FUNC_START(aesni_gcm_init)
FUNC_SAVE
GCM_INIT %arg3, %arg4,%arg5, %arg6
FUNC_RESTORE
- ret
+ RET
SYM_FUNC_END(aesni_gcm_init)

/*****************************************************************************
@@ -1720,7 +1720,7 @@ SYM_FUNC_START(aesni_gcm_enc_update)
FUNC_SAVE
GCM_ENC_DEC enc
FUNC_RESTORE
- ret
+ RET
SYM_FUNC_END(aesni_gcm_enc_update)

/*****************************************************************************
@@ -1735,7 +1735,7 @@ SYM_FUNC_START(aesni_gcm_dec_update)
FUNC_SAVE
GCM_ENC_DEC dec
FUNC_RESTORE
- ret
+ RET
SYM_FUNC_END(aesni_gcm_dec_update)

/*****************************************************************************
@@ -1750,7 +1750,7 @@ SYM_FUNC_START(aesni_gcm_finalize)
FUNC_SAVE
GCM_COMPLETE %arg3 %arg4
FUNC_RESTORE
- ret
+ RET
SYM_FUNC_END(aesni_gcm_finalize)

#endif
@@ -1766,7 +1766,7 @@ SYM_FUNC_START_LOCAL(_key_expansion_256a)
pxor %xmm1, %xmm0
movaps %xmm0, (TKEYP)
add $0x10, TKEYP
- ret
+ RET
SYM_FUNC_END(_key_expansion_256a)
SYM_FUNC_END_ALIAS(_key_expansion_128)

@@ -1791,7 +1791,7 @@ SYM_FUNC_START_LOCAL(_key_expansion_192a)
shufps $0b01001110, %xmm2, %xmm1
movaps %xmm1, 0x10(TKEYP)
add $0x20, TKEYP
- ret
+ RET
SYM_FUNC_END(_key_expansion_192a)

SYM_FUNC_START_LOCAL(_key_expansion_192b)
@@ -1810,7 +1810,7 @@ SYM_FUNC_START_LOCAL(_key_expansion_192b)

movaps %xmm0, (TKEYP)
add $0x10, TKEYP
- ret
+ RET
SYM_FUNC_END(_key_expansion_192b)

SYM_FUNC_START_LOCAL(_key_expansion_256b)
@@ -1822,7 +1822,7 @@ SYM_FUNC_START_LOCAL(_key_expansion_256b)
pxor %xmm1, %xmm2
movaps %xmm2, (TKEYP)
add $0x10, TKEYP
- ret
+ RET
SYM_FUNC_END(_key_expansion_256b)

/*
@@ -1937,7 +1937,7 @@ SYM_FUNC_START(aesni_set_key)
popl KEYP
#endif
FRAME_END
- ret
+ RET
SYM_FUNC_END(aesni_set_key)

/*
@@ -1961,7 +1961,7 @@ SYM_FUNC_START(aesni_enc)
popl KEYP
#endif
FRAME_END
- ret
+ RET
SYM_FUNC_END(aesni_enc)

/*
@@ -2018,7 +2018,7 @@ SYM_FUNC_START_LOCAL(_aesni_enc1)
aesenc KEY, STATE
movaps 0x70(TKEYP), KEY
aesenclast KEY, STATE
- ret
+ RET
SYM_FUNC_END(_aesni_enc1)

/*
@@ -2126,7 +2126,7 @@ SYM_FUNC_START_LOCAL(_aesni_enc4)
aesenclast KEY, STATE2
aesenclast KEY, STATE3
aesenclast KEY, STATE4
- ret
+ RET
SYM_FUNC_END(_aesni_enc4)

/*
@@ -2151,7 +2151,7 @@ SYM_FUNC_START(aesni_dec)
popl KEYP
#endif
FRAME_END
- ret
+ RET
SYM_FUNC_END(aesni_dec)

/*
@@ -2208,7 +2208,7 @@ SYM_FUNC_START_LOCAL(_aesni_dec1)
aesdec KEY, STATE
movaps 0x70(TKEYP), KEY
aesdeclast KEY, STATE
- ret
+ RET
SYM_FUNC_END(_aesni_dec1)

/*
@@ -2316,7 +2316,7 @@ SYM_FUNC_START_LOCAL(_aesni_dec4)
aesdeclast KEY, STATE2
aesdeclast KEY, STATE3
aesdeclast KEY, STATE4
- ret
+ RET
SYM_FUNC_END(_aesni_dec4)

/*
@@ -2376,7 +2376,7 @@ SYM_FUNC_START(aesni_ecb_enc)
popl LEN
#endif
FRAME_END
- ret
+ RET
SYM_FUNC_END(aesni_ecb_enc)

/*
@@ -2437,7 +2437,7 @@ SYM_FUNC_START(aesni_ecb_dec)
popl LEN
#endif
FRAME_END
- ret
+ RET
SYM_FUNC_END(aesni_ecb_dec)

/*
@@ -2481,7 +2481,7 @@ SYM_FUNC_START(aesni_cbc_enc)
popl IVP
#endif
FRAME_END
- ret
+ RET
SYM_FUNC_END(aesni_cbc_enc)

/*
@@ -2574,7 +2574,7 @@ SYM_FUNC_START(aesni_cbc_dec)
popl IVP
#endif
FRAME_END
- ret
+ RET
SYM_FUNC_END(aesni_cbc_dec)

#ifdef __x86_64__
@@ -2602,7 +2602,7 @@ SYM_FUNC_START_LOCAL(_aesni_inc_init)
mov $1, TCTR_LOW
movq TCTR_LOW, INC
movq CTR, TCTR_LOW
- ret
+ RET
SYM_FUNC_END(_aesni_inc_init)

/*
@@ -2630,7 +2630,7 @@ SYM_FUNC_START_LOCAL(_aesni_inc)
.Linc_low:
movaps CTR, IV
pshufb BSWAP_MASK, IV
- ret
+ RET
SYM_FUNC_END(_aesni_inc)

/*
@@ -2693,7 +2693,7 @@ SYM_FUNC_START(aesni_ctr_enc)
movups IV, (IVP)
.Lctr_enc_just_ret:
FRAME_END
- ret
+ RET
SYM_FUNC_END(aesni_ctr_enc)

/*
@@ -2778,7 +2778,7 @@ SYM_FUNC_START(aesni_xts_encrypt)
movups IV, (IVP)

FRAME_END
- ret
+ RET
SYM_FUNC_END(aesni_xts_encrypt)

/*
@@ -2846,7 +2846,7 @@ SYM_FUNC_START(aesni_xts_decrypt)
movups IV, (IVP)

FRAME_END
- ret
+ RET
SYM_FUNC_END(aesni_xts_decrypt)

#endif
diff --git a/arch/x86/crypto/aesni-intel_avx-x86_64.S b/arch/x86/crypto/aesni-intel_avx-x86_64.S
index 2cf8e94d986a..4d9b2f887064 100644
--- a/arch/x86/crypto/aesni-intel_avx-x86_64.S
+++ b/arch/x86/crypto/aesni-intel_avx-x86_64.S
@@ -1777,7 +1777,7 @@ SYM_FUNC_START(aesni_gcm_init_avx_gen2)
FUNC_SAVE
INIT GHASH_MUL_AVX, PRECOMPUTE_AVX
FUNC_RESTORE
- ret
+ RET
SYM_FUNC_END(aesni_gcm_init_avx_gen2)

###############################################################################
@@ -1798,15 +1798,15 @@ SYM_FUNC_START(aesni_gcm_enc_update_avx_gen2)
# must be 192
GCM_ENC_DEC INITIAL_BLOCKS_AVX, GHASH_8_ENCRYPT_8_PARALLEL_AVX, GHASH_LAST_8_AVX, GHASH_MUL_AVX, ENC, 11
FUNC_RESTORE
- ret
+ RET
key_128_enc_update:
GCM_ENC_DEC INITIAL_BLOCKS_AVX, GHASH_8_ENCRYPT_8_PARALLEL_AVX, GHASH_LAST_8_AVX, GHASH_MUL_AVX, ENC, 9
FUNC_RESTORE
- ret
+ RET
key_256_enc_update:
GCM_ENC_DEC INITIAL_BLOCKS_AVX, GHASH_8_ENCRYPT_8_PARALLEL_AVX, GHASH_LAST_8_AVX, GHASH_MUL_AVX, ENC, 13
FUNC_RESTORE
- ret
+ RET
SYM_FUNC_END(aesni_gcm_enc_update_avx_gen2)

###############################################################################
@@ -1827,15 +1827,15 @@ SYM_FUNC_START(aesni_gcm_dec_update_avx_gen2)
# must be 192
GCM_ENC_DEC INITIAL_BLOCKS_AVX, GHASH_8_ENCRYPT_8_PARALLEL_AVX, GHASH_LAST_8_AVX, GHASH_MUL_AVX, DEC, 11
FUNC_RESTORE
- ret
+ RET
key_128_dec_update:
GCM_ENC_DEC INITIAL_BLOCKS_AVX, GHASH_8_ENCRYPT_8_PARALLEL_AVX, GHASH_LAST_8_AVX, GHASH_MUL_AVX, DEC, 9
FUNC_RESTORE
- ret
+ RET
key_256_dec_update:
GCM_ENC_DEC INITIAL_BLOCKS_AVX, GHASH_8_ENCRYPT_8_PARALLEL_AVX, GHASH_LAST_8_AVX, GHASH_MUL_AVX, DEC, 13
FUNC_RESTORE
- ret
+ RET
SYM_FUNC_END(aesni_gcm_dec_update_avx_gen2)

###############################################################################
@@ -1856,15 +1856,15 @@ SYM_FUNC_START(aesni_gcm_finalize_avx_gen2)
# must be 192
GCM_COMPLETE GHASH_MUL_AVX, 11, arg3, arg4
FUNC_RESTORE
- ret
+ RET
key_128_finalize:
GCM_COMPLETE GHASH_MUL_AVX, 9, arg3, arg4
FUNC_RESTORE
- ret
+ RET
key_256_finalize:
GCM_COMPLETE GHASH_MUL_AVX, 13, arg3, arg4
FUNC_RESTORE
- ret
+ RET
SYM_FUNC_END(aesni_gcm_finalize_avx_gen2)

###############################################################################
@@ -2745,7 +2745,7 @@ SYM_FUNC_START(aesni_gcm_init_avx_gen4)
FUNC_SAVE
INIT GHASH_MUL_AVX2, PRECOMPUTE_AVX2
FUNC_RESTORE
- ret
+ RET
SYM_FUNC_END(aesni_gcm_init_avx_gen4)

###############################################################################
@@ -2766,15 +2766,15 @@ SYM_FUNC_START(aesni_gcm_enc_update_avx_gen4)
# must be 192
GCM_ENC_DEC INITIAL_BLOCKS_AVX2, GHASH_8_ENCRYPT_8_PARALLEL_AVX2, GHASH_LAST_8_AVX2, GHASH_MUL_AVX2, ENC, 11
FUNC_RESTORE
- ret
+ RET
key_128_enc_update4:
GCM_ENC_DEC INITIAL_BLOCKS_AVX2, GHASH_8_ENCRYPT_8_PARALLEL_AVX2, GHASH_LAST_8_AVX2, GHASH_MUL_AVX2, ENC, 9
FUNC_RESTORE
- ret
+ RET
key_256_enc_update4:
GCM_ENC_DEC INITIAL_BLOCKS_AVX2, GHASH_8_ENCRYPT_8_PARALLEL_AVX2, GHASH_LAST_8_AVX2, GHASH_MUL_AVX2, ENC, 13
FUNC_RESTORE
- ret
+ RET
SYM_FUNC_END(aesni_gcm_enc_update_avx_gen4)

###############################################################################
@@ -2795,15 +2795,15 @@ SYM_FUNC_START(aesni_gcm_dec_update_avx_gen4)
# must be 192
GCM_ENC_DEC INITIAL_BLOCKS_AVX2, GHASH_8_ENCRYPT_8_PARALLEL_AVX2, GHASH_LAST_8_AVX2, GHASH_MUL_AVX2, DEC, 11
FUNC_RESTORE
- ret
+ RET
key_128_dec_update4:
GCM_ENC_DEC INITIAL_BLOCKS_AVX2, GHASH_8_ENCRYPT_8_PARALLEL_AVX2, GHASH_LAST_8_AVX2, GHASH_MUL_AVX2, DEC, 9
FUNC_RESTORE
- ret
+ RET
key_256_dec_update4:
GCM_ENC_DEC INITIAL_BLOCKS_AVX2, GHASH_8_ENCRYPT_8_PARALLEL_AVX2, GHASH_LAST_8_AVX2, GHASH_MUL_AVX2, DEC, 13
FUNC_RESTORE
- ret
+ RET
SYM_FUNC_END(aesni_gcm_dec_update_avx_gen4)

###############################################################################
@@ -2824,13 +2824,13 @@ SYM_FUNC_START(aesni_gcm_finalize_avx_gen4)
# must be 192
GCM_COMPLETE GHASH_MUL_AVX2, 11, arg3, arg4
FUNC_RESTORE
- ret
+ RET
key_128_finalize4:
GCM_COMPLETE GHASH_MUL_AVX2, 9, arg3, arg4
FUNC_RESTORE
- ret
+ RET
key_256_finalize4:
GCM_COMPLETE GHASH_MUL_AVX2, 13, arg3, arg4
FUNC_RESTORE
- ret
+ RET
SYM_FUNC_END(aesni_gcm_finalize_avx_gen4)
diff --git a/arch/x86/crypto/blake2s-core.S b/arch/x86/crypto/blake2s-core.S
index 2ca79974f819..b50b35ff1fdb 100644
--- a/arch/x86/crypto/blake2s-core.S
+++ b/arch/x86/crypto/blake2s-core.S
@@ -171,7 +171,7 @@ SYM_FUNC_START(blake2s_compress_ssse3)
movdqu %xmm1,0x10(%rdi)
movdqu %xmm14,0x20(%rdi)
.Lendofloop:
- ret
+ RET
SYM_FUNC_END(blake2s_compress_ssse3)

#ifdef CONFIG_AS_AVX512
@@ -251,6 +251,6 @@ SYM_FUNC_START(blake2s_compress_avx512)
vmovdqu %xmm1,0x10(%rdi)
vmovdqu %xmm4,0x20(%rdi)
vzeroupper
- retq
+ RET
SYM_FUNC_END(blake2s_compress_avx512)
#endif /* CONFIG_AS_AVX512 */
diff --git a/arch/x86/crypto/blowfish-x86_64-asm_64.S b/arch/x86/crypto/blowfish-x86_64-asm_64.S
index 4222ac6d6584..802d71582689 100644
--- a/arch/x86/crypto/blowfish-x86_64-asm_64.S
+++ b/arch/x86/crypto/blowfish-x86_64-asm_64.S
@@ -135,10 +135,10 @@ SYM_FUNC_START(__blowfish_enc_blk)
jnz .L__enc_xor;

write_block();
- ret;
+ RET;
.L__enc_xor:
xor_block();
- ret;
+ RET;
SYM_FUNC_END(__blowfish_enc_blk)

SYM_FUNC_START(blowfish_dec_blk)
@@ -170,7 +170,7 @@ SYM_FUNC_START(blowfish_dec_blk)

movq %r11, %r12;

- ret;
+ RET;
SYM_FUNC_END(blowfish_dec_blk)

/**********************************************************************
@@ -322,14 +322,14 @@ SYM_FUNC_START(__blowfish_enc_blk_4way)

popq %rbx;
popq %r12;
- ret;
+ RET;

.L__enc_xor4:
xor_block4();

popq %rbx;
popq %r12;
- ret;
+ RET;
SYM_FUNC_END(__blowfish_enc_blk_4way)

SYM_FUNC_START(blowfish_dec_blk_4way)
@@ -364,5 +364,5 @@ SYM_FUNC_START(blowfish_dec_blk_4way)
popq %rbx;
popq %r12;

- ret;
+ RET;
SYM_FUNC_END(blowfish_dec_blk_4way)
diff --git a/arch/x86/crypto/camellia-aesni-avx-asm_64.S b/arch/x86/crypto/camellia-aesni-avx-asm_64.S
index ecc0a9a905c4..297b1a7ed2bc 100644
--- a/arch/x86/crypto/camellia-aesni-avx-asm_64.S
+++ b/arch/x86/crypto/camellia-aesni-avx-asm_64.S
@@ -193,7 +193,7 @@ SYM_FUNC_START_LOCAL(roundsm16_x0_x1_x2_x3_x4_x5_x6_x7_y0_y1_y2_y3_y4_y5_y6_y7_c
roundsm16(%xmm0, %xmm1, %xmm2, %xmm3, %xmm4, %xmm5, %xmm6, %xmm7,
%xmm8, %xmm9, %xmm10, %xmm11, %xmm12, %xmm13, %xmm14, %xmm15,
%rcx, (%r9));
- ret;
+ RET;
SYM_FUNC_END(roundsm16_x0_x1_x2_x3_x4_x5_x6_x7_y0_y1_y2_y3_y4_y5_y6_y7_cd)

.align 8
@@ -201,7 +201,7 @@ SYM_FUNC_START_LOCAL(roundsm16_x4_x5_x6_x7_x0_x1_x2_x3_y4_y5_y6_y7_y0_y1_y2_y3_a
roundsm16(%xmm4, %xmm5, %xmm6, %xmm7, %xmm0, %xmm1, %xmm2, %xmm3,
%xmm12, %xmm13, %xmm14, %xmm15, %xmm8, %xmm9, %xmm10, %xmm11,
%rax, (%r9));
- ret;
+ RET;
SYM_FUNC_END(roundsm16_x4_x5_x6_x7_x0_x1_x2_x3_y4_y5_y6_y7_y0_y1_y2_y3_ab)

/*
@@ -787,7 +787,7 @@ SYM_FUNC_START_LOCAL(__camellia_enc_blk16)
%xmm15, (key_table)(CTX, %r8, 8), (%rax), 1 * 16(%rax));

FRAME_END
- ret;
+ RET;

.align 8
.Lenc_max32:
@@ -874,7 +874,7 @@ SYM_FUNC_START_LOCAL(__camellia_dec_blk16)
%xmm15, (key_table)(CTX), (%rax), 1 * 16(%rax));

FRAME_END
- ret;
+ RET;

.align 8
.Ldec_max32:
@@ -915,7 +915,7 @@ SYM_FUNC_START(camellia_ecb_enc_16way)
%xmm8, %rsi);

FRAME_END
- ret;
+ RET;
SYM_FUNC_END(camellia_ecb_enc_16way)

SYM_FUNC_START(camellia_ecb_dec_16way)
@@ -945,7 +945,7 @@ SYM_FUNC_START(camellia_ecb_dec_16way)
%xmm8, %rsi);

FRAME_END
- ret;
+ RET;
SYM_FUNC_END(camellia_ecb_dec_16way)

SYM_FUNC_START(camellia_cbc_dec_16way)
@@ -996,7 +996,7 @@ SYM_FUNC_START(camellia_cbc_dec_16way)
%xmm8, %rsi);

FRAME_END
- ret;
+ RET;
SYM_FUNC_END(camellia_cbc_dec_16way)

#define inc_le128(x, minus_one, tmp) \
@@ -1109,7 +1109,7 @@ SYM_FUNC_START(camellia_ctr_16way)
%xmm8, %rsi);

FRAME_END
- ret;
+ RET;
SYM_FUNC_END(camellia_ctr_16way)

#define gf128mul_x_ble(iv, mask, tmp) \
@@ -1253,7 +1253,7 @@ SYM_FUNC_START_LOCAL(camellia_xts_crypt_16way)
%xmm8, %rsi);

FRAME_END
- ret;
+ RET;
SYM_FUNC_END(camellia_xts_crypt_16way)

SYM_FUNC_START(camellia_xts_enc_16way)
diff --git a/arch/x86/crypto/camellia-aesni-avx2-asm_64.S b/arch/x86/crypto/camellia-aesni-avx2-asm_64.S
index 0907243c501c..288cd246da20 100644
--- a/arch/x86/crypto/camellia-aesni-avx2-asm_64.S
+++ b/arch/x86/crypto/camellia-aesni-avx2-asm_64.S
@@ -227,7 +227,7 @@ SYM_FUNC_START_LOCAL(roundsm32_x0_x1_x2_x3_x4_x5_x6_x7_y0_y1_y2_y3_y4_y5_y6_y7_c
roundsm32(%ymm0, %ymm1, %ymm2, %ymm3, %ymm4, %ymm5, %ymm6, %ymm7,
%ymm8, %ymm9, %ymm10, %ymm11, %ymm12, %ymm13, %ymm14, %ymm15,
%rcx, (%r9));
- ret;
+ RET;
SYM_FUNC_END(roundsm32_x0_x1_x2_x3_x4_x5_x6_x7_y0_y1_y2_y3_y4_y5_y6_y7_cd)

.align 8
@@ -235,7 +235,7 @@ SYM_FUNC_START_LOCAL(roundsm32_x4_x5_x6_x7_x0_x1_x2_x3_y4_y5_y6_y7_y0_y1_y2_y3_a
roundsm32(%ymm4, %ymm5, %ymm6, %ymm7, %ymm0, %ymm1, %ymm2, %ymm3,
%ymm12, %ymm13, %ymm14, %ymm15, %ymm8, %ymm9, %ymm10, %ymm11,
%rax, (%r9));
- ret;
+ RET;
SYM_FUNC_END(roundsm32_x4_x5_x6_x7_x0_x1_x2_x3_y4_y5_y6_y7_y0_y1_y2_y3_ab)

/*
@@ -825,7 +825,7 @@ SYM_FUNC_START_LOCAL(__camellia_enc_blk32)
%ymm15, (key_table)(CTX, %r8, 8), (%rax), 1 * 32(%rax));

FRAME_END
- ret;
+ RET;

.align 8
.Lenc_max32:
@@ -912,7 +912,7 @@ SYM_FUNC_START_LOCAL(__camellia_dec_blk32)
%ymm15, (key_table)(CTX), (%rax), 1 * 32(%rax));

FRAME_END
- ret;
+ RET;

.align 8
.Ldec_max32:
@@ -957,7 +957,7 @@ SYM_FUNC_START(camellia_ecb_enc_32way)
vzeroupper;

FRAME_END
- ret;
+ RET;
SYM_FUNC_END(camellia_ecb_enc_32way)

SYM_FUNC_START(camellia_ecb_dec_32way)
@@ -991,7 +991,7 @@ SYM_FUNC_START(camellia_ecb_dec_32way)
vzeroupper;

FRAME_END
- ret;
+ RET;
SYM_FUNC_END(camellia_ecb_dec_32way)

SYM_FUNC_START(camellia_cbc_dec_32way)
@@ -1059,7 +1059,7 @@ SYM_FUNC_START(camellia_cbc_dec_32way)
vzeroupper;

FRAME_END
- ret;
+ RET;
SYM_FUNC_END(camellia_cbc_dec_32way)

#define inc_le128(x, minus_one, tmp) \
@@ -1199,7 +1199,7 @@ SYM_FUNC_START(camellia_ctr_32way)
vzeroupper;

FRAME_END
- ret;
+ RET;
SYM_FUNC_END(camellia_ctr_32way)

#define gf128mul_x_ble(iv, mask, tmp) \
@@ -1366,7 +1366,7 @@ SYM_FUNC_START_LOCAL(camellia_xts_crypt_32way)
vzeroupper;

FRAME_END
- ret;
+ RET;
SYM_FUNC_END(camellia_xts_crypt_32way)

SYM_FUNC_START(camellia_xts_enc_32way)
diff --git a/arch/x86/crypto/camellia-x86_64-asm_64.S b/arch/x86/crypto/camellia-x86_64-asm_64.S
index 1372e6408850..347c059f5940 100644
--- a/arch/x86/crypto/camellia-x86_64-asm_64.S
+++ b/arch/x86/crypto/camellia-x86_64-asm_64.S
@@ -213,13 +213,13 @@ SYM_FUNC_START(__camellia_enc_blk)
enc_outunpack(mov, RT1);

movq RR12, %r12;
- ret;
+ RET;

.L__enc_xor:
enc_outunpack(xor, RT1);

movq RR12, %r12;
- ret;
+ RET;
SYM_FUNC_END(__camellia_enc_blk)

SYM_FUNC_START(camellia_dec_blk)
@@ -257,7 +257,7 @@ SYM_FUNC_START(camellia_dec_blk)
dec_outunpack();

movq RR12, %r12;
- ret;
+ RET;
SYM_FUNC_END(camellia_dec_blk)

/**********************************************************************
@@ -448,14 +448,14 @@ SYM_FUNC_START(__camellia_enc_blk_2way)

movq RR12, %r12;
popq %rbx;
- ret;
+ RET;

.L__enc2_xor:
enc_outunpack2(xor, RT2);

movq RR12, %r12;
popq %rbx;
- ret;
+ RET;
SYM_FUNC_END(__camellia_enc_blk_2way)

SYM_FUNC_START(camellia_dec_blk_2way)
@@ -495,5 +495,5 @@ SYM_FUNC_START(camellia_dec_blk_2way)

movq RR12, %r12;
movq RXOR, %rbx;
- ret;
+ RET;
SYM_FUNC_END(camellia_dec_blk_2way)
diff --git a/arch/x86/crypto/cast5-avx-x86_64-asm_64.S b/arch/x86/crypto/cast5-avx-x86_64-asm_64.S
index 8a6181b08b59..b258af420c92 100644
--- a/arch/x86/crypto/cast5-avx-x86_64-asm_64.S
+++ b/arch/x86/crypto/cast5-avx-x86_64-asm_64.S
@@ -279,7 +279,7 @@ SYM_FUNC_START_LOCAL(__cast5_enc_blk16)
outunpack_blocks(RR3, RL3, RTMP, RX, RKM);
outunpack_blocks(RR4, RL4, RTMP, RX, RKM);

- ret;
+ RET;
SYM_FUNC_END(__cast5_enc_blk16)

.align 16
@@ -352,7 +352,7 @@ SYM_FUNC_START_LOCAL(__cast5_dec_blk16)
outunpack_blocks(RR3, RL3, RTMP, RX, RKM);
outunpack_blocks(RR4, RL4, RTMP, RX, RKM);

- ret;
+ RET;

.L__skip_dec:
vpsrldq $4, RKR, RKR;
@@ -393,7 +393,7 @@ SYM_FUNC_START(cast5_ecb_enc_16way)

popq %r15;
FRAME_END
- ret;
+ RET;
SYM_FUNC_END(cast5_ecb_enc_16way)

SYM_FUNC_START(cast5_ecb_dec_16way)
@@ -431,7 +431,7 @@ SYM_FUNC_START(cast5_ecb_dec_16way)

popq %r15;
FRAME_END
- ret;
+ RET;
SYM_FUNC_END(cast5_ecb_dec_16way)

SYM_FUNC_START(cast5_cbc_dec_16way)
@@ -483,7 +483,7 @@ SYM_FUNC_START(cast5_cbc_dec_16way)
popq %r15;
popq %r12;
FRAME_END
- ret;
+ RET;
SYM_FUNC_END(cast5_cbc_dec_16way)

SYM_FUNC_START(cast5_ctr_16way)
@@ -559,5 +559,5 @@ SYM_FUNC_START(cast5_ctr_16way)
popq %r15;
popq %r12;
FRAME_END
- ret;
+ RET;
SYM_FUNC_END(cast5_ctr_16way)
diff --git a/arch/x86/crypto/cast6-avx-x86_64-asm_64.S b/arch/x86/crypto/cast6-avx-x86_64-asm_64.S
index 932a3ce32a88..6eccaf1fb4c6 100644
--- a/arch/x86/crypto/cast6-avx-x86_64-asm_64.S
+++ b/arch/x86/crypto/cast6-avx-x86_64-asm_64.S
@@ -291,7 +291,7 @@ SYM_FUNC_START_LOCAL(__cast6_enc_blk8)
outunpack_blocks(RA1, RB1, RC1, RD1, RTMP, RX, RKRF, RKM);
outunpack_blocks(RA2, RB2, RC2, RD2, RTMP, RX, RKRF, RKM);

- ret;
+ RET;
SYM_FUNC_END(__cast6_enc_blk8)

.align 8
@@ -338,7 +338,7 @@ SYM_FUNC_START_LOCAL(__cast6_dec_blk8)
outunpack_blocks(RA1, RB1, RC1, RD1, RTMP, RX, RKRF, RKM);
outunpack_blocks(RA2, RB2, RC2, RD2, RTMP, RX, RKRF, RKM);

- ret;
+ RET;
SYM_FUNC_END(__cast6_dec_blk8)

SYM_FUNC_START(cast6_ecb_enc_8way)
@@ -361,7 +361,7 @@ SYM_FUNC_START(cast6_ecb_enc_8way)

popq %r15;
FRAME_END
- ret;
+ RET;
SYM_FUNC_END(cast6_ecb_enc_8way)

SYM_FUNC_START(cast6_ecb_dec_8way)
@@ -384,7 +384,7 @@ SYM_FUNC_START(cast6_ecb_dec_8way)

popq %r15;
FRAME_END
- ret;
+ RET;
SYM_FUNC_END(cast6_ecb_dec_8way)

SYM_FUNC_START(cast6_cbc_dec_8way)
@@ -410,7 +410,7 @@ SYM_FUNC_START(cast6_cbc_dec_8way)
popq %r15;
popq %r12;
FRAME_END
- ret;
+ RET;
SYM_FUNC_END(cast6_cbc_dec_8way)

SYM_FUNC_START(cast6_ctr_8way)
@@ -438,7 +438,7 @@ SYM_FUNC_START(cast6_ctr_8way)
popq %r15;
popq %r12;
FRAME_END
- ret;
+ RET;
SYM_FUNC_END(cast6_ctr_8way)

SYM_FUNC_START(cast6_xts_enc_8way)
@@ -465,7 +465,7 @@ SYM_FUNC_START(cast6_xts_enc_8way)

popq %r15;
FRAME_END
- ret;
+ RET;
SYM_FUNC_END(cast6_xts_enc_8way)

SYM_FUNC_START(cast6_xts_dec_8way)
@@ -492,5 +492,5 @@ SYM_FUNC_START(cast6_xts_dec_8way)

popq %r15;
FRAME_END
- ret;
+ RET;
SYM_FUNC_END(cast6_xts_dec_8way)
diff --git a/arch/x86/crypto/chacha-avx2-x86_64.S b/arch/x86/crypto/chacha-avx2-x86_64.S
index ee9a40ab4109..f3d8fc018249 100644
--- a/arch/x86/crypto/chacha-avx2-x86_64.S
+++ b/arch/x86/crypto/chacha-avx2-x86_64.S
@@ -193,7 +193,7 @@ SYM_FUNC_START(chacha_2block_xor_avx2)

.Ldone2:
vzeroupper
- ret
+ RET

.Lxorpart2:
# xor remaining bytes from partial register into output
@@ -498,7 +498,7 @@ SYM_FUNC_START(chacha_4block_xor_avx2)

.Ldone4:
vzeroupper
- ret
+ RET

.Lxorpart4:
# xor remaining bytes from partial register into output
@@ -992,7 +992,7 @@ SYM_FUNC_START(chacha_8block_xor_avx2)
.Ldone8:
vzeroupper
lea -8(%r10),%rsp
- ret
+ RET

.Lxorpart8:
# xor remaining bytes from partial register into output
diff --git a/arch/x86/crypto/chacha-avx512vl-x86_64.S b/arch/x86/crypto/chacha-avx512vl-x86_64.S
index 8713c16c2501..259383e1ad44 100644
--- a/arch/x86/crypto/chacha-avx512vl-x86_64.S
+++ b/arch/x86/crypto/chacha-avx512vl-x86_64.S
@@ -166,7 +166,7 @@ SYM_FUNC_START(chacha_2block_xor_avx512vl)

.Ldone2:
vzeroupper
- ret
+ RET

.Lxorpart2:
# xor remaining bytes from partial register into output
@@ -432,7 +432,7 @@ SYM_FUNC_START(chacha_4block_xor_avx512vl)

.Ldone4:
vzeroupper
- ret
+ RET

.Lxorpart4:
# xor remaining bytes from partial register into output
@@ -812,7 +812,7 @@ SYM_FUNC_START(chacha_8block_xor_avx512vl)

.Ldone8:
vzeroupper
- ret
+ RET

.Lxorpart8:
# xor remaining bytes from partial register into output
diff --git a/arch/x86/crypto/chacha-ssse3-x86_64.S b/arch/x86/crypto/chacha-ssse3-x86_64.S
index ca1788bfee16..7111949cd5b9 100644
--- a/arch/x86/crypto/chacha-ssse3-x86_64.S
+++ b/arch/x86/crypto/chacha-ssse3-x86_64.S
@@ -108,7 +108,7 @@ SYM_FUNC_START_LOCAL(chacha_permute)
sub $2,%r8d
jnz .Ldoubleround

- ret
+ RET
SYM_FUNC_END(chacha_permute)

SYM_FUNC_START(chacha_block_xor_ssse3)
@@ -166,7 +166,7 @@ SYM_FUNC_START(chacha_block_xor_ssse3)

.Ldone:
FRAME_END
- ret
+ RET

.Lxorpart:
# xor remaining bytes from partial register into output
@@ -217,7 +217,7 @@ SYM_FUNC_START(hchacha_block_ssse3)
movdqu %xmm3,0x10(%rsi)

FRAME_END
- ret
+ RET
SYM_FUNC_END(hchacha_block_ssse3)

SYM_FUNC_START(chacha_4block_xor_ssse3)
@@ -762,7 +762,7 @@ SYM_FUNC_START(chacha_4block_xor_ssse3)

.Ldone4:
lea -8(%r10),%rsp
- ret
+ RET

.Lxorpart4:
# xor remaining bytes from partial register into output
diff --git a/arch/x86/crypto/crc32-pclmul_asm.S b/arch/x86/crypto/crc32-pclmul_asm.S
index 6e7d4c4d3208..c392a6edbfff 100644
--- a/arch/x86/crypto/crc32-pclmul_asm.S
+++ b/arch/x86/crypto/crc32-pclmul_asm.S
@@ -236,5 +236,5 @@ fold_64:
pxor %xmm2, %xmm1
pextrd $0x01, %xmm1, %eax

- ret
+ RET
SYM_FUNC_END(crc32_pclmul_le_16)
diff --git a/arch/x86/crypto/crc32c-pcl-intel-asm_64.S b/arch/x86/crypto/crc32c-pcl-intel-asm_64.S
index 884dc767b051..f6e3568fbd63 100644
--- a/arch/x86/crypto/crc32c-pcl-intel-asm_64.S
+++ b/arch/x86/crypto/crc32c-pcl-intel-asm_64.S
@@ -309,7 +309,7 @@ do_return:
popq %rsi
popq %rdi
popq %rbx
- ret
+ RET
SYM_FUNC_END(crc_pcl)

.section .rodata, "a", @progbits
diff --git a/arch/x86/crypto/crct10dif-pcl-asm_64.S b/arch/x86/crypto/crct10dif-pcl-asm_64.S
index b2533d63030e..721474abfb71 100644
--- a/arch/x86/crypto/crct10dif-pcl-asm_64.S
+++ b/arch/x86/crypto/crct10dif-pcl-asm_64.S
@@ -257,7 +257,7 @@ SYM_FUNC_START(crc_t10dif_pcl)
# Final CRC value (x^16 * M(x)) mod G(x) is in low 16 bits of xmm0.

pextrw $0, %xmm0, %eax
- ret
+ RET

.align 16
.Lless_than_256_bytes:
diff --git a/arch/x86/crypto/des3_ede-asm_64.S b/arch/x86/crypto/des3_ede-asm_64.S
index fac0fdc3f25d..f4c760f4cade 100644
--- a/arch/x86/crypto/des3_ede-asm_64.S
+++ b/arch/x86/crypto/des3_ede-asm_64.S
@@ -243,7 +243,7 @@ SYM_FUNC_START(des3_ede_x86_64_crypt_blk)
popq %r12;
popq %rbx;

- ret;
+ RET;
SYM_FUNC_END(des3_ede_x86_64_crypt_blk)

/***********************************************************************
@@ -528,7 +528,7 @@ SYM_FUNC_START(des3_ede_x86_64_crypt_blk_3way)
popq %r12;
popq %rbx;

- ret;
+ RET;
SYM_FUNC_END(des3_ede_x86_64_crypt_blk_3way)

.section .rodata, "a", @progbits
diff --git a/arch/x86/crypto/ghash-clmulni-intel_asm.S b/arch/x86/crypto/ghash-clmulni-intel_asm.S
index 99ac25e18e09..2bf871899920 100644
--- a/arch/x86/crypto/ghash-clmulni-intel_asm.S
+++ b/arch/x86/crypto/ghash-clmulni-intel_asm.S
@@ -85,7 +85,7 @@ SYM_FUNC_START_LOCAL(__clmul_gf128mul_ble)
psrlq $1, T2
pxor T2, T1
pxor T1, DATA
- ret
+ RET
SYM_FUNC_END(__clmul_gf128mul_ble)

/* void clmul_ghash_mul(char *dst, const u128 *shash) */
@@ -99,7 +99,7 @@ SYM_FUNC_START(clmul_ghash_mul)
pshufb BSWAP, DATA
movups DATA, (%rdi)
FRAME_END
- ret
+ RET
SYM_FUNC_END(clmul_ghash_mul)

/*
@@ -128,5 +128,5 @@ SYM_FUNC_START(clmul_ghash_update)
movups DATA, (%rdi)
.Lupdate_just_ret:
FRAME_END
- ret
+ RET
SYM_FUNC_END(clmul_ghash_update)
diff --git a/arch/x86/crypto/nh-avx2-x86_64.S b/arch/x86/crypto/nh-avx2-x86_64.S
index b22c7b936272..6a0b15e7196a 100644
--- a/arch/x86/crypto/nh-avx2-x86_64.S
+++ b/arch/x86/crypto/nh-avx2-x86_64.S
@@ -153,5 +153,5 @@ SYM_FUNC_START(nh_avx2)
vpaddq T1, T0, T0
vpaddq T4, T0, T0
vmovdqu T0, (HASH)
- ret
+ RET
SYM_FUNC_END(nh_avx2)
diff --git a/arch/x86/crypto/nh-sse2-x86_64.S b/arch/x86/crypto/nh-sse2-x86_64.S
index d7ae22dd6683..34c567bbcb4f 100644
--- a/arch/x86/crypto/nh-sse2-x86_64.S
+++ b/arch/x86/crypto/nh-sse2-x86_64.S
@@ -119,5 +119,5 @@ SYM_FUNC_START(nh_sse2)
paddq PASS2_SUMS, T1
movdqu T0, 0x00(HASH)
movdqu T1, 0x10(HASH)
- ret
+ RET
SYM_FUNC_END(nh_sse2)
diff --git a/arch/x86/crypto/poly1305-x86_64-cryptogams.pl b/arch/x86/crypto/poly1305-x86_64-cryptogams.pl
index 7d568012cc15..58eaec958c86 100644
--- a/arch/x86/crypto/poly1305-x86_64-cryptogams.pl
+++ b/arch/x86/crypto/poly1305-x86_64-cryptogams.pl
@@ -297,7 +297,7 @@ ___
$code.=<<___;
mov \$1,%eax
.Lno_key:
- ret
+ RET
___
&end_function("poly1305_init_x86_64");

@@ -373,7 +373,7 @@ $code.=<<___;
.cfi_adjust_cfa_offset -48
.Lno_data:
.Lblocks_epilogue:
- ret
+ RET
.cfi_endproc
___
&end_function("poly1305_blocks_x86_64");
@@ -399,7 +399,7 @@ $code.=<<___;
mov %rax,0($mac) # write result
mov %rcx,8($mac)

- ret
+ RET
___
&end_function("poly1305_emit_x86_64");
if ($avx) {
@@ -429,7 +429,7 @@ ___
&poly1305_iteration();
$code.=<<___;
pop $ctx
- ret
+ RET
.size __poly1305_block,.-__poly1305_block

.type __poly1305_init_avx,\@abi-omnipotent
@@ -594,7 +594,7 @@ __poly1305_init_avx:

lea -48-64($ctx),$ctx # size [de-]optimization
pop %rbp
- ret
+ RET
.size __poly1305_init_avx,.-__poly1305_init_avx
___

@@ -747,7 +747,7 @@ $code.=<<___;
.cfi_restore %rbp
.Lno_data_avx:
.Lblocks_avx_epilogue:
- ret
+ RET
.cfi_endproc

.align 32
@@ -1452,7 +1452,7 @@ $code.=<<___ if (!$win64);
___
$code.=<<___;
vzeroupper
- ret
+ RET
.cfi_endproc
___
&end_function("poly1305_blocks_avx");
@@ -1508,7 +1508,7 @@ $code.=<<___;
mov %rax,0($mac) # write result
mov %rcx,8($mac)

- ret
+ RET
___
&end_function("poly1305_emit_avx");

@@ -1675,7 +1675,7 @@ $code.=<<___;
.cfi_restore %rbp
.Lno_data_avx2$suffix:
.Lblocks_avx2_epilogue$suffix:
- ret
+ RET
.cfi_endproc

.align 32
@@ -2201,7 +2201,7 @@ $code.=<<___ if (!$win64);
___
$code.=<<___;
vzeroupper
- ret
+ RET
.cfi_endproc
___
if($avx > 2 && $avx512) {
@@ -2792,7 +2792,7 @@ $code.=<<___ if (!$win64);
.cfi_def_cfa_register %rsp
___
$code.=<<___;
- ret
+ RET
.cfi_endproc
___

@@ -2893,7 +2893,7 @@ $code.=<<___ if ($flavour =~ /elf32/);
___
$code.=<<___;
mov \$1,%eax
- ret
+ RET
.size poly1305_init_base2_44,.-poly1305_init_base2_44
___
{
@@ -3010,7 +3010,7 @@ poly1305_blocks_vpmadd52:
jnz .Lblocks_vpmadd52_4x

.Lno_data_vpmadd52:
- ret
+ RET
.size poly1305_blocks_vpmadd52,.-poly1305_blocks_vpmadd52
___
}
@@ -3451,7 +3451,7 @@ poly1305_blocks_vpmadd52_4x:
vzeroall

.Lno_data_vpmadd52_4x:
- ret
+ RET
.size poly1305_blocks_vpmadd52_4x,.-poly1305_blocks_vpmadd52_4x
___
}
@@ -3824,7 +3824,7 @@ $code.=<<___;
vzeroall

.Lno_data_vpmadd52_8x:
- ret
+ RET
.size poly1305_blocks_vpmadd52_8x,.-poly1305_blocks_vpmadd52_8x
___
}
@@ -3861,7 +3861,7 @@ poly1305_emit_base2_44:
mov %rax,0($mac) # write result
mov %rcx,8($mac)

- ret
+ RET
.size poly1305_emit_base2_44,.-poly1305_emit_base2_44
___
} } }
@@ -3916,7 +3916,7 @@ xor128_encrypt_n_pad:

.Ldone_enc:
mov $otp,%rax
- ret
+ RET
.size xor128_encrypt_n_pad,.-xor128_encrypt_n_pad

.globl xor128_decrypt_n_pad
@@ -3967,7 +3967,7 @@ xor128_decrypt_n_pad:

.Ldone_dec:
mov $otp,%rax
- ret
+ RET
.size xor128_decrypt_n_pad,.-xor128_decrypt_n_pad
___
}
@@ -4109,7 +4109,7 @@ avx_handler:
pop %rbx
pop %rdi
pop %rsi
- ret
+ RET
.size avx_handler,.-avx_handler

.section .pdata
diff --git a/arch/x86/crypto/serpent-avx-x86_64-asm_64.S b/arch/x86/crypto/serpent-avx-x86_64-asm_64.S
index ba9e4c1e7f5c..c985bc15304b 100644
--- a/arch/x86/crypto/serpent-avx-x86_64-asm_64.S
+++ b/arch/x86/crypto/serpent-avx-x86_64-asm_64.S
@@ -605,7 +605,7 @@ SYM_FUNC_START_LOCAL(__serpent_enc_blk8_avx)
write_blocks(RA1, RB1, RC1, RD1, RK0, RK1, RK2);
write_blocks(RA2, RB2, RC2, RD2, RK0, RK1, RK2);

- ret;
+ RET;
SYM_FUNC_END(__serpent_enc_blk8_avx)

.align 8
@@ -659,7 +659,7 @@ SYM_FUNC_START_LOCAL(__serpent_dec_blk8_avx)
write_blocks(RC1, RD1, RB1, RE1, RK0, RK1, RK2);
write_blocks(RC2, RD2, RB2, RE2, RK0, RK1, RK2);

- ret;
+ RET;
SYM_FUNC_END(__serpent_dec_blk8_avx)

SYM_FUNC_START(serpent_ecb_enc_8way_avx)
@@ -677,7 +677,7 @@ SYM_FUNC_START(serpent_ecb_enc_8way_avx)
store_8way(%rsi, RA1, RB1, RC1, RD1, RA2, RB2, RC2, RD2);

FRAME_END
- ret;
+ RET;
SYM_FUNC_END(serpent_ecb_enc_8way_avx)

SYM_FUNC_START(serpent_ecb_dec_8way_avx)
@@ -695,7 +695,7 @@ SYM_FUNC_START(serpent_ecb_dec_8way_avx)
store_8way(%rsi, RC1, RD1, RB1, RE1, RC2, RD2, RB2, RE2);

FRAME_END
- ret;
+ RET;
SYM_FUNC_END(serpent_ecb_dec_8way_avx)

SYM_FUNC_START(serpent_cbc_dec_8way_avx)
@@ -713,7 +713,7 @@ SYM_FUNC_START(serpent_cbc_dec_8way_avx)
store_cbc_8way(%rdx, %rsi, RC1, RD1, RB1, RE1, RC2, RD2, RB2, RE2);

FRAME_END
- ret;
+ RET;
SYM_FUNC_END(serpent_cbc_dec_8way_avx)

SYM_FUNC_START(serpent_ctr_8way_avx)
@@ -733,7 +733,7 @@ SYM_FUNC_START(serpent_ctr_8way_avx)
store_ctr_8way(%rdx, %rsi, RA1, RB1, RC1, RD1, RA2, RB2, RC2, RD2);

FRAME_END
- ret;
+ RET;
SYM_FUNC_END(serpent_ctr_8way_avx)

SYM_FUNC_START(serpent_xts_enc_8way_avx)
@@ -755,7 +755,7 @@ SYM_FUNC_START(serpent_xts_enc_8way_avx)
store_xts_8way(%rsi, RA1, RB1, RC1, RD1, RA2, RB2, RC2, RD2);

FRAME_END
- ret;
+ RET;
SYM_FUNC_END(serpent_xts_enc_8way_avx)

SYM_FUNC_START(serpent_xts_dec_8way_avx)
@@ -777,5 +777,5 @@ SYM_FUNC_START(serpent_xts_dec_8way_avx)
store_xts_8way(%rsi, RC1, RD1, RB1, RE1, RC2, RD2, RB2, RE2);

FRAME_END
- ret;
+ RET;
SYM_FUNC_END(serpent_xts_dec_8way_avx)
diff --git a/arch/x86/crypto/serpent-avx2-asm_64.S b/arch/x86/crypto/serpent-avx2-asm_64.S
index c9648aeae705..ca18948964f4 100644
--- a/arch/x86/crypto/serpent-avx2-asm_64.S
+++ b/arch/x86/crypto/serpent-avx2-asm_64.S
@@ -611,7 +611,7 @@ SYM_FUNC_START_LOCAL(__serpent_enc_blk16)
write_blocks(RA1, RB1, RC1, RD1, RK0, RK1, RK2);
write_blocks(RA2, RB2, RC2, RD2, RK0, RK1, RK2);

- ret;
+ RET;
SYM_FUNC_END(__serpent_enc_blk16)

.align 8
@@ -665,7 +665,7 @@ SYM_FUNC_START_LOCAL(__serpent_dec_blk16)
write_blocks(RC1, RD1, RB1, RE1, RK0, RK1, RK2);
write_blocks(RC2, RD2, RB2, RE2, RK0, RK1, RK2);

- ret;
+ RET;
SYM_FUNC_END(__serpent_dec_blk16)

SYM_FUNC_START(serpent_ecb_enc_16way)
@@ -687,7 +687,7 @@ SYM_FUNC_START(serpent_ecb_enc_16way)
vzeroupper;

FRAME_END
- ret;
+ RET;
SYM_FUNC_END(serpent_ecb_enc_16way)

SYM_FUNC_START(serpent_ecb_dec_16way)
@@ -709,7 +709,7 @@ SYM_FUNC_START(serpent_ecb_dec_16way)
vzeroupper;

FRAME_END
- ret;
+ RET;
SYM_FUNC_END(serpent_ecb_dec_16way)

SYM_FUNC_START(serpent_cbc_dec_16way)
@@ -732,7 +732,7 @@ SYM_FUNC_START(serpent_cbc_dec_16way)
vzeroupper;

FRAME_END
- ret;
+ RET;
SYM_FUNC_END(serpent_cbc_dec_16way)

SYM_FUNC_START(serpent_ctr_16way)
@@ -757,7 +757,7 @@ SYM_FUNC_START(serpent_ctr_16way)
vzeroupper;

FRAME_END
- ret;
+ RET;
SYM_FUNC_END(serpent_ctr_16way)

SYM_FUNC_START(serpent_xts_enc_16way)
@@ -783,7 +783,7 @@ SYM_FUNC_START(serpent_xts_enc_16way)
vzeroupper;

FRAME_END
- ret;
+ RET;
SYM_FUNC_END(serpent_xts_enc_16way)

SYM_FUNC_START(serpent_xts_dec_16way)
@@ -809,5 +809,5 @@ SYM_FUNC_START(serpent_xts_dec_16way)
vzeroupper;

FRAME_END
- ret;
+ RET;
SYM_FUNC_END(serpent_xts_dec_16way)
diff --git a/arch/x86/crypto/serpent-sse2-i586-asm_32.S b/arch/x86/crypto/serpent-sse2-i586-asm_32.S
index 6379b99cb722..8ccb03ad7cef 100644
--- a/arch/x86/crypto/serpent-sse2-i586-asm_32.S
+++ b/arch/x86/crypto/serpent-sse2-i586-asm_32.S
@@ -553,12 +553,12 @@ SYM_FUNC_START(__serpent_enc_blk_4way)

write_blocks(%eax, RA, RB, RC, RD, RT0, RT1, RE);

- ret;
+ RET;

.L__enc_xor4:
xor_blocks(%eax, RA, RB, RC, RD, RT0, RT1, RE);

- ret;
+ RET;
SYM_FUNC_END(__serpent_enc_blk_4way)

SYM_FUNC_START(serpent_dec_blk_4way)
@@ -612,5 +612,5 @@ SYM_FUNC_START(serpent_dec_blk_4way)
movl arg_dst(%esp), %eax;
write_blocks(%eax, RC, RD, RB, RE, RT0, RT1, RA);

- ret;
+ RET;
SYM_FUNC_END(serpent_dec_blk_4way)
diff --git a/arch/x86/crypto/serpent-sse2-x86_64-asm_64.S b/arch/x86/crypto/serpent-sse2-x86_64-asm_64.S
index efb6dc17dc90..e0998a011d1d 100644
--- a/arch/x86/crypto/serpent-sse2-x86_64-asm_64.S
+++ b/arch/x86/crypto/serpent-sse2-x86_64-asm_64.S
@@ -675,13 +675,13 @@ SYM_FUNC_START(__serpent_enc_blk_8way)
write_blocks(%rsi, RA1, RB1, RC1, RD1, RK0, RK1, RK2);
write_blocks(%rax, RA2, RB2, RC2, RD2, RK0, RK1, RK2);

- ret;
+ RET;

.L__enc_xor8:
xor_blocks(%rsi, RA1, RB1, RC1, RD1, RK0, RK1, RK2);
xor_blocks(%rax, RA2, RB2, RC2, RD2, RK0, RK1, RK2);

- ret;
+ RET;
SYM_FUNC_END(__serpent_enc_blk_8way)

SYM_FUNC_START(serpent_dec_blk_8way)
@@ -735,5 +735,5 @@ SYM_FUNC_START(serpent_dec_blk_8way)
write_blocks(%rsi, RC1, RD1, RB1, RE1, RK0, RK1, RK2);
write_blocks(%rax, RC2, RD2, RB2, RE2, RK0, RK1, RK2);

- ret;
+ RET;
SYM_FUNC_END(serpent_dec_blk_8way)
diff --git a/arch/x86/crypto/sha1_avx2_x86_64_asm.S b/arch/x86/crypto/sha1_avx2_x86_64_asm.S
index 1e594d60afa5..6fa622652bfc 100644
--- a/arch/x86/crypto/sha1_avx2_x86_64_asm.S
+++ b/arch/x86/crypto/sha1_avx2_x86_64_asm.S
@@ -674,7 +674,7 @@ _loop3:
pop %r12
pop %rbx

- ret
+ RET

SYM_FUNC_END(\name)
.endm
diff --git a/arch/x86/crypto/sha1_ni_asm.S b/arch/x86/crypto/sha1_ni_asm.S
index 11efe3a45a1f..b59f3ca62837 100644
--- a/arch/x86/crypto/sha1_ni_asm.S
+++ b/arch/x86/crypto/sha1_ni_asm.S
@@ -290,7 +290,7 @@ SYM_FUNC_START(sha1_ni_transform)
.Ldone_hash:
mov RSPSAVE, %rsp

- ret
+ RET
SYM_FUNC_END(sha1_ni_transform)

.section .rodata.cst16.PSHUFFLE_BYTE_FLIP_MASK, "aM", @progbits, 16
diff --git a/arch/x86/crypto/sha1_ssse3_asm.S b/arch/x86/crypto/sha1_ssse3_asm.S
index d25668d2a1e9..263f916362e0 100644
--- a/arch/x86/crypto/sha1_ssse3_asm.S
+++ b/arch/x86/crypto/sha1_ssse3_asm.S
@@ -99,7 +99,7 @@
pop %rbp
pop %r12
pop %rbx
- ret
+ RET

SYM_FUNC_END(\name)
.endm
diff --git a/arch/x86/crypto/sha256-avx-asm.S b/arch/x86/crypto/sha256-avx-asm.S
index 4739cd31b9db..3baa1ec39097 100644
--- a/arch/x86/crypto/sha256-avx-asm.S
+++ b/arch/x86/crypto/sha256-avx-asm.S
@@ -458,7 +458,7 @@ done_hash:
popq %r13
popq %r12
popq %rbx
- ret
+ RET
SYM_FUNC_END(sha256_transform_avx)

.section .rodata.cst256.K256, "aM", @progbits, 256
diff --git a/arch/x86/crypto/sha256-avx2-asm.S b/arch/x86/crypto/sha256-avx2-asm.S
index 11ff60c29c8b..3439aaf4295d 100644
--- a/arch/x86/crypto/sha256-avx2-asm.S
+++ b/arch/x86/crypto/sha256-avx2-asm.S
@@ -711,7 +711,7 @@ done_hash:
popq %r13
popq %r12
popq %rbx
- ret
+ RET
SYM_FUNC_END(sha256_transform_rorx)

.section .rodata.cst512.K256, "aM", @progbits, 512
diff --git a/arch/x86/crypto/sha256-ssse3-asm.S b/arch/x86/crypto/sha256-ssse3-asm.S
index ddfa863b4ee3..c4a5db612c32 100644
--- a/arch/x86/crypto/sha256-ssse3-asm.S
+++ b/arch/x86/crypto/sha256-ssse3-asm.S
@@ -472,7 +472,7 @@ done_hash:
popq %r12
popq %rbx

- ret
+ RET
SYM_FUNC_END(sha256_transform_ssse3)

.section .rodata.cst256.K256, "aM", @progbits, 256
diff --git a/arch/x86/crypto/sha256_ni_asm.S b/arch/x86/crypto/sha256_ni_asm.S
index 7abade04a3a3..94d50dd27cb5 100644
--- a/arch/x86/crypto/sha256_ni_asm.S
+++ b/arch/x86/crypto/sha256_ni_asm.S
@@ -326,7 +326,7 @@ SYM_FUNC_START(sha256_ni_transform)

.Ldone_hash:

- ret
+ RET
SYM_FUNC_END(sha256_ni_transform)

.section .rodata.cst256.K256, "aM", @progbits, 256
diff --git a/arch/x86/crypto/sha512-avx-asm.S b/arch/x86/crypto/sha512-avx-asm.S
index 63470fd6ae32..34fc71c3524e 100644
--- a/arch/x86/crypto/sha512-avx-asm.S
+++ b/arch/x86/crypto/sha512-avx-asm.S
@@ -364,7 +364,7 @@ updateblock:
mov frame_RSPSAVE(%rsp), %rsp

nowork:
- ret
+ RET
SYM_FUNC_END(sha512_transform_avx)

########################################################################
diff --git a/arch/x86/crypto/sha512-avx2-asm.S b/arch/x86/crypto/sha512-avx2-asm.S
index 3a44bdcfd583..399fa74ab3d3 100644
--- a/arch/x86/crypto/sha512-avx2-asm.S
+++ b/arch/x86/crypto/sha512-avx2-asm.S
@@ -681,7 +681,7 @@ done_hash:

# Restore Stack Pointer
mov frame_RSPSAVE(%rsp), %rsp
- ret
+ RET
SYM_FUNC_END(sha512_transform_rorx)

########################################################################
diff --git a/arch/x86/crypto/sha512-ssse3-asm.S b/arch/x86/crypto/sha512-ssse3-asm.S
index 7946a1bee85b..e9b460a54503 100644
--- a/arch/x86/crypto/sha512-ssse3-asm.S
+++ b/arch/x86/crypto/sha512-ssse3-asm.S
@@ -366,7 +366,7 @@ updateblock:
mov frame_RSPSAVE(%rsp), %rsp

nowork:
- ret
+ RET
SYM_FUNC_END(sha512_transform_ssse3)

########################################################################
diff --git a/arch/x86/crypto/twofish-avx-x86_64-asm_64.S b/arch/x86/crypto/twofish-avx-x86_64-asm_64.S
index a5151393bb2f..c3707a71ef72 100644
--- a/arch/x86/crypto/twofish-avx-x86_64-asm_64.S
+++ b/arch/x86/crypto/twofish-avx-x86_64-asm_64.S
@@ -272,7 +272,7 @@ SYM_FUNC_START_LOCAL(__twofish_enc_blk8)
outunpack_blocks(RC1, RD1, RA1, RB1, RK1, RX0, RY0, RK2);
outunpack_blocks(RC2, RD2, RA2, RB2, RK1, RX0, RY0, RK2);

- ret;
+ RET;
SYM_FUNC_END(__twofish_enc_blk8)

.align 8
@@ -312,7 +312,7 @@ SYM_FUNC_START_LOCAL(__twofish_dec_blk8)
outunpack_blocks(RA1, RB1, RC1, RD1, RK1, RX0, RY0, RK2);
outunpack_blocks(RA2, RB2, RC2, RD2, RK1, RX0, RY0, RK2);

- ret;
+ RET;
SYM_FUNC_END(__twofish_dec_blk8)

SYM_FUNC_START(twofish_ecb_enc_8way)
@@ -332,7 +332,7 @@ SYM_FUNC_START(twofish_ecb_enc_8way)
store_8way(%r11, RC1, RD1, RA1, RB1, RC2, RD2, RA2, RB2);

FRAME_END
- ret;
+ RET;
SYM_FUNC_END(twofish_ecb_enc_8way)

SYM_FUNC_START(twofish_ecb_dec_8way)
@@ -352,7 +352,7 @@ SYM_FUNC_START(twofish_ecb_dec_8way)
store_8way(%r11, RA1, RB1, RC1, RD1, RA2, RB2, RC2, RD2);

FRAME_END
- ret;
+ RET;
SYM_FUNC_END(twofish_ecb_dec_8way)

SYM_FUNC_START(twofish_cbc_dec_8way)
@@ -377,7 +377,7 @@ SYM_FUNC_START(twofish_cbc_dec_8way)
popq %r12;

FRAME_END
- ret;
+ RET;
SYM_FUNC_END(twofish_cbc_dec_8way)

SYM_FUNC_START(twofish_ctr_8way)
@@ -404,7 +404,7 @@ SYM_FUNC_START(twofish_ctr_8way)
popq %r12;

FRAME_END
- ret;
+ RET;
SYM_FUNC_END(twofish_ctr_8way)

SYM_FUNC_START(twofish_xts_enc_8way)
@@ -428,7 +428,7 @@ SYM_FUNC_START(twofish_xts_enc_8way)
store_xts_8way(%r11, RC1, RD1, RA1, RB1, RC2, RD2, RA2, RB2);

FRAME_END
- ret;
+ RET;
SYM_FUNC_END(twofish_xts_enc_8way)

SYM_FUNC_START(twofish_xts_dec_8way)
@@ -452,5 +452,5 @@ SYM_FUNC_START(twofish_xts_dec_8way)
store_xts_8way(%r11, RA1, RB1, RC1, RD1, RA2, RB2, RC2, RD2);

FRAME_END
- ret;
+ RET;
SYM_FUNC_END(twofish_xts_dec_8way)
diff --git a/arch/x86/crypto/twofish-i586-asm_32.S b/arch/x86/crypto/twofish-i586-asm_32.S
index a6f09e4f2e46..3abcad661884 100644
--- a/arch/x86/crypto/twofish-i586-asm_32.S
+++ b/arch/x86/crypto/twofish-i586-asm_32.S
@@ -260,7 +260,7 @@ SYM_FUNC_START(twofish_enc_blk)
pop %ebx
pop %ebp
mov $1, %eax
- ret
+ RET
SYM_FUNC_END(twofish_enc_blk)

SYM_FUNC_START(twofish_dec_blk)
@@ -317,5 +317,5 @@ SYM_FUNC_START(twofish_dec_blk)
pop %ebx
pop %ebp
mov $1, %eax
- ret
+ RET
SYM_FUNC_END(twofish_dec_blk)
diff --git a/arch/x86/crypto/twofish-x86_64-asm_64-3way.S b/arch/x86/crypto/twofish-x86_64-asm_64-3way.S
index fc23552afe37..b12d916f08d6 100644
--- a/arch/x86/crypto/twofish-x86_64-asm_64-3way.S
+++ b/arch/x86/crypto/twofish-x86_64-asm_64-3way.S
@@ -258,7 +258,7 @@ SYM_FUNC_START(__twofish_enc_blk_3way)
popq %rbx;
popq %r12;
popq %r13;
- ret;
+ RET;

.L__enc_xor3:
outunpack_enc3(xor);
@@ -266,7 +266,7 @@ SYM_FUNC_START(__twofish_enc_blk_3way)
popq %rbx;
popq %r12;
popq %r13;
- ret;
+ RET;
SYM_FUNC_END(__twofish_enc_blk_3way)

SYM_FUNC_START(twofish_dec_blk_3way)
@@ -301,5 +301,5 @@ SYM_FUNC_START(twofish_dec_blk_3way)
popq %rbx;
popq %r12;
popq %r13;
- ret;
+ RET;
SYM_FUNC_END(twofish_dec_blk_3way)
diff --git a/arch/x86/crypto/twofish-x86_64-asm_64.S b/arch/x86/crypto/twofish-x86_64-asm_64.S
index d2e56232494a..775af290cd19 100644
--- a/arch/x86/crypto/twofish-x86_64-asm_64.S
+++ b/arch/x86/crypto/twofish-x86_64-asm_64.S
@@ -252,7 +252,7 @@ SYM_FUNC_START(twofish_enc_blk)

popq R1
movl $1,%eax
- ret
+ RET
SYM_FUNC_END(twofish_enc_blk)

SYM_FUNC_START(twofish_dec_blk)
@@ -304,5 +304,5 @@ SYM_FUNC_START(twofish_dec_blk)

popq R1
movl $1,%eax
- ret
+ RET
SYM_FUNC_END(twofish_dec_blk)
diff --git a/arch/x86/entry/Makefile b/arch/x86/entry/Makefile
index 08bf95dbc911..58533752efab 100644
--- a/arch/x86/entry/Makefile
+++ b/arch/x86/entry/Makefile
@@ -21,7 +21,7 @@ CFLAGS_syscall_64.o += $(call cc-option,-Wno-override-init,)
CFLAGS_syscall_32.o += $(call cc-option,-Wno-override-init,)
CFLAGS_syscall_x32.o += $(call cc-option,-Wno-override-init,)

-obj-y := entry_$(BITS).o thunk_$(BITS).o syscall_$(BITS).o
+obj-y := entry.o entry_$(BITS).o thunk_$(BITS).o syscall_$(BITS).o
obj-y += common.o

obj-y += vdso/
diff --git a/arch/x86/entry/calling.h b/arch/x86/entry/calling.h
index 07a9331d55e7..a4b357e5bbfe 100644
--- a/arch/x86/entry/calling.h
+++ b/arch/x86/entry/calling.h
@@ -6,6 +6,8 @@
#include <asm/percpu.h>
#include <asm/asm-offsets.h>
#include <asm/processor-flags.h>
+#include <asm/msr.h>
+#include <asm/nospec-branch.h>

/*

@@ -146,27 +148,19 @@ For 32-bit we have the following conventions - kernel is built with

.endm

-.macro POP_REGS pop_rdi=1 skip_r11rcx=0
+.macro POP_REGS pop_rdi=1
popq %r15
popq %r14
popq %r13
popq %r12
popq %rbp
popq %rbx
- .if \skip_r11rcx
- popq %rsi
- .else
popq %r11
- .endif
popq %r10
popq %r9
popq %r8
popq %rax
- .if \skip_r11rcx
- popq %rsi
- .else
popq %rcx
- .endif
popq %rdx
popq %rsi
.if \pop_rdi
@@ -316,6 +310,66 @@ For 32-bit we have the following conventions - kernel is built with

#endif

+/*
+ * IBRS kernel mitigation for Spectre_v2.
+ *
+ * Assumes full context is established (PUSH_REGS, CR3 and GS) and it clobbers
+ * the regs it uses (AX, CX, DX). Must be called before the first RET
+ * instruction (NOTE! UNTRAIN_RET includes a RET instruction)
+ *
+ * The optional argument is used to save/restore the current value,
+ * which is used on the paranoid paths.
+ *
+ * Assumes x86_spec_ctrl_{base,current} to have SPEC_CTRL_IBRS set.
+ */
+.macro IBRS_ENTER save_reg
+#ifdef CONFIG_CPU_IBRS_ENTRY
+ ALTERNATIVE "jmp .Lend_\@", "", X86_FEATURE_KERNEL_IBRS
+ movl $MSR_IA32_SPEC_CTRL, %ecx
+
+.ifnb \save_reg
+ rdmsr
+ shl $32, %rdx
+ or %rdx, %rax
+ mov %rax, \save_reg
+ test $SPEC_CTRL_IBRS, %eax
+ jz .Ldo_wrmsr_\@
+ lfence
+ jmp .Lend_\@
+.Ldo_wrmsr_\@:
+.endif
+
+ movq PER_CPU_VAR(x86_spec_ctrl_current), %rdx
+ movl %edx, %eax
+ shr $32, %rdx
+ wrmsr
+.Lend_\@:
+#endif
+.endm
+
+/*
+ * Similar to IBRS_ENTER, requires KERNEL GS,CR3 and clobbers (AX, CX, DX)
+ * regs. Must be called after the last RET.
+ */
+.macro IBRS_EXIT save_reg
+#ifdef CONFIG_CPU_IBRS_ENTRY
+ ALTERNATIVE "jmp .Lend_\@", "", X86_FEATURE_KERNEL_IBRS
+ movl $MSR_IA32_SPEC_CTRL, %ecx
+
+.ifnb \save_reg
+ mov \save_reg, %rdx
+.else
+ movq PER_CPU_VAR(x86_spec_ctrl_current), %rdx
+ andl $(~SPEC_CTRL_IBRS), %edx
+.endif
+
+ movl %edx, %eax
+ shr $32, %rdx
+ wrmsr
+.Lend_\@:
+#endif
+.endm
+
/*
* Mitigate Spectre v1 for conditional swapgs code paths.
*
diff --git a/arch/x86/entry/entry.S b/arch/x86/entry/entry.S
new file mode 100644
index 000000000000..bfb7bcb362bc
--- /dev/null
+++ b/arch/x86/entry/entry.S
@@ -0,0 +1,22 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Common place for both 32- and 64-bit entry routines.
+ */
+
+#include <linux/linkage.h>
+#include <asm/export.h>
+#include <asm/msr-index.h>
+
+.pushsection .noinstr.text, "ax"
+
+SYM_FUNC_START(entry_ibpb)
+ movl $MSR_IA32_PRED_CMD, %ecx
+ movl $PRED_CMD_IBPB, %eax
+ xorl %edx, %edx
+ wrmsr
+ RET
+SYM_FUNC_END(entry_ibpb)
+/* For KVM */
+EXPORT_SYMBOL_GPL(entry_ibpb);
+
+.popsection
diff --git a/arch/x86/entry/entry_32.S b/arch/x86/entry/entry_32.S
index df8c017e6161..8fcd6a42b3a1 100644
--- a/arch/x86/entry/entry_32.S
+++ b/arch/x86/entry/entry_32.S
@@ -40,7 +40,7 @@
#include <asm/processor-flags.h>
#include <asm/irq_vectors.h>
#include <asm/cpufeatures.h>
-#include <asm/alternative-asm.h>
+#include <asm/alternative.h>
#include <asm/asm.h>
#include <asm/smap.h>
#include <asm/frame.h>
@@ -782,7 +782,6 @@ SYM_CODE_START(__switch_to_asm)
movl %ebx, PER_CPU_VAR(stack_canary)+stack_canary_offset
#endif

-#ifdef CONFIG_RETPOLINE
/*
* When switching from a shallower to a deeper call stack
* the RSB may either underflow or use entries populated
@@ -791,7 +790,6 @@ SYM_CODE_START(__switch_to_asm)
* speculative execution to prevent attack.
*/
FILL_RETURN_BUFFER %ebx, RSB_CLEAR_LOOPS, X86_FEATURE_RSB_CTXSW
-#endif

/* Restore flags or the incoming task to restore AC state. */
popfl
@@ -821,7 +819,7 @@ SYM_FUNC_START(schedule_tail_wrapper)
popl %eax

FRAME_END
- ret
+ RET
SYM_FUNC_END(schedule_tail_wrapper)
.popsection

diff --git a/arch/x86/entry/entry_64.S b/arch/x86/entry/entry_64.S
index 2f2d52729e17..559c82b83475 100644
--- a/arch/x86/entry/entry_64.S
+++ b/arch/x86/entry/entry_64.S
@@ -93,7 +93,7 @@ SYM_CODE_END(native_usergs_sysret64)
*/

SYM_CODE_START(entry_SYSCALL_64)
- UNWIND_HINT_EMPTY
+ UNWIND_HINT_ENTRY

swapgs
/* tss.sp2 is scratch space. */
@@ -117,6 +117,11 @@ SYM_INNER_LABEL(entry_SYSCALL_64_after_hwframe, SYM_L_GLOBAL)
/* IRQs are off. */
movq %rax, %rdi
movq %rsp, %rsi
+
+ /* clobbers %rax, make sure it is after saving the syscall nr */
+ IBRS_ENTER
+ UNTRAIN_RET
+
call do_syscall_64 /* returns with IRQs disabled */

/*
@@ -191,8 +196,8 @@ SYM_INNER_LABEL(entry_SYSCALL_64_after_hwframe, SYM_L_GLOBAL)
* perf profiles. Nothing jumps here.
*/
syscall_return_via_sysret:
- /* rcx and r11 are already restored (see code above) */
- POP_REGS pop_rdi=0 skip_r11rcx=1
+ IBRS_EXIT
+ POP_REGS pop_rdi=0

/*
* Now all regs are restored except RSP and RDI.
@@ -244,7 +249,6 @@ SYM_FUNC_START(__switch_to_asm)
movq %rbx, PER_CPU_VAR(fixed_percpu_data) + stack_canary_offset
#endif

-#ifdef CONFIG_RETPOLINE
/*
* When switching from a shallower to a deeper call stack
* the RSB may either underflow or use entries populated
@@ -253,7 +257,6 @@ SYM_FUNC_START(__switch_to_asm)
* speculative execution to prevent attack.
*/
FILL_RETURN_BUFFER %r12, RSB_CLEAR_LOOPS, X86_FEATURE_RSB_CTXSW
-#endif

/* restore callee-saved registers */
popq %r15
@@ -569,6 +572,7 @@ __irqentry_text_end:

SYM_CODE_START_LOCAL(common_interrupt_return)
SYM_INNER_LABEL(swapgs_restore_regs_and_return_to_usermode, SYM_L_GLOBAL)
+ IBRS_EXIT
#ifdef CONFIG_DEBUG_ENTRY
/* Assert that pt_regs indicates user mode. */
testb $3, CS(%rsp)
@@ -676,6 +680,7 @@ native_irq_return_ldt:
pushq %rdi /* Stash user RDI */
swapgs /* to kernel GS */
SWITCH_TO_KERNEL_CR3 scratch_reg=%rdi /* to kernel CR3 */
+ UNTRAIN_RET

movq PER_CPU_VAR(espfix_waddr), %rdi
movq %rax, (0*8)(%rdi) /* user RAX */
@@ -740,7 +745,7 @@ SYM_FUNC_START(asm_load_gs_index)
2: ALTERNATIVE "", "mfence", X86_BUG_SWAPGS_FENCE
swapgs
FRAME_END
- ret
+ RET
SYM_FUNC_END(asm_load_gs_index)
EXPORT_SYMBOL(asm_load_gs_index)

@@ -799,7 +804,7 @@ SYM_INNER_LABEL(asm_call_irq_on_stack, SYM_L_GLOBAL)

/* Restore the previous stack pointer from RBP. */
leaveq
- ret
+ RET
SYM_FUNC_END(asm_call_on_stack)

#ifdef CONFIG_XEN_PV
@@ -888,6 +893,9 @@ SYM_CODE_END(xen_failsafe_callback)
* 1 -> no SWAPGS on exit
*
* Y GSBASE value at entry, must be restored in paranoid_exit
+ *
+ * R14 - old CR3
+ * R15 - old SPEC_CTRL
*/
SYM_CODE_START_LOCAL(paranoid_entry)
UNWIND_HINT_FUNC
@@ -932,7 +940,7 @@ SYM_CODE_START_LOCAL(paranoid_entry)
* is needed here.
*/
SAVE_AND_SET_GSBASE scratch_reg=%rax save_reg=%rbx
- ret
+ jmp .Lparanoid_gsbase_done

.Lparanoid_entry_checkgs:
/* EBX = 1 -> kernel GSBASE active, no restore required */
@@ -951,9 +959,17 @@ SYM_CODE_START_LOCAL(paranoid_entry)
xorl %ebx, %ebx
swapgs
.Lparanoid_kernel_gsbase:
-
FENCE_SWAPGS_KERNEL_ENTRY
- ret
+.Lparanoid_gsbase_done:
+
+ /*
+ * Once we have CR3 and %GS setup save and set SPEC_CTRL. Just like
+ * CR3 above, keep the old value in a callee saved register.
+ */
+ IBRS_ENTER save_reg=%r15
+ UNTRAIN_RET
+
+ RET
SYM_CODE_END(paranoid_entry)

/*
@@ -974,9 +990,19 @@ SYM_CODE_END(paranoid_entry)
* 1 -> no SWAPGS on exit
*
* Y User space GSBASE, must be restored unconditionally
+ *
+ * R14 - old CR3
+ * R15 - old SPEC_CTRL
*/
SYM_CODE_START_LOCAL(paranoid_exit)
UNWIND_HINT_REGS
+
+ /*
+ * Must restore IBRS state before both CR3 and %GS since we need access
+ * to the per-CPU x86_spec_ctrl_shadow variable.
+ */
+ IBRS_EXIT save_reg=%r15
+
/*
* The order of operations is important. RESTORE_CR3 requires
* kernel GSBASE.
@@ -1023,8 +1049,11 @@ SYM_CODE_START_LOCAL(error_entry)
FENCE_SWAPGS_USER_ENTRY
/* We have user CR3. Change to kernel CR3. */
SWITCH_TO_KERNEL_CR3 scratch_reg=%rax
+ IBRS_ENTER
+ UNTRAIN_RET

.Lerror_entry_from_usermode_after_swapgs:
+
/* Put us onto the real thread stack. */
popq %r12 /* save return addr in %12 */
movq %rsp, %rdi /* arg0 = pt_regs pointer */
@@ -1032,7 +1061,7 @@ SYM_CODE_START_LOCAL(error_entry)
movq %rax, %rsp /* switch stack */
ENCODE_FRAME_POINTER
pushq %r12
- ret
+ RET

/*
* There are two places in the kernel that can potentially fault with
@@ -1063,7 +1092,8 @@ SYM_CODE_START_LOCAL(error_entry)
*/
.Lerror_entry_done_lfence:
FENCE_SWAPGS_KERNEL_ENTRY
- ret
+ ANNOTATE_UNRET_END
+ RET

.Lbstep_iret:
/* Fix truncated RIP */
@@ -1078,6 +1108,8 @@ SYM_CODE_START_LOCAL(error_entry)
SWAPGS
FENCE_SWAPGS_USER_ENTRY
SWITCH_TO_KERNEL_CR3 scratch_reg=%rax
+ IBRS_ENTER
+ UNTRAIN_RET

/*
* Pretend that the exception came from user mode: set up pt_regs
@@ -1182,6 +1214,9 @@ SYM_CODE_START(asm_exc_nmi)
PUSH_AND_CLEAR_REGS rdx=(%rdx)
ENCODE_FRAME_POINTER

+ IBRS_ENTER
+ UNTRAIN_RET
+
/*
* At this point we no longer need to worry about stack damage
* due to nesting -- we're on the normal thread stack and we're
@@ -1404,6 +1439,9 @@ end_repeat_nmi:
movq $-1, %rsi
call exc_nmi

+ /* Always restore stashed SPEC_CTRL value (see paranoid_entry) */
+ IBRS_EXIT save_reg=%r15
+
/* Always restore stashed CR3 value (see paranoid_entry) */
RESTORE_CR3 scratch_reg=%r15 save_reg=%r14

diff --git a/arch/x86/entry/entry_64_compat.S b/arch/x86/entry/entry_64_compat.S
index 0051cf5c792d..4d637a965efb 100644
--- a/arch/x86/entry/entry_64_compat.S
+++ b/arch/x86/entry/entry_64_compat.S
@@ -4,7 +4,6 @@
*
* Copyright 2000-2002 Andi Kleen, SuSE Labs.
*/
-#include "calling.h"
#include <asm/asm-offsets.h>
#include <asm/current.h>
#include <asm/errno.h>
@@ -14,9 +13,12 @@
#include <asm/irqflags.h>
#include <asm/asm.h>
#include <asm/smap.h>
+#include <asm/nospec-branch.h>
#include <linux/linkage.h>
#include <linux/err.h>

+#include "calling.h"
+
.section .entry.text, "ax"

/*
@@ -47,7 +49,7 @@
* 0(%ebp) arg6
*/
SYM_CODE_START(entry_SYSENTER_compat)
- UNWIND_HINT_EMPTY
+ UNWIND_HINT_ENTRY
/* Interrupts are off on entry. */
SWAPGS

@@ -112,6 +114,9 @@ SYM_INNER_LABEL(entry_SYSENTER_compat_after_hwframe, SYM_L_GLOBAL)

cld

+ IBRS_ENTER
+ UNTRAIN_RET
+
/*
* SYSENTER doesn't filter flags, so we need to clear NT and AC
* ourselves. To save a few cycles, we can check whether
@@ -197,7 +202,7 @@ SYM_CODE_END(entry_SYSENTER_compat)
* 0(%esp) arg6
*/
SYM_CODE_START(entry_SYSCALL_compat)
- UNWIND_HINT_EMPTY
+ UNWIND_HINT_ENTRY
/* Interrupts are off on entry. */
swapgs

@@ -252,6 +257,9 @@ SYM_INNER_LABEL(entry_SYSCALL_compat_after_hwframe, SYM_L_GLOBAL)

UNWIND_HINT_REGS

+ IBRS_ENTER
+ UNTRAIN_RET
+
movq %rsp, %rdi
call do_fast_syscall_32
/* XEN PV guests always use IRET path */
@@ -266,6 +274,8 @@ sysret32_from_system_call:
*/
STACKLEAK_ERASE

+ IBRS_EXIT
+
movq RBX(%rsp), %rbx /* pt_regs->rbx */
movq RBP(%rsp), %rbp /* pt_regs->rbp */
movq EFLAGS(%rsp), %r11 /* pt_regs->flags (in r11) */
@@ -339,7 +349,7 @@ SYM_CODE_END(entry_SYSCALL_compat)
* ebp arg6
*/
SYM_CODE_START(entry_INT80_compat)
- UNWIND_HINT_EMPTY
+ UNWIND_HINT_ENTRY
/*
* Interrupts are off on entry.
*/
@@ -409,6 +419,9 @@ SYM_CODE_START(entry_INT80_compat)

cld

+ IBRS_ENTER
+ UNTRAIN_RET
+
movq %rsp, %rdi
call do_int80_syscall_32
jmp swapgs_restore_regs_and_return_to_usermode
diff --git a/arch/x86/entry/thunk_32.S b/arch/x86/entry/thunk_32.S
index f1f96d4d8cd6..7591bab060f7 100644
--- a/arch/x86/entry/thunk_32.S
+++ b/arch/x86/entry/thunk_32.S
@@ -24,7 +24,7 @@ SYM_CODE_START_NOALIGN(\name)
popl %edx
popl %ecx
popl %eax
- ret
+ RET
_ASM_NOKPROBE(\name)
SYM_CODE_END(\name)
.endm
diff --git a/arch/x86/entry/thunk_64.S b/arch/x86/entry/thunk_64.S
index c9a9fbf1655f..1b5044ad8cd0 100644
--- a/arch/x86/entry/thunk_64.S
+++ b/arch/x86/entry/thunk_64.S
@@ -55,7 +55,7 @@ SYM_CODE_START_LOCAL_NOALIGN(__thunk_restore)
popq %rsi
popq %rdi
popq %rbp
- ret
+ RET
_ASM_NOKPROBE(__thunk_restore)
SYM_CODE_END(__thunk_restore)
#endif
diff --git a/arch/x86/entry/vdso/Makefile b/arch/x86/entry/vdso/Makefile
index 21243747965d..f181220f1b5d 100644
--- a/arch/x86/entry/vdso/Makefile
+++ b/arch/x86/entry/vdso/Makefile
@@ -91,6 +91,7 @@ endif
endif

$(vobjs): KBUILD_CFLAGS := $(filter-out $(GCC_PLUGINS_CFLAGS) $(RETPOLINE_CFLAGS),$(KBUILD_CFLAGS)) $(CFL)
+$(vobjs): KBUILD_AFLAGS += -DBUILD_VDSO

#
# vDSO code runs in userspace and -pg doesn't help with profiling anyway.
diff --git a/arch/x86/entry/vdso/vdso32/system_call.S b/arch/x86/entry/vdso/vdso32/system_call.S
index de1fff7188aa..c92a8fef2ed2 100644
--- a/arch/x86/entry/vdso/vdso32/system_call.S
+++ b/arch/x86/entry/vdso/vdso32/system_call.S
@@ -6,7 +6,7 @@
#include <linux/linkage.h>
#include <asm/dwarf2.h>
#include <asm/cpufeatures.h>
-#include <asm/alternative-asm.h>
+#include <asm/alternative.h>

.text
.globl __kernel_vsyscall
@@ -78,7 +78,7 @@ SYM_INNER_LABEL(int80_landing_pad, SYM_L_GLOBAL)
popl %ecx
CFI_RESTORE ecx
CFI_ADJUST_CFA_OFFSET -4
- ret
+ RET
CFI_ENDPROC

.size __kernel_vsyscall,.-__kernel_vsyscall
diff --git a/arch/x86/entry/vsyscall/vsyscall_emu_64.S b/arch/x86/entry/vsyscall/vsyscall_emu_64.S
index 2e203f3a25a7..ef2dd1827243 100644
--- a/arch/x86/entry/vsyscall/vsyscall_emu_64.S
+++ b/arch/x86/entry/vsyscall/vsyscall_emu_64.S
@@ -20,16 +20,19 @@ __vsyscall_page:
mov $__NR_gettimeofday, %rax
syscall
ret
+ int3

.balign 1024, 0xcc
mov $__NR_time, %rax
syscall
ret
+ int3

.balign 1024, 0xcc
mov $__NR_getcpu, %rax
syscall
ret
+ int3

.balign 4096, 0xcc

diff --git a/arch/x86/include/asm/GEN-for-each-reg.h b/arch/x86/include/asm/GEN-for-each-reg.h
index 1b07fb102c4e..07949102a08d 100644
--- a/arch/x86/include/asm/GEN-for-each-reg.h
+++ b/arch/x86/include/asm/GEN-for-each-reg.h
@@ -1,11 +1,16 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * These are in machine order; things rely on that.
+ */
#ifdef CONFIG_64BIT
GEN(rax)
-GEN(rbx)
GEN(rcx)
GEN(rdx)
+GEN(rbx)
+GEN(rsp)
+GEN(rbp)
GEN(rsi)
GEN(rdi)
-GEN(rbp)
GEN(r8)
GEN(r9)
GEN(r10)
@@ -16,10 +21,11 @@ GEN(r14)
GEN(r15)
#else
GEN(eax)
-GEN(ebx)
GEN(ecx)
GEN(edx)
+GEN(ebx)
+GEN(esp)
+GEN(ebp)
GEN(esi)
GEN(edi)
-GEN(ebp)
#endif
diff --git a/arch/x86/include/asm/alternative-asm.h b/arch/x86/include/asm/alternative-asm.h
deleted file mode 100644
index 464034db299f..000000000000
--- a/arch/x86/include/asm/alternative-asm.h
+++ /dev/null
@@ -1,114 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0 */
-#ifndef _ASM_X86_ALTERNATIVE_ASM_H
-#define _ASM_X86_ALTERNATIVE_ASM_H
-
-#ifdef __ASSEMBLY__
-
-#include <asm/asm.h>
-
-#ifdef CONFIG_SMP
- .macro LOCK_PREFIX
-672: lock
- .pushsection .smp_locks,"a"
- .balign 4
- .long 672b - .
- .popsection
- .endm
-#else
- .macro LOCK_PREFIX
- .endm
-#endif
-
-/*
- * objtool annotation to ignore the alternatives and only consider the original
- * instruction(s).
- */
-.macro ANNOTATE_IGNORE_ALTERNATIVE
- .Lannotate_\@:
- .pushsection .discard.ignore_alts
- .long .Lannotate_\@ - .
- .popsection
-.endm
-
-/*
- * Issue one struct alt_instr descriptor entry (need to put it into
- * the section .altinstructions, see below). This entry contains
- * enough information for the alternatives patching code to patch an
- * instruction. See apply_alternatives().
- */
-.macro altinstruction_entry orig alt feature orig_len alt_len pad_len
- .long \orig - .
- .long \alt - .
- .word \feature
- .byte \orig_len
- .byte \alt_len
- .byte \pad_len
-.endm
-
-/*
- * Define an alternative between two instructions. If @feature is
- * present, early code in apply_alternatives() replaces @oldinstr with
- * @newinstr. ".skip" directive takes care of proper instruction padding
- * in case @newinstr is longer than @oldinstr.
- */
-.macro ALTERNATIVE oldinstr, newinstr, feature
-140:
- \oldinstr
-141:
- .skip -(((144f-143f)-(141b-140b)) > 0) * ((144f-143f)-(141b-140b)),0x90
-142:
-
- .pushsection .altinstructions,"a"
- altinstruction_entry 140b,143f,\feature,142b-140b,144f-143f,142b-141b
- .popsection
-
- .pushsection .altinstr_replacement,"ax"
-143:
- \newinstr
-144:
- .popsection
-.endm
-
-#define old_len 141b-140b
-#define new_len1 144f-143f
-#define new_len2 145f-144f
-
-/*
- * gas compatible max based on the idea from:
- * http://graphics.stanford.edu/~seander/bithacks.html#IntegerMinOrMax
- *
- * The additional "-" is needed because gas uses a "true" value of -1.
- */
-#define alt_max_short(a, b) ((a) ^ (((a) ^ (b)) & -(-((a) < (b)))))
-
-
-/*
- * Same as ALTERNATIVE macro above but for two alternatives. If CPU
- * has @feature1, it replaces @oldinstr with @newinstr1. If CPU has
- * @feature2, it replaces @oldinstr with @feature2.
- */
-.macro ALTERNATIVE_2 oldinstr, newinstr1, feature1, newinstr2, feature2
-140:
- \oldinstr
-141:
- .skip -((alt_max_short(new_len1, new_len2) - (old_len)) > 0) * \
- (alt_max_short(new_len1, new_len2) - (old_len)),0x90
-142:
-
- .pushsection .altinstructions,"a"
- altinstruction_entry 140b,143f,\feature1,142b-140b,144f-143f,142b-141b
- altinstruction_entry 140b,144f,\feature2,142b-140b,145f-144f,142b-141b
- .popsection
-
- .pushsection .altinstr_replacement,"ax"
-143:
- \newinstr1
-144:
- \newinstr2
-145:
- .popsection
-.endm
-
-#endif /* __ASSEMBLY__ */
-
-#endif /* _ASM_X86_ALTERNATIVE_ASM_H */
diff --git a/arch/x86/include/asm/alternative.h b/arch/x86/include/asm/alternative.h
index 13adca37c99a..0e777b27972b 100644
--- a/arch/x86/include/asm/alternative.h
+++ b/arch/x86/include/asm/alternative.h
@@ -2,13 +2,17 @@
#ifndef _ASM_X86_ALTERNATIVE_H
#define _ASM_X86_ALTERNATIVE_H

-#ifndef __ASSEMBLY__
-
#include <linux/types.h>
-#include <linux/stddef.h>
#include <linux/stringify.h>
#include <asm/asm.h>

+#define ALTINSTR_FLAG_INV (1 << 15)
+#define ALT_NOT(feat) ((feat) | ALTINSTR_FLAG_INV)
+
+#ifndef __ASSEMBLY__
+
+#include <linux/stddef.h>
+
/*
* Alternative inline assembly for SMP.
*
@@ -61,7 +65,6 @@ struct alt_instr {
u16 cpuid; /* cpuid bit set for replacement */
u8 instrlen; /* length of original instruction */
u8 replacementlen; /* length of new instruction */
- u8 padlen; /* length of build-time padding */
} __packed;

/*
@@ -72,6 +75,8 @@ extern int alternatives_patched;

extern void alternative_instructions(void);
extern void apply_alternatives(struct alt_instr *start, struct alt_instr *end);
+extern void apply_retpolines(s32 *start, s32 *end);
+extern void apply_returns(s32 *start, s32 *end);

struct module;

@@ -100,7 +105,6 @@ static inline int alternatives_text_reserved(void *start, void *end)

#define alt_end_marker "663"
#define alt_slen "662b-661b"
-#define alt_pad_len alt_end_marker"b-662b"
#define alt_total_slen alt_end_marker"b-661b"
#define alt_rlen(num) e_replacement(num)"f-"b_replacement(num)"f"

@@ -147,8 +151,7 @@ static inline int alternatives_text_reserved(void *start, void *end)
" .long " b_replacement(num)"f - .\n" /* new instruction */ \
" .word " __stringify(feature) "\n" /* feature bit */ \
" .byte " alt_total_slen "\n" /* source len */ \
- " .byte " alt_rlen(num) "\n" /* replacement len */ \
- " .byte " alt_pad_len "\n" /* pad len */
+ " .byte " alt_rlen(num) "\n" /* replacement len */

#define ALTINSTR_REPLACEMENT(newinstr, feature, num) /* replacement */ \
"# ALT: replacement " #num "\n" \
@@ -175,6 +178,11 @@ static inline int alternatives_text_reserved(void *start, void *end)
ALTINSTR_REPLACEMENT(newinstr2, feature2, 2) \
".popsection\n"

+/* If @feature is set, patch in @newinstr_yes, otherwise @newinstr_no. */
+#define ALTERNATIVE_TERNARY(oldinstr, feature, newinstr_yes, newinstr_no) \
+ ALTERNATIVE_2(oldinstr, newinstr_no, X86_FEATURE_ALWAYS, \
+ newinstr_yes, feature)
+
#define ALTERNATIVE_3(oldinsn, newinsn1, feat1, newinsn2, feat2, newinsn3, feat3) \
OLDINSTR_3(oldinsn, 1, 2, 3) \
".pushsection .altinstructions,\"a\"\n" \
@@ -206,15 +214,15 @@ static inline int alternatives_text_reserved(void *start, void *end)
#define alternative_2(oldinstr, newinstr1, feature1, newinstr2, feature2) \
asm_inline volatile(ALTERNATIVE_2(oldinstr, newinstr1, feature1, newinstr2, feature2) ::: "memory")

+#define alternative_ternary(oldinstr, feature, newinstr_yes, newinstr_no) \
+ asm_inline volatile(ALTERNATIVE_TERNARY(oldinstr, feature, newinstr_yes, newinstr_no) ::: "memory")
+
/*
* Alternative inline assembly with input.
*
* Peculiarities:
* No memory clobber here.
* Argument numbers start with 1.
- * Best is to use constraints that are fixed size (like (%1) ... "r")
- * If you use variable sized constraints like "m" or "g" in the
- * replacement make sure to pad to the worst case length.
* Leaving an unused argument 0 to keep API compatibility.
*/
#define alternative_input(oldinstr, newinstr, feature, input...) \
@@ -271,6 +279,115 @@ static inline int alternatives_text_reserved(void *start, void *end)
*/
#define ASM_NO_INPUT_CLOBBER(clbr...) "i" (0) : clbr

+#else /* __ASSEMBLY__ */
+
+#ifdef CONFIG_SMP
+ .macro LOCK_PREFIX
+672: lock
+ .pushsection .smp_locks,"a"
+ .balign 4
+ .long 672b - .
+ .popsection
+ .endm
+#else
+ .macro LOCK_PREFIX
+ .endm
+#endif
+
+/*
+ * objtool annotation to ignore the alternatives and only consider the original
+ * instruction(s).
+ */
+.macro ANNOTATE_IGNORE_ALTERNATIVE
+ .Lannotate_\@:
+ .pushsection .discard.ignore_alts
+ .long .Lannotate_\@ - .
+ .popsection
+.endm
+
+/*
+ * Issue one struct alt_instr descriptor entry (need to put it into
+ * the section .altinstructions, see below). This entry contains
+ * enough information for the alternatives patching code to patch an
+ * instruction. See apply_alternatives().
+ */
+.macro altinstruction_entry orig alt feature orig_len alt_len
+ .long \orig - .
+ .long \alt - .
+ .word \feature
+ .byte \orig_len
+ .byte \alt_len
+.endm
+
+/*
+ * Define an alternative between two instructions. If @feature is
+ * present, early code in apply_alternatives() replaces @oldinstr with
+ * @newinstr. ".skip" directive takes care of proper instruction padding
+ * in case @newinstr is longer than @oldinstr.
+ */
+.macro ALTERNATIVE oldinstr, newinstr, feature
+140:
+ \oldinstr
+141:
+ .skip -(((144f-143f)-(141b-140b)) > 0) * ((144f-143f)-(141b-140b)),0x90
+142:
+
+ .pushsection .altinstructions,"a"
+ altinstruction_entry 140b,143f,\feature,142b-140b,144f-143f
+ .popsection
+
+ .pushsection .altinstr_replacement,"ax"
+143:
+ \newinstr
+144:
+ .popsection
+.endm
+
+#define old_len 141b-140b
+#define new_len1 144f-143f
+#define new_len2 145f-144f
+
+/*
+ * gas compatible max based on the idea from:
+ * http://graphics.stanford.edu/~seander/bithacks.html#IntegerMinOrMax
+ *
+ * The additional "-" is needed because gas uses a "true" value of -1.
+ */
+#define alt_max_short(a, b) ((a) ^ (((a) ^ (b)) & -(-((a) < (b)))))
+
+
+/*
+ * Same as ALTERNATIVE macro above but for two alternatives. If CPU
+ * has @feature1, it replaces @oldinstr with @newinstr1. If CPU has
+ * @feature2, it replaces @oldinstr with @feature2.
+ */
+.macro ALTERNATIVE_2 oldinstr, newinstr1, feature1, newinstr2, feature2
+140:
+ \oldinstr
+141:
+ .skip -((alt_max_short(new_len1, new_len2) - (old_len)) > 0) * \
+ (alt_max_short(new_len1, new_len2) - (old_len)),0x90
+142:
+
+ .pushsection .altinstructions,"a"
+ altinstruction_entry 140b,143f,\feature1,142b-140b,144f-143f
+ altinstruction_entry 140b,144f,\feature2,142b-140b,145f-144f
+ .popsection
+
+ .pushsection .altinstr_replacement,"ax"
+143:
+ \newinstr1
+144:
+ \newinstr2
+145:
+ .popsection
+.endm
+
+/* If @feature is set, patch in @newinstr_yes, otherwise @newinstr_no. */
+#define ALTERNATIVE_TERNARY(oldinstr, feature, newinstr_yes, newinstr_no) \
+ ALTERNATIVE_2 oldinstr, newinstr_no, X86_FEATURE_ALWAYS, \
+ newinstr_yes, feature
+
#endif /* __ASSEMBLY__ */

#endif /* _ASM_X86_ALTERNATIVE_H */
diff --git a/arch/x86/include/asm/asm-prototypes.h b/arch/x86/include/asm/asm-prototypes.h
index 51e2bf27cc9b..8f80de627c60 100644
--- a/arch/x86/include/asm/asm-prototypes.h
+++ b/arch/x86/include/asm/asm-prototypes.h
@@ -17,20 +17,3 @@
extern void cmpxchg8b_emu(void);
#endif

-#ifdef CONFIG_RETPOLINE
-
-#define DECL_INDIRECT_THUNK(reg) \
- extern asmlinkage void __x86_indirect_thunk_ ## reg (void);
-
-#define DECL_RETPOLINE(reg) \
- extern asmlinkage void __x86_retpoline_ ## reg (void);
-
-#undef GEN
-#define GEN(reg) DECL_INDIRECT_THUNK(reg)
-#include <asm/GEN-for-each-reg.h>
-
-#undef GEN
-#define GEN(reg) DECL_RETPOLINE(reg)
-#include <asm/GEN-for-each-reg.h>
-
-#endif /* CONFIG_RETPOLINE */
diff --git a/arch/x86/include/asm/cpufeature.h b/arch/x86/include/asm/cpufeature.h
index 619c1f80a2ab..f4cbc01c0bc4 100644
--- a/arch/x86/include/asm/cpufeature.h
+++ b/arch/x86/include/asm/cpufeature.h
@@ -8,6 +8,7 @@

#include <asm/asm.h>
#include <linux/bitops.h>
+#include <asm/alternative.h>

enum cpuid_leafs
{
@@ -172,39 +173,15 @@ extern void clear_cpu_cap(struct cpuinfo_x86 *c, unsigned int bit);
*/
static __always_inline bool _static_cpu_has(u16 bit)
{
- asm_volatile_goto("1: jmp 6f\n"
- "2:\n"
- ".skip -(((5f-4f) - (2b-1b)) > 0) * "
- "((5f-4f) - (2b-1b)),0x90\n"
- "3:\n"
- ".section .altinstructions,\"a\"\n"
- " .long 1b - .\n" /* src offset */
- " .long 4f - .\n" /* repl offset */
- " .word %P[always]\n" /* always replace */
- " .byte 3b - 1b\n" /* src len */
- " .byte 5f - 4f\n" /* repl len */
- " .byte 3b - 2b\n" /* pad len */
- ".previous\n"
- ".section .altinstr_replacement,\"ax\"\n"
- "4: jmp %l[t_no]\n"
- "5:\n"
- ".previous\n"
- ".section .altinstructions,\"a\"\n"
- " .long 1b - .\n" /* src offset */
- " .long 0\n" /* no replacement */
- " .word %P[feature]\n" /* feature bit */
- " .byte 3b - 1b\n" /* src len */
- " .byte 0\n" /* repl len */
- " .byte 0\n" /* pad len */
- ".previous\n"
- ".section .altinstr_aux,\"ax\"\n"
- "6:\n"
- " testb %[bitnum],%[cap_byte]\n"
- " jnz %l[t_yes]\n"
- " jmp %l[t_no]\n"
- ".previous\n"
+ asm_volatile_goto(
+ ALTERNATIVE_TERNARY("jmp 6f", %P[feature], "", "jmp %l[t_no]")
+ ".section .altinstr_aux,\"ax\"\n"
+ "6:\n"
+ " testb %[bitnum],%[cap_byte]\n"
+ " jnz %l[t_yes]\n"
+ " jmp %l[t_no]\n"
+ ".previous\n"
: : [feature] "i" (bit),
- [always] "i" (X86_FEATURE_ALWAYS),
[bitnum] "i" (1 << (bit & 7)),
[cap_byte] "m" (((const char *)boot_cpu_data.x86_capability)[bit >> 3])
: : t_yes, t_no);
diff --git a/arch/x86/include/asm/cpufeatures.h b/arch/x86/include/asm/cpufeatures.h
index f6a6ac0b3bcd..e077f4fe7c6d 100644
--- a/arch/x86/include/asm/cpufeatures.h
+++ b/arch/x86/include/asm/cpufeatures.h
@@ -203,8 +203,8 @@
#define X86_FEATURE_PROC_FEEDBACK ( 7*32+ 9) /* AMD ProcFeedbackInterface */
#define X86_FEATURE_SME ( 7*32+10) /* AMD Secure Memory Encryption */
#define X86_FEATURE_PTI ( 7*32+11) /* Kernel Page Table Isolation enabled */
-#define X86_FEATURE_RETPOLINE ( 7*32+12) /* "" Generic Retpoline mitigation for Spectre variant 2 */
-#define X86_FEATURE_RETPOLINE_LFENCE ( 7*32+13) /* "" Use LFENCE for Spectre variant 2 */
+#define X86_FEATURE_KERNEL_IBRS ( 7*32+12) /* "" Set/clear IBRS on kernel entry/exit */
+#define X86_FEATURE_RSB_VMEXIT ( 7*32+13) /* "" Fill RSB on VM-Exit */
#define X86_FEATURE_INTEL_PPIN ( 7*32+14) /* Intel Processor Inventory Number */
#define X86_FEATURE_CDP_L2 ( 7*32+15) /* Code and Data Prioritization L2 */
#define X86_FEATURE_MSR_SPEC_CTRL ( 7*32+16) /* "" MSR SPEC_CTRL is implemented */
@@ -290,6 +290,14 @@
#define X86_FEATURE_FENCE_SWAPGS_KERNEL (11*32+ 5) /* "" LFENCE in kernel entry SWAPGS path */
#define X86_FEATURE_SPLIT_LOCK_DETECT (11*32+ 6) /* #AC for split lock */
#define X86_FEATURE_PER_THREAD_MBA (11*32+ 7) /* "" Per-thread Memory Bandwidth Allocation */
+/* FREE! (11*32+ 8) */
+/* FREE! (11*32+ 9) */
+#define X86_FEATURE_ENTRY_IBPB (11*32+10) /* "" Issue an IBPB on kernel entry */
+#define X86_FEATURE_RRSBA_CTRL (11*32+11) /* "" RET prediction control */
+#define X86_FEATURE_RETPOLINE (11*32+12) /* "" Generic Retpoline mitigation for Spectre variant 2 */
+#define X86_FEATURE_RETPOLINE_LFENCE (11*32+13) /* "" Use LFENCE for Spectre variant 2 */
+#define X86_FEATURE_RETHUNK (11*32+14) /* "" Use REturn THUNK */
+#define X86_FEATURE_UNRET (11*32+15) /* "" AMD BTB untrain return */

/* Intel-defined CPU features, CPUID level 0x00000007:1 (EAX), word 12 */
#define X86_FEATURE_AVX512_BF16 (12*32+ 5) /* AVX512 BFLOAT16 instructions */
@@ -308,6 +316,7 @@
#define X86_FEATURE_AMD_SSBD (13*32+24) /* "" Speculative Store Bypass Disable */
#define X86_FEATURE_VIRT_SSBD (13*32+25) /* Virtualized Speculative Store Bypass Disable */
#define X86_FEATURE_AMD_SSB_NO (13*32+26) /* "" Speculative Store Bypass is fixed in hardware. */
+#define X86_FEATURE_BTC_NO (13*32+29) /* "" Not vulnerable to Branch Type Confusion */

/* Thermal and Power Management Leaf, CPUID level 0x00000006 (EAX), word 14 */
#define X86_FEATURE_DTHERM (14*32+ 0) /* Digital Thermal Sensor */
@@ -418,5 +427,6 @@
#define X86_BUG_ITLB_MULTIHIT X86_BUG(23) /* CPU may incur MCE during certain page attribute changes */
#define X86_BUG_SRBDS X86_BUG(24) /* CPU may leak RNG bits if not mitigated */
#define X86_BUG_MMIO_STALE_DATA X86_BUG(25) /* CPU is affected by Processor MMIO Stale Data vulnerabilities */
+#define X86_BUG_RETBLEED X86_BUG(26) /* CPU is affected by RETBleed */

#endif /* _ASM_X86_CPUFEATURES_H */
diff --git a/arch/x86/include/asm/disabled-features.h b/arch/x86/include/asm/disabled-features.h
index 09db5b8f1444..16c24915210d 100644
--- a/arch/x86/include/asm/disabled-features.h
+++ b/arch/x86/include/asm/disabled-features.h
@@ -56,6 +56,25 @@
# define DISABLE_PTI (1 << (X86_FEATURE_PTI & 31))
#endif

+#ifdef CONFIG_RETPOLINE
+# define DISABLE_RETPOLINE 0
+#else
+# define DISABLE_RETPOLINE ((1 << (X86_FEATURE_RETPOLINE & 31)) | \
+ (1 << (X86_FEATURE_RETPOLINE_LFENCE & 31)))
+#endif
+
+#ifdef CONFIG_RETHUNK
+# define DISABLE_RETHUNK 0
+#else
+# define DISABLE_RETHUNK (1 << (X86_FEATURE_RETHUNK & 31))
+#endif
+
+#ifdef CONFIG_CPU_UNRET_ENTRY
+# define DISABLE_UNRET 0
+#else
+# define DISABLE_UNRET (1 << (X86_FEATURE_UNRET & 31))
+#endif
+
/* Force disable because it's broken beyond repair */
#define DISABLE_ENQCMD (1 << (X86_FEATURE_ENQCMD & 31))

@@ -73,7 +92,7 @@
#define DISABLED_MASK8 0
#define DISABLED_MASK9 (DISABLE_SMAP)
#define DISABLED_MASK10 0
-#define DISABLED_MASK11 0
+#define DISABLED_MASK11 (DISABLE_RETPOLINE|DISABLE_RETHUNK|DISABLE_UNRET)
#define DISABLED_MASK12 0
#define DISABLED_MASK13 0
#define DISABLED_MASK14 0
diff --git a/arch/x86/include/asm/inat.h b/arch/x86/include/asm/inat.h
index 4cf2ad521f65..b56c5741581a 100644
--- a/arch/x86/include/asm/inat.h
+++ b/arch/x86/include/asm/inat.h
@@ -6,7 +6,7 @@
*
* Written by Masami Hiramatsu <mhiramat@redhat.com>
*/
-#include <asm/inat_types.h>
+#include <asm/inat_types.h> /* __ignore_sync_check__ */

/*
* Internal bits. Don't use bitmasks directly, because these bits are
diff --git a/arch/x86/include/asm/insn-eval.h b/arch/x86/include/asm/insn-eval.h
index c1438f9239e4..594ad2f57d23 100644
--- a/arch/x86/include/asm/insn-eval.h
+++ b/arch/x86/include/asm/insn-eval.h
@@ -26,7 +26,7 @@ int insn_fetch_from_user(struct pt_regs *regs,
unsigned char buf[MAX_INSN_SIZE]);
int insn_fetch_from_user_inatomic(struct pt_regs *regs,
unsigned char buf[MAX_INSN_SIZE]);
-bool insn_decode(struct insn *insn, struct pt_regs *regs,
- unsigned char buf[MAX_INSN_SIZE], int buf_size);
+bool insn_decode_from_regs(struct insn *insn, struct pt_regs *regs,
+ unsigned char buf[MAX_INSN_SIZE], int buf_size);

#endif /* _ASM_X86_INSN_EVAL_H */
diff --git a/arch/x86/include/asm/insn.h b/arch/x86/include/asm/insn.h
index a8c3d284fa46..0da37756917a 100644
--- a/arch/x86/include/asm/insn.h
+++ b/arch/x86/include/asm/insn.h
@@ -8,7 +8,7 @@
*/

/* insn_attr_t is defined in inat.h */
-#include <asm/inat.h>
+#include <asm/inat.h> /* __ignore_sync_check__ */

struct insn_field {
union {
@@ -87,13 +87,25 @@ struct insn {
#define X86_VEX_M_MAX 0x1f /* VEX3.M Maximum value */

extern void insn_init(struct insn *insn, const void *kaddr, int buf_len, int x86_64);
-extern void insn_get_prefixes(struct insn *insn);
-extern void insn_get_opcode(struct insn *insn);
-extern void insn_get_modrm(struct insn *insn);
-extern void insn_get_sib(struct insn *insn);
-extern void insn_get_displacement(struct insn *insn);
-extern void insn_get_immediate(struct insn *insn);
-extern void insn_get_length(struct insn *insn);
+extern int insn_get_prefixes(struct insn *insn);
+extern int insn_get_opcode(struct insn *insn);
+extern int insn_get_modrm(struct insn *insn);
+extern int insn_get_sib(struct insn *insn);
+extern int insn_get_displacement(struct insn *insn);
+extern int insn_get_immediate(struct insn *insn);
+extern int insn_get_length(struct insn *insn);
+
+enum insn_mode {
+ INSN_MODE_32,
+ INSN_MODE_64,
+ /* Mode is determined by the current kernel build. */
+ INSN_MODE_KERN,
+ INSN_NUM_MODES,
+};
+
+extern int insn_decode(struct insn *insn, const void *kaddr, int buf_len, enum insn_mode m);
+
+#define insn_decode_kernel(_insn, _ptr) insn_decode((_insn), (_ptr), MAX_INSN_SIZE, INSN_MODE_KERN)

/* Attribute will be determined after getting ModRM (for opcode groups) */
static inline void insn_get_attribute(struct insn *insn)
diff --git a/arch/x86/include/asm/linkage.h b/arch/x86/include/asm/linkage.h
index 365111789cc6..5000cf59bdf5 100644
--- a/arch/x86/include/asm/linkage.h
+++ b/arch/x86/include/asm/linkage.h
@@ -18,6 +18,28 @@
#define __ALIGN_STR __stringify(__ALIGN)
#endif

+#if defined(CONFIG_RETHUNK) && !defined(__DISABLE_EXPORTS) && !defined(BUILD_VDSO)
+#define RET jmp __x86_return_thunk
+#else /* CONFIG_RETPOLINE */
+#ifdef CONFIG_SLS
+#define RET ret; int3
+#else
+#define RET ret
+#endif
+#endif /* CONFIG_RETPOLINE */
+
+#else /* __ASSEMBLY__ */
+
+#if defined(CONFIG_RETHUNK) && !defined(__DISABLE_EXPORTS) && !defined(BUILD_VDSO)
+#define ASM_RET "jmp __x86_return_thunk\n\t"
+#else /* CONFIG_RETPOLINE */
+#ifdef CONFIG_SLS
+#define ASM_RET "ret; int3\n\t"
+#else
+#define ASM_RET "ret\n\t"
+#endif
+#endif /* CONFIG_RETPOLINE */
+
#endif /* __ASSEMBLY__ */

#endif /* _ASM_X86_LINKAGE_H */
diff --git a/arch/x86/include/asm/msr-index.h b/arch/x86/include/asm/msr-index.h
index 96973d197972..407de670cd60 100644
--- a/arch/x86/include/asm/msr-index.h
+++ b/arch/x86/include/asm/msr-index.h
@@ -51,6 +51,8 @@
#define SPEC_CTRL_STIBP BIT(SPEC_CTRL_STIBP_SHIFT) /* STIBP mask */
#define SPEC_CTRL_SSBD_SHIFT 2 /* Speculative Store Bypass Disable bit */
#define SPEC_CTRL_SSBD BIT(SPEC_CTRL_SSBD_SHIFT) /* Speculative Store Bypass Disable */
+#define SPEC_CTRL_RRSBA_DIS_S_SHIFT 6 /* Disable RRSBA behavior */
+#define SPEC_CTRL_RRSBA_DIS_S BIT(SPEC_CTRL_RRSBA_DIS_S_SHIFT)

#define MSR_IA32_PRED_CMD 0x00000049 /* Prediction Command */
#define PRED_CMD_IBPB BIT(0) /* Indirect Branch Prediction Barrier */
@@ -91,6 +93,7 @@
#define MSR_IA32_ARCH_CAPABILITIES 0x0000010a
#define ARCH_CAP_RDCL_NO BIT(0) /* Not susceptible to Meltdown */
#define ARCH_CAP_IBRS_ALL BIT(1) /* Enhanced IBRS support */
+#define ARCH_CAP_RSBA BIT(2) /* RET may use alternative branch predictors */
#define ARCH_CAP_SKIP_VMENTRY_L1DFLUSH BIT(3) /* Skip L1D flush on vmentry */
#define ARCH_CAP_SSB_NO BIT(4) /*
* Not susceptible to Speculative Store Bypass
@@ -138,6 +141,13 @@
* bit available to control VERW
* behavior.
*/
+#define ARCH_CAP_RRSBA BIT(19) /*
+ * Indicates RET may use predictors
+ * other than the RSB. With eIBRS
+ * enabled predictions in kernel mode
+ * are restricted to targets in
+ * kernel.
+ */

#define MSR_IA32_FLUSH_CMD 0x0000010b
#define L1D_FLUSH BIT(0) /*
@@ -507,6 +517,9 @@
/* Fam 17h MSRs */
#define MSR_F17H_IRPERF 0xc00000e9

+#define MSR_ZEN2_SPECTRAL_CHICKEN 0xc00110e3
+#define MSR_ZEN2_SPECTRAL_CHICKEN_BIT BIT_ULL(1)
+
/* Fam 16h MSRs */
#define MSR_F16H_L2I_PERF_CTL 0xc0010230
#define MSR_F16H_L2I_PERF_CTR 0xc0010231
diff --git a/arch/x86/include/asm/nospec-branch.h b/arch/x86/include/asm/nospec-branch.h
index e247151c3dcf..6f2adaf53f46 100644
--- a/arch/x86/include/asm/nospec-branch.h
+++ b/arch/x86/include/asm/nospec-branch.h
@@ -5,12 +5,15 @@

#include <linux/static_key.h>
#include <linux/objtool.h>
+#include <linux/linkage.h>

#include <asm/alternative.h>
-#include <asm/alternative-asm.h>
#include <asm/cpufeatures.h>
#include <asm/msr-index.h>
#include <asm/unwind_hints.h>
+#include <asm/percpu.h>
+
+#define RETPOLINE_THUNK_SIZE 32

/*
* Fill the CPU return stack buffer.
@@ -73,6 +76,23 @@
.popsection
.endm

+/*
+ * (ab)use RETPOLINE_SAFE on RET to annotate away 'bare' RET instructions
+ * vs RETBleed validation.
+ */
+#define ANNOTATE_UNRET_SAFE ANNOTATE_RETPOLINE_SAFE
+
+/*
+ * Abuse ANNOTATE_RETPOLINE_SAFE on a NOP to indicate UNRET_END, should
+ * eventually turn into it's own annotation.
+ */
+.macro ANNOTATE_UNRET_END
+#ifdef CONFIG_DEBUG_ENTRY
+ ANNOTATE_RETPOLINE_SAFE
+ nop
+#endif
+.endm
+
/*
* JMP_NOSPEC and CALL_NOSPEC macros can be used instead of a simple
* indirect jmp/call which may be susceptible to the Spectre variant 2
@@ -81,7 +101,7 @@
.macro JMP_NOSPEC reg:req
#ifdef CONFIG_RETPOLINE
ALTERNATIVE_2 __stringify(ANNOTATE_RETPOLINE_SAFE; jmp *%\reg), \
- __stringify(jmp __x86_retpoline_\reg), X86_FEATURE_RETPOLINE, \
+ __stringify(jmp __x86_indirect_thunk_\reg), X86_FEATURE_RETPOLINE, \
__stringify(lfence; ANNOTATE_RETPOLINE_SAFE; jmp *%\reg), X86_FEATURE_RETPOLINE_LFENCE
#else
jmp *%\reg
@@ -91,7 +111,7 @@
.macro CALL_NOSPEC reg:req
#ifdef CONFIG_RETPOLINE
ALTERNATIVE_2 __stringify(ANNOTATE_RETPOLINE_SAFE; call *%\reg), \
- __stringify(call __x86_retpoline_\reg), X86_FEATURE_RETPOLINE, \
+ __stringify(call __x86_indirect_thunk_\reg), X86_FEATURE_RETPOLINE, \
__stringify(lfence; ANNOTATE_RETPOLINE_SAFE; call *%\reg), X86_FEATURE_RETPOLINE_LFENCE
#else
call *%\reg
@@ -103,10 +123,34 @@
* monstrosity above, manually.
*/
.macro FILL_RETURN_BUFFER reg:req nr:req ftr:req
-#ifdef CONFIG_RETPOLINE
ALTERNATIVE "jmp .Lskip_rsb_\@", "", \ftr
__FILL_RETURN_BUFFER(\reg,\nr,%_ASM_SP)
.Lskip_rsb_\@:
+.endm
+
+#ifdef CONFIG_CPU_UNRET_ENTRY
+#define CALL_ZEN_UNTRAIN_RET "call zen_untrain_ret"
+#else
+#define CALL_ZEN_UNTRAIN_RET ""
+#endif
+
+/*
+ * Mitigate RETBleed for AMD/Hygon Zen uarch. Requires KERNEL CR3 because the
+ * return thunk isn't mapped into the userspace tables (then again, AMD
+ * typically has NO_MELTDOWN).
+ *
+ * While zen_untrain_ret() doesn't clobber anything but requires stack,
+ * entry_ibpb() will clobber AX, CX, DX.
+ *
+ * As such, this must be placed after every *SWITCH_TO_KERNEL_CR3 at a point
+ * where we have a stack but before any RET instruction.
+ */
+.macro UNTRAIN_RET
+#if defined(CONFIG_CPU_UNRET_ENTRY) || defined(CONFIG_CPU_IBPB_ENTRY)
+ ANNOTATE_UNRET_END
+ ALTERNATIVE_2 "", \
+ CALL_ZEN_UNTRAIN_RET, X86_FEATURE_UNRET, \
+ "call entry_ibpb", X86_FEATURE_ENTRY_IBPB
#endif
.endm

@@ -118,7 +162,21 @@
_ASM_PTR " 999b\n\t" \
".popsection\n\t"

+extern void __x86_return_thunk(void);
+extern void zen_untrain_ret(void);
+extern void entry_ibpb(void);
+
#ifdef CONFIG_RETPOLINE
+
+typedef u8 retpoline_thunk_t[RETPOLINE_THUNK_SIZE];
+
+#define GEN(reg) \
+ extern retpoline_thunk_t __x86_indirect_thunk_ ## reg;
+#include <asm/GEN-for-each-reg.h>
+#undef GEN
+
+extern retpoline_thunk_t __x86_indirect_thunk_array[];
+
#ifdef CONFIG_X86_64

/*
@@ -129,7 +187,7 @@
ALTERNATIVE_2( \
ANNOTATE_RETPOLINE_SAFE \
"call *%[thunk_target]\n", \
- "call __x86_retpoline_%V[thunk_target]\n", \
+ "call __x86_indirect_thunk_%V[thunk_target]\n", \
X86_FEATURE_RETPOLINE, \
"lfence;\n" \
ANNOTATE_RETPOLINE_SAFE \
@@ -181,6 +239,7 @@ enum spectre_v2_mitigation {
SPECTRE_V2_EIBRS,
SPECTRE_V2_EIBRS_RETPOLINE,
SPECTRE_V2_EIBRS_LFENCE,
+ SPECTRE_V2_IBRS,
};

/* The indirect branch speculation control variants */
@@ -223,6 +282,9 @@ static inline void indirect_branch_prediction_barrier(void)

/* The Intel SPEC CTRL MSR base value cache */
extern u64 x86_spec_ctrl_base;
+DECLARE_PER_CPU(u64, x86_spec_ctrl_current);
+extern void write_spec_ctrl_current(u64 val, bool force);
+extern u64 spec_ctrl_current(void);

/*
* With retpoline, we must use IBRS to restrict branch prediction
@@ -232,18 +294,16 @@ extern u64 x86_spec_ctrl_base;
*/
#define firmware_restrict_branch_speculation_start() \
do { \
- u64 val = x86_spec_ctrl_base | SPEC_CTRL_IBRS; \
- \
preempt_disable(); \
- alternative_msr_write(MSR_IA32_SPEC_CTRL, val, \
+ alternative_msr_write(MSR_IA32_SPEC_CTRL, \
+ spec_ctrl_current() | SPEC_CTRL_IBRS, \
X86_FEATURE_USE_IBRS_FW); \
} while (0)

#define firmware_restrict_branch_speculation_end() \
do { \
- u64 val = x86_spec_ctrl_base; \
- \
- alternative_msr_write(MSR_IA32_SPEC_CTRL, val, \
+ alternative_msr_write(MSR_IA32_SPEC_CTRL, \
+ spec_ctrl_current(), \
X86_FEATURE_USE_IBRS_FW); \
preempt_enable(); \
} while (0)
@@ -306,63 +366,4 @@ static inline void mds_idle_clear_cpu_buffers(void)

#endif /* __ASSEMBLY__ */

-/*
- * Below is used in the eBPF JIT compiler and emits the byte sequence
- * for the following assembly:
- *
- * With retpolines configured:
- *
- * callq do_rop
- * spec_trap:
- * pause
- * lfence
- * jmp spec_trap
- * do_rop:
- * mov %rcx,(%rsp) for x86_64
- * mov %edx,(%esp) for x86_32
- * retq
- *
- * Without retpolines configured:
- *
- * jmp *%rcx for x86_64
- * jmp *%edx for x86_32
- */
-#ifdef CONFIG_RETPOLINE
-# ifdef CONFIG_X86_64
-# define RETPOLINE_RCX_BPF_JIT_SIZE 17
-# define RETPOLINE_RCX_BPF_JIT() \
-do { \
- EMIT1_off32(0xE8, 7); /* callq do_rop */ \
- /* spec_trap: */ \
- EMIT2(0xF3, 0x90); /* pause */ \
- EMIT3(0x0F, 0xAE, 0xE8); /* lfence */ \
- EMIT2(0xEB, 0xF9); /* jmp spec_trap */ \
- /* do_rop: */ \
- EMIT4(0x48, 0x89, 0x0C, 0x24); /* mov %rcx,(%rsp) */ \
- EMIT1(0xC3); /* retq */ \
-} while (0)
-# else /* !CONFIG_X86_64 */
-# define RETPOLINE_EDX_BPF_JIT() \
-do { \
- EMIT1_off32(0xE8, 7); /* call do_rop */ \
- /* spec_trap: */ \
- EMIT2(0xF3, 0x90); /* pause */ \
- EMIT3(0x0F, 0xAE, 0xE8); /* lfence */ \
- EMIT2(0xEB, 0xF9); /* jmp spec_trap */ \
- /* do_rop: */ \
- EMIT3(0x89, 0x14, 0x24); /* mov %edx,(%esp) */ \
- EMIT1(0xC3); /* ret */ \
-} while (0)
-# endif
-#else /* !CONFIG_RETPOLINE */
-# ifdef CONFIG_X86_64
-# define RETPOLINE_RCX_BPF_JIT_SIZE 2
-# define RETPOLINE_RCX_BPF_JIT() \
- EMIT2(0xFF, 0xE1); /* jmp *%rcx */
-# else /* !CONFIG_X86_64 */
-# define RETPOLINE_EDX_BPF_JIT() \
- EMIT2(0xFF, 0xE2) /* jmp *%edx */
-# endif
-#endif
-
#endif /* _ASM_X86_NOSPEC_BRANCH_H_ */
diff --git a/arch/x86/include/asm/paravirt.h b/arch/x86/include/asm/paravirt.h
index 5647bcdba776..4a32b0d34376 100644
--- a/arch/x86/include/asm/paravirt.h
+++ b/arch/x86/include/asm/paravirt.h
@@ -630,7 +630,7 @@ bool __raw_callee_save___native_vcpu_is_preempted(long cpu);
"call " #func ";" \
PV_RESTORE_ALL_CALLER_REGS \
FRAME_END \
- "ret;" \
+ ASM_RET \
".size " PV_THUNK_NAME(func) ", .-" PV_THUNK_NAME(func) ";" \
".popsection")

diff --git a/arch/x86/include/asm/qspinlock_paravirt.h b/arch/x86/include/asm/qspinlock_paravirt.h
index 159622ee0674..1474cf96251d 100644
--- a/arch/x86/include/asm/qspinlock_paravirt.h
+++ b/arch/x86/include/asm/qspinlock_paravirt.h
@@ -48,7 +48,7 @@ asm (".pushsection .text;"
"jne .slowpath;"
"pop %rdx;"
FRAME_END
- "ret;"
+ ASM_RET
".slowpath: "
"push %rsi;"
"movzbl %al,%esi;"
@@ -56,7 +56,7 @@ asm (".pushsection .text;"
"pop %rsi;"
"pop %rdx;"
FRAME_END
- "ret;"
+ ASM_RET
".size " PV_UNLOCK ", .-" PV_UNLOCK ";"
".popsection");

diff --git a/arch/x86/include/asm/smap.h b/arch/x86/include/asm/smap.h
index 8b58d6975d5d..ea1d8eb644cb 100644
--- a/arch/x86/include/asm/smap.h
+++ b/arch/x86/include/asm/smap.h
@@ -11,6 +11,7 @@

#include <asm/nops.h>
#include <asm/cpufeatures.h>
+#include <asm/alternative.h>

/* "Raw" instruction opcodes */
#define __ASM_CLAC ".byte 0x0f,0x01,0xca"
@@ -18,8 +19,6 @@

#ifdef __ASSEMBLY__

-#include <asm/alternative-asm.h>
-
#ifdef CONFIG_X86_SMAP

#define ASM_CLAC \
@@ -37,8 +36,6 @@

#else /* __ASSEMBLY__ */

-#include <asm/alternative.h>
-
#ifdef CONFIG_X86_SMAP

static __always_inline void clac(void)
diff --git a/arch/x86/include/asm/static_call.h b/arch/x86/include/asm/static_call.h
index cbb67b6030f9..491aadfac611 100644
--- a/arch/x86/include/asm/static_call.h
+++ b/arch/x86/include/asm/static_call.h
@@ -21,6 +21,16 @@
* relative displacement across sections.
*/

+/*
+ * The trampoline is 8 bytes and of the general form:
+ *
+ * jmp.d32 \func
+ * ud1 %esp, %ecx
+ *
+ * That trailing #UD provides both a speculation stop and serves as a unique
+ * 3 byte signature identifying static call trampolines. Also see tramp_ud[]
+ * and __static_call_fixup().
+ */
#define __ARCH_DEFINE_STATIC_CALL_TRAMP(name, insns) \
asm(".pushsection .static_call.text, \"ax\" \n" \
".align 4 \n" \
@@ -34,8 +44,13 @@
#define ARCH_DEFINE_STATIC_CALL_TRAMP(name, func) \
__ARCH_DEFINE_STATIC_CALL_TRAMP(name, ".byte 0xe9; .long " #func " - (. + 4)")

+#ifdef CONFIG_RETHUNK
+#define ARCH_DEFINE_STATIC_CALL_NULL_TRAMP(name) \
+ __ARCH_DEFINE_STATIC_CALL_TRAMP(name, "jmp __x86_return_thunk")
+#else
#define ARCH_DEFINE_STATIC_CALL_NULL_TRAMP(name) \
- __ARCH_DEFINE_STATIC_CALL_TRAMP(name, "ret; nop; nop; nop; nop")
+ __ARCH_DEFINE_STATIC_CALL_TRAMP(name, "ret; int3; nop; nop; nop")
+#endif

#define ARCH_ADD_TRAMP_KEY(name) \
@@ -44,4 +59,6 @@
".long " STATIC_CALL_KEY_STR(name) " - . \n" \
".popsection \n")

+extern bool __static_call_fixup(void *tramp, u8 op, void *dest);
+
#endif /* _ASM_STATIC_CALL_H */
diff --git a/arch/x86/include/asm/unwind_hints.h b/arch/x86/include/asm/unwind_hints.h
index 664d4610d700..56664b31b6da 100644
--- a/arch/x86/include/asm/unwind_hints.h
+++ b/arch/x86/include/asm/unwind_hints.h
@@ -8,7 +8,11 @@
#ifdef __ASSEMBLY__

.macro UNWIND_HINT_EMPTY
- UNWIND_HINT sp_reg=ORC_REG_UNDEFINED type=UNWIND_HINT_TYPE_CALL end=1
+ UNWIND_HINT type=UNWIND_HINT_TYPE_CALL end=1
+.endm
+
+.macro UNWIND_HINT_ENTRY
+ UNWIND_HINT type=UNWIND_HINT_TYPE_ENTRY end=1
.endm

.macro UNWIND_HINT_REGS base=%rsp offset=0 indirect=0 extra=1 partial=0
@@ -48,17 +52,16 @@
UNWIND_HINT_REGS base=\base offset=\offset partial=1
.endm

-.macro UNWIND_HINT_FUNC sp_offset=8
- UNWIND_HINT sp_reg=ORC_REG_SP sp_offset=\sp_offset type=UNWIND_HINT_TYPE_CALL
+.macro UNWIND_HINT_FUNC
+ UNWIND_HINT sp_reg=ORC_REG_SP sp_offset=8 type=UNWIND_HINT_TYPE_FUNC
+.endm
+
+.macro UNWIND_HINT_SAVE
+ UNWIND_HINT type=UNWIND_HINT_TYPE_SAVE
.endm

-/*
- * RET_OFFSET: Used on instructions that terminate a function; mostly RETURN
- * and sibling calls. On these, sp_offset denotes the expected offset from
- * initial_func_cfi.
- */
-.macro UNWIND_HINT_RET_OFFSET sp_offset=8
- UNWIND_HINT sp_reg=ORC_REG_SP type=UNWIND_HINT_TYPE_RET_OFFSET sp_offset=\sp_offset
+.macro UNWIND_HINT_RESTORE
+ UNWIND_HINT type=UNWIND_HINT_TYPE_RESTORE
.endm

#endif /* __ASSEMBLY__ */
diff --git a/arch/x86/kernel/acpi/wakeup_32.S b/arch/x86/kernel/acpi/wakeup_32.S
index daf88f8143c5..cf69081073b5 100644
--- a/arch/x86/kernel/acpi/wakeup_32.S
+++ b/arch/x86/kernel/acpi/wakeup_32.S
@@ -60,7 +60,7 @@ save_registers:
popl saved_context_eflags

movl $ret_point, saved_eip
- ret
+ RET

restore_registers:
@@ -70,7 +70,7 @@ restore_registers:
movl saved_context_edi, %edi
pushl saved_context_eflags
popfl
- ret
+ RET

SYM_CODE_START(do_suspend_lowlevel)
call save_processor_state
@@ -86,7 +86,7 @@ SYM_CODE_START(do_suspend_lowlevel)
ret_point:
call restore_registers
call restore_processor_state
- ret
+ RET
SYM_CODE_END(do_suspend_lowlevel)

.data
diff --git a/arch/x86/kernel/alternative.c b/arch/x86/kernel/alternative.c
index 2400ad62f330..77eefa0b0f32 100644
--- a/arch/x86/kernel/alternative.c
+++ b/arch/x86/kernel/alternative.c
@@ -28,6 +28,7 @@
#include <asm/insn.h>
#include <asm/io.h>
#include <asm/fixmap.h>
+#include <asm/asm-prototypes.h>

int __read_mostly alternatives_patched;

@@ -268,6 +269,8 @@ static void __init_or_module add_nops(void *insns, unsigned int len)
}
}

+extern s32 __retpoline_sites[], __retpoline_sites_end[];
+extern s32 __return_sites[], __return_sites_end[];
extern struct alt_instr __alt_instructions[], __alt_instructions_end[];
extern s32 __smp_locks[], __smp_locks_end[];
void text_poke_early(void *addr, const void *opcode, size_t len);
@@ -338,25 +341,69 @@ recompute_jump(struct alt_instr *a, u8 *orig_insn, u8 *repl_insn, u8 *insn_buff)
}

/*
- * "noinline" to cause control flow change and thus invalidate I$ and
- * cause refetch after modification.
+ * optimize_nops_range() - Optimize a sequence of single byte NOPs (0x90)
+ *
+ * @instr: instruction byte stream
+ * @instrlen: length of the above
+ * @off: offset within @instr where the first NOP has been detected
+ *
+ * Return: number of NOPs found (and replaced).
*/
-static void __init_or_module noinline optimize_nops(struct alt_instr *a, u8 *instr)
+static __always_inline int optimize_nops_range(u8 *instr, u8 instrlen, int off)
{
unsigned long flags;
- int i;
+ int i = off, nnops;

- for (i = 0; i < a->padlen; i++) {
+ while (i < instrlen) {
if (instr[i] != 0x90)
- return;
+ break;
+
+ i++;
}

+ nnops = i - off;
+
+ if (nnops <= 1)
+ return nnops;
+
local_irq_save(flags);
- add_nops(instr + (a->instrlen - a->padlen), a->padlen);
+ add_nops(instr + off, nnops);
local_irq_restore(flags);

- DUMP_BYTES(instr, a->instrlen, "%px: [%d:%d) optimized NOPs: ",
- instr, a->instrlen - a->padlen, a->padlen);
+ DUMP_BYTES(instr, instrlen, "%px: [%d:%d) optimized NOPs: ", instr, off, i);
+
+ return nnops;
+}
+
+/*
+ * "noinline" to cause control flow change and thus invalidate I$ and
+ * cause refetch after modification.
+ */
+static void __init_or_module noinline optimize_nops(u8 *instr, size_t len)
+{
+ struct insn insn;
+ int i = 0;
+
+ /*
+ * Jump over the non-NOP insns and optimize single-byte NOPs into bigger
+ * ones.
+ */
+ for (;;) {
+ if (insn_decode_kernel(&insn, &instr[i]))
+ return;
+
+ /*
+ * See if this and any potentially following NOPs can be
+ * optimized.
+ */
+ if (insn.length == 1 && insn.opcode.bytes[0] == 0x90)
+ i += optimize_nops_range(instr, len, i);
+ else
+ i += insn.length;
+
+ if (i >= len)
+ return;
+ }
}

/*
@@ -388,23 +435,29 @@ void __init_or_module noinline apply_alternatives(struct alt_instr *start,
*/
for (a = start; a < end; a++) {
int insn_buff_sz = 0;
+ /* Mask away "NOT" flag bit for feature to test. */
+ u16 feature = a->cpuid & ~ALTINSTR_FLAG_INV;

instr = (u8 *)&a->instr_offset + a->instr_offset;
replacement = (u8 *)&a->repl_offset + a->repl_offset;
BUG_ON(a->instrlen > sizeof(insn_buff));
- BUG_ON(a->cpuid >= (NCAPINTS + NBUGINTS) * 32);
- if (!boot_cpu_has(a->cpuid)) {
- if (a->padlen > 1)
- optimize_nops(a, instr);
+ BUG_ON(feature >= (NCAPINTS + NBUGINTS) * 32);

- continue;
- }
+ /*
+ * Patch if either:
+ * - feature is present
+ * - feature not present but ALTINSTR_FLAG_INV is set to mean,
+ * patch if feature is *NOT* present.
+ */
+ if (!boot_cpu_has(feature) == !(a->cpuid & ALTINSTR_FLAG_INV))
+ goto next;

- DPRINTK("feat: %d*32+%d, old: (%pS (%px) len: %d), repl: (%px, len: %d), pad: %d",
- a->cpuid >> 5,
- a->cpuid & 0x1f,
+ DPRINTK("feat: %s%d*32+%d, old: (%pS (%px) len: %d), repl: (%px, len: %d)",
+ (a->cpuid & ALTINSTR_FLAG_INV) ? "!" : "",
+ feature >> 5,
+ feature & 0x1f,
instr, instr, a->instrlen,
- replacement, a->replacementlen, a->padlen);
+ replacement, a->replacementlen);

DUMP_BYTES(instr, a->instrlen, "%px: old_insn: ", instr);
DUMP_BYTES(replacement, a->replacementlen, "%px: rpl_insn: ", replacement);
@@ -428,16 +481,259 @@ void __init_or_module noinline apply_alternatives(struct alt_instr *start,
if (a->replacementlen && is_jmp(replacement[0]))
recompute_jump(a, instr, replacement, insn_buff);

- if (a->instrlen > a->replacementlen) {
- add_nops(insn_buff + a->replacementlen,
- a->instrlen - a->replacementlen);
- insn_buff_sz += a->instrlen - a->replacementlen;
- }
+ for (; insn_buff_sz < a->instrlen; insn_buff_sz++)
+ insn_buff[insn_buff_sz] = 0x90;
+
DUMP_BYTES(insn_buff, insn_buff_sz, "%px: final_insn: ", instr);

text_poke_early(instr, insn_buff, insn_buff_sz);
+
+next:
+ optimize_nops(instr, a->instrlen);
+ }
+}
+
+#if defined(CONFIG_RETPOLINE) && defined(CONFIG_STACK_VALIDATION)
+
+/*
+ * CALL/JMP *%\reg
+ */
+static int emit_indirect(int op, int reg, u8 *bytes)
+{
+ int i = 0;
+ u8 modrm;
+
+ switch (op) {
+ case CALL_INSN_OPCODE:
+ modrm = 0x10; /* Reg = 2; CALL r/m */
+ break;
+
+ case JMP32_INSN_OPCODE:
+ modrm = 0x20; /* Reg = 4; JMP r/m */
+ break;
+
+ default:
+ WARN_ON_ONCE(1);
+ return -1;
+ }
+
+ if (reg >= 8) {
+ bytes[i++] = 0x41; /* REX.B prefix */
+ reg -= 8;
+ }
+
+ modrm |= 0xc0; /* Mod = 3 */
+ modrm += reg;
+
+ bytes[i++] = 0xff; /* opcode */
+ bytes[i++] = modrm;
+
+ return i;
+}
+
+/*
+ * Rewrite the compiler generated retpoline thunk calls.
+ *
+ * For spectre_v2=off (!X86_FEATURE_RETPOLINE), rewrite them into immediate
+ * indirect instructions, avoiding the extra indirection.
+ *
+ * For example, convert:
+ *
+ * CALL __x86_indirect_thunk_\reg
+ *
+ * into:
+ *
+ * CALL *%\reg
+ *
+ * It also tries to inline spectre_v2=retpoline,amd when size permits.
+ */
+static int patch_retpoline(void *addr, struct insn *insn, u8 *bytes)
+{
+ retpoline_thunk_t *target;
+ int reg, ret, i = 0;
+ u8 op, cc;
+
+ target = addr + insn->length + insn->immediate.value;
+ reg = target - __x86_indirect_thunk_array;
+
+ if (WARN_ON_ONCE(reg & ~0xf))
+ return -1;
+
+ /* If anyone ever does: CALL/JMP *%rsp, we're in deep trouble. */
+ BUG_ON(reg == 4);
+
+ if (cpu_feature_enabled(X86_FEATURE_RETPOLINE) &&
+ !cpu_feature_enabled(X86_FEATURE_RETPOLINE_LFENCE))
+ return -1;
+
+ op = insn->opcode.bytes[0];
+
+ /*
+ * Convert:
+ *
+ * Jcc.d32 __x86_indirect_thunk_\reg
+ *
+ * into:
+ *
+ * Jncc.d8 1f
+ * [ LFENCE ]
+ * JMP *%\reg
+ * [ NOP ]
+ * 1:
+ */
+ /* Jcc.d32 second opcode byte is in the range: 0x80-0x8f */
+ if (op == 0x0f && (insn->opcode.bytes[1] & 0xf0) == 0x80) {
+ cc = insn->opcode.bytes[1] & 0xf;
+ cc ^= 1; /* invert condition */
+
+ bytes[i++] = 0x70 + cc; /* Jcc.d8 */
+ bytes[i++] = insn->length - 2; /* sizeof(Jcc.d8) == 2 */
+
+ /* Continue as if: JMP.d32 __x86_indirect_thunk_\reg */
+ op = JMP32_INSN_OPCODE;
+ }
+
+ /*
+ * For RETPOLINE_AMD: prepend the indirect CALL/JMP with an LFENCE.
+ */
+ if (cpu_feature_enabled(X86_FEATURE_RETPOLINE_LFENCE)) {
+ bytes[i++] = 0x0f;
+ bytes[i++] = 0xae;
+ bytes[i++] = 0xe8; /* LFENCE */
+ }
+
+ ret = emit_indirect(op, reg, bytes + i);
+ if (ret < 0)
+ return ret;
+ i += ret;
+
+ for (; i < insn->length;)
+ bytes[i++] = 0x90;
+
+ return i;
+}
+
+/*
+ * Generated by 'objtool --retpoline'.
+ */
+void __init_or_module noinline apply_retpolines(s32 *start, s32 *end)
+{
+ s32 *s;
+
+ for (s = start; s < end; s++) {
+ void *addr = (void *)s + *s;
+ struct insn insn;
+ int len, ret;
+ u8 bytes[16];
+ u8 op1, op2;
+
+ ret = insn_decode_kernel(&insn, addr);
+ if (WARN_ON_ONCE(ret < 0))
+ continue;
+
+ op1 = insn.opcode.bytes[0];
+ op2 = insn.opcode.bytes[1];
+
+ switch (op1) {
+ case CALL_INSN_OPCODE:
+ case JMP32_INSN_OPCODE:
+ break;
+
+ case 0x0f: /* escape */
+ if (op2 >= 0x80 && op2 <= 0x8f)
+ break;
+ fallthrough;
+ default:
+ WARN_ON_ONCE(1);
+ continue;
+ }
+
+ DPRINTK("retpoline at: %pS (%px) len: %d to: %pS",
+ addr, addr, insn.length,
+ addr + insn.length + insn.immediate.value);
+
+ len = patch_retpoline(addr, &insn, bytes);
+ if (len == insn.length) {
+ optimize_nops(bytes, len);
+ DUMP_BYTES(((u8*)addr), len, "%px: orig: ", addr);
+ DUMP_BYTES(((u8*)bytes), len, "%px: repl: ", addr);
+ text_poke_early(addr, bytes, len);
+ }
+ }
+}
+
+#ifdef CONFIG_RETHUNK
+/*
+ * Rewrite the compiler generated return thunk tail-calls.
+ *
+ * For example, convert:
+ *
+ * JMP __x86_return_thunk
+ *
+ * into:
+ *
+ * RET
+ */
+static int patch_return(void *addr, struct insn *insn, u8 *bytes)
+{
+ int i = 0;
+
+ if (cpu_feature_enabled(X86_FEATURE_RETHUNK))
+ return -1;
+
+ bytes[i++] = RET_INSN_OPCODE;
+
+ for (; i < insn->length;)
+ bytes[i++] = INT3_INSN_OPCODE;
+
+ return i;
+}
+
+void __init_or_module noinline apply_returns(s32 *start, s32 *end)
+{
+ s32 *s;
+
+ for (s = start; s < end; s++) {
+ void *dest = NULL, *addr = (void *)s + *s;
+ struct insn insn;
+ int len, ret;
+ u8 bytes[16];
+ u8 op;
+
+ ret = insn_decode_kernel(&insn, addr);
+ if (WARN_ON_ONCE(ret < 0))
+ continue;
+
+ op = insn.opcode.bytes[0];
+ if (op == JMP32_INSN_OPCODE)
+ dest = addr + insn.length + insn.immediate.value;
+
+ if (__static_call_fixup(addr, op, dest) ||
+ WARN_ON_ONCE(dest != &__x86_return_thunk))
+ continue;
+
+ DPRINTK("return thunk at: %pS (%px) len: %d to: %pS",
+ addr, addr, insn.length,
+ addr + insn.length + insn.immediate.value);
+
+ len = patch_return(addr, &insn, bytes);
+ if (len == insn.length) {
+ DUMP_BYTES(((u8*)addr), len, "%px: orig: ", addr);
+ DUMP_BYTES(((u8*)bytes), len, "%px: repl: ", addr);
+ text_poke_early(addr, bytes, len);
+ }
}
}
+#else
+void __init_or_module noinline apply_returns(s32 *start, s32 *end) { }
+#endif /* CONFIG_RETHUNK */
+
+#else /* !RETPOLINES || !CONFIG_STACK_VALIDATION */
+
+void __init_or_module noinline apply_retpolines(s32 *start, s32 *end) { }
+void __init_or_module noinline apply_returns(s32 *start, s32 *end) { }
+
+#endif /* CONFIG_RETPOLINE && CONFIG_STACK_VALIDATION */

#ifdef CONFIG_SMP
static void alternatives_smp_lock(const s32 *start, const s32 *end,
@@ -641,7 +937,7 @@ asm (
" .type int3_magic, @function\n"
"int3_magic:\n"
" movl $1, (%" _ASM_ARG1 ")\n"
-" ret\n"
+ ASM_RET
" .size int3_magic, .-int3_magic\n"
" .popsection\n"
);
@@ -723,6 +1019,13 @@ void __init alternative_instructions(void)
* patching.
*/

+ /*
+ * Rewrite the retpolines, must be done before alternatives since
+ * those can rewrite the retpoline thunks.
+ */
+ apply_retpolines(__retpoline_sites, __retpoline_sites_end);
+ apply_returns(__return_sites, __return_sites_end);
+
apply_alternatives(__alt_instructions, __alt_instructions_end);

#ifdef CONFIG_SMP
@@ -1009,10 +1312,13 @@ void text_poke_sync(void)
}

struct text_poke_loc {
- s32 rel_addr; /* addr := _stext + rel_addr */
- s32 rel32;
+ /* addr := _stext + rel_addr */
+ s32 rel_addr;
+ s32 disp;
+ u8 len;
u8 opcode;
const u8 text[POKE_MAX_OPCODE_SIZE];
+ /* see text_poke_bp_batch() */
u8 old;
};

@@ -1027,7 +1333,8 @@ static struct bp_patching_desc *bp_desc;
static __always_inline
struct bp_patching_desc *try_get_desc(struct bp_patching_desc **descp)
{
- struct bp_patching_desc *desc = __READ_ONCE(*descp); /* rcu_dereference */
+ /* rcu_dereference */
+ struct bp_patching_desc *desc = __READ_ONCE(*descp);

if (!desc || !arch_atomic_inc_not_zero(&desc->refs))
return NULL;
@@ -1061,7 +1368,7 @@ noinstr int poke_int3_handler(struct pt_regs *regs)
{
struct bp_patching_desc *desc;
struct text_poke_loc *tp;
- int len, ret = 0;
+ int ret = 0;
void *ip;

if (user_mode(regs))
@@ -1101,8 +1408,7 @@ noinstr int poke_int3_handler(struct pt_regs *regs)
goto out_put;
}

- len = text_opcode_size(tp->opcode);
- ip += len;
+ ip += tp->len;

switch (tp->opcode) {
case INT3_INSN_OPCODE:
@@ -1117,12 +1423,12 @@ noinstr int poke_int3_handler(struct pt_regs *regs)
break;

case CALL_INSN_OPCODE:
- int3_emulate_call(regs, (long)ip + tp->rel32);
+ int3_emulate_call(regs, (long)ip + tp->disp);
break;

case JMP32_INSN_OPCODE:
case JMP8_INSN_OPCODE:
- int3_emulate_jmp(regs, (long)ip + tp->rel32);
+ int3_emulate_jmp(regs, (long)ip + tp->disp);
break;

default:
@@ -1197,7 +1503,7 @@ static void text_poke_bp_batch(struct text_poke_loc *tp, unsigned int nr_entries
*/
for (do_sync = 0, i = 0; i < nr_entries; i++) {
u8 old[POKE_MAX_OPCODE_SIZE] = { tp[i].old, };
- int len = text_opcode_size(tp[i].opcode);
+ int len = tp[i].len;

if (len - INT3_INSN_SIZE > 0) {
memcpy(old + INT3_INSN_SIZE,
@@ -1274,20 +1580,36 @@ static void text_poke_loc_init(struct text_poke_loc *tp, void *addr,
const void *opcode, size_t len, const void *emulate)
{
struct insn insn;
+ int ret, i;

memcpy((void *)tp->text, opcode, len);
if (!emulate)
emulate = opcode;

- kernel_insn_init(&insn, emulate, MAX_INSN_SIZE);
- insn_get_length(&insn);
-
- BUG_ON(!insn_complete(&insn));
- BUG_ON(len != insn.length);
+ ret = insn_decode_kernel(&insn, emulate);
+ BUG_ON(ret < 0);

tp->rel_addr = addr - (void *)_stext;
+ tp->len = len;
tp->opcode = insn.opcode.bytes[0];

+ switch (tp->opcode) {
+ case RET_INSN_OPCODE:
+ case JMP32_INSN_OPCODE:
+ case JMP8_INSN_OPCODE:
+ /*
+ * Control flow instructions without implied execution of the
+ * next instruction can be padded with INT3.
+ */
+ for (i = insn.length; i < len; i++)
+ BUG_ON(tp->text[i] != INT3_INSN_OPCODE);
+ break;
+
+ default:
+ BUG_ON(len != insn.length);
+ };
+
+
switch (tp->opcode) {
case INT3_INSN_OPCODE:
case RET_INSN_OPCODE:
@@ -1296,7 +1618,7 @@ static void text_poke_loc_init(struct text_poke_loc *tp, void *addr,
case CALL_INSN_OPCODE:
case JMP32_INSN_OPCODE:
case JMP8_INSN_OPCODE:
- tp->rel32 = insn.immediate.value;
+ tp->disp = insn.immediate.value;
break;

default: /* assume NOP */
@@ -1304,13 +1626,13 @@ static void text_poke_loc_init(struct text_poke_loc *tp, void *addr,
case 2: /* NOP2 -- emulate as JMP8+0 */
BUG_ON(memcmp(emulate, ideal_nops[len], len));
tp->opcode = JMP8_INSN_OPCODE;
- tp->rel32 = 0;
+ tp->disp = 0;
break;

case 5: /* NOP5 -- emulate as JMP32+0 */
BUG_ON(memcmp(emulate, ideal_nops[NOP_ATOMIC5], len));
tp->opcode = JMP32_INSN_OPCODE;
- tp->rel32 = 0;
+ tp->disp = 0;
break;

default: /* unknown instruction */
diff --git a/arch/x86/kernel/cpu/amd.c b/arch/x86/kernel/cpu/amd.c
index acea05eed27d..8b9e3277a6ce 100644
--- a/arch/x86/kernel/cpu/amd.c
+++ b/arch/x86/kernel/cpu/amd.c
@@ -914,6 +914,28 @@ static void init_amd_bd(struct cpuinfo_x86 *c)
clear_rdrand_cpuid_bit(c);
}

+void init_spectral_chicken(struct cpuinfo_x86 *c)
+{
+#ifdef CONFIG_CPU_UNRET_ENTRY
+ u64 value;
+
+ /*
+ * On Zen2 we offer this chicken (bit) on the altar of Speculation.
+ *
+ * This suppresses speculation from the middle of a basic block, i.e. it
+ * suppresses non-branch predictions.
+ *
+ * We use STIBP as a heuristic to filter out Zen2 from the rest of F17H
+ */
+ if (!cpu_has(c, X86_FEATURE_HYPERVISOR) && cpu_has(c, X86_FEATURE_AMD_STIBP)) {
+ if (!rdmsrl_safe(MSR_ZEN2_SPECTRAL_CHICKEN, &value)) {
+ value |= MSR_ZEN2_SPECTRAL_CHICKEN_BIT;
+ wrmsrl_safe(MSR_ZEN2_SPECTRAL_CHICKEN, value);
+ }
+ }
+#endif
+}
+
static void init_amd_zn(struct cpuinfo_x86 *c)
{
set_cpu_cap(c, X86_FEATURE_ZEN);
@@ -922,12 +944,21 @@ static void init_amd_zn(struct cpuinfo_x86 *c)
node_reclaim_distance = 32;
#endif

- /*
- * Fix erratum 1076: CPB feature bit not being set in CPUID.
- * Always set it, except when running under a hypervisor.
- */
- if (!cpu_has(c, X86_FEATURE_HYPERVISOR) && !cpu_has(c, X86_FEATURE_CPB))
- set_cpu_cap(c, X86_FEATURE_CPB);
+ /* Fix up CPUID bits, but only if not virtualised. */
+ if (!cpu_has(c, X86_FEATURE_HYPERVISOR)) {
+
+ /* Erratum 1076: CPB feature bit not being set in CPUID. */
+ if (!cpu_has(c, X86_FEATURE_CPB))
+ set_cpu_cap(c, X86_FEATURE_CPB);
+
+ /*
+ * Zen3 (Fam19 model < 0x10) parts are not susceptible to
+ * Branch Type Confusion, but predate the allocation of the
+ * BTC_NO bit.
+ */
+ if (c->x86 == 0x19 && !cpu_has(c, X86_FEATURE_BTC_NO))
+ set_cpu_cap(c, X86_FEATURE_BTC_NO);
+ }
}

static void init_amd(struct cpuinfo_x86 *c)
@@ -959,7 +990,8 @@ static void init_amd(struct cpuinfo_x86 *c)
case 0x12: init_amd_ln(c); break;
case 0x15: init_amd_bd(c); break;
case 0x16: init_amd_jg(c); break;
- case 0x17: fallthrough;
+ case 0x17: init_spectral_chicken(c);
+ fallthrough;
case 0x19: init_amd_zn(c); break;
}

diff --git a/arch/x86/kernel/cpu/bugs.c b/arch/x86/kernel/cpu/bugs.c
index 2a21046846b6..bc6382f5ec27 100644
--- a/arch/x86/kernel/cpu/bugs.c
+++ b/arch/x86/kernel/cpu/bugs.c
@@ -38,6 +38,8 @@

static void __init spectre_v1_select_mitigation(void);
static void __init spectre_v2_select_mitigation(void);
+static void __init retbleed_select_mitigation(void);
+static void __init spectre_v2_user_select_mitigation(void);
static void __init ssb_select_mitigation(void);
static void __init l1tf_select_mitigation(void);
static void __init mds_select_mitigation(void);
@@ -47,16 +49,40 @@ static void __init taa_select_mitigation(void);
static void __init mmio_select_mitigation(void);
static void __init srbds_select_mitigation(void);

-/* The base value of the SPEC_CTRL MSR that always has to be preserved. */
+/* The base value of the SPEC_CTRL MSR without task-specific bits set */
u64 x86_spec_ctrl_base;
EXPORT_SYMBOL_GPL(x86_spec_ctrl_base);
+
+/* The current value of the SPEC_CTRL MSR with task-specific bits set */
+DEFINE_PER_CPU(u64, x86_spec_ctrl_current);
+EXPORT_SYMBOL_GPL(x86_spec_ctrl_current);
+
static DEFINE_MUTEX(spec_ctrl_mutex);

/*
- * The vendor and possibly platform specific bits which can be modified in
- * x86_spec_ctrl_base.
+ * Keep track of the SPEC_CTRL MSR value for the current task, which may differ
+ * from x86_spec_ctrl_base due to STIBP/SSB in __speculation_ctrl_update().
*/
-static u64 __ro_after_init x86_spec_ctrl_mask = SPEC_CTRL_IBRS;
+void write_spec_ctrl_current(u64 val, bool force)
+{
+ if (this_cpu_read(x86_spec_ctrl_current) == val)
+ return;
+
+ this_cpu_write(x86_spec_ctrl_current, val);
+
+ /*
+ * When KERNEL_IBRS this MSR is written on return-to-user, unless
+ * forced the update can be delayed until that time.
+ */
+ if (force || !cpu_feature_enabled(X86_FEATURE_KERNEL_IBRS))
+ wrmsrl(MSR_IA32_SPEC_CTRL, val);
+}
+
+u64 spec_ctrl_current(void)
+{
+ return this_cpu_read(x86_spec_ctrl_current);
+}
+EXPORT_SYMBOL_GPL(spec_ctrl_current);

/*
* AMD specific MSR info for Speculative Store Bypass control.
@@ -106,13 +132,21 @@ void __init check_bugs(void)
if (boot_cpu_has(X86_FEATURE_MSR_SPEC_CTRL))
rdmsrl(MSR_IA32_SPEC_CTRL, x86_spec_ctrl_base);

- /* Allow STIBP in MSR_SPEC_CTRL if supported */
- if (boot_cpu_has(X86_FEATURE_STIBP))
- x86_spec_ctrl_mask |= SPEC_CTRL_STIBP;
-
/* Select the proper CPU mitigations before patching alternatives: */
spectre_v1_select_mitigation();
spectre_v2_select_mitigation();
+ /*
+ * retbleed_select_mitigation() relies on the state set by
+ * spectre_v2_select_mitigation(); specifically it wants to know about
+ * spectre_v2=ibrs.
+ */
+ retbleed_select_mitigation();
+ /*
+ * spectre_v2_user_select_mitigation() relies on the state set by
+ * retbleed_select_mitigation(); specifically the STIBP selection is
+ * forced for UNRET.
+ */
+ spectre_v2_user_select_mitigation();
ssb_select_mitigation();
l1tf_select_mitigation();
md_clear_select_mitigation();
@@ -152,31 +186,17 @@ void __init check_bugs(void)
#endif
}

+/*
+ * NOTE: For VMX, this function is not called in the vmexit path.
+ * It uses vmx_spec_ctrl_restore_host() instead.
+ */
void
x86_virt_spec_ctrl(u64 guest_spec_ctrl, u64 guest_virt_spec_ctrl, bool setguest)
{
- u64 msrval, guestval, hostval = x86_spec_ctrl_base;
+ u64 msrval, guestval = guest_spec_ctrl, hostval = spec_ctrl_current();
struct thread_info *ti = current_thread_info();

- /* Is MSR_SPEC_CTRL implemented ? */
if (static_cpu_has(X86_FEATURE_MSR_SPEC_CTRL)) {
- /*
- * Restrict guest_spec_ctrl to supported values. Clear the
- * modifiable bits in the host base value and or the
- * modifiable bits from the guest value.
- */
- guestval = hostval & ~x86_spec_ctrl_mask;
- guestval |= guest_spec_ctrl & x86_spec_ctrl_mask;
-
- /* SSBD controlled in MSR_SPEC_CTRL */
- if (static_cpu_has(X86_FEATURE_SPEC_CTRL_SSBD) ||
- static_cpu_has(X86_FEATURE_AMD_SSBD))
- hostval |= ssbd_tif_to_spec_ctrl(ti->flags);
-
- /* Conditional STIBP enabled? */
- if (static_branch_unlikely(&switch_to_cond_stibp))
- hostval |= stibp_tif_to_spec_ctrl(ti->flags);
-
if (hostval != guestval) {
msrval = setguest ? guestval : hostval;
wrmsrl(MSR_IA32_SPEC_CTRL, msrval);
@@ -708,12 +728,180 @@ static int __init nospectre_v1_cmdline(char *str)
}
early_param("nospectre_v1", nospectre_v1_cmdline);

-#undef pr_fmt
-#define pr_fmt(fmt) "Spectre V2 : " fmt
-
static enum spectre_v2_mitigation spectre_v2_enabled __ro_after_init =
SPECTRE_V2_NONE;

+#undef pr_fmt
+#define pr_fmt(fmt) "RETBleed: " fmt
+
+enum retbleed_mitigation {
+ RETBLEED_MITIGATION_NONE,
+ RETBLEED_MITIGATION_UNRET,
+ RETBLEED_MITIGATION_IBPB,
+ RETBLEED_MITIGATION_IBRS,
+ RETBLEED_MITIGATION_EIBRS,
+};
+
+enum retbleed_mitigation_cmd {
+ RETBLEED_CMD_OFF,
+ RETBLEED_CMD_AUTO,
+ RETBLEED_CMD_UNRET,
+ RETBLEED_CMD_IBPB,
+};
+
+const char * const retbleed_strings[] = {
+ [RETBLEED_MITIGATION_NONE] = "Vulnerable",
+ [RETBLEED_MITIGATION_UNRET] = "Mitigation: untrained return thunk",
+ [RETBLEED_MITIGATION_IBPB] = "Mitigation: IBPB",
+ [RETBLEED_MITIGATION_IBRS] = "Mitigation: IBRS",
+ [RETBLEED_MITIGATION_EIBRS] = "Mitigation: Enhanced IBRS",
+};
+
+static enum retbleed_mitigation retbleed_mitigation __ro_after_init =
+ RETBLEED_MITIGATION_NONE;
+static enum retbleed_mitigation_cmd retbleed_cmd __ro_after_init =
+ RETBLEED_CMD_AUTO;
+
+static int __ro_after_init retbleed_nosmt = false;
+
+static int __init retbleed_parse_cmdline(char *str)
+{
+ if (!str)
+ return -EINVAL;
+
+ while (str) {
+ char *next = strchr(str, ',');
+ if (next) {
+ *next = 0;
+ next++;
+ }
+
+ if (!strcmp(str, "off")) {
+ retbleed_cmd = RETBLEED_CMD_OFF;
+ } else if (!strcmp(str, "auto")) {
+ retbleed_cmd = RETBLEED_CMD_AUTO;
+ } else if (!strcmp(str, "unret")) {
+ retbleed_cmd = RETBLEED_CMD_UNRET;
+ } else if (!strcmp(str, "ibpb")) {
+ retbleed_cmd = RETBLEED_CMD_IBPB;
+ } else if (!strcmp(str, "nosmt")) {
+ retbleed_nosmt = true;
+ } else {
+ pr_err("Ignoring unknown retbleed option (%s).", str);
+ }
+
+ str = next;
+ }
+
+ return 0;
+}
+early_param("retbleed", retbleed_parse_cmdline);
+
+#define RETBLEED_UNTRAIN_MSG "WARNING: BTB untrained return thunk mitigation is only effective on AMD/Hygon!\n"
+#define RETBLEED_INTEL_MSG "WARNING: Spectre v2 mitigation leaves CPU vulnerable to RETBleed attacks, data leaks possible!\n"
+
+static void __init retbleed_select_mitigation(void)
+{
+ bool mitigate_smt = false;
+
+ if (!boot_cpu_has_bug(X86_BUG_RETBLEED) || cpu_mitigations_off())
+ return;
+
+ switch (retbleed_cmd) {
+ case RETBLEED_CMD_OFF:
+ return;
+
+ case RETBLEED_CMD_UNRET:
+ if (IS_ENABLED(CONFIG_CPU_UNRET_ENTRY)) {
+ retbleed_mitigation = RETBLEED_MITIGATION_UNRET;
+ } else {
+ pr_err("WARNING: kernel not compiled with CPU_UNRET_ENTRY.\n");
+ goto do_cmd_auto;
+ }
+ break;
+
+ case RETBLEED_CMD_IBPB:
+ if (!boot_cpu_has(X86_FEATURE_IBPB)) {
+ pr_err("WARNING: CPU does not support IBPB.\n");
+ goto do_cmd_auto;
+ } else if (IS_ENABLED(CONFIG_CPU_IBPB_ENTRY)) {
+ retbleed_mitigation = RETBLEED_MITIGATION_IBPB;
+ } else {
+ pr_err("WARNING: kernel not compiled with CPU_IBPB_ENTRY.\n");
+ goto do_cmd_auto;
+ }
+ break;
+
+do_cmd_auto:
+ case RETBLEED_CMD_AUTO:
+ default:
+ if (boot_cpu_data.x86_vendor == X86_VENDOR_AMD ||
+ boot_cpu_data.x86_vendor == X86_VENDOR_HYGON) {
+ if (IS_ENABLED(CONFIG_CPU_UNRET_ENTRY))
+ retbleed_mitigation = RETBLEED_MITIGATION_UNRET;
+ else if (IS_ENABLED(CONFIG_CPU_IBPB_ENTRY) && boot_cpu_has(X86_FEATURE_IBPB))
+ retbleed_mitigation = RETBLEED_MITIGATION_IBPB;
+ }
+
+ /*
+ * The Intel mitigation (IBRS or eIBRS) was already selected in
+ * spectre_v2_select_mitigation(). 'retbleed_mitigation' will
+ * be set accordingly below.
+ */
+
+ break;
+ }
+
+ switch (retbleed_mitigation) {
+ case RETBLEED_MITIGATION_UNRET:
+ setup_force_cpu_cap(X86_FEATURE_RETHUNK);
+ setup_force_cpu_cap(X86_FEATURE_UNRET);
+
+ if (boot_cpu_data.x86_vendor != X86_VENDOR_AMD &&
+ boot_cpu_data.x86_vendor != X86_VENDOR_HYGON)
+ pr_err(RETBLEED_UNTRAIN_MSG);
+
+ mitigate_smt = true;
+ break;
+
+ case RETBLEED_MITIGATION_IBPB:
+ setup_force_cpu_cap(X86_FEATURE_ENTRY_IBPB);
+ mitigate_smt = true;
+ break;
+
+ default:
+ break;
+ }
+
+ if (mitigate_smt && !boot_cpu_has(X86_FEATURE_STIBP) &&
+ (retbleed_nosmt || cpu_mitigations_auto_nosmt()))
+ cpu_smt_disable(false);
+
+ /*
+ * Let IBRS trump all on Intel without affecting the effects of the
+ * retbleed= cmdline option.
+ */
+ if (boot_cpu_data.x86_vendor == X86_VENDOR_INTEL) {
+ switch (spectre_v2_enabled) {
+ case SPECTRE_V2_IBRS:
+ retbleed_mitigation = RETBLEED_MITIGATION_IBRS;
+ break;
+ case SPECTRE_V2_EIBRS:
+ case SPECTRE_V2_EIBRS_RETPOLINE:
+ case SPECTRE_V2_EIBRS_LFENCE:
+ retbleed_mitigation = RETBLEED_MITIGATION_EIBRS;
+ break;
+ default:
+ pr_err(RETBLEED_INTEL_MSG);
+ }
+ }
+
+ pr_info("%s\n", retbleed_strings[retbleed_mitigation]);
+}
+
+#undef pr_fmt
+#define pr_fmt(fmt) "Spectre V2 : " fmt
+
static enum spectre_v2_user_mitigation spectre_v2_user_stibp __ro_after_init =
SPECTRE_V2_USER_NONE;
static enum spectre_v2_user_mitigation spectre_v2_user_ibpb __ro_after_init =
@@ -784,6 +972,7 @@ enum spectre_v2_mitigation_cmd {
SPECTRE_V2_CMD_EIBRS,
SPECTRE_V2_CMD_EIBRS_RETPOLINE,
SPECTRE_V2_CMD_EIBRS_LFENCE,
+ SPECTRE_V2_CMD_IBRS,
};

enum spectre_v2_user_cmd {
@@ -824,13 +1013,15 @@ static void __init spec_v2_user_print_cond(const char *reason, bool secure)
pr_info("spectre_v2_user=%s forced on command line.\n", reason);
}

+static __ro_after_init enum spectre_v2_mitigation_cmd spectre_v2_cmd;
+
static enum spectre_v2_user_cmd __init
-spectre_v2_parse_user_cmdline(enum spectre_v2_mitigation_cmd v2_cmd)
+spectre_v2_parse_user_cmdline(void)
{
char arg[20];
int ret, i;

- switch (v2_cmd) {
+ switch (spectre_v2_cmd) {
case SPECTRE_V2_CMD_NONE:
return SPECTRE_V2_USER_CMD_NONE;
case SPECTRE_V2_CMD_FORCE:
@@ -856,15 +1047,16 @@ spectre_v2_parse_user_cmdline(enum spectre_v2_mitigation_cmd v2_cmd)
return SPECTRE_V2_USER_CMD_AUTO;
}

-static inline bool spectre_v2_in_eibrs_mode(enum spectre_v2_mitigation mode)
+static inline bool spectre_v2_in_ibrs_mode(enum spectre_v2_mitigation mode)
{
- return (mode == SPECTRE_V2_EIBRS ||
- mode == SPECTRE_V2_EIBRS_RETPOLINE ||
- mode == SPECTRE_V2_EIBRS_LFENCE);
+ return mode == SPECTRE_V2_IBRS ||
+ mode == SPECTRE_V2_EIBRS ||
+ mode == SPECTRE_V2_EIBRS_RETPOLINE ||
+ mode == SPECTRE_V2_EIBRS_LFENCE;
}

static void __init
-spectre_v2_user_select_mitigation(enum spectre_v2_mitigation_cmd v2_cmd)
+spectre_v2_user_select_mitigation(void)
{
enum spectre_v2_user_mitigation mode = SPECTRE_V2_USER_NONE;
bool smt_possible = IS_ENABLED(CONFIG_SMP);
@@ -877,7 +1069,7 @@ spectre_v2_user_select_mitigation(enum spectre_v2_mitigation_cmd v2_cmd)
cpu_smt_control == CPU_SMT_NOT_SUPPORTED)
smt_possible = false;

- cmd = spectre_v2_parse_user_cmdline(v2_cmd);
+ cmd = spectre_v2_parse_user_cmdline();
switch (cmd) {
case SPECTRE_V2_USER_CMD_NONE:
goto set_mode;
@@ -925,12 +1117,12 @@ spectre_v2_user_select_mitigation(enum spectre_v2_mitigation_cmd v2_cmd)
}

/*
- * If no STIBP, enhanced IBRS is enabled or SMT impossible, STIBP is not
- * required.
+ * If no STIBP, IBRS or enhanced IBRS is enabled, or SMT impossible,
+ * STIBP is not required.
*/
if (!boot_cpu_has(X86_FEATURE_STIBP) ||
!smt_possible ||
- spectre_v2_in_eibrs_mode(spectre_v2_enabled))
+ spectre_v2_in_ibrs_mode(spectre_v2_enabled))
return;

/*
@@ -942,6 +1134,13 @@ spectre_v2_user_select_mitigation(enum spectre_v2_mitigation_cmd v2_cmd)
boot_cpu_has(X86_FEATURE_AMD_STIBP_ALWAYS_ON))
mode = SPECTRE_V2_USER_STRICT_PREFERRED;

+ if (retbleed_mitigation == RETBLEED_MITIGATION_UNRET) {
+ if (mode != SPECTRE_V2_USER_STRICT &&
+ mode != SPECTRE_V2_USER_STRICT_PREFERRED)
+ pr_info("Selecting STIBP always-on mode to complement retbleed mitigation\n");
+ mode = SPECTRE_V2_USER_STRICT_PREFERRED;
+ }
+
spectre_v2_user_stibp = mode;

set_mode:
@@ -955,6 +1154,7 @@ static const char * const spectre_v2_strings[] = {
[SPECTRE_V2_EIBRS] = "Mitigation: Enhanced IBRS",
[SPECTRE_V2_EIBRS_LFENCE] = "Mitigation: Enhanced IBRS + LFENCE",
[SPECTRE_V2_EIBRS_RETPOLINE] = "Mitigation: Enhanced IBRS + Retpolines",
+ [SPECTRE_V2_IBRS] = "Mitigation: IBRS",
};

static const struct {
@@ -972,6 +1172,7 @@ static const struct {
{ "eibrs,lfence", SPECTRE_V2_CMD_EIBRS_LFENCE, false },
{ "eibrs,retpoline", SPECTRE_V2_CMD_EIBRS_RETPOLINE, false },
{ "auto", SPECTRE_V2_CMD_AUTO, false },
+ { "ibrs", SPECTRE_V2_CMD_IBRS, false },
};

static void __init spec_v2_print_cond(const char *reason, bool secure)
@@ -1034,6 +1235,30 @@ static enum spectre_v2_mitigation_cmd __init spectre_v2_parse_cmdline(void)
return SPECTRE_V2_CMD_AUTO;
}

+ if (cmd == SPECTRE_V2_CMD_IBRS && !IS_ENABLED(CONFIG_CPU_IBRS_ENTRY)) {
+ pr_err("%s selected but not compiled in. Switching to AUTO select\n",
+ mitigation_options[i].option);
+ return SPECTRE_V2_CMD_AUTO;
+ }
+
+ if (cmd == SPECTRE_V2_CMD_IBRS && boot_cpu_data.x86_vendor != X86_VENDOR_INTEL) {
+ pr_err("%s selected but not Intel CPU. Switching to AUTO select\n",
+ mitigation_options[i].option);
+ return SPECTRE_V2_CMD_AUTO;
+ }
+
+ if (cmd == SPECTRE_V2_CMD_IBRS && !boot_cpu_has(X86_FEATURE_IBRS)) {
+ pr_err("%s selected but CPU doesn't have IBRS. Switching to AUTO select\n",
+ mitigation_options[i].option);
+ return SPECTRE_V2_CMD_AUTO;
+ }
+
+ if (cmd == SPECTRE_V2_CMD_IBRS && boot_cpu_has(X86_FEATURE_XENPV)) {
+ pr_err("%s selected but running as XenPV guest. Switching to AUTO select\n",
+ mitigation_options[i].option);
+ return SPECTRE_V2_CMD_AUTO;
+ }
+
spec_v2_print_cond(mitigation_options[i].option,
mitigation_options[i].secure);
return cmd;
@@ -1049,6 +1274,22 @@ static enum spectre_v2_mitigation __init spectre_v2_select_retpoline(void)
return SPECTRE_V2_RETPOLINE;
}

+/* Disable in-kernel use of non-RSB RET predictors */
+static void __init spec_ctrl_disable_kernel_rrsba(void)
+{
+ u64 ia32_cap;
+
+ if (!boot_cpu_has(X86_FEATURE_RRSBA_CTRL))
+ return;
+
+ ia32_cap = x86_read_arch_cap_msr();
+
+ if (ia32_cap & ARCH_CAP_RRSBA) {
+ x86_spec_ctrl_base |= SPEC_CTRL_RRSBA_DIS_S;
+ write_spec_ctrl_current(x86_spec_ctrl_base, true);
+ }
+}
+
static void __init spectre_v2_select_mitigation(void)
{
enum spectre_v2_mitigation_cmd cmd = spectre_v2_parse_cmdline();
@@ -1073,6 +1314,15 @@ static void __init spectre_v2_select_mitigation(void)
break;
}

+ if (IS_ENABLED(CONFIG_CPU_IBRS_ENTRY) &&
+ boot_cpu_has_bug(X86_BUG_RETBLEED) &&
+ retbleed_cmd != RETBLEED_CMD_OFF &&
+ boot_cpu_has(X86_FEATURE_IBRS) &&
+ boot_cpu_data.x86_vendor == X86_VENDOR_INTEL) {
+ mode = SPECTRE_V2_IBRS;
+ break;
+ }
+
mode = spectre_v2_select_retpoline();
break;

@@ -1089,6 +1339,10 @@ static void __init spectre_v2_select_mitigation(void)
mode = spectre_v2_select_retpoline();
break;

+ case SPECTRE_V2_CMD_IBRS:
+ mode = SPECTRE_V2_IBRS;
+ break;
+
case SPECTRE_V2_CMD_EIBRS:
mode = SPECTRE_V2_EIBRS;
break;
@@ -1105,10 +1359,9 @@ static void __init spectre_v2_select_mitigation(void)
if (mode == SPECTRE_V2_EIBRS && unprivileged_ebpf_enabled())
pr_err(SPECTRE_V2_EIBRS_EBPF_MSG);

- if (spectre_v2_in_eibrs_mode(mode)) {
- /* Force it so VMEXIT will restore correctly */
+ if (spectre_v2_in_ibrs_mode(mode)) {
x86_spec_ctrl_base |= SPEC_CTRL_IBRS;
- wrmsrl(MSR_IA32_SPEC_CTRL, x86_spec_ctrl_base);
+ write_spec_ctrl_current(x86_spec_ctrl_base, true);
}

switch (mode) {
@@ -1116,6 +1369,10 @@ static void __init spectre_v2_select_mitigation(void)
case SPECTRE_V2_EIBRS:
break;

+ case SPECTRE_V2_IBRS:
+ setup_force_cpu_cap(X86_FEATURE_KERNEL_IBRS);
+ break;
+
case SPECTRE_V2_LFENCE:
case SPECTRE_V2_EIBRS_LFENCE:
setup_force_cpu_cap(X86_FEATURE_RETPOLINE_LFENCE);
@@ -1127,43 +1384,107 @@ static void __init spectre_v2_select_mitigation(void)
break;
}

+ /*
+ * Disable alternate RSB predictions in kernel when indirect CALLs and
+ * JMPs gets protection against BHI and Intramode-BTI, but RET
+ * prediction from a non-RSB predictor is still a risk.
+ */
+ if (mode == SPECTRE_V2_EIBRS_LFENCE ||
+ mode == SPECTRE_V2_EIBRS_RETPOLINE ||
+ mode == SPECTRE_V2_RETPOLINE)
+ spec_ctrl_disable_kernel_rrsba();
+
spectre_v2_enabled = mode;
pr_info("%s\n", spectre_v2_strings[mode]);

/*
- * If spectre v2 protection has been enabled, unconditionally fill
- * RSB during a context switch; this protects against two independent
- * issues:
+ * If Spectre v2 protection has been enabled, fill the RSB during a
+ * context switch. In general there are two types of RSB attacks
+ * across context switches, for which the CALLs/RETs may be unbalanced.
*
- * - RSB underflow (and switch to BTB) on Skylake+
- * - SpectreRSB variant of spectre v2 on X86_BUG_SPECTRE_V2 CPUs
+ * 1) RSB underflow
+ *
+ * Some Intel parts have "bottomless RSB". When the RSB is empty,
+ * speculated return targets may come from the branch predictor,
+ * which could have a user-poisoned BTB or BHB entry.
+ *
+ * AMD has it even worse: *all* returns are speculated from the BTB,
+ * regardless of the state of the RSB.
+ *
+ * When IBRS or eIBRS is enabled, the "user -> kernel" attack
+ * scenario is mitigated by the IBRS branch prediction isolation
+ * properties, so the RSB buffer filling wouldn't be necessary to
+ * protect against this type of attack.
+ *
+ * The "user -> user" attack scenario is mitigated by RSB filling.
+ *
+ * 2) Poisoned RSB entry
+ *
+ * If the 'next' in-kernel return stack is shorter than 'prev',
+ * 'next' could be tricked into speculating with a user-poisoned RSB
+ * entry.
+ *
+ * The "user -> kernel" attack scenario is mitigated by SMEP and
+ * eIBRS.
+ *
+ * The "user -> user" scenario, also known as SpectreBHB, requires
+ * RSB clearing.
+ *
+ * So to mitigate all cases, unconditionally fill RSB on context
+ * switches.
+ *
+ * FIXME: Is this pointless for retbleed-affected AMD?
*/
setup_force_cpu_cap(X86_FEATURE_RSB_CTXSW);
pr_info("Spectre v2 / SpectreRSB mitigation: Filling RSB on context switch\n");

/*
- * Retpoline means the kernel is safe because it has no indirect
- * branches. Enhanced IBRS protects firmware too, so, enable restricted
- * speculation around firmware calls only when Enhanced IBRS isn't
- * supported.
+ * Similar to context switches, there are two types of RSB attacks
+ * after vmexit:
+ *
+ * 1) RSB underflow
+ *
+ * 2) Poisoned RSB entry
+ *
+ * When retpoline is enabled, both are mitigated by filling/clearing
+ * the RSB.
+ *
+ * When IBRS is enabled, while #1 would be mitigated by the IBRS branch
+ * prediction isolation protections, RSB still needs to be cleared
+ * because of #2. Note that SMEP provides no protection here, unlike
+ * user-space-poisoned RSB entries.
+ *
+ * eIBRS, on the other hand, has RSB-poisoning protections, so it
+ * doesn't need RSB clearing after vmexit.
+ */
+ if (boot_cpu_has(X86_FEATURE_RETPOLINE) ||
+ boot_cpu_has(X86_FEATURE_KERNEL_IBRS))
+ setup_force_cpu_cap(X86_FEATURE_RSB_VMEXIT);
+
+ /*
+ * Retpoline protects the kernel, but doesn't protect firmware. IBRS
+ * and Enhanced IBRS protect firmware too, so enable IBRS around
+ * firmware calls only when IBRS / Enhanced IBRS aren't otherwise
+ * enabled.
*
* Use "mode" to check Enhanced IBRS instead of boot_cpu_has(), because
* the user might select retpoline on the kernel command line and if
* the CPU supports Enhanced IBRS, kernel might un-intentionally not
* enable IBRS around firmware calls.
*/
- if (boot_cpu_has(X86_FEATURE_IBRS) && !spectre_v2_in_eibrs_mode(mode)) {
+ if (boot_cpu_has(X86_FEATURE_IBRS) && !spectre_v2_in_ibrs_mode(mode)) {
setup_force_cpu_cap(X86_FEATURE_USE_IBRS_FW);
pr_info("Enabling Restricted Speculation for firmware calls\n");
}

/* Set up IBPB and STIBP depending on the general spectre V2 command */
- spectre_v2_user_select_mitigation(cmd);
+ spectre_v2_cmd = cmd;
}

static void update_stibp_msr(void * __unused)
{
- wrmsrl(MSR_IA32_SPEC_CTRL, x86_spec_ctrl_base);
+ u64 val = spec_ctrl_current() | (x86_spec_ctrl_base & SPEC_CTRL_STIBP);
+ write_spec_ctrl_current(val, true);
}

/* Update x86_spec_ctrl_base in case SMT state changed. */
@@ -1379,16 +1700,6 @@ static enum ssb_mitigation __init __ssb_select_mitigation(void)
break;
}

- /*
- * If SSBD is controlled by the SPEC_CTRL MSR, then set the proper
- * bit in the mask to allow guests to use the mitigation even in the
- * case where the host does not enable it.
- */
- if (static_cpu_has(X86_FEATURE_SPEC_CTRL_SSBD) ||
- static_cpu_has(X86_FEATURE_AMD_SSBD)) {
- x86_spec_ctrl_mask |= SPEC_CTRL_SSBD;
- }
-
/*
* We have three CPU feature flags that are in play here:
* - X86_BUG_SPEC_STORE_BYPASS - CPU is susceptible.
@@ -1406,7 +1717,7 @@ static enum ssb_mitigation __init __ssb_select_mitigation(void)
x86_amd_ssb_disable();
} else {
x86_spec_ctrl_base |= SPEC_CTRL_SSBD;
- wrmsrl(MSR_IA32_SPEC_CTRL, x86_spec_ctrl_base);
+ write_spec_ctrl_current(x86_spec_ctrl_base, true);
}
}

@@ -1624,7 +1935,7 @@ int arch_prctl_spec_ctrl_get(struct task_struct *task, unsigned long which)
void x86_spec_ctrl_setup_ap(void)
{
if (boot_cpu_has(X86_FEATURE_MSR_SPEC_CTRL))
- wrmsrl(MSR_IA32_SPEC_CTRL, x86_spec_ctrl_base);
+ write_spec_ctrl_current(x86_spec_ctrl_base, true);

if (ssb_mode == SPEC_STORE_BYPASS_DISABLE)
x86_amd_ssb_disable();
@@ -1861,7 +2172,7 @@ static ssize_t mmio_stale_data_show_state(char *buf)

static char *stibp_state(void)
{
- if (spectre_v2_in_eibrs_mode(spectre_v2_enabled))
+ if (spectre_v2_in_ibrs_mode(spectre_v2_enabled))
return "";

switch (spectre_v2_user_stibp) {
@@ -1917,6 +2228,24 @@ static ssize_t srbds_show_state(char *buf)
return sprintf(buf, "%s\n", srbds_strings[srbds_mitigation]);
}

+static ssize_t retbleed_show_state(char *buf)
+{
+ if (retbleed_mitigation == RETBLEED_MITIGATION_UNRET) {
+ if (boot_cpu_data.x86_vendor != X86_VENDOR_AMD &&
+ boot_cpu_data.x86_vendor != X86_VENDOR_HYGON)
+ return sprintf(buf, "Vulnerable: untrained return thunk on non-Zen uarch\n");
+
+ return sprintf(buf, "%s; SMT %s\n",
+ retbleed_strings[retbleed_mitigation],
+ !sched_smt_active() ? "disabled" :
+ spectre_v2_user_stibp == SPECTRE_V2_USER_STRICT ||
+ spectre_v2_user_stibp == SPECTRE_V2_USER_STRICT_PREFERRED ?
+ "enabled with STIBP protection" : "vulnerable");
+ }
+
+ return sprintf(buf, "%s\n", retbleed_strings[retbleed_mitigation]);
+}
+
static ssize_t cpu_show_common(struct device *dev, struct device_attribute *attr,
char *buf, unsigned int bug)
{
@@ -1962,6 +2291,9 @@ static ssize_t cpu_show_common(struct device *dev, struct device_attribute *attr
case X86_BUG_MMIO_STALE_DATA:
return mmio_stale_data_show_state(buf);

+ case X86_BUG_RETBLEED:
+ return retbleed_show_state(buf);
+
default:
break;
}
@@ -2018,4 +2350,9 @@ ssize_t cpu_show_mmio_stale_data(struct device *dev, struct device_attribute *at
{
return cpu_show_common(dev, attr, buf, X86_BUG_MMIO_STALE_DATA);
}
+
+ssize_t cpu_show_retbleed(struct device *dev, struct device_attribute *attr, char *buf)
+{
+ return cpu_show_common(dev, attr, buf, X86_BUG_RETBLEED);
+}
#endif
diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c
index 4917c2698ac1..901352bd3b42 100644
--- a/arch/x86/kernel/cpu/common.c
+++ b/arch/x86/kernel/cpu/common.c
@@ -1092,48 +1092,60 @@ static const __initconst struct x86_cpu_id cpu_vuln_whitelist[] = {
{}
};

+#define VULNBL(vendor, family, model, blacklist) \
+ X86_MATCH_VENDOR_FAM_MODEL(vendor, family, model, blacklist)
+
#define VULNBL_INTEL_STEPPINGS(model, steppings, issues) \
X86_MATCH_VENDOR_FAM_MODEL_STEPPINGS_FEATURE(INTEL, 6, \
INTEL_FAM6_##model, steppings, \
X86_FEATURE_ANY, issues)

+#define VULNBL_AMD(family, blacklist) \
+ VULNBL(AMD, family, X86_MODEL_ANY, blacklist)
+
+#define VULNBL_HYGON(family, blacklist) \
+ VULNBL(HYGON, family, X86_MODEL_ANY, blacklist)
+
#define SRBDS BIT(0)
/* CPU is affected by X86_BUG_MMIO_STALE_DATA */
#define MMIO BIT(1)
/* CPU is affected by Shared Buffers Data Sampling (SBDS), a variant of X86_BUG_MMIO_STALE_DATA */
#define MMIO_SBDS BIT(2)
+/* CPU is affected by RETbleed, speculating where you would not expect it */
+#define RETBLEED BIT(3)

static const struct x86_cpu_id cpu_vuln_blacklist[] __initconst = {
VULNBL_INTEL_STEPPINGS(IVYBRIDGE, X86_STEPPING_ANY, SRBDS),
VULNBL_INTEL_STEPPINGS(HASWELL, X86_STEPPING_ANY, SRBDS),
VULNBL_INTEL_STEPPINGS(HASWELL_L, X86_STEPPING_ANY, SRBDS),
VULNBL_INTEL_STEPPINGS(HASWELL_G, X86_STEPPING_ANY, SRBDS),
- VULNBL_INTEL_STEPPINGS(HASWELL_X, BIT(2) | BIT(4), MMIO),
- VULNBL_INTEL_STEPPINGS(BROADWELL_D, X86_STEPPINGS(0x3, 0x5), MMIO),
+ VULNBL_INTEL_STEPPINGS(HASWELL_X, X86_STEPPING_ANY, MMIO),
+ VULNBL_INTEL_STEPPINGS(BROADWELL_D, X86_STEPPING_ANY, MMIO),
VULNBL_INTEL_STEPPINGS(BROADWELL_G, X86_STEPPING_ANY, SRBDS),
VULNBL_INTEL_STEPPINGS(BROADWELL_X, X86_STEPPING_ANY, MMIO),
VULNBL_INTEL_STEPPINGS(BROADWELL, X86_STEPPING_ANY, SRBDS),
- VULNBL_INTEL_STEPPINGS(SKYLAKE_L, X86_STEPPINGS(0x3, 0x3), SRBDS | MMIO),
- VULNBL_INTEL_STEPPINGS(SKYLAKE_L, X86_STEPPING_ANY, SRBDS),
- VULNBL_INTEL_STEPPINGS(SKYLAKE_X, BIT(3) | BIT(4) | BIT(6) |
- BIT(7) | BIT(0xB), MMIO),
- VULNBL_INTEL_STEPPINGS(SKYLAKE, X86_STEPPINGS(0x3, 0x3), SRBDS | MMIO),
- VULNBL_INTEL_STEPPINGS(SKYLAKE, X86_STEPPING_ANY, SRBDS),
- VULNBL_INTEL_STEPPINGS(KABYLAKE_L, X86_STEPPINGS(0x9, 0xC), SRBDS | MMIO),
- VULNBL_INTEL_STEPPINGS(KABYLAKE_L, X86_STEPPINGS(0x0, 0x8), SRBDS),
- VULNBL_INTEL_STEPPINGS(KABYLAKE, X86_STEPPINGS(0x9, 0xD), SRBDS | MMIO),
- VULNBL_INTEL_STEPPINGS(KABYLAKE, X86_STEPPINGS(0x0, 0x8), SRBDS),
- VULNBL_INTEL_STEPPINGS(ICELAKE_L, X86_STEPPINGS(0x5, 0x5), MMIO | MMIO_SBDS),
- VULNBL_INTEL_STEPPINGS(ICELAKE_D, X86_STEPPINGS(0x1, 0x1), MMIO),
- VULNBL_INTEL_STEPPINGS(ICELAKE_X, X86_STEPPINGS(0x4, 0x6), MMIO),
- VULNBL_INTEL_STEPPINGS(COMETLAKE, BIT(2) | BIT(3) | BIT(5), MMIO | MMIO_SBDS),
- VULNBL_INTEL_STEPPINGS(COMETLAKE_L, X86_STEPPINGS(0x1, 0x1), MMIO | MMIO_SBDS),
- VULNBL_INTEL_STEPPINGS(COMETLAKE_L, X86_STEPPINGS(0x0, 0x0), MMIO),
- VULNBL_INTEL_STEPPINGS(LAKEFIELD, X86_STEPPINGS(0x1, 0x1), MMIO | MMIO_SBDS),
- VULNBL_INTEL_STEPPINGS(ROCKETLAKE, X86_STEPPINGS(0x1, 0x1), MMIO),
- VULNBL_INTEL_STEPPINGS(ATOM_TREMONT, X86_STEPPINGS(0x1, 0x1), MMIO | MMIO_SBDS),
+ VULNBL_INTEL_STEPPINGS(SKYLAKE_L, X86_STEPPING_ANY, SRBDS | MMIO | RETBLEED),
+ VULNBL_INTEL_STEPPINGS(SKYLAKE_X, X86_STEPPING_ANY, MMIO | RETBLEED),
+ VULNBL_INTEL_STEPPINGS(SKYLAKE, X86_STEPPING_ANY, SRBDS | MMIO | RETBLEED),
+ VULNBL_INTEL_STEPPINGS(KABYLAKE_L, X86_STEPPING_ANY, SRBDS | MMIO | RETBLEED),
+ VULNBL_INTEL_STEPPINGS(KABYLAKE, X86_STEPPING_ANY, SRBDS | MMIO | RETBLEED),
+ VULNBL_INTEL_STEPPINGS(CANNONLAKE_L, X86_STEPPING_ANY, RETBLEED),
+ VULNBL_INTEL_STEPPINGS(ICELAKE_L, X86_STEPPING_ANY, MMIO | MMIO_SBDS | RETBLEED),
+ VULNBL_INTEL_STEPPINGS(ICELAKE_D, X86_STEPPING_ANY, MMIO),
+ VULNBL_INTEL_STEPPINGS(ICELAKE_X, X86_STEPPING_ANY, MMIO),
+ VULNBL_INTEL_STEPPINGS(COMETLAKE, X86_STEPPING_ANY, MMIO | MMIO_SBDS | RETBLEED),
+ VULNBL_INTEL_STEPPINGS(COMETLAKE_L, X86_STEPPINGS(0x0, 0x0), MMIO | RETBLEED),
+ VULNBL_INTEL_STEPPINGS(COMETLAKE_L, X86_STEPPING_ANY, MMIO | MMIO_SBDS | RETBLEED),
+ VULNBL_INTEL_STEPPINGS(LAKEFIELD, X86_STEPPING_ANY, MMIO | MMIO_SBDS | RETBLEED),
+ VULNBL_INTEL_STEPPINGS(ROCKETLAKE, X86_STEPPING_ANY, MMIO | RETBLEED),
+ VULNBL_INTEL_STEPPINGS(ATOM_TREMONT, X86_STEPPING_ANY, MMIO | MMIO_SBDS),
VULNBL_INTEL_STEPPINGS(ATOM_TREMONT_D, X86_STEPPING_ANY, MMIO),
- VULNBL_INTEL_STEPPINGS(ATOM_TREMONT_L, X86_STEPPINGS(0x0, 0x0), MMIO | MMIO_SBDS),
+ VULNBL_INTEL_STEPPINGS(ATOM_TREMONT_L, X86_STEPPING_ANY, MMIO | MMIO_SBDS),
+
+ VULNBL_AMD(0x15, RETBLEED),
+ VULNBL_AMD(0x16, RETBLEED),
+ VULNBL_AMD(0x17, RETBLEED),
+ VULNBL_HYGON(0x18, RETBLEED),
{}
};

@@ -1235,6 +1247,11 @@ static void __init cpu_set_bug_bits(struct cpuinfo_x86 *c)
!arch_cap_mmio_immune(ia32_cap))
setup_force_cpu_bug(X86_BUG_MMIO_STALE_DATA);

+ if (!cpu_has(c, X86_FEATURE_BTC_NO)) {
+ if (cpu_matches(cpu_vuln_blacklist, RETBLEED) || (ia32_cap & ARCH_CAP_RSBA))
+ setup_force_cpu_bug(X86_BUG_RETBLEED);
+ }
+
if (cpu_matches(cpu_vuln_whitelist, NO_MELTDOWN))
return;

diff --git a/arch/x86/kernel/cpu/cpu.h b/arch/x86/kernel/cpu/cpu.h
index 093f5fc860e3..91df90abc1d9 100644
--- a/arch/x86/kernel/cpu/cpu.h
+++ b/arch/x86/kernel/cpu/cpu.h
@@ -60,6 +60,8 @@ extern void tsx_disable(void);
static inline void tsx_init(void) { }
#endif /* CONFIG_CPU_SUP_INTEL */

+extern void init_spectral_chicken(struct cpuinfo_x86 *c);
+
extern void get_cpu_cap(struct cpuinfo_x86 *c);
extern void get_cpu_address_sizes(struct cpuinfo_x86 *c);
extern void cpu_detect_cache_sizes(struct cpuinfo_x86 *c);
diff --git a/arch/x86/kernel/cpu/hygon.c b/arch/x86/kernel/cpu/hygon.c
index b78c471ec344..774ca6bfda9f 100644
--- a/arch/x86/kernel/cpu/hygon.c
+++ b/arch/x86/kernel/cpu/hygon.c
@@ -318,6 +318,12 @@ static void init_hygon(struct cpuinfo_x86 *c)
/* get apicid instead of initial apic id from cpuid */
c->apicid = hard_smp_processor_id();

+ /*
+ * XXX someone from Hygon needs to confirm this DTRT
+ *
+ init_spectral_chicken(c);
+ */
+
set_cpu_cap(c, X86_FEATURE_ZEN);
set_cpu_cap(c, X86_FEATURE_CPB);

diff --git a/arch/x86/kernel/cpu/scattered.c b/arch/x86/kernel/cpu/scattered.c
index 866c9a9bcdee..82fe492121bb 100644
--- a/arch/x86/kernel/cpu/scattered.c
+++ b/arch/x86/kernel/cpu/scattered.c
@@ -26,6 +26,7 @@ struct cpuid_bit {
static const struct cpuid_bit cpuid_bits[] = {
{ X86_FEATURE_APERFMPERF, CPUID_ECX, 0, 0x00000006, 0 },
{ X86_FEATURE_EPB, CPUID_ECX, 3, 0x00000006, 0 },
+ { X86_FEATURE_RRSBA_CTRL, CPUID_EDX, 2, 0x00000007, 2 },
{ X86_FEATURE_CQM_LLC, CPUID_EDX, 1, 0x0000000f, 0 },
{ X86_FEATURE_CQM_OCCUP_LLC, CPUID_EDX, 0, 0x0000000f, 1 },
{ X86_FEATURE_CQM_MBM_TOTAL, CPUID_EDX, 1, 0x0000000f, 1 },
diff --git a/arch/x86/kernel/ftrace.c b/arch/x86/kernel/ftrace.c
index 7edbd5ee5ed4..dca5cf82144c 100644
--- a/arch/x86/kernel/ftrace.c
+++ b/arch/x86/kernel/ftrace.c
@@ -308,7 +308,7 @@ union ftrace_op_code_union {
} __attribute__((packed));
};

-#define RET_SIZE 1
+#define RET_SIZE (IS_ENABLED(CONFIG_RETPOLINE) ? 5 : 1 + IS_ENABLED(CONFIG_SLS))

static unsigned long
create_trampoline(struct ftrace_ops *ops, unsigned int *tramp_size)
@@ -367,7 +367,10 @@ create_trampoline(struct ftrace_ops *ops, unsigned int *tramp_size)

/* The trampoline ends with ret(q) */
retq = (unsigned long)ftrace_stub;
- ret = copy_from_kernel_nofault(ip, (void *)retq, RET_SIZE);
+ if (cpu_feature_enabled(X86_FEATURE_RETHUNK))
+ memcpy(ip, text_gen_insn(JMP32_INSN_OPCODE, ip, &__x86_return_thunk), JMP32_INSN_SIZE);
+ else
+ ret = copy_from_kernel_nofault(ip, (void *)retq, RET_SIZE);
if (WARN_ON(ret < 0))
goto fail;

diff --git a/arch/x86/kernel/ftrace_32.S b/arch/x86/kernel/ftrace_32.S
index e405fe1a8bf4..a0ed0e4a2c0c 100644
--- a/arch/x86/kernel/ftrace_32.S
+++ b/arch/x86/kernel/ftrace_32.S
@@ -19,7 +19,7 @@
#endif

SYM_FUNC_START(__fentry__)
- ret
+ RET
SYM_FUNC_END(__fentry__)
EXPORT_SYMBOL(__fentry__)

@@ -84,7 +84,7 @@ ftrace_graph_call:

/* This is weak to keep gas from relaxing the jumps */
SYM_INNER_LABEL_ALIGN(ftrace_stub, SYM_L_WEAK)
- ret
+ RET
SYM_CODE_END(ftrace_caller)

SYM_CODE_START(ftrace_regs_caller)
@@ -177,7 +177,7 @@ SYM_CODE_START(ftrace_graph_caller)
popl %edx
popl %ecx
popl %eax
- ret
+ RET
SYM_CODE_END(ftrace_graph_caller)

.globl return_to_handler
diff --git a/arch/x86/kernel/ftrace_64.S b/arch/x86/kernel/ftrace_64.S
index ac3d5f22fe64..e3a375185a1b 100644
--- a/arch/x86/kernel/ftrace_64.S
+++ b/arch/x86/kernel/ftrace_64.S
@@ -132,7 +132,7 @@
#ifdef CONFIG_DYNAMIC_FTRACE

SYM_FUNC_START(__fentry__)
- retq
+ RET
SYM_FUNC_END(__fentry__)
EXPORT_SYMBOL(__fentry__)

@@ -170,10 +170,11 @@ SYM_INNER_LABEL(ftrace_graph_call, SYM_L_GLOBAL)

/*
* This is weak to keep gas from relaxing the jumps.
- * It is also used to copy the retq for trampolines.
+ * It is also used to copy the RET for trampolines.
*/
SYM_INNER_LABEL_ALIGN(ftrace_stub, SYM_L_WEAK)
- retq
+ UNWIND_HINT_FUNC
+ RET
SYM_FUNC_END(ftrace_epilogue)

SYM_FUNC_START(ftrace_regs_caller)
@@ -265,7 +266,7 @@ SYM_INNER_LABEL(ftrace_regs_caller_end, SYM_L_GLOBAL)
restore_mcount_regs 8
/* Restore flags */
popfq
- UNWIND_HINT_RET_OFFSET
+ UNWIND_HINT_FUNC
jmp ftrace_epilogue

SYM_FUNC_END(ftrace_regs_caller)
@@ -287,7 +288,7 @@ fgraph_trace:
#endif

SYM_INNER_LABEL(ftrace_stub, SYM_L_GLOBAL)
- retq
+ RET

trace:
/* save_mcount_regs fills in first two parameters */
@@ -319,7 +320,7 @@ SYM_FUNC_START(ftrace_graph_caller)

restore_mcount_regs

- retq
+ RET
SYM_FUNC_END(ftrace_graph_caller)

SYM_CODE_START(return_to_handler)
diff --git a/arch/x86/kernel/head_32.S b/arch/x86/kernel/head_32.S
index 7ed84c282233..3f1691b89231 100644
--- a/arch/x86/kernel/head_32.S
+++ b/arch/x86/kernel/head_32.S
@@ -23,6 +23,7 @@
#include <asm/cpufeatures.h>
#include <asm/percpu.h>
#include <asm/nops.h>
+#include <asm/nospec-branch.h>
#include <asm/bootparam.h>
#include <asm/export.h>
#include <asm/pgtable_32.h>
@@ -354,7 +355,7 @@ setup_once:
#endif

andl $0,setup_once_ref /* Once is enough, thanks */
- ret
+ RET

SYM_FUNC_START(early_idt_handler_array)
# 36(%esp) %eflags
diff --git a/arch/x86/kernel/head_64.S b/arch/x86/kernel/head_64.S
index 3c417734790f..0424c2a6c15b 100644
--- a/arch/x86/kernel/head_64.S
+++ b/arch/x86/kernel/head_64.S
@@ -321,6 +321,8 @@ SYM_CODE_END(start_cpu0)
SYM_CODE_START_NOALIGN(vc_boot_ghcb)
UNWIND_HINT_IRET_REGS offset=8

+ ANNOTATE_UNRET_END
+
/* Build pt_regs */
PUSH_AND_CLEAR_REGS

@@ -378,6 +380,7 @@ SYM_CODE_START(early_idt_handler_array)
SYM_CODE_END(early_idt_handler_array)

SYM_CODE_START_LOCAL(early_idt_handler_common)
+ ANNOTATE_UNRET_END
/*
* The stack is the hardware frame, an error code or zero, and the
* vector number.
@@ -424,6 +427,8 @@ SYM_CODE_END(early_idt_handler_common)
SYM_CODE_START_NOALIGN(vc_no_ghcb)
UNWIND_HINT_IRET_REGS offset=8

+ ANNOTATE_UNRET_END
+
/* Build pt_regs */
PUSH_AND_CLEAR_REGS

diff --git a/arch/x86/kernel/irqflags.S b/arch/x86/kernel/irqflags.S
index 0db0375235b4..a9c36400bdf8 100644
--- a/arch/x86/kernel/irqflags.S
+++ b/arch/x86/kernel/irqflags.S
@@ -10,7 +10,7 @@
SYM_FUNC_START(native_save_fl)
pushf
pop %_ASM_AX
- ret
+ RET
SYM_FUNC_END(native_save_fl)
EXPORT_SYMBOL(native_save_fl)

@@ -21,6 +21,6 @@ EXPORT_SYMBOL(native_save_fl)
SYM_FUNC_START(native_restore_fl)
push %_ASM_ARG1
popf
- ret
+ RET
SYM_FUNC_END(native_restore_fl)
EXPORT_SYMBOL(native_restore_fl)
diff --git a/arch/x86/kernel/kprobes/core.c b/arch/x86/kernel/kprobes/core.c
index 535da74c124e..ee85f1b258d0 100644
--- a/arch/x86/kernel/kprobes/core.c
+++ b/arch/x86/kernel/kprobes/core.c
@@ -768,7 +768,7 @@ asm(
RESTORE_REGS_STRING
" popfl\n"
#endif
- " ret\n"
+ ASM_RET
".size kretprobe_trampoline, .-kretprobe_trampoline\n"
);
NOKPROBE_SYMBOL(kretprobe_trampoline);
diff --git a/arch/x86/kernel/kvm.c b/arch/x86/kernel/kvm.c
index 971609fb15c5..fe9babe94861 100644
--- a/arch/x86/kernel/kvm.c
+++ b/arch/x86/kernel/kvm.c
@@ -953,7 +953,7 @@ asm(
"movq __per_cpu_offset(,%rdi,8), %rax;"
"cmpb $0, " __stringify(KVM_STEAL_TIME_preempted) "+steal_time(%rax);"
"setne %al;"
-"ret;"
+ASM_RET
".size __raw_callee_save___kvm_vcpu_is_preempted, .-__raw_callee_save___kvm_vcpu_is_preempted;"
".popsection");

diff --git a/arch/x86/kernel/module.c b/arch/x86/kernel/module.c
index 5e9a34b5bd74..455e195847f9 100644
--- a/arch/x86/kernel/module.c
+++ b/arch/x86/kernel/module.c
@@ -251,7 +251,8 @@ int module_finalize(const Elf_Ehdr *hdr,
struct module *me)
{
const Elf_Shdr *s, *text = NULL, *alt = NULL, *locks = NULL,
- *para = NULL, *orc = NULL, *orc_ip = NULL;
+ *para = NULL, *orc = NULL, *orc_ip = NULL,
+ *retpolines = NULL, *returns = NULL;
char *secstrings = (void *)hdr + sechdrs[hdr->e_shstrndx].sh_offset;

for (s = sechdrs; s < sechdrs + hdr->e_shnum; s++) {
@@ -267,8 +268,20 @@ int module_finalize(const Elf_Ehdr *hdr,
orc = s;
if (!strcmp(".orc_unwind_ip", secstrings + s->sh_name))
orc_ip = s;
+ if (!strcmp(".retpoline_sites", secstrings + s->sh_name))
+ retpolines = s;
+ if (!strcmp(".return_sites", secstrings + s->sh_name))
+ returns = s;
}

+ if (retpolines) {
+ void *rseg = (void *)retpolines->sh_addr;
+ apply_retpolines(rseg, rseg + retpolines->sh_size);
+ }
+ if (returns) {
+ void *rseg = (void *)returns->sh_addr;
+ apply_returns(rseg, rseg + returns->sh_size);
+ }
if (alt) {
/* patch .altinstructions */
void *aseg = (void *)alt->sh_addr;
diff --git a/arch/x86/kernel/paravirt.c b/arch/x86/kernel/paravirt.c
index 5e5fcf5c376d..e21937680d1f 100644
--- a/arch/x86/kernel/paravirt.c
+++ b/arch/x86/kernel/paravirt.c
@@ -40,7 +40,7 @@ extern void _paravirt_nop(void);
asm (".pushsection .entry.text, \"ax\"\n"
".global _paravirt_nop\n"
"_paravirt_nop:\n\t"
- "ret\n\t"
+ ASM_RET
".size _paravirt_nop, . - _paravirt_nop\n\t"
".type _paravirt_nop, @function\n\t"
".popsection");
diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c
index 0aa1baf9a3af..a2823682d64e 100644
--- a/arch/x86/kernel/process.c
+++ b/arch/x86/kernel/process.c
@@ -556,7 +556,7 @@ static __always_inline void __speculation_ctrl_update(unsigned long tifp,
}

if (updmsr)
- wrmsrl(MSR_IA32_SPEC_CTRL, msr);
+ write_spec_ctrl_current(msr, false);
}

static unsigned long speculation_ctrl_update_tif(struct task_struct *tsk)
diff --git a/arch/x86/kernel/relocate_kernel_32.S b/arch/x86/kernel/relocate_kernel_32.S
index 94b33885f8d2..82a839885a3c 100644
--- a/arch/x86/kernel/relocate_kernel_32.S
+++ b/arch/x86/kernel/relocate_kernel_32.S
@@ -7,10 +7,12 @@
#include <linux/linkage.h>
#include <asm/page_types.h>
#include <asm/kexec.h>
+#include <asm/nospec-branch.h>
#include <asm/processor-flags.h>

/*
- * Must be relocatable PIC code callable as a C function
+ * Must be relocatable PIC code callable as a C function, in particular
+ * there must be a plain RET and not jump to return thunk.
*/

#define PTR(x) (x << 2)
@@ -91,7 +93,9 @@ SYM_CODE_START_NOALIGN(relocate_kernel)
movl %edi, %eax
addl $(identity_mapped - relocate_kernel), %eax
pushl %eax
+ ANNOTATE_UNRET_SAFE
ret
+ int3
SYM_CODE_END(relocate_kernel)

SYM_CODE_START_LOCAL_NOALIGN(identity_mapped)
@@ -159,12 +163,15 @@ SYM_CODE_START_LOCAL_NOALIGN(identity_mapped)
xorl %edx, %edx
xorl %esi, %esi
xorl %ebp, %ebp
+ ANNOTATE_UNRET_SAFE
ret
+ int3
1:
popl %edx
movl CP_PA_SWAP_PAGE(%edi), %esp
addl $PAGE_SIZE, %esp
2:
+ ANNOTATE_RETPOLINE_SAFE
call *%edx

/* get the re-entry point of the peer system */
@@ -190,7 +197,9 @@ SYM_CODE_START_LOCAL_NOALIGN(identity_mapped)
movl %edi, %eax
addl $(virtual_mapped - relocate_kernel), %eax
pushl %eax
+ ANNOTATE_UNRET_SAFE
ret
+ int3
SYM_CODE_END(identity_mapped)

SYM_CODE_START_LOCAL_NOALIGN(virtual_mapped)
@@ -208,7 +217,9 @@ SYM_CODE_START_LOCAL_NOALIGN(virtual_mapped)
popl %edi
popl %esi
popl %ebx
+ ANNOTATE_UNRET_SAFE
ret
+ int3
SYM_CODE_END(virtual_mapped)

/* Do the copies */
@@ -271,7 +282,9 @@ SYM_CODE_START_LOCAL_NOALIGN(swap_pages)
popl %edi
popl %ebx
popl %ebp
+ ANNOTATE_UNRET_SAFE
ret
+ int3
SYM_CODE_END(swap_pages)

.globl kexec_control_code_size
diff --git a/arch/x86/kernel/relocate_kernel_64.S b/arch/x86/kernel/relocate_kernel_64.S
index a4d9a261425b..d2b7d212caa4 100644
--- a/arch/x86/kernel/relocate_kernel_64.S
+++ b/arch/x86/kernel/relocate_kernel_64.S
@@ -13,7 +13,8 @@
#include <asm/unwind_hints.h>

/*
- * Must be relocatable PIC code callable as a C function
+ * Must be relocatable PIC code callable as a C function, in particular
+ * there must be a plain RET and not jump to return thunk.
*/

#define PTR(x) (x << 3)
@@ -104,7 +105,9 @@ SYM_CODE_START_NOALIGN(relocate_kernel)
/* jump to identity mapped page */
addq $(identity_mapped - relocate_kernel), %r8
pushq %r8
+ ANNOTATE_UNRET_SAFE
ret
+ int3
SYM_CODE_END(relocate_kernel)

SYM_CODE_START_LOCAL_NOALIGN(identity_mapped)
@@ -191,7 +194,9 @@ SYM_CODE_START_LOCAL_NOALIGN(identity_mapped)
xorl %r14d, %r14d
xorl %r15d, %r15d

+ ANNOTATE_UNRET_SAFE
ret
+ int3

1:
popq %rdx
@@ -210,7 +215,9 @@ SYM_CODE_START_LOCAL_NOALIGN(identity_mapped)
call swap_pages
movq $virtual_mapped, %rax
pushq %rax
+ ANNOTATE_UNRET_SAFE
ret
+ int3
SYM_CODE_END(identity_mapped)

SYM_CODE_START_LOCAL_NOALIGN(virtual_mapped)
@@ -231,7 +238,9 @@ SYM_CODE_START_LOCAL_NOALIGN(virtual_mapped)
popq %r12
popq %rbp
popq %rbx
+ ANNOTATE_UNRET_SAFE
ret
+ int3
SYM_CODE_END(virtual_mapped)

/* Do the copies */
@@ -288,7 +297,9 @@ SYM_CODE_START_LOCAL_NOALIGN(swap_pages)
lea PAGE_SIZE(%rax), %rsi
jmp 0b
3:
+ ANNOTATE_UNRET_SAFE
ret
+ int3
SYM_CODE_END(swap_pages)

.globl kexec_control_code_size
diff --git a/arch/x86/kernel/sev-es.c b/arch/x86/kernel/sev-es.c
index c222fab112cb..f441002c2327 100644
--- a/arch/x86/kernel/sev-es.c
+++ b/arch/x86/kernel/sev-es.c
@@ -236,7 +236,7 @@ static enum es_result vc_decode_insn(struct es_em_ctxt *ctxt)
return ES_EXCEPTION;
}

- if (!insn_decode(&ctxt->insn, ctxt->regs, buffer, res))
+ if (!insn_decode_from_regs(&ctxt->insn, ctxt->regs, buffer, res))
return ES_DECODE_FAILED;
} else {
res = vc_fetch_insn_kernel(ctxt, buffer);
diff --git a/arch/x86/kernel/sev_verify_cbit.S b/arch/x86/kernel/sev_verify_cbit.S
index ee04941a6546..3355e27c69eb 100644
--- a/arch/x86/kernel/sev_verify_cbit.S
+++ b/arch/x86/kernel/sev_verify_cbit.S
@@ -85,5 +85,5 @@ SYM_FUNC_START(sev_verify_cbit)
#endif
/* Return page-table pointer */
movq %rdi, %rax
- ret
+ RET
SYM_FUNC_END(sev_verify_cbit)
diff --git a/arch/x86/kernel/static_call.c b/arch/x86/kernel/static_call.c
index ca9a380d9c0b..2973b3fb0ec1 100644
--- a/arch/x86/kernel/static_call.c
+++ b/arch/x86/kernel/static_call.c
@@ -11,7 +11,17 @@ enum insn_type {
RET = 3, /* tramp / site cond-tail-call */
};

-static void __ref __static_call_transform(void *insn, enum insn_type type, void *func)
+/*
+ * ud1 %esp, %ecx - a 3 byte #UD that is unique to trampolines, chosen such
+ * that there is no false-positive trampoline identification while also being a
+ * speculation stop.
+ */
+static const u8 tramp_ud[] = { 0x0f, 0xb9, 0xcc };
+
+static const u8 retinsn[] = { RET_INSN_OPCODE, 0xcc, 0xcc, 0xcc, 0xcc };
+
+static void __ref __static_call_transform(void *insn, enum insn_type type,
+ void *func, bool modinit)
{
int size = CALL_INSN_SIZE;
const void *code;
@@ -30,15 +40,17 @@ static void __ref __static_call_transform(void *insn, enum insn_type type, void
break;

case RET:
- code = text_gen_insn(RET_INSN_OPCODE, insn, func);
- size = RET_INSN_SIZE;
+ if (cpu_feature_enabled(X86_FEATURE_RETHUNK))
+ code = text_gen_insn(JMP32_INSN_OPCODE, insn, &__x86_return_thunk);
+ else
+ code = &retinsn;
break;
}

if (memcmp(insn, code, size) == 0)
return;

- if (unlikely(system_state == SYSTEM_BOOTING))
+ if (system_state == SYSTEM_BOOTING || modinit)
return text_poke_early(insn, code, size);

text_poke_bp(insn, code, size, NULL);
@@ -85,14 +97,42 @@ void arch_static_call_transform(void *site, void *tramp, void *func, bool tail)

if (tramp) {
__static_call_validate(tramp, true);
- __static_call_transform(tramp, __sc_insn(!func, true), func);
+ __static_call_transform(tramp, __sc_insn(!func, true), func, false);
}

if (IS_ENABLED(CONFIG_HAVE_STATIC_CALL_INLINE) && site) {
__static_call_validate(site, tail);
- __static_call_transform(site, __sc_insn(!func, tail), func);
+ __static_call_transform(site, __sc_insn(!func, tail), func, false);
}

mutex_unlock(&text_mutex);
}
EXPORT_SYMBOL_GPL(arch_static_call_transform);
+
+#ifdef CONFIG_RETHUNK
+/*
+ * This is called by apply_returns() to fix up static call trampolines,
+ * specifically ARCH_DEFINE_STATIC_CALL_NULL_TRAMP which is recorded as
+ * having a return trampoline.
+ *
+ * The problem is that static_call() is available before determining
+ * X86_FEATURE_RETHUNK and, by implication, running alternatives.
+ *
+ * This means that __static_call_transform() above can have overwritten the
+ * return trampoline and we now need to fix things up to be consistent.
+ */
+bool __static_call_fixup(void *tramp, u8 op, void *dest)
+{
+ if (memcmp(tramp+5, tramp_ud, 3)) {
+ /* Not a trampoline site, not our problem. */
+ return false;
+ }
+
+ mutex_lock(&text_mutex);
+ if (op == RET_INSN_OPCODE || dest == &__x86_return_thunk)
+ __static_call_transform(tramp, RET, NULL, true);
+ mutex_unlock(&text_mutex);
+
+ return true;
+}
+#endif
diff --git a/arch/x86/kernel/umip.c b/arch/x86/kernel/umip.c
index f6225bf22c02..8032f5f7eef9 100644
--- a/arch/x86/kernel/umip.c
+++ b/arch/x86/kernel/umip.c
@@ -356,7 +356,7 @@ bool fixup_umip_exception(struct pt_regs *regs)
if (!nr_copied)
return false;

- if (!insn_decode(&insn, regs, buf, nr_copied))
+ if (!insn_decode_from_regs(&insn, regs, buf, nr_copied))
return false;

umip_inst = identify_insn(&insn);
diff --git a/arch/x86/kernel/verify_cpu.S b/arch/x86/kernel/verify_cpu.S
index 641f0fe1e5b4..1258a5872d12 100644
--- a/arch/x86/kernel/verify_cpu.S
+++ b/arch/x86/kernel/verify_cpu.S
@@ -132,9 +132,9 @@ SYM_FUNC_START_LOCAL(verify_cpu)
.Lverify_cpu_no_longmode:
popf # Restore caller passed flags
movl $1,%eax
- ret
+ RET
.Lverify_cpu_sse_ok:
popf # Restore caller passed flags
xorl %eax, %eax
- ret
+ RET
SYM_FUNC_END(verify_cpu)
diff --git a/arch/x86/kernel/vmlinux.lds.S b/arch/x86/kernel/vmlinux.lds.S
index bf9e0adb5b7e..a21cd2381fa8 100644
--- a/arch/x86/kernel/vmlinux.lds.S
+++ b/arch/x86/kernel/vmlinux.lds.S
@@ -142,7 +142,7 @@ SECTIONS

#ifdef CONFIG_RETPOLINE
__indirect_thunk_start = .;
- *(.text.__x86.indirect_thunk)
+ *(.text.__x86.*)
__indirect_thunk_end = .;
#endif
} :text =0xcccc
@@ -272,6 +272,27 @@ SECTIONS
__parainstructions_end = .;
}

+#ifdef CONFIG_RETPOLINE
+ /*
+ * List of instructions that call/jmp/jcc to retpoline thunks
+ * __x86_indirect_thunk_*(). These instructions can be patched along
+ * with alternatives, after which the section can be freed.
+ */
+ . = ALIGN(8);
+ .retpoline_sites : AT(ADDR(.retpoline_sites) - LOAD_OFFSET) {
+ __retpoline_sites = .;
+ *(.retpoline_sites)
+ __retpoline_sites_end = .;
+ }
+
+ . = ALIGN(8);
+ .return_sites : AT(ADDR(.return_sites) - LOAD_OFFSET) {
+ __return_sites = .;
+ *(.return_sites)
+ __return_sites_end = .;
+ }
+#endif
+
/*
* struct alt_inst entries. From the header (alternative.h):
* "Alternative instructions for different CPU types or capabilities"
diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c
index 71e1a2d39f21..737035f16a9e 100644
--- a/arch/x86/kvm/emulate.c
+++ b/arch/x86/kvm/emulate.c
@@ -188,9 +188,6 @@
#define X8(x...) X4(x), X4(x)
#define X16(x...) X8(x), X8(x)

-#define NR_FASTOP (ilog2(sizeof(ulong)) + 1)
-#define FASTOP_SIZE 8
-
struct opcode {
u64 flags : 56;
u64 intercept : 8;
@@ -304,9 +301,15 @@ static void invalidate_registers(struct x86_emulate_ctxt *ctxt)
* Moreover, they are all exactly FASTOP_SIZE bytes long, so functions for
* different operand sizes can be reached by calculation, rather than a jump
* table (which would be bigger than the code).
+ *
+ * The 16 byte alignment, considering 5 bytes for the RET thunk, 3 for ENDBR
+ * and 1 for the straight line speculation INT3, leaves 7 bytes for the
+ * body of the function. Currently none is larger than 4.
*/
static int fastop(struct x86_emulate_ctxt *ctxt, fastop_t fop);

+#define FASTOP_SIZE 16
+
#define __FOP_FUNC(name) \
".align " __stringify(FASTOP_SIZE) " \n\t" \
".type " name ", @function \n\t" \
@@ -316,19 +319,21 @@ static int fastop(struct x86_emulate_ctxt *ctxt, fastop_t fop);
__FOP_FUNC(#name)

#define __FOP_RET(name) \
- "ret \n\t" \
+ ASM_RET \
".size " name ", .-" name "\n\t"

#define FOP_RET(name) \
__FOP_RET(#name)

-#define FOP_START(op) \
+#define __FOP_START(op, align) \
extern void em_##op(struct fastop *fake); \
asm(".pushsection .text, \"ax\" \n\t" \
".global em_" #op " \n\t" \
- ".align " __stringify(FASTOP_SIZE) " \n\t" \
+ ".align " __stringify(align) " \n\t" \
"em_" #op ":\n\t"

+#define FOP_START(op) __FOP_START(op, FASTOP_SIZE)
+
#define FOP_END \
".popsection")

@@ -428,19 +433,29 @@ static int fastop(struct x86_emulate_ctxt *ctxt, fastop_t fop);
FOP_END

/* Special case for SETcc - 1 instruction per cc */
+
+/*
+ * Depending on .config the SETcc functions look like:
+ *
+ * SETcc %al [3 bytes]
+ * RET | JMP __x86_return_thunk [1,5 bytes; CONFIG_RETHUNK]
+ * INT3 [1 byte; CONFIG_SLS]
+ */
+#define SETCC_ALIGN 16
+
#define FOP_SETCC(op) \
- ".align 4 \n\t" \
+ ".align " __stringify(SETCC_ALIGN) " \n\t" \
".type " #op ", @function \n\t" \
#op ": \n\t" \
#op " %al \n\t" \
- __FOP_RET(#op)
+ __FOP_RET(#op) \
+ ".skip " __stringify(SETCC_ALIGN) " - (.-" #op "), 0xcc \n\t"

asm(".pushsection .fixup, \"ax\"\n"
- ".global kvm_fastop_exception \n"
- "kvm_fastop_exception: xor %esi, %esi; ret\n"
+ "kvm_fastop_exception: xor %esi, %esi; " ASM_RET
".popsection");

-FOP_START(setcc)
+__FOP_START(setcc, SETCC_ALIGN)
FOP_SETCC(seto)
FOP_SETCC(setno)
FOP_SETCC(setc)
@@ -1055,7 +1070,7 @@ static int em_bsr_c(struct x86_emulate_ctxt *ctxt)
static __always_inline u8 test_cc(unsigned int condition, unsigned long flags)
{
u8 rc;
- void (*fop)(void) = (void *)em_setcc + 4 * (condition & 0xf);
+ void (*fop)(void) = (void *)em_setcc + SETCC_ALIGN * (condition & 0xf);

flags = (flags & EFLAGS_MASK) | X86_EFLAGS_IF;
asm("push %[flags]; popf; " CALL_NOSPEC
diff --git a/arch/x86/kvm/svm/vmenter.S b/arch/x86/kvm/svm/vmenter.S
index 1ec1ac40e328..c18d812d00cd 100644
--- a/arch/x86/kvm/svm/vmenter.S
+++ b/arch/x86/kvm/svm/vmenter.S
@@ -128,6 +128,15 @@ SYM_FUNC_START(__svm_vcpu_run)
mov %r15, VCPU_R15(%_ASM_AX)
#endif

+ /*
+ * Mitigate RETBleed for AMD/Hygon Zen uarch. RET should be
+ * untrained as soon as we exit the VM and are back to the
+ * kernel. This should be done before re-enabling interrupts
+ * because interrupt handlers won't sanitize 'ret' if the return is
+ * from the kernel.
+ */
+ UNTRAIN_RET
+
/*
* Clear all general purpose registers except RSP and RAX to prevent
* speculative use of the guest's values, even those that are reloaded
@@ -166,5 +175,5 @@ SYM_FUNC_START(__svm_vcpu_run)
pop %edi
#endif
pop %_ASM_BP
- ret
+ RET
SYM_FUNC_END(__svm_vcpu_run)
diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c
index 90881d7b42ea..09804cad6e2d 100644
--- a/arch/x86/kvm/vmx/nested.c
+++ b/arch/x86/kvm/vmx/nested.c
@@ -12,6 +12,7 @@
#include "nested.h"
#include "pmu.h"
#include "trace.h"
+#include "vmx.h"
#include "x86.h"

static bool __read_mostly enable_shadow_vmcs = 1;
@@ -3075,35 +3076,8 @@ static int nested_vmx_check_vmentry_hw(struct kvm_vcpu *vcpu)
vmx->loaded_vmcs->host_state.cr4 = cr4;
}

- asm(
- "sub $%c[wordsize], %%" _ASM_SP "\n\t" /* temporarily adjust RSP for CALL */
- "cmp %%" _ASM_SP ", %c[host_state_rsp](%[loaded_vmcs]) \n\t"
- "je 1f \n\t"
- __ex("vmwrite %%" _ASM_SP ", %[HOST_RSP]") "\n\t"
- "mov %%" _ASM_SP ", %c[host_state_rsp](%[loaded_vmcs]) \n\t"
- "1: \n\t"
- "add $%c[wordsize], %%" _ASM_SP "\n\t" /* un-adjust RSP */
-
- /* Check if vmlaunch or vmresume is needed */
- "cmpb $0, %c[launched](%[loaded_vmcs])\n\t"
-
- /*
- * VMLAUNCH and VMRESUME clear RFLAGS.{CF,ZF} on VM-Exit, set
- * RFLAGS.CF on VM-Fail Invalid and set RFLAGS.ZF on VM-Fail
- * Valid. vmx_vmenter() directly "returns" RFLAGS, and so the
- * results of VM-Enter is captured via CC_{SET,OUT} to vm_fail.
- */
- "call vmx_vmenter\n\t"
-
- CC_SET(be)
- : ASM_CALL_CONSTRAINT, CC_OUT(be) (vm_fail)
- : [HOST_RSP]"r"((unsigned long)HOST_RSP),
- [loaded_vmcs]"r"(vmx->loaded_vmcs),
- [launched]"i"(offsetof(struct loaded_vmcs, launched)),
- [host_state_rsp]"i"(offsetof(struct loaded_vmcs, host_state.rsp)),
- [wordsize]"i"(sizeof(ulong))
- : "memory"
- );
+ vm_fail = __vmx_vcpu_run(vmx, (unsigned long *)&vcpu->arch.regs,
+ __vmx_vcpu_run_flags(vmx));

if (vmx->msr_autoload.host.nr)
vmcs_write32(VM_EXIT_MSR_LOAD_COUNT, vmx->msr_autoload.host.nr);
diff --git a/arch/x86/kvm/vmx/run_flags.h b/arch/x86/kvm/vmx/run_flags.h
new file mode 100644
index 000000000000..edc3f16cc189
--- /dev/null
+++ b/arch/x86/kvm/vmx/run_flags.h
@@ -0,0 +1,8 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __KVM_X86_VMX_RUN_FLAGS_H
+#define __KVM_X86_VMX_RUN_FLAGS_H
+
+#define VMX_RUN_VMRESUME (1 << 0)
+#define VMX_RUN_SAVE_SPEC_CTRL (1 << 1)
+
+#endif /* __KVM_X86_VMX_RUN_FLAGS_H */
diff --git a/arch/x86/kvm/vmx/vmenter.S b/arch/x86/kvm/vmx/vmenter.S
index 90ad7a6246e3..857fa0fc49fa 100644
--- a/arch/x86/kvm/vmx/vmenter.S
+++ b/arch/x86/kvm/vmx/vmenter.S
@@ -5,6 +5,7 @@
#include <asm/kvm_vcpu_regs.h>
#include <asm/nospec-branch.h>
#include <asm/segment.h>
+#include "run_flags.h"

#define WORD_SIZE (BITS_PER_LONG / 8)

@@ -30,73 +31,12 @@

.section .noinstr.text, "ax"

-/**
- * vmx_vmenter - VM-Enter the current loaded VMCS
- *
- * %RFLAGS.ZF: !VMCS.LAUNCHED, i.e. controls VMLAUNCH vs. VMRESUME
- *
- * Returns:
- * %RFLAGS.CF is set on VM-Fail Invalid
- * %RFLAGS.ZF is set on VM-Fail Valid
- * %RFLAGS.{CF,ZF} are cleared on VM-Success, i.e. VM-Exit
- *
- * Note that VMRESUME/VMLAUNCH fall-through and return directly if
- * they VM-Fail, whereas a successful VM-Enter + VM-Exit will jump
- * to vmx_vmexit.
- */
-SYM_FUNC_START(vmx_vmenter)
- /* EFLAGS.ZF is set if VMCS.LAUNCHED == 0 */
- je 2f
-
-1: vmresume
- ret
-
-2: vmlaunch
- ret
-
-3: cmpb $0, kvm_rebooting
- je 4f
- ret
-4: ud2
-
- _ASM_EXTABLE(1b, 3b)
- _ASM_EXTABLE(2b, 3b)
-
-SYM_FUNC_END(vmx_vmenter)
-
-/**
- * vmx_vmexit - Handle a VMX VM-Exit
- *
- * Returns:
- * %RFLAGS.{CF,ZF} are cleared on VM-Success, i.e. VM-Exit
- *
- * This is vmx_vmenter's partner in crime. On a VM-Exit, control will jump
- * here after hardware loads the host's state, i.e. this is the destination
- * referred to by VMCS.HOST_RIP.
- */
-SYM_FUNC_START(vmx_vmexit)
-#ifdef CONFIG_RETPOLINE
- ALTERNATIVE "jmp .Lvmexit_skip_rsb", "", X86_FEATURE_RETPOLINE
- /* Preserve guest's RAX, it's used to stuff the RSB. */
- push %_ASM_AX
-
- /* IMPORTANT: Stuff the RSB immediately after VM-Exit, before RET! */
- FILL_RETURN_BUFFER %_ASM_AX, RSB_CLEAR_LOOPS, X86_FEATURE_RETPOLINE
-
- /* Clear RFLAGS.CF and RFLAGS.ZF to preserve VM-Exit, i.e. !VM-Fail. */
- or $1, %_ASM_AX
-
- pop %_ASM_AX
-.Lvmexit_skip_rsb:
-#endif
- ret
-SYM_FUNC_END(vmx_vmexit)
-
/**
* __vmx_vcpu_run - Run a vCPU via a transition to VMX guest mode
- * @vmx: struct vcpu_vmx * (forwarded to vmx_update_host_rsp)
+ * @vmx: struct vcpu_vmx *
* @regs: unsigned long * (to guest registers)
- * @launched: %true if the VMCS has been launched
+ * @flags: VMX_RUN_VMRESUME: use VMRESUME instead of VMLAUNCH
+ * VMX_RUN_SAVE_SPEC_CTRL: save guest SPEC_CTRL into vmx->spec_ctrl
*
* Returns:
* 0 on VM-Exit, 1 on VM-Fail
@@ -115,24 +55,29 @@ SYM_FUNC_START(__vmx_vcpu_run)
#endif
push %_ASM_BX

+ /* Save @vmx for SPEC_CTRL handling */
+ push %_ASM_ARG1
+
+ /* Save @flags for SPEC_CTRL handling */
+ push %_ASM_ARG3
+
/*
* Save @regs, _ASM_ARG2 may be modified by vmx_update_host_rsp() and
* @regs is needed after VM-Exit to save the guest's register values.
*/
push %_ASM_ARG2

- /* Copy @launched to BL, _ASM_ARG3 is volatile. */
+ /* Copy @flags to BL, _ASM_ARG3 is volatile. */
mov %_ASM_ARG3B, %bl

- /* Adjust RSP to account for the CALL to vmx_vmenter(). */
- lea -WORD_SIZE(%_ASM_SP), %_ASM_ARG2
+ lea (%_ASM_SP), %_ASM_ARG2
call vmx_update_host_rsp

/* Load @regs to RAX. */
mov (%_ASM_SP), %_ASM_AX

/* Check if vmlaunch or vmresume is needed */
- cmpb $0, %bl
+ testb $VMX_RUN_VMRESUME, %bl

/* Load guest registers. Don't clobber flags. */
mov VCPU_RCX(%_ASM_AX), %_ASM_CX
@@ -154,11 +99,36 @@ SYM_FUNC_START(__vmx_vcpu_run)
/* Load guest RAX. This kills the @regs pointer! */
mov VCPU_RAX(%_ASM_AX), %_ASM_AX

- /* Enter guest mode */
- call vmx_vmenter
+ /* Check EFLAGS.ZF from 'testb' above */
+ jz .Lvmlaunch
+
+ /*
+ * After a successful VMRESUME/VMLAUNCH, control flow "magically"
+ * resumes below at 'vmx_vmexit' due to the VMCS HOST_RIP setting.
+ * So this isn't a typical function and objtool needs to be told to
+ * save the unwind state here and restore it below.
+ */
+ UNWIND_HINT_SAVE
+
+/*
+ * If VMRESUME/VMLAUNCH and corresponding vmexit succeed, execution resumes at
+ * the 'vmx_vmexit' label below.
+ */
+.Lvmresume:
+ vmresume
+ jmp .Lvmfail
+
+.Lvmlaunch:
+ vmlaunch
+ jmp .Lvmfail
+
+ _ASM_EXTABLE(.Lvmresume, .Lfixup)
+ _ASM_EXTABLE(.Lvmlaunch, .Lfixup)

- /* Jump on VM-Fail. */
- jbe 2f
+SYM_INNER_LABEL(vmx_vmexit, SYM_L_GLOBAL)
+
+ /* Restore unwind state from before the VMRESUME/VMLAUNCH. */
+ UNWIND_HINT_RESTORE

/* Temporarily save guest's RAX. */
push %_ASM_AX
@@ -185,21 +155,23 @@ SYM_FUNC_START(__vmx_vcpu_run)
mov %r15, VCPU_R15(%_ASM_AX)
#endif

- /* Clear RAX to indicate VM-Exit (as opposed to VM-Fail). */
- xor %eax, %eax
+ /* Clear return value to indicate VM-Exit (as opposed to VM-Fail). */
+ xor %ebx, %ebx

+.Lclear_regs:
/*
- * Clear all general purpose registers except RSP and RAX to prevent
+ * Clear all general purpose registers except RSP and RBX to prevent
* speculative use of the guest's values, even those that are reloaded
* via the stack. In theory, an L1 cache miss when restoring registers
* could lead to speculative execution with the guest's values.
* Zeroing XORs are dirt cheap, i.e. the extra paranoia is essentially
* free. RSP and RAX are exempt as RSP is restored by hardware during
- * VM-Exit and RAX is explicitly loaded with 0 or 1 to return VM-Fail.
+ * VM-Exit and RBX is explicitly loaded with 0 or 1 to hold the return
+ * value.
*/
-1: xor %ecx, %ecx
+ xor %eax, %eax
+ xor %ecx, %ecx
xor %edx, %edx
- xor %ebx, %ebx
xor %ebp, %ebp
xor %esi, %esi
xor %edi, %edi
@@ -216,8 +188,30 @@ SYM_FUNC_START(__vmx_vcpu_run)

/* "POP" @regs. */
add $WORD_SIZE, %_ASM_SP
- pop %_ASM_BX

+ /*
+ * IMPORTANT: RSB filling and SPEC_CTRL handling must be done before
+ * the first unbalanced RET after vmexit!
+ *
+ * For retpoline or IBRS, RSB filling is needed to prevent poisoned RSB
+ * entries and (in some cases) RSB underflow.
+ *
+ * eIBRS has its own protection against poisoned RSB, so it doesn't
+ * need the RSB filling sequence. But it does need to be enabled
+ * before the first unbalanced RET.
+ */
+
+ FILL_RETURN_BUFFER %_ASM_CX, RSB_CLEAR_LOOPS, X86_FEATURE_RSB_VMEXIT
+
+ pop %_ASM_ARG2 /* @flags */
+ pop %_ASM_ARG1 /* @vmx */
+
+ call vmx_spec_ctrl_restore_host
+
+ /* Put return value in AX */
+ mov %_ASM_BX, %_ASM_AX
+
+ pop %_ASM_BX
#ifdef CONFIG_X86_64
pop %r12
pop %r13
@@ -228,11 +222,17 @@ SYM_FUNC_START(__vmx_vcpu_run)
pop %edi
#endif
pop %_ASM_BP
- ret
+ RET
+
+.Lfixup:
+ cmpb $0, kvm_rebooting
+ jne .Lvmfail
+ ud2
+.Lvmfail:
+ /* VM-Fail: set return value to 1 */
+ mov $1, %_ASM_BX
+ jmp .Lclear_regs

- /* VM-Fail. Out-of-line to avoid a taken Jcc after VM-Exit. */
-2: mov $1, %eax
- jmp 1b
SYM_FUNC_END(__vmx_vcpu_run)

@@ -293,7 +293,7 @@ SYM_FUNC_START(vmread_error_trampoline)
pop %_ASM_AX
pop %_ASM_BP

- ret
+ RET
SYM_FUNC_END(vmread_error_trampoline)

SYM_FUNC_START(vmx_do_interrupt_nmi_irqoff)
@@ -326,5 +326,5 @@ SYM_FUNC_START(vmx_do_interrupt_nmi_irqoff)
*/
mov %_ASM_BP, %_ASM_SP
pop %_ASM_BP
- ret
+ RET
SYM_FUNC_END(vmx_do_interrupt_nmi_irqoff)
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index cc647dcc228b..9b520da3f748 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -380,9 +380,9 @@ static __always_inline void vmx_disable_fb_clear(struct vcpu_vmx *vmx)
if (!vmx->disable_fb_clear)
return;

- rdmsrl(MSR_IA32_MCU_OPT_CTRL, msr);
+ msr = __rdmsr(MSR_IA32_MCU_OPT_CTRL);
msr |= FB_CLEAR_DIS;
- wrmsrl(MSR_IA32_MCU_OPT_CTRL, msr);
+ native_wrmsrl(MSR_IA32_MCU_OPT_CTRL, msr);
/* Cache the MSR value to avoid reading it later */
vmx->msr_ia32_mcu_opt_ctrl = msr;
}
@@ -393,7 +393,7 @@ static __always_inline void vmx_enable_fb_clear(struct vcpu_vmx *vmx)
return;

vmx->msr_ia32_mcu_opt_ctrl &= ~FB_CLEAR_DIS;
- wrmsrl(MSR_IA32_MCU_OPT_CTRL, vmx->msr_ia32_mcu_opt_ctrl);
+ native_wrmsrl(MSR_IA32_MCU_OPT_CTRL, vmx->msr_ia32_mcu_opt_ctrl);
}

static void vmx_update_fb_clear_dis(struct kvm_vcpu *vcpu, struct vcpu_vmx *vmx)
@@ -936,6 +936,24 @@ static bool msr_write_intercepted(struct vcpu_vmx *vmx, u32 msr)
return true;
}

+unsigned int __vmx_vcpu_run_flags(struct vcpu_vmx *vmx)
+{
+ unsigned int flags = 0;
+
+ if (vmx->loaded_vmcs->launched)
+ flags |= VMX_RUN_VMRESUME;
+
+ /*
+ * If writes to the SPEC_CTRL MSR aren't intercepted, the guest is free
+ * to change it directly without causing a vmexit. In that case read
+ * it after vmexit and store it in vmx->spec_ctrl.
+ */
+ if (unlikely(!msr_write_intercepted(vmx, MSR_IA32_SPEC_CTRL)))
+ flags |= VMX_RUN_SAVE_SPEC_CTRL;
+
+ return flags;
+}
+
static void clear_atomic_switch_msr_special(struct vcpu_vmx *vmx,
unsigned long entry, unsigned long exit)
{
@@ -6675,6 +6693,31 @@ void noinstr vmx_update_host_rsp(struct vcpu_vmx *vmx, unsigned long host_rsp)
}
}

+void noinstr vmx_spec_ctrl_restore_host(struct vcpu_vmx *vmx,
+ unsigned int flags)
+{
+ u64 hostval = this_cpu_read(x86_spec_ctrl_current);
+
+ if (!cpu_feature_enabled(X86_FEATURE_MSR_SPEC_CTRL))
+ return;
+
+ if (flags & VMX_RUN_SAVE_SPEC_CTRL)
+ vmx->spec_ctrl = __rdmsr(MSR_IA32_SPEC_CTRL);
+
+ /*
+ * If the guest/host SPEC_CTRL values differ, restore the host value.
+ *
+ * For legacy IBRS, the IBRS bit always needs to be written after
+ * transitioning from a less privileged predictor mode, regardless of
+ * whether the guest/host values differ.
+ */
+ if (cpu_feature_enabled(X86_FEATURE_KERNEL_IBRS) ||
+ vmx->spec_ctrl != hostval)
+ native_wrmsrl(MSR_IA32_SPEC_CTRL, hostval);
+
+ barrier_nospec();
+}
+
static fastpath_t vmx_exit_handlers_fastpath(struct kvm_vcpu *vcpu)
{
switch (to_vmx(vcpu)->exit_reason.basic) {
@@ -6687,10 +6730,9 @@ static fastpath_t vmx_exit_handlers_fastpath(struct kvm_vcpu *vcpu)
}
}

-bool __vmx_vcpu_run(struct vcpu_vmx *vmx, unsigned long *regs, bool launched);
-
static noinstr void vmx_vcpu_enter_exit(struct kvm_vcpu *vcpu,
- struct vcpu_vmx *vmx)
+ struct vcpu_vmx *vmx,
+ unsigned long flags)
{
/*
* VMENTER enables interrupts (host state), but the kernel state is
@@ -6727,7 +6769,7 @@ static noinstr void vmx_vcpu_enter_exit(struct kvm_vcpu *vcpu,
native_write_cr2(vcpu->arch.cr2);

vmx->fail = __vmx_vcpu_run(vmx, (unsigned long *)&vcpu->arch.regs,
- vmx->loaded_vmcs->launched);
+ flags);

vcpu->arch.cr2 = native_read_cr2();

@@ -6826,27 +6868,7 @@ static fastpath_t vmx_vcpu_run(struct kvm_vcpu *vcpu)
x86_spec_ctrl_set_guest(vmx->spec_ctrl, 0);

/* The actual VMENTER/EXIT is in the .noinstr.text section. */
- vmx_vcpu_enter_exit(vcpu, vmx);
-
- /*
- * We do not use IBRS in the kernel. If this vCPU has used the
- * SPEC_CTRL MSR it may have left it on; save the value and
- * turn it off. This is much more efficient than blindly adding
- * it to the atomic save/restore list. Especially as the former
- * (Saving guest MSRs on vmexit) doesn't even exist in KVM.
- *
- * For non-nested case:
- * If the L01 MSR bitmap does not intercept the MSR, then we need to
- * save it.
- *
- * For nested case:
- * If the L02 MSR bitmap does not intercept the MSR, then we need to
- * save it.
- */
- if (unlikely(!msr_write_intercepted(vmx, MSR_IA32_SPEC_CTRL)))
- vmx->spec_ctrl = native_read_msr(MSR_IA32_SPEC_CTRL);
-
- x86_spec_ctrl_restore_host(vmx->spec_ctrl, 0);
+ vmx_vcpu_enter_exit(vcpu, vmx, __vmx_vcpu_run_flags(vmx));

/* All fields are clean at this point */
if (static_branch_unlikely(&enable_evmcs))
diff --git a/arch/x86/kvm/vmx/vmx.h b/arch/x86/kvm/vmx/vmx.h
index 31317c8915e4..a6b52d3a39c9 100644
--- a/arch/x86/kvm/vmx/vmx.h
+++ b/arch/x86/kvm/vmx/vmx.h
@@ -13,6 +13,7 @@
#include "vmcs.h"
#include "vmx_ops.h"
#include "cpuid.h"
+#include "run_flags.h"

extern const u32 vmx_msr_index[];

@@ -365,6 +366,10 @@ void vmx_set_virtual_apic_mode(struct kvm_vcpu *vcpu);
struct vmx_uret_msr *vmx_find_uret_msr(struct vcpu_vmx *vmx, u32 msr);
void pt_update_intercept_for_msr(struct kvm_vcpu *vcpu);
void vmx_update_host_rsp(struct vcpu_vmx *vmx, unsigned long host_rsp);
+void vmx_spec_ctrl_restore_host(struct vcpu_vmx *vmx, unsigned int flags);
+unsigned int __vmx_vcpu_run_flags(struct vcpu_vmx *vmx);
+bool __vmx_vcpu_run(struct vcpu_vmx *vmx, unsigned long *regs,
+ unsigned int flags);
int vmx_find_loadstore_msr_slot(struct vmx_msrs *m, u32 msr);
void vmx_ept_load_pdptrs(struct kvm_vcpu *vcpu);

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index c71f702c037d..29a8ca95c581 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -11173,9 +11173,9 @@ void kvm_arch_end_assignment(struct kvm *kvm)
}
EXPORT_SYMBOL_GPL(kvm_arch_end_assignment);

-bool kvm_arch_has_assigned_device(struct kvm *kvm)
+bool noinstr kvm_arch_has_assigned_device(struct kvm *kvm)
{
- return atomic_read(&kvm->arch.assigned_device_count);
+ return arch_atomic_read(&kvm->arch.assigned_device_count);
}
EXPORT_SYMBOL_GPL(kvm_arch_has_assigned_device);

diff --git a/arch/x86/lib/atomic64_386_32.S b/arch/x86/lib/atomic64_386_32.S
index 3b6544111ac9..e768815e58ae 100644
--- a/arch/x86/lib/atomic64_386_32.S
+++ b/arch/x86/lib/atomic64_386_32.S
@@ -6,84 +6,86 @@
*/

#include <linux/linkage.h>
-#include <asm/alternative-asm.h>
+#include <asm/alternative.h>

/* if you want SMP support, implement these with real spinlocks */
-.macro LOCK reg
+.macro IRQ_SAVE reg
pushfl
cli
.endm

-.macro UNLOCK reg
+.macro IRQ_RESTORE reg
popfl
.endm

-#define BEGIN(op) \
+#define BEGIN_IRQ_SAVE(op) \
.macro endp; \
SYM_FUNC_END(atomic64_##op##_386); \
.purgem endp; \
.endm; \
SYM_FUNC_START(atomic64_##op##_386); \
- LOCK v;
+ IRQ_SAVE v;

#define ENDP endp

-#define RET \
- UNLOCK v; \
- ret
-
-#define RET_ENDP \
- RET; \
- ENDP
+#define RET_IRQ_RESTORE \
+ IRQ_RESTORE v; \
+ RET

#define v %ecx
-BEGIN(read)
+BEGIN_IRQ_SAVE(read)
movl (v), %eax
movl 4(v), %edx
-RET_ENDP
+ RET_IRQ_RESTORE
+ENDP
#undef v

#define v %esi
-BEGIN(set)
+BEGIN_IRQ_SAVE(set)
movl %ebx, (v)
movl %ecx, 4(v)
-RET_ENDP
+ RET_IRQ_RESTORE
+ENDP
#undef v

#define v %esi
-BEGIN(xchg)
+BEGIN_IRQ_SAVE(xchg)
movl (v), %eax
movl 4(v), %edx
movl %ebx, (v)
movl %ecx, 4(v)
-RET_ENDP
+ RET_IRQ_RESTORE
+ENDP
#undef v

#define v %ecx
-BEGIN(add)
+BEGIN_IRQ_SAVE(add)
addl %eax, (v)
adcl %edx, 4(v)
-RET_ENDP
+ RET_IRQ_RESTORE
+ENDP
#undef v

#define v %ecx
-BEGIN(add_return)
+BEGIN_IRQ_SAVE(add_return)
addl (v), %eax
adcl 4(v), %edx
movl %eax, (v)
movl %edx, 4(v)
-RET_ENDP
+ RET_IRQ_RESTORE
+ENDP
#undef v

#define v %ecx
-BEGIN(sub)
+BEGIN_IRQ_SAVE(sub)
subl %eax, (v)
sbbl %edx, 4(v)
-RET_ENDP
+ RET_IRQ_RESTORE
+ENDP
#undef v

#define v %ecx
-BEGIN(sub_return)
+BEGIN_IRQ_SAVE(sub_return)
negl %edx
negl %eax
sbbl $0, %edx
@@ -91,47 +93,52 @@ BEGIN(sub_return)
adcl 4(v), %edx
movl %eax, (v)
movl %edx, 4(v)
-RET_ENDP
+ RET_IRQ_RESTORE
+ENDP
#undef v

#define v %esi
-BEGIN(inc)
+BEGIN_IRQ_SAVE(inc)
addl $1, (v)
adcl $0, 4(v)
-RET_ENDP
+ RET_IRQ_RESTORE
+ENDP
#undef v

#define v %esi
-BEGIN(inc_return)
+BEGIN_IRQ_SAVE(inc_return)
movl (v), %eax
movl 4(v), %edx
addl $1, %eax
adcl $0, %edx
movl %eax, (v)
movl %edx, 4(v)
-RET_ENDP
+ RET_IRQ_RESTORE
+ENDP
#undef v

#define v %esi
-BEGIN(dec)
+BEGIN_IRQ_SAVE(dec)
subl $1, (v)
sbbl $0, 4(v)
-RET_ENDP
+ RET_IRQ_RESTORE
+ENDP
#undef v

#define v %esi
-BEGIN(dec_return)
+BEGIN_IRQ_SAVE(dec_return)
movl (v), %eax
movl 4(v), %edx
subl $1, %eax
sbbl $0, %edx
movl %eax, (v)
movl %edx, 4(v)
-RET_ENDP
+ RET_IRQ_RESTORE
+ENDP
#undef v

#define v %esi
-BEGIN(add_unless)
+BEGIN_IRQ_SAVE(add_unless)
addl %eax, %ecx
adcl %edx, %edi
addl (v), %eax
@@ -143,7 +150,7 @@ BEGIN(add_unless)
movl %edx, 4(v)
movl $1, %eax
2:
- RET
+ RET_IRQ_RESTORE
3:
cmpl %edx, %edi
jne 1b
@@ -153,7 +160,7 @@ ENDP
#undef v

#define v %esi
-BEGIN(inc_not_zero)
+BEGIN_IRQ_SAVE(inc_not_zero)
movl (v), %eax
movl 4(v), %edx
testl %eax, %eax
@@ -165,7 +172,7 @@ BEGIN(inc_not_zero)
movl %edx, 4(v)
movl $1, %eax
2:
- RET
+ RET_IRQ_RESTORE
3:
testl %edx, %edx
jne 1b
@@ -174,7 +181,7 @@ ENDP
#undef v

#define v %esi
-BEGIN(dec_if_positive)
+BEGIN_IRQ_SAVE(dec_if_positive)
movl (v), %eax
movl 4(v), %edx
subl $1, %eax
@@ -183,5 +190,6 @@ BEGIN(dec_if_positive)
movl %eax, (v)
movl %edx, 4(v)
1:
-RET_ENDP
+ RET_IRQ_RESTORE
+ENDP
#undef v
diff --git a/arch/x86/lib/atomic64_cx8_32.S b/arch/x86/lib/atomic64_cx8_32.S
index 1c5c81c16b06..90afb488b396 100644
--- a/arch/x86/lib/atomic64_cx8_32.S
+++ b/arch/x86/lib/atomic64_cx8_32.S
@@ -6,7 +6,7 @@
*/

#include <linux/linkage.h>
-#include <asm/alternative-asm.h>
+#include <asm/alternative.h>

.macro read64 reg
movl %ebx, %eax
@@ -18,7 +18,7 @@

SYM_FUNC_START(atomic64_read_cx8)
read64 %ecx
- ret
+ RET
SYM_FUNC_END(atomic64_read_cx8)

SYM_FUNC_START(atomic64_set_cx8)
@@ -28,7 +28,7 @@ SYM_FUNC_START(atomic64_set_cx8)
cmpxchg8b (%esi)
jne 1b

- ret
+ RET
SYM_FUNC_END(atomic64_set_cx8)

SYM_FUNC_START(atomic64_xchg_cx8)
@@ -37,7 +37,7 @@ SYM_FUNC_START(atomic64_xchg_cx8)
cmpxchg8b (%esi)
jne 1b

- ret
+ RET
SYM_FUNC_END(atomic64_xchg_cx8)

.macro addsub_return func ins insc
@@ -68,7 +68,7 @@ SYM_FUNC_START(atomic64_\func\()_return_cx8)
popl %esi
popl %ebx
popl %ebp
- ret
+ RET
SYM_FUNC_END(atomic64_\func\()_return_cx8)
.endm

@@ -93,7 +93,7 @@ SYM_FUNC_START(atomic64_\func\()_return_cx8)
movl %ebx, %eax
movl %ecx, %edx
popl %ebx
- ret
+ RET
SYM_FUNC_END(atomic64_\func\()_return_cx8)
.endm

@@ -118,7 +118,7 @@ SYM_FUNC_START(atomic64_dec_if_positive_cx8)
movl %ebx, %eax
movl %ecx, %edx
popl %ebx
- ret
+ RET
SYM_FUNC_END(atomic64_dec_if_positive_cx8)

SYM_FUNC_START(atomic64_add_unless_cx8)
@@ -149,7 +149,7 @@ SYM_FUNC_START(atomic64_add_unless_cx8)
addl $8, %esp
popl %ebx
popl %ebp
- ret
+ RET
4:
cmpl %edx, 4(%esp)
jne 2b
@@ -176,5 +176,5 @@ SYM_FUNC_START(atomic64_inc_not_zero_cx8)
movl $1, %eax
3:
popl %ebx
- ret
+ RET
SYM_FUNC_END(atomic64_inc_not_zero_cx8)
diff --git a/arch/x86/lib/checksum_32.S b/arch/x86/lib/checksum_32.S
index 4304320e51f4..929ad1747dea 100644
--- a/arch/x86/lib/checksum_32.S
+++ b/arch/x86/lib/checksum_32.S
@@ -127,7 +127,7 @@ SYM_FUNC_START(csum_partial)
8:
popl %ebx
popl %esi
- ret
+ RET
SYM_FUNC_END(csum_partial)

#else
@@ -245,7 +245,7 @@ SYM_FUNC_START(csum_partial)
90:
popl %ebx
popl %esi
- ret
+ RET
SYM_FUNC_END(csum_partial)

#endif
@@ -371,7 +371,7 @@ EXC( movb %cl, (%edi) )
popl %esi
popl %edi
popl %ecx # equivalent to addl $4,%esp
- ret
+ RET
SYM_FUNC_END(csum_partial_copy_generic)

#else
@@ -447,7 +447,7 @@ EXC( movb %dl, (%edi) )
popl %esi
popl %edi
popl %ebx
- ret
+ RET
SYM_FUNC_END(csum_partial_copy_generic)

#undef ROUND
diff --git a/arch/x86/lib/clear_page_64.S b/arch/x86/lib/clear_page_64.S
index c4c7dd115953..fe59b8ac4fcc 100644
--- a/arch/x86/lib/clear_page_64.S
+++ b/arch/x86/lib/clear_page_64.S
@@ -17,7 +17,7 @@ SYM_FUNC_START(clear_page_rep)
movl $4096/8,%ecx
xorl %eax,%eax
rep stosq
- ret
+ RET
SYM_FUNC_END(clear_page_rep)
EXPORT_SYMBOL_GPL(clear_page_rep)

@@ -39,7 +39,7 @@ SYM_FUNC_START(clear_page_orig)
leaq 64(%rdi),%rdi
jnz .Lloop
nop
- ret
+ RET
SYM_FUNC_END(clear_page_orig)
EXPORT_SYMBOL_GPL(clear_page_orig)

@@ -47,6 +47,6 @@ SYM_FUNC_START(clear_page_erms)
movl $4096,%ecx
xorl %eax,%eax
rep stosb
- ret
+ RET
SYM_FUNC_END(clear_page_erms)
EXPORT_SYMBOL_GPL(clear_page_erms)
diff --git a/arch/x86/lib/cmpxchg16b_emu.S b/arch/x86/lib/cmpxchg16b_emu.S
index 3542502faa3b..33c70c0160ea 100644
--- a/arch/x86/lib/cmpxchg16b_emu.S
+++ b/arch/x86/lib/cmpxchg16b_emu.S
@@ -37,11 +37,11 @@ SYM_FUNC_START(this_cpu_cmpxchg16b_emu)

popfq
mov $1, %al
- ret
+ RET

.Lnot_same:
popfq
xor %al,%al
- ret
+ RET

SYM_FUNC_END(this_cpu_cmpxchg16b_emu)
diff --git a/arch/x86/lib/cmpxchg8b_emu.S b/arch/x86/lib/cmpxchg8b_emu.S
index ca01ed6029f4..6a912d58fecc 100644
--- a/arch/x86/lib/cmpxchg8b_emu.S
+++ b/arch/x86/lib/cmpxchg8b_emu.S
@@ -32,7 +32,7 @@ SYM_FUNC_START(cmpxchg8b_emu)
movl %ecx, 4(%esi)

popfl
- ret
+ RET

.Lnot_same:
movl (%esi), %eax
@@ -40,7 +40,7 @@ SYM_FUNC_START(cmpxchg8b_emu)
movl 4(%esi), %edx

popfl
- ret
+ RET

SYM_FUNC_END(cmpxchg8b_emu)
EXPORT_SYMBOL(cmpxchg8b_emu)
diff --git a/arch/x86/lib/copy_mc_64.S b/arch/x86/lib/copy_mc_64.S
index 892d8915f609..fdd1929b1f9d 100644
--- a/arch/x86/lib/copy_mc_64.S
+++ b/arch/x86/lib/copy_mc_64.S
@@ -86,7 +86,7 @@ SYM_FUNC_START(copy_mc_fragile)
.L_done_memcpy_trap:
xorl %eax, %eax
.L_done:
- ret
+ RET
SYM_FUNC_END(copy_mc_fragile)
EXPORT_SYMBOL_GPL(copy_mc_fragile)

@@ -142,7 +142,7 @@ SYM_FUNC_START(copy_mc_enhanced_fast_string)
rep movsb
/* Copy successful. Return zero */
xorl %eax, %eax
- ret
+ RET
SYM_FUNC_END(copy_mc_enhanced_fast_string)

.section .fixup, "ax"
@@ -155,7 +155,7 @@ SYM_FUNC_END(copy_mc_enhanced_fast_string)
* user-copy routines.
*/
movq %rcx, %rax
- ret
+ RET

.previous

diff --git a/arch/x86/lib/copy_page_64.S b/arch/x86/lib/copy_page_64.S
index 2402d4c489d2..30ea644bf446 100644
--- a/arch/x86/lib/copy_page_64.S
+++ b/arch/x86/lib/copy_page_64.S
@@ -3,7 +3,7 @@

#include <linux/linkage.h>
#include <asm/cpufeatures.h>
-#include <asm/alternative-asm.h>
+#include <asm/alternative.h>
#include <asm/export.h>

/*
@@ -17,7 +17,7 @@ SYM_FUNC_START(copy_page)
ALTERNATIVE "jmp copy_page_regs", "", X86_FEATURE_REP_GOOD
movl $4096/8, %ecx
rep movsq
- ret
+ RET
SYM_FUNC_END(copy_page)
EXPORT_SYMBOL(copy_page)

@@ -85,5 +85,5 @@ SYM_FUNC_START_LOCAL(copy_page_regs)
movq (%rsp), %rbx
movq 1*8(%rsp), %r12
addq $2*8, %rsp
- ret
+ RET
SYM_FUNC_END(copy_page_regs)
diff --git a/arch/x86/lib/copy_user_64.S b/arch/x86/lib/copy_user_64.S
index 77b9b2a3b5c8..84cee84fc658 100644
--- a/arch/x86/lib/copy_user_64.S
+++ b/arch/x86/lib/copy_user_64.S
@@ -11,7 +11,7 @@
#include <asm/asm-offsets.h>
#include <asm/thread_info.h>
#include <asm/cpufeatures.h>
-#include <asm/alternative-asm.h>
+#include <asm/alternative.h>
#include <asm/asm.h>
#include <asm/smap.h>
#include <asm/export.h>
@@ -105,7 +105,7 @@ SYM_FUNC_START(copy_user_generic_unrolled)
jnz 21b
23: xor %eax,%eax
ASM_CLAC
- ret
+ RET

.section .fixup,"ax"
30: shll $6,%ecx
@@ -173,7 +173,7 @@ SYM_FUNC_START(copy_user_generic_string)
movsb
xorl %eax,%eax
ASM_CLAC
- ret
+ RET

.section .fixup,"ax"
11: leal (%rdx,%rcx,8),%ecx
@@ -207,7 +207,7 @@ SYM_FUNC_START(copy_user_enhanced_fast_string)
movsb
xorl %eax,%eax
ASM_CLAC
- ret
+ RET

.section .fixup,"ax"
12: movl %ecx,%edx /* ecx is zerorest also */
@@ -239,7 +239,7 @@ SYM_CODE_START_LOCAL(.Lcopy_user_handle_tail)
1: rep movsb
2: mov %ecx,%eax
ASM_CLAC
- ret
+ RET

/*
* Return zero to pretend that this copy succeeded. This
@@ -250,7 +250,7 @@ SYM_CODE_START_LOCAL(.Lcopy_user_handle_tail)
*/
3: xorl %eax,%eax
ASM_CLAC
- ret
+ RET

_ASM_EXTABLE_CPY(1b, 2b)
SYM_CODE_END(.Lcopy_user_handle_tail)
@@ -361,7 +361,7 @@ SYM_FUNC_START(__copy_user_nocache)
xorl %eax,%eax
ASM_CLAC
sfence
- ret
+ RET

.section .fixup,"ax"
.L_fixup_4x8b_copy:
diff --git a/arch/x86/lib/csum-copy_64.S b/arch/x86/lib/csum-copy_64.S
index 1fbd8ee9642d..d9e16a2cf285 100644
--- a/arch/x86/lib/csum-copy_64.S
+++ b/arch/x86/lib/csum-copy_64.S
@@ -201,7 +201,7 @@ SYM_FUNC_START(csum_partial_copy_generic)
movq 3*8(%rsp), %r13
movq 4*8(%rsp), %r15
addq $5*8, %rsp
- ret
+ RET
.Lshort:
movl %ecx, %r10d
jmp .L1
diff --git a/arch/x86/lib/error-inject.c b/arch/x86/lib/error-inject.c
index be5b5fb1598b..520897061ee0 100644
--- a/arch/x86/lib/error-inject.c
+++ b/arch/x86/lib/error-inject.c
@@ -1,5 +1,6 @@
// SPDX-License-Identifier: GPL-2.0

+#include <linux/linkage.h>
#include <linux/error-injection.h>
#include <linux/kprobes.h>

@@ -10,7 +11,7 @@ asm(
".type just_return_func, @function\n"
".globl just_return_func\n"
"just_return_func:\n"
- " ret\n"
+ ASM_RET
".size just_return_func, .-just_return_func\n"
);

diff --git a/arch/x86/lib/getuser.S b/arch/x86/lib/getuser.S
index fa1bc2104b32..b70d98d79a9d 100644
--- a/arch/x86/lib/getuser.S
+++ b/arch/x86/lib/getuser.S
@@ -57,7 +57,7 @@ SYM_FUNC_START(__get_user_1)
1: movzbl (%_ASM_AX),%edx
xor %eax,%eax
ASM_CLAC
- ret
+ RET
SYM_FUNC_END(__get_user_1)
EXPORT_SYMBOL(__get_user_1)

@@ -71,7 +71,7 @@ SYM_FUNC_START(__get_user_2)
2: movzwl (%_ASM_AX),%edx
xor %eax,%eax
ASM_CLAC
- ret
+ RET
SYM_FUNC_END(__get_user_2)
EXPORT_SYMBOL(__get_user_2)

@@ -85,7 +85,7 @@ SYM_FUNC_START(__get_user_4)
3: movl (%_ASM_AX),%edx
xor %eax,%eax
ASM_CLAC
- ret
+ RET
SYM_FUNC_END(__get_user_4)
EXPORT_SYMBOL(__get_user_4)

@@ -100,7 +100,7 @@ SYM_FUNC_START(__get_user_8)
4: movq (%_ASM_AX),%rdx
xor %eax,%eax
ASM_CLAC
- ret
+ RET
#else
LOAD_TASK_SIZE_MINUS_N(7)
cmp %_ASM_DX,%_ASM_AX
@@ -112,7 +112,7 @@ SYM_FUNC_START(__get_user_8)
5: movl 4(%_ASM_AX),%ecx
xor %eax,%eax
ASM_CLAC
- ret
+ RET
#endif
SYM_FUNC_END(__get_user_8)
EXPORT_SYMBOL(__get_user_8)
@@ -124,7 +124,7 @@ SYM_FUNC_START(__get_user_nocheck_1)
6: movzbl (%_ASM_AX),%edx
xor %eax,%eax
ASM_CLAC
- ret
+ RET
SYM_FUNC_END(__get_user_nocheck_1)
EXPORT_SYMBOL(__get_user_nocheck_1)

@@ -134,7 +134,7 @@ SYM_FUNC_START(__get_user_nocheck_2)
7: movzwl (%_ASM_AX),%edx
xor %eax,%eax
ASM_CLAC
- ret
+ RET
SYM_FUNC_END(__get_user_nocheck_2)
EXPORT_SYMBOL(__get_user_nocheck_2)

@@ -144,7 +144,7 @@ SYM_FUNC_START(__get_user_nocheck_4)
8: movl (%_ASM_AX),%edx
xor %eax,%eax
ASM_CLAC
- ret
+ RET
SYM_FUNC_END(__get_user_nocheck_4)
EXPORT_SYMBOL(__get_user_nocheck_4)

@@ -159,7 +159,7 @@ SYM_FUNC_START(__get_user_nocheck_8)
#endif
xor %eax,%eax
ASM_CLAC
- ret
+ RET
SYM_FUNC_END(__get_user_nocheck_8)
EXPORT_SYMBOL(__get_user_nocheck_8)

@@ -169,7 +169,7 @@ SYM_CODE_START_LOCAL(.Lbad_get_user_clac)
bad_get_user:
xor %edx,%edx
mov $(-EFAULT),%_ASM_AX
- ret
+ RET
SYM_CODE_END(.Lbad_get_user_clac)

#ifdef CONFIG_X86_32
@@ -179,7 +179,7 @@ bad_get_user_8:
xor %edx,%edx
xor %ecx,%ecx
mov $(-EFAULT),%_ASM_AX
- ret
+ RET
SYM_CODE_END(.Lbad_get_user_8_clac)
#endif

diff --git a/arch/x86/lib/hweight.S b/arch/x86/lib/hweight.S
index dbf8cc97b7f5..12c16c6aa44a 100644
--- a/arch/x86/lib/hweight.S
+++ b/arch/x86/lib/hweight.S
@@ -32,7 +32,7 @@ SYM_FUNC_START(__sw_hweight32)
imull $0x01010101, %eax, %eax # w_tmp *= 0x01010101
shrl $24, %eax # w = w_tmp >> 24
__ASM_SIZE(pop,) %__ASM_REG(dx)
- ret
+ RET
SYM_FUNC_END(__sw_hweight32)
EXPORT_SYMBOL(__sw_hweight32)

@@ -65,7 +65,7 @@ SYM_FUNC_START(__sw_hweight64)

popq %rdx
popq %rdi
- ret
+ RET
#else /* CONFIG_X86_32 */
/* We're getting an u64 arg in (%eax,%edx): unsigned long hweight64(__u64 w) */
pushl %ecx
@@ -77,7 +77,7 @@ SYM_FUNC_START(__sw_hweight64)
addl %ecx, %eax # result

popl %ecx
- ret
+ RET
#endif
SYM_FUNC_END(__sw_hweight64)
EXPORT_SYMBOL(__sw_hweight64)
diff --git a/arch/x86/lib/inat.c b/arch/x86/lib/inat.c
index 12539fca75c4..b0f3b2a62ae2 100644
--- a/arch/x86/lib/inat.c
+++ b/arch/x86/lib/inat.c
@@ -4,7 +4,7 @@
*
* Written by Masami Hiramatsu <mhiramat@redhat.com>
*/
-#include <asm/insn.h>
+#include <asm/insn.h> /* __ignore_sync_check__ */

/* Attribute tables are generated from opcode map */
#include "inat-tables.c"
diff --git a/arch/x86/lib/insn-eval.c b/arch/x86/lib/insn-eval.c
index c6a19c88af54..ffc8b7dcf1fe 100644
--- a/arch/x86/lib/insn-eval.c
+++ b/arch/x86/lib/insn-eval.c
@@ -928,10 +928,11 @@ static int get_seg_base_limit(struct insn *insn, struct pt_regs *regs,
static int get_eff_addr_reg(struct insn *insn, struct pt_regs *regs,
int *regoff, long *eff_addr)
{
- insn_get_modrm(insn);
+ int ret;

- if (!insn->modrm.nbytes)
- return -EINVAL;
+ ret = insn_get_modrm(insn);
+ if (ret)
+ return ret;

if (X86_MODRM_MOD(insn->modrm.value) != 3)
return -EINVAL;
@@ -977,14 +978,14 @@ static int get_eff_addr_modrm(struct insn *insn, struct pt_regs *regs,
int *regoff, long *eff_addr)
{
long tmp;
+ int ret;

if (insn->addr_bytes != 8 && insn->addr_bytes != 4)
return -EINVAL;

- insn_get_modrm(insn);
-
- if (!insn->modrm.nbytes)
- return -EINVAL;
+ ret = insn_get_modrm(insn);
+ if (ret)
+ return ret;

if (X86_MODRM_MOD(insn->modrm.value) > 2)
return -EINVAL;
@@ -1106,18 +1107,21 @@ static int get_eff_addr_modrm_16(struct insn *insn, struct pt_regs *regs,
* @base_offset will have a register, as an offset from the base of pt_regs,
* that can be used to resolve the associated segment.
*
- * -EINVAL on error.
+ * Negative value on error.
*/
static int get_eff_addr_sib(struct insn *insn, struct pt_regs *regs,
int *base_offset, long *eff_addr)
{
long base, indx;
int indx_offset;
+ int ret;

if (insn->addr_bytes != 8 && insn->addr_bytes != 4)
return -EINVAL;

- insn_get_modrm(insn);
+ ret = insn_get_modrm(insn);
+ if (ret)
+ return ret;

if (!insn->modrm.nbytes)
return -EINVAL;
@@ -1125,7 +1129,9 @@ static int get_eff_addr_sib(struct insn *insn, struct pt_regs *regs,
if (X86_MODRM_MOD(insn->modrm.value) > 2)
return -EINVAL;

- insn_get_sib(insn);
+ ret = insn_get_sib(insn);
+ if (ret)
+ return ret;

if (!insn->sib.nbytes)
return -EINVAL;
@@ -1194,8 +1200,8 @@ static void __user *get_addr_ref_16(struct insn *insn, struct pt_regs *regs)
short eff_addr;
long tmp;

- insn_get_modrm(insn);
- insn_get_displacement(insn);
+ if (insn_get_displacement(insn))
+ goto out;

if (insn->addr_bytes != 2)
goto out;
@@ -1492,7 +1498,7 @@ int insn_fetch_from_user_inatomic(struct pt_regs *regs, unsigned char buf[MAX_IN
}

/**
- * insn_decode() - Decode an instruction
+ * insn_decode_from_regs() - Decode an instruction
* @insn: Structure to store decoded instruction
* @regs: Structure with register values as seen when entering kernel mode
* @buf: Buffer containing the instruction bytes
@@ -1505,8 +1511,8 @@ int insn_fetch_from_user_inatomic(struct pt_regs *regs, unsigned char buf[MAX_IN
*
* True if instruction was decoded, False otherwise.
*/
-bool insn_decode(struct insn *insn, struct pt_regs *regs,
- unsigned char buf[MAX_INSN_SIZE], int buf_size)
+bool insn_decode_from_regs(struct insn *insn, struct pt_regs *regs,
+ unsigned char buf[MAX_INSN_SIZE], int buf_size)
{
int seg_defs;

@@ -1529,7 +1535,9 @@ bool insn_decode(struct insn *insn, struct pt_regs *regs,
insn->addr_bytes = INSN_CODE_SEG_ADDR_SZ(seg_defs);
insn->opnd_bytes = INSN_CODE_SEG_OPND_SZ(seg_defs);

- insn_get_length(insn);
+ if (insn_get_length(insn))
+ return false;
+
if (buf_size < insn->length)
return false;

diff --git a/arch/x86/lib/insn.c b/arch/x86/lib/insn.c
index 404279563891..24e89239dcca 100644
--- a/arch/x86/lib/insn.c
+++ b/arch/x86/lib/insn.c
@@ -10,10 +10,13 @@
#else
#include <string.h>
#endif
-#include <asm/inat.h>
-#include <asm/insn.h>
+#include <asm/inat.h> /*__ignore_sync_check__ */
+#include <asm/insn.h> /* __ignore_sync_check__ */

-#include <asm/emulate_prefix.h>
+#include <linux/errno.h>
+#include <linux/kconfig.h>
+
+#include <asm/emulate_prefix.h> /* __ignore_sync_check__ */

/* Verify next sizeof(t) bytes can be on the same instruction */
#define validate_next(t, insn, n) \
@@ -97,8 +100,12 @@ static void insn_get_emulate_prefix(struct insn *insn)
* Populates the @insn->prefixes bitmap, and updates @insn->next_byte
* to point to the (first) opcode. No effect if @insn->prefixes.got
* is already set.
+ *
+ * * Returns:
+ * 0: on success
+ * < 0: on error
*/
-void insn_get_prefixes(struct insn *insn)
+int insn_get_prefixes(struct insn *insn)
{
struct insn_field *prefixes = &insn->prefixes;
insn_attr_t attr;
@@ -106,7 +113,7 @@ void insn_get_prefixes(struct insn *insn)
int i, nb;

if (prefixes->got)
- return;
+ return 0;

insn_get_emulate_prefix(insn);

@@ -217,8 +224,10 @@ void insn_get_prefixes(struct insn *insn)

prefixes->got = 1;

+ return 0;
+
err_out:
- return;
+ return -ENODATA;
}

/**
@@ -230,16 +239,25 @@ void insn_get_prefixes(struct insn *insn)
* If necessary, first collects any preceding (prefix) bytes.
* Sets @insn->opcode.value = opcode1. No effect if @insn->opcode.got
* is already 1.
+ *
+ * Returns:
+ * 0: on success
+ * < 0: on error
*/
-void insn_get_opcode(struct insn *insn)
+int insn_get_opcode(struct insn *insn)
{
struct insn_field *opcode = &insn->opcode;
+ int pfx_id, ret;
insn_byte_t op;
- int pfx_id;
+
if (opcode->got)
- return;
- if (!insn->prefixes.got)
- insn_get_prefixes(insn);
+ return 0;
+
+ if (!insn->prefixes.got) {
+ ret = insn_get_prefixes(insn);
+ if (ret)
+ return ret;
+ }

/* Get first opcode */
op = get_next(insn_byte_t, insn);
@@ -254,9 +272,13 @@ void insn_get_opcode(struct insn *insn)
insn->attr = inat_get_avx_attribute(op, m, p);
if ((inat_must_evex(insn->attr) && !insn_is_evex(insn)) ||
(!inat_accept_vex(insn->attr) &&
- !inat_is_group(insn->attr)))
- insn->attr = 0; /* This instruction is bad */
- goto end; /* VEX has only 1 byte for opcode */
+ !inat_is_group(insn->attr))) {
+ /* This instruction is bad */
+ insn->attr = 0;
+ return -EINVAL;
+ }
+ /* VEX has only 1 byte for opcode */
+ goto end;
}

insn->attr = inat_get_opcode_attribute(op);
@@ -267,13 +289,18 @@ void insn_get_opcode(struct insn *insn)
pfx_id = insn_last_prefix_id(insn);
insn->attr = inat_get_escape_attribute(op, pfx_id, insn->attr);
}
- if (inat_must_vex(insn->attr))
- insn->attr = 0; /* This instruction is bad */
+
+ if (inat_must_vex(insn->attr)) {
+ /* This instruction is bad */
+ insn->attr = 0;
+ return -EINVAL;
+ }
end:
opcode->got = 1;
+ return 0;

err_out:
- return;
+ return -ENODATA;
}

/**
@@ -283,15 +310,25 @@ void insn_get_opcode(struct insn *insn)
* Populates @insn->modrm and updates @insn->next_byte to point past the
* ModRM byte, if any. If necessary, first collects the preceding bytes
* (prefixes and opcode(s)). No effect if @insn->modrm.got is already 1.
+ *
+ * Returns:
+ * 0: on success
+ * < 0: on error
*/
-void insn_get_modrm(struct insn *insn)
+int insn_get_modrm(struct insn *insn)
{
struct insn_field *modrm = &insn->modrm;
insn_byte_t pfx_id, mod;
+ int ret;
+
if (modrm->got)
- return;
- if (!insn->opcode.got)
- insn_get_opcode(insn);
+ return 0;
+
+ if (!insn->opcode.got) {
+ ret = insn_get_opcode(insn);
+ if (ret)
+ return ret;
+ }

if (inat_has_modrm(insn->attr)) {
mod = get_next(insn_byte_t, insn);
@@ -301,17 +338,22 @@ void insn_get_modrm(struct insn *insn)
pfx_id = insn_last_prefix_id(insn);
insn->attr = inat_get_group_attribute(mod, pfx_id,
insn->attr);
- if (insn_is_avx(insn) && !inat_accept_vex(insn->attr))
- insn->attr = 0; /* This is bad */
+ if (insn_is_avx(insn) && !inat_accept_vex(insn->attr)) {
+ /* Bad insn */
+ insn->attr = 0;
+ return -EINVAL;
+ }
}
}

if (insn->x86_64 && inat_is_force64(insn->attr))
insn->opnd_bytes = 8;
+
modrm->got = 1;
+ return 0;

err_out:
- return;
+ return -ENODATA;
}

@@ -325,11 +367,16 @@ void insn_get_modrm(struct insn *insn)
int insn_rip_relative(struct insn *insn)
{
struct insn_field *modrm = &insn->modrm;
+ int ret;

if (!insn->x86_64)
return 0;
- if (!modrm->got)
- insn_get_modrm(insn);
+
+ if (!modrm->got) {
+ ret = insn_get_modrm(insn);
+ if (ret)
+ return 0;
+ }
/*
* For rip-relative instructions, the mod field (top 2 bits)
* is zero and the r/m field (bottom 3 bits) is 0x5.
@@ -343,15 +390,25 @@ int insn_rip_relative(struct insn *insn)
*
* If necessary, first collects the instruction up to and including the
* ModRM byte.
+ *
+ * Returns:
+ * 0: if decoding succeeded
+ * < 0: otherwise.
*/
-void insn_get_sib(struct insn *insn)
+int insn_get_sib(struct insn *insn)
{
insn_byte_t modrm;
+ int ret;

if (insn->sib.got)
- return;
- if (!insn->modrm.got)
- insn_get_modrm(insn);
+ return 0;
+
+ if (!insn->modrm.got) {
+ ret = insn_get_modrm(insn);
+ if (ret)
+ return ret;
+ }
+
if (insn->modrm.nbytes) {
modrm = (insn_byte_t)insn->modrm.value;
if (insn->addr_bytes != 2 &&
@@ -362,8 +419,10 @@ void insn_get_sib(struct insn *insn)
}
insn->sib.got = 1;

+ return 0;
+
err_out:
- return;
+ return -ENODATA;
}

@@ -374,15 +433,25 @@ void insn_get_sib(struct insn *insn)
* If necessary, first collects the instruction up to and including the
* SIB byte.
* Displacement value is sign-expanded.
+ *
+ * * Returns:
+ * 0: if decoding succeeded
+ * < 0: otherwise.
*/
-void insn_get_displacement(struct insn *insn)
+int insn_get_displacement(struct insn *insn)
{
insn_byte_t mod, rm, base;
+ int ret;

if (insn->displacement.got)
- return;
- if (!insn->sib.got)
- insn_get_sib(insn);
+ return 0;
+
+ if (!insn->sib.got) {
+ ret = insn_get_sib(insn);
+ if (ret)
+ return ret;
+ }
+
if (insn->modrm.nbytes) {
/*
* Interpreting the modrm byte:
@@ -425,9 +494,10 @@ void insn_get_displacement(struct insn *insn)
}
out:
insn->displacement.got = 1;
+ return 0;

err_out:
- return;
+ return -ENODATA;
}

/* Decode moffset16/32/64. Return 0 if failed */
@@ -538,20 +608,30 @@ static int __get_immptr(struct insn *insn)
}

/**
- * insn_get_immediate() - Get the immediates of instruction
+ * insn_get_immediate() - Get the immediate in an instruction
* @insn: &struct insn containing instruction
*
* If necessary, first collects the instruction up to and including the
* displacement bytes.
* Basically, most of immediates are sign-expanded. Unsigned-value can be
- * get by bit masking with ((1 << (nbytes * 8)) - 1)
+ * computed by bit masking with ((1 << (nbytes * 8)) - 1)
+ *
+ * Returns:
+ * 0: on success
+ * < 0: on error
*/
-void insn_get_immediate(struct insn *insn)
+int insn_get_immediate(struct insn *insn)
{
+ int ret;
+
if (insn->immediate.got)
- return;
- if (!insn->displacement.got)
- insn_get_displacement(insn);
+ return 0;
+
+ if (!insn->displacement.got) {
+ ret = insn_get_displacement(insn);
+ if (ret)
+ return ret;
+ }

if (inat_has_moffset(insn->attr)) {
if (!__get_moffset(insn))
@@ -604,9 +684,10 @@ void insn_get_immediate(struct insn *insn)
}
done:
insn->immediate.got = 1;
+ return 0;

err_out:
- return;
+ return -ENODATA;
}

/**
@@ -615,13 +696,58 @@ void insn_get_immediate(struct insn *insn)
*
* If necessary, first collects the instruction up to and including the
* immediates bytes.
- */
-void insn_get_length(struct insn *insn)
+ *
+ * Returns:
+ * - 0 on success
+ * - < 0 on error
+*/
+int insn_get_length(struct insn *insn)
{
+ int ret;
+
if (insn->length)
- return;
- if (!insn->immediate.got)
- insn_get_immediate(insn);
+ return 0;
+
+ if (!insn->immediate.got) {
+ ret = insn_get_immediate(insn);
+ if (ret)
+ return ret;
+ }
+
insn->length = (unsigned char)((unsigned long)insn->next_byte
- (unsigned long)insn->kaddr);
+
+ return 0;
+}
+
+/**
+ * insn_decode() - Decode an x86 instruction
+ * @insn: &struct insn to be initialized
+ * @kaddr: address (in kernel memory) of instruction (or copy thereof)
+ * @buf_len: length of the insn buffer at @kaddr
+ * @m: insn mode, see enum insn_mode
+ *
+ * Returns:
+ * 0: if decoding succeeded
+ * < 0: otherwise.
+ */
+int insn_decode(struct insn *insn, const void *kaddr, int buf_len, enum insn_mode m)
+{
+ int ret;
+
+/* #define INSN_MODE_KERN -1 __ignore_sync_check__ mode is only valid in the kernel */
+
+ if (m == INSN_MODE_KERN)
+ insn_init(insn, kaddr, buf_len, IS_ENABLED(CONFIG_X86_64));
+ else
+ insn_init(insn, kaddr, buf_len, m == INSN_MODE_64);
+
+ ret = insn_get_length(insn);
+ if (ret)
+ return ret;
+
+ if (insn_complete(insn))
+ return 0;
+
+ return -EINVAL;
}
diff --git a/arch/x86/lib/iomap_copy_64.S b/arch/x86/lib/iomap_copy_64.S
index cb5a1964506b..a1f9416bf67a 100644
--- a/arch/x86/lib/iomap_copy_64.S
+++ b/arch/x86/lib/iomap_copy_64.S
@@ -11,5 +11,5 @@
SYM_FUNC_START(__iowrite32_copy)
movl %edx,%ecx
rep movsd
- ret
+ RET
SYM_FUNC_END(__iowrite32_copy)
diff --git a/arch/x86/lib/memcpy_64.S b/arch/x86/lib/memcpy_64.S
index 1e299ac73c86..59cf2343f3d9 100644
--- a/arch/x86/lib/memcpy_64.S
+++ b/arch/x86/lib/memcpy_64.S
@@ -4,7 +4,7 @@
#include <linux/linkage.h>
#include <asm/errno.h>
#include <asm/cpufeatures.h>
-#include <asm/alternative-asm.h>
+#include <asm/alternative.h>
#include <asm/export.h>

.pushsection .noinstr.text, "ax"
@@ -39,7 +39,7 @@ SYM_FUNC_START_WEAK(memcpy)
rep movsq
movl %edx, %ecx
rep movsb
- ret
+ RET
SYM_FUNC_END(memcpy)
SYM_FUNC_END_ALIAS(__memcpy)
EXPORT_SYMBOL(memcpy)
@@ -53,7 +53,7 @@ SYM_FUNC_START_LOCAL(memcpy_erms)
movq %rdi, %rax
movq %rdx, %rcx
rep movsb
- ret
+ RET
SYM_FUNC_END(memcpy_erms)

SYM_FUNC_START_LOCAL(memcpy_orig)
@@ -137,7 +137,7 @@ SYM_FUNC_START_LOCAL(memcpy_orig)
movq %r9, 1*8(%rdi)
movq %r10, -2*8(%rdi, %rdx)
movq %r11, -1*8(%rdi, %rdx)
- retq
+ RET
.p2align 4
.Lless_16bytes:
cmpl $8, %edx
@@ -149,7 +149,7 @@ SYM_FUNC_START_LOCAL(memcpy_orig)
movq -1*8(%rsi, %rdx), %r9
movq %r8, 0*8(%rdi)
movq %r9, -1*8(%rdi, %rdx)
- retq
+ RET
.p2align 4
.Lless_8bytes:
cmpl $4, %edx
@@ -162,7 +162,7 @@ SYM_FUNC_START_LOCAL(memcpy_orig)
movl -4(%rsi, %rdx), %r8d
movl %ecx, (%rdi)
movl %r8d, -4(%rdi, %rdx)
- retq
+ RET
.p2align 4
.Lless_3bytes:
subl $1, %edx
@@ -180,7 +180,7 @@ SYM_FUNC_START_LOCAL(memcpy_orig)
movb %cl, (%rdi)

.Lend:
- retq
+ RET
SYM_FUNC_END(memcpy_orig)

.popsection
diff --git a/arch/x86/lib/memmove_64.S b/arch/x86/lib/memmove_64.S
index 41902fe8b859..4b8ee3a2fcc3 100644
--- a/arch/x86/lib/memmove_64.S
+++ b/arch/x86/lib/memmove_64.S
@@ -8,7 +8,7 @@
*/
#include <linux/linkage.h>
#include <asm/cpufeatures.h>
-#include <asm/alternative-asm.h>
+#include <asm/alternative.h>
#include <asm/export.h>

#undef memmove
@@ -40,7 +40,7 @@ SYM_FUNC_START(__memmove)
/* FSRM implies ERMS => no length checks, do the copy directly */
.Lmemmove_begin_forward:
ALTERNATIVE "cmp $0x20, %rdx; jb 1f", "", X86_FEATURE_FSRM
- ALTERNATIVE "", "movq %rdx, %rcx; rep movsb; retq", X86_FEATURE_ERMS
+ ALTERNATIVE "", "jmp .Lmemmove_erms", X86_FEATURE_ERMS

/*
* movsq instruction have many startup latency
@@ -205,7 +205,12 @@ SYM_FUNC_START(__memmove)
movb (%rsi), %r11b
movb %r11b, (%rdi)
13:
- retq
+ RET
+
+.Lmemmove_erms:
+ movq %rdx, %rcx
+ rep movsb
+ RET
SYM_FUNC_END(__memmove)
SYM_FUNC_END_ALIAS(memmove)
EXPORT_SYMBOL(__memmove)
diff --git a/arch/x86/lib/memset_64.S b/arch/x86/lib/memset_64.S
index 0bfd26e4ca9e..d624f2bc42f1 100644
--- a/arch/x86/lib/memset_64.S
+++ b/arch/x86/lib/memset_64.S
@@ -3,7 +3,7 @@

#include <linux/linkage.h>
#include <asm/cpufeatures.h>
-#include <asm/alternative-asm.h>
+#include <asm/alternative.h>
#include <asm/export.h>

/*
@@ -40,7 +40,7 @@ SYM_FUNC_START(__memset)
movl %edx,%ecx
rep stosb
movq %r9,%rax
- ret
+ RET
SYM_FUNC_END(__memset)
SYM_FUNC_END_ALIAS(memset)
EXPORT_SYMBOL(memset)
@@ -63,7 +63,7 @@ SYM_FUNC_START_LOCAL(memset_erms)
movq %rdx,%rcx
rep stosb
movq %r9,%rax
- ret
+ RET
SYM_FUNC_END(memset_erms)

SYM_FUNC_START_LOCAL(memset_orig)
@@ -125,7 +125,7 @@ SYM_FUNC_START_LOCAL(memset_orig)

.Lende:
movq %r10,%rax
- ret
+ RET

.Lbad_alignment:
cmpq $7,%rdx
diff --git a/arch/x86/lib/msr-reg.S b/arch/x86/lib/msr-reg.S
index a2b9caa5274c..ebd259f31496 100644
--- a/arch/x86/lib/msr-reg.S
+++ b/arch/x86/lib/msr-reg.S
@@ -35,7 +35,7 @@ SYM_FUNC_START(\op\()_safe_regs)
movl %edi, 28(%r10)
popq %r12
popq %rbx
- ret
+ RET
3:
movl $-EIO, %r11d
jmp 2b
@@ -77,7 +77,7 @@ SYM_FUNC_START(\op\()_safe_regs)
popl %esi
popl %ebp
popl %ebx
- ret
+ RET
3:
movl $-EIO, 4(%esp)
jmp 2b
diff --git a/arch/x86/lib/putuser.S b/arch/x86/lib/putuser.S
index 0ea344c5ea43..ecb2049c1273 100644
--- a/arch/x86/lib/putuser.S
+++ b/arch/x86/lib/putuser.S
@@ -52,7 +52,7 @@ SYM_INNER_LABEL(__put_user_nocheck_1, SYM_L_GLOBAL)
1: movb %al,(%_ASM_CX)
xor %ecx,%ecx
ASM_CLAC
- ret
+ RET
SYM_FUNC_END(__put_user_1)
EXPORT_SYMBOL(__put_user_1)
EXPORT_SYMBOL(__put_user_nocheck_1)
@@ -66,7 +66,7 @@ SYM_INNER_LABEL(__put_user_nocheck_2, SYM_L_GLOBAL)
2: movw %ax,(%_ASM_CX)
xor %ecx,%ecx
ASM_CLAC
- ret
+ RET
SYM_FUNC_END(__put_user_2)
EXPORT_SYMBOL(__put_user_2)
EXPORT_SYMBOL(__put_user_nocheck_2)
@@ -80,7 +80,7 @@ SYM_INNER_LABEL(__put_user_nocheck_4, SYM_L_GLOBAL)
3: movl %eax,(%_ASM_CX)
xor %ecx,%ecx
ASM_CLAC
- ret
+ RET
SYM_FUNC_END(__put_user_4)
EXPORT_SYMBOL(__put_user_4)
EXPORT_SYMBOL(__put_user_nocheck_4)
diff --git a/arch/x86/lib/retpoline.S b/arch/x86/lib/retpoline.S
index b4c43a9b1483..1221bb099afb 100644
--- a/arch/x86/lib/retpoline.S
+++ b/arch/x86/lib/retpoline.S
@@ -4,33 +4,37 @@
#include <linux/linkage.h>
#include <asm/dwarf2.h>
#include <asm/cpufeatures.h>
-#include <asm/alternative-asm.h>
+#include <asm/alternative.h>
#include <asm/export.h>
#include <asm/nospec-branch.h>
#include <asm/unwind_hints.h>
#include <asm/frame.h>

-.macro THUNK reg
.section .text.__x86.indirect_thunk

- .align 32
-SYM_FUNC_START(__x86_indirect_thunk_\reg)
- JMP_NOSPEC \reg
-SYM_FUNC_END(__x86_indirect_thunk_\reg)
-
-SYM_FUNC_START_NOALIGN(__x86_retpoline_\reg)
+.macro RETPOLINE reg
ANNOTATE_INTRA_FUNCTION_CALL
- call .Ldo_rop_\@
+ call .Ldo_rop_\@
.Lspec_trap_\@:
UNWIND_HINT_EMPTY
pause
lfence
- jmp .Lspec_trap_\@
+ jmp .Lspec_trap_\@
.Ldo_rop_\@:
- mov %\reg, (%_ASM_SP)
- UNWIND_HINT_RET_OFFSET
- ret
-SYM_FUNC_END(__x86_retpoline_\reg)
+ mov %\reg, (%_ASM_SP)
+ UNWIND_HINT_FUNC
+ RET
+.endm
+
+.macro THUNK reg
+
+ .align RETPOLINE_THUNK_SIZE
+SYM_INNER_LABEL(__x86_indirect_thunk_\reg, SYM_L_GLOBAL)
+ UNWIND_HINT_EMPTY
+
+ ALTERNATIVE_2 __stringify(RETPOLINE \reg), \
+ __stringify(lfence; ANNOTATE_RETPOLINE_SAFE; jmp *%\reg; int3), X86_FEATURE_RETPOLINE_LFENCE, \
+ __stringify(ANNOTATE_RETPOLINE_SAFE; jmp *%\reg), ALT_NOT(X86_FEATURE_RETPOLINE)

.endm

@@ -48,16 +52,90 @@ SYM_FUNC_END(__x86_retpoline_\reg)

#define __EXPORT_THUNK(sym) _ASM_NOKPROBE(sym); EXPORT_SYMBOL(sym)
#define EXPORT_THUNK(reg) __EXPORT_THUNK(__x86_indirect_thunk_ ## reg)
-#define EXPORT_RETPOLINE(reg) __EXPORT_THUNK(__x86_retpoline_ ## reg)

-#undef GEN
+ .align RETPOLINE_THUNK_SIZE
+SYM_CODE_START(__x86_indirect_thunk_array)
+
#define GEN(reg) THUNK reg
#include <asm/GEN-for-each-reg.h>
-
#undef GEN
+
+ .align RETPOLINE_THUNK_SIZE
+SYM_CODE_END(__x86_indirect_thunk_array)
+
#define GEN(reg) EXPORT_THUNK(reg)
#include <asm/GEN-for-each-reg.h>
-
#undef GEN
-#define GEN(reg) EXPORT_RETPOLINE(reg)
-#include <asm/GEN-for-each-reg.h>
+
+/*
+ * This function name is magical and is used by -mfunction-return=thunk-extern
+ * for the compiler to generate JMPs to it.
+ */
+#ifdef CONFIG_RETHUNK
+
+ .section .text.__x86.return_thunk
+
+/*
+ * Safety details here pertain to the AMD Zen{1,2} microarchitecture:
+ * 1) The RET at __x86_return_thunk must be on a 64 byte boundary, for
+ * alignment within the BTB.
+ * 2) The instruction at zen_untrain_ret must contain, and not
+ * end with, the 0xc3 byte of the RET.
+ * 3) STIBP must be enabled, or SMT disabled, to prevent the sibling thread
+ * from re-poisioning the BTB prediction.
+ */
+ .align 64
+ .skip 63, 0xcc
+SYM_FUNC_START_NOALIGN(zen_untrain_ret);
+
+ /*
+ * As executed from zen_untrain_ret, this is:
+ *
+ * TEST $0xcc, %bl
+ * LFENCE
+ * JMP __x86_return_thunk
+ *
+ * Executing the TEST instruction has a side effect of evicting any BTB
+ * prediction (potentially attacker controlled) attached to the RET, as
+ * __x86_return_thunk + 1 isn't an instruction boundary at the moment.
+ */
+ .byte 0xf6
+
+ /*
+ * As executed from __x86_return_thunk, this is a plain RET.
+ *
+ * As part of the TEST above, RET is the ModRM byte, and INT3 the imm8.
+ *
+ * We subsequently jump backwards and architecturally execute the RET.
+ * This creates a correct BTB prediction (type=ret), but in the
+ * meantime we suffer Straight Line Speculation (because the type was
+ * no branch) which is halted by the INT3.
+ *
+ * With SMT enabled and STIBP active, a sibling thread cannot poison
+ * RET's prediction to a type of its choice, but can evict the
+ * prediction due to competitive sharing. If the prediction is
+ * evicted, __x86_return_thunk will suffer Straight Line Speculation
+ * which will be contained safely by the INT3.
+ */
+SYM_INNER_LABEL(__x86_return_thunk, SYM_L_GLOBAL)
+ ret
+ int3
+SYM_CODE_END(__x86_return_thunk)
+
+ /*
+ * Ensure the TEST decoding / BTB invalidation is complete.
+ */
+ lfence
+
+ /*
+ * Jump back and execute the RET in the middle of the TEST instruction.
+ * INT3 is for SLS protection.
+ */
+ jmp __x86_return_thunk
+ int3
+SYM_FUNC_END(zen_untrain_ret)
+__EXPORT_THUNK(zen_untrain_ret)
+
+EXPORT_SYMBOL(__x86_return_thunk)
+
+#endif /* CONFIG_RETHUNK */
diff --git a/arch/x86/math-emu/div_Xsig.S b/arch/x86/math-emu/div_Xsig.S
index 951da2ad54bb..8c270ab415be 100644
--- a/arch/x86/math-emu/div_Xsig.S
+++ b/arch/x86/math-emu/div_Xsig.S
@@ -341,7 +341,7 @@ L_exit:
popl %esi

leave
- ret
+ RET

#ifdef PARANOID
diff --git a/arch/x86/math-emu/div_small.S b/arch/x86/math-emu/div_small.S
index d047d1816abe..637439bfefa4 100644
--- a/arch/x86/math-emu/div_small.S
+++ b/arch/x86/math-emu/div_small.S
@@ -44,5 +44,5 @@ SYM_FUNC_START(FPU_div_small)
popl %esi

leave
- ret
+ RET
SYM_FUNC_END(FPU_div_small)
diff --git a/arch/x86/math-emu/mul_Xsig.S b/arch/x86/math-emu/mul_Xsig.S
index 4afc7b1fa6e9..54a031b66142 100644
--- a/arch/x86/math-emu/mul_Xsig.S
+++ b/arch/x86/math-emu/mul_Xsig.S
@@ -62,7 +62,7 @@ SYM_FUNC_START(mul32_Xsig)

popl %esi
leave
- ret
+ RET
SYM_FUNC_END(mul32_Xsig)

@@ -115,7 +115,7 @@ SYM_FUNC_START(mul64_Xsig)

popl %esi
leave
- ret
+ RET
SYM_FUNC_END(mul64_Xsig)

@@ -175,5 +175,5 @@ SYM_FUNC_START(mul_Xsig_Xsig)

popl %esi
leave
- ret
+ RET
SYM_FUNC_END(mul_Xsig_Xsig)
diff --git a/arch/x86/math-emu/polynom_Xsig.S b/arch/x86/math-emu/polynom_Xsig.S
index 702315eecb86..35fd723fc0df 100644
--- a/arch/x86/math-emu/polynom_Xsig.S
+++ b/arch/x86/math-emu/polynom_Xsig.S
@@ -133,5 +133,5 @@ L_accum_done:
popl %edi
popl %esi
leave
- ret
+ RET
SYM_FUNC_END(polynomial_Xsig)
diff --git a/arch/x86/math-emu/reg_norm.S b/arch/x86/math-emu/reg_norm.S
index cad1d60b1e84..594936eeed67 100644
--- a/arch/x86/math-emu/reg_norm.S
+++ b/arch/x86/math-emu/reg_norm.S
@@ -72,7 +72,7 @@ L_exit_valid:
L_exit:
popl %ebx
leave
- ret
+ RET

L_zero:
@@ -138,7 +138,7 @@ L_exit_nuo_valid:

popl %ebx
leave
- ret
+ RET

L_exit_nuo_zero:
movl TAG_Zero,%eax
@@ -146,5 +146,5 @@ L_exit_nuo_zero:

popl %ebx
leave
- ret
+ RET
SYM_FUNC_END(FPU_normalize_nuo)
diff --git a/arch/x86/math-emu/reg_round.S b/arch/x86/math-emu/reg_round.S
index 11a1f798451b..8bdbdcee7456 100644
--- a/arch/x86/math-emu/reg_round.S
+++ b/arch/x86/math-emu/reg_round.S
@@ -437,7 +437,7 @@ fpu_Arith_exit:
popl %edi
popl %esi
leave
- ret
+ RET

/*
diff --git a/arch/x86/math-emu/reg_u_add.S b/arch/x86/math-emu/reg_u_add.S
index 9c9e2c810afe..07247287a3af 100644
--- a/arch/x86/math-emu/reg_u_add.S
+++ b/arch/x86/math-emu/reg_u_add.S
@@ -164,6 +164,6 @@ L_exit:
popl %edi
popl %esi
leave
- ret
+ RET
#endif /* PARANOID */
SYM_FUNC_END(FPU_u_add)
diff --git a/arch/x86/math-emu/reg_u_div.S b/arch/x86/math-emu/reg_u_div.S
index e2fb5c2644c5..b5a41e2fc484 100644
--- a/arch/x86/math-emu/reg_u_div.S
+++ b/arch/x86/math-emu/reg_u_div.S
@@ -468,7 +468,7 @@ L_exit:
popl %esi

leave
- ret
+ RET
#endif /* PARANOID */

SYM_FUNC_END(FPU_u_div)
diff --git a/arch/x86/math-emu/reg_u_mul.S b/arch/x86/math-emu/reg_u_mul.S
index 0c779c87ac5b..e2588b24b8c2 100644
--- a/arch/x86/math-emu/reg_u_mul.S
+++ b/arch/x86/math-emu/reg_u_mul.S
@@ -144,7 +144,7 @@ L_exit:
popl %edi
popl %esi
leave
- ret
+ RET
#endif /* PARANOID */

SYM_FUNC_END(FPU_u_mul)
diff --git a/arch/x86/math-emu/reg_u_sub.S b/arch/x86/math-emu/reg_u_sub.S
index e9bb7c248649..4c900c29e4ff 100644
--- a/arch/x86/math-emu/reg_u_sub.S
+++ b/arch/x86/math-emu/reg_u_sub.S
@@ -270,5 +270,5 @@ L_exit:
popl %edi
popl %esi
leave
- ret
+ RET
SYM_FUNC_END(FPU_u_sub)
diff --git a/arch/x86/math-emu/round_Xsig.S b/arch/x86/math-emu/round_Xsig.S
index d9d7de8dbd7b..126c40473bad 100644
--- a/arch/x86/math-emu/round_Xsig.S
+++ b/arch/x86/math-emu/round_Xsig.S
@@ -78,7 +78,7 @@ L_exit:
popl %esi
popl %ebx
leave
- ret
+ RET
SYM_FUNC_END(round_Xsig)

@@ -138,5 +138,5 @@ L_n_exit:
popl %esi
popl %ebx
leave
- ret
+ RET
SYM_FUNC_END(norm_Xsig)
diff --git a/arch/x86/math-emu/shr_Xsig.S b/arch/x86/math-emu/shr_Xsig.S
index 726af985f758..f726bf6f6396 100644
--- a/arch/x86/math-emu/shr_Xsig.S
+++ b/arch/x86/math-emu/shr_Xsig.S
@@ -45,7 +45,7 @@ SYM_FUNC_START(shr_Xsig)
popl %ebx
popl %esi
leave
- ret
+ RET

L_more_than_31:
cmpl $64,%ecx
@@ -61,7 +61,7 @@ L_more_than_31:
movl $0,8(%esi)
popl %esi
leave
- ret
+ RET

L_more_than_63:
cmpl $96,%ecx
@@ -76,7 +76,7 @@ L_more_than_63:
movl %edx,8(%esi)
popl %esi
leave
- ret
+ RET

L_more_than_95:
xorl %eax,%eax
@@ -85,5 +85,5 @@ L_more_than_95:
movl %eax,8(%esi)
popl %esi
leave
- ret
+ RET
SYM_FUNC_END(shr_Xsig)
diff --git a/arch/x86/math-emu/wm_shrx.S b/arch/x86/math-emu/wm_shrx.S
index 4fc89174caf0..f608a28a4c43 100644
--- a/arch/x86/math-emu/wm_shrx.S
+++ b/arch/x86/math-emu/wm_shrx.S
@@ -55,7 +55,7 @@ SYM_FUNC_START(FPU_shrx)
popl %ebx
popl %esi
leave
- ret
+ RET

L_more_than_31:
cmpl $64,%ecx
@@ -70,7 +70,7 @@ L_more_than_31:
movl $0,4(%esi)
popl %esi
leave
- ret
+ RET

L_more_than_63:
cmpl $96,%ecx
@@ -84,7 +84,7 @@ L_more_than_63:
movl %edx,4(%esi)
popl %esi
leave
- ret
+ RET

L_more_than_95:
xorl %eax,%eax
@@ -92,7 +92,7 @@ L_more_than_95:
movl %eax,4(%esi)
popl %esi
leave
- ret
+ RET
SYM_FUNC_END(FPU_shrx)

@@ -146,7 +146,7 @@ SYM_FUNC_START(FPU_shrxs)
popl %ebx
popl %esi
leave
- ret
+ RET

/* Shift by [0..31] bits */
Ls_less_than_32:
@@ -163,7 +163,7 @@ Ls_less_than_32:
popl %ebx
popl %esi
leave
- ret
+ RET

/* Shift by [64..95] bits */
Ls_more_than_63:
@@ -189,7 +189,7 @@ Ls_more_than_63:
popl %ebx
popl %esi
leave
- ret
+ RET

Ls_more_than_95:
/* Shift by [96..inf) bits */
@@ -203,5 +203,5 @@ Ls_more_than_95:
popl %ebx
popl %esi
leave
- ret
+ RET
SYM_FUNC_END(FPU_shrxs)
diff --git a/arch/x86/mm/mem_encrypt_boot.S b/arch/x86/mm/mem_encrypt_boot.S
index 7a84fc8bc5c3..145b67299ab6 100644
--- a/arch/x86/mm/mem_encrypt_boot.S
+++ b/arch/x86/mm/mem_encrypt_boot.S
@@ -65,7 +65,10 @@ SYM_FUNC_START(sme_encrypt_execute)
movq %rbp, %rsp /* Restore original stack pointer */
pop %rbp

+ /* Offset to __x86_return_thunk would be wrong here */
+ ANNOTATE_UNRET_SAFE
ret
+ int3
SYM_FUNC_END(sme_encrypt_execute)

SYM_FUNC_START(__enc_copy)
@@ -151,6 +154,9 @@ SYM_FUNC_START(__enc_copy)
pop %r12
pop %r15

+ /* Offset to __x86_return_thunk would be wrong here */
+ ANNOTATE_UNRET_SAFE
ret
+ int3
.L__enc_copy_end:
SYM_FUNC_END(__enc_copy)
diff --git a/arch/x86/net/bpf_jit_comp.c b/arch/x86/net/bpf_jit_comp.c
index 1714e85eb26d..8e3c3d8916dd 100644
--- a/arch/x86/net/bpf_jit_comp.c
+++ b/arch/x86/net/bpf_jit_comp.c
@@ -15,7 +15,6 @@
#include <asm/set_memory.h>
#include <asm/nospec-branch.h>
#include <asm/text-patching.h>
-#include <asm/asm-prototypes.h>

static u8 *emit_code(u8 *ptr, u32 bytes, unsigned int len)
{
@@ -213,6 +212,14 @@ static void jit_fill_hole(void *area, unsigned int size)

struct jit_context {
int cleanup_addr; /* Epilogue code offset */
+
+ /*
+ * Program specific offsets of labels in the code; these rely on the
+ * JIT doing at least 2 passes, recording the position on the first
+ * pass, only to generate the correct offset on the second pass.
+ */
+ int tail_call_direct_label;
+ int tail_call_indirect_label;
};

/* Maximum number of bytes emitted while JITing one eBPF insn */
@@ -372,20 +379,40 @@ int bpf_arch_text_poke(void *ip, enum bpf_text_poke_type t,
return __bpf_arch_text_poke(ip, t, old_addr, new_addr, true);
}

-static int get_pop_bytes(bool *callee_regs_used)
+#define EMIT_LFENCE() EMIT3(0x0F, 0xAE, 0xE8)
+
+static void emit_indirect_jump(u8 **pprog, int reg, u8 *ip)
{
- int bytes = 0;
+ u8 *prog = *pprog;
+ int cnt = 0;

- if (callee_regs_used[3])
- bytes += 2;
- if (callee_regs_used[2])
- bytes += 2;
- if (callee_regs_used[1])
- bytes += 2;
- if (callee_regs_used[0])
- bytes += 1;
+#ifdef CONFIG_RETPOLINE
+ if (cpu_feature_enabled(X86_FEATURE_RETPOLINE_LFENCE)) {
+ EMIT_LFENCE();
+ EMIT2(0xFF, 0xE0 + reg);
+ } else if (cpu_feature_enabled(X86_FEATURE_RETPOLINE)) {
+ emit_jump(&prog, &__x86_indirect_thunk_array[reg], ip);
+ } else
+#endif
+ EMIT2(0xFF, 0xE0 + reg);
+
+ *pprog = prog;
+}
+
+static void emit_return(u8 **pprog, u8 *ip)
+{
+ u8 *prog = *pprog;
+ int cnt = 0;
+
+ if (cpu_feature_enabled(X86_FEATURE_RETHUNK)) {
+ emit_jump(&prog, &__x86_return_thunk, ip);
+ } else {
+ EMIT1(0xC3); /* ret */
+ if (IS_ENABLED(CONFIG_SLS))
+ EMIT1(0xCC); /* int3 */
+ }

- return bytes;
+ *pprog = prog;
}

/*
@@ -403,30 +430,12 @@ static int get_pop_bytes(bool *callee_regs_used)
* out:
*/
static void emit_bpf_tail_call_indirect(u8 **pprog, bool *callee_regs_used,
- u32 stack_depth)
+ u32 stack_depth, u8 *ip,
+ struct jit_context *ctx)
{
int tcc_off = -4 - round_up(stack_depth, 8);
- u8 *prog = *pprog;
- int pop_bytes = 0;
- int off1 = 42;
- int off2 = 31;
- int off3 = 9;
- int cnt = 0;
-
- /* count the additional bytes used for popping callee regs from stack
- * that need to be taken into account for each of the offsets that
- * are used for bailing out of the tail call
- */
- pop_bytes = get_pop_bytes(callee_regs_used);
- off1 += pop_bytes;
- off2 += pop_bytes;
- off3 += pop_bytes;
-
- if (stack_depth) {
- off1 += 7;
- off2 += 7;
- off3 += 7;
- }
+ u8 *prog = *pprog, *start = *pprog;
+ int cnt = 0, offset;

/*
* rdi - pointer to ctx
@@ -441,8 +450,9 @@ static void emit_bpf_tail_call_indirect(u8 **pprog, bool *callee_regs_used,
EMIT2(0x89, 0xD2); /* mov edx, edx */
EMIT3(0x39, 0x56, /* cmp dword ptr [rsi + 16], edx */
offsetof(struct bpf_array, map.max_entries));
-#define OFFSET1 (off1 + RETPOLINE_RCX_BPF_JIT_SIZE) /* Number of bytes to jump */
- EMIT2(X86_JBE, OFFSET1); /* jbe out */
+
+ offset = ctx->tail_call_indirect_label - (prog + 2 - start);
+ EMIT2(X86_JBE, offset); /* jbe out */

/*
* if (tail_call_cnt > MAX_TAIL_CALL_CNT)
@@ -450,8 +460,9 @@ static void emit_bpf_tail_call_indirect(u8 **pprog, bool *callee_regs_used,
*/
EMIT2_off32(0x8B, 0x85, tcc_off); /* mov eax, dword ptr [rbp - tcc_off] */
EMIT3(0x83, 0xF8, MAX_TAIL_CALL_CNT); /* cmp eax, MAX_TAIL_CALL_CNT */
-#define OFFSET2 (off2 + RETPOLINE_RCX_BPF_JIT_SIZE)
- EMIT2(X86_JA, OFFSET2); /* ja out */
+
+ offset = ctx->tail_call_indirect_label - (prog + 2 - start);
+ EMIT2(X86_JA, offset); /* ja out */
EMIT3(0x83, 0xC0, 0x01); /* add eax, 1 */
EMIT2_off32(0x89, 0x85, tcc_off); /* mov dword ptr [rbp - tcc_off], eax */

@@ -464,12 +475,11 @@ static void emit_bpf_tail_call_indirect(u8 **pprog, bool *callee_regs_used,
* goto out;
*/
EMIT3(0x48, 0x85, 0xC9); /* test rcx,rcx */
-#define OFFSET3 (off3 + RETPOLINE_RCX_BPF_JIT_SIZE)
- EMIT2(X86_JE, OFFSET3); /* je out */

- *pprog = prog;
- pop_callee_regs(pprog, callee_regs_used);
- prog = *pprog;
+ offset = ctx->tail_call_indirect_label - (prog + 2 - start);
+ EMIT2(X86_JE, offset); /* je out */
+
+ pop_callee_regs(&prog, callee_regs_used);

EMIT1(0x58); /* pop rax */
if (stack_depth)
@@ -486,42 +496,21 @@ static void emit_bpf_tail_call_indirect(u8 **pprog, bool *callee_regs_used,
* rdi == ctx (1st arg)
* rcx == prog->bpf_func + X86_TAIL_CALL_OFFSET
*/
- RETPOLINE_RCX_BPF_JIT();
+ emit_indirect_jump(&prog, 1 /* rcx */, ip + (prog - start));

/* out: */
+ ctx->tail_call_indirect_label = prog - start;
*pprog = prog;
}

static void emit_bpf_tail_call_direct(struct bpf_jit_poke_descriptor *poke,
- u8 **pprog, int addr, u8 *image,
- bool *callee_regs_used, u32 stack_depth)
+ u8 **pprog, u8 *ip,
+ bool *callee_regs_used, u32 stack_depth,
+ struct jit_context *ctx)
{
int tcc_off = -4 - round_up(stack_depth, 8);
- u8 *prog = *pprog;
- int pop_bytes = 0;
- int off1 = 20;
- int poke_off;
- int cnt = 0;
-
- /* count the additional bytes used for popping callee regs to stack
- * that need to be taken into account for jump offset that is used for
- * bailing out from of the tail call when limit is reached
- */
- pop_bytes = get_pop_bytes(callee_regs_used);
- off1 += pop_bytes;
-
- /*
- * total bytes for:
- * - nop5/ jmpq $off
- * - pop callee regs
- * - sub rsp, $val if depth > 0
- * - pop rax
- */
- poke_off = X86_PATCH_SIZE + pop_bytes + 1;
- if (stack_depth) {
- poke_off += 7;
- off1 += 7;
- }
+ u8 *prog = *pprog, *start = *pprog;
+ int cnt = 0, offset;

/*
* if (tail_call_cnt > MAX_TAIL_CALL_CNT)
@@ -529,28 +518,30 @@ static void emit_bpf_tail_call_direct(struct bpf_jit_poke_descriptor *poke,
*/
EMIT2_off32(0x8B, 0x85, tcc_off); /* mov eax, dword ptr [rbp - tcc_off] */
EMIT3(0x83, 0xF8, MAX_TAIL_CALL_CNT); /* cmp eax, MAX_TAIL_CALL_CNT */
- EMIT2(X86_JA, off1); /* ja out */
+
+ offset = ctx->tail_call_direct_label - (prog + 2 - start);
+ EMIT2(X86_JA, offset); /* ja out */
EMIT3(0x83, 0xC0, 0x01); /* add eax, 1 */
EMIT2_off32(0x89, 0x85, tcc_off); /* mov dword ptr [rbp - tcc_off], eax */

- poke->tailcall_bypass = image + (addr - poke_off - X86_PATCH_SIZE);
+ poke->tailcall_bypass = ip + (prog - start);
poke->adj_off = X86_TAIL_CALL_OFFSET;
- poke->tailcall_target = image + (addr - X86_PATCH_SIZE);
+ poke->tailcall_target = ip + ctx->tail_call_direct_label - X86_PATCH_SIZE;
poke->bypass_addr = (u8 *)poke->tailcall_target + X86_PATCH_SIZE;

emit_jump(&prog, (u8 *)poke->tailcall_target + X86_PATCH_SIZE,
poke->tailcall_bypass);

- *pprog = prog;
- pop_callee_regs(pprog, callee_regs_used);
- prog = *pprog;
+ pop_callee_regs(&prog, callee_regs_used);
EMIT1(0x58); /* pop rax */
if (stack_depth)
EMIT3_off32(0x48, 0x81, 0xC4, round_up(stack_depth, 8));

memcpy(prog, ideal_nops[NOP_ATOMIC5], X86_PATCH_SIZE);
prog += X86_PATCH_SIZE;
+
/* out: */
+ ctx->tail_call_direct_label = prog - start;

*pprog = prog;
}
@@ -1144,8 +1135,7 @@ static int do_jit(struct bpf_prog *bpf_prog, int *addrs, u8 *image,
/* speculation barrier */
case BPF_ST | BPF_NOSPEC:
if (boot_cpu_has(X86_FEATURE_XMM2))
- /* Emit 'lfence' */
- EMIT3(0x0F, 0xAE, 0xE8);
+ EMIT_LFENCE();
break;

/* ST: *(u8*)(dst_reg + off) = imm */
@@ -1275,13 +1265,16 @@ xadd: if (is_imm8(insn->off))
case BPF_JMP | BPF_TAIL_CALL:
if (imm32)
emit_bpf_tail_call_direct(&bpf_prog->aux->poke_tab[imm32 - 1],
- &prog, addrs[i], image,
+ &prog, image + addrs[i - 1],
callee_regs_used,
- bpf_prog->aux->stack_depth);
+ bpf_prog->aux->stack_depth,
+ ctx);
else
emit_bpf_tail_call_indirect(&prog,
callee_regs_used,
- bpf_prog->aux->stack_depth);
+ bpf_prog->aux->stack_depth,
+ image + addrs[i - 1],
+ ctx);
break;

/* cond jump */
@@ -1466,7 +1459,7 @@ xadd: if (is_imm8(insn->off))
ctx->cleanup_addr = proglen;
pop_callee_regs(&prog, callee_regs_used);
EMIT1(0xC9); /* leave */
- EMIT1(0xC3); /* ret */
+ emit_return(&prog, image + addrs[i - 1] + (prog - temp));
break;

default:
@@ -1907,7 +1900,7 @@ int arch_prepare_bpf_trampoline(struct bpf_tramp_image *im, void *image, void *i
if (flags & BPF_TRAMP_F_SKIP_FRAME)
/* skip our return address and return to parent */
EMIT4(0x48, 0x83, 0xC4, 8); /* add rsp, 8 */
- EMIT1(0xC3); /* ret */
+ emit_return(&prog, prog);
/* Make sure the trampoline generation logic doesn't overflow */
if (WARN_ON_ONCE(prog > (u8 *)image_end - BPF_INSN_SAFETY)) {
ret = -EFAULT;
@@ -1920,26 +1913,6 @@ int arch_prepare_bpf_trampoline(struct bpf_tramp_image *im, void *image, void *i
return ret;
}

-static int emit_fallback_jump(u8 **pprog)
-{
- u8 *prog = *pprog;
- int err = 0;
-
-#ifdef CONFIG_RETPOLINE
- /* Note that this assumes the the compiler uses external
- * thunks for indirect calls. Both clang and GCC use the same
- * naming convention for external thunks.
- */
- err = emit_jump(&prog, __x86_indirect_thunk_rdx, prog);
-#else
- int cnt = 0;
-
- EMIT2(0xFF, 0xE2); /* jmp rdx */
-#endif
- *pprog = prog;
- return err;
-}
-
static int emit_bpf_dispatcher(u8 **pprog, int a, int b, s64 *progs)
{
u8 *jg_reloc, *prog = *pprog;
@@ -1961,9 +1934,7 @@ static int emit_bpf_dispatcher(u8 **pprog, int a, int b, s64 *progs)
if (err)
return err;

- err = emit_fallback_jump(&prog); /* jmp thunk/indirect */
- if (err)
- return err;
+ emit_indirect_jump(&prog, 2 /* rdx */, prog);

*pprog = prog;
return 0;
diff --git a/arch/x86/net/bpf_jit_comp32.c b/arch/x86/net/bpf_jit_comp32.c
index 4bd0f98df700..622af951220c 100644
--- a/arch/x86/net/bpf_jit_comp32.c
+++ b/arch/x86/net/bpf_jit_comp32.c
@@ -15,6 +15,7 @@
#include <asm/cacheflush.h>
#include <asm/set_memory.h>
#include <asm/nospec-branch.h>
+#include <asm/asm-prototypes.h>
#include <linux/bpf.h>

/*
@@ -1267,6 +1268,21 @@ static void emit_epilogue(u8 **pprog, u32 stack_depth)
*pprog = prog;
}

+static int emit_jmp_edx(u8 **pprog, u8 *ip)
+{
+ u8 *prog = *pprog;
+ int cnt = 0;
+
+#ifdef CONFIG_RETPOLINE
+ EMIT1_off32(0xE9, (u8 *)__x86_indirect_thunk_edx - (ip + 5));
+#else
+ EMIT2(0xFF, 0xE2);
+#endif
+ *pprog = prog;
+
+ return cnt;
+}
+
/*
* Generate the following code:
* ... bpf_tail_call(void *ctx, struct bpf_array *array, u64 index) ...
@@ -1280,7 +1296,7 @@ static void emit_epilogue(u8 **pprog, u32 stack_depth)
* goto *(prog->bpf_func + prologue_size);
* out:
*/
-static void emit_bpf_tail_call(u8 **pprog)
+static void emit_bpf_tail_call(u8 **pprog, u8 *ip)
{
u8 *prog = *pprog;
int cnt = 0;
@@ -1362,7 +1378,7 @@ static void emit_bpf_tail_call(u8 **pprog)
* eax == ctx (1st arg)
* edx == prog->bpf_func + prologue_size
*/
- RETPOLINE_EDX_BPF_JIT();
+ cnt += emit_jmp_edx(&prog, ip + cnt);

if (jmp_label1 == -1)
jmp_label1 = cnt;
@@ -1929,7 +1945,7 @@ static int do_jit(struct bpf_prog *bpf_prog, int *addrs, u8 *image,
break;
}
case BPF_JMP | BPF_TAIL_CALL:
- emit_bpf_tail_call(&prog);
+ emit_bpf_tail_call(&prog, image + addrs[i - 1]);
break;

/* cond jump */
diff --git a/arch/x86/platform/efi/efi_stub_32.S b/arch/x86/platform/efi/efi_stub_32.S
index 09ec84f6ef51..f3cfdb1c9a35 100644
--- a/arch/x86/platform/efi/efi_stub_32.S
+++ b/arch/x86/platform/efi/efi_stub_32.S
@@ -56,5 +56,5 @@ SYM_FUNC_START(efi_call_svam)

movl 16(%esp), %ebx
leave
- ret
+ RET
SYM_FUNC_END(efi_call_svam)
diff --git a/arch/x86/platform/efi/efi_stub_64.S b/arch/x86/platform/efi/efi_stub_64.S
index 90380a17ab23..2206b8bc47b8 100644
--- a/arch/x86/platform/efi/efi_stub_64.S
+++ b/arch/x86/platform/efi/efi_stub_64.S
@@ -23,5 +23,5 @@ SYM_FUNC_START(__efi_call)
mov %rsi, %rcx
CALL_NOSPEC rdi
leave
- ret
+ RET
SYM_FUNC_END(__efi_call)
diff --git a/arch/x86/platform/efi/efi_thunk_64.S b/arch/x86/platform/efi/efi_thunk_64.S
index 26f0da238c1c..9eac088ef4de 100644
--- a/arch/x86/platform/efi/efi_thunk_64.S
+++ b/arch/x86/platform/efi/efi_thunk_64.S
@@ -22,6 +22,7 @@
#include <linux/linkage.h>
#include <asm/page_types.h>
#include <asm/segment.h>
+#include <asm/nospec-branch.h>

.text
.code64
@@ -63,7 +64,9 @@ SYM_CODE_START(__efi64_thunk)
1: movq 24(%rsp), %rsp
pop %rbx
pop %rbp
- retq
+ ANNOTATE_UNRET_SAFE
+ ret
+ int3

.code32
2: pushl $__KERNEL_CS
diff --git a/arch/x86/platform/olpc/xo1-wakeup.S b/arch/x86/platform/olpc/xo1-wakeup.S
index 75f4faff8468..3a5abffe5660 100644
--- a/arch/x86/platform/olpc/xo1-wakeup.S
+++ b/arch/x86/platform/olpc/xo1-wakeup.S
@@ -77,7 +77,7 @@ save_registers:
pushfl
popl saved_context_eflags

- ret
+ RET

restore_registers:
movl saved_context_ebp, %ebp
@@ -88,7 +88,7 @@ restore_registers:
pushl saved_context_eflags
popfl

- ret
+ RET

SYM_CODE_START(do_olpc_suspend_lowlevel)
call save_processor_state
@@ -109,7 +109,7 @@ ret_point:

call restore_registers
call restore_processor_state
- ret
+ RET
SYM_CODE_END(do_olpc_suspend_lowlevel)

.data
diff --git a/arch/x86/power/hibernate_asm_32.S b/arch/x86/power/hibernate_asm_32.S
index 8786653ad3c0..5606a15cf9a1 100644
--- a/arch/x86/power/hibernate_asm_32.S
+++ b/arch/x86/power/hibernate_asm_32.S
@@ -32,7 +32,7 @@ SYM_FUNC_START(swsusp_arch_suspend)
FRAME_BEGIN
call swsusp_save
FRAME_END
- ret
+ RET
SYM_FUNC_END(swsusp_arch_suspend)

SYM_CODE_START(restore_image)
@@ -108,5 +108,5 @@ SYM_FUNC_START(restore_registers)
/* tell the hibernation core that we've just restored the memory */
movl %eax, in_suspend

- ret
+ RET
SYM_FUNC_END(restore_registers)
diff --git a/arch/x86/power/hibernate_asm_64.S b/arch/x86/power/hibernate_asm_64.S
index 7918b8415f13..3ae7a3d7d61e 100644
--- a/arch/x86/power/hibernate_asm_64.S
+++ b/arch/x86/power/hibernate_asm_64.S
@@ -49,7 +49,7 @@ SYM_FUNC_START(swsusp_arch_suspend)
FRAME_BEGIN
call swsusp_save
FRAME_END
- ret
+ RET
SYM_FUNC_END(swsusp_arch_suspend)

SYM_CODE_START(restore_image)
@@ -143,5 +143,5 @@ SYM_FUNC_START(restore_registers)
/* tell the hibernation core that we've just restored the memory */
movq %rax, in_suspend(%rip)

- ret
+ RET
SYM_FUNC_END(restore_registers)
diff --git a/arch/x86/um/checksum_32.S b/arch/x86/um/checksum_32.S
index 13f118dec74f..aed782ab7721 100644
--- a/arch/x86/um/checksum_32.S
+++ b/arch/x86/um/checksum_32.S
@@ -110,7 +110,7 @@ csum_partial:
7:
popl %ebx
popl %esi
- ret
+ RET

#else

@@ -208,7 +208,7 @@ csum_partial:
80:
popl %ebx
popl %esi
- ret
+ RET

#endif
EXPORT_SYMBOL(csum_partial)
diff --git a/arch/x86/um/setjmp_32.S b/arch/x86/um/setjmp_32.S
index 62eaf8c80e04..2d991ddbcca5 100644
--- a/arch/x86/um/setjmp_32.S
+++ b/arch/x86/um/setjmp_32.S
@@ -34,7 +34,7 @@ kernel_setjmp:
movl %esi,12(%edx)
movl %edi,16(%edx)
movl %ecx,20(%edx) # Return address
- ret
+ RET

.size kernel_setjmp,.-kernel_setjmp

diff --git a/arch/x86/um/setjmp_64.S b/arch/x86/um/setjmp_64.S
index 1b5d40d4ff46..b46acb6a8ebd 100644
--- a/arch/x86/um/setjmp_64.S
+++ b/arch/x86/um/setjmp_64.S
@@ -33,7 +33,7 @@ kernel_setjmp:
movq %r14,40(%rdi)
movq %r15,48(%rdi)
movq %rsi,56(%rdi) # Return address
- ret
+ RET

.size kernel_setjmp,.-kernel_setjmp

diff --git a/arch/x86/xen/Makefile b/arch/x86/xen/Makefile
index fc5c5ba4aacb..40b5779fce21 100644
--- a/arch/x86/xen/Makefile
+++ b/arch/x86/xen/Makefile
@@ -1,5 +1,4 @@
# SPDX-License-Identifier: GPL-2.0
-OBJECT_FILES_NON_STANDARD_xen-asm.o := y

ifdef CONFIG_FUNCTION_TRACER
# Do not profile debug and lowlevel utilities
diff --git a/arch/x86/xen/setup.c b/arch/x86/xen/setup.c
index 8bfc10330107..1f80dd3a2dd4 100644
--- a/arch/x86/xen/setup.c
+++ b/arch/x86/xen/setup.c
@@ -922,7 +922,7 @@ void xen_enable_sysenter(void)
if (!boot_cpu_has(sysenter_feature))
return;

- ret = register_callback(CALLBACKTYPE_sysenter, xen_sysenter_target);
+ ret = register_callback(CALLBACKTYPE_sysenter, xen_entry_SYSENTER_compat);
if(ret != 0)
setup_clear_cpu_cap(sysenter_feature);
}
@@ -931,7 +931,7 @@ void xen_enable_syscall(void)
{
int ret;

- ret = register_callback(CALLBACKTYPE_syscall, xen_syscall_target);
+ ret = register_callback(CALLBACKTYPE_syscall, xen_entry_SYSCALL_64);
if (ret != 0) {
printk(KERN_ERR "Failed to set syscall callback: %d\n", ret);
/* Pretty fatal; 64-bit userspace has no other
@@ -940,7 +940,7 @@ void xen_enable_syscall(void)

if (boot_cpu_has(X86_FEATURE_SYSCALL32)) {
ret = register_callback(CALLBACKTYPE_syscall32,
- xen_syscall32_target);
+ xen_entry_SYSCALL_compat);
if (ret != 0)
setup_clear_cpu_cap(X86_FEATURE_SYSCALL32);
}
diff --git a/arch/x86/xen/xen-asm.S b/arch/x86/xen/xen-asm.S
index 011ec649f388..e3031afcb103 100644
--- a/arch/x86/xen/xen-asm.S
+++ b/arch/x86/xen/xen-asm.S
@@ -14,6 +14,7 @@
#include <asm/thread_info.h>
#include <asm/asm.h>
#include <asm/frame.h>
+#include <asm/unwind_hints.h>

#include <xen/interface/xen.h>

@@ -44,7 +45,7 @@ SYM_FUNC_START(xen_irq_enable_direct)
call check_events
1:
FRAME_END
- ret
+ RET
SYM_FUNC_END(xen_irq_enable_direct)

@@ -54,7 +55,7 @@ SYM_FUNC_END(xen_irq_enable_direct)
*/
SYM_FUNC_START(xen_irq_disable_direct)
movb $1, PER_CPU_VAR(xen_vcpu_info) + XEN_vcpu_info_mask
- ret
+ RET
SYM_FUNC_END(xen_irq_disable_direct)

/*
@@ -70,7 +71,7 @@ SYM_FUNC_START(xen_save_fl_direct)
testb $0xff, PER_CPU_VAR(xen_vcpu_info) + XEN_vcpu_info_mask
setz %ah
addb %ah, %ah
- ret
+ RET
SYM_FUNC_END(xen_save_fl_direct)

@@ -97,7 +98,7 @@ SYM_FUNC_START(xen_restore_fl_direct)
call check_events
1:
FRAME_END
- ret
+ RET
SYM_FUNC_END(xen_restore_fl_direct)

@@ -127,7 +128,7 @@ SYM_FUNC_START(check_events)
pop %rcx
pop %rax
FRAME_END
- ret
+ RET
SYM_FUNC_END(check_events)

SYM_FUNC_START(xen_read_cr2)
@@ -135,18 +136,19 @@ SYM_FUNC_START(xen_read_cr2)
_ASM_MOV PER_CPU_VAR(xen_vcpu), %_ASM_AX
_ASM_MOV XEN_vcpu_info_arch_cr2(%_ASM_AX), %_ASM_AX
FRAME_END
- ret
+ RET
SYM_FUNC_END(xen_read_cr2);

SYM_FUNC_START(xen_read_cr2_direct)
FRAME_BEGIN
_ASM_MOV PER_CPU_VAR(xen_vcpu_info) + XEN_vcpu_info_arch_cr2, %_ASM_AX
FRAME_END
- ret
+ RET
SYM_FUNC_END(xen_read_cr2_direct);

.macro xen_pv_trap name
SYM_CODE_START(xen_\name)
+ UNWIND_HINT_ENTRY
pop %rcx
pop %r11
jmp \name
@@ -186,6 +188,7 @@ xen_pv_trap asm_exc_xen_hypervisor_callback
SYM_CODE_START(xen_early_idt_handler_array)
i = 0
.rept NUM_EXCEPTION_VECTORS
+ UNWIND_HINT_EMPTY
pop %rcx
pop %r11
jmp early_idt_handler_array + i*EARLY_IDT_HANDLER_SIZE
@@ -212,11 +215,13 @@ hypercall_iret = hypercall_page + __HYPERVISOR_iret * 32
* rsp->rax }
*/
SYM_CODE_START(xen_iret)
+ UNWIND_HINT_EMPTY
pushq $0
jmp hypercall_iret
SYM_CODE_END(xen_iret)

SYM_CODE_START(xen_sysret64)
+ UNWIND_HINT_EMPTY
/*
* We're already on the usermode stack at this point, but
* still with the kernel gs, so we can easily switch back.
@@ -271,7 +276,8 @@ SYM_CODE_END(xenpv_restore_regs_and_return_to_usermode)
*/

/* Normal 64-bit system call target */
-SYM_FUNC_START(xen_syscall_target)
+SYM_CODE_START(xen_entry_SYSCALL_64)
+ UNWIND_HINT_ENTRY
popq %rcx
popq %r11

@@ -284,12 +290,13 @@ SYM_FUNC_START(xen_syscall_target)
movq $__USER_CS, 1*8(%rsp)

jmp entry_SYSCALL_64_after_hwframe
-SYM_FUNC_END(xen_syscall_target)
+SYM_CODE_END(xen_entry_SYSCALL_64)

#ifdef CONFIG_IA32_EMULATION

/* 32-bit compat syscall target */
-SYM_FUNC_START(xen_syscall32_target)
+SYM_CODE_START(xen_entry_SYSCALL_compat)
+ UNWIND_HINT_ENTRY
popq %rcx
popq %r11

@@ -302,10 +309,11 @@ SYM_FUNC_START(xen_syscall32_target)
movq $__USER32_CS, 1*8(%rsp)

jmp entry_SYSCALL_compat_after_hwframe
-SYM_FUNC_END(xen_syscall32_target)
+SYM_CODE_END(xen_entry_SYSCALL_compat)

/* 32-bit compat sysenter target */
-SYM_FUNC_START(xen_sysenter_target)
+SYM_CODE_START(xen_entry_SYSENTER_compat)
+ UNWIND_HINT_ENTRY
/*
* NB: Xen is polite and clears TF from EFLAGS for us. This means
* that we don't need to guard against single step exceptions here.
@@ -322,17 +330,18 @@ SYM_FUNC_START(xen_sysenter_target)
movq $__USER32_CS, 1*8(%rsp)

jmp entry_SYSENTER_compat_after_hwframe
-SYM_FUNC_END(xen_sysenter_target)
+SYM_CODE_END(xen_entry_SYSENTER_compat)

#else /* !CONFIG_IA32_EMULATION */

-SYM_FUNC_START_ALIAS(xen_syscall32_target)
-SYM_FUNC_START(xen_sysenter_target)
+SYM_CODE_START(xen_entry_SYSCALL_compat)
+SYM_CODE_START(xen_entry_SYSENTER_compat)
+ UNWIND_HINT_ENTRY
lea 16(%rsp), %rsp /* strip %rcx, %r11 */
mov $-ENOSYS, %rax
pushq $0
jmp hypercall_iret
-SYM_FUNC_END(xen_sysenter_target)
-SYM_FUNC_END_ALIAS(xen_syscall32_target)
+SYM_CODE_END(xen_entry_SYSENTER_compat)
+SYM_CODE_END(xen_entry_SYSCALL_compat)

#endif /* CONFIG_IA32_EMULATION */
diff --git a/arch/x86/xen/xen-head.S b/arch/x86/xen/xen-head.S
index 2d7c8f34f56c..2a3ef5fcba34 100644
--- a/arch/x86/xen/xen-head.S
+++ b/arch/x86/xen/xen-head.S
@@ -68,8 +68,10 @@ SYM_CODE_END(asm_cpu_bringup_and_idle)
.balign PAGE_SIZE
SYM_CODE_START(hypercall_page)
.rept (PAGE_SIZE / 32)
- UNWIND_HINT_EMPTY
- .skip 32
+ UNWIND_HINT_FUNC
+ ANNOTATE_UNRET_SAFE
+ ret
+ .skip 31, 0xcc
.endr

#define HYPERCALL(n) \
diff --git a/arch/x86/xen/xen-ops.h b/arch/x86/xen/xen-ops.h
index 9546c3384c75..8695809b88f0 100644
--- a/arch/x86/xen/xen-ops.h
+++ b/arch/x86/xen/xen-ops.h
@@ -10,10 +10,10 @@
/* These are code, but not functions. Defined in entry.S */
extern const char xen_failsafe_callback[];

-void xen_sysenter_target(void);
+void xen_entry_SYSENTER_compat(void);
#ifdef CONFIG_X86_64
-void xen_syscall_target(void);
-void xen_syscall32_target(void);
+void xen_entry_SYSCALL_64(void);
+void xen_entry_SYSCALL_compat(void);
#endif

extern void *xen_initial_gdt;
diff --git a/drivers/base/cpu.c b/drivers/base/cpu.c
index 8ecb9f90f467..24dd532c8e5e 100644
--- a/drivers/base/cpu.c
+++ b/drivers/base/cpu.c
@@ -572,6 +572,12 @@ ssize_t __weak cpu_show_mmio_stale_data(struct device *dev,
return sysfs_emit(buf, "Not affected\n");
}

+ssize_t __weak cpu_show_retbleed(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ return sysfs_emit(buf, "Not affected\n");
+}
+
static DEVICE_ATTR(meltdown, 0444, cpu_show_meltdown, NULL);
static DEVICE_ATTR(spectre_v1, 0444, cpu_show_spectre_v1, NULL);
static DEVICE_ATTR(spectre_v2, 0444, cpu_show_spectre_v2, NULL);
@@ -582,6 +588,7 @@ static DEVICE_ATTR(tsx_async_abort, 0444, cpu_show_tsx_async_abort, NULL);
static DEVICE_ATTR(itlb_multihit, 0444, cpu_show_itlb_multihit, NULL);
static DEVICE_ATTR(srbds, 0444, cpu_show_srbds, NULL);
static DEVICE_ATTR(mmio_stale_data, 0444, cpu_show_mmio_stale_data, NULL);
+static DEVICE_ATTR(retbleed, 0444, cpu_show_retbleed, NULL);

static struct attribute *cpu_root_vulnerabilities_attrs[] = {
&dev_attr_meltdown.attr,
@@ -594,6 +601,7 @@ static struct attribute *cpu_root_vulnerabilities_attrs[] = {
&dev_attr_itlb_multihit.attr,
&dev_attr_srbds.attr,
&dev_attr_mmio_stale_data.attr,
+ &dev_attr_retbleed.attr,
NULL
};

diff --git a/drivers/idle/intel_idle.c b/drivers/idle/intel_idle.c
index d79335506ecd..b92b032fb6d1 100644
--- a/drivers/idle/intel_idle.c
+++ b/drivers/idle/intel_idle.c
@@ -47,11 +47,13 @@
#include <linux/tick.h>
#include <trace/events/power.h>
#include <linux/sched.h>
+#include <linux/sched/smt.h>
#include <linux/notifier.h>
#include <linux/cpu.h>
#include <linux/moduleparam.h>
#include <asm/cpu_device_id.h>
#include <asm/intel-family.h>
+#include <asm/nospec-branch.h>
#include <asm/mwait.h>
#include <asm/msr.h>

@@ -93,6 +95,12 @@ static unsigned int mwait_substates __initdata;
*/
#define CPUIDLE_FLAG_ALWAYS_ENABLE BIT(15)

+/*
+ * Disable IBRS across idle (when KERNEL_IBRS), is exclusive vs IRQ_ENABLE
+ * above.
+ */
+#define CPUIDLE_FLAG_IBRS BIT(16)
+
/*
* MWAIT takes an 8-bit "hint" in EAX "suggesting"
* the C-state (top nibble) and sub-state (bottom nibble)
@@ -132,6 +140,24 @@ static __cpuidle int intel_idle(struct cpuidle_device *dev,
return index;
}

+static __cpuidle int intel_idle_ibrs(struct cpuidle_device *dev,
+ struct cpuidle_driver *drv, int index)
+{
+ bool smt_active = sched_smt_active();
+ u64 spec_ctrl = spec_ctrl_current();
+ int ret;
+
+ if (smt_active)
+ wrmsrl(MSR_IA32_SPEC_CTRL, 0);
+
+ ret = intel_idle(dev, drv, index);
+
+ if (smt_active)
+ wrmsrl(MSR_IA32_SPEC_CTRL, spec_ctrl);
+
+ return ret;
+}
+
/**
* intel_idle_s2idle - Ask the processor to enter the given idle state.
* @dev: cpuidle device of the target CPU.
@@ -653,7 +679,7 @@ static struct cpuidle_state skl_cstates[] __initdata = {
{
.name = "C6",
.desc = "MWAIT 0x20",
- .flags = MWAIT2flg(0x20) | CPUIDLE_FLAG_TLB_FLUSHED,
+ .flags = MWAIT2flg(0x20) | CPUIDLE_FLAG_TLB_FLUSHED | CPUIDLE_FLAG_IBRS,
.exit_latency = 85,
.target_residency = 200,
.enter = &intel_idle,
@@ -661,7 +687,7 @@ static struct cpuidle_state skl_cstates[] __initdata = {
{
.name = "C7s",
.desc = "MWAIT 0x33",
- .flags = MWAIT2flg(0x33) | CPUIDLE_FLAG_TLB_FLUSHED,
+ .flags = MWAIT2flg(0x33) | CPUIDLE_FLAG_TLB_FLUSHED | CPUIDLE_FLAG_IBRS,
.exit_latency = 124,
.target_residency = 800,
.enter = &intel_idle,
@@ -669,7 +695,7 @@ static struct cpuidle_state skl_cstates[] __initdata = {
{
.name = "C8",
.desc = "MWAIT 0x40",
- .flags = MWAIT2flg(0x40) | CPUIDLE_FLAG_TLB_FLUSHED,
+ .flags = MWAIT2flg(0x40) | CPUIDLE_FLAG_TLB_FLUSHED | CPUIDLE_FLAG_IBRS,
.exit_latency = 200,
.target_residency = 800,
.enter = &intel_idle,
@@ -677,7 +703,7 @@ static struct cpuidle_state skl_cstates[] __initdata = {
{
.name = "C9",
.desc = "MWAIT 0x50",
- .flags = MWAIT2flg(0x50) | CPUIDLE_FLAG_TLB_FLUSHED,
+ .flags = MWAIT2flg(0x50) | CPUIDLE_FLAG_TLB_FLUSHED | CPUIDLE_FLAG_IBRS,
.exit_latency = 480,
.target_residency = 5000,
.enter = &intel_idle,
@@ -685,7 +711,7 @@ static struct cpuidle_state skl_cstates[] __initdata = {
{
.name = "C10",
.desc = "MWAIT 0x60",
- .flags = MWAIT2flg(0x60) | CPUIDLE_FLAG_TLB_FLUSHED,
+ .flags = MWAIT2flg(0x60) | CPUIDLE_FLAG_TLB_FLUSHED | CPUIDLE_FLAG_IBRS,
.exit_latency = 890,
.target_residency = 5000,
.enter = &intel_idle,
@@ -714,7 +740,7 @@ static struct cpuidle_state skx_cstates[] __initdata = {
{
.name = "C6",
.desc = "MWAIT 0x20",
- .flags = MWAIT2flg(0x20) | CPUIDLE_FLAG_TLB_FLUSHED,
+ .flags = MWAIT2flg(0x20) | CPUIDLE_FLAG_TLB_FLUSHED | CPUIDLE_FLAG_IBRS,
.exit_latency = 133,
.target_residency = 600,
.enter = &intel_idle,
@@ -1501,6 +1527,11 @@ static void __init intel_idle_init_cstates_icpu(struct cpuidle_driver *drv)
/* Structure copy. */
drv->states[drv->state_count] = cpuidle_state_table[cstate];

+ if (cpu_feature_enabled(X86_FEATURE_KERNEL_IBRS) &&
+ cpuidle_state_table[cstate].flags & CPUIDLE_FLAG_IBRS) {
+ drv->states[drv->state_count].enter = intel_idle_ibrs;
+ }
+
if ((disabled_states_mask & BIT(drv->state_count)) ||
((icpu->use_acpi || force_use_acpi) &&
intel_idle_off_by_default(mwait_hint) &&
diff --git a/include/linux/cpu.h b/include/linux/cpu.h
index d63b8f70d123..24e5f237244d 100644
--- a/include/linux/cpu.h
+++ b/include/linux/cpu.h
@@ -68,6 +68,8 @@ extern ssize_t cpu_show_srbds(struct device *dev, struct device_attribute *attr,
extern ssize_t cpu_show_mmio_stale_data(struct device *dev,
struct device_attribute *attr,
char *buf);
+extern ssize_t cpu_show_retbleed(struct device *dev,
+ struct device_attribute *attr, char *buf);

extern __printf(4, 5)
struct device *cpu_device_create(struct device *parent, void *drvdata,
diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index c66c702a4f07..439fbe0ee0c7 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -988,7 +988,7 @@ static inline void kvm_arch_end_assignment(struct kvm *kvm)
{
}

-static inline bool kvm_arch_has_assigned_device(struct kvm *kvm)
+static __always_inline bool kvm_arch_has_assigned_device(struct kvm *kvm)
{
return false;
}
diff --git a/include/linux/objtool.h b/include/linux/objtool.h
index 577f51436cf9..662f19374bd9 100644
--- a/include/linux/objtool.h
+++ b/include/linux/objtool.h
@@ -29,11 +29,19 @@ struct unwind_hint {
*
* UNWIND_HINT_TYPE_REGS_PARTIAL: Used in entry code to indicate that
* sp_reg+sp_offset points to the iret return frame.
+ *
+ * UNWIND_HINT_FUNC: Generate the unwind metadata of a callable function.
+ * Useful for code which doesn't have an ELF function annotation.
+ *
+ * UNWIND_HINT_ENTRY: machine entry without stack, SYSCALL/SYSENTER etc.
*/
#define UNWIND_HINT_TYPE_CALL 0
#define UNWIND_HINT_TYPE_REGS 1
#define UNWIND_HINT_TYPE_REGS_PARTIAL 2
-#define UNWIND_HINT_TYPE_RET_OFFSET 3
+#define UNWIND_HINT_TYPE_FUNC 3
+#define UNWIND_HINT_TYPE_ENTRY 4
+#define UNWIND_HINT_TYPE_SAVE 5
+#define UNWIND_HINT_TYPE_RESTORE 6

#ifdef CONFIG_STACK_VALIDATION

@@ -96,7 +104,7 @@ struct unwind_hint {
* the debuginfo as necessary. It will also warn if it sees any
* inconsistencies.
*/
-.macro UNWIND_HINT sp_reg:req sp_offset=0 type:req end=0
+.macro UNWIND_HINT type:req sp_reg=0 sp_offset=0 end=0
.Lunwind_hint_ip_\@:
.pushsection .discard.unwind_hints
/* struct unwind_hint */
@@ -120,7 +128,7 @@ struct unwind_hint {
#define STACK_FRAME_NON_STANDARD(func)
#else
#define ANNOTATE_INTRA_FUNCTION_CALL
-.macro UNWIND_HINT sp_reg:req sp_offset=0 type:req end=0
+.macro UNWIND_HINT type:req sp_reg=0 sp_offset=0 end=0
.endm
#endif

diff --git a/samples/ftrace/ftrace-direct-modify.c b/samples/ftrace/ftrace-direct-modify.c
index 89e6bf27cd9f..d620f3da086f 100644
--- a/samples/ftrace/ftrace-direct-modify.c
+++ b/samples/ftrace/ftrace-direct-modify.c
@@ -31,7 +31,7 @@ asm (
" call my_direct_func1\n"
" leave\n"
" .size my_tramp1, .-my_tramp1\n"
-" ret\n"
+ ASM_RET
" .type my_tramp2, @function\n"
" .globl my_tramp2\n"
" my_tramp2:"
@@ -39,7 +39,7 @@ asm (
" movq %rsp, %rbp\n"
" call my_direct_func2\n"
" leave\n"
-" ret\n"
+ ASM_RET
" .size my_tramp2, .-my_tramp2\n"
" .popsection\n"
);
diff --git a/samples/ftrace/ftrace-direct-too.c b/samples/ftrace/ftrace-direct-too.c
index 11b99325f3db..3927cb880d1a 100644
--- a/samples/ftrace/ftrace-direct-too.c
+++ b/samples/ftrace/ftrace-direct-too.c
@@ -31,7 +31,7 @@ asm (
" popq %rsi\n"
" popq %rdi\n"
" leave\n"
-" ret\n"
+ ASM_RET
" .size my_tramp, .-my_tramp\n"
" .popsection\n"
);
diff --git a/samples/ftrace/ftrace-direct.c b/samples/ftrace/ftrace-direct.c
index 642c50b5f716..1e901bb8d729 100644
--- a/samples/ftrace/ftrace-direct.c
+++ b/samples/ftrace/ftrace-direct.c
@@ -24,7 +24,7 @@ asm (
" call my_direct_func\n"
" popq %rdi\n"
" leave\n"
-" ret\n"
+ ASM_RET
" .size my_tramp, .-my_tramp\n"
" .popsection\n"
);
diff --git a/scripts/Makefile.build b/scripts/Makefile.build
index 8bd4e673383f..17e8b2065900 100644
--- a/scripts/Makefile.build
+++ b/scripts/Makefile.build
@@ -227,9 +227,15 @@ endif
ifdef CONFIG_RETPOLINE
objtool_args += --retpoline
endif
+ifdef CONFIG_RETHUNK
+ objtool_args += --rethunk
+endif
ifdef CONFIG_X86_SMAP
objtool_args += --uaccess
endif
+ifdef CONFIG_SLS
+ objtool_args += --sls
+endif

# 'OBJECT_FILES_NON_STANDARD := y': skip objtool checking for a directory
# 'OBJECT_FILES_NON_STANDARD_foo.o := 'y': skip objtool checking for a file
diff --git a/scripts/link-vmlinux.sh b/scripts/link-vmlinux.sh
index 6eded325c837..d0b44bee9286 100755
--- a/scripts/link-vmlinux.sh
+++ b/scripts/link-vmlinux.sh
@@ -65,6 +65,9 @@ objtool_link()

if [ -n "${CONFIG_VMLINUX_VALIDATION}" ]; then
objtoolopt="check"
+ if [ -n "${CONFIG_CPU_UNRET_ENTRY}" ]; then
+ objtoolopt="${objtoolopt} --unret"
+ fi
if [ -z "${CONFIG_FRAME_POINTER}" ]; then
objtoolopt="${objtoolopt} --no-fp"
fi
@@ -77,6 +80,9 @@ objtool_link()
if [ -n "${CONFIG_X86_SMAP}" ]; then
objtoolopt="${objtoolopt} --uaccess"
fi
+ if [ -n "${CONFIG_SLS}" ]; then
+ objtoolopt="${objtoolopt} --sls"
+ fi
info OBJTOOL ${1}
tools/objtool/objtool ${objtoolopt} ${1}
fi
diff --git a/security/Kconfig b/security/Kconfig
index 0548db16c49d..9893c316da89 100644
--- a/security/Kconfig
+++ b/security/Kconfig
@@ -54,17 +54,6 @@ config SECURITY_NETWORK
implement socket and networking access controls.
If you are unsure how to answer this question, answer N.

-config PAGE_TABLE_ISOLATION
- bool "Remove the kernel mapping in user mode"
- default y
- depends on (X86_64 || X86_PAE) && !UML
- help
- This feature reduces the number of hardware side channels by
- ensuring that the majority of kernel addresses are not mapped
- into userspace.
-
- See Documentation/x86/pti.rst for more details.
-
config SECURITY_INFINIBAND
bool "Infiniband Security Hooks"
depends on SECURITY && INFINIBAND
diff --git a/tools/arch/x86/include/asm/cpufeatures.h b/tools/arch/x86/include/asm/cpufeatures.h
index a7b5c5efcf3b..54ba20492ad1 100644
--- a/tools/arch/x86/include/asm/cpufeatures.h
+++ b/tools/arch/x86/include/asm/cpufeatures.h
@@ -203,8 +203,8 @@
#define X86_FEATURE_PROC_FEEDBACK ( 7*32+ 9) /* AMD ProcFeedbackInterface */
#define X86_FEATURE_SME ( 7*32+10) /* AMD Secure Memory Encryption */
#define X86_FEATURE_PTI ( 7*32+11) /* Kernel Page Table Isolation enabled */
-#define X86_FEATURE_RETPOLINE ( 7*32+12) /* "" Generic Retpoline mitigation for Spectre variant 2 */
-#define X86_FEATURE_RETPOLINE_LFENCE ( 7*32+13) /* "" Use LFENCEs for Spectre variant 2 */
+#define X86_FEATURE_KERNEL_IBRS ( 7*32+12) /* "" Set/clear IBRS on kernel entry/exit */
+#define X86_FEATURE_RSB_VMEXIT ( 7*32+13) /* "" Fill RSB on VM-Exit */
#define X86_FEATURE_INTEL_PPIN ( 7*32+14) /* Intel Processor Inventory Number */
#define X86_FEATURE_CDP_L2 ( 7*32+15) /* Code and Data Prioritization L2 */
#define X86_FEATURE_MSR_SPEC_CTRL ( 7*32+16) /* "" MSR SPEC_CTRL is implemented */
@@ -290,6 +290,12 @@
#define X86_FEATURE_FENCE_SWAPGS_KERNEL (11*32+ 5) /* "" LFENCE in kernel entry SWAPGS path */
#define X86_FEATURE_SPLIT_LOCK_DETECT (11*32+ 6) /* #AC for split lock */
#define X86_FEATURE_PER_THREAD_MBA (11*32+ 7) /* "" Per-thread Memory Bandwidth Allocation */
+#define X86_FEATURE_ENTRY_IBPB (11*32+10) /* "" Issue an IBPB on kernel entry */
+#define X86_FEATURE_RRSBA_CTRL (11*32+11) /* "" RET prediction control */
+#define X86_FEATURE_RETPOLINE (11*32+12) /* "" Generic Retpoline mitigation for Spectre variant 2 */
+#define X86_FEATURE_RETPOLINE_LFENCE (11*32+13) /* "" Use LFENCE for Spectre variant 2 */
+#define X86_FEATURE_RETHUNK (11*32+14) /* "" Use REturn THUNK */
+#define X86_FEATURE_UNRET (11*32+15) /* "" AMD BTB untrain return */

/* Intel-defined CPU features, CPUID level 0x00000007:1 (EAX), word 12 */
#define X86_FEATURE_AVX512_BF16 (12*32+ 5) /* AVX512 BFLOAT16 instructions */
@@ -308,6 +314,7 @@
#define X86_FEATURE_AMD_SSBD (13*32+24) /* "" Speculative Store Bypass Disable */
#define X86_FEATURE_VIRT_SSBD (13*32+25) /* Virtualized Speculative Store Bypass Disable */
#define X86_FEATURE_AMD_SSB_NO (13*32+26) /* "" Speculative Store Bypass is fixed in hardware. */
+#define X86_FEATURE_BTC_NO (13*32+29) /* "" Not vulnerable to Branch Type Confusion */

/* Thermal and Power Management Leaf, CPUID level 0x00000006 (EAX), word 14 */
#define X86_FEATURE_DTHERM (14*32+ 0) /* Digital Thermal Sensor */
@@ -418,5 +425,6 @@
#define X86_BUG_ITLB_MULTIHIT X86_BUG(23) /* CPU may incur MCE during certain page attribute changes */
#define X86_BUG_SRBDS X86_BUG(24) /* CPU may leak RNG bits if not mitigated */
#define X86_BUG_MMIO_STALE_DATA X86_BUG(25) /* CPU is affected by Processor MMIO Stale Data vulnerabilities */
+#define X86_BUG_RETBLEED X86_BUG(26) /* CPU is affected by RETBleed */

#endif /* _ASM_X86_CPUFEATURES_H */
diff --git a/tools/arch/x86/include/asm/disabled-features.h b/tools/arch/x86/include/asm/disabled-features.h
index 5861d34f9771..d109c5ec967c 100644
--- a/tools/arch/x86/include/asm/disabled-features.h
+++ b/tools/arch/x86/include/asm/disabled-features.h
@@ -56,6 +56,25 @@
# define DISABLE_PTI (1 << (X86_FEATURE_PTI & 31))
#endif

+#ifdef CONFIG_RETPOLINE
+# define DISABLE_RETPOLINE 0
+#else
+# define DISABLE_RETPOLINE ((1 << (X86_FEATURE_RETPOLINE & 31)) | \
+ (1 << (X86_FEATURE_RETPOLINE_LFENCE & 31)))
+#endif
+
+#ifdef CONFIG_RETHUNK
+# define DISABLE_RETHUNK 0
+#else
+# define DISABLE_RETHUNK (1 << (X86_FEATURE_RETHUNK & 31))
+#endif
+
+#ifdef CONFIG_CPU_UNRET_ENTRY
+# define DISABLE_UNRET 0
+#else
+# define DISABLE_UNRET (1 << (X86_FEATURE_UNRET & 31))
+#endif
+
#ifdef CONFIG_IOMMU_SUPPORT
# define DISABLE_ENQCMD 0
#else
@@ -76,7 +95,7 @@
#define DISABLED_MASK8 0
#define DISABLED_MASK9 (DISABLE_SMAP)
#define DISABLED_MASK10 0
-#define DISABLED_MASK11 0
+#define DISABLED_MASK11 (DISABLE_RETPOLINE|DISABLE_RETHUNK|DISABLE_UNRET)
#define DISABLED_MASK12 0
#define DISABLED_MASK13 0
#define DISABLED_MASK14 0
diff --git a/tools/arch/x86/include/asm/inat.h b/tools/arch/x86/include/asm/inat.h
index 877827b7c2c3..a61051400311 100644
--- a/tools/arch/x86/include/asm/inat.h
+++ b/tools/arch/x86/include/asm/inat.h
@@ -6,7 +6,7 @@
*
* Written by Masami Hiramatsu <mhiramat@redhat.com>
*/
-#include "inat_types.h"
+#include "inat_types.h" /* __ignore_sync_check__ */

/*
* Internal bits. Don't use bitmasks directly, because these bits are
diff --git a/tools/arch/x86/include/asm/insn.h b/tools/arch/x86/include/asm/insn.h
index 52c6262e6bfd..636ec02793a7 100644
--- a/tools/arch/x86/include/asm/insn.h
+++ b/tools/arch/x86/include/asm/insn.h
@@ -8,7 +8,7 @@
*/

/* insn_attr_t is defined in inat.h */
-#include "inat.h"
+#include "inat.h" /* __ignore_sync_check__ */

struct insn_field {
union {
@@ -87,13 +87,25 @@ struct insn {
#define X86_VEX_M_MAX 0x1f /* VEX3.M Maximum value */

extern void insn_init(struct insn *insn, const void *kaddr, int buf_len, int x86_64);
-extern void insn_get_prefixes(struct insn *insn);
-extern void insn_get_opcode(struct insn *insn);
-extern void insn_get_modrm(struct insn *insn);
-extern void insn_get_sib(struct insn *insn);
-extern void insn_get_displacement(struct insn *insn);
-extern void insn_get_immediate(struct insn *insn);
-extern void insn_get_length(struct insn *insn);
+extern int insn_get_prefixes(struct insn *insn);
+extern int insn_get_opcode(struct insn *insn);
+extern int insn_get_modrm(struct insn *insn);
+extern int insn_get_sib(struct insn *insn);
+extern int insn_get_displacement(struct insn *insn);
+extern int insn_get_immediate(struct insn *insn);
+extern int insn_get_length(struct insn *insn);
+
+enum insn_mode {
+ INSN_MODE_32,
+ INSN_MODE_64,
+ /* Mode is determined by the current kernel build. */
+ INSN_MODE_KERN,
+ INSN_NUM_MODES,
+};
+
+extern int insn_decode(struct insn *insn, const void *kaddr, int buf_len, enum insn_mode m);
+
+#define insn_decode_kernel(_insn, _ptr) insn_decode((_insn), (_ptr), MAX_INSN_SIZE, INSN_MODE_KERN)

/* Attribute will be determined after getting ModRM (for opcode groups) */
static inline void insn_get_attribute(struct insn *insn)
diff --git a/tools/arch/x86/include/asm/msr-index.h b/tools/arch/x86/include/asm/msr-index.h
index 96973d197972..407de670cd60 100644
--- a/tools/arch/x86/include/asm/msr-index.h
+++ b/tools/arch/x86/include/asm/msr-index.h
@@ -51,6 +51,8 @@
#define SPEC_CTRL_STIBP BIT(SPEC_CTRL_STIBP_SHIFT) /* STIBP mask */
#define SPEC_CTRL_SSBD_SHIFT 2 /* Speculative Store Bypass Disable bit */
#define SPEC_CTRL_SSBD BIT(SPEC_CTRL_SSBD_SHIFT) /* Speculative Store Bypass Disable */
+#define SPEC_CTRL_RRSBA_DIS_S_SHIFT 6 /* Disable RRSBA behavior */
+#define SPEC_CTRL_RRSBA_DIS_S BIT(SPEC_CTRL_RRSBA_DIS_S_SHIFT)

#define MSR_IA32_PRED_CMD 0x00000049 /* Prediction Command */
#define PRED_CMD_IBPB BIT(0) /* Indirect Branch Prediction Barrier */
@@ -91,6 +93,7 @@
#define MSR_IA32_ARCH_CAPABILITIES 0x0000010a
#define ARCH_CAP_RDCL_NO BIT(0) /* Not susceptible to Meltdown */
#define ARCH_CAP_IBRS_ALL BIT(1) /* Enhanced IBRS support */
+#define ARCH_CAP_RSBA BIT(2) /* RET may use alternative branch predictors */
#define ARCH_CAP_SKIP_VMENTRY_L1DFLUSH BIT(3) /* Skip L1D flush on vmentry */
#define ARCH_CAP_SSB_NO BIT(4) /*
* Not susceptible to Speculative Store Bypass
@@ -138,6 +141,13 @@
* bit available to control VERW
* behavior.
*/
+#define ARCH_CAP_RRSBA BIT(19) /*
+ * Indicates RET may use predictors
+ * other than the RSB. With eIBRS
+ * enabled predictions in kernel mode
+ * are restricted to targets in
+ * kernel.
+ */

#define MSR_IA32_FLUSH_CMD 0x0000010b
#define L1D_FLUSH BIT(0) /*
@@ -507,6 +517,9 @@
/* Fam 17h MSRs */
#define MSR_F17H_IRPERF 0xc00000e9

+#define MSR_ZEN2_SPECTRAL_CHICKEN 0xc00110e3
+#define MSR_ZEN2_SPECTRAL_CHICKEN_BIT BIT_ULL(1)
+
/* Fam 16h MSRs */
#define MSR_F16H_L2I_PERF_CTL 0xc0010230
#define MSR_F16H_L2I_PERF_CTR 0xc0010231
diff --git a/tools/arch/x86/lib/inat.c b/tools/arch/x86/lib/inat.c
index 4f5ed49e1b4e..dfbcc6405941 100644
--- a/tools/arch/x86/lib/inat.c
+++ b/tools/arch/x86/lib/inat.c
@@ -4,7 +4,7 @@
*
* Written by Masami Hiramatsu <mhiramat@redhat.com>
*/
-#include "../include/asm/insn.h"
+#include "../include/asm/insn.h" /* __ignore_sync_check__ */

/* Attribute tables are generated from opcode map */
#include "inat-tables.c"
diff --git a/tools/arch/x86/lib/insn.c b/tools/arch/x86/lib/insn.c
index 0151dfc6da61..f24cc0f618e4 100644
--- a/tools/arch/x86/lib/insn.c
+++ b/tools/arch/x86/lib/insn.c
@@ -10,10 +10,13 @@
#else
#include <string.h>
#endif
-#include "../include/asm/inat.h"
-#include "../include/asm/insn.h"
+#include "../include/asm/inat.h" /* __ignore_sync_check__ */
+#include "../include/asm/insn.h" /* __ignore_sync_check__ */

-#include "../include/asm/emulate_prefix.h"
+#include <linux/errno.h>
+#include <linux/kconfig.h>
+
+#include "../include/asm/emulate_prefix.h" /* __ignore_sync_check__ */

/* Verify next sizeof(t) bytes can be on the same instruction */
#define validate_next(t, insn, n) \
@@ -97,8 +100,12 @@ static void insn_get_emulate_prefix(struct insn *insn)
* Populates the @insn->prefixes bitmap, and updates @insn->next_byte
* to point to the (first) opcode. No effect if @insn->prefixes.got
* is already set.
+ *
+ * * Returns:
+ * 0: on success
+ * < 0: on error
*/
-void insn_get_prefixes(struct insn *insn)
+int insn_get_prefixes(struct insn *insn)
{
struct insn_field *prefixes = &insn->prefixes;
insn_attr_t attr;
@@ -106,7 +113,7 @@ void insn_get_prefixes(struct insn *insn)
int i, nb;

if (prefixes->got)
- return;
+ return 0;

insn_get_emulate_prefix(insn);

@@ -217,8 +224,10 @@ void insn_get_prefixes(struct insn *insn)

prefixes->got = 1;

+ return 0;
+
err_out:
- return;
+ return -ENODATA;
}

/**
@@ -230,16 +239,25 @@ void insn_get_prefixes(struct insn *insn)
* If necessary, first collects any preceding (prefix) bytes.
* Sets @insn->opcode.value = opcode1. No effect if @insn->opcode.got
* is already 1.
+ *
+ * Returns:
+ * 0: on success
+ * < 0: on error
*/
-void insn_get_opcode(struct insn *insn)
+int insn_get_opcode(struct insn *insn)
{
struct insn_field *opcode = &insn->opcode;
+ int pfx_id, ret;
insn_byte_t op;
- int pfx_id;
+
if (opcode->got)
- return;
- if (!insn->prefixes.got)
- insn_get_prefixes(insn);
+ return 0;
+
+ if (!insn->prefixes.got) {
+ ret = insn_get_prefixes(insn);
+ if (ret)
+ return ret;
+ }

/* Get first opcode */
op = get_next(insn_byte_t, insn);
@@ -254,9 +272,13 @@ void insn_get_opcode(struct insn *insn)
insn->attr = inat_get_avx_attribute(op, m, p);
if ((inat_must_evex(insn->attr) && !insn_is_evex(insn)) ||
(!inat_accept_vex(insn->attr) &&
- !inat_is_group(insn->attr)))
- insn->attr = 0; /* This instruction is bad */
- goto end; /* VEX has only 1 byte for opcode */
+ !inat_is_group(insn->attr))) {
+ /* This instruction is bad */
+ insn->attr = 0;
+ return -EINVAL;
+ }
+ /* VEX has only 1 byte for opcode */
+ goto end;
}

insn->attr = inat_get_opcode_attribute(op);
@@ -267,13 +289,18 @@ void insn_get_opcode(struct insn *insn)
pfx_id = insn_last_prefix_id(insn);
insn->attr = inat_get_escape_attribute(op, pfx_id, insn->attr);
}
- if (inat_must_vex(insn->attr))
- insn->attr = 0; /* This instruction is bad */
+
+ if (inat_must_vex(insn->attr)) {
+ /* This instruction is bad */
+ insn->attr = 0;
+ return -EINVAL;
+ }
end:
opcode->got = 1;
+ return 0;

err_out:
- return;
+ return -ENODATA;
}

/**
@@ -283,15 +310,25 @@ void insn_get_opcode(struct insn *insn)
* Populates @insn->modrm and updates @insn->next_byte to point past the
* ModRM byte, if any. If necessary, first collects the preceding bytes
* (prefixes and opcode(s)). No effect if @insn->modrm.got is already 1.
+ *
+ * Returns:
+ * 0: on success
+ * < 0: on error
*/
-void insn_get_modrm(struct insn *insn)
+int insn_get_modrm(struct insn *insn)
{
struct insn_field *modrm = &insn->modrm;
insn_byte_t pfx_id, mod;
+ int ret;
+
if (modrm->got)
- return;
- if (!insn->opcode.got)
- insn_get_opcode(insn);
+ return 0;
+
+ if (!insn->opcode.got) {
+ ret = insn_get_opcode(insn);
+ if (ret)
+ return ret;
+ }

if (inat_has_modrm(insn->attr)) {
mod = get_next(insn_byte_t, insn);
@@ -301,17 +338,22 @@ void insn_get_modrm(struct insn *insn)
pfx_id = insn_last_prefix_id(insn);
insn->attr = inat_get_group_attribute(mod, pfx_id,
insn->attr);
- if (insn_is_avx(insn) && !inat_accept_vex(insn->attr))
- insn->attr = 0; /* This is bad */
+ if (insn_is_avx(insn) && !inat_accept_vex(insn->attr)) {
+ /* Bad insn */
+ insn->attr = 0;
+ return -EINVAL;
+ }
}
}

if (insn->x86_64 && inat_is_force64(insn->attr))
insn->opnd_bytes = 8;
+
modrm->got = 1;
+ return 0;

err_out:
- return;
+ return -ENODATA;
}

@@ -325,11 +367,16 @@ void insn_get_modrm(struct insn *insn)
int insn_rip_relative(struct insn *insn)
{
struct insn_field *modrm = &insn->modrm;
+ int ret;

if (!insn->x86_64)
return 0;
- if (!modrm->got)
- insn_get_modrm(insn);
+
+ if (!modrm->got) {
+ ret = insn_get_modrm(insn);
+ if (ret)
+ return 0;
+ }
/*
* For rip-relative instructions, the mod field (top 2 bits)
* is zero and the r/m field (bottom 3 bits) is 0x5.
@@ -343,15 +390,25 @@ int insn_rip_relative(struct insn *insn)
*
* If necessary, first collects the instruction up to and including the
* ModRM byte.
+ *
+ * Returns:
+ * 0: if decoding succeeded
+ * < 0: otherwise.
*/
-void insn_get_sib(struct insn *insn)
+int insn_get_sib(struct insn *insn)
{
insn_byte_t modrm;
+ int ret;

if (insn->sib.got)
- return;
- if (!insn->modrm.got)
- insn_get_modrm(insn);
+ return 0;
+
+ if (!insn->modrm.got) {
+ ret = insn_get_modrm(insn);
+ if (ret)
+ return ret;
+ }
+
if (insn->modrm.nbytes) {
modrm = (insn_byte_t)insn->modrm.value;
if (insn->addr_bytes != 2 &&
@@ -362,8 +419,10 @@ void insn_get_sib(struct insn *insn)
}
insn->sib.got = 1;

+ return 0;
+
err_out:
- return;
+ return -ENODATA;
}

@@ -374,15 +433,25 @@ void insn_get_sib(struct insn *insn)
* If necessary, first collects the instruction up to and including the
* SIB byte.
* Displacement value is sign-expanded.
+ *
+ * * Returns:
+ * 0: if decoding succeeded
+ * < 0: otherwise.
*/
-void insn_get_displacement(struct insn *insn)
+int insn_get_displacement(struct insn *insn)
{
insn_byte_t mod, rm, base;
+ int ret;

if (insn->displacement.got)
- return;
- if (!insn->sib.got)
- insn_get_sib(insn);
+ return 0;
+
+ if (!insn->sib.got) {
+ ret = insn_get_sib(insn);
+ if (ret)
+ return ret;
+ }
+
if (insn->modrm.nbytes) {
/*
* Interpreting the modrm byte:
@@ -425,9 +494,10 @@ void insn_get_displacement(struct insn *insn)
}
out:
insn->displacement.got = 1;
+ return 0;

err_out:
- return;
+ return -ENODATA;
}

/* Decode moffset16/32/64. Return 0 if failed */
@@ -538,20 +608,30 @@ static int __get_immptr(struct insn *insn)
}

/**
- * insn_get_immediate() - Get the immediates of instruction
+ * insn_get_immediate() - Get the immediate in an instruction
* @insn: &struct insn containing instruction
*
* If necessary, first collects the instruction up to and including the
* displacement bytes.
* Basically, most of immediates are sign-expanded. Unsigned-value can be
- * get by bit masking with ((1 << (nbytes * 8)) - 1)
+ * computed by bit masking with ((1 << (nbytes * 8)) - 1)
+ *
+ * Returns:
+ * 0: on success
+ * < 0: on error
*/
-void insn_get_immediate(struct insn *insn)
+int insn_get_immediate(struct insn *insn)
{
+ int ret;
+
if (insn->immediate.got)
- return;
- if (!insn->displacement.got)
- insn_get_displacement(insn);
+ return 0;
+
+ if (!insn->displacement.got) {
+ ret = insn_get_displacement(insn);
+ if (ret)
+ return ret;
+ }

if (inat_has_moffset(insn->attr)) {
if (!__get_moffset(insn))
@@ -604,9 +684,10 @@ void insn_get_immediate(struct insn *insn)
}
done:
insn->immediate.got = 1;
+ return 0;

err_out:
- return;
+ return -ENODATA;
}

/**
@@ -615,13 +696,58 @@ void insn_get_immediate(struct insn *insn)
*
* If necessary, first collects the instruction up to and including the
* immediates bytes.
- */
-void insn_get_length(struct insn *insn)
+ *
+ * Returns:
+ * - 0 on success
+ * - < 0 on error
+*/
+int insn_get_length(struct insn *insn)
{
+ int ret;
+
if (insn->length)
- return;
- if (!insn->immediate.got)
- insn_get_immediate(insn);
+ return 0;
+
+ if (!insn->immediate.got) {
+ ret = insn_get_immediate(insn);
+ if (ret)
+ return ret;
+ }
+
insn->length = (unsigned char)((unsigned long)insn->next_byte
- (unsigned long)insn->kaddr);
+
+ return 0;
+}
+
+/**
+ * insn_decode() - Decode an x86 instruction
+ * @insn: &struct insn to be initialized
+ * @kaddr: address (in kernel memory) of instruction (or copy thereof)
+ * @buf_len: length of the insn buffer at @kaddr
+ * @m: insn mode, see enum insn_mode
+ *
+ * Returns:
+ * 0: if decoding succeeded
+ * < 0: otherwise.
+ */
+int insn_decode(struct insn *insn, const void *kaddr, int buf_len, enum insn_mode m)
+{
+ int ret;
+
+#define INSN_MODE_KERN (enum insn_mode)-1 /* __ignore_sync_check__ mode is only valid in the kernel */
+
+ if (m == INSN_MODE_KERN)
+ insn_init(insn, kaddr, buf_len, IS_ENABLED(CONFIG_X86_64));
+ else
+ insn_init(insn, kaddr, buf_len, m == INSN_MODE_64);
+
+ ret = insn_get_length(insn);
+ if (ret)
+ return ret;
+
+ if (insn_complete(insn))
+ return 0;
+
+ return -EINVAL;
}
diff --git a/tools/arch/x86/lib/memcpy_64.S b/tools/arch/x86/lib/memcpy_64.S
index 1e299ac73c86..59cf2343f3d9 100644
--- a/tools/arch/x86/lib/memcpy_64.S
+++ b/tools/arch/x86/lib/memcpy_64.S
@@ -4,7 +4,7 @@
#include <linux/linkage.h>
#include <asm/errno.h>
#include <asm/cpufeatures.h>
-#include <asm/alternative-asm.h>
+#include <asm/alternative.h>
#include <asm/export.h>

.pushsection .noinstr.text, "ax"
@@ -39,7 +39,7 @@ SYM_FUNC_START_WEAK(memcpy)
rep movsq
movl %edx, %ecx
rep movsb
- ret
+ RET
SYM_FUNC_END(memcpy)
SYM_FUNC_END_ALIAS(__memcpy)
EXPORT_SYMBOL(memcpy)
@@ -53,7 +53,7 @@ SYM_FUNC_START_LOCAL(memcpy_erms)
movq %rdi, %rax
movq %rdx, %rcx
rep movsb
- ret
+ RET
SYM_FUNC_END(memcpy_erms)

SYM_FUNC_START_LOCAL(memcpy_orig)
@@ -137,7 +137,7 @@ SYM_FUNC_START_LOCAL(memcpy_orig)
movq %r9, 1*8(%rdi)
movq %r10, -2*8(%rdi, %rdx)
movq %r11, -1*8(%rdi, %rdx)
- retq
+ RET
.p2align 4
.Lless_16bytes:
cmpl $8, %edx
@@ -149,7 +149,7 @@ SYM_FUNC_START_LOCAL(memcpy_orig)
movq -1*8(%rsi, %rdx), %r9
movq %r8, 0*8(%rdi)
movq %r9, -1*8(%rdi, %rdx)
- retq
+ RET
.p2align 4
.Lless_8bytes:
cmpl $4, %edx
@@ -162,7 +162,7 @@ SYM_FUNC_START_LOCAL(memcpy_orig)
movl -4(%rsi, %rdx), %r8d
movl %ecx, (%rdi)
movl %r8d, -4(%rdi, %rdx)
- retq
+ RET
.p2align 4
.Lless_3bytes:
subl $1, %edx
@@ -180,7 +180,7 @@ SYM_FUNC_START_LOCAL(memcpy_orig)
movb %cl, (%rdi)

.Lend:
- retq
+ RET
SYM_FUNC_END(memcpy_orig)

.popsection
diff --git a/tools/arch/x86/lib/memset_64.S b/tools/arch/x86/lib/memset_64.S
index 0bfd26e4ca9e..d624f2bc42f1 100644
--- a/tools/arch/x86/lib/memset_64.S
+++ b/tools/arch/x86/lib/memset_64.S
@@ -3,7 +3,7 @@

#include <linux/linkage.h>
#include <asm/cpufeatures.h>
-#include <asm/alternative-asm.h>
+#include <asm/alternative.h>
#include <asm/export.h>

/*
@@ -40,7 +40,7 @@ SYM_FUNC_START(__memset)
movl %edx,%ecx
rep stosb
movq %r9,%rax
- ret
+ RET
SYM_FUNC_END(__memset)
SYM_FUNC_END_ALIAS(memset)
EXPORT_SYMBOL(memset)
@@ -63,7 +63,7 @@ SYM_FUNC_START_LOCAL(memset_erms)
movq %rdx,%rcx
rep stosb
movq %r9,%rax
- ret
+ RET
SYM_FUNC_END(memset_erms)

SYM_FUNC_START_LOCAL(memset_orig)
@@ -125,7 +125,7 @@ SYM_FUNC_START_LOCAL(memset_orig)

.Lende:
movq %r10,%rax
- ret
+ RET

.Lbad_alignment:
cmpq $7,%rdx
diff --git a/tools/include/asm/alternative-asm.h b/tools/include/asm/alternative-asm.h
deleted file mode 100644
index b54bd860dff6..000000000000
--- a/tools/include/asm/alternative-asm.h
+++ /dev/null
@@ -1,10 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0 */
-#ifndef _TOOLS_ASM_ALTERNATIVE_ASM_H
-#define _TOOLS_ASM_ALTERNATIVE_ASM_H
-
-/* Just disable it so we can build arch/x86/lib/memcpy_64.S for perf bench: */
-
-#define altinstruction_entry #
-#define ALTERNATIVE_2 #
-
-#endif
diff --git a/tools/include/asm/alternative.h b/tools/include/asm/alternative.h
new file mode 100644
index 000000000000..b54bd860dff6
--- /dev/null
+++ b/tools/include/asm/alternative.h
@@ -0,0 +1,10 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _TOOLS_ASM_ALTERNATIVE_ASM_H
+#define _TOOLS_ASM_ALTERNATIVE_ASM_H
+
+/* Just disable it so we can build arch/x86/lib/memcpy_64.S for perf bench: */
+
+#define altinstruction_entry #
+#define ALTERNATIVE_2 #
+
+#endif
diff --git a/tools/include/linux/kconfig.h b/tools/include/linux/kconfig.h
new file mode 100644
index 000000000000..13b86bd3b746
--- /dev/null
+++ b/tools/include/linux/kconfig.h
@@ -0,0 +1,67 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _TOOLS_LINUX_KCONFIG_H
+#define _TOOLS_LINUX_KCONFIG_H
+
+/* CONFIG_CC_VERSION_TEXT (Do not delete this comment. See help in Kconfig) */
+
+#define __ARG_PLACEHOLDER_1 0,
+#define __take_second_arg(__ignored, val, ...) val
+
+/*
+ * The use of "&&" / "||" is limited in certain expressions.
+ * The following enable to calculate "and" / "or" with macro expansion only.
+ */
+#define __and(x, y) ___and(x, y)
+#define ___and(x, y) ____and(__ARG_PLACEHOLDER_##x, y)
+#define ____and(arg1_or_junk, y) __take_second_arg(arg1_or_junk y, 0)
+
+#define __or(x, y) ___or(x, y)
+#define ___or(x, y) ____or(__ARG_PLACEHOLDER_##x, y)
+#define ____or(arg1_or_junk, y) __take_second_arg(arg1_or_junk 1, y)
+
+/*
+ * Helper macros to use CONFIG_ options in C/CPP expressions. Note that
+ * these only work with boolean and tristate options.
+ */
+
+/*
+ * Getting something that works in C and CPP for an arg that may or may
+ * not be defined is tricky. Here, if we have "#define CONFIG_BOOGER 1"
+ * we match on the placeholder define, insert the "0," for arg1 and generate
+ * the triplet (0, 1, 0). Then the last step cherry picks the 2nd arg (a one).
+ * When CONFIG_BOOGER is not defined, we generate a (... 1, 0) pair, and when
+ * the last step cherry picks the 2nd arg, we get a zero.
+ */
+#define __is_defined(x) ___is_defined(x)
+#define ___is_defined(val) ____is_defined(__ARG_PLACEHOLDER_##val)
+#define ____is_defined(arg1_or_junk) __take_second_arg(arg1_or_junk 1, 0)
+
+/*
+ * IS_BUILTIN(CONFIG_FOO) evaluates to 1 if CONFIG_FOO is set to 'y', 0
+ * otherwise. For boolean options, this is equivalent to
+ * IS_ENABLED(CONFIG_FOO).
+ */
+#define IS_BUILTIN(option) __is_defined(option)
+
+/*
+ * IS_MODULE(CONFIG_FOO) evaluates to 1 if CONFIG_FOO is set to 'm', 0
+ * otherwise.
+ */
+#define IS_MODULE(option) __is_defined(option##_MODULE)
+
+/*
+ * IS_REACHABLE(CONFIG_FOO) evaluates to 1 if the currently compiled
+ * code can call a function defined in code compiled based on CONFIG_FOO.
+ * This is similar to IS_ENABLED(), but returns false when invoked from
+ * built-in code when CONFIG_FOO is set to 'm'.
+ */
+#define IS_REACHABLE(option) __or(IS_BUILTIN(option), \
+ __and(IS_MODULE(option), __is_defined(MODULE)))
+
+/*
+ * IS_ENABLED(CONFIG_FOO) evaluates to 1 if CONFIG_FOO is set to 'y' or 'm',
+ * 0 otherwise.
+ */
+#define IS_ENABLED(option) __or(IS_BUILTIN(option), IS_MODULE(option))
+
+#endif /* _TOOLS_LINUX_KCONFIG_H */
diff --git a/tools/include/linux/objtool.h b/tools/include/linux/objtool.h
index 577f51436cf9..662f19374bd9 100644
--- a/tools/include/linux/objtool.h
+++ b/tools/include/linux/objtool.h
@@ -29,11 +29,19 @@ struct unwind_hint {
*
* UNWIND_HINT_TYPE_REGS_PARTIAL: Used in entry code to indicate that
* sp_reg+sp_offset points to the iret return frame.
+ *
+ * UNWIND_HINT_FUNC: Generate the unwind metadata of a callable function.
+ * Useful for code which doesn't have an ELF function annotation.
+ *
+ * UNWIND_HINT_ENTRY: machine entry without stack, SYSCALL/SYSENTER etc.
*/
#define UNWIND_HINT_TYPE_CALL 0
#define UNWIND_HINT_TYPE_REGS 1
#define UNWIND_HINT_TYPE_REGS_PARTIAL 2
-#define UNWIND_HINT_TYPE_RET_OFFSET 3
+#define UNWIND_HINT_TYPE_FUNC 3
+#define UNWIND_HINT_TYPE_ENTRY 4
+#define UNWIND_HINT_TYPE_SAVE 5
+#define UNWIND_HINT_TYPE_RESTORE 6

#ifdef CONFIG_STACK_VALIDATION

@@ -96,7 +104,7 @@ struct unwind_hint {
* the debuginfo as necessary. It will also warn if it sees any
* inconsistencies.
*/
-.macro UNWIND_HINT sp_reg:req sp_offset=0 type:req end=0
+.macro UNWIND_HINT type:req sp_reg=0 sp_offset=0 end=0
.Lunwind_hint_ip_\@:
.pushsection .discard.unwind_hints
/* struct unwind_hint */
@@ -120,7 +128,7 @@ struct unwind_hint {
#define STACK_FRAME_NON_STANDARD(func)
#else
#define ANNOTATE_INTRA_FUNCTION_CALL
-.macro UNWIND_HINT sp_reg:req sp_offset=0 type:req end=0
+.macro UNWIND_HINT type:req sp_reg=0 sp_offset=0 end=0
.endm
#endif

diff --git a/tools/objtool/Documentation/stack-validation.txt b/tools/objtool/Documentation/stack-validation.txt
index 0542e46c7552..30f38fdc0d56 100644
--- a/tools/objtool/Documentation/stack-validation.txt
+++ b/tools/objtool/Documentation/stack-validation.txt
@@ -315,13 +315,15 @@ they mean, and suggestions for how to fix them.
function tracing inserts additional calls, which is not obvious from the
sources).

-10. file.o: warning: func()+0x5c: alternative modifies stack
-
- This means that an alternative includes instructions that modify the
- stack. The problem is that there is only one ORC unwind table, this means
- that the ORC unwind entries must be valid for each of the alternatives.
- The easiest way to enforce this is to ensure alternatives do not contain
- any ORC entries, which in turn implies the above constraint.
+10. file.o: warning: func()+0x5c: stack layout conflict in alternatives
+
+ This means that in the use of the alternative() or ALTERNATIVE()
+ macro, the code paths have conflicting modifications to the stack.
+ The problem is that there is only one ORC unwind table, which means
+ that the ORC unwind entries must be consistent for all possible
+ instruction boundaries regardless of which code has been patched.
+ This limitation can be overcome by massaging the alternatives with
+ NOPs to shift the stack changes around so they no longer conflict.

11. file.o: warning: unannotated intra-function call

diff --git a/tools/objtool/Makefile b/tools/objtool/Makefile
index 5cdb19036d7f..a43096f713c7 100644
--- a/tools/objtool/Makefile
+++ b/tools/objtool/Makefile
@@ -46,10 +46,6 @@ ifeq ($(SRCARCH),x86)
SUBCMD_ORC := y
endif

-ifeq ($(SUBCMD_ORC),y)
- CFLAGS += -DINSN_USE_ORC
-endif
-
export SUBCMD_CHECK SUBCMD_ORC
export srctree OUTPUT CFLAGS SRCARCH AWK
include $(srctree)/tools/build/Makefile.include
diff --git a/tools/objtool/arch.h b/tools/objtool/arch.h
index 4a84c3081b8e..580ce1857585 100644
--- a/tools/objtool/arch.h
+++ b/tools/objtool/arch.h
@@ -11,10 +11,6 @@
#include "objtool.h"
#include "cfi.h"

-#ifdef INSN_USE_ORC
-#include <asm/orc_types.h>
-#endif
-
enum insn_type {
INSN_JUMP_CONDITIONAL,
INSN_JUMP_UNCONDITIONAL,
@@ -30,6 +26,7 @@ enum insn_type {
INSN_CLAC,
INSN_STD,
INSN_CLD,
+ INSN_TRAP,
INSN_OTHER,
};

@@ -87,7 +84,13 @@ unsigned long arch_jump_destination(struct instruction *insn);
unsigned long arch_dest_reloc_offset(int addend);

const char *arch_nop_insn(int len);
+const char *arch_ret_insn(int len);
+
+int arch_decode_hint_reg(u8 sp_reg, int *base);
+
+bool arch_is_retpoline(struct symbol *sym);
+bool arch_is_rethunk(struct symbol *sym);

-int arch_decode_hint_reg(struct instruction *insn, u8 sp_reg);
+int arch_rewrite_retpolines(struct objtool_file *file);

#endif /* _ARCH_H */
diff --git a/tools/objtool/arch/x86/decode.c b/tools/objtool/arch/x86/decode.c
index cde9c36e40ae..d8f47704fd85 100644
--- a/tools/objtool/arch/x86/decode.c
+++ b/tools/objtool/arch/x86/decode.c
@@ -16,6 +16,7 @@
#include "../../arch.h"
#include "../../warn.h"
#include <asm/orc_types.h>
+#include "arch_elf.h"

static unsigned char op_to_cfi_reg[][2] = {
{CFI_AX, CFI_R8},
@@ -455,6 +456,11 @@ int arch_decode_instruction(const struct elf *elf, const struct section *sec,

break;

+ case 0xcc:
+ /* int3 */
+ *type = INSN_TRAP;
+ break;
+
case 0xe3:
/* jecxz/jrcxz */
*type = INSN_JUMP_CONDITIONAL;
@@ -563,8 +569,8 @@ void arch_initial_func_cfi_state(struct cfi_init_state *state)
state->cfa.offset = 8;

/* initial RA (return address) */
- state->regs[16].base = CFI_CFA;
- state->regs[16].offset = -8;
+ state->regs[CFI_RA].base = CFI_CFA;
+ state->regs[CFI_RA].offset = -8;
}

const char *arch_nop_insn(int len)
@@ -585,34 +591,52 @@ const char *arch_nop_insn(int len)
return nops[len-1];
}

-int arch_decode_hint_reg(struct instruction *insn, u8 sp_reg)
+#define BYTE_RET 0xC3
+
+const char *arch_ret_insn(int len)
{
- struct cfi_reg *cfa = &insn->cfi.cfa;
+ static const char ret[5][5] = {
+ { BYTE_RET },
+ { BYTE_RET, 0xcc },
+ { BYTE_RET, 0xcc, 0x90 },
+ { BYTE_RET, 0xcc, 0x66, 0x90 },
+ { BYTE_RET, 0xcc, 0x0f, 0x1f, 0x00 },
+ };

+ if (len < 1 || len > 5) {
+ WARN("invalid RET size: %d\n", len);
+ return NULL;
+ }
+
+ return ret[len-1];
+}
+
+int arch_decode_hint_reg(u8 sp_reg, int *base)
+{
switch (sp_reg) {
case ORC_REG_UNDEFINED:
- cfa->base = CFI_UNDEFINED;
+ *base = CFI_UNDEFINED;
break;
case ORC_REG_SP:
- cfa->base = CFI_SP;
+ *base = CFI_SP;
break;
case ORC_REG_BP:
- cfa->base = CFI_BP;
+ *base = CFI_BP;
break;
case ORC_REG_SP_INDIRECT:
- cfa->base = CFI_SP_INDIRECT;
+ *base = CFI_SP_INDIRECT;
break;
case ORC_REG_R10:
- cfa->base = CFI_R10;
+ *base = CFI_R10;
break;
case ORC_REG_R13:
- cfa->base = CFI_R13;
+ *base = CFI_R13;
break;
case ORC_REG_DI:
- cfa->base = CFI_DI;
+ *base = CFI_DI;
break;
case ORC_REG_DX:
- cfa->base = CFI_DX;
+ *base = CFI_DX;
break;
default:
return -1;
@@ -620,3 +644,13 @@ int arch_decode_hint_reg(struct instruction *insn, u8 sp_reg)

return 0;
}
+
+bool arch_is_retpoline(struct symbol *sym)
+{
+ return !strncmp(sym->name, "__x86_indirect_", 15);
+}
+
+bool arch_is_rethunk(struct symbol *sym)
+{
+ return !strcmp(sym->name, "__x86_return_thunk");
+}
diff --git a/tools/objtool/arch/x86/include/arch_special.h b/tools/objtool/arch/x86/include/arch_special.h
index d818b2bffa02..14271cca0c74 100644
--- a/tools/objtool/arch/x86/include/arch_special.h
+++ b/tools/objtool/arch/x86/include/arch_special.h
@@ -10,7 +10,7 @@
#define JUMP_ORIG_OFFSET 0
#define JUMP_NEW_OFFSET 4

-#define ALT_ENTRY_SIZE 13
+#define ALT_ENTRY_SIZE 12
#define ALT_ORIG_OFFSET 0
#define ALT_NEW_OFFSET 4
#define ALT_FEATURE_OFFSET 8
diff --git a/tools/objtool/builtin-check.c b/tools/objtool/builtin-check.c
index c6d199bfd0ae..447a49c03abb 100644
--- a/tools/objtool/builtin-check.c
+++ b/tools/objtool/builtin-check.c
@@ -18,7 +18,8 @@
#include "builtin.h"
#include "objtool.h"

-bool no_fp, no_unreachable, retpoline, module, backtrace, uaccess, stats, validate_dup, vmlinux;
+bool no_fp, no_unreachable, retpoline, module, backtrace, uaccess, stats,
+ validate_dup, vmlinux, sls, unret, rethunk;

static const char * const check_usage[] = {
"objtool check [<options>] file.o",
@@ -29,12 +30,15 @@ const struct option check_options[] = {
OPT_BOOLEAN('f', "no-fp", &no_fp, "Skip frame pointer validation"),
OPT_BOOLEAN('u', "no-unreachable", &no_unreachable, "Skip 'unreachable instruction' warnings"),
OPT_BOOLEAN('r', "retpoline", &retpoline, "Validate retpoline assumptions"),
+ OPT_BOOLEAN(0, "rethunk", &rethunk, "validate and annotate rethunk usage"),
+ OPT_BOOLEAN(0, "unret", &unret, "validate entry unret placement"),
OPT_BOOLEAN('m', "module", &module, "Indicates the object will be part of a kernel module"),
OPT_BOOLEAN('b', "backtrace", &backtrace, "unwind on error"),
OPT_BOOLEAN('a', "uaccess", &uaccess, "enable uaccess checking"),
OPT_BOOLEAN('s', "stats", &stats, "print statistics"),
OPT_BOOLEAN('d', "duplicate", &validate_dup, "duplicate validation for vmlinux.o"),
OPT_BOOLEAN('l', "vmlinux", &vmlinux, "vmlinux.o validation"),
+ OPT_BOOLEAN('S', "sls", &sls, "validate straight-line-speculation"),
OPT_END(),
};

diff --git a/tools/objtool/builtin-orc.c b/tools/objtool/builtin-orc.c
index 7b31121fa60b..508bdf6ae8dc 100644
--- a/tools/objtool/builtin-orc.c
+++ b/tools/objtool/builtin-orc.c
@@ -51,11 +51,7 @@ int cmd_orc(int argc, const char **argv)
if (list_empty(&file->insn_list))
return 0;

- ret = create_orc(file);
- if (ret)
- return ret;
-
- ret = create_orc_sections(file);
+ ret = orc_create(file);
if (ret)
return ret;

diff --git a/tools/objtool/builtin.h b/tools/objtool/builtin.h
index 85c979caa367..61d8d49dbc65 100644
--- a/tools/objtool/builtin.h
+++ b/tools/objtool/builtin.h
@@ -8,7 +8,8 @@
#include <subcmd/parse-options.h>

extern const struct option check_options[];
-extern bool no_fp, no_unreachable, retpoline, module, backtrace, uaccess, stats, validate_dup, vmlinux;
+extern bool no_fp, no_unreachable, retpoline, module, backtrace, uaccess, stats,
+ validate_dup, vmlinux, sls, unret, rethunk;

extern int cmd_check(int argc, const char **argv);
extern int cmd_orc(int argc, const char **argv);
diff --git a/tools/objtool/cfi.h b/tools/objtool/cfi.h
index c7c59c6a44ee..f579802d7ec2 100644
--- a/tools/objtool/cfi.h
+++ b/tools/objtool/cfi.h
@@ -7,6 +7,7 @@
#define _OBJTOOL_CFI_H

#include "cfi_regs.h"
+#include <linux/list.h>

#define CFI_UNDEFINED -1
#define CFI_CFA -2
@@ -24,6 +25,7 @@ struct cfi_init_state {
};

struct cfi_state {
+ struct hlist_node hash; /* must be first, cficmp() */
struct cfi_reg regs[CFI_NUM_REGS];
struct cfi_reg vals[CFI_NUM_REGS];
struct cfi_reg cfa;
diff --git a/tools/objtool/check.c b/tools/objtool/check.c
index 8932f41c387f..ea80b29b9913 100644
--- a/tools/objtool/check.c
+++ b/tools/objtool/check.c
@@ -5,6 +5,8 @@

#include <string.h>
#include <stdlib.h>
+#include <inttypes.h>
+#include <sys/mman.h>

#include "builtin.h"
#include "cfi.h"
@@ -19,15 +21,17 @@
#include <linux/kernel.h>
#include <linux/static_call_types.h>

-#define FAKE_JUMP_OFFSET -1
-
struct alternative {
struct list_head list;
struct instruction *insn;
bool skip_orig;
};

-struct cfi_init_state initial_func_cfi;
+static unsigned long nr_cfi, nr_cfi_reused, nr_cfi_cache;
+
+static struct cfi_init_state initial_func_cfi;
+static struct cfi_state init_cfi;
+static struct cfi_state func_cfi;

struct instruction *find_insn(struct objtool_file *file,
struct section *sec, unsigned long offset)
@@ -109,17 +113,34 @@ static struct instruction *prev_insn_same_sym(struct objtool_file *file,
for (insn = next_insn_same_sec(file, insn); insn; \
insn = next_insn_same_sec(file, insn))

+static bool is_jump_table_jump(struct instruction *insn)
+{
+ struct alt_group *alt_group = insn->alt_group;
+
+ if (insn->jump_table)
+ return true;
+
+ /* Retpoline alternative for a jump table? */
+ return alt_group && alt_group->orig_group &&
+ alt_group->orig_group->first_insn->jump_table;
+}
+
static bool is_sibling_call(struct instruction *insn)
{
+ /*
+ * Assume only ELF functions can make sibling calls. This ensures
+ * sibling call detection consistency between vmlinux.o and individual
+ * objects.
+ */
+ if (!insn->func)
+ return false;
+
/* An indirect jump is either a sibling call or a jump to a table. */
if (insn->type == INSN_JUMP_DYNAMIC)
- return list_empty(&insn->alts);
-
- if (!is_static_jump(insn))
- return false;
+ return !is_jump_table_jump(insn);

/* add_jump_destinations() sets insn->call_dest for sibling calls. */
- return !!insn->call_dest;
+ return (is_static_jump(insn) && insn->call_dest);
}

/*
@@ -250,6 +271,78 @@ static void init_insn_state(struct insn_state *state, struct section *sec)
state->noinstr = sec->noinstr;
}

+static struct cfi_state *cfi_alloc(void)
+{
+ struct cfi_state *cfi = calloc(sizeof(struct cfi_state), 1);
+ if (!cfi) {
+ WARN("calloc failed");
+ exit(1);
+ }
+ nr_cfi++;
+ return cfi;
+}
+
+static int cfi_bits;
+static struct hlist_head *cfi_hash;
+
+static inline bool cficmp(struct cfi_state *cfi1, struct cfi_state *cfi2)
+{
+ return memcmp((void *)cfi1 + sizeof(cfi1->hash),
+ (void *)cfi2 + sizeof(cfi2->hash),
+ sizeof(struct cfi_state) - sizeof(struct hlist_node));
+}
+
+static inline u32 cfi_key(struct cfi_state *cfi)
+{
+ return jhash((void *)cfi + sizeof(cfi->hash),
+ sizeof(*cfi) - sizeof(cfi->hash), 0);
+}
+
+static struct cfi_state *cfi_hash_find_or_add(struct cfi_state *cfi)
+{
+ struct hlist_head *head = &cfi_hash[hash_min(cfi_key(cfi), cfi_bits)];
+ struct cfi_state *obj;
+
+ hlist_for_each_entry(obj, head, hash) {
+ if (!cficmp(cfi, obj)) {
+ nr_cfi_cache++;
+ return obj;
+ }
+ }
+
+ obj = cfi_alloc();
+ *obj = *cfi;
+ hlist_add_head(&obj->hash, head);
+
+ return obj;
+}
+
+static void cfi_hash_add(struct cfi_state *cfi)
+{
+ struct hlist_head *head = &cfi_hash[hash_min(cfi_key(cfi), cfi_bits)];
+
+ hlist_add_head(&cfi->hash, head);
+}
+
+static void *cfi_hash_alloc(void)
+{
+ cfi_bits = vmlinux ? ELF_HASH_BITS - 3 : 13;
+ cfi_hash = mmap(NULL, sizeof(struct hlist_head) << cfi_bits,
+ PROT_READ|PROT_WRITE,
+ MAP_PRIVATE|MAP_ANON, -1, 0);
+ if (cfi_hash == (void *)-1L) {
+ WARN("mmap fail cfi_hash");
+ cfi_hash = NULL;
+ } else if (stats) {
+ printf("cfi_bits: %d\n", cfi_bits);
+ }
+
+ return cfi_hash;
+}
+
+static unsigned long nr_insns;
+static unsigned long nr_insns_visited;
+
/*
* Call the arch-specific instruction decoder for all the instructions and add
* them to the global instruction list.
@@ -260,7 +353,6 @@ static int decode_instructions(struct objtool_file *file)
struct symbol *func;
unsigned long offset;
struct instruction *insn;
- unsigned long nr_insns = 0;
int ret;

for_each_sec(file, sec) {
@@ -274,7 +366,8 @@ static int decode_instructions(struct objtool_file *file)
sec->text = true;

if (!strcmp(sec->name, ".noinstr.text") ||
- !strcmp(sec->name, ".entry.text"))
+ !strcmp(sec->name, ".entry.text") ||
+ !strncmp(sec->name, ".text.__x86.", 12))
sec->noinstr = true;

for (offset = 0; offset < sec->len; offset += insn->len) {
@@ -286,7 +379,6 @@ static int decode_instructions(struct objtool_file *file)
memset(insn, 0, sizeof(*insn));
INIT_LIST_HEAD(&insn->alts);
INIT_LIST_HEAD(&insn->stack_ops);
- init_cfi_state(&insn->cfi);

insn->sec = sec;
insn->offset = offset;
@@ -377,12 +469,12 @@ static int add_dead_ends(struct objtool_file *file)
else if (reloc->addend == reloc->sym->sec->len) {
insn = find_last_insn(file, reloc->sym->sec);
if (!insn) {
- WARN("can't find unreachable insn at %s+0x%x",
+ WARN("can't find unreachable insn at %s+0x%" PRIx64,
reloc->sym->sec->name, reloc->addend);
return -1;
}
} else {
- WARN("can't find unreachable insn at %s+0x%x",
+ WARN("can't find unreachable insn at %s+0x%" PRIx64,
reloc->sym->sec->name, reloc->addend);
return -1;
}
@@ -412,12 +504,12 @@ static int add_dead_ends(struct objtool_file *file)
else if (reloc->addend == reloc->sym->sec->len) {
insn = find_last_insn(file, reloc->sym->sec);
if (!insn) {
- WARN("can't find reachable insn at %s+0x%x",
+ WARN("can't find reachable insn at %s+0x%" PRIx64,
reloc->sym->sec->name, reloc->addend);
return -1;
}
} else {
- WARN("can't find reachable insn at %s+0x%x",
+ WARN("can't find reachable insn at %s+0x%" PRIx64,
reloc->sym->sec->name, reloc->addend);
return -1;
}
@@ -430,8 +522,7 @@ static int add_dead_ends(struct objtool_file *file)

static int create_static_call_sections(struct objtool_file *file)
{
- struct section *sec, *reloc_sec;
- struct reloc *reloc;
+ struct section *sec;
struct static_call_site *site;
struct instruction *insn;
struct symbol *key_sym;
@@ -449,7 +540,7 @@ static int create_static_call_sections(struct objtool_file *file)
return 0;

idx = 0;
- list_for_each_entry(insn, &file->static_call_list, static_call_node)
+ list_for_each_entry(insn, &file->static_call_list, call_node)
idx++;

sec = elf_create_section(file->elf, ".static_call_sites", SHF_WRITE,
@@ -457,36 +548,18 @@ static int create_static_call_sections(struct objtool_file *file)
if (!sec)
return -1;

- reloc_sec = elf_create_reloc_section(file->elf, sec, SHT_RELA);
- if (!reloc_sec)
- return -1;
-
idx = 0;
- list_for_each_entry(insn, &file->static_call_list, static_call_node) {
+ list_for_each_entry(insn, &file->static_call_list, call_node) {

site = (struct static_call_site *)sec->data->d_buf + idx;
memset(site, 0, sizeof(struct static_call_site));

/* populate reloc for 'addr' */
- reloc = malloc(sizeof(*reloc));
-
- if (!reloc) {
- perror("malloc");
- return -1;
- }
- memset(reloc, 0, sizeof(*reloc));
-
- insn_to_reloc_sym_addend(insn->sec, insn->offset, reloc);
- if (!reloc->sym) {
- WARN_FUNC("static call tramp: missing containing symbol",
- insn->sec, insn->offset);
+ if (elf_add_reloc_to_insn(file->elf, sec,
+ idx * sizeof(struct static_call_site),
+ R_X86_64_PC32,
+ insn->sec, insn->offset))
return -1;
- }
-
- reloc->type = R_X86_64_PC32;
- reloc->offset = idx * sizeof(struct static_call_site);
- reloc->sec = reloc_sec;
- elf_add_reloc(file->elf, reloc);

/* find key symbol */
key_name = strdup(insn->call_dest->name);
@@ -523,24 +596,106 @@ static int create_static_call_sections(struct objtool_file *file)
free(key_name);

/* populate reloc for 'key' */
- reloc = malloc(sizeof(*reloc));
- if (!reloc) {
- perror("malloc");
+ if (elf_add_reloc(file->elf, sec,
+ idx * sizeof(struct static_call_site) + 4,
+ R_X86_64_PC32, key_sym,
+ is_sibling_call(insn) * STATIC_CALL_SITE_TAIL))
+ return -1;
+
+ idx++;
+ }
+
+ return 0;
+}
+
+static int create_retpoline_sites_sections(struct objtool_file *file)
+{
+ struct instruction *insn;
+ struct section *sec;
+ int idx;
+
+ sec = find_section_by_name(file->elf, ".retpoline_sites");
+ if (sec) {
+ WARN("file already has .retpoline_sites, skipping");
+ return 0;
+ }
+
+ idx = 0;
+ list_for_each_entry(insn, &file->retpoline_call_list, call_node)
+ idx++;
+
+ if (!idx)
+ return 0;
+
+ sec = elf_create_section(file->elf, ".retpoline_sites", 0,
+ sizeof(int), idx);
+ if (!sec) {
+ WARN("elf_create_section: .retpoline_sites");
+ return -1;
+ }
+
+ idx = 0;
+ list_for_each_entry(insn, &file->retpoline_call_list, call_node) {
+
+ int *site = (int *)sec->data->d_buf + idx;
+ *site = 0;
+
+ if (elf_add_reloc_to_insn(file->elf, sec,
+ idx * sizeof(int),
+ R_X86_64_PC32,
+ insn->sec, insn->offset)) {
+ WARN("elf_add_reloc_to_insn: .retpoline_sites");
return -1;
}
- memset(reloc, 0, sizeof(*reloc));
- reloc->sym = key_sym;
- reloc->addend = is_sibling_call(insn) ? STATIC_CALL_SITE_TAIL : 0;
- reloc->type = R_X86_64_PC32;
- reloc->offset = idx * sizeof(struct static_call_site) + 4;
- reloc->sec = reloc_sec;
- elf_add_reloc(file->elf, reloc);

idx++;
}

- if (elf_rebuild_reloc_section(file->elf, reloc_sec))
+ return 0;
+}
+
+static int create_return_sites_sections(struct objtool_file *file)
+{
+ struct instruction *insn;
+ struct section *sec;
+ int idx;
+
+ sec = find_section_by_name(file->elf, ".return_sites");
+ if (sec) {
+ WARN("file already has .return_sites, skipping");
+ return 0;
+ }
+
+ idx = 0;
+ list_for_each_entry(insn, &file->return_thunk_list, call_node)
+ idx++;
+
+ if (!idx)
+ return 0;
+
+ sec = elf_create_section(file->elf, ".return_sites", 0,
+ sizeof(int), idx);
+ if (!sec) {
+ WARN("elf_create_section: .return_sites");
return -1;
+ }
+
+ idx = 0;
+ list_for_each_entry(insn, &file->return_thunk_list, call_node) {
+
+ int *site = (int *)sec->data->d_buf + idx;
+ *site = 0;
+
+ if (elf_add_reloc_to_insn(file->elf, sec,
+ idx * sizeof(int),
+ R_X86_64_PC32,
+ insn->sec, insn->offset)) {
+ WARN("elf_add_reloc_to_insn: .return_sites");
+ return -1;
+ }
+
+ idx++;
+ }

return 0;
}
@@ -775,6 +930,172 @@ static int add_ignore_alternatives(struct objtool_file *file)
return 0;
}

+__weak bool arch_is_retpoline(struct symbol *sym)
+{
+ return false;
+}
+
+__weak bool arch_is_rethunk(struct symbol *sym)
+{
+ return false;
+}
+
+#define NEGATIVE_RELOC ((void *)-1L)
+
+static struct reloc *insn_reloc(struct objtool_file *file, struct instruction *insn)
+{
+ if (insn->reloc == NEGATIVE_RELOC)
+ return NULL;
+
+ if (!insn->reloc) {
+ insn->reloc = find_reloc_by_dest_range(file->elf, insn->sec,
+ insn->offset, insn->len);
+ if (!insn->reloc) {
+ insn->reloc = NEGATIVE_RELOC;
+ return NULL;
+ }
+ }
+
+ return insn->reloc;
+}
+
+static void remove_insn_ops(struct instruction *insn)
+{
+ struct stack_op *op, *tmp;
+
+ list_for_each_entry_safe(op, tmp, &insn->stack_ops, list) {
+ list_del(&op->list);
+ free(op);
+ }
+}
+
+static void annotate_call_site(struct objtool_file *file,
+ struct instruction *insn, bool sibling)
+{
+ struct reloc *reloc = insn_reloc(file, insn);
+ struct symbol *sym = insn->call_dest;
+
+ if (!sym)
+ sym = reloc->sym;
+
+ /*
+ * Alternative replacement code is just template code which is
+ * sometimes copied to the original instruction. For now, don't
+ * annotate it. (In the future we might consider annotating the
+ * original instruction if/when it ever makes sense to do so.)
+ */
+ if (!strcmp(insn->sec->name, ".altinstr_replacement"))
+ return;
+
+ if (sym->static_call_tramp) {
+ list_add_tail(&insn->call_node, &file->static_call_list);
+ return;
+ }
+
+ if (sym->retpoline_thunk) {
+ list_add_tail(&insn->call_node, &file->retpoline_call_list);
+ return;
+ }
+
+ /*
+ * Many compilers cannot disable KCOV with a function attribute
+ * so they need a little help, NOP out any KCOV calls from noinstr
+ * text.
+ */
+ if (insn->sec->noinstr && sym->kcov) {
+ if (reloc) {
+ reloc->type = R_NONE;
+ elf_write_reloc(file->elf, reloc);
+ }
+
+ elf_write_insn(file->elf, insn->sec,
+ insn->offset, insn->len,
+ sibling ? arch_ret_insn(insn->len)
+ : arch_nop_insn(insn->len));
+
+ insn->type = sibling ? INSN_RETURN : INSN_NOP;
+
+ if (sibling) {
+ /*
+ * We've replaced the tail-call JMP insn by two new
+ * insn: RET; INT3, except we only have a single struct
+ * insn here. Mark it retpoline_safe to avoid the SLS
+ * warning, instead of adding another insn.
+ */
+ insn->retpoline_safe = true;
+ }
+
+ return;
+ }
+}
+
+static void add_call_dest(struct objtool_file *file, struct instruction *insn,
+ struct symbol *dest, bool sibling)
+{
+ insn->call_dest = dest;
+ if (!dest)
+ return;
+
+ /*
+ * Whatever stack impact regular CALLs have, should be undone
+ * by the RETURN of the called function.
+ *
+ * Annotated intra-function calls retain the stack_ops but
+ * are converted to JUMP, see read_intra_function_calls().
+ */
+ remove_insn_ops(insn);
+
+ annotate_call_site(file, insn, sibling);
+}
+
+static void add_retpoline_call(struct objtool_file *file, struct instruction *insn)
+{
+ /*
+ * Retpoline calls/jumps are really dynamic calls/jumps in disguise,
+ * so convert them accordingly.
+ */
+ switch (insn->type) {
+ case INSN_CALL:
+ insn->type = INSN_CALL_DYNAMIC;
+ break;
+ case INSN_JUMP_UNCONDITIONAL:
+ insn->type = INSN_JUMP_DYNAMIC;
+ break;
+ case INSN_JUMP_CONDITIONAL:
+ insn->type = INSN_JUMP_DYNAMIC_CONDITIONAL;
+ break;
+ default:
+ return;
+ }
+
+ insn->retpoline_safe = true;
+
+ /*
+ * Whatever stack impact regular CALLs have, should be undone
+ * by the RETURN of the called function.
+ *
+ * Annotated intra-function calls retain the stack_ops but
+ * are converted to JUMP, see read_intra_function_calls().
+ */
+ remove_insn_ops(insn);
+
+ annotate_call_site(file, insn, false);
+}
+
+static void add_return_call(struct objtool_file *file, struct instruction *insn, bool add)
+{
+ /*
+ * Return thunk tail calls are really just returns in disguise,
+ * so convert them accordingly.
+ */
+ insn->type = INSN_RETURN;
+ insn->retpoline_safe = true;
+
+ /* Skip the non-text sections, specially .discard ones */
+ if (add && insn->sec->text)
+ list_add_tail(&insn->call_node, &file->return_thunk_list);
+}
+
/*
* Find the destination instructions for all jumps.
*/
@@ -789,46 +1110,35 @@ static int add_jump_destinations(struct objtool_file *file)
if (!is_static_jump(insn))
continue;

- if (insn->offset == FAKE_JUMP_OFFSET)
- continue;
-
- reloc = find_reloc_by_dest_range(file->elf, insn->sec,
- insn->offset, insn->len);
+ reloc = insn_reloc(file, insn);
if (!reloc) {
dest_sec = insn->sec;
dest_off = arch_jump_destination(insn);
} else if (reloc->sym->type == STT_SECTION) {
dest_sec = reloc->sym->sec;
dest_off = arch_dest_reloc_offset(reloc->addend);
+ } else if (reloc->sym->retpoline_thunk) {
+ add_retpoline_call(file, insn);
+ continue;
+ } else if (reloc->sym->return_thunk) {
+ add_return_call(file, insn, true);
+ continue;
+ } else if (insn->func) {
+ /* internal or external sibling call (with reloc) */
+ add_call_dest(file, insn, reloc->sym, true);
+ continue;
} else if (reloc->sym->sec->idx) {
dest_sec = reloc->sym->sec;
dest_off = reloc->sym->sym.st_value +
arch_dest_reloc_offset(reloc->addend);
- } else if (!strncmp(reloc->sym->name, "__x86_indirect_thunk_", 21) ||
- !strncmp(reloc->sym->name, "__x86_retpoline_", 16)) {
- /*
- * Retpoline jumps are really dynamic jumps in
- * disguise, so convert them accordingly.
- */
- if (insn->type == INSN_JUMP_UNCONDITIONAL)
- insn->type = INSN_JUMP_DYNAMIC;
- else
- insn->type = INSN_JUMP_DYNAMIC_CONDITIONAL;
-
- insn->retpoline_safe = true;
- continue;
} else {
- /* external sibling call */
- insn->call_dest = reloc->sym;
- if (insn->call_dest->static_call_tramp) {
- list_add_tail(&insn->static_call_node,
- &file->static_call_list);
- }
+ /* non-func asm code jumping to another file */
continue;
}

insn->jump_dest = find_insn(file, dest_sec, dest_off);
if (!insn->jump_dest) {
+ struct symbol *sym = find_symbol_by_offset(dest_sec, dest_off);

/*
* This is a special case where an alt instruction
@@ -838,6 +1148,19 @@ static int add_jump_destinations(struct objtool_file *file)
if (!strcmp(insn->sec->name, ".altinstr_replacement"))
continue;

+ /*
+ * This is a special case for zen_untrain_ret().
+ * It jumps to __x86_return_thunk(), but objtool
+ * can't find the thunk's starting RET
+ * instruction, because the RET is also in the
+ * middle of another instruction. Objtool only
+ * knows about the outer instruction.
+ */
+ if (sym && sym->return_thunk) {
+ add_return_call(file, insn, false);
+ continue;
+ }
+
WARN_FUNC("can't find jump dest instruction at %s+0x%lx",
insn->sec, insn->offset, dest_sec->name,
dest_off);
@@ -872,13 +1195,8 @@ static int add_jump_destinations(struct objtool_file *file)

} else if (insn->jump_dest->func->pfunc != insn->func->pfunc &&
insn->jump_dest->offset == insn->jump_dest->func->offset) {
-
- /* internal sibling call */
- insn->call_dest = insn->jump_dest->func;
- if (insn->call_dest->static_call_tramp) {
- list_add_tail(&insn->static_call_node,
- &file->static_call_list);
- }
+ /* internal sibling call (without reloc) */
+ add_call_dest(file, insn, insn->jump_dest->func, true);
}
}
}
@@ -886,16 +1204,6 @@ static int add_jump_destinations(struct objtool_file *file)
return 0;
}

-static void remove_insn_ops(struct instruction *insn)
-{
- struct stack_op *op, *tmp;
-
- list_for_each_entry_safe(op, tmp, &insn->stack_ops, list) {
- list_del(&op->list);
- free(op);
- }
-}
-
static struct symbol *find_call_destination(struct section *sec, unsigned long offset)
{
struct symbol *call_dest;
@@ -914,17 +1222,19 @@ static int add_call_destinations(struct objtool_file *file)
{
struct instruction *insn;
unsigned long dest_off;
+ struct symbol *dest;
struct reloc *reloc;

for_each_insn(file, insn) {
if (insn->type != INSN_CALL)
continue;

- reloc = find_reloc_by_dest_range(file->elf, insn->sec,
- insn->offset, insn->len);
+ reloc = insn_reloc(file, insn);
if (!reloc) {
dest_off = arch_jump_destination(insn);
- insn->call_dest = find_call_destination(insn->sec, dest_off);
+ dest = find_call_destination(insn->sec, dest_off);
+
+ add_call_dest(file, insn, dest, false);

if (insn->ignore)
continue;
@@ -942,122 +1252,104 @@ static int add_call_destinations(struct objtool_file *file)

} else if (reloc->sym->type == STT_SECTION) {
dest_off = arch_dest_reloc_offset(reloc->addend);
- insn->call_dest = find_call_destination(reloc->sym->sec,
- dest_off);
- if (!insn->call_dest) {
+ dest = find_call_destination(reloc->sym->sec, dest_off);
+ if (!dest) {
WARN_FUNC("can't find call dest symbol at %s+0x%lx",
insn->sec, insn->offset,
reloc->sym->sec->name,
dest_off);
return -1;
}
- } else
- insn->call_dest = reloc->sym;
-
- if (insn->call_dest && insn->call_dest->static_call_tramp) {
- list_add_tail(&insn->static_call_node,
- &file->static_call_list);
- }

- /*
- * Many compilers cannot disable KCOV with a function attribute
- * so they need a little help, NOP out any KCOV calls from noinstr
- * text.
- */
- if (insn->sec->noinstr &&
- !strncmp(insn->call_dest->name, "__sanitizer_cov_", 16)) {
- if (reloc) {
- reloc->type = R_NONE;
- elf_write_reloc(file->elf, reloc);
- }
+ add_call_dest(file, insn, dest, false);

- elf_write_insn(file->elf, insn->sec,
- insn->offset, insn->len,
- arch_nop_insn(insn->len));
- insn->type = INSN_NOP;
- }
+ } else if (reloc->sym->retpoline_thunk) {
+ add_retpoline_call(file, insn);

- /*
- * Whatever stack impact regular CALLs have, should be undone
- * by the RETURN of the called function.
- *
- * Annotated intra-function calls retain the stack_ops but
- * are converted to JUMP, see read_intra_function_calls().
- */
- remove_insn_ops(insn);
+ } else
+ add_call_dest(file, insn, reloc->sym, false);
}

return 0;
}

/*
- * The .alternatives section requires some extra special care, over and above
- * what other special sections require:
- *
- * 1. Because alternatives are patched in-place, we need to insert a fake jump
- * instruction at the end so that validate_branch() skips all the original
- * replaced instructions when validating the new instruction path.
- *
- * 2. An added wrinkle is that the new instruction length might be zero. In
- * that case the old instructions are replaced with noops. We simulate that
- * by creating a fake jump as the only new instruction.
- *
- * 3. In some cases, the alternative section includes an instruction which
- * conditionally jumps to the _end_ of the entry. We have to modify these
- * jumps' destinations to point back to .text rather than the end of the
- * entry in .altinstr_replacement.
+ * The .alternatives section requires some extra special care over and above
+ * other special sections because alternatives are patched in place.
*/
static int handle_group_alt(struct objtool_file *file,
struct special_alt *special_alt,
struct instruction *orig_insn,
struct instruction **new_insn)
{
- static unsigned int alt_group_next_index = 1;
- struct instruction *last_orig_insn, *last_new_insn, *insn, *fake_jump = NULL;
- unsigned int alt_group = alt_group_next_index++;
+ struct instruction *last_orig_insn, *last_new_insn = NULL, *insn, *nop = NULL;
+ struct alt_group *orig_alt_group, *new_alt_group;
unsigned long dest_off;

+
+ orig_alt_group = malloc(sizeof(*orig_alt_group));
+ if (!orig_alt_group) {
+ WARN("malloc failed");
+ return -1;
+ }
+ orig_alt_group->cfi = calloc(special_alt->orig_len,
+ sizeof(struct cfi_state *));
+ if (!orig_alt_group->cfi) {
+ WARN("calloc failed");
+ return -1;
+ }
+
last_orig_insn = NULL;
insn = orig_insn;
sec_for_each_insn_from(file, insn) {
if (insn->offset >= special_alt->orig_off + special_alt->orig_len)
break;

- insn->alt_group = alt_group;
+ insn->alt_group = orig_alt_group;
last_orig_insn = insn;
}
+ orig_alt_group->orig_group = NULL;
+ orig_alt_group->first_insn = orig_insn;
+ orig_alt_group->last_insn = last_orig_insn;

- if (next_insn_same_sec(file, last_orig_insn)) {
- fake_jump = malloc(sizeof(*fake_jump));
- if (!fake_jump) {
+
+ new_alt_group = malloc(sizeof(*new_alt_group));
+ if (!new_alt_group) {
+ WARN("malloc failed");
+ return -1;
+ }
+
+ if (special_alt->new_len < special_alt->orig_len) {
+ /*
+ * Insert a fake nop at the end to make the replacement
+ * alt_group the same size as the original. This is needed to
+ * allow propagate_alt_cfi() to do its magic. When the last
+ * instruction affects the stack, the instruction after it (the
+ * nop) will propagate the new state to the shared CFI array.
+ */
+ nop = malloc(sizeof(*nop));
+ if (!nop) {
WARN("malloc failed");
return -1;
}
- memset(fake_jump, 0, sizeof(*fake_jump));
- INIT_LIST_HEAD(&fake_jump->alts);
- INIT_LIST_HEAD(&fake_jump->stack_ops);
- init_cfi_state(&fake_jump->cfi);
+ memset(nop, 0, sizeof(*nop));
+ INIT_LIST_HEAD(&nop->alts);
+ INIT_LIST_HEAD(&nop->stack_ops);

- fake_jump->sec = special_alt->new_sec;
- fake_jump->offset = FAKE_JUMP_OFFSET;
- fake_jump->type = INSN_JUMP_UNCONDITIONAL;
- fake_jump->jump_dest = list_next_entry(last_orig_insn, list);
- fake_jump->func = orig_insn->func;
+ nop->sec = special_alt->new_sec;
+ nop->offset = special_alt->new_off + special_alt->new_len;
+ nop->len = special_alt->orig_len - special_alt->new_len;
+ nop->type = INSN_NOP;
+ nop->func = orig_insn->func;
+ nop->alt_group = new_alt_group;
+ nop->ignore = orig_insn->ignore_alts;
}

if (!special_alt->new_len) {
- if (!fake_jump) {
- WARN("%s: empty alternative at end of section",
- special_alt->orig_sec->name);
- return -1;
- }
-
- *new_insn = fake_jump;
- return 0;
+ *new_insn = nop;
+ goto end;
}

- last_new_insn = NULL;
- alt_group = alt_group_next_index++;
insn = *new_insn;
sec_for_each_insn_from(file, insn) {
struct reloc *alt_reloc;
@@ -1069,7 +1361,7 @@ static int handle_group_alt(struct objtool_file *file,

insn->ignore = orig_insn->ignore_alts;
insn->func = orig_insn->func;
- insn->alt_group = alt_group;
+ insn->alt_group = new_alt_group;

/*
* Since alternative replacement code is copy/pasted by the
@@ -1079,8 +1371,7 @@ static int handle_group_alt(struct objtool_file *file,
* alternatives code can adjust the relative offsets
* accordingly.
*/
- alt_reloc = find_reloc_by_dest_range(file->elf, insn->sec,
- insn->offset, insn->len);
+ alt_reloc = insn_reloc(file, insn);
if (alt_reloc &&
!arch_support_alt_relocation(special_alt, insn, alt_reloc)) {

@@ -1096,14 +1387,8 @@ static int handle_group_alt(struct objtool_file *file,
continue;

dest_off = arch_jump_destination(insn);
- if (dest_off == special_alt->new_off + special_alt->new_len) {
- if (!fake_jump) {
- WARN("%s: alternative jump to end of section",
- special_alt->orig_sec->name);
- return -1;
- }
- insn->jump_dest = fake_jump;
- }
+ if (dest_off == special_alt->new_off + special_alt->new_len)
+ insn->jump_dest = next_insn_same_sec(file, last_orig_insn);

if (!insn->jump_dest) {
WARN_FUNC("can't find alternative jump destination",
@@ -1118,9 +1403,13 @@ static int handle_group_alt(struct objtool_file *file,
return -1;
}

- if (fake_jump)
- list_add(&fake_jump->list, &last_new_insn->list);
-
+ if (nop)
+ list_add(&nop->list, &last_new_insn->list);
+end:
+ new_alt_group->orig_group = orig_alt_group;
+ new_alt_group->first_insn = *new_insn;
+ new_alt_group->last_insn = nop ? : last_new_insn;
+ new_alt_group->cfi = orig_alt_group->cfi;
return 0;
}

@@ -1412,13 +1701,21 @@ static int add_jump_table_alts(struct objtool_file *file)
return 0;
}

+static void set_func_state(struct cfi_state *state)
+{
+ state->cfa = initial_func_cfi.cfa;
+ memcpy(&state->regs, &initial_func_cfi.regs,
+ CFI_NUM_REGS * sizeof(struct cfi_reg));
+ state->stack_size = initial_func_cfi.cfa.offset;
+}
+
static int read_unwind_hints(struct objtool_file *file)
{
+ struct cfi_state cfi = init_cfi;
struct section *sec, *relocsec;
- struct reloc *reloc;
struct unwind_hint *hint;
struct instruction *insn;
- struct cfi_reg *cfa;
+ struct reloc *reloc;
int i;

sec = find_section_by_name(file->elf, ".discard.unwind_hints");
@@ -1453,24 +1750,51 @@ static int read_unwind_hints(struct objtool_file *file)
return -1;
}

- cfa = &insn->cfi.cfa;
+ insn->hint = true;
+
+ if (hint->type == UNWIND_HINT_TYPE_SAVE) {
+ insn->hint = false;
+ insn->save = true;
+ continue;
+ }
+
+ if (hint->type == UNWIND_HINT_TYPE_RESTORE) {
+ insn->restore = true;
+ continue;
+ }

- if (hint->type == UNWIND_HINT_TYPE_RET_OFFSET) {
- insn->ret_offset = hint->sp_offset;
+ if (hint->type == UNWIND_HINT_TYPE_REGS_PARTIAL) {
+ struct symbol *sym = find_symbol_by_offset(insn->sec, insn->offset);
+
+ if (sym && sym->bind == STB_GLOBAL) {
+ insn->entry = 1;
+ }
+ }
+
+ if (hint->type == UNWIND_HINT_TYPE_ENTRY) {
+ hint->type = UNWIND_HINT_TYPE_CALL;
+ insn->entry = 1;
+ }
+
+ if (hint->type == UNWIND_HINT_TYPE_FUNC) {
+ insn->cfi = &func_cfi;
continue;
}

- insn->hint = true;
+ if (insn->cfi)
+ cfi = *(insn->cfi);

- if (arch_decode_hint_reg(insn, hint->sp_reg)) {
+ if (arch_decode_hint_reg(hint->sp_reg, &cfi.cfa.base)) {
WARN_FUNC("unsupported unwind_hint sp base reg %d",
insn->sec, insn->offset, hint->sp_reg);
return -1;
}

- cfa->offset = hint->sp_offset;
- insn->cfi.type = hint->type;
- insn->cfi.end = hint->end;
+ cfi.cfa.offset = hint->sp_offset;
+ cfi.type = hint->type;
+ cfi.end = hint->end;
+
+ insn->cfi = cfi_hash_find_or_add(&cfi);
}

return 0;
@@ -1499,8 +1823,10 @@ static int read_retpoline_hints(struct objtool_file *file)
}

if (insn->type != INSN_JUMP_DYNAMIC &&
- insn->type != INSN_CALL_DYNAMIC) {
- WARN_FUNC("retpoline_safe hint not an indirect jump/call",
+ insn->type != INSN_CALL_DYNAMIC &&
+ insn->type != INSN_RETURN &&
+ insn->type != INSN_NOP) {
+ WARN_FUNC("retpoline_safe hint not an indirect jump/call/ret/nop",
insn->sec, insn->offset);
return -1;
}
@@ -1609,17 +1935,31 @@ static int read_intra_function_calls(struct objtool_file *file)
return 0;
}

-static int read_static_call_tramps(struct objtool_file *file)
+static int classify_symbols(struct objtool_file *file)
{
struct section *sec;
struct symbol *func;

for_each_sec(file, sec) {
list_for_each_entry(func, &sec->symbol_list, list) {
- if (func->bind == STB_GLOBAL &&
- !strncmp(func->name, STATIC_CALL_TRAMP_PREFIX_STR,
+ if (func->bind != STB_GLOBAL)
+ continue;
+
+ if (!strncmp(func->name, STATIC_CALL_TRAMP_PREFIX_STR,
strlen(STATIC_CALL_TRAMP_PREFIX_STR)))
func->static_call_tramp = true;
+
+ if (arch_is_retpoline(func))
+ func->retpoline_thunk = true;
+
+ if (arch_is_rethunk(func))
+ func->return_thunk = true;
+
+ if (!strcmp(func->name, "__fentry__"))
+ func->fentry = true;
+
+ if (!strncmp(func->name, "__sanitizer_cov_", 16))
+ func->kcov = true;
}
}

@@ -1676,10 +2016,14 @@ static int decode_sections(struct objtool_file *file)
/*
* Must be before add_{jump_call}_destination.
*/
- ret = read_static_call_tramps(file);
+ ret = classify_symbols(file);
if (ret)
return ret;

+ /*
+ * Must be before add_special_section_alts() as that depends on
+ * jump_dest being set.
+ */
ret = add_jump_destinations(file);
if (ret)
return ret;
@@ -1721,9 +2065,9 @@ static int decode_sections(struct objtool_file *file)

static bool is_fentry_call(struct instruction *insn)
{
- if (insn->type == INSN_CALL && insn->call_dest &&
- insn->call_dest->type == STT_NOTYPE &&
- !strcmp(insn->call_dest->name, "__fentry__"))
+ if (insn->type == INSN_CALL &&
+ insn->call_dest &&
+ insn->call_dest->fentry)
return true;

return false;
@@ -1731,27 +2075,18 @@ static bool is_fentry_call(struct instruction *insn)

static bool has_modified_stack_frame(struct instruction *insn, struct insn_state *state)
{
- u8 ret_offset = insn->ret_offset;
struct cfi_state *cfi = &state->cfi;
int i;

if (cfi->cfa.base != initial_func_cfi.cfa.base || cfi->drap)
return true;

- if (cfi->cfa.offset != initial_func_cfi.cfa.offset + ret_offset)
+ if (cfi->cfa.offset != initial_func_cfi.cfa.offset)
return true;

- if (cfi->stack_size != initial_func_cfi.cfa.offset + ret_offset)
+ if (cfi->stack_size != initial_func_cfi.cfa.offset)
return true;

- /*
- * If there is a ret offset hint then don't check registers
- * because a callee-saved register might have been pushed on
- * the stack.
- */
- if (ret_offset)
- return false;
-
for (i = 0; i < CFI_NUM_REGS; i++) {
if (cfi->regs[i].base != initial_func_cfi.regs[i].base ||
cfi->regs[i].offset != initial_func_cfi.regs[i].offset)
@@ -2220,22 +2555,52 @@ static int update_cfi_state(struct instruction *insn, struct cfi_state *cfi,
return 0;
}

-static int handle_insn_ops(struct instruction *insn, struct insn_state *state)
+/*
+ * The stack layouts of alternatives instructions can sometimes diverge when
+ * they have stack modifications. That's fine as long as the potential stack
+ * layouts don't conflict at any given potential instruction boundary.
+ *
+ * Flatten the CFIs of the different alternative code streams (both original
+ * and replacement) into a single shared CFI array which can be used to detect
+ * conflicts and nicely feed a linear array of ORC entries to the unwinder.
+ */
+static int propagate_alt_cfi(struct objtool_file *file, struct instruction *insn)
{
- struct stack_op *op;
+ struct cfi_state **alt_cfi;
+ int group_off;

- list_for_each_entry(op, &insn->stack_ops, list) {
- struct cfi_state old_cfi = state->cfi;
- int res;
+ if (!insn->alt_group)
+ return 0;
+
+ if (!insn->cfi) {
+ WARN("CFI missing");
+ return -1;
+ }

- res = update_cfi_state(insn, &state->cfi, op);
- if (res)
- return res;
+ alt_cfi = insn->alt_group->cfi;
+ group_off = insn->offset - insn->alt_group->first_insn->offset;

- if (insn->alt_group && memcmp(&state->cfi, &old_cfi, sizeof(struct cfi_state))) {
- WARN_FUNC("alternative modifies stack", insn->sec, insn->offset);
+ if (!alt_cfi[group_off]) {
+ alt_cfi[group_off] = insn->cfi;
+ } else {
+ if (cficmp(alt_cfi[group_off], insn->cfi)) {
+ WARN_FUNC("stack layout conflict in alternatives",
+ insn->sec, insn->offset);
return -1;
}
+ }
+
+ return 0;
+}
+
+static int handle_insn_ops(struct instruction *insn, struct insn_state *state)
+{
+ struct stack_op *op;
+
+ list_for_each_entry(op, &insn->stack_ops, list) {
+
+ if (update_cfi_state(insn, &state->cfi, op))
+ return 1;

if (op->dest.type == OP_DEST_PUSHF) {
if (!state->uaccess_stack) {
@@ -2264,9 +2629,14 @@ static int handle_insn_ops(struct instruction *insn, struct insn_state *state)

static bool insn_cfi_match(struct instruction *insn, struct cfi_state *cfi2)
{
- struct cfi_state *cfi1 = &insn->cfi;
+ struct cfi_state *cfi1 = insn->cfi;
int i;

+ if (!cfi1) {
+ WARN("CFI missing");
+ return false;
+ }
+
if (memcmp(&cfi1->cfa, &cfi2->cfa, sizeof(cfi1->cfa))) {

WARN_FUNC("stack state mismatch: cfa1=%d%+d cfa2=%d%+d",
@@ -2425,28 +2795,20 @@ static int validate_return(struct symbol *func, struct instruction *insn, struct
return 0;
}

-/*
- * Alternatives should not contain any ORC entries, this in turn means they
- * should not contain any CFI ops, which implies all instructions should have
- * the same same CFI state.
- *
- * It is possible to constuct alternatives that have unreachable holes that go
- * unreported (because they're NOPs), such holes would result in CFI_UNDEFINED
- * states which then results in ORC entries, which we just said we didn't want.
- *
- * Avoid them by copying the CFI entry of the first instruction into the whole
- * alternative.
- */
-static void fill_alternative_cfi(struct objtool_file *file, struct instruction *insn)
+static struct instruction *next_insn_to_validate(struct objtool_file *file,
+ struct instruction *insn)
{
- struct instruction *first_insn = insn;
- int alt_group = insn->alt_group;
+ struct alt_group *alt_group = insn->alt_group;

- sec_for_each_insn_continue(file, insn) {
- if (insn->alt_group != alt_group)
- break;
- insn->cfi = first_insn->cfi;
- }
+ /*
+ * Simulate the fact that alternatives are patched in-place. When the
+ * end of a replacement alt_group is reached, redirect objtool flow to
+ * the end of the original alt_group.
+ */
+ if (alt_group && insn == alt_group->last_insn && alt_group->orig_group)
+ return next_insn_same_sec(file, alt_group->orig_group->last_insn);
+
+ return next_insn_same_sec(file, insn);
}

/*
@@ -2459,7 +2821,7 @@ static int validate_branch(struct objtool_file *file, struct symbol *func,
struct instruction *insn, struct insn_state state)
{
struct alternative *alt;
- struct instruction *next_insn;
+ struct instruction *next_insn, *prev_insn = NULL;
struct section *sec;
u8 visited;
int ret;
@@ -2467,7 +2829,7 @@ static int validate_branch(struct objtool_file *file, struct symbol *func,
sec = insn->sec;

while (1) {
- next_insn = next_insn_same_sec(file, insn);
+ next_insn = next_insn_to_validate(file, insn);

if (file->c_file && func && insn->func && func != insn->func->pfunc) {
WARN("%s() falls through to next function %s()",
@@ -2481,25 +2843,67 @@ static int validate_branch(struct objtool_file *file, struct symbol *func,
return 1;
}

- visited = 1 << state.uaccess;
- if (insn->visited) {
+ visited = VISITED_BRANCH << state.uaccess;
+ if (insn->visited & VISITED_BRANCH_MASK) {
if (!insn->hint && !insn_cfi_match(insn, &state.cfi))
return 1;

if (insn->visited & visited)
return 0;
+ } else {
+ nr_insns_visited++;
}

if (state.noinstr)
state.instr += insn->instr;

- if (insn->hint)
- state.cfi = insn->cfi;
- else
- insn->cfi = state.cfi;
+ if (insn->hint) {
+ if (insn->restore) {
+ struct instruction *save_insn, *i;
+
+ i = insn;
+ save_insn = NULL;
+
+ sym_for_each_insn_continue_reverse(file, func, i) {
+ if (i->save) {
+ save_insn = i;
+ break;
+ }
+ }
+
+ if (!save_insn) {
+ WARN_FUNC("no corresponding CFI save for CFI restore",
+ sec, insn->offset);
+ return 1;
+ }
+
+ if (!save_insn->visited) {
+ WARN_FUNC("objtool isn't smart enough to handle this CFI save/restore combo",
+ sec, insn->offset);
+ return 1;
+ }
+
+ insn->cfi = save_insn->cfi;
+ nr_cfi_reused++;
+ }
+
+ state.cfi = *insn->cfi;
+ } else {
+ /* XXX track if we actually changed state.cfi */
+
+ if (prev_insn && !cficmp(prev_insn->cfi, &state.cfi)) {
+ insn->cfi = prev_insn->cfi;
+ nr_cfi_reused++;
+ } else {
+ insn->cfi = cfi_hash_find_or_add(&state.cfi);
+ }
+ }

insn->visited |= visited;

+ if (propagate_alt_cfi(file, insn))
+ return 1;
+
if (!insn->ignore_alts && !list_empty(&insn->alts)) {
bool skip_orig = false;

@@ -2515,9 +2919,6 @@ static int validate_branch(struct objtool_file *file, struct symbol *func,
}
}

- if (insn->alt_group)
- fill_alternative_cfi(file, insn);
-
if (skip_orig)
return 0;
}
@@ -2528,6 +2929,11 @@ static int validate_branch(struct objtool_file *file, struct symbol *func,
switch (insn->type) {

case INSN_RETURN:
+ if (sls && !insn->retpoline_safe &&
+ next_insn && next_insn->type != INSN_TRAP) {
+ WARN_FUNC("missing int3 after ret",
+ insn->sec, insn->offset);
+ }
return validate_return(func, insn, &state);

case INSN_CALL:
@@ -2550,7 +2956,7 @@ static int validate_branch(struct objtool_file *file, struct symbol *func,

case INSN_JUMP_CONDITIONAL:
case INSN_JUMP_UNCONDITIONAL:
- if (func && is_sibling_call(insn)) {
+ if (is_sibling_call(insn)) {
ret = validate_sibling_call(insn, &state);
if (ret)
return ret;
@@ -2571,8 +2977,15 @@ static int validate_branch(struct objtool_file *file, struct symbol *func,
break;

case INSN_JUMP_DYNAMIC:
+ if (sls && !insn->retpoline_safe &&
+ next_insn && next_insn->type != INSN_TRAP) {
+ WARN_FUNC("missing int3 after indirect jump",
+ insn->sec, insn->offset);
+ }
+
+ /* fallthrough */
case INSN_JUMP_DYNAMIC_CONDITIONAL:
- if (func && is_sibling_call(insn)) {
+ if (is_sibling_call(insn)) {
ret = validate_sibling_call(insn, &state);
if (ret)
return ret;
@@ -2646,6 +3059,7 @@ static int validate_branch(struct objtool_file *file, struct symbol *func,
return 1;
}

+ prev_insn = insn;
insn = next_insn;
}

@@ -2685,6 +3099,145 @@ static int validate_unwind_hints(struct objtool_file *file, struct section *sec)
return warnings;
}

+/*
+ * Validate rethunk entry constraint: must untrain RET before the first RET.
+ *
+ * Follow every branch (intra-function) and ensure ANNOTATE_UNRET_END comes
+ * before an actual RET instruction.
+ */
+static int validate_entry(struct objtool_file *file, struct instruction *insn)
+{
+ struct instruction *next, *dest;
+ int ret, warnings = 0;
+
+ for (;;) {
+ next = next_insn_to_validate(file, insn);
+
+ if (insn->visited & VISITED_ENTRY)
+ return 0;
+
+ insn->visited |= VISITED_ENTRY;
+
+ if (!insn->ignore_alts && !list_empty(&insn->alts)) {
+ struct alternative *alt;
+ bool skip_orig = false;
+
+ list_for_each_entry(alt, &insn->alts, list) {
+ if (alt->skip_orig)
+ skip_orig = true;
+
+ ret = validate_entry(file, alt->insn);
+ if (ret) {
+ if (backtrace)
+ BT_FUNC("(alt)", insn);
+ return ret;
+ }
+ }
+
+ if (skip_orig)
+ return 0;
+ }
+
+ switch (insn->type) {
+
+ case INSN_CALL_DYNAMIC:
+ case INSN_JUMP_DYNAMIC:
+ case INSN_JUMP_DYNAMIC_CONDITIONAL:
+ WARN_FUNC("early indirect call", insn->sec, insn->offset);
+ return 1;
+
+ case INSN_JUMP_UNCONDITIONAL:
+ case INSN_JUMP_CONDITIONAL:
+ if (!is_sibling_call(insn)) {
+ if (!insn->jump_dest) {
+ WARN_FUNC("unresolved jump target after linking?!?",
+ insn->sec, insn->offset);
+ return -1;
+ }
+ ret = validate_entry(file, insn->jump_dest);
+ if (ret) {
+ if (backtrace) {
+ BT_FUNC("(branch%s)", insn,
+ insn->type == INSN_JUMP_CONDITIONAL ? "-cond" : "");
+ }
+ return ret;
+ }
+
+ if (insn->type == INSN_JUMP_UNCONDITIONAL)
+ return 0;
+
+ break;
+ }
+
+ /* fallthrough */
+ case INSN_CALL:
+ dest = find_insn(file, insn->call_dest->sec,
+ insn->call_dest->offset);
+ if (!dest) {
+ WARN("Unresolved function after linking!?: %s",
+ insn->call_dest->name);
+ return -1;
+ }
+
+ ret = validate_entry(file, dest);
+ if (ret) {
+ if (backtrace)
+ BT_FUNC("(call)", insn);
+ return ret;
+ }
+ /*
+ * If a call returns without error, it must have seen UNTRAIN_RET.
+ * Therefore any non-error return is a success.
+ */
+ return 0;
+
+ case INSN_RETURN:
+ WARN_FUNC("RET before UNTRAIN", insn->sec, insn->offset);
+ return 1;
+
+ case INSN_NOP:
+ if (insn->retpoline_safe)
+ return 0;
+ break;
+
+ default:
+ break;
+ }
+
+ if (!next) {
+ WARN_FUNC("teh end!", insn->sec, insn->offset);
+ return -1;
+ }
+ insn = next;
+ }
+
+ return warnings;
+}
+
+/*
+ * Validate that all branches starting at 'insn->entry' encounter UNRET_END
+ * before RET.
+ */
+static int validate_unret(struct objtool_file *file)
+{
+ struct instruction *insn;
+ int ret, warnings = 0;
+
+ for_each_insn(file, insn) {
+ if (!insn->entry)
+ continue;
+
+ ret = validate_entry(file, insn);
+ if (ret < 0) {
+ WARN_FUNC("Failed UNRET validation", insn->sec, insn->offset);
+ return ret;
+ }
+ warnings += ret;
+ }
+
+ return warnings;
+}
+
static int validate_retpoline(struct objtool_file *file)
{
struct instruction *insn;
@@ -2692,7 +3245,8 @@ static int validate_retpoline(struct objtool_file *file)

for_each_insn(file, insn) {
if (insn->type != INSN_JUMP_DYNAMIC &&
- insn->type != INSN_CALL_DYNAMIC)
+ insn->type != INSN_CALL_DYNAMIC &&
+ insn->type != INSN_RETURN)
continue;

if (insn->retpoline_safe)
@@ -2707,9 +3261,17 @@ static int validate_retpoline(struct objtool_file *file)
if (!strcmp(insn->sec->name, ".init.text") && !module)
continue;

- WARN_FUNC("indirect %s found in RETPOLINE build",
- insn->sec, insn->offset,
- insn->type == INSN_JUMP_DYNAMIC ? "jump" : "call");
+ if (insn->type == INSN_RETURN) {
+ if (rethunk) {
+ WARN_FUNC("'naked' return found in RETHUNK build",
+ insn->sec, insn->offset);
+ } else
+ continue;
+ } else {
+ WARN_FUNC("indirect %s found in RETPOLINE build",
+ insn->sec, insn->offset,
+ insn->type == INSN_JUMP_DYNAMIC ? "jump" : "call");
+ }

warnings++;
}
@@ -2735,7 +3297,7 @@ static bool ignore_unreachable_insn(struct objtool_file *file, struct instructio
int i;
struct instruction *prev_insn;

- if (insn->ignore || insn->type == INSN_NOP)
+ if (insn->ignore || insn->type == INSN_NOP || insn->type == INSN_TRAP)
return true;

/*
@@ -2750,9 +3312,6 @@ static bool ignore_unreachable_insn(struct objtool_file *file, struct instructio
!strcmp(insn->sec->name, ".altinstr_aux"))
return true;

- if (insn->type == INSN_JUMP_UNCONDITIONAL && insn->offset == FAKE_JUMP_OFFSET)
- return true;
-
if (!insn->func)
return false;

@@ -2838,10 +3397,7 @@ static int validate_section(struct objtool_file *file, struct section *sec)
continue;

init_insn_state(&state, sec);
- state.cfi.cfa = initial_func_cfi.cfa;
- memcpy(&state.cfi.regs, &initial_func_cfi.regs,
- CFI_NUM_REGS * sizeof(struct cfi_reg));
- state.cfi.stack_size = initial_func_cfi.cfa.offset;
+ set_func_state(&state.cfi);

warnings += validate_symbol(file, sec, func, &state);
}
@@ -2907,10 +3463,20 @@ int check(struct objtool_file *file)
int ret, warnings = 0;

arch_initial_func_cfi_state(&initial_func_cfi);
+ init_cfi_state(&init_cfi);
+ init_cfi_state(&func_cfi);
+ set_func_state(&func_cfi);
+
+ if (!cfi_hash_alloc())
+ goto out;
+
+ cfi_hash_add(&init_cfi);
+ cfi_hash_add(&func_cfi);

ret = decode_sections(file);
if (ret < 0)
goto out;
+
warnings += ret;

if (list_empty(&file->insn_list))
@@ -2942,6 +3508,17 @@ int check(struct objtool_file *file)
goto out;
warnings += ret;

+ if (unret) {
+ /*
+ * Must be after validate_branch() and friends, it plays
+ * further games with insn->visited.
+ */
+ ret = validate_unret(file);
+ if (ret < 0)
+ return ret;
+ warnings += ret;
+ }
+
if (!warnings) {
ret = validate_reachable_instructions(file);
if (ret < 0)
@@ -2954,6 +3531,27 @@ int check(struct objtool_file *file)
goto out;
warnings += ret;

+ if (retpoline) {
+ ret = create_retpoline_sites_sections(file);
+ if (ret < 0)
+ goto out;
+ warnings += ret;
+ }
+
+ if (rethunk) {
+ ret = create_return_sites_sections(file);
+ if (ret < 0)
+ goto out;
+ warnings += ret;
+ }
+
+ if (stats) {
+ printf("nr_insns_visited: %ld\n", nr_insns_visited);
+ printf("nr_cfi: %ld\n", nr_cfi);
+ printf("nr_cfi_reused: %ld\n", nr_cfi_reused);
+ printf("nr_cfi_cache: %ld\n", nr_cfi_cache);
+ }
+
out:
/*
* For now, don't fail the kernel build on fatal warnings. These
diff --git a/tools/objtool/check.h b/tools/objtool/check.h
index 2804848e628e..7f34a7f9ca52 100644
--- a/tools/objtool/check.h
+++ b/tools/objtool/check.h
@@ -19,10 +19,27 @@ struct insn_state {
s8 instr;
};

+struct alt_group {
+ /*
+ * Pointer from a replacement group to the original group. NULL if it
+ * *is* the original group.
+ */
+ struct alt_group *orig_group;
+
+ /* First and last instructions in the group */
+ struct instruction *first_insn, *last_insn;
+
+ /*
+ * Byte-offset-addressed len-sized array of pointers to CFI structs.
+ * This is shared with the other alt_groups in the same alternative.
+ */
+ struct cfi_state **cfi;
+};
+
struct instruction {
struct list_head list;
struct hlist_node hash;
- struct list_head static_call_node;
+ struct list_head call_node;
struct section *sec;
unsigned long offset;
unsigned int len;
@@ -30,24 +47,28 @@ struct instruction {
unsigned long immediate;
bool dead_end, ignore, ignore_alts;
bool hint;
+ bool save, restore;
bool retpoline_safe;
+ bool entry;
s8 instr;
u8 visited;
- u8 ret_offset;
- int alt_group;
+ struct alt_group *alt_group;
struct symbol *call_dest;
struct instruction *jump_dest;
struct instruction *first_jump_src;
struct reloc *jump_table;
+ struct reloc *reloc;
struct list_head alts;
struct symbol *func;
struct list_head stack_ops;
- struct cfi_state cfi;
-#ifdef INSN_USE_ORC
- struct orc_entry orc;
-#endif
+ struct cfi_state *cfi;
};

+#define VISITED_BRANCH 0x01
+#define VISITED_BRANCH_UACCESS 0x02
+#define VISITED_BRANCH_MASK 0x03
+#define VISITED_ENTRY 0x04
+
static inline bool is_static_jump(struct instruction *insn)
{
return insn->type == INSN_JUMP_CONDITIONAL ||
diff --git a/tools/objtool/elf.c b/tools/objtool/elf.c
index d8421e1d06be..5aa3b4e76479 100644
--- a/tools/objtool/elf.c
+++ b/tools/objtool/elf.c
@@ -262,32 +262,6 @@ struct reloc *find_reloc_by_dest(const struct elf *elf, struct section *sec, uns
return find_reloc_by_dest_range(elf, sec, offset, 1);
}

-void insn_to_reloc_sym_addend(struct section *sec, unsigned long offset,
- struct reloc *reloc)
-{
- if (sec->sym) {
- reloc->sym = sec->sym;
- reloc->addend = offset;
- return;
- }
-
- /*
- * The Clang assembler strips section symbols, so we have to reference
- * the function symbol instead:
- */
- reloc->sym = find_symbol_containing(sec, offset);
- if (!reloc->sym) {
- /*
- * Hack alert. This happens when we need to reference the NOP
- * pad insn immediately after the function.
- */
- reloc->sym = find_symbol_containing(sec, offset - 1);
- }
-
- if (reloc->sym)
- reloc->addend = offset - reloc->sym->offset;
-}
-
static int read_sections(struct elf *elf)
{
Elf_Scn *s = NULL;
@@ -367,12 +341,41 @@ static int read_sections(struct elf *elf)
return 0;
}

+static void elf_add_symbol(struct elf *elf, struct symbol *sym)
+{
+ struct list_head *entry;
+ struct rb_node *pnode;
+
+ sym->alias = sym;
+
+ sym->type = GELF_ST_TYPE(sym->sym.st_info);
+ sym->bind = GELF_ST_BIND(sym->sym.st_info);
+
+ sym->offset = sym->sym.st_value;
+ sym->len = sym->sym.st_size;
+
+ rb_add(&sym->sec->symbol_tree, &sym->node, symbol_to_offset);
+ pnode = rb_prev(&sym->node);
+ if (pnode)
+ entry = &rb_entry(pnode, struct symbol, node)->list;
+ else
+ entry = &sym->sec->symbol_list;
+ list_add(&sym->list, entry);
+ elf_hash_add(elf->symbol_hash, &sym->hash, sym->idx);
+ elf_hash_add(elf->symbol_name_hash, &sym->name_hash, str_hash(sym->name));
+
+ /*
+ * Don't store empty STT_NOTYPE symbols in the rbtree. They
+ * can exist within a function, confusing the sorting.
+ */
+ if (!sym->len)
+ rb_erase(&sym->node, &sym->sec->symbol_tree);
+}
+
static int read_symbols(struct elf *elf)
{
struct section *symtab, *symtab_shndx, *sec;
struct symbol *sym, *pfunc;
- struct list_head *entry;
- struct rb_node *pnode;
int symbols_nr, i;
char *coldstr;
Elf_Data *shndx_data = NULL;
@@ -400,7 +403,6 @@ static int read_symbols(struct elf *elf)
return -1;
}
memset(sym, 0, sizeof(*sym));
- sym->alias = sym;

sym->idx = i;

@@ -417,9 +419,6 @@ static int read_symbols(struct elf *elf)
goto err;
}

- sym->type = GELF_ST_TYPE(sym->sym.st_info);
- sym->bind = GELF_ST_BIND(sym->sym.st_info);
-
if ((sym->sym.st_shndx > SHN_UNDEF &&
sym->sym.st_shndx < SHN_LORESERVE) ||
(shndx_data && sym->sym.st_shndx == SHN_XINDEX)) {
@@ -432,32 +431,14 @@ static int read_symbols(struct elf *elf)
sym->name);
goto err;
}
- if (sym->type == STT_SECTION) {
+ if (GELF_ST_TYPE(sym->sym.st_info) == STT_SECTION) {
sym->name = sym->sec->name;
sym->sec->sym = sym;
}
} else
sym->sec = find_section_by_index(elf, 0);

- sym->offset = sym->sym.st_value;
- sym->len = sym->sym.st_size;
-
- rb_add(&sym->sec->symbol_tree, &sym->node, symbol_to_offset);
- pnode = rb_prev(&sym->node);
- if (pnode)
- entry = &rb_entry(pnode, struct symbol, node)->list;
- else
- entry = &sym->sec->symbol_list;
- list_add(&sym->list, entry);
- elf_hash_add(elf->symbol_hash, &sym->hash, sym->idx);
- elf_hash_add(elf->symbol_name_hash, &sym->name_hash, str_hash(sym->name));
-
- /*
- * Don't store empty STT_NOTYPE symbols in the rbtree. They
- * can exist within a function, confusing the sorting.
- */
- if (!sym->len)
- rb_erase(&sym->node, &sym->sec->symbol_tree);
+ elf_add_symbol(elf, sym);
}

if (stats)
@@ -524,12 +505,275 @@ static int read_symbols(struct elf *elf)
return -1;
}

-void elf_add_reloc(struct elf *elf, struct reloc *reloc)
+static struct section *elf_create_reloc_section(struct elf *elf,
+ struct section *base,
+ int reltype);
+
+int elf_add_reloc(struct elf *elf, struct section *sec, unsigned long offset,
+ unsigned int type, struct symbol *sym, s64 addend)
{
- struct section *sec = reloc->sec;
+ struct reloc *reloc;
+
+ if (!sec->reloc && !elf_create_reloc_section(elf, sec, SHT_RELA))
+ return -1;

- list_add_tail(&reloc->list, &sec->reloc_list);
+ reloc = malloc(sizeof(*reloc));
+ if (!reloc) {
+ perror("malloc");
+ return -1;
+ }
+ memset(reloc, 0, sizeof(*reloc));
+
+ reloc->sec = sec->reloc;
+ reloc->offset = offset;
+ reloc->type = type;
+ reloc->sym = sym;
+ reloc->addend = addend;
+
+ list_add_tail(&reloc->list, &sec->reloc->reloc_list);
elf_hash_add(elf->reloc_hash, &reloc->hash, reloc_hash(reloc));
+
+ sec->reloc->changed = true;
+
+ return 0;
+}
+
+/*
+ * Ensure that any reloc section containing references to @sym is marked
+ * changed such that it will get re-generated in elf_rebuild_reloc_sections()
+ * with the new symbol index.
+ */
+static void elf_dirty_reloc_sym(struct elf *elf, struct symbol *sym)
+{
+ struct section *sec;
+
+ list_for_each_entry(sec, &elf->sections, list) {
+ struct reloc *reloc;
+
+ if (sec->changed)
+ continue;
+
+ list_for_each_entry(reloc, &sec->reloc_list, list) {
+ if (reloc->sym == sym) {
+ sec->changed = true;
+ break;
+ }
+ }
+ }
+}
+
+/*
+ * The libelf API is terrible; gelf_update_sym*() takes a data block relative
+ * index value, *NOT* the symbol index. As such, iterate the data blocks and
+ * adjust index until it fits.
+ *
+ * If no data block is found, allow adding a new data block provided the index
+ * is only one past the end.
+ */
+static int elf_update_symbol(struct elf *elf, struct section *symtab,
+ struct section *symtab_shndx, struct symbol *sym)
+{
+ Elf32_Word shndx = sym->sec ? sym->sec->idx : SHN_UNDEF;
+ Elf_Data *symtab_data = NULL, *shndx_data = NULL;
+ Elf64_Xword entsize = symtab->sh.sh_entsize;
+ int max_idx, idx = sym->idx;
+ Elf_Scn *s, *t = NULL;
+
+ s = elf_getscn(elf->elf, symtab->idx);
+ if (!s) {
+ WARN_ELF("elf_getscn");
+ return -1;
+ }
+
+ if (symtab_shndx) {
+ t = elf_getscn(elf->elf, symtab_shndx->idx);
+ if (!t) {
+ WARN_ELF("elf_getscn");
+ return -1;
+ }
+ }
+
+ for (;;) {
+ /* get next data descriptor for the relevant sections */
+ symtab_data = elf_getdata(s, symtab_data);
+ if (t)
+ shndx_data = elf_getdata(t, shndx_data);
+
+ /* end-of-list */
+ if (!symtab_data) {
+ void *buf;
+
+ if (idx) {
+ /* we don't do holes in symbol tables */
+ WARN("index out of range");
+ return -1;
+ }
+
+ /* if @idx == 0, it's the next contiguous entry, create it */
+ symtab_data = elf_newdata(s);
+ if (t)
+ shndx_data = elf_newdata(t);
+
+ buf = calloc(1, entsize);
+ if (!buf) {
+ WARN("malloc");
+ return -1;
+ }
+
+ symtab_data->d_buf = buf;
+ symtab_data->d_size = entsize;
+ symtab_data->d_align = 1;
+ symtab_data->d_type = ELF_T_SYM;
+
+ symtab->sh.sh_size += entsize;
+ symtab->changed = true;
+
+ if (t) {
+ shndx_data->d_buf = &sym->sec->idx;
+ shndx_data->d_size = sizeof(Elf32_Word);
+ shndx_data->d_align = sizeof(Elf32_Word);
+ shndx_data->d_type = ELF_T_WORD;
+
+ symtab_shndx->sh.sh_size += sizeof(Elf32_Word);
+ symtab_shndx->changed = true;
+ }
+
+ break;
+ }
+
+ /* empty blocks should not happen */
+ if (!symtab_data->d_size) {
+ WARN("zero size data");
+ return -1;
+ }
+
+ /* is this the right block? */
+ max_idx = symtab_data->d_size / entsize;
+ if (idx < max_idx)
+ break;
+
+ /* adjust index and try again */
+ idx -= max_idx;
+ }
+
+ /* something went side-ways */
+ if (idx < 0) {
+ WARN("negative index");
+ return -1;
+ }
+
+ /* setup extended section index magic and write the symbol */
+ if (shndx >= SHN_UNDEF && shndx < SHN_LORESERVE) {
+ sym->sym.st_shndx = shndx;
+ if (!shndx_data)
+ shndx = 0;
+ } else {
+ sym->sym.st_shndx = SHN_XINDEX;
+ if (!shndx_data) {
+ WARN("no .symtab_shndx");
+ return -1;
+ }
+ }
+
+ if (!gelf_update_symshndx(symtab_data, shndx_data, idx, &sym->sym, shndx)) {
+ WARN_ELF("gelf_update_symshndx");
+ return -1;
+ }
+
+ return 0;
+}
+
+static struct symbol *
+elf_create_section_symbol(struct elf *elf, struct section *sec)
+{
+ struct section *symtab, *symtab_shndx;
+ Elf32_Word first_non_local, new_idx;
+ struct symbol *sym, *old;
+
+ symtab = find_section_by_name(elf, ".symtab");
+ if (symtab) {
+ symtab_shndx = find_section_by_name(elf, ".symtab_shndx");
+ } else {
+ WARN("no .symtab");
+ return NULL;
+ }
+
+ sym = calloc(1, sizeof(*sym));
+ if (!sym) {
+ perror("malloc");
+ return NULL;
+ }
+
+ sym->name = sec->name;
+ sym->sec = sec;
+
+ // st_name 0
+ sym->sym.st_info = GELF_ST_INFO(STB_LOCAL, STT_SECTION);
+ // st_other 0
+ // st_value 0
+ // st_size 0
+
+ /*
+ * Move the first global symbol, as per sh_info, into a new, higher
+ * symbol index. This fees up a spot for a new local symbol.
+ */
+ first_non_local = symtab->sh.sh_info;
+ new_idx = symtab->sh.sh_size / symtab->sh.sh_entsize;
+ old = find_symbol_by_index(elf, first_non_local);
+ if (old) {
+ old->idx = new_idx;
+
+ hlist_del(&old->hash);
+ elf_hash_add(elf->symbol_hash, &old->hash, old->idx);
+
+ elf_dirty_reloc_sym(elf, old);
+
+ if (elf_update_symbol(elf, symtab, symtab_shndx, old)) {
+ WARN("elf_update_symbol move");
+ return NULL;
+ }
+
+ new_idx = first_non_local;
+ }
+
+ sym->idx = new_idx;
+ if (elf_update_symbol(elf, symtab, symtab_shndx, sym)) {
+ WARN("elf_update_symbol");
+ return NULL;
+ }
+
+ /*
+ * Either way, we added a LOCAL symbol.
+ */
+ symtab->sh.sh_info += 1;
+
+ elf_add_symbol(elf, sym);
+
+ return sym;
+}
+
+int elf_add_reloc_to_insn(struct elf *elf, struct section *sec,
+ unsigned long offset, unsigned int type,
+ struct section *insn_sec, unsigned long insn_off)
+{
+ struct symbol *sym = insn_sec->sym;
+ int addend = insn_off;
+
+ if (!sym) {
+ /*
+ * Due to how weak functions work, we must use section based
+ * relocations. Symbol based relocations would result in the
+ * weak and non-weak function annotations being overlaid on the
+ * non-weak function after linking.
+ */
+ sym = elf_create_section_symbol(elf, insn_sec);
+ if (!sym)
+ return -1;
+
+ insn_sec->sym = sym;
+ }
+
+ return elf_add_reloc(elf, sec, offset, type, sym, addend);
}

static int read_rel_reloc(struct section *sec, int i, struct reloc *reloc, unsigned int *symndx)
@@ -609,7 +853,9 @@ static int read_relocs(struct elf *elf)
return -1;
}

- elf_add_reloc(elf, reloc);
+ list_add_tail(&reloc->list, &sec->reloc_list);
+ elf_hash_add(elf->reloc_hash, &reloc->hash, reloc_hash(reloc));
+
nr_reloc++;
}
max_reloc = max(max_reloc, nr_reloc);
@@ -687,13 +933,49 @@ struct elf *elf_open_read(const char *name, int flags)
return NULL;
}

+static int elf_add_string(struct elf *elf, struct section *strtab, char *str)
+{
+ Elf_Data *data;
+ Elf_Scn *s;
+ int len;
+
+ if (!strtab)
+ strtab = find_section_by_name(elf, ".strtab");
+ if (!strtab) {
+ WARN("can't find .strtab section");
+ return -1;
+ }
+
+ s = elf_getscn(elf->elf, strtab->idx);
+ if (!s) {
+ WARN_ELF("elf_getscn");
+ return -1;
+ }
+
+ data = elf_newdata(s);
+ if (!data) {
+ WARN_ELF("elf_newdata");
+ return -1;
+ }
+
+ data->d_buf = str;
+ data->d_size = strlen(str) + 1;
+ data->d_align = 1;
+ data->d_type = ELF_T_SYM;
+
+ len = strtab->len;
+ strtab->len += data->d_size;
+ strtab->changed = true;
+
+ return len;
+}
+
struct section *elf_create_section(struct elf *elf, const char *name,
unsigned int sh_flags, size_t entsize, int nr)
{
struct section *sec, *shstrtab;
size_t size = entsize * nr;
Elf_Scn *s;
- Elf_Data *data;

sec = malloc(sizeof(*sec));
if (!sec) {
@@ -750,7 +1032,6 @@ struct section *elf_create_section(struct elf *elf, const char *name,
sec->sh.sh_addralign = 1;
sec->sh.sh_flags = SHF_ALLOC | sh_flags;

-
/* Add section name to .shstrtab (or .strtab for Clang) */
shstrtab = find_section_by_name(elf, ".shstrtab");
if (!shstrtab)
@@ -759,27 +1040,9 @@ struct section *elf_create_section(struct elf *elf, const char *name,
WARN("can't find .shstrtab or .strtab section");
return NULL;
}
-
- s = elf_getscn(elf->elf, shstrtab->idx);
- if (!s) {
- WARN_ELF("elf_getscn");
- return NULL;
- }
-
- data = elf_newdata(s);
- if (!data) {
- WARN_ELF("elf_newdata");
+ sec->sh.sh_name = elf_add_string(elf, shstrtab, sec->name);
+ if (sec->sh.sh_name == -1)
return NULL;
- }
-
- data->d_buf = sec->name;
- data->d_size = strlen(name) + 1;
- data->d_align = 1;
-
- sec->sh.sh_name = shstrtab->len;
-
- shstrtab->len += strlen(name) + 1;
- shstrtab->changed = true;

list_add_tail(&sec->list, &elf->sections);
elf_hash_add(elf->section_hash, &sec->hash, sec->idx);
@@ -850,7 +1113,7 @@ static struct section *elf_create_rela_reloc_section(struct elf *elf, struct sec
return sec;
}

-struct section *elf_create_reloc_section(struct elf *elf,
+static struct section *elf_create_reloc_section(struct elf *elf,
struct section *base,
int reltype)
{
@@ -920,14 +1183,11 @@ static int elf_rebuild_rela_reloc_section(struct section *sec, int nr)
return 0;
}

-int elf_rebuild_reloc_section(struct elf *elf, struct section *sec)
+static int elf_rebuild_reloc_section(struct elf *elf, struct section *sec)
{
struct reloc *reloc;
int nr;

- sec->changed = true;
- elf->changed = true;
-
nr = 0;
list_for_each_entry(reloc, &sec->reloc_list, list)
nr++;
@@ -991,9 +1251,15 @@ int elf_write(struct elf *elf)
struct section *sec;
Elf_Scn *s;

- /* Update section headers for changed sections: */
+ /* Update changed relocation sections and section headers: */
list_for_each_entry(sec, &elf->sections, list) {
if (sec->changed) {
+ if (sec->base &&
+ elf_rebuild_reloc_section(elf, sec)) {
+ WARN("elf_rebuild_reloc_section");
+ return -1;
+ }
+
s = elf_getscn(elf->elf, sec->idx);
if (!s) {
WARN_ELF("elf_getscn");
@@ -1005,6 +1271,7 @@ int elf_write(struct elf *elf)
}

sec->changed = false;
+ elf->changed = true;
}
}

diff --git a/tools/objtool/elf.h b/tools/objtool/elf.h
index e6890cc70a25..a1863eb35fbb 100644
--- a/tools/objtool/elf.h
+++ b/tools/objtool/elf.h
@@ -55,8 +55,12 @@ struct symbol {
unsigned long offset;
unsigned int len;
struct symbol *pfunc, *cfunc, *alias;
- bool uaccess_safe;
- bool static_call_tramp;
+ u8 uaccess_safe : 1;
+ u8 static_call_tramp : 1;
+ u8 retpoline_thunk : 1;
+ u8 return_thunk : 1;
+ u8 fentry : 1;
+ u8 kcov : 1;
};

struct reloc {
@@ -70,7 +74,7 @@ struct reloc {
struct symbol *sym;
unsigned long offset;
unsigned int type;
- int addend;
+ s64 addend;
int idx;
bool jump_table_start;
};
@@ -122,8 +126,13 @@ static inline u32 reloc_hash(struct reloc *reloc)

struct elf *elf_open_read(const char *name, int flags);
struct section *elf_create_section(struct elf *elf, const char *name, unsigned int sh_flags, size_t entsize, int nr);
-struct section *elf_create_reloc_section(struct elf *elf, struct section *base, int reltype);
-void elf_add_reloc(struct elf *elf, struct reloc *reloc);
+
+int elf_add_reloc(struct elf *elf, struct section *sec, unsigned long offset,
+ unsigned int type, struct symbol *sym, s64 addend);
+int elf_add_reloc_to_insn(struct elf *elf, struct section *sec,
+ unsigned long offset, unsigned int type,
+ struct section *insn_sec, unsigned long insn_off);
+
int elf_write_insn(struct elf *elf, struct section *sec,
unsigned long offset, unsigned int len,
const char *insn);
@@ -140,9 +149,6 @@ struct reloc *find_reloc_by_dest(const struct elf *elf, struct section *sec, uns
struct reloc *find_reloc_by_dest_range(const struct elf *elf, struct section *sec,
unsigned long offset, unsigned int len);
struct symbol *find_func_containing(struct section *sec, unsigned long offset);
-void insn_to_reloc_sym_addend(struct section *sec, unsigned long offset,
- struct reloc *reloc);
-int elf_rebuild_reloc_section(struct elf *elf, struct section *sec);

#define for_each_sec(file, sec) \
list_for_each_entry(sec, &file->elf->sections, list)
diff --git a/tools/objtool/objtool.c b/tools/objtool/objtool.c
index 9df0cd86d310..cb2c6acd9667 100644
--- a/tools/objtool/objtool.c
+++ b/tools/objtool/objtool.c
@@ -61,6 +61,8 @@ struct objtool_file *objtool_open_read(const char *_objname)

INIT_LIST_HEAD(&file.insn_list);
hash_init(file.insn_hash);
+ INIT_LIST_HEAD(&file.retpoline_call_list);
+ INIT_LIST_HEAD(&file.return_thunk_list);
INIT_LIST_HEAD(&file.static_call_list);
file.c_file = !vmlinux && find_section_by_name(file.elf, ".comment");
file.ignore_unreachables = no_unreachable;
diff --git a/tools/objtool/objtool.h b/tools/objtool/objtool.h
index 4125d4578b23..bf64946e749b 100644
--- a/tools/objtool/objtool.h
+++ b/tools/objtool/objtool.h
@@ -18,6 +18,8 @@ struct objtool_file {
struct elf *elf;
struct list_head insn_list;
DECLARE_HASHTABLE(insn_hash, 20);
+ struct list_head retpoline_call_list;
+ struct list_head return_thunk_list;
struct list_head static_call_list;
bool ignore_unreachables, c_file, hints, rodata;
};
@@ -26,7 +28,6 @@ struct objtool_file *objtool_open_read(const char *_objname);

int check(struct objtool_file *file);
int orc_dump(const char *objname);
-int create_orc(struct objtool_file *file);
-int create_orc_sections(struct objtool_file *file);
+int orc_create(struct objtool_file *file);

#endif /* _OBJTOOL_H */
diff --git a/tools/objtool/orc_gen.c b/tools/objtool/orc_gen.c
index 9ce68b385a1b..812b33ed9f65 100644
--- a/tools/objtool/orc_gen.c
+++ b/tools/objtool/orc_gen.c
@@ -12,205 +12,231 @@
#include "check.h"
#include "warn.h"

-int create_orc(struct objtool_file *file)
+static int init_orc_entry(struct orc_entry *orc, struct cfi_state *cfi,
+ struct instruction *insn)
{
- struct instruction *insn;
+ struct cfi_reg *bp = &cfi->regs[CFI_BP];

- for_each_insn(file, insn) {
- struct orc_entry *orc = &insn->orc;
- struct cfi_reg *cfa = &insn->cfi.cfa;
- struct cfi_reg *bp = &insn->cfi.regs[CFI_BP];
+ memset(orc, 0, sizeof(*orc));

- if (!insn->sec->text)
- continue;
-
- orc->end = insn->cfi.end;
+ if (!cfi) {
+ orc->end = 0;
+ orc->sp_reg = ORC_REG_UNDEFINED;
+ return 0;
+ }

- if (cfa->base == CFI_UNDEFINED) {
- orc->sp_reg = ORC_REG_UNDEFINED;
- continue;
- }
+ orc->end = cfi->end;

- switch (cfa->base) {
- case CFI_SP:
- orc->sp_reg = ORC_REG_SP;
- break;
- case CFI_SP_INDIRECT:
- orc->sp_reg = ORC_REG_SP_INDIRECT;
- break;
- case CFI_BP:
- orc->sp_reg = ORC_REG_BP;
- break;
- case CFI_BP_INDIRECT:
- orc->sp_reg = ORC_REG_BP_INDIRECT;
- break;
- case CFI_R10:
- orc->sp_reg = ORC_REG_R10;
- break;
- case CFI_R13:
- orc->sp_reg = ORC_REG_R13;
- break;
- case CFI_DI:
- orc->sp_reg = ORC_REG_DI;
- break;
- case CFI_DX:
- orc->sp_reg = ORC_REG_DX;
- break;
- default:
- WARN_FUNC("unknown CFA base reg %d",
- insn->sec, insn->offset, cfa->base);
- return -1;
- }
+ if (cfi->cfa.base == CFI_UNDEFINED) {
+ orc->sp_reg = ORC_REG_UNDEFINED;
+ return 0;
+ }

- switch(bp->base) {
- case CFI_UNDEFINED:
- orc->bp_reg = ORC_REG_UNDEFINED;
- break;
- case CFI_CFA:
- orc->bp_reg = ORC_REG_PREV_SP;
- break;
- case CFI_BP:
- orc->bp_reg = ORC_REG_BP;
- break;
- default:
- WARN_FUNC("unknown BP base reg %d",
- insn->sec, insn->offset, bp->base);
- return -1;
- }
+ switch (cfi->cfa.base) {
+ case CFI_SP:
+ orc->sp_reg = ORC_REG_SP;
+ break;
+ case CFI_SP_INDIRECT:
+ orc->sp_reg = ORC_REG_SP_INDIRECT;
+ break;
+ case CFI_BP:
+ orc->sp_reg = ORC_REG_BP;
+ break;
+ case CFI_BP_INDIRECT:
+ orc->sp_reg = ORC_REG_BP_INDIRECT;
+ break;
+ case CFI_R10:
+ orc->sp_reg = ORC_REG_R10;
+ break;
+ case CFI_R13:
+ orc->sp_reg = ORC_REG_R13;
+ break;
+ case CFI_DI:
+ orc->sp_reg = ORC_REG_DI;
+ break;
+ case CFI_DX:
+ orc->sp_reg = ORC_REG_DX;
+ break;
+ default:
+ WARN_FUNC("unknown CFA base reg %d",
+ insn->sec, insn->offset, cfi->cfa.base);
+ return -1;
+ }

- orc->sp_offset = cfa->offset;
- orc->bp_offset = bp->offset;
- orc->type = insn->cfi.type;
+ switch (bp->base) {
+ case CFI_UNDEFINED:
+ orc->bp_reg = ORC_REG_UNDEFINED;
+ break;
+ case CFI_CFA:
+ orc->bp_reg = ORC_REG_PREV_SP;
+ break;
+ case CFI_BP:
+ orc->bp_reg = ORC_REG_BP;
+ break;
+ default:
+ WARN_FUNC("unknown BP base reg %d",
+ insn->sec, insn->offset, bp->base);
+ return -1;
}

+ orc->sp_offset = cfi->cfa.offset;
+ orc->bp_offset = bp->offset;
+ orc->type = cfi->type;
+
return 0;
}

-static int create_orc_entry(struct elf *elf, struct section *u_sec, struct section *ip_relocsec,
- unsigned int idx, struct section *insn_sec,
- unsigned long insn_off, struct orc_entry *o)
+static int write_orc_entry(struct elf *elf, struct section *orc_sec,
+ struct section *ip_sec, unsigned int idx,
+ struct section *insn_sec, unsigned long insn_off,
+ struct orc_entry *o)
{
struct orc_entry *orc;
- struct reloc *reloc;

/* populate ORC data */
- orc = (struct orc_entry *)u_sec->data->d_buf + idx;
+ orc = (struct orc_entry *)orc_sec->data->d_buf + idx;
memcpy(orc, o, sizeof(*orc));

/* populate reloc for ip */
- reloc = malloc(sizeof(*reloc));
- if (!reloc) {
- perror("malloc");
+ if (elf_add_reloc_to_insn(elf, ip_sec, idx * sizeof(int), R_X86_64_PC32,
+ insn_sec, insn_off))
return -1;
- }
- memset(reloc, 0, sizeof(*reloc));

- insn_to_reloc_sym_addend(insn_sec, insn_off, reloc);
- if (!reloc->sym) {
- WARN("missing symbol for insn at offset 0x%lx",
- insn_off);
+ return 0;
+}
+
+struct orc_list_entry {
+ struct list_head list;
+ struct orc_entry orc;
+ struct section *insn_sec;
+ unsigned long insn_off;
+};
+
+static int orc_list_add(struct list_head *orc_list, struct orc_entry *orc,
+ struct section *sec, unsigned long offset)
+{
+ struct orc_list_entry *entry = malloc(sizeof(*entry));
+
+ if (!entry) {
+ WARN("malloc failed");
return -1;
}

- reloc->type = R_X86_64_PC32;
- reloc->offset = idx * sizeof(int);
- reloc->sec = ip_relocsec;
-
- elf_add_reloc(elf, reloc);
+ entry->orc = *orc;
+ entry->insn_sec = sec;
+ entry->insn_off = offset;

+ list_add_tail(&entry->list, orc_list);
return 0;
}

-int create_orc_sections(struct objtool_file *file)
+static unsigned long alt_group_len(struct alt_group *alt_group)
+{
+ return alt_group->last_insn->offset +
+ alt_group->last_insn->len -
+ alt_group->first_insn->offset;
+}
+
+int orc_create(struct objtool_file *file)
{
- struct instruction *insn, *prev_insn;
- struct section *sec, *u_sec, *ip_relocsec;
- unsigned int idx;
+ struct section *sec, *orc_sec;
+ unsigned int nr = 0, idx = 0;
+ struct orc_list_entry *entry;
+ struct list_head orc_list;

- struct orc_entry empty = {
- .sp_reg = ORC_REG_UNDEFINED,
+ struct orc_entry null = {
+ .sp_reg = ORC_REG_UNDEFINED,
.bp_reg = ORC_REG_UNDEFINED,
.type = UNWIND_HINT_TYPE_CALL,
};

- sec = find_section_by_name(file->elf, ".orc_unwind");
- if (sec) {
- WARN("file already has .orc_unwind section, skipping");
- return -1;
- }
-
- /* count the number of needed orcs */
- idx = 0;
+ /* Build a deduplicated list of ORC entries: */
+ INIT_LIST_HEAD(&orc_list);
for_each_sec(file, sec) {
- if (!sec->text)
- continue;
+ struct orc_entry orc, prev_orc = {0};
+ struct instruction *insn;
+ bool empty = true;

- prev_insn = NULL;
- sec_for_each_insn(file, sec, insn) {
- if (!prev_insn ||
- memcmp(&insn->orc, &prev_insn->orc,
- sizeof(struct orc_entry))) {
- idx++;
- }
- prev_insn = insn;
- }
-
- /* section terminator */
- if (prev_insn)
- idx++;
- }
- if (!idx)
- return -1;
-
-
- /* create .orc_unwind_ip and .rela.orc_unwind_ip sections */
- sec = elf_create_section(file->elf, ".orc_unwind_ip", 0, sizeof(int), idx);
- if (!sec)
- return -1;
-
- ip_relocsec = elf_create_reloc_section(file->elf, sec, SHT_RELA);
- if (!ip_relocsec)
- return -1;
-
- /* create .orc_unwind section */
- u_sec = elf_create_section(file->elf, ".orc_unwind", 0,
- sizeof(struct orc_entry), idx);
-
- /* populate sections */
- idx = 0;
- for_each_sec(file, sec) {
if (!sec->text)
continue;

- prev_insn = NULL;
sec_for_each_insn(file, sec, insn) {
- if (!prev_insn || memcmp(&insn->orc, &prev_insn->orc,
- sizeof(struct orc_entry))) {
+ struct alt_group *alt_group = insn->alt_group;
+ int i;

- if (create_orc_entry(file->elf, u_sec, ip_relocsec, idx,
- insn->sec, insn->offset,
- &insn->orc))
+ if (!alt_group) {
+ if (init_orc_entry(&orc, insn->cfi, insn))
+ return -1;
+ if (!memcmp(&prev_orc, &orc, sizeof(orc)))
+ continue;
+ if (orc_list_add(&orc_list, &orc, sec,
+ insn->offset))
return -1;
+ nr++;
+ prev_orc = orc;
+ empty = false;
+ continue;
+ }

- idx++;
+ /*
+ * Alternatives can have different stack layout
+ * possibilities (but they shouldn't conflict).
+ * Instead of traversing the instructions, use the
+ * alt_group's flattened byte-offset-addressed CFI
+ * array.
+ */
+ for (i = 0; i < alt_group_len(alt_group); i++) {
+ struct cfi_state *cfi = alt_group->cfi[i];
+ if (!cfi)
+ continue;
+ /* errors are reported on the original insn */
+ if (init_orc_entry(&orc, cfi, insn))
+ return -1;
+ if (!memcmp(&prev_orc, &orc, sizeof(orc)))
+ continue;
+ if (orc_list_add(&orc_list, &orc, insn->sec,
+ insn->offset + i))
+ return -1;
+ nr++;
+ prev_orc = orc;
+ empty = false;
}
- prev_insn = insn;
- }

- /* section terminator */
- if (prev_insn) {
- if (create_orc_entry(file->elf, u_sec, ip_relocsec, idx,
- prev_insn->sec,
- prev_insn->offset + prev_insn->len,
- &empty))
- return -1;
+ /* Skip to the end of the alt_group */
+ insn = alt_group->last_insn;
+ }

- idx++;
+ /* Add a section terminator */
+ if (!empty) {
+ orc_list_add(&orc_list, &null, sec, sec->len);
+ nr++;
}
}
+ if (!nr)
+ return 0;
+
+ /* Create .orc_unwind, .orc_unwind_ip and .rela.orc_unwind_ip sections: */
+ sec = find_section_by_name(file->elf, ".orc_unwind");
+ if (sec) {
+ WARN("file already has .orc_unwind section, skipping");
+ return -1;
+ }
+ orc_sec = elf_create_section(file->elf, ".orc_unwind", 0,
+ sizeof(struct orc_entry), nr);
+ if (!orc_sec)
+ return -1;

- if (elf_rebuild_reloc_section(file->elf, ip_relocsec))
+ sec = elf_create_section(file->elf, ".orc_unwind_ip", 0, sizeof(int), nr);
+ if (!sec)
return -1;

+ /* Write ORC entries to sections: */
+ list_for_each_entry(entry, &orc_list, list) {
+ if (write_orc_entry(file->elf, orc_sec, sec, idx++,
+ entry->insn_sec, entry->insn_off,
+ &entry->orc))
+ return -1;
+ }
+
return 0;
}
diff --git a/tools/objtool/special.c b/tools/objtool/special.c
index 1a2420febd08..aff0cee7bac1 100644
--- a/tools/objtool/special.c
+++ b/tools/objtool/special.c
@@ -55,6 +55,13 @@ void __weak arch_handle_alternative(unsigned short feature, struct special_alt *
{
}

+static void reloc_to_sec_off(struct reloc *reloc, struct section **sec,
+ unsigned long *off)
+{
+ *sec = reloc->sym->sec;
+ *off = reloc->sym->offset + reloc->addend;
+}
+
static int get_alt_entry(struct elf *elf, struct special_entry *entry,
struct section *sec, int idx,
struct special_alt *alt)
@@ -87,14 +94,8 @@ static int get_alt_entry(struct elf *elf, struct special_entry *entry,
WARN_FUNC("can't find orig reloc", sec, offset + entry->orig);
return -1;
}
- if (orig_reloc->sym->type != STT_SECTION) {
- WARN_FUNC("don't know how to handle non-section reloc symbol %s",
- sec, offset + entry->orig, orig_reloc->sym->name);
- return -1;
- }

- alt->orig_sec = orig_reloc->sym->sec;
- alt->orig_off = orig_reloc->addend;
+ reloc_to_sec_off(orig_reloc, &alt->orig_sec, &alt->orig_off);

if (!entry->group || alt->new_len) {
new_reloc = find_reloc_by_dest(elf, sec, offset + entry->new);
@@ -104,8 +105,7 @@ static int get_alt_entry(struct elf *elf, struct special_entry *entry,
return -1;
}

- alt->new_sec = new_reloc->sym->sec;
- alt->new_off = (unsigned int)new_reloc->addend;
+ reloc_to_sec_off(new_reloc, &alt->new_sec, &alt->new_off);

/* _ASM_EXTABLE_EX hack */
if (alt->new_off >= 0x7ffffff0)
@@ -152,7 +152,9 @@ int special_get_alts(struct elf *elf, struct list_head *alts)
memset(alt, 0, sizeof(*alt));

ret = get_alt_entry(elf, entry, sec, idx, alt);
- if (ret)
+ if (ret > 0)
+ continue;
+ if (ret < 0)
return ret;

list_add_tail(&alt->list, alts);
diff --git a/tools/objtool/sync-check.sh b/tools/objtool/sync-check.sh
index 606a4b5e929f..4bbabaecab14 100755
--- a/tools/objtool/sync-check.sh
+++ b/tools/objtool/sync-check.sh
@@ -16,11 +16,14 @@ arch/x86/include/asm/emulate_prefix.h
arch/x86/lib/x86-opcode-map.txt
arch/x86/tools/gen-insn-attr-x86.awk
include/linux/static_call_types.h
-arch/x86/include/asm/inat.h -I '^#include [\"<]\(asm/\)*inat_types.h[\">]'
-arch/x86/include/asm/insn.h -I '^#include [\"<]\(asm/\)*inat.h[\">]'
-arch/x86/lib/inat.c -I '^#include [\"<]\(../include/\)*asm/insn.h[\">]'
-arch/x86/lib/insn.c -I '^#include [\"<]\(../include/\)*asm/in\(at\|sn\).h[\">]' -I '^#include [\"<]\(../include/\)*asm/emulate_prefix.h[\">]'
"
+
+SYNC_CHECK_FILES='
+arch/x86/include/asm/inat.h
+arch/x86/include/asm/insn.h
+arch/x86/lib/inat.c
+arch/x86/lib/insn.c
+'
fi

check_2 () {
@@ -63,3 +66,9 @@ while read -r file_entry; do
done <<EOF
$FILES
EOF
+
+if [ "$SRCARCH" = "x86" ]; then
+ for i in $SYNC_CHECK_FILES; do
+ check $i '-I "^.*\/\*.*__ignore_sync_check__.*\*\/.*$"'
+ done
+fi
diff --git a/tools/objtool/weak.c b/tools/objtool/weak.c
index 7843e9a7a72f..553ec9ce51ba 100644
--- a/tools/objtool/weak.c
+++ b/tools/objtool/weak.c
@@ -25,12 +25,7 @@ int __weak orc_dump(const char *_objname)
UNSUPPORTED("orc");
}

-int __weak create_orc(struct objtool_file *file)
-{
- UNSUPPORTED("orc");
-}
-
-int __weak create_orc_sections(struct objtool_file *file)
+int __weak orc_create(struct objtool_file *file)
{
UNSUPPORTED("orc");
}
diff --git a/tools/perf/check-headers.sh b/tools/perf/check-headers.sh
index 15ecb1803fb9..9f085aa09c97 100755
--- a/tools/perf/check-headers.sh
+++ b/tools/perf/check-headers.sh
@@ -75,6 +75,13 @@ include/uapi/asm-generic/mman-common.h
include/uapi/asm-generic/unistd.h
'

+SYNC_CHECK_FILES='
+arch/x86/include/asm/inat.h
+arch/x86/include/asm/insn.h
+arch/x86/lib/inat.c
+arch/x86/lib/insn.c
+'
+
# These copies are under tools/perf/trace/beauty/ as they are not used to in
# building object files only by scripts in tools/perf/trace/beauty/ to generate
# tables that then gets included in .c files for things like id->string syscall
@@ -129,6 +136,10 @@ for i in $FILES; do
check $i -B
done

+for i in $SYNC_CHECK_FILES; do
+ check $i '-I "^.*\/\*.*__ignore_sync_check__.*\*\/.*$"'
+done
+
# diff with extra ignore lines
check arch/x86/lib/memcpy_64.S '-I "^EXPORT_SYMBOL" -I "^#include <asm/export.h>" -I"^SYM_FUNC_START\(_LOCAL\)*(memcpy_\(erms\|orig\))"'
check arch/x86/lib/memset_64.S '-I "^EXPORT_SYMBOL" -I "^#include <asm/export.h>" -I"^SYM_FUNC_START\(_LOCAL\)*(memset_\(erms\|orig\))"'
@@ -137,10 +148,6 @@ check include/uapi/linux/mman.h '-I "^#include <\(uapi/\)*asm/mman.h>"'
check include/linux/build_bug.h '-I "^#\(ifndef\|endif\)\( \/\/\)* static_assert$"'
check include/linux/ctype.h '-I "isdigit("'
check lib/ctype.c '-I "^EXPORT_SYMBOL" -I "^#include <linux/export.h>" -B'
-check arch/x86/include/asm/inat.h '-I "^#include [\"<]\(asm/\)*inat_types.h[\">]"'
-check arch/x86/include/asm/insn.h '-I "^#include [\"<]\(asm/\)*inat.h[\">]"'
-check arch/x86/lib/inat.c '-I "^#include [\"<]\(../include/\)*asm/insn.h[\">]"'
-check arch/x86/lib/insn.c '-I "^#include [\"<]\(../include/\)*asm/in\(at\|sn\).h[\">]" -I "^#include [\"<]\(../include/\)*asm/emulate_prefix.h[\">]"'

# diff non-symmetric files
check_2 tools/perf/arch/x86/entry/syscalls/syscall_64.tbl arch/x86/entry/syscalls/syscall_64.tbl