* [PATCH 1/2] powerpc/64s/exception: treat NIA below __end_interrupts as soft-masked
From: Nicholas Piggin @ 2020-06-11 8:12 UTC (permalink / raw)
To: linuxppc-dev; +Cc: libc-dev, musl, Nicholas Piggin, linux-api
In-Reply-To: <20200611081203.995112-1-npiggin@gmail.com>
The scv instruction causes an interrupt which can enter the kernel with
MSR[EE]=1, thus allowing interrupts to hit at any time. These must not
be taken as normal interrupts, because they come from MSR[PR]=0 context,
and yet the kernel stack is not yet set up and r13 is not set to the
PACA).
Treat this as a soft-masked interrupt regardless of the soft masked
state. This does not affect behaviour yet, because currently all
interrupts are taken with MSR[EE]=0.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
arch/powerpc/kernel/exceptions-64s.S | 27 ++++++++++++++++++++++++---
1 file changed, 24 insertions(+), 3 deletions(-)
diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S
index e70ebb5c318c..388e34665b4a 100644
--- a/arch/powerpc/kernel/exceptions-64s.S
+++ b/arch/powerpc/kernel/exceptions-64s.S
@@ -508,8 +508,24 @@ DEFINE_FIXED_SYMBOL(\name\()_common_real)
.macro __GEN_COMMON_BODY name
.if IMASK
+ .if ! ISTACK
+ .error "No support for masked interrupt to use custom stack"
+ .endif
+
+ /* If coming from user, skip soft-mask tests. */
+ andi. r10,r12,MSR_PR
+ bne 2f
+
+ /* Kernel code running below __end_interrupts is implicitly
+ * soft-masked */
+ LOAD_HANDLER(r10, __end_interrupts)
+ cmpld r11,r10
+ li r10,IMASK
+ blt- 1f
+
+ /* Test the soft mask state against our interrupt's bit */
lbz r10,PACAIRQSOFTMASK(r13)
- andi. r10,r10,IMASK
+1: andi. r10,r10,IMASK
/* Associate vector numbers with bits in paca->irq_happened */
.if IVEC == 0x500 || IVEC == 0xea0
li r10,PACA_IRQ_EE
@@ -540,7 +556,7 @@ DEFINE_FIXED_SYMBOL(\name\()_common_real)
.if ISTACK
andi. r10,r12,MSR_PR /* See if coming from user */
- mr r10,r1 /* Save r1 */
+2: mr r10,r1 /* Save r1 */
subi r1,r1,INT_FRAME_SIZE /* alloc frame on kernel stack */
beq- 100f
ld r1,PACAKSAVE(r13) /* kernel stack to use */
@@ -2838,7 +2854,8 @@ masked_interrupt:
ld r10,PACA_EXGEN+EX_R10(r13)
ld r11,PACA_EXGEN+EX_R11(r13)
ld r12,PACA_EXGEN+EX_R12(r13)
- /* returns to kernel where r13 must be set up, so don't restore it */
+ ld r13,PACA_EXGEN+EX_R13(r13)
+ /* May return to masked low address where r13 is not set up */
.if \hsrr
HRFI_TO_KERNEL
.else
@@ -2997,6 +3014,10 @@ EXC_COMMON_BEGIN(ppc64_runlatch_on_trampoline)
USE_FIXED_SECTION(virt_trampolines)
/*
+ * All code below __end_interrupts is treated as soft-masked. If
+ * any code runs here with MSR[EE]=1, it must then cope with pending
+ * soft interrupt being raised (i.e., by ensuring it is replayed).
+ *
* The __end_interrupts marker must be past the out-of-line (OOL)
* handlers, so that they are copied to real address 0x100 when running
* a relocatable kernel. This ensures they can be reached from the short
--
2.23.0
^ permalink raw reply related
* [PATCH 2/2] powerpc/64s: system call support for scv/rfscv instructions
From: Nicholas Piggin @ 2020-06-11 8:12 UTC (permalink / raw)
To: linuxppc-dev; +Cc: libc-dev, musl, Nicholas Piggin, linux-api
In-Reply-To: <20200611081203.995112-1-npiggin@gmail.com>
Add support for the scv instruction on POWER9 and later CPUs.
For now this implements the zeroth scv vector 'scv 0', as identical to
'sc' system calls, with the exception that lr is not preserved, nor are
volatile cr registers, and error is not indicated with CR0[SO], but by
returning a negative errno.
rfscv is implemented to return from scv type system calls. It can not be
used to return from sc system calls because those are defined to
preserve lr.
getpid syscall throughput on POWER9 is improved by 26% (428 to 318
cycles), largely due to reducing mtmsr and mtspr.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
Documentation/powerpc/syscall64-abi.rst | 42 ++++--
arch/powerpc/include/asm/asm-prototypes.h | 2 +-
arch/powerpc/include/asm/exception-64s.h | 6 +
arch/powerpc/include/asm/head-64.h | 2 +-
arch/powerpc/include/asm/ppc-opcode.h | 2 +
arch/powerpc/include/asm/ppc_asm.h | 2 +
arch/powerpc/include/asm/ptrace.h | 7 +-
arch/powerpc/include/asm/setup.h | 4 +-
arch/powerpc/include/asm/sstep.h | 1 +
arch/powerpc/kernel/cpu_setup_power.S | 10 +-
arch/powerpc/kernel/cputable.c | 3 +-
arch/powerpc/kernel/dt_cpu_ftrs.c | 1 +
arch/powerpc/kernel/entry_64.S | 171 +++++++++++++++++++++-
arch/powerpc/kernel/exceptions-64s.S | 123 +++++++++++++++-
arch/powerpc/kernel/process.c | 10 +-
arch/powerpc/kernel/setup_64.c | 5 +-
arch/powerpc/kernel/signal.c | 19 ++-
arch/powerpc/kernel/syscall_64.c | 32 +++-
arch/powerpc/lib/sstep.c | 14 ++
arch/powerpc/platforms/pseries/setup.c | 8 +-
arch/powerpc/xmon/xmon.c | 1 +
21 files changed, 421 insertions(+), 44 deletions(-)
diff --git a/Documentation/powerpc/syscall64-abi.rst b/Documentation/powerpc/syscall64-abi.rst
index e49f69f941b9..46caaadbb029 100644
--- a/Documentation/powerpc/syscall64-abi.rst
+++ b/Documentation/powerpc/syscall64-abi.rst
@@ -5,6 +5,15 @@ Power Architecture 64-bit Linux system call ABI
syscall
=======
+Invocation
+----------
+The syscall is made with the sc instruction, and returns with execution
+continuing at the instruction following the sc instruction.
+
+If PPC_FEATURE2_SCV appears in the AT_HWCAP2 ELF auxiliary vector, the
+scv 0 instruction is an alternative that may provide better performance,
+with some differences to calling sequence.
+
syscall calling sequence\ [1]_ matches the Power Architecture 64-bit ELF ABI
specification C function calling sequence, including register preservation
rules, with the following differences.
@@ -12,16 +21,23 @@ rules, with the following differences.
.. [1] Some syscalls (typically low-level management functions) may have
different calling sequences (e.g., rt_sigreturn).
-Parameters and return value
----------------------------
+Parameters
+----------
The system call number is specified in r0.
There is a maximum of 6 integer parameters to a syscall, passed in r3-r8.
-Both a return value and a return error code are returned. cr0.SO is the return
-error code, and r3 is the return value or error code. When cr0.SO is clear,
-the syscall succeeded and r3 is the return value. When cr0.SO is set, the
-syscall failed and r3 is the error code that generally corresponds to errno.
+Return value
+------------
+- For the sc instruction, both a value and an error condition are returned.
+ cr0.SO is the error condition, and r3 is the return value. When cr0.SO is
+ clear, the syscall succeeded and r3 is the return value. When cr0.SO is set,
+ the syscall failed and r3 is the error value (that normally corresponds to
+ errno).
+
+- For the scv 0 instruction, the return value indicates failure if it is
+ -4095..-1 (i.e., it is >= -MAX_ERRNO (-4095) as an unsigned comparison),
+ in which case the error value is the negated return value.
Stack
-----
@@ -34,22 +50,23 @@ Register preservation rules match the ELF ABI calling sequence with the
following differences:
=========== ============= ========================================
+--- For the sc instruction, differences with the ELF ABI ---
r0 Volatile (System call number.)
r3 Volatile (Parameter 1, and return value.)
r4-r8 Volatile (Parameters 2-6.)
-cr0 Volatile (cr0.SO is the return error condition)
+cr0 Volatile (cr0.SO is the return error condition.)
cr1, cr5-7 Nonvolatile
lr Nonvolatile
+
+--- For the scv 0 instruction, differences with the ELF ABI ---
+r0 Volatile (System call number.)
+r3 Volatile (Parameter 1, and return value.)
+r4-r8 Volatile (Parameters 2-6.)
=========== ============= ========================================
All floating point and vector data registers as well as control and status
registers are nonvolatile.
-Invocation
-----------
-The syscall is performed with the sc instruction, and returns with execution
-continuing at the instruction following the sc instruction.
-
Transactional Memory
--------------------
Syscall behavior can change if the processor is in transactional or suspended
@@ -75,6 +92,7 @@ auxiliary vector.
returning to the caller. This case is not well defined or supported, so this
behavior should not be relied upon.
+scv 0 syscalls will always behave as PPC_FEATURE2_HTM_NOSC.
vsyscall
========
diff --git a/arch/powerpc/include/asm/asm-prototypes.h b/arch/powerpc/include/asm/asm-prototypes.h
index 7d81e86a1e5d..fb47bf5818c8 100644
--- a/arch/powerpc/include/asm/asm-prototypes.h
+++ b/arch/powerpc/include/asm/asm-prototypes.h
@@ -98,7 +98,7 @@ unsigned long __init early_init(unsigned long dt_ptr);
void __init machine_init(u64 dt_ptr);
#endif
long system_call_exception(long r3, long r4, long r5, long r6, long r7, long r8, unsigned long r0, struct pt_regs *regs);
-notrace unsigned long syscall_exit_prepare(unsigned long r3, struct pt_regs *regs);
+notrace unsigned long syscall_exit_prepare(unsigned long r3, struct pt_regs *regs, long scv);
notrace unsigned long interrupt_exit_user_prepare(struct pt_regs *regs, unsigned long msr);
notrace unsigned long interrupt_exit_kernel_prepare(struct pt_regs *regs, unsigned long msr);
diff --git a/arch/powerpc/include/asm/exception-64s.h b/arch/powerpc/include/asm/exception-64s.h
index 47bd4ea0837d..0c2fe7f042d1 100644
--- a/arch/powerpc/include/asm/exception-64s.h
+++ b/arch/powerpc/include/asm/exception-64s.h
@@ -123,6 +123,12 @@
hrfid; \
b hrfi_flush_fallback
+#define RFSCV_TO_USER \
+ STF_EXIT_BARRIER_SLOT; \
+ RFI_FLUSH_SLOT; \
+ RFSCV; \
+ b rfscv_flush_fallback
+
#endif /* __ASSEMBLY__ */
#endif /* _ASM_POWERPC_EXCEPTION_H */
diff --git a/arch/powerpc/include/asm/head-64.h b/arch/powerpc/include/asm/head-64.h
index 2dabcf668292..4cb9efa2eb21 100644
--- a/arch/powerpc/include/asm/head-64.h
+++ b/arch/powerpc/include/asm/head-64.h
@@ -128,7 +128,7 @@ end_##sname:
.if ((start) % (size) != 0); \
.error "Fixed section exception vector misalignment"; \
.endif; \
- .if ((size) != 0x20) && ((size) != 0x80) && ((size) != 0x100); \
+ .if ((size) != 0x20) && ((size) != 0x80) && ((size) != 0x100) && ((size) != 0x1000); \
.error "Fixed section exception vector bad size"; \
.endif; \
.if (start) < sname##_start; \
diff --git a/arch/powerpc/include/asm/ppc-opcode.h b/arch/powerpc/include/asm/ppc-opcode.h
index 2a39c716c343..b2bdc4de1292 100644
--- a/arch/powerpc/include/asm/ppc-opcode.h
+++ b/arch/powerpc/include/asm/ppc-opcode.h
@@ -257,6 +257,7 @@
#define PPC_INST_MFVSRD 0x7c000066
#define PPC_INST_MTVSRD 0x7c000166
#define PPC_INST_SC 0x44000002
+#define PPC_INST_SCV 0x44000001
#define PPC_INST_SLBFEE 0x7c0007a7
#define PPC_INST_SLBIA 0x7c0003e4
@@ -411,6 +412,7 @@
#define __PPC_CT(t) (((t) & 0x0f) << 21)
#define __PPC_SPR(r) ((((r) & 0x1f) << 16) | ((((r) >> 5) & 0x1f) << 11))
#define __PPC_RC21 (0x1 << 10)
+#define __PPC_LEV(l) (((l) & 0x7f) << 5)
/*
* Both low and high 16 bits are added as SIGNED additions, so if low 16 bits
diff --git a/arch/powerpc/include/asm/ppc_asm.h b/arch/powerpc/include/asm/ppc_asm.h
index 6b03dff61a05..160f3bb77ea4 100644
--- a/arch/powerpc/include/asm/ppc_asm.h
+++ b/arch/powerpc/include/asm/ppc_asm.h
@@ -755,6 +755,8 @@ END_FTR_SECTION_NESTED(CPU_FTR_CELL_TB_BUG, CPU_FTR_CELL_TB_BUG, 96)
#define N_SLINE 68
#define N_SO 100
+#define RFSCV .long 0x4c0000a4
+
/*
* Create an endian fixup trampoline
*
diff --git a/arch/powerpc/include/asm/ptrace.h b/arch/powerpc/include/asm/ptrace.h
index ac3970fff0d5..f194339cef3b 100644
--- a/arch/powerpc/include/asm/ptrace.h
+++ b/arch/powerpc/include/asm/ptrace.h
@@ -222,9 +222,14 @@ static inline void set_trap(struct pt_regs *regs, unsigned long val)
regs->trap = (regs->trap & TRAP_FLAGS_MASK) | (val & ~TRAP_FLAGS_MASK);
}
+static inline bool trap_is_scv(struct pt_regs *regs)
+{
+ return (IS_ENABLED(CONFIG_PPC_BOOK3S_64) && TRAP(regs) == 0x3000);
+}
+
static inline bool trap_is_syscall(struct pt_regs *regs)
{
- return TRAP(regs) == 0xc00;
+ return (trap_is_scv(regs) || TRAP(regs) == 0xc00);
}
static inline bool trap_norestart(struct pt_regs *regs)
diff --git a/arch/powerpc/include/asm/setup.h b/arch/powerpc/include/asm/setup.h
index 65676e2325b8..9efbddee2bca 100644
--- a/arch/powerpc/include/asm/setup.h
+++ b/arch/powerpc/include/asm/setup.h
@@ -30,12 +30,12 @@ void setup_panic(void);
#define ARCH_PANIC_TIMEOUT 180
#ifdef CONFIG_PPC_PSERIES
-extern void pseries_enable_reloc_on_exc(void);
+extern bool pseries_enable_reloc_on_exc(void);
extern void pseries_disable_reloc_on_exc(void);
extern void pseries_big_endian_exceptions(void);
extern void pseries_little_endian_exceptions(void);
#else
-static inline void pseries_enable_reloc_on_exc(void) {}
+static inline bool pseries_enable_reloc_on_exc(void) { return false; }
static inline void pseries_disable_reloc_on_exc(void) {}
static inline void pseries_big_endian_exceptions(void) {}
static inline void pseries_little_endian_exceptions(void) {}
diff --git a/arch/powerpc/include/asm/sstep.h b/arch/powerpc/include/asm/sstep.h
index 3b01c69a44aa..eaa4fb6c8960 100644
--- a/arch/powerpc/include/asm/sstep.h
+++ b/arch/powerpc/include/asm/sstep.h
@@ -40,6 +40,7 @@ enum instruction_type {
CACHEOP,
BARRIER,
SYSCALL,
+ SYSCALL_VECTORED_0,
MFMSR,
MTMSR,
RFI,
diff --git a/arch/powerpc/kernel/cpu_setup_power.S b/arch/powerpc/kernel/cpu_setup_power.S
index efdcfa714106..86527d19348c 100644
--- a/arch/powerpc/kernel/cpu_setup_power.S
+++ b/arch/powerpc/kernel/cpu_setup_power.S
@@ -98,7 +98,7 @@ _GLOBAL(__setup_cpu_power10)
_GLOBAL(__setup_cpu_power9)
mflr r11
- bl __init_FSCR
+ bl __init_FSCR_power9
1: bl __init_PMU
bl __init_hvmode_206
mtlr r11
@@ -128,7 +128,7 @@ _GLOBAL(__restore_cpu_power10)
_GLOBAL(__restore_cpu_power9)
mflr r11
- bl __init_FSCR
+ bl __init_FSCR_power9
1: bl __init_PMU
mfmsr r3
rldicl. r0,r3,4,63
@@ -198,6 +198,12 @@ __init_FSCR_power10:
mtspr SPRN_FSCR, r3
// fall through
+__init_FSCR_power9:
+ mfspr r3, SPRN_FSCR
+ ori r3, r3, FSCR_SCV
+ mtspr SPRN_FSCR, r3
+ // fall through
+
__init_FSCR:
mfspr r3,SPRN_FSCR
ori r3,r3,FSCR_TAR|FSCR_EBB
diff --git a/arch/powerpc/kernel/cputable.c b/arch/powerpc/kernel/cputable.c
index b4066354f073..3d406a9626e8 100644
--- a/arch/powerpc/kernel/cputable.c
+++ b/arch/powerpc/kernel/cputable.c
@@ -120,7 +120,8 @@ extern void __restore_cpu_e6500(void);
#define COMMON_USER2_POWER9 (COMMON_USER2_POWER8 | \
PPC_FEATURE2_ARCH_3_00 | \
PPC_FEATURE2_HAS_IEEE128 | \
- PPC_FEATURE2_DARN )
+ PPC_FEATURE2_DARN | \
+ PPC_FEATURE2_SCV)
#define COMMON_USER_POWER10 COMMON_USER_POWER9
#define COMMON_USER2_POWER10 (COMMON_USER2_POWER9 | \
PPC_FEATURE2_ARCH_3_1 | \
diff --git a/arch/powerpc/kernel/dt_cpu_ftrs.c b/arch/powerpc/kernel/dt_cpu_ftrs.c
index 3a409517c031..50b2d544361e 100644
--- a/arch/powerpc/kernel/dt_cpu_ftrs.c
+++ b/arch/powerpc/kernel/dt_cpu_ftrs.c
@@ -587,6 +587,7 @@ static struct dt_cpu_feature_match __initdata
{"little-endian", feat_enable_le, CPU_FTR_REAL_LE},
{"smt", feat_enable_smt, 0},
{"interrupt-facilities", feat_enable, 0},
+ {"system-call-vectored", feat_enable, 0},
{"timer-facilities", feat_enable, 0},
{"timer-facilities-v3", feat_enable, 0},
{"debug-facilities", feat_enable, 0},
diff --git a/arch/powerpc/kernel/entry_64.S b/arch/powerpc/kernel/entry_64.S
index 9d49338e0c85..223c4f008e63 100644
--- a/arch/powerpc/kernel/entry_64.S
+++ b/arch/powerpc/kernel/entry_64.S
@@ -64,15 +64,173 @@ exception_marker:
.section ".text"
.align 7
+#ifdef CONFIG_PPC_BOOK3S
+.macro system_call_vectored name trapnr
+ .globl system_call_vectored_\name
+system_call_vectored_\name:
+_ASM_NOKPROBE_SYMBOL(system_call_vectored_\name)
+#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
+BEGIN_FTR_SECTION
+ extrdi. r10, r12, 1, (63-MSR_TS_T_LG) /* transaction active? */
+ bne .Ltabort_syscall
+END_FTR_SECTION_IFSET(CPU_FTR_TM)
+#endif
+ INTERRUPT_TO_KERNEL
+ mr r10,r1
+ ld r1,PACAKSAVE(r13)
+ std r10,0(r1)
+ std r11,_NIP(r1)
+ std r12,_MSR(r1)
+ std r0,GPR0(r1)
+ std r10,GPR1(r1)
+ std r2,GPR2(r1)
+ ld r2,PACATOC(r13)
+ mfcr r12
+ li r11,0
+ /* Can we avoid saving r3-r8 in common case? */
+ std r3,GPR3(r1)
+ std r4,GPR4(r1)
+ std r5,GPR5(r1)
+ std r6,GPR6(r1)
+ std r7,GPR7(r1)
+ std r8,GPR8(r1)
+ /* Zero r9-r12, this should only be required when restoring all GPRs */
+ std r11,GPR9(r1)
+ std r11,GPR10(r1)
+ std r11,GPR11(r1)
+ std r11,GPR12(r1)
+ std r9,GPR13(r1)
+ SAVE_NVGPRS(r1)
+ std r11,_XER(r1)
+ std r11,_LINK(r1)
+ std r11,_CTR(r1)
+
+ li r11,\trapnr
+ std r11,_TRAP(r1)
+ std r12,_CCR(r1)
+ std r3,ORIG_GPR3(r1)
+ addi r10,r1,STACK_FRAME_OVERHEAD
+ ld r11,exception_marker@toc(r2)
+ std r11,-16(r10) /* "regshere" marker */
+
+ /*
+ * RECONCILE_IRQ_STATE without calling trace_hardirqs_off(), which
+ * would clobber syscall parameters. Also we always enter with IRQs
+ * enabled and nothing pending. system_call_exception() will call
+ * trace_hardirqs_off().
+ *
+ * scv enters with MSR[EE]=1, so don't set PACA_IRQ_HARD_DIS. The
+ * entry vector already sets PACAIRQSOFTMASK to IRQS_ALL_DISABLED.
+ */
+
+ /* Calling convention has r9 = orig r0, r10 = regs */
+ mr r9,r0
+ bl system_call_exception
+
+.Lsyscall_vectored_\name\()_exit:
+ addi r4,r1,STACK_FRAME_OVERHEAD
+ li r5,1 /* scv */
+ bl syscall_exit_prepare
+
+ ld r2,_CCR(r1)
+ ld r4,_NIP(r1)
+ ld r5,_MSR(r1)
+
+BEGIN_FTR_SECTION
+ stdcx. r0,0,r1 /* to clear the reservation */
+END_FTR_SECTION_IFCLR(CPU_FTR_STCX_CHECKS_ADDRESS)
+
+BEGIN_FTR_SECTION
+ HMT_MEDIUM_LOW
+END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR)
+
+ cmpdi r3,0
+ bne .Lsyscall_vectored_\name\()_restore_regs
+
+ /* rfscv returns with LR->NIA and CTR->MSR */
+ mtlr r4
+ mtctr r5
+
+ /* Could zero these as per ABI, but we may consider a stricter ABI
+ * which preserves these if libc implementations can benefit, so
+ * restore them for now until further measurement is done. */
+ ld r0,GPR0(r1)
+ ld r4,GPR4(r1)
+ ld r5,GPR5(r1)
+ ld r6,GPR6(r1)
+ ld r7,GPR7(r1)
+ ld r8,GPR8(r1)
+ /* Zero volatile regs that may contain sensitive kernel data */
+ li r9,0
+ li r10,0
+ li r11,0
+ li r12,0
+ mtspr SPRN_XER,r0
+
+ /*
+ * We don't need to restore AMR on the way back to userspace for KUAP.
+ * The value of AMR only matters while we're in the kernel.
+ */
+ mtcr r2
+ ld r2,GPR2(r1)
+ ld r3,GPR3(r1)
+ ld r13,GPR13(r1)
+ ld r1,GPR1(r1)
+ RFSCV_TO_USER
+ b . /* prevent speculative execution */
+
+.Lsyscall_vectored_\name\()_restore_regs:
+ li r3,0
+ mtmsrd r3,1
+ mtspr SPRN_SRR0,r4
+ mtspr SPRN_SRR1,r5
+
+ ld r3,_CTR(r1)
+ ld r4,_LINK(r1)
+ ld r5,_XER(r1)
+
+ REST_NVGPRS(r1)
+ ld r0,GPR0(r1)
+ mtcr r2
+ mtctr r3
+ mtlr r4
+ mtspr SPRN_XER,r5
+ REST_10GPRS(2, r1)
+ REST_2GPRS(12, r1)
+ ld r1,GPR1(r1)
+ RFI_TO_USER
+.endm
+
+system_call_vectored common 0x3000
+/*
+ * We instantiate another entry copy for the SIGILL variant, with TRAP=0x7ff0
+ * which is tested by system_call_exception when r0 is -1 (as set by vector
+ * entry code).
+ */
+system_call_vectored sigill 0x7ff0
+
+
+/*
+ * Entered via kernel return set up by kernel/sstep.c, must match entry regs
+ */
+ .globl system_call_vectored_emulate
+system_call_vectored_emulate:
+_ASM_NOKPROBE_SYMBOL(system_call_vectored_emulate)
+ li r10,IRQS_ALL_DISABLED
+ stb r10,PACAIRQSOFTMASK(r13)
+ b system_call_vectored_common
+#endif
+
+ .balign IFETCH_ALIGN_BYTES
.globl system_call_common
system_call_common:
+_ASM_NOKPROBE_SYMBOL(system_call_common)
#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
BEGIN_FTR_SECTION
extrdi. r10, r12, 1, (63-MSR_TS_T_LG) /* transaction active? */
bne .Ltabort_syscall
END_FTR_SECTION_IFSET(CPU_FTR_TM)
#endif
-_ASM_NOKPROBE_SYMBOL(system_call_common)
mr r10,r1
ld r1,PACAKSAVE(r13)
std r10,0(r1)
@@ -138,6 +296,7 @@ END_BTB_FLUSH_SECTION
.Lsyscall_exit:
addi r4,r1,STACK_FRAME_OVERHEAD
+ li r5,0 /* !scv */
bl syscall_exit_prepare
ld r2,_CCR(r1)
@@ -224,10 +383,18 @@ END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR)
b . /* prevent speculative execution */
#endif
+#ifdef CONFIG_PPC_BOOK3S
+_GLOBAL(ret_from_fork_scv)
+ bl schedule_tail
+ REST_NVGPRS(r1)
+ li r3,0 /* fork() return value */
+ b .Lsyscall_vectored_common_exit
+#endif
+
_GLOBAL(ret_from_fork)
bl schedule_tail
REST_NVGPRS(r1)
- li r3,0
+ li r3,0 /* fork() return value */
b .Lsyscall_exit
_GLOBAL(ret_from_kernel_thread)
diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S
index 388e34665b4a..f5f24e6c685f 100644
--- a/arch/powerpc/kernel/exceptions-64s.S
+++ b/arch/powerpc/kernel/exceptions-64s.S
@@ -756,6 +756,9 @@ END_FTR_SECTION_IFSET(CPU_FTR_CAN_NAP)
* guarantee they will be delivered virtually. Some conditions (see the ISA)
* cause exceptions to be delivered in real mode.
*
+ * The scv instructions are a special case. They get a 0x3000 offset applied.
+ * scv exceptions have unique reentrancy properties, see below.
+ *
* It's impossible to receive interrupts below 0x300 via AIL.
*
* KVM: None of the virtual exceptions are from the guest. Anything that
@@ -765,8 +768,8 @@ END_FTR_SECTION_IFSET(CPU_FTR_CAN_NAP)
* We layout physical memory as follows:
* 0x0000 - 0x00ff : Secondary processor spin code
* 0x0100 - 0x18ff : Real mode pSeries interrupt vectors
- * 0x1900 - 0x3fff : Real mode trampolines
- * 0x4000 - 0x58ff : Relon (IR=1,DR=1) mode pSeries interrupt vectors
+ * 0x1900 - 0x2fff : Real mode trampolines
+ * 0x3000 - 0x58ff : Relon (IR=1,DR=1) mode pSeries interrupt vectors
* 0x5900 - 0x6fff : Relon mode trampolines
* 0x7000 - 0x7fff : FWNMI data area
* 0x8000 - .... : Common interrupt handlers, remaining early
@@ -777,8 +780,8 @@ END_FTR_SECTION_IFSET(CPU_FTR_CAN_NAP)
* vectors there.
*/
OPEN_FIXED_SECTION(real_vectors, 0x0100, 0x1900)
-OPEN_FIXED_SECTION(real_trampolines, 0x1900, 0x4000)
-OPEN_FIXED_SECTION(virt_vectors, 0x4000, 0x5900)
+OPEN_FIXED_SECTION(real_trampolines, 0x1900, 0x3000)
+OPEN_FIXED_SECTION(virt_vectors, 0x3000, 0x5900)
OPEN_FIXED_SECTION(virt_trampolines, 0x5900, 0x7000)
#ifdef CONFIG_PPC_POWERNV
@@ -814,6 +817,77 @@ USE_FIXED_SECTION(real_vectors)
.globl __start_interrupts
__start_interrupts:
+/**
+ * Interrupt 0x3000 - System Call Vectored Interrupt (syscall).
+ * This is a synchronous interrupt invoked with the "scv" instruction. The
+ * system call does not alter the HV bit, so it is directed to the OS.
+ *
+ * Handling:
+ * scv instructions enter the kernel without changing EE, RI, ME, or HV.
+ * In particular, this means we can take a maskable interrupt at any point
+ * in the scv handler, which is unlike any other interrupt. This is solved
+ * by treating the instruction addresses below __end_interrupts as being
+ * soft-masked.
+ *
+ * AIL-0 mode scv exceptions go to 0x17000-0x17fff, but we set AIL-3 and
+ * ensure scv is never executed with relocation off, which means AIL-0
+ * should never happen.
+ *
+ * Before leaving the below __end_interrupts text, at least of the following
+ * must be true:
+ * - MSR[PR]=1 (i.e., return to userspace)
+ * - MSR_EE|MSR_RI is set (no reentrant exceptions)
+ * - Standard kernel environment is set up (stack, paca, etc)
+ *
+ * Call convention:
+ *
+ * syscall register convention is in Documentation/powerpc/syscall64-abi.rst
+ */
+EXC_VIRT_BEGIN(system_call_vectored, 0x3000, 0x1000)
+ /* SCV 0 */
+ mr r9,r13
+ GET_PACA(r13)
+ mflr r11
+ mfctr r12
+ li r10,IRQS_ALL_DISABLED
+ stb r10,PACAIRQSOFTMASK(r13)
+#ifdef CONFIG_RELOCATABLE
+ b system_call_vectored_tramp
+#else
+ b system_call_vectored_common
+#endif
+ nop
+
+ /* SCV 1 - 127 */
+ .rept 127
+ mr r9,r13
+ GET_PACA(r13)
+ mflr r11
+ mfctr r12
+ li r10,IRQS_ALL_DISABLED
+ stb r10,PACAIRQSOFTMASK(r13)
+ li r0,-1 /* cause failure */
+#ifdef CONFIG_RELOCATABLE
+ b system_call_vectored_sigill_tramp
+#else
+ b system_call_vectored_sigill
+#endif
+ .endr
+EXC_VIRT_END(system_call_vectored, 0x3000, 0x1000)
+
+#ifdef CONFIG_RELOCATABLE
+TRAMP_VIRT_BEGIN(system_call_vectored_tramp)
+ __LOAD_HANDLER(r10, system_call_vectored_common)
+ mtctr r10
+ bctr
+
+TRAMP_VIRT_BEGIN(system_call_vectored_sigill_tramp)
+ __LOAD_HANDLER(r10, system_call_vectored_sigill)
+ mtctr r10
+ bctr
+#endif
+
+
/* No virt vectors corresponding with 0x0..0x100 */
EXC_VIRT_NONE(0x4000, 0x100)
@@ -2963,6 +3037,47 @@ TRAMP_REAL_BEGIN(hrfi_flush_fallback)
GET_SCRATCH0(r13);
hrfid
+TRAMP_REAL_BEGIN(rfscv_flush_fallback)
+ /* system call volatile */
+ mr r7,r13
+ GET_PACA(r13);
+ mr r8,r1
+ ld r1,PACAKSAVE(r13)
+ mfctr r9
+ ld r10,PACA_RFI_FLUSH_FALLBACK_AREA(r13)
+ ld r11,PACA_L1D_FLUSH_SIZE(r13)
+ srdi r11,r11,(7 + 3) /* 128 byte lines, unrolled 8x */
+ mtctr r11
+ DCBT_BOOK3S_STOP_ALL_STREAM_IDS(r11) /* Stop prefetch streams */
+
+ /* order ld/st prior to dcbt stop all streams with flushing */
+ sync
+
+ /*
+ * The load adresses are at staggered offsets within cachelines,
+ * which suits some pipelines better (on others it should not
+ * hurt).
+ */
+1:
+ ld r11,(0x80 + 8)*0(r10)
+ ld r11,(0x80 + 8)*1(r10)
+ ld r11,(0x80 + 8)*2(r10)
+ ld r11,(0x80 + 8)*3(r10)
+ ld r11,(0x80 + 8)*4(r10)
+ ld r11,(0x80 + 8)*5(r10)
+ ld r11,(0x80 + 8)*6(r10)
+ ld r11,(0x80 + 8)*7(r10)
+ addi r10,r10,0x80*8
+ bdnz 1b
+
+ mtctr r9
+ li r9,0
+ li r10,0
+ li r11,0
+ mr r1,r8
+ mr r13,r7
+ RFSCV
+
USE_TEXT_SECTION()
MASKED_INTERRUPT
MASKED_INTERRUPT hsrr=1
diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c
index 7bb7faf84490..a0c2746f8c11 100644
--- a/arch/powerpc/kernel/process.c
+++ b/arch/powerpc/kernel/process.c
@@ -1596,6 +1596,7 @@ int copy_thread_tls(unsigned long clone_flags, unsigned long usp,
{
struct pt_regs *childregs, *kregs;
extern void ret_from_fork(void);
+ extern void ret_from_fork_scv(void);
extern void ret_from_kernel_thread(void);
void (*f)(void);
unsigned long sp = (unsigned long)task_stack_page(p) + THREAD_SIZE;
@@ -1632,7 +1633,9 @@ int copy_thread_tls(unsigned long clone_flags, unsigned long usp,
if (usp)
childregs->gpr[1] = usp;
p->thread.regs = childregs;
- childregs->gpr[3] = 0; /* Result from fork() */
+ /* 64s sets this in ret_from_fork */
+ if (!IS_ENABLED(CONFIG_PPC_BOOK3S_64))
+ childregs->gpr[3] = 0; /* Result from fork() */
if (clone_flags & CLONE_SETTLS) {
if (!is_32bit_task())
childregs->gpr[13] = tls;
@@ -1640,7 +1643,10 @@ int copy_thread_tls(unsigned long clone_flags, unsigned long usp,
childregs->gpr[2] = tls;
}
- f = ret_from_fork;
+ if (trap_is_scv(regs))
+ f = ret_from_fork_scv;
+ else
+ f = ret_from_fork;
}
childregs->msr &= ~(MSR_FP|MSR_VEC|MSR_VSX);
sp -= STACK_FRAME_OVERHEAD;
diff --git a/arch/powerpc/kernel/setup_64.c b/arch/powerpc/kernel/setup_64.c
index 0ba1ed77dc68..6be430107c6f 100644
--- a/arch/powerpc/kernel/setup_64.c
+++ b/arch/powerpc/kernel/setup_64.c
@@ -196,7 +196,10 @@ static void __init configure_exceptions(void)
/* Under a PAPR hypervisor, we need hypercalls */
if (firmware_has_feature(FW_FEATURE_SET_MODE)) {
/* Enable AIL if possible */
- pseries_enable_reloc_on_exc();
+ if (!pseries_enable_reloc_on_exc()) {
+ init_task.thread.fscr &= ~FSCR_SCV;
+ cur_cpu_spec->cpu_user_features2 &= ~PPC_FEATURE2_SCV;
+ }
/*
* Tell the hypervisor that we want our exceptions to
diff --git a/arch/powerpc/kernel/signal.c b/arch/powerpc/kernel/signal.c
index b4143b6ff093..d15a98c758b8 100644
--- a/arch/powerpc/kernel/signal.c
+++ b/arch/powerpc/kernel/signal.c
@@ -205,8 +205,14 @@ static void check_syscall_restart(struct pt_regs *regs, struct k_sigaction *ka,
return;
/* error signalled ? */
- if (!(regs->ccr & 0x10000000))
+ if (trap_is_scv(regs)) {
+ /* 32-bit compat mode sign extend? */
+ if (!IS_ERR_VALUE(ret))
+ return;
+ ret = -ret;
+ } else if (!(regs->ccr & 0x10000000)) {
return;
+ }
switch (ret) {
case ERESTART_RESTARTBLOCK:
@@ -239,9 +245,14 @@ static void check_syscall_restart(struct pt_regs *regs, struct k_sigaction *ka,
regs->nip -= 4;
regs->result = 0;
} else {
- regs->result = -EINTR;
- regs->gpr[3] = EINTR;
- regs->ccr |= 0x10000000;
+ if (trap_is_scv(regs)) {
+ regs->result = -EINTR;
+ regs->gpr[3] = -EINTR;
+ } else {
+ regs->result = -EINTR;
+ regs->gpr[3] = EINTR;
+ regs->ccr |= 0x10000000;
+ }
}
}
diff --git a/arch/powerpc/kernel/syscall_64.c b/arch/powerpc/kernel/syscall_64.c
index 79edba3ab312..a783fd324cb0 100644
--- a/arch/powerpc/kernel/syscall_64.c
+++ b/arch/powerpc/kernel/syscall_64.c
@@ -60,6 +60,11 @@ notrace long system_call_exception(long r3, long r4, long r5,
local_irq_enable();
if (unlikely(current_thread_info()->flags & _TIF_SYSCALL_DOTRACE)) {
+ if (unlikely(regs->trap == 0x7ff0)) {
+ /* Unsupported scv vector */
+ _exception(SIGILL, regs, ILL_ILLOPC, regs->nip);
+ return regs->gpr[3];
+ }
/*
* We use the return value of do_syscall_trace_enter() as the
* syscall number. If the syscall was rejected for any reason
@@ -78,6 +83,11 @@ notrace long system_call_exception(long r3, long r4, long r5,
r8 = regs->gpr[8];
} else if (unlikely(r0 >= NR_syscalls)) {
+ if (unlikely(regs->trap == 0x7ff0)) {
+ /* Unsupported scv vector */
+ _exception(SIGILL, regs, ILL_ILLOPC, regs->nip);
+ return regs->gpr[3];
+ }
return -ENOSYS;
}
@@ -105,16 +115,20 @@ notrace long system_call_exception(long r3, long r4, long r5,
* local irqs must be disabled. Returns false if the caller must re-enable
* them, check for new work, and try again.
*/
-static notrace inline bool prep_irq_for_enabled_exit(void)
+static notrace inline bool prep_irq_for_enabled_exit(bool clear_ri)
{
/* This must be done with RI=1 because tracing may touch vmaps */
trace_hardirqs_on();
/* This pattern matches prep_irq_for_idle */
- __hard_EE_RI_disable();
+ if (clear_ri)
+ __hard_EE_RI_disable();
+ else
+ __hard_irq_disable();
if (unlikely(lazy_irq_pending_nocheck())) {
/* Took an interrupt, may have more exit work to do. */
- __hard_RI_enable();
+ if (clear_ri)
+ __hard_RI_enable();
trace_hardirqs_off();
local_paca->irq_happened |= PACA_IRQ_HARD_DIS;
@@ -136,7 +150,8 @@ static notrace inline bool prep_irq_for_enabled_exit(void)
* because RI=0 and soft mask state is "unreconciled", so it is marked notrace.
*/
notrace unsigned long syscall_exit_prepare(unsigned long r3,
- struct pt_regs *regs)
+ struct pt_regs *regs,
+ long scv)
{
unsigned long *ti_flagsp = ¤t_thread_info()->flags;
unsigned long ti_flags;
@@ -151,7 +166,7 @@ notrace unsigned long syscall_exit_prepare(unsigned long r3,
ti_flags = *ti_flagsp;
- if (unlikely(r3 >= (unsigned long)-MAX_ERRNO)) {
+ if (unlikely(r3 >= (unsigned long)-MAX_ERRNO) && !scv) {
if (likely(!(ti_flags & (_TIF_NOERROR | _TIF_RESTOREALL)))) {
r3 = -r3;
regs->ccr |= 0x10000000; /* Set SO bit in CR */
@@ -211,7 +226,8 @@ notrace unsigned long syscall_exit_prepare(unsigned long r3,
}
}
- if (unlikely(!prep_irq_for_enabled_exit())) {
+ /* scv need not set RI=0 because SRRs are not used */
+ if (unlikely(!prep_irq_for_enabled_exit(!scv))) {
local_irq_enable();
goto again;
}
@@ -282,7 +298,7 @@ notrace unsigned long interrupt_exit_user_prepare(struct pt_regs *regs, unsigned
}
}
- if (unlikely(!prep_irq_for_enabled_exit())) {
+ if (unlikely(!prep_irq_for_enabled_exit(true))) {
local_irq_enable();
local_irq_disable();
goto again;
@@ -345,7 +361,7 @@ notrace unsigned long interrupt_exit_kernel_prepare(struct pt_regs *regs, unsign
}
}
- if (unlikely(!prep_irq_for_enabled_exit())) {
+ if (unlikely(!prep_irq_for_enabled_exit(true))) {
/*
* Can't local_irq_restore to replay if we were in
* interrupt context. Must replay directly.
diff --git a/arch/powerpc/lib/sstep.c b/arch/powerpc/lib/sstep.c
index 5abe98216dc2..161bfccbc309 100644
--- a/arch/powerpc/lib/sstep.c
+++ b/arch/powerpc/lib/sstep.c
@@ -16,6 +16,7 @@
#include <asm/disassemble.h>
extern char system_call_common[];
+extern char system_call_vectored_emulate[];
#ifdef CONFIG_PPC64
/* Bits in SRR1 that are copied from MSR */
@@ -1236,6 +1237,9 @@ int analyse_instr(struct instruction_op *op, const struct pt_regs *regs,
case 17: /* sc */
if ((word & 0xfe2) == 2)
op->type = SYSCALL;
+ else if (IS_ENABLED(CONFIG_PPC_BOOK3S_64) &&
+ (word & 0xfe3) == 1)
+ op->type = SYSCALL_VECTORED_0;
else
op->type = UNKNOWN;
return 0;
@@ -3378,6 +3382,16 @@ int emulate_step(struct pt_regs *regs, struct ppc_inst instr)
regs->msr = MSR_KERNEL;
return 1;
+ case SYSCALL_VECTORED_0: /* scv 0 */
+ regs->gpr[9] = regs->gpr[13];
+ regs->gpr[10] = MSR_KERNEL;
+ regs->gpr[11] = regs->nip + 4;
+ regs->gpr[12] = regs->msr & MSR_MASK;
+ regs->gpr[13] = (unsigned long) get_paca();
+ regs->nip = (unsigned long) &system_call_vectored_emulate;
+ regs->msr = MSR_KERNEL;
+ return 1;
+
case RFI:
return -1;
#endif
diff --git a/arch/powerpc/platforms/pseries/setup.c b/arch/powerpc/platforms/pseries/setup.c
index 2db8469e475f..8c85466e0dd8 100644
--- a/arch/powerpc/platforms/pseries/setup.c
+++ b/arch/powerpc/platforms/pseries/setup.c
@@ -358,7 +358,7 @@ static void pseries_lpar_idle(void)
* to ever be a problem in practice we can move this into a kernel thread to
* finish off the process later in boot.
*/
-void pseries_enable_reloc_on_exc(void)
+bool pseries_enable_reloc_on_exc(void)
{
long rc;
unsigned int delay, total_delay = 0;
@@ -369,11 +369,13 @@ void pseries_enable_reloc_on_exc(void)
if (rc == H_P2) {
pr_info("Relocation on exceptions not"
" supported\n");
+ return false;
} else if (rc != H_SUCCESS) {
pr_warn("Unable to enable relocation"
" on exceptions: %ld\n", rc);
+ return false;
}
- break;
+ return true;
}
delay = get_longbusy_msecs(rc);
@@ -382,7 +384,7 @@ void pseries_enable_reloc_on_exc(void)
pr_warn("Warning: Giving up waiting to enable "
"relocation on exceptions (%u msec)!\n",
total_delay);
- return;
+ return false;
}
mdelay(delay);
diff --git a/arch/powerpc/xmon/xmon.c b/arch/powerpc/xmon/xmon.c
index 7efe4bc3ccf6..3203c3606737 100644
--- a/arch/powerpc/xmon/xmon.c
+++ b/arch/powerpc/xmon/xmon.c
@@ -1593,6 +1593,7 @@ const char *getvecname(unsigned long vec)
case 0x1300: ret = "(Instruction Breakpoint)"; break;
case 0x1500: ret = "(Denormalisation)"; break;
case 0x1700: ret = "(Altivec Assist)"; break;
+ case 0x3000: ret = "(System Call Vectored)"; break;
default: ret = "";
}
return ret;
--
2.23.0
^ permalink raw reply related
* Re: [PATCH? v2] powerpc: Hard wire PT_SOFTE value to 1 in gpr_get() too
From: Madhavan Srinivasan @ 2020-06-11 8:52 UTC (permalink / raw)
To: Oleg Nesterov, Benjamin Herrenschmidt, Madhavan Srinivasan,
Michael Ellerman, Paul Mackerras
Cc: linuxppc-dev, Jan Kratochvil, linux-kernel
In-Reply-To: <20200610150224.GA6793@redhat.com>
On 6/10/20 8:37 PM, Oleg Nesterov wrote:
> Hi,
>
> looks like this patch was forgotten.
yep, I missed this. But mpe did have comments for the patch.
https://lkml.org/lkml/2019/9/19/107
Maddy
>
> Do you think this should be fixed or should we document that
> PTRACE_GETREGS is not consistent with PTRACE_PEEKUSER on ppc64?
>
>
> On 09/17, Oleg Nesterov wrote:
>> I don't have a ppc machine, this patch wasn't even compile tested,
>> could you please review?
>>
>> The commit a8a4b03ab95f ("powerpc: Hard wire PT_SOFTE value to 1 in
>> ptrace & signals") changed ptrace_get_reg(PT_SOFTE) to report 0x1,
>> but PTRACE_GETREGS still copies pt_regs->softe as is.
>>
>> This is not consistent and this breaks
>> http://sourceware.org/systemtap/wiki/utrace/tests/user-regs-peekpoke
>>
>> Reported-by: Jan Kratochvil <jan.kratochvil@redhat.com>
>> Signed-off-by: Oleg Nesterov <oleg@redhat.com>
>> ---
>> arch/powerpc/kernel/ptrace.c | 25 +++++++++++++++++++++++++
>> 1 file changed, 25 insertions(+)
>>
>> diff --git a/arch/powerpc/kernel/ptrace.c b/arch/powerpc/kernel/ptrace.c
>> index 8c92feb..291acfb 100644
>> --- a/arch/powerpc/kernel/ptrace.c
>> +++ b/arch/powerpc/kernel/ptrace.c
>> @@ -363,11 +363,36 @@ static int gpr_get(struct task_struct *target, const struct user_regset *regset,
>> BUILD_BUG_ON(offsetof(struct pt_regs, orig_gpr3) !=
>> offsetof(struct pt_regs, msr) + sizeof(long));
>>
>> +#ifdef CONFIG_PPC64
>> + if (!ret)
>> + ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf,
>> + &target->thread.regs->orig_gpr3,
>> + offsetof(struct pt_regs, orig_gpr3),
>> + offsetof(struct pt_regs, softe));
>> +
>> + if (!ret) {
>> + unsigned long softe = 0x1;
>> + ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, &softe,
>> + offsetof(struct pt_regs, softe),
>> + offsetof(struct pt_regs, softe) +
>> + sizeof(softe));
>> + }
>> +
>> + BUILD_BUG_ON(offsetof(struct pt_regs, trap) !=
>> + offsetof(struct pt_regs, softe) + sizeof(long));
>> +
>> + if (!ret)
>> + ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf,
>> + &target->thread.regs->trap,
>> + offsetof(struct pt_regs, trap),
>> + sizeof(struct user_pt_regs));
>> +#else
>> if (!ret)
>> ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf,
>> &target->thread.regs->orig_gpr3,
>> offsetof(struct pt_regs, orig_gpr3),
>> sizeof(struct user_pt_regs));
>> +#endif
>> if (!ret)
>> ret = user_regset_copyout_zero(&pos, &count, &kbuf, &ubuf,
>> sizeof(struct user_pt_regs), -1);
>> --
>> 2.5.0
>>
^ permalink raw reply
* Re: [PATCH? v2] powerpc: Hard wire PT_SOFTE value to 1 in gpr_get() too
From: Oleg Nesterov @ 2020-06-11 10:58 UTC (permalink / raw)
To: Madhavan Srinivasan
Cc: Madhavan Srinivasan, linuxppc-dev, linux-kernel, Paul Mackerras,
Jan Kratochvil
In-Reply-To: <321e6865-1762-c459-56c4-0cc89c7c2a7e@linux.ibm.com>
On 06/11, Madhavan Srinivasan wrote:
>
>
> On 6/10/20 8:37 PM, Oleg Nesterov wrote:
> >Hi,
> >
> >looks like this patch was forgotten.
>
> yep, I missed this. But mpe did have comments for the patch.
>
> https://lkml.org/lkml/2019/9/19/107
Yes, and I thought that I have replied... apparently not, sorry!
So let me repeat, I am fine either way, I do not understand this
ppc-specific code and I can't really test this change.
Let me quote that email from Michael:
> We could do it like below. I'm 50/50 though on whether it's worth it, or
> if we should just go with the big ifdef like in your patch.
up to you ;)
Hmm. And yes,
> >>This is not consistent and this breaks
> >>http://sourceware.org/systemtap/wiki/utrace/tests/user-regs-peekpoke
this is 404.
Jan, could correct the link above?
Oleg.
^ permalink raw reply
* Re: [PATCH? v2] powerpc: Hard wire PT_SOFTE value to 1 in gpr_get() too
From: Jan Kratochvil @ 2020-06-11 11:11 UTC (permalink / raw)
To: Oleg Nesterov
Cc: Madhavan Srinivasan, linux-kernel, Madhavan Srinivasan,
Paul Mackerras, linuxppc-dev
In-Reply-To: <20200611105830.GB12500@redhat.com>
[-- Attachment #1: Type: text/plain, Size: 371 bytes --]
On Thu, 11 Jun 2020 12:58:31 +0200, Oleg Nesterov wrote:
> On 06/11, Madhavan Srinivasan wrote:
> > On 6/10/20 8:37 PM, Oleg Nesterov wrote:
> > > > This is not consistent and this breaks
> > > > http://sourceware.org/systemtap/wiki/utrace/tests/user-regs-peekpoke
>
> this is 404.
Attaching the testcase, the CVS web interface no longer works on
sourceware.org.
Jan
[-- Attachment #2: user-regs-peekpoke.c --]
[-- Type: text/plain, Size: 10499 bytes --]
/* Test case for PTRACE_SETREGS modifying the requested ragisters.
x86* counterpart of the s390* testcase `user-area-access.c'.
This software is provided 'as-is', without any express or implied
warranty. In no event will the authors be held liable for any damages
arising from the use of this software.
Permission is granted to anyone to use this software for any purpose,
including commercial applications, and to alter it and redistribute it
freely. */
/* FIXME: EFLAGS should be tested restricted on the appropriate bits. */
#define _GNU_SOURCE 1
#if defined __powerpc__ || defined __sparc__
# define user_regs_struct pt_regs
#endif
#ifdef __ia64__
#define ia64_fpreg ia64_fpreg_DISABLE
#define pt_all_user_regs pt_all_user_regs_DISABLE
#endif /* __ia64__ */
#include <sys/ptrace.h>
#ifdef __ia64__
#undef ia64_fpreg
#undef pt_all_user_regs
#endif /* __ia64__ */
#include <linux/ptrace.h>
#include <sys/types.h>
#include <sys/user.h>
#if defined __i386__ || defined __x86_64__
#include <sys/debugreg.h>
#endif
#include <asm/unistd.h>
#include <assert.h>
#include <errno.h>
#include <error.h>
#include <unistd.h>
#include <signal.h>
#include <stdlib.h>
#include <stdio.h>
#include <sys/wait.h>
#include <sys/time.h>
#include <string.h>
#include <stddef.h>
/* ia64 has PTRACE_SETREGS but it has no USER_REGS_STRUCT. */
#if !defined PTRACE_SETREGS || defined __ia64__
int
main (void)
{
return 77;
}
#else /* PTRACE_SETREGS */
/* The minimal alignment we use for the random access ranges. */
#define REGALIGN (sizeof (long))
static pid_t child;
static void
cleanup (void)
{
if (child > 0)
kill (child, SIGKILL);
child = 0;
}
static void
handler_fail (int signo)
{
cleanup ();
signal (SIGABRT, SIG_DFL);
abort ();
}
int
main (void)
{
long l;
int status, i;
pid_t pid;
union
{
struct user_regs_struct user;
unsigned char byte[sizeof (struct user_regs_struct)];
} u, u2;
int start;
setbuf (stdout, NULL);
atexit (cleanup);
signal (SIGABRT, handler_fail);
signal (SIGALRM, handler_fail);
signal (SIGINT, handler_fail);
i = alarm (10);
assert (i == 0);
child = fork ();
switch (child)
{
case -1:
assert_perror (errno);
assert (0);
case 0:
l = ptrace (PTRACE_TRACEME, 0, NULL, NULL);
assert (l == 0);
// Prevent rt_sigprocmask() call called by glibc after raise().
syscall (__NR_tkill, getpid (), SIGSTOP);
assert (0);
default:
break;
}
pid = waitpid (child, &status, 0);
assert (pid == child);
assert (WIFSTOPPED (status));
assert (WSTOPSIG (status) == SIGSTOP);
/* Fetch U2 from the inferior. */
errno = 0;
# ifdef __sparc__
l = ptrace (PTRACE_GETREGS, child, &u2.user, NULL);
# else
l = ptrace (PTRACE_GETREGS, child, NULL, &u2.user);
# endif
assert_perror (errno);
assert (l == 0);
/* Initialize U with a pattern. */
for (i = 0; i < sizeof u.byte; i++)
u.byte[i] = i;
#ifdef __x86_64__
/* non-EFLAGS modifications fail with EIO, EFLAGS gets back different. */
u.user.eflags = u2.user.eflags;
u.user.cs = u2.user.cs;
u.user.ds = u2.user.ds;
u.user.es = u2.user.es;
u.user.fs = u2.user.fs;
u.user.gs = u2.user.gs;
u.user.ss = u2.user.ss;
u.user.fs_base = u2.user.fs_base;
u.user.gs_base = u2.user.gs_base;
/* RHEL-4 refuses to set too high (and invalid) PC values. */
u.user.rip = (unsigned long) handler_fail;
/* 2.6.25 always truncates and sign-extends orig_rax. */
u.user.orig_rax = (int) u.user.orig_rax;
#endif /* __x86_64__ */
#ifdef __i386__
/* These values get back different. */
u.user.xds = u2.user.xds;
u.user.xes = u2.user.xes;
u.user.xfs = u2.user.xfs;
u.user.xgs = u2.user.xgs;
u.user.xcs = u2.user.xcs;
u.user.eflags = u2.user.eflags;
u.user.xss = u2.user.xss;
/* RHEL-4 refuses to set too high (and invalid) PC values. */
u.user.eip = (unsigned long) handler_fail;
#endif /* __i386__ */
#ifdef __powerpc__
/* These fields are constrained. */
u.user.msr = u2.user.msr;
# ifdef __powerpc64__
u.user.softe = u2.user.softe;
# else
u.user.mq = u2.user.mq;
# endif /* __powerpc64__ */
u.user.trap = u2.user.trap;
u.user.dar = u2.user.dar;
u.user.dsisr = u2.user.dsisr;
u.user.result = u2.user.result;
#endif /* __powerpc__ */
/* Poke U. */
# ifdef __sparc__
l = ptrace (PTRACE_SETREGS, child, &u.user, NULL);
# else
l = ptrace (PTRACE_SETREGS, child, NULL, &u.user);
# endif
assert (l == 0);
/* Peek into U2. */
# ifdef __sparc__
l = ptrace (PTRACE_GETREGS, child, &u2.user, NULL);
# else
l = ptrace (PTRACE_GETREGS, child, NULL, &u2.user);
# endif
assert (l == 0);
/* Verify it matches. */
if (memcmp (&u.user, &u2.user, sizeof u.byte) != 0)
{
for (start = 0; start + REGALIGN <= sizeof u.byte; start += REGALIGN)
if (*(unsigned long *) (u.byte + start)
!= *(unsigned long *) (u2.byte + start))
printf ("\
mismatch at offset %#x: SETREGS wrote %lx GETREGS read %lx\n",
start, *(unsigned long *) (u.byte + start),
*(unsigned long *) (u2.byte + start));
return 1;
}
/* Reverse the pattern. */
for (i = 0; i < sizeof u.byte; i++)
u.byte[i] ^= -1;
#ifdef __x86_64__
/* non-EFLAGS modifications fail with EIO, EFLAGS gets back different. */
u.user.eflags = u2.user.eflags;
u.user.cs = u2.user.cs;
u.user.ds = u2.user.ds;
u.user.es = u2.user.es;
u.user.fs = u2.user.fs;
u.user.gs = u2.user.gs;
u.user.ss = u2.user.ss;
u.user.fs_base = u2.user.fs_base;
u.user.gs_base = u2.user.gs_base;
/* RHEL-4 refuses to set too high (and invalid) PC values. */
u.user.rip = (unsigned long) handler_fail;
/* 2.6.25 always truncates and sign-extends orig_rax. */
u.user.orig_rax = (int) u.user.orig_rax;
#endif /* __x86_64__ */
#ifdef __i386__
/* These values get back different. */
u.user.xds = u2.user.xds;
u.user.xes = u2.user.xes;
u.user.xfs = u2.user.xfs;
u.user.xgs = u2.user.xgs;
u.user.xcs = u2.user.xcs;
u.user.eflags = u2.user.eflags;
u.user.xss = u2.user.xss;
/* RHEL-4 refuses to set too high (and invalid) PC values. */
u.user.eip = (unsigned long) handler_fail;
#endif /* __i386__ */
#ifdef __powerpc__
/* These fields are constrained. */
u.user.msr = u2.user.msr;
# ifdef __powerpc64__
u.user.softe = u2.user.softe;
# else
u.user.mq = u2.user.mq;
# endif /* __powerpc64__ */
u.user.trap = u2.user.trap;
u.user.dar = u2.user.dar;
u.user.dsisr = u2.user.dsisr;
u.user.result = u2.user.result;
#endif /* __powerpc__ */
/* Poke U. */
# ifdef __sparc__
l = ptrace (PTRACE_SETREGS, child, &u.user, NULL);
# else
l = ptrace (PTRACE_SETREGS, child, NULL, &u.user);
# endif
assert (l == 0);
/* Peek into U2. */
# ifdef __sparc__
l = ptrace (PTRACE_GETREGS, child, &u2.user, NULL);
# else
l = ptrace (PTRACE_GETREGS, child, NULL, &u2.user);
# endif
assert (l == 0);
/* Verify it matches. */
if (memcmp (&u.user, &u2.user, sizeof u.byte) != 0)
{
for (start = 0; start + REGALIGN <= sizeof u.byte; start += REGALIGN)
if (*(unsigned long *) (u.byte + start)
!= *(unsigned long *) (u2.byte + start))
printf ("\
mismatch at offset %#x: SETREGS wrote %lx GETREGS read %lx\n",
start, *(unsigned long *) (u.byte + start),
*(unsigned long *) (u2.byte + start));
return 1;
}
/* Now try poking arbitrary ranges and verifying it reads back right.
We expect the U area is already a random enough pattern. */
for (start = 0; start + REGALIGN <= sizeof u.byte; start += REGALIGN)
{
for (i = start; i < start + REGALIGN; i++)
u.byte[i]++;
#ifdef __x86_64__
/* non-EFLAGS modifications fail with EIO, EFLAGS gets back different. */
u.user.eflags = u2.user.eflags;
u.user.cs = u2.user.cs;
u.user.ds = u2.user.ds;
u.user.es = u2.user.es;
u.user.fs = u2.user.fs;
u.user.gs = u2.user.gs;
u.user.ss = u2.user.ss;
u.user.fs_base = u2.user.fs_base;
u.user.gs_base = u2.user.gs_base;
/* RHEL-4 refuses to set too high (and invalid) PC values. */
u.user.rip = (unsigned long) handler_fail;
/* 2.6.25 always truncates and sign-extends orig_rax. */
u.user.orig_rax = (int) u.user.orig_rax;
#endif /* __x86_64__ */
#ifdef __i386__
/* These values get back different. */
u.user.xds = u2.user.xds;
u.user.xes = u2.user.xes;
u.user.xfs = u2.user.xfs;
u.user.xgs = u2.user.xgs;
u.user.xcs = u2.user.xcs;
u.user.eflags = u2.user.eflags;
u.user.xss = u2.user.xss;
/* RHEL-4 refuses to set too high (and invalid) PC values. */
u.user.eip = (unsigned long) handler_fail;
#endif /* __i386__ */
#ifdef __powerpc__
/* These fields are constrained. */
u.user.msr = u2.user.msr;
# ifdef __powerpc64__
u.user.softe = u2.user.softe;
# else
u.user.mq = u2.user.mq;
# endif /* __powerpc64__ */
u.user.trap = u2.user.trap;
u.user.dar = u2.user.dar;
u.user.dsisr = u2.user.dsisr;
u.user.result = u2.user.result;
if (start > offsetof (struct pt_regs, ccr))
break;
#endif /* __powerpc__ */
/* Poke U. */
l = ptrace (PTRACE_POKEUSER, child, (void *) (unsigned long) start,
(void *) *(unsigned long *) (u.byte + start));
if (l != 0)
error (1, errno, "PTRACE_POKEUSER at %x", start);
/* Peek into U2. */
# ifdef __sparc__
l = ptrace (PTRACE_GETREGS, child, &u2.user, NULL);
# else
l = ptrace (PTRACE_GETREGS, child, NULL, &u2.user);
# endif
assert (l == 0);
/* Verify it matches. */
if (memcmp (&u.user, &u2.user, sizeof u.byte) != 0)
{
printf ("mismatch at offset %#x: poked %lx but GETREGS read %lx\n",
start, *(unsigned long *) (u.byte + start),
*(unsigned long *) (u2.byte + start));
return 1;
}
}
/* Now try peeking arbitrary ranges and verifying it is the same.
We expect the U area is already a random enough pattern. */
for (start = 0; start + REGALIGN <= sizeof u.byte; start += REGALIGN)
{
/* Peek for the U comparation. */
errno = 0;
l = ptrace (PTRACE_PEEKUSER, child, (void *) (unsigned long) start,
NULL);
assert_perror (errno);
/* Verify it matches. */
if (*(unsigned long *) (u.byte + start) != l)
{
printf ("mismatch at offset %#x: poked %lx but peeked %lx\n",
start, *(unsigned long *) (u.byte + start), l);
return 1;
}
}
return 0;
}
#endif /* PTRACE_SETREGS */
^ permalink raw reply
* [PATCH] powerpc/kvm/book3s64/nested: Fix kernel crash with nested kvm
From: Aneesh Kumar K.V @ 2020-06-11 12:01 UTC (permalink / raw)
To: paulus, kvm-ppc; +Cc: Aneesh Kumar K.V, linuxppc-dev
__pa() do check for addr value passed and if < PAGE_OFFSET
results in BUG.
#define __pa(x) \
({ \
VIRTUAL_BUG_ON((unsigned long)(x) < PAGE_OFFSET); \
(unsigned long)(x) & 0x0fffffffffffffffUL; \
})
kvmhv_copy_tofrom_guest_radix() use a NULL value for
to/from to indicate direction of copy. Avoid calling __pa() if the
value is NULL
kernel BUG at arch/powerpc/kvm/book3s_64_mmu_radix.c:43!
cpu 0x70: Vector: 700 (Program Check) at [c0000018a2187360]
pc: c000000000161b30: __kvmhv_copy_tofrom_guest_radix+0x130/0x1f0
lr: c000000000161d5c: kvmhv_copy_from_guest_radix+0x3c/0x80
....
[c0000018a2187670] c000000000161d5c kvmhv_copy_from_guest_radix+0x3c/0x80
[c0000018a21876b0] c00000000014feb8 kvmhv_load_from_eaddr+0x48/0xc0
[c0000018a21876e0] c000000000135828 kvmppc_ld+0x98/0x1e0
[c0000018a2187780] c00000000013bc20 kvmppc_load_last_inst+0x50/0x90
[c0000018a21877b0] c00000000015e9e8 kvmppc_hv_emulate_mmio+0x288/0x2b0
[c0000018a2187810] c000000000164888 kvmppc_book3s_radix_page_fault+0xd8/0x2b0
[c0000018a21878c0] c00000000015ed8c kvmppc_book3s_hv_page_fault+0x37c/0x1050
[c0000018a2187a00] c00000000015a518 kvmppc_vcpu_run_hv+0xbb8/0x1080
[c0000018a2187b20] c00000000013d204 kvmppc_vcpu_run+0x34/0x50
[c0000018a2187b40] c00000000013949c kvm_arch_vcpu_ioctl_run+0x2fc/0x410
[c0000018a2187bd0] c00000000012a2a4 kvm_vcpu_ioctl+0x2b4/0x8f0
[c0000018a2187d50] c0000000005b12a4 ksys_ioctl+0xf4/0x150
[c0000018a2187da0] c0000000005b1328 sys_ioctl+0x28/0x80
[c0000018a2187dc0] c000000000030584 system_call_exception+0x104/0x1d0
[c0000018a2187e20] c00000000000ca68 system_call_common+0xe8/0x214
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
---
arch/powerpc/kvm/book3s_64_mmu_radix.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/arch/powerpc/kvm/book3s_64_mmu_radix.c b/arch/powerpc/kvm/book3s_64_mmu_radix.c
index 02219e28b1e4..84acb4769487 100644
--- a/arch/powerpc/kvm/book3s_64_mmu_radix.c
+++ b/arch/powerpc/kvm/book3s_64_mmu_radix.c
@@ -40,7 +40,8 @@ unsigned long __kvmhv_copy_tofrom_guest_radix(int lpid, int pid,
/* Can't access quadrants 1 or 2 in non-HV mode, call the HV to do it */
if (kvmhv_on_pseries())
return plpar_hcall_norets(H_COPY_TOFROM_GUEST, lpid, pid, eaddr,
- __pa(to), __pa(from), n);
+ (to != NULL) ? __pa(to): 0,
+ (from != NULL) ? __pa(from): 0, n);
quadrant = 1;
if (!pid)
--
2.26.2
^ permalink raw reply related
* Re: [PATCH v2] All arch: remove system call sys_sysctl
From: Eric W. Biederman @ 2020-06-11 11:43 UTC (permalink / raw)
To: Xiaoming Ni
Cc: linux-sh, catalin.marinas, paulus, ak, paulburton, geert,
mattst88, brgerst, acme, cyphar, viro, luto, tglx, surenb, rth,
young.liuyang, linux-parisc, rdunlap, linux-kernel, mcgrof,
linux-fsdevel, akpm, mark.rutland, linux-ia64, linux-xtensa,
jongk, linux, James.Bottomley, jcmvbkbc, linux-s390, ysato,
deller, yzaikin, mszeredi, gor, linux-alpha, linux-m68k,
linux-arm-kernel, chris, tony.luck, linux-api, zhouyanjie,
minchan, sargun, alexander.shishkin, heiko.carstens,
alex.huangjianhui, will, krzk, borntraeger, vbabka, samitolvanen,
flameeyes, ravi.bangoria, elver, keescook, arnd, bp, christian,
tsbogend, jiri, martin.petersen, yamada.masahiro, oleg,
sudeep.holla, olof, shawnguo, davem, bauerman, dalias, fenghua.yu,
peterz, dhowells, hpa, sparclinux, jolsa, svens, x86, linux,
mingo, naveen.n.rao, paulmck, sfr, npiggin, namhyung, dvyukov,
axboe, monstr, haolee.swjtu, linux-mips, ink, linuxppc-dev
In-Reply-To: <1591847640-124894-1-git-send-email-nixiaoming@huawei.com>
Xiaoming Ni <nixiaoming@huawei.com> writes:
> Since the commit 61a47c1ad3a4dc ("sysctl: Remove the sysctl system call"),
> sys_sysctl is actually unavailable: any input can only return an error.
>
> We have been warning about people using the sysctl system call for years
> and believe there are no more users. Even if there are users of this
> interface if they have not complained or fixed their code by now they
> probably are not going to, so there is no point in warning them any
> longer.
>
> So completely remove sys_sysctl on all architectures.
>
> Signed-off-by: Xiaoming Ni <nixiaoming@huawei.com>
>
> changes in v2:
> According to Kees Cook's suggestion, completely remove sys_sysctl on all arch
> According to Eric W. Biederman's suggestion, update the commit log
>
> V1: https://lore.kernel.org/lkml/1591683605-8585-1-git-send-email-nixiaoming@huawei.com/
> Delete the code of sys_sysctl and return -ENOSYS directly at the function entry
> ---
> include/uapi/linux/sysctl.h | 15 --
[snip]
> diff --git a/include/uapi/linux/sysctl.h b/include/uapi/linux/sysctl.h
> index 27c1ed2..84b44c3 100644
> --- a/include/uapi/linux/sysctl.h
> +++ b/include/uapi/linux/sysctl.h
> @@ -27,21 +27,6 @@
> #include <linux/types.h>
> #include <linux/compiler.h>
>
> -#define CTL_MAXNAME 10 /* how many path components do we allow in a
> - call to sysctl? In other words, what is
> - the largest acceptable value for the nlen
> - member of a struct __sysctl_args to have? */
> -
> -struct __sysctl_args {
> - int __user *name;
> - int nlen;
> - void __user *oldval;
> - size_t __user *oldlenp;
> - void __user *newval;
> - size_t newlen;
> - unsigned long __unused[4];
> -};
> -
> /* Define sysctl names first */
>
> /* Top-level names: */
[snip]
The uapi header change does not make sense. The entire point of the
header is to allow userspace programs to be able to call sys_sysctl.
It either needs to all stay or all go.
As the concern with the uapi header is about userspace programs being
able to compile please leave the header for now.
We should leave auditing userspace and seeing if userspace code will
still compile if we remove this header for a separate patch. The
concerns and justifications for the uapi header are completely different
then for the removing the sys_sysctl implementation.
Otherwise
Acked-by: "Eric W. Biederman" <ebiederm@xmission.com>
Eric
^ permalink raw reply
* [PATCH] powerpc/64: indirect function call use bctrl rather than blrl in ret_from_kernel_thread
From: Nicholas Piggin @ 2020-06-11 12:11 UTC (permalink / raw)
To: linuxppc-dev; +Cc: Nicholas Piggin
blrl is not recommended to use as an indirect function call, as it may
corrupt the link stack predictor.
This is not a performance critical path but this should be fixed for
consistency.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
arch/powerpc/kernel/entry_64.S | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/arch/powerpc/kernel/entry_64.S b/arch/powerpc/kernel/entry_64.S
index 223c4f008e63..f59a17471d4d 100644
--- a/arch/powerpc/kernel/entry_64.S
+++ b/arch/powerpc/kernel/entry_64.S
@@ -400,12 +400,12 @@ _GLOBAL(ret_from_fork)
_GLOBAL(ret_from_kernel_thread)
bl schedule_tail
REST_NVGPRS(r1)
- mtlr r14
+ mtctr r14
mr r3,r15
#ifdef PPC64_ELF_ABI_v2
mr r12,r14
#endif
- blrl
+ bctrl
li r3,0
b .Lsyscall_exit
--
2.23.0
^ permalink raw reply related
* Re: [PATCH] powerpc/64: indirect function call use bctrl rather than blrl in ret_from_kernel_thread
From: Christophe Leroy @ 2020-06-11 12:26 UTC (permalink / raw)
To: Nicholas Piggin, linuxppc-dev
In-Reply-To: <20200611121119.1015740-1-npiggin@gmail.com>
Le 11/06/2020 à 14:11, Nicholas Piggin a écrit :
> blrl is not recommended to use as an indirect function call, as it may
> corrupt the link stack predictor.
>
> This is not a performance critical path but this should be fixed for
> consistency.
There's exactly the same in entry_32.S
Should it be changed there too ... for consistency :) ?
ppc32 also uses blrl for calling syscall handler, should it be changed
as well ?
Christophe
>
> Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
> ---
> arch/powerpc/kernel/entry_64.S | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/arch/powerpc/kernel/entry_64.S b/arch/powerpc/kernel/entry_64.S
> index 223c4f008e63..f59a17471d4d 100644
> --- a/arch/powerpc/kernel/entry_64.S
> +++ b/arch/powerpc/kernel/entry_64.S
> @@ -400,12 +400,12 @@ _GLOBAL(ret_from_fork)
> _GLOBAL(ret_from_kernel_thread)
> bl schedule_tail
> REST_NVGPRS(r1)
> - mtlr r14
> + mtctr r14
> mr r3,r15
> #ifdef PPC64_ELF_ABI_v2
> mr r12,r14
> #endif
> - blrl
> + bctrl
> li r3,0
> b .Lsyscall_exit
>
>
^ permalink raw reply
* Re: PowerPC KVM-PR issue
From: Christian Zigotzky @ 2020-06-11 14:47 UTC (permalink / raw)
To: linuxppc-dev, npiggin, kvm-ppc@vger.kernel.org
Cc: Darren Stevens, R.T.Dickinson, Christian Zigotzky
In-Reply-To: <7e859f68-9455-f98f-1fa3-071619fa1731@xenosoft.de>
On 10 June 2020 at 01:23 pm, Christian Zigotzky wrote:
> On 10 June 2020 at 11:06 am, Christian Zigotzky wrote:
>> On 10 June 2020 at 00:18 am, Christian Zigotzky wrote:
>>> Hello,
>>>
>>> KVM-PR doesn't work anymore on my Nemo board [1]. I figured out that
>>> the Git kernels and the kernel 5.7 are affected.
>>>
>>> Error message: Fienix kernel: kvmppc_exit_pr_progint: emulation at
>>> 700 failed (00000000)
>>>
>>> I can boot virtual QEMU PowerPC machines with KVM-PR with the kernel
>>> 5.6 without any problems on my Nemo board.
>>>
>>> I tested it with QEMU 2.5.0 and QEMU 5.0.0 today.
>>>
>>> Could you please check KVM-PR on your PowerPC machine?
>>>
>>> Thanks,
>>> Christian
>>>
>>> [1] https://en.wikipedia.org/wiki/AmigaOne_X1000
>>
>> I figured out that the PowerPC updates 5.7-1 [1] are responsible for
>> the KVM-PR issue. Please test KVM-PR on your PowerPC machines and
>> check the PowerPC updates 5.7-1 [1].
>>
>> Thanks
>>
>> [1]
>> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=d38c07afc356ddebaa3ed8ecb3f553340e05c969
>>
>>
> I tested the latest Git kernel with Mac-on-Linux/KVM-PR today.
> Unfortunately I can't use KVM-PR with MoL anymore because of this
> issue (see screenshots [1]). Please check the PowerPC updates 5.7-1.
>
> Thanks
>
> [1]
> -
> https://i.pinimg.com/originals/0c/b3/64/0cb364a40241fa2b7f297d4272bbb8b7.png
> -
> https://i.pinimg.com/originals/9a/61/d1/9a61d170b1c9f514f7a78a3014ffd18f.png
>
Hi All,
I bisected today because of the KVM-PR issue.
Result:
9600f261acaaabd476d7833cec2dd20f2919f1a0 is the first bad commit
commit 9600f261acaaabd476d7833cec2dd20f2919f1a0
Author: Nicholas Piggin <npiggin@gmail.com>
Date: Wed Feb 26 03:35:21 2020 +1000
powerpc/64s/exception: Move KVM test to common code
This allows more code to be moved out of unrelocated regions. The
system call KVMTEST is changed to be open-coded and remain in the
tramp area to avoid having to move it to entry_64.S. The custom nature
of the system call entry code means the hcall case can be made more
streamlined than regular interrupt handlers.
mpe: Incorporate fix from Nick:
Moving KVM test to the common entry code missed the case of HMI and
MCE, which do not do __GEN_COMMON_ENTRY (because they don't want to
switch to virt mode).
This means a MCE or HMI exception that is taken while KVM is running a
guest context will not be switched out of that context, and KVM won't
be notified. Found by running sigfuz in guest with patched host on
POWER9 DD2.3, which causes some TM related HMI interrupts (which are
expected and supposed to be handled by KVM).
This fix adds a __GEN_REALMODE_COMMON_ENTRY for those handlers to add
the KVM test. This makes them look a little more like other handlers
that all use __GEN_COMMON_ENTRY.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link:
https://lore.kernel.org/r/20200225173541.1549955-13-npiggin@gmail.com
:040000 040000 ec21cec22d165f8696d69532734cb2985d532cb0
87dd49a9cd7202ec79350e8ca26cea01f1dbd93d M arch
-----
The following commit is the problem: powerpc/64s/exception: Move KVM
test to common code [1]
These changes were included in the PowerPC updates 5.7-1. [2]
Another test:
git checkout d38c07afc356ddebaa3ed8ecb3f553340e05c969 (PowerPC updates
5.7-1 [2] ) -> KVM-PR doesn't work.
After that: git revert d38c07afc356ddebaa3ed8ecb3f553340e05c969 -m 1 ->
KVM-PR works.
Could you please check the first bad commit? [1]
Thanks,
Christian
[1]
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=9600f261acaaabd476d7833cec2dd20f2919f1a0
[2]
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=d38c07afc356ddebaa3ed8ecb3f553340e05c969
^ permalink raw reply
* Re: [PATCH v11 5/6] ndctl/papr_scm, uapi: Add support for PAPR nvdimm specific methods
From: Vaibhav Jain @ 2020-06-11 18:03 UTC (permalink / raw)
To: Dan Williams
Cc: Santosh Sivaraj, linux-nvdimm, Aneesh Kumar K . V,
Linux Kernel Mailing List, Oliver O'Halloran, linuxppc-dev
In-Reply-To: <CAPcyv4h_0qSqS2P0=vNk9KWy-=WZq-giNupks+Q0+wmYVt9iLA@mail.gmail.com>
Dan Williams <dan.j.williams@intel.com> writes:
> On Wed, Jun 10, 2020 at 5:10 AM Vaibhav Jain <vaibhav@linux.ibm.com> wrote:
>>
>> Dan Williams <dan.j.williams@intel.com> writes:
>>
>> > On Tue, Jun 9, 2020 at 10:54 AM Vaibhav Jain <vaibhav@linux.ibm.com> wrote:
>> >>
>> >> Thanks Dan for the consideration and taking time to look into this.
>> >>
>> >> My responses below:
>> >>
>> >> Dan Williams <dan.j.williams@intel.com> writes:
>> >>
>> >> > On Mon, Jun 8, 2020 at 5:16 PM kernel test robot <lkp@intel.com> wrote:
>> >> >>
>> >> >> Hi Vaibhav,
>> >> >>
>> >> >> Thank you for the patch! Perhaps something to improve:
>> >> >>
>> >> >> [auto build test WARNING on powerpc/next]
>> >> >> [also build test WARNING on linus/master v5.7 next-20200605]
>> >> >> [cannot apply to linux-nvdimm/libnvdimm-for-next scottwood/next]
>> >> >> [if your patch is applied to the wrong git tree, please drop us a note to help
>> >> >> improve the system. BTW, we also suggest to use '--base' option to specify the
>> >> >> base tree in git format-patch, please see https://stackoverflow.com/a/37406982]
>> >> >>
>> >> >> url: https://github.com/0day-ci/linux/commits/Vaibhav-Jain/powerpc-papr_scm-Add-support-for-reporting-nvdimm-health/20200607-211653
>> >> >> base: https://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux.git next
>> >> >> config: powerpc-randconfig-r016-20200607 (attached as .config)
>> >> >> compiler: clang version 11.0.0 (https://github.com/llvm/llvm-project e429cffd4f228f70c1d9df0e5d77c08590dd9766)
>> >> >> reproduce (this is a W=1 build):
>> >> >> wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
>> >> >> chmod +x ~/bin/make.cross
>> >> >> # install powerpc cross compiling tool for clang build
>> >> >> # apt-get install binutils-powerpc-linux-gnu
>> >> >> # save the attached .config to linux build tree
>> >> >> COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=powerpc
>> >> >>
>> >> >> If you fix the issue, kindly add following tag as appropriate
>> >> >> Reported-by: kernel test robot <lkp@intel.com>
>> >> >>
>> >> >> All warnings (new ones prefixed by >>, old ones prefixed by <<):
>> >> >>
>> >> >> In file included from <built-in>:1:
>> >> >> >> ./usr/include/asm/papr_pdsm.h:69:20: warning: field 'hdr' with variable sized type 'struct nd_cmd_pkg' not at the end of a struct or class is a GNU extension [-Wgnu-variable-sized-type-not-at-end]
>> >> >> struct nd_cmd_pkg hdr; /* Package header containing sub-cmd */
>> >> >
>> >> > Hi Vaibhav,
>> >> >
>> >> [.]
>> >> > This looks like it's going to need another round to get this fixed. I
>> >> > don't think 'struct nd_pdsm_cmd_pkg' should embed a definition of
>> >> > 'struct nd_cmd_pkg'. An instance of 'struct nd_cmd_pkg' carries a
>> >> > payload that is the 'pdsm' specifics. As the code has it now it's
>> >> > defined as a superset of 'struct nd_cmd_pkg' and the compiler warning
>> >> > is pointing out a real 'struct' organization problem.
>> >> >
>> >> > Given the soak time needed in -next after the code is finalized this
>> >> > there's no time to do another round of updates and still make the v5.8
>> >> > merge window.
>> >>
>> >> Agreed that this looks bad, a solution will probably need some more
>> >> review cycles resulting in this series missing the merge window.
>> >>
>> >> I am investigating into the possible solutions for this reported issue
>> >> and made few observations:
>> >>
>> >> I see command pkg for Intel, Hpe, Msft and Hyperv families using a
>> >> similar layout of embedding nd_cmd_pkg at the head of the
>> >> command-pkg. struct nd_pdsm_cmd_pkg is following the same pattern.
>> >>
>> >> struct nd_pdsm_cmd_pkg {
>> >> struct nd_cmd_pkg hdr;
>> >> /* other members */
>> >> };
>> >>
>> >> struct ndn_pkg_msft {
>> >> struct nd_cmd_pkg gen;
>> >> /* other members */
>> >> };
>> >> struct nd_pkg_intel {
>> >> struct nd_cmd_pkg gen;
>> >> /* other members */
>> >> };
>> >> struct ndn_pkg_hpe1 {
>> >> struct nd_cmd_pkg gen;
>> >> /* other members */
>> [.]
>> >
>> > In those cases the other members are a union and there is no second
>> > variable length array. Perhaps that is why those definitions are not
>> > getting flagged? I'm not seeing anything in ndctl build options that
>> > would explicitly disable this warning, but I'm not sure if the ndctl
>> > build environment is missing this build warning by accident.
>>
>> I tried building ndctl master with clang-10 with CC=clang and
>> CFLAGS="". Seeing the same warning messages reported for all command
>> package struct for existing command families.
>>
>> ./hpe1.h:334:20: warning: field 'gen' with variable sized type 'struct nd_cmd_pkg' not at the end of a struct or class is a GNU extension [-Wgnu-variable-sized-type-not-at-end]
>> struct nd_cmd_pkg gen;
>> ^
>> ./msft.h:59:20: warning: field 'gen' with variable sized type 'struct nd_cmd_pkg' not at the end of a struct or class is a GNU extension [-Wgnu-variable-sized-type-not-at-end]
>> struct nd_cmd_pkg gen;
>> ^
>> ./hyperv.h:34:20: warning: field 'gen' with variable sized type 'struct nd_cmd_pkg' not at the end of a struct or class is a GNU extension [-Wgnu-variable-sized-type-not-at-end]
>> struct nd_cmd_pkg gen;
>> ^
>
[.]
> Good to know, but ugh now I'm just realizing this warning is only
> coming from clang and not gcc. Frankly I'm not as concerned about
> clang warnings and I should have been more careful looking at the
> source of this warning.
Thanks for acknowledging this.
I digged deeper into this today and it seems that with clang, kernel code
is compiled with diagnostic flag '-Wno-gnu' [1][2] which implicitly implies
'-Wno-gnu-variable-sized-type-not-at-end'. Hence the structures with
flexible arrays not the end of containing struct are not flagged in
kernel code.
[1] https://github.com/torvalds/linux/blob/b29482fde649c72441d5478a4ea2c52c56d97a5e/Makefile#L788
[2] https://clang.llvm.org/docs/DiagnosticsReference.html#wgnu
However this dignostic flag is not used for uapi header test hence
build robot emmited this warning while trying to test compile
'papr_pdsm.h' uapi header.
>
>> >
>> > Those variable size payloads are also not being used in any code paths
>> > that would look at the size of the command payload, like the kernel
>> > ioctl() path. The payload validation code needs static sizes and the
>> > payload parsing code wants to cast the payload to a known type. I
>> > don't think you can use the same struct definition for both those
>> > cases which is why the ndctl parsing code uses the union layout, but
>> > the kernel command marshaling code does strict layering.
>> Even if I switch to union layout and replacing the flexible array 'payload'
>> at end to a fixed size array something like below, I still see
>> '-Wgnu-variable-sized-type-not-at-end' warning reported by clang:
>>
>> union nd_pdsm_cmd_payload {
>> struct nd_papr_pdsm_health health;
>> __u8 buf[ND_PDSM_PAYLOAD_MAX_SIZE];
>> };
>>
>> struct nd_pdsm_cmd_pkg {
>> struct nd_cmd_pkg hdr; /* Package header containing sub-cmd */
>> __s32 cmd_status; /* Out: Sub-cmd status returned back */
>> __u16 reserved[2]; /* Ignored and to be used in future */
>> union nd_pdsm_cmd_payload payload;
>> } __attribute__((packed));
>
> Even though this is a clang warning, I'm still not sure it's a good
> idea to copy the ndctl approach into the kernel. Could you perhaps
> handle this the way that drivers/acpi/nfit/intel.c handles submitting
> commands through the ND_CMD_CALL interface, i.e. by just defining the
> command locally like this (from intel_security_flags()):
>
> struct {
> struct nd_cmd_pkg pkg;
> struct nd_intel_get_security_state cmd;
> } nd_cmd = {
> .pkg = {
> .nd_command = NVDIMM_INTEL_GET_SECURITY_STATE,
> .nd_family = NVDIMM_FAMILY_INTEL,
> .nd_size_out =
> sizeof(struct nd_intel_get_security_state),
> .nd_fw_size =
> sizeof(struct nd_intel_get_security_state),
> },
> };
>
> That way it's clear that the payload is 'struct
> nd_intel_get_security_state' without needing to have a pre-existing
> definition. For parsing in the ioctl path I think it's clearer to cast
> the payload to the local pdsm structure for the command.
>
In userspace libndctl code doesnt use '-Wno-gnu' (yet) hence this would
still be reported as a warning. Also for each pdsm I want a consistent
way to report errors back. Above would force me to define a 'status'
field to report error in every pdsm payload struct.
I have two possible solutions to work around the clang and 'status'
field issue:
1. I remove instance of 'struct nd_cmd_pkg' from 'nd_pdsm_cmd_pkg' like
below. This should make the clang warning go away and I still keep the
'cmd_status' field.
struct nd_pdsm_cmd_pkg {
__s32 cmd_status; /* Out: Sub-cmd status returned back */
__u16 reserved[2]; /* Ignored and to be used in future */
__u8 payload[]; /* In/Out: Sub-cmd data buffer */
} __packed;
When sending CMD_CALL allocate and populate an envelop large enough to
hold generic nd_cmd header, pdsm header and the payload like below:
0 64 72 255
+------------+-----------------+--------------------------------+
|nd_cmd_pkg | nd_pdsm_cmd_pkg | payload |
+------------+-----------------+--------------------------------+
pdsm handling code introduced in this patchset already uses helpers to
convert nd_cmd_pkg -> nd_pdsm_cmd_pkg and nd_pdsm_cmd_pkg -> payload. So
the impact to the patchset should be contained to these helper
functions. There are places in pdsm service functions that directly
access members of nd_cmd_pkg which may need some tweaking.
2. I open-code members of 'struct nd_cmd_pkg' at start of 'struct
nd_pdsm_cmd_pkg' except the nd_payload field like below. This struct
should ensure ABI compatibility with 'struct nd_cmd_pkg'.
struct nd_pdsm_cmd_pkg {
__u64 nd_family; /* family of commands */
__u64 nd_command;
__u32 nd_size_in; /* INPUT: size of input args */
__u32 nd_size_out; /* INPUT: size of payload */
__u32 nd_reserved2[9]; /* reserved must be zero */
__u32 nd_fw_size; /* OUTPUT: size fw wants to return */
__s32 cmd_status; /* Out: Sub-cmd status returned back */
__u16 reserved[2]; /* Ignored and to be used in future */
__u8 payload[]; /* In/Out: Sub-cmd data buffer */
} __packed;
BULD_BUG_ON((sizeof(struct nd_cmd_pkg) + 8) > sizeof(struct nd_pdsm_cmd_pkg))
>>
>>
>> >
>> >> };
>> >>
>> >> Even though other command families implement similar command-package
>> >> layout they were not flagged (yet) as they are (I am guessing) serviced
>> >> in vendor acpi drivers rather than in kernel like in case of papr-scm
>> >> command family.
>> >
>> > I sincerely hope there are no vendor acpi kernel drivers outside of
>> > the upstream one.
>> Apologies if I was not clear. Was referring to nvdimm vendor uefi
>> drivers which ultimately service the DSM commands. Since CMD_CALL serves
>> as a conduit to send the command payload to these vendor drivers,
>> libnvdimm never needs to peek into the nd_cmd_pkg.payload
>> field. Consequently nfit module never hit this warning in kernel before.
>
> Ah, understood, and no, that's not the root reason this problem is not
> present in the kernel. The expectation is that any payload that the
> kernel would need to consider should probably have a kernel specific
> translation defined. For example,
>
> ND_CMD_GET_CONFIG_SIZE
> ND_CMD_GET_CONFIG_DATA
> ND_CMD_SET_CONFIG_DATA
>
> ...are payloads that the kernel needs to understand. However instead
> of supporting each way to read / write the label area the expectation
> is that all drivers just parse this common kernel payload and
> translate it if necessary. For example ND_CMD_{GET,SET}_CONFIG_DATA is
> optionally translated to the Intel DSMs, generic ACPI _LSR/_LSW, or
> papr_scm_meta_{get,set}.
>
> Outside of validating command numbers the expectation is that the
> kernel does not validate/consume the contents of the ND_CMD_CALL
> payload, it passes it to the backend where ACPI DSM or pdsm protocol
> takes over.
Right, but arent those independent IOCTLs to libnvdimm with a fixed
predefined struct thats exchanged with libndctl. Not sure how can that
help with exchanging pdsms with papr_scm that are variable in length and
can only rely on CMD_CALL ioctl.
--
Cheers
~ Vaibhav
^ permalink raw reply
* Re: [PATCH v5 2/4] riscv: Introduce CONFIG_RELOCATABLE
From: Alex Ghiti @ 2020-06-11 19:43 UTC (permalink / raw)
To: Jerome Forissier, Michael Ellerman, Benjamin Herrenschmidt,
Paul Mackerras, Paul Walmsley, Palmer Dabbelt, Albert Ou,
Anup Patel, Atish Patra, Zong Li, linux-kernel, linuxppc-dev,
linux-riscv
Cc: Anup Patel
In-Reply-To: <b588dd9e-dff8-3458-0c7d-149e3990bca7@forissier.org>
Hi Jerome,
Le 6/10/20 à 10:10 AM, Jerome Forissier a écrit :
> On 6/7/20 9:59 AM, Alexandre Ghiti wrote:
> [...]
>
>> +config RELOCATABLE
>> + bool
>> + depends on MMU
>> + help
>> + This builds a kernel as a Position Independent Executable (PIE),
>> + which retains all relocation metadata required to relocate the
>> + kernel binary at runtime to a different virtual address than the
>> + address it was linked at.
>> + Since RISCV uses the RELA relocation format, this requires a
>> + relocation pass at runtime even if the kernel is loaded at the
>> + same address it was linked at.
> Is this true? I thought that the GNU linker would write the "proper"
> values by default, contrary to the LLVM linker (ld.lld) which would need
> a special flag: --apply-dynamic-relocs (by default the relocated places
> are set to zero). At least, it is my experience with Aarch64 on a
> different project. So, sorry if I'm talking nonsense here -- I have not
> looked at the details.
>
>
It seems that you're right, at least for aarch64 since they specifically
specify the --no-apply-dynamic-relocs option. I retried to boot without
relocating at runtime, and it fails on riscv. Can this be arch specific ?
Thanks,
Alex
^ permalink raw reply
* Re: Linux powerpc new system call instruction and ABI
From: Segher Boessenkool @ 2020-06-11 21:02 UTC (permalink / raw)
To: Nicholas Piggin; +Cc: libc-dev, linux-api, linuxppc-dev, musl
In-Reply-To: <20200611081203.995112-1-npiggin@gmail.com>
Hi!
On Thu, Jun 11, 2020 at 06:12:01PM +1000, Nicholas Piggin wrote:
> Calling convention
> ------------------
> The proposal is for scv 0 to provide the standard Linux system call ABI
> with the following differences from sc convention[1]:
>
> - lr is to be volatile across scv calls. This is necessary because the
> scv instruction clobbers lr. From previous discussion, this should be
> possible to deal with in GCC clobbers and CFI.
>
> - cr1 and cr5-cr7 are volatile. This matches the C ABI and would allow the
> kernel system call exit to avoid restoring the volatile cr registers
> (although we probably still would anyway to avoid information leaks).
>
> - Error handling: The consensus among kernel, glibc, and musl is to move to
> using negative return values in r3 rather than CR0[SO]=1 to indicate error,
> which matches most other architectures, and is closer to a function call.
What about cr0 then? Will it be volatile as well (exactly like for
function calls)?
> Notes
> -----
> - r0,r4-r8 are documented as volatile in the ABI, but the kernel patch as
> submitted currently preserves them. This is to leave room for deciding
> which way to go with these.
The kernel has to set it to *something* that doesn't leak information ;-)
Segher
^ permalink raw reply
* Re: [PATCH v2] All arch: remove system call sys_sysctl
From: Rich Felker @ 2020-06-11 16:39 UTC (permalink / raw)
To: Eric W. Biederman
Cc: linux-sh, catalin.marinas, paulus, ak, paulburton, geert,
mattst88, brgerst, acme, cyphar, viro, luto, tglx, surenb, rth,
young.liuyang, linux-parisc, rdunlap, linux-kernel, mcgrof,
linux-fsdevel, akpm, mark.rutland, linux-ia64, linux-xtensa,
jongk, linux, James.Bottomley, jcmvbkbc, linux-s390, ysato,
deller, yzaikin, Xiaoming Ni, mszeredi, gor, linux-alpha,
linux-m68k, linux-arm-kernel, chris, tony.luck, linux-api,
zhouyanjie, minchan, sargun, alexander.shishkin, heiko.carstens,
alex.huangjianhui, will, krzk, borntraeger, vbabka, samitolvanen,
flameeyes, ravi.bangoria, elver, keescook, arnd, bp, christian,
tsbogend, jiri, martin.petersen, yamada.masahiro, oleg,
sudeep.holla, olof, shawnguo, davem, bauerman, fenghua.yu, peterz,
dhowells, hpa, sparclinux, jolsa, svens, x86, linux, mingo,
naveen.n.rao, paulmck, sfr, npiggin, namhyung, dvyukov, axboe,
monstr, haolee.swjtu, linux-mips, ink, linuxppc-dev
In-Reply-To: <87ftb1u8u3.fsf@x220.int.ebiederm.org>
On Thu, Jun 11, 2020 at 06:43:00AM -0500, Eric W. Biederman wrote:
> Xiaoming Ni <nixiaoming@huawei.com> writes:
>
> > Since the commit 61a47c1ad3a4dc ("sysctl: Remove the sysctl system call"),
> > sys_sysctl is actually unavailable: any input can only return an error.
> >
> > We have been warning about people using the sysctl system call for years
> > and believe there are no more users. Even if there are users of this
> > interface if they have not complained or fixed their code by now they
> > probably are not going to, so there is no point in warning them any
> > longer.
> >
> > So completely remove sys_sysctl on all architectures.
>
>
>
> >
> > Signed-off-by: Xiaoming Ni <nixiaoming@huawei.com>
> >
> > changes in v2:
> > According to Kees Cook's suggestion, completely remove sys_sysctl on all arch
> > According to Eric W. Biederman's suggestion, update the commit log
> >
> > V1: https://lore.kernel.org/lkml/1591683605-8585-1-git-send-email-nixiaoming@huawei.com/
> > Delete the code of sys_sysctl and return -ENOSYS directly at the function entry
> > ---
> > include/uapi/linux/sysctl.h | 15 --
> [snip]
>
> > diff --git a/include/uapi/linux/sysctl.h b/include/uapi/linux/sysctl.h
> > index 27c1ed2..84b44c3 100644
> > --- a/include/uapi/linux/sysctl.h
> > +++ b/include/uapi/linux/sysctl.h
> > @@ -27,21 +27,6 @@
> > #include <linux/types.h>
> > #include <linux/compiler.h>
> >
> > -#define CTL_MAXNAME 10 /* how many path components do we allow in a
> > - call to sysctl? In other words, what is
> > - the largest acceptable value for the nlen
> > - member of a struct __sysctl_args to have? */
> > -
> > -struct __sysctl_args {
> > - int __user *name;
> > - int nlen;
> > - void __user *oldval;
> > - size_t __user *oldlenp;
> > - void __user *newval;
> > - size_t newlen;
> > - unsigned long __unused[4];
> > -};
> > -
> > /* Define sysctl names first */
> >
> > /* Top-level names: */
> [snip]
>
> The uapi header change does not make sense. The entire point of the
> header is to allow userspace programs to be able to call sys_sysctl.
> It either needs to all stay or all go.
>
> As the concern with the uapi header is about userspace programs being
> able to compile please leave the header for now.
>
> We should leave auditing userspace and seeing if userspace code will
> still compile if we remove this header for a separate patch. The
> concerns and justifications for the uapi header are completely different
> then for the removing the sys_sysctl implementation.
>
> Otherwise
> Acked-by: "Eric W. Biederman" <ebiederm@xmission.com>
The UAPI header should be kept because it's defining an API not just
for the kernel the headers are supplied with, but for all past
kernels. In particular programs needing a failsafe CSPRNG source that
works on old kernels may (do) use this as a fallback only if modern
syscalls are missing. Removing the syscall is no problem since it
won't be used, but if you remove the types/macros from the UAPI
headers, they'll have to copy that into their own sources.
Rich
^ permalink raw reply
* Re: [PATCH v2] All arch: remove system call sys_sysctl
From: Rich Felker @ 2020-06-11 17:20 UTC (permalink / raw)
To: Eric W. Biederman
Cc: linux-sh, catalin.marinas, paulus, ak, paulburton, geert,
mattst88, brgerst, acme, cyphar, viro, luto, tglx, surenb, rth,
young.liuyang, linux-parisc, rdunlap, linux-kernel, mcgrof,
linux-fsdevel, akpm, mark.rutland, linux-ia64, linux-xtensa,
jongk, linux, James.Bottomley, jcmvbkbc, linux-s390, ysato,
deller, yzaikin, Xiaoming Ni, mszeredi, gor, linux-alpha,
linux-m68k, linux-arm-kernel, chris, tony.luck, linux-api,
zhouyanjie, minchan, sargun, alexander.shishkin, heiko.carstens,
alex.huangjianhui, will, krzk, borntraeger, vbabka, samitolvanen,
flameeyes, ravi.bangoria, elver, keescook, arnd, bp, christian,
tsbogend, jiri, martin.petersen, yamada.masahiro, oleg,
sudeep.holla, olof, shawnguo, davem, bauerman, fenghua.yu, peterz,
dhowells, hpa, sparclinux, jolsa, svens, x86, linux, mingo,
naveen.n.rao, paulmck, sfr, npiggin, namhyung, dvyukov, axboe,
monstr, haolee.swjtu, linux-mips, ink, linuxppc-dev
In-Reply-To: <87ftb1sfjc.fsf@x220.int.ebiederm.org>
On Thu, Jun 11, 2020 at 12:01:11PM -0500, Eric W. Biederman wrote:
> Rich Felker <dalias@libc.org> writes:
>
> > On Thu, Jun 11, 2020 at 06:43:00AM -0500, Eric W. Biederman wrote:
> >> Xiaoming Ni <nixiaoming@huawei.com> writes:
> >>
> >> > Since the commit 61a47c1ad3a4dc ("sysctl: Remove the sysctl system call"),
> >> > sys_sysctl is actually unavailable: any input can only return an error.
> >> >
> >> > We have been warning about people using the sysctl system call for years
> >> > and believe there are no more users. Even if there are users of this
> >> > interface if they have not complained or fixed their code by now they
> >> > probably are not going to, so there is no point in warning them any
> >> > longer.
> >> >
> >> > So completely remove sys_sysctl on all architectures.
> >>
> >>
> >>
> >> >
> >> > Signed-off-by: Xiaoming Ni <nixiaoming@huawei.com>
> >> >
> >> > changes in v2:
> >> > According to Kees Cook's suggestion, completely remove sys_sysctl on all arch
> >> > According to Eric W. Biederman's suggestion, update the commit log
> >> >
> >> > V1: https://lore.kernel.org/lkml/1591683605-8585-1-git-send-email-nixiaoming@huawei.com/
> >> > Delete the code of sys_sysctl and return -ENOSYS directly at the function entry
> >> > ---
> >> > include/uapi/linux/sysctl.h | 15 --
> >> [snip]
> >>
> >> > diff --git a/include/uapi/linux/sysctl.h b/include/uapi/linux/sysctl.h
> >> > index 27c1ed2..84b44c3 100644
> >> > --- a/include/uapi/linux/sysctl.h
> >> > +++ b/include/uapi/linux/sysctl.h
> >> > @@ -27,21 +27,6 @@
> >> > #include <linux/types.h>
> >> > #include <linux/compiler.h>
> >> >
> >> > -#define CTL_MAXNAME 10 /* how many path components do we allow in a
> >> > - call to sysctl? In other words, what is
> >> > - the largest acceptable value for the nlen
> >> > - member of a struct __sysctl_args to have? */
> >> > -
> >> > -struct __sysctl_args {
> >> > - int __user *name;
> >> > - int nlen;
> >> > - void __user *oldval;
> >> > - size_t __user *oldlenp;
> >> > - void __user *newval;
> >> > - size_t newlen;
> >> > - unsigned long __unused[4];
> >> > -};
> >> > -
> >> > /* Define sysctl names first */
> >> >
> >> > /* Top-level names: */
> >> [snip]
> >>
> >> The uapi header change does not make sense. The entire point of the
> >> header is to allow userspace programs to be able to call sys_sysctl.
> >> It either needs to all stay or all go.
> >>
> >> As the concern with the uapi header is about userspace programs being
> >> able to compile please leave the header for now.
> >>
> >> We should leave auditing userspace and seeing if userspace code will
> >> still compile if we remove this header for a separate patch. The
> >> concerns and justifications for the uapi header are completely different
> >> then for the removing the sys_sysctl implementation.
> >>
> >> Otherwise
> >> Acked-by: "Eric W. Biederman" <ebiederm@xmission.com>
> >
> > The UAPI header should be kept because it's defining an API not just
> > for the kernel the headers are supplied with, but for all past
> > kernels. In particular programs needing a failsafe CSPRNG source that
> > works on old kernels may (do) use this as a fallback only if modern
> > syscalls are missing. Removing the syscall is no problem since it
> > won't be used, but if you remove the types/macros from the UAPI
> > headers, they'll have to copy that into their own sources.
>
> May we assume you know of a least one piece of userspace that will fail
> to compile if this header file is removed?
I know at least one piece of software is using SYS_sysctl for a
fallback CSPRNG source. I'm not 100% sure that they're using the
kernel headers; they might have copied it already. I'm also not sure
how many there are.
Regardless, I think the principle stands. There's no need to remove
definitions that are essentially maintenance-free now that the
interface is no longer available in new kernels, and doing so
contributes to the myth that you're supposed to use kernel headers
matching runtime kernel rather than it always being safe to use latest
headers.
Rich
^ permalink raw reply
* Re: [PATCH v2] All arch: remove system call sys_sysctl
From: Eric W. Biederman @ 2020-06-11 17:01 UTC (permalink / raw)
To: Rich Felker
Cc: linux-sh, catalin.marinas, paulus, ak, paulburton, geert,
mattst88, brgerst, acme, cyphar, viro, luto, tglx, surenb, rth,
young.liuyang, linux-parisc, rdunlap, linux-kernel, mcgrof,
linux-fsdevel, akpm, mark.rutland, linux-ia64, linux-xtensa,
jongk, linux, James.Bottomley, jcmvbkbc, linux-s390, ysato,
deller, yzaikin, Xiaoming Ni, mszeredi, gor, linux-alpha,
linux-m68k, linux-arm-kernel, chris, tony.luck, linux-api,
zhouyanjie, minchan, sargun, alexander.shishkin, heiko.carstens,
alex.huangjianhui, will, krzk, borntraeger, vbabka, samitolvanen,
flameeyes, ravi.bangoria, elver, keescook, arnd, bp, christian,
tsbogend, jiri, martin.petersen, yamada.masahiro, oleg,
sudeep.holla, olof, shawnguo, davem, bauerman, fenghua.yu, peterz,
dhowells, hpa, sparclinux, jolsa, svens, x86, linux, mingo,
naveen.n.rao, paulmck, sfr, npiggin, namhyung, dvyukov, axboe,
monstr, haolee.swjtu, linux-mips, ink, linuxppc-dev
In-Reply-To: <20200611163902.GN1079@brightrain.aerifal.cx>
Rich Felker <dalias@libc.org> writes:
> On Thu, Jun 11, 2020 at 06:43:00AM -0500, Eric W. Biederman wrote:
>> Xiaoming Ni <nixiaoming@huawei.com> writes:
>>
>> > Since the commit 61a47c1ad3a4dc ("sysctl: Remove the sysctl system call"),
>> > sys_sysctl is actually unavailable: any input can only return an error.
>> >
>> > We have been warning about people using the sysctl system call for years
>> > and believe there are no more users. Even if there are users of this
>> > interface if they have not complained or fixed their code by now they
>> > probably are not going to, so there is no point in warning them any
>> > longer.
>> >
>> > So completely remove sys_sysctl on all architectures.
>>
>>
>>
>> >
>> > Signed-off-by: Xiaoming Ni <nixiaoming@huawei.com>
>> >
>> > changes in v2:
>> > According to Kees Cook's suggestion, completely remove sys_sysctl on all arch
>> > According to Eric W. Biederman's suggestion, update the commit log
>> >
>> > V1: https://lore.kernel.org/lkml/1591683605-8585-1-git-send-email-nixiaoming@huawei.com/
>> > Delete the code of sys_sysctl and return -ENOSYS directly at the function entry
>> > ---
>> > include/uapi/linux/sysctl.h | 15 --
>> [snip]
>>
>> > diff --git a/include/uapi/linux/sysctl.h b/include/uapi/linux/sysctl.h
>> > index 27c1ed2..84b44c3 100644
>> > --- a/include/uapi/linux/sysctl.h
>> > +++ b/include/uapi/linux/sysctl.h
>> > @@ -27,21 +27,6 @@
>> > #include <linux/types.h>
>> > #include <linux/compiler.h>
>> >
>> > -#define CTL_MAXNAME 10 /* how many path components do we allow in a
>> > - call to sysctl? In other words, what is
>> > - the largest acceptable value for the nlen
>> > - member of a struct __sysctl_args to have? */
>> > -
>> > -struct __sysctl_args {
>> > - int __user *name;
>> > - int nlen;
>> > - void __user *oldval;
>> > - size_t __user *oldlenp;
>> > - void __user *newval;
>> > - size_t newlen;
>> > - unsigned long __unused[4];
>> > -};
>> > -
>> > /* Define sysctl names first */
>> >
>> > /* Top-level names: */
>> [snip]
>>
>> The uapi header change does not make sense. The entire point of the
>> header is to allow userspace programs to be able to call sys_sysctl.
>> It either needs to all stay or all go.
>>
>> As the concern with the uapi header is about userspace programs being
>> able to compile please leave the header for now.
>>
>> We should leave auditing userspace and seeing if userspace code will
>> still compile if we remove this header for a separate patch. The
>> concerns and justifications for the uapi header are completely different
>> then for the removing the sys_sysctl implementation.
>>
>> Otherwise
>> Acked-by: "Eric W. Biederman" <ebiederm@xmission.com>
>
> The UAPI header should be kept because it's defining an API not just
> for the kernel the headers are supplied with, but for all past
> kernels. In particular programs needing a failsafe CSPRNG source that
> works on old kernels may (do) use this as a fallback only if modern
> syscalls are missing. Removing the syscall is no problem since it
> won't be used, but if you remove the types/macros from the UAPI
> headers, they'll have to copy that into their own sources.
May we assume you know of a least one piece of userspace that will fail
to compile if this header file is removed?
Eric
^ permalink raw reply
* Re: [PATCH v2] All arch: remove system call sys_sysctl
From: Eric W. Biederman @ 2020-06-11 18:23 UTC (permalink / raw)
To: Rich Felker
Cc: linux-sh, catalin.marinas, paulus, ak, paulburton, geert,
mattst88, brgerst, acme, cyphar, viro, luto, tglx, surenb, rth,
young.liuyang, linux-parisc, rdunlap, linux-kernel, mcgrof,
linux-fsdevel, akpm, mark.rutland, linux-ia64, linux-xtensa,
jongk, linux, James.Bottomley, jcmvbkbc, linux-s390, ysato,
deller, yzaikin, Xiaoming Ni, mszeredi, gor, linux-alpha,
linux-m68k, linux-arm-kernel, chris, tony.luck, linux-api,
zhouyanjie, minchan, sargun, alexander.shishkin, heiko.carstens,
alex.huangjianhui, will, krzk, borntraeger, vbabka, samitolvanen,
flameeyes, ravi.bangoria, elver, keescook, arnd, bp, christian,
tsbogend, jiri, martin.petersen, yamada.masahiro, oleg,
sudeep.holla, olof, shawnguo, davem, bauerman, fenghua.yu, peterz,
dhowells, hpa, sparclinux, jolsa, svens, x86, linux, mingo,
naveen.n.rao, paulmck, sfr, npiggin, namhyung, dvyukov, axboe,
monstr, haolee.swjtu, linux-mips, ink, linuxppc-dev
In-Reply-To: <20200611172028.GO1079@brightrain.aerifal.cx>
Rich Felker <dalias@libc.org> writes:
> On Thu, Jun 11, 2020 at 12:01:11PM -0500, Eric W. Biederman wrote:
>> Rich Felker <dalias@libc.org> writes:
>>
>> > On Thu, Jun 11, 2020 at 06:43:00AM -0500, Eric W. Biederman wrote:
>> >> Xiaoming Ni <nixiaoming@huawei.com> writes:
>> >>
>> >> > Since the commit 61a47c1ad3a4dc ("sysctl: Remove the sysctl system call"),
>> >> > sys_sysctl is actually unavailable: any input can only return an error.
>> >> >
>> >> > We have been warning about people using the sysctl system call for years
>> >> > and believe there are no more users. Even if there are users of this
>> >> > interface if they have not complained or fixed their code by now they
>> >> > probably are not going to, so there is no point in warning them any
>> >> > longer.
>> >> >
>> >> > So completely remove sys_sysctl on all architectures.
>> >>
>> >>
>> >>
>> >> >
>> >> > Signed-off-by: Xiaoming Ni <nixiaoming@huawei.com>
>> >> >
>> >> > changes in v2:
>> >> > According to Kees Cook's suggestion, completely remove sys_sysctl on all arch
>> >> > According to Eric W. Biederman's suggestion, update the commit log
>> >> >
>> >> > V1: https://lore.kernel.org/lkml/1591683605-8585-1-git-send-email-nixiaoming@huawei.com/
>> >> > Delete the code of sys_sysctl and return -ENOSYS directly at the function entry
>> >> > ---
>> >> > include/uapi/linux/sysctl.h | 15 --
>> >> [snip]
>> >>
>> >> > diff --git a/include/uapi/linux/sysctl.h b/include/uapi/linux/sysctl.h
>> >> > index 27c1ed2..84b44c3 100644
>> >> > --- a/include/uapi/linux/sysctl.h
>> >> > +++ b/include/uapi/linux/sysctl.h
>> >> > @@ -27,21 +27,6 @@
>> >> > #include <linux/types.h>
>> >> > #include <linux/compiler.h>
>> >> >
>> >> > -#define CTL_MAXNAME 10 /* how many path components do we allow in a
>> >> > - call to sysctl? In other words, what is
>> >> > - the largest acceptable value for the nlen
>> >> > - member of a struct __sysctl_args to have? */
>> >> > -
>> >> > -struct __sysctl_args {
>> >> > - int __user *name;
>> >> > - int nlen;
>> >> > - void __user *oldval;
>> >> > - size_t __user *oldlenp;
>> >> > - void __user *newval;
>> >> > - size_t newlen;
>> >> > - unsigned long __unused[4];
>> >> > -};
>> >> > -
>> >> > /* Define sysctl names first */
>> >> >
>> >> > /* Top-level names: */
>> >> [snip]
>> >>
>> >> The uapi header change does not make sense. The entire point of the
>> >> header is to allow userspace programs to be able to call sys_sysctl.
>> >> It either needs to all stay or all go.
>> >>
>> >> As the concern with the uapi header is about userspace programs being
>> >> able to compile please leave the header for now.
>> >>
>> >> We should leave auditing userspace and seeing if userspace code will
>> >> still compile if we remove this header for a separate patch. The
>> >> concerns and justifications for the uapi header are completely different
>> >> then for the removing the sys_sysctl implementation.
>> >>
>> >> Otherwise
>> >> Acked-by: "Eric W. Biederman" <ebiederm@xmission.com>
>> >
>> > The UAPI header should be kept because it's defining an API not just
>> > for the kernel the headers are supplied with, but for all past
>> > kernels. In particular programs needing a failsafe CSPRNG source that
>> > works on old kernels may (do) use this as a fallback only if modern
>> > syscalls are missing. Removing the syscall is no problem since it
>> > won't be used, but if you remove the types/macros from the UAPI
>> > headers, they'll have to copy that into their own sources.
>>
>> May we assume you know of a least one piece of userspace that will fail
>> to compile if this header file is removed?
>
> I know at least one piece of software is using SYS_sysctl for a
> fallback CSPRNG source. I'm not 100% sure that they're using the
> kernel headers; they might have copied it already. I'm also not sure
> how many there are.
>
> Regardless, I think the principle stands. There's no need to remove
> definitions that are essentially maintenance-free now that the
> interface is no longer available in new kernels, and doing so
> contributes to the myth that you're supposed to use kernel headers
> matching runtime kernel rather than it always being safe to use latest
> headers.
If there is no one using the definitions removing them saves people
having to remember what they are there for.
The big rule is don't break userspace. The goal is to allow people to
upgrade their kernel without needing to worry about userspace breaking,
and to be able to downgrade to the extent possible to help in tracking
bugs.
Not being able to compile userspace seems like a pretty clear cut case.
Although there are some fuzzy edges given the history of the kernel
headers. Things like your libc requiring kernel headers to be processed
before they can be used. I think there are still some kernel headers
that have that restriction when used with glibc as glibc uses different
sizes for types like dev_t.
The bottom line is we can't do it casually so that any work in the
direction of removing from or deleting uapi headers needs to be it's own
separate patch.
Given how much effort it can be to show that userspace is not using
something I don't expect us to be mucking with the uapi headers any time
soon.
Eric
^ permalink raw reply
* Re: [PATCH v2] powerpc: Remove inaccessible CMDLINE default
From: Chris Packham @ 2020-06-11 21:14 UTC (permalink / raw)
To: Christophe Leroy, mpe@ellerman.id.au, benh@kernel.crashing.org,
paulus@samba.org, christophe.leroy@c-s.fr
Cc: linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org
In-Reply-To: <34bb20ad-8522-6071-7a36-9f615204561f@csgroup.eu>
On 11/06/20 5:46 pm, Christophe Leroy wrote:
>
>
> Le 11/06/2020 à 05:41, Chris Packham a écrit :
>> Since commit cbe46bd4f510 ("powerpc: remove CONFIG_CMDLINE #ifdef mess")
>> CONFIG_CMDLINE has always had a value regardless of CONFIG_CMDLINE_BOOL.
>>
>> For example:
>>
>> $ make ARCH=powerpc defconfig
>> $ cat .config
>> # CONFIG_CMDLINE_BOOL is not set
>> CONFIG_CMDLINE=""
>>
>> When enabling CONFIG_CMDLINE_BOOL this value is kept making the 'default
>> "..." if CONFIG_CMDLINE_BOOL' ineffective.
>>
>> $ ./scripts/config --enable CONFIG_CMDLINE_BOOL
>> $ cat .config
>> CONFIG_CMDLINE_BOOL=y
>> CONFIG_CMDLINE=""
>>
>> Remove CONFIG_CMDLINE_BOOL and the inaccessible default.
>
> You also have to remove all CONFIG_CMDLINE_BOOL from the defconfigs
OK. I'll do so as a follow-up patch and send a v3.
>
> Christophe
>
>>
>> Signed-off-by: Chris Packham <chris.packham@alliedtelesis.co.nz>
>> Reviewed-by: Christophe Leroy <christophe.leroy@c-s.fr>
>> ---
>> It took me a while to get round to sending a v2, for a refresher v1
>> can be found here:
>>
>> http://patchwork.ozlabs.org/project/linuxppc-dev/patch/20190802050232.22978-1-chris.packham@alliedtelesis.co.nz/
>>
>>
>> Changes in v2:
>> - Rebase on top of Linus's tree
>> - Fix some typos in commit message
>> - Add review from Christophe
>> - Remove CONFIG_CMDLINE_BOOL
>>
>> arch/powerpc/Kconfig | 6 +-----
>> 1 file changed, 1 insertion(+), 5 deletions(-)
>>
>> diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
>> index 9fa23eb320ff..51abc59c3334 100644
>> --- a/arch/powerpc/Kconfig
>> +++ b/arch/powerpc/Kconfig
>> @@ -859,12 +859,8 @@ config PPC_DENORMALISATION
>> Add support for handling denormalisation of single precision
>> values. Useful for bare metal only. If unsure say Y here.
>> -config CMDLINE_BOOL
>> - bool "Default bootloader kernel arguments"
>> -
>> config CMDLINE
>> - string "Initial kernel command string" if CMDLINE_BOOL
>> - default "console=ttyS0,9600 console=tty0 root=/dev/sda2" if
>> CMDLINE_BOOL
>> + string "Initial kernel command string"
>> default ""
>> help
>> On some platforms, there is currently no way for the boot
>> loader to
>>
^ permalink raw reply
* Re: [PATCH v5 1/4] riscv: Move kernel mapping to vmalloc zone
From: Atish Patra @ 2020-06-11 21:34 UTC (permalink / raw)
To: Alexandre Ghiti
Cc: Albert Ou, Anup Patel, linux-kernel@vger.kernel.org List,
Atish Patra, Paul Mackerras, Zong Li, Paul Walmsley,
Palmer Dabbelt, linux-riscv, linuxppc-dev
In-Reply-To: <20200607075949.665-2-alex@ghiti.fr>
On Sun, Jun 7, 2020 at 1:01 AM Alexandre Ghiti <alex@ghiti.fr> wrote:
>
> This is a preparatory patch for relocatable kernel.
>
> The kernel used to be linked at PAGE_OFFSET address and used to be loaded
> physically at the beginning of the main memory. Therefore, we could use
> the linear mapping for the kernel mapping.
>
> But the relocated kernel base address will be different from PAGE_OFFSET
> and since in the linear mapping, two different virtual addresses cannot
> point to the same physical address, the kernel mapping needs to lie outside
> the linear mapping.
>
> In addition, because modules and BPF must be close to the kernel (inside
> +-2GB window), the kernel is placed at the end of the vmalloc zone minus
> 2GB, which leaves room for modules and BPF. The kernel could not be
> placed at the beginning of the vmalloc zone since other vmalloc
> allocations from the kernel could get all the +-2GB window around the
> kernel which would prevent new modules and BPF programs to be loaded.
>
> Signed-off-by: Alexandre Ghiti <alex@ghiti.fr>
> Reviewed-by: Zong Li <zong.li@sifive.com>
> ---
> arch/riscv/boot/loader.lds.S | 3 +-
> arch/riscv/include/asm/page.h | 10 +++++-
> arch/riscv/include/asm/pgtable.h | 38 ++++++++++++++-------
> arch/riscv/kernel/head.S | 3 +-
> arch/riscv/kernel/module.c | 4 +--
> arch/riscv/kernel/vmlinux.lds.S | 3 +-
> arch/riscv/mm/init.c | 58 +++++++++++++++++++++++++-------
> arch/riscv/mm/physaddr.c | 2 +-
> 8 files changed, 88 insertions(+), 33 deletions(-)
>
> diff --git a/arch/riscv/boot/loader.lds.S b/arch/riscv/boot/loader.lds.S
> index 47a5003c2e28..62d94696a19c 100644
> --- a/arch/riscv/boot/loader.lds.S
> +++ b/arch/riscv/boot/loader.lds.S
> @@ -1,13 +1,14 @@
> /* SPDX-License-Identifier: GPL-2.0 */
>
> #include <asm/page.h>
> +#include <asm/pgtable.h>
>
> OUTPUT_ARCH(riscv)
> ENTRY(_start)
>
> SECTIONS
> {
> - . = PAGE_OFFSET;
> + . = KERNEL_LINK_ADDR;
>
> .payload : {
> *(.payload)
> diff --git a/arch/riscv/include/asm/page.h b/arch/riscv/include/asm/page.h
> index 2d50f76efe48..48bb09b6a9b7 100644
> --- a/arch/riscv/include/asm/page.h
> +++ b/arch/riscv/include/asm/page.h
> @@ -90,18 +90,26 @@ typedef struct page *pgtable_t;
>
> #ifdef CONFIG_MMU
> extern unsigned long va_pa_offset;
> +extern unsigned long va_kernel_pa_offset;
> extern unsigned long pfn_base;
> #define ARCH_PFN_OFFSET (pfn_base)
> #else
> #define va_pa_offset 0
> +#define va_kernel_pa_offset 0
> #define ARCH_PFN_OFFSET (PAGE_OFFSET >> PAGE_SHIFT)
> #endif /* CONFIG_MMU */
>
> extern unsigned long max_low_pfn;
> extern unsigned long min_low_pfn;
> +extern unsigned long kernel_virt_addr;
>
> #define __pa_to_va_nodebug(x) ((void *)((unsigned long) (x) + va_pa_offset))
> -#define __va_to_pa_nodebug(x) ((unsigned long)(x) - va_pa_offset)
> +#define linear_mapping_va_to_pa(x) ((unsigned long)(x) - va_pa_offset)
> +#define kernel_mapping_va_to_pa(x) \
> + ((unsigned long)(x) - va_kernel_pa_offset)
> +#define __va_to_pa_nodebug(x) \
> + (((x) >= PAGE_OFFSET) ? \
> + linear_mapping_va_to_pa(x) : kernel_mapping_va_to_pa(x))
>
> #ifdef CONFIG_DEBUG_VIRTUAL
> extern phys_addr_t __virt_to_phys(unsigned long x);
> diff --git a/arch/riscv/include/asm/pgtable.h b/arch/riscv/include/asm/pgtable.h
> index 35b60035b6b0..94ef3b49dfb6 100644
> --- a/arch/riscv/include/asm/pgtable.h
> +++ b/arch/riscv/include/asm/pgtable.h
> @@ -11,23 +11,29 @@
>
> #include <asm/pgtable-bits.h>
>
> -#ifndef __ASSEMBLY__
> -
> -/* Page Upper Directory not used in RISC-V */
> -#include <asm-generic/pgtable-nopud.h>
> -#include <asm/page.h>
> -#include <asm/tlbflush.h>
> -#include <linux/mm_types.h>
> -
> -#ifdef CONFIG_MMU
> +#ifndef CONFIG_MMU
> +#define KERNEL_VIRT_ADDR PAGE_OFFSET
> +#define KERNEL_LINK_ADDR PAGE_OFFSET
> +#else
> +/*
> + * Leave 2GB for modules and BPF that must lie within a 2GB range around
> + * the kernel.
> + */
> +#define KERNEL_VIRT_ADDR (VMALLOC_END - SZ_2G + 1)
> +#define KERNEL_LINK_ADDR KERNEL_VIRT_ADDR
>
> #define VMALLOC_SIZE (KERN_VIRT_SIZE >> 1)
> #define VMALLOC_END (PAGE_OFFSET - 1)
> #define VMALLOC_START (PAGE_OFFSET - VMALLOC_SIZE)
>
> #define BPF_JIT_REGION_SIZE (SZ_128M)
> -#define BPF_JIT_REGION_START (PAGE_OFFSET - BPF_JIT_REGION_SIZE)
> -#define BPF_JIT_REGION_END (VMALLOC_END)
> +#define BPF_JIT_REGION_START PFN_ALIGN((unsigned long)&_end)
> +#define BPF_JIT_REGION_END (BPF_JIT_REGION_START + BPF_JIT_REGION_SIZE)
> +
As these mappings have changed a few times in recent months including
this one, I think it would be
better to have virtual memory layout documentation in RISC-V similar
to other architectures.
If you can include the page table layout for 3/4 level page tables in
the same document, that would be really helpful.
> +#ifdef CONFIG_64BIT
> +#define VMALLOC_MODULE_START BPF_JIT_REGION_END
> +#define VMALLOC_MODULE_END (((unsigned long)&_start & PAGE_MASK) + SZ_2G)
> +#endif
>
> /*
> * Roughly size the vmemmap space to be large enough to fit enough
> @@ -57,9 +63,16 @@
> #define FIXADDR_SIZE PGDIR_SIZE
> #endif
> #define FIXADDR_START (FIXADDR_TOP - FIXADDR_SIZE)
> -
> #endif
>
> +#ifndef __ASSEMBLY__
> +
> +/* Page Upper Directory not used in RISC-V */
> +#include <asm-generic/pgtable-nopud.h>
> +#include <asm/page.h>
> +#include <asm/tlbflush.h>
> +#include <linux/mm_types.h>
> +
> #ifdef CONFIG_64BIT
> #include <asm/pgtable-64.h>
> #else
> @@ -483,6 +496,7 @@ static inline void __kernel_map_pages(struct page *page, int numpages, int enabl
>
> #define kern_addr_valid(addr) (1) /* FIXME */
>
> +extern char _start[];
> extern void *dtb_early_va;
> void setup_bootmem(void);
> void paging_init(void);
> diff --git a/arch/riscv/kernel/head.S b/arch/riscv/kernel/head.S
> index 98a406474e7d..8f5bb7731327 100644
> --- a/arch/riscv/kernel/head.S
> +++ b/arch/riscv/kernel/head.S
> @@ -49,7 +49,8 @@ ENTRY(_start)
> #ifdef CONFIG_MMU
> relocate:
> /* Relocate return address */
> - li a1, PAGE_OFFSET
> + la a1, kernel_virt_addr
> + REG_L a1, 0(a1)
> la a2, _start
> sub a1, a1, a2
> add ra, ra, a1
> diff --git a/arch/riscv/kernel/module.c b/arch/riscv/kernel/module.c
> index 8bbe5dbe1341..1a8fbe05accf 100644
> --- a/arch/riscv/kernel/module.c
> +++ b/arch/riscv/kernel/module.c
> @@ -392,12 +392,10 @@ int apply_relocate_add(Elf_Shdr *sechdrs, const char *strtab,
> }
>
> #if defined(CONFIG_MMU) && defined(CONFIG_64BIT)
> -#define VMALLOC_MODULE_START \
> - max(PFN_ALIGN((unsigned long)&_end - SZ_2G), VMALLOC_START)
> void *module_alloc(unsigned long size)
> {
> return __vmalloc_node_range(size, 1, VMALLOC_MODULE_START,
> - VMALLOC_END, GFP_KERNEL,
> + VMALLOC_MODULE_END, GFP_KERNEL,
> PAGE_KERNEL_EXEC, 0, NUMA_NO_NODE,
> __builtin_return_address(0));
> }
> diff --git a/arch/riscv/kernel/vmlinux.lds.S b/arch/riscv/kernel/vmlinux.lds.S
> index 0339b6bbe11a..a9abde62909f 100644
> --- a/arch/riscv/kernel/vmlinux.lds.S
> +++ b/arch/riscv/kernel/vmlinux.lds.S
> @@ -4,7 +4,8 @@
> * Copyright (C) 2017 SiFive
> */
>
> -#define LOAD_OFFSET PAGE_OFFSET
> +#include <asm/pgtable.h>
> +#define LOAD_OFFSET KERNEL_LINK_ADDR
> #include <asm/vmlinux.lds.h>
> #include <asm/page.h>
> #include <asm/cache.h>
> diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c
> index 736de6c8739f..71da78914645 100644
> --- a/arch/riscv/mm/init.c
> +++ b/arch/riscv/mm/init.c
> @@ -22,6 +22,9 @@
>
> #include "../kernel/head.h"
>
> +unsigned long kernel_virt_addr = KERNEL_VIRT_ADDR;
> +EXPORT_SYMBOL(kernel_virt_addr);
> +
> unsigned long empty_zero_page[PAGE_SIZE / sizeof(unsigned long)]
> __page_aligned_bss;
> EXPORT_SYMBOL(empty_zero_page);
> @@ -178,8 +181,12 @@ void __init setup_bootmem(void)
> }
>
> #ifdef CONFIG_MMU
> +/* Offset between linear mapping virtual address and kernel load address */
> unsigned long va_pa_offset;
> EXPORT_SYMBOL(va_pa_offset);
> +/* Offset between kernel mapping virtual address and kernel load address */
> +unsigned long va_kernel_pa_offset;
> +EXPORT_SYMBOL(va_kernel_pa_offset);
> unsigned long pfn_base;
> EXPORT_SYMBOL(pfn_base);
>
> @@ -271,7 +278,7 @@ static phys_addr_t __init alloc_pmd(uintptr_t va)
> if (mmu_enabled)
> return memblock_phys_alloc(PAGE_SIZE, PAGE_SIZE);
>
> - pmd_num = (va - PAGE_OFFSET) >> PGDIR_SHIFT;
> + pmd_num = (va - kernel_virt_addr) >> PGDIR_SHIFT;
> BUG_ON(pmd_num >= NUM_EARLY_PMDS);
> return (uintptr_t)&early_pmd[pmd_num * PTRS_PER_PMD];
> }
> @@ -372,14 +379,30 @@ static uintptr_t __init best_map_size(phys_addr_t base, phys_addr_t size)
> #error "setup_vm() is called from head.S before relocate so it should not use absolute addressing."
> #endif
>
> +static uintptr_t load_pa, load_sz;
> +
> +static void __init create_kernel_page_table(pgd_t *pgdir, uintptr_t map_size)
> +{
> + uintptr_t va, end_va;
> +
> + end_va = kernel_virt_addr + load_sz;
> + for (va = kernel_virt_addr; va < end_va; va += map_size)
> + create_pgd_mapping(pgdir, va,
> + load_pa + (va - kernel_virt_addr),
> + map_size, PAGE_KERNEL_EXEC);
> +}
> +
> asmlinkage void __init setup_vm(uintptr_t dtb_pa)
> {
> uintptr_t va, end_va;
> - uintptr_t load_pa = (uintptr_t)(&_start);
> - uintptr_t load_sz = (uintptr_t)(&_end) - load_pa;
> uintptr_t map_size = best_map_size(load_pa, MAX_EARLY_MAPPING_SIZE);
>
> + load_pa = (uintptr_t)(&_start);
> + load_sz = (uintptr_t)(&_end) - load_pa;
> +
> va_pa_offset = PAGE_OFFSET - load_pa;
> + va_kernel_pa_offset = kernel_virt_addr - load_pa;
> +
> pfn_base = PFN_DOWN(load_pa);
>
> /*
> @@ -402,26 +425,22 @@ asmlinkage void __init setup_vm(uintptr_t dtb_pa)
> create_pmd_mapping(fixmap_pmd, FIXADDR_START,
> (uintptr_t)fixmap_pte, PMD_SIZE, PAGE_TABLE);
> /* Setup trampoline PGD and PMD */
> - create_pgd_mapping(trampoline_pg_dir, PAGE_OFFSET,
> + create_pgd_mapping(trampoline_pg_dir, kernel_virt_addr,
> (uintptr_t)trampoline_pmd, PGDIR_SIZE, PAGE_TABLE);
> - create_pmd_mapping(trampoline_pmd, PAGE_OFFSET,
> + create_pmd_mapping(trampoline_pmd, kernel_virt_addr,
> load_pa, PMD_SIZE, PAGE_KERNEL_EXEC);
> #else
> /* Setup trampoline PGD */
> - create_pgd_mapping(trampoline_pg_dir, PAGE_OFFSET,
> + create_pgd_mapping(trampoline_pg_dir, kernel_virt_addr,
> load_pa, PGDIR_SIZE, PAGE_KERNEL_EXEC);
> #endif
>
> /*
> - * Setup early PGD covering entire kernel which will allows
> + * Setup early PGD covering entire kernel which will allow
> * us to reach paging_init(). We map all memory banks later
> * in setup_vm_final() below.
> */
> - end_va = PAGE_OFFSET + load_sz;
> - for (va = PAGE_OFFSET; va < end_va; va += map_size)
> - create_pgd_mapping(early_pg_dir, va,
> - load_pa + (va - PAGE_OFFSET),
> - map_size, PAGE_KERNEL_EXEC);
> + create_kernel_page_table(early_pg_dir, map_size);
>
> /* Create fixed mapping for early FDT parsing */
> end_va = __fix_to_virt(FIX_FDT) + FIX_FDT_SIZE;
> @@ -441,6 +460,7 @@ static void __init setup_vm_final(void)
> uintptr_t va, map_size;
> phys_addr_t pa, start, end;
> struct memblock_region *reg;
> + static struct vm_struct vm_kernel = { 0 };
>
> /* Set mmu_enabled flag */
> mmu_enabled = true;
> @@ -467,10 +487,22 @@ static void __init setup_vm_final(void)
> for (pa = start; pa < end; pa += map_size) {
> va = (uintptr_t)__va(pa);
> create_pgd_mapping(swapper_pg_dir, va, pa,
> - map_size, PAGE_KERNEL_EXEC);
> + map_size, PAGE_KERNEL);
> }
> }
>
> + /* Map the kernel */
> + create_kernel_page_table(swapper_pg_dir, PMD_SIZE);
> +
> + /* Reserve the vmalloc area occupied by the kernel */
> + vm_kernel.addr = (void *)kernel_virt_addr;
> + vm_kernel.phys_addr = load_pa;
> + vm_kernel.size = (load_sz + PMD_SIZE - 1) & ~(PMD_SIZE - 1);
> + vm_kernel.flags = VM_MAP | VM_NO_GUARD;
> + vm_kernel.caller = __builtin_return_address(0);
> +
> + vm_area_add_early(&vm_kernel);
> +
> /* Clear fixmap PTE and PMD mappings */
> clear_fixmap(FIX_PTE);
> clear_fixmap(FIX_PMD);
> diff --git a/arch/riscv/mm/physaddr.c b/arch/riscv/mm/physaddr.c
> index e8e4dcd39fed..35703d5ef5fd 100644
> --- a/arch/riscv/mm/physaddr.c
> +++ b/arch/riscv/mm/physaddr.c
> @@ -23,7 +23,7 @@ EXPORT_SYMBOL(__virt_to_phys);
>
> phys_addr_t __phys_addr_symbol(unsigned long x)
> {
> - unsigned long kernel_start = (unsigned long)PAGE_OFFSET;
> + unsigned long kernel_start = (unsigned long)kernel_virt_addr;
> unsigned long kernel_end = (unsigned long)_end;
>
> /*
> --
> 2.20.1
>
>
--
Regards,
Atish
^ permalink raw reply
* (no subject)
From: ndesaulniers @ 2020-06-11 22:38 UTC (permalink / raw)
To: patch-notifications, christophe.leroy, segher, benh, paulus,
npiggin, linuxppc-dev, linux-kernel, clang-built-linux
Date: Thu, 11 Jun 2020 15:38:38 -0700
From: Nick Desaulniers <ndesaulniers@google.com>
To: Michael Ellerman <patch-notifications@ellerman.id.au>,
christophe.leroy@c-s.fr, segher@kernel.crashing.org
Cc: Christophe Leroy <christophe.leroy@c-s.fr>,
Benjamin Herrenschmidt <benh@kernel.crashing.org>,
Paul Mackerras <paulus@samba.org>, npiggin@gmail.com,
segher@kernel.crashing.org, linuxppc-dev@lists.ozlabs.org,
linux-kernel@vger.kernel.org, clang-built-linux@googlegroups.com
Subject: Re: [PATCH v4 1/2] powerpc/uaccess: Implement unsafe_put_user()
using 'asm goto'
Message-ID: <20200611223838.GA60089@google.com>
References:
<23e680624680a9a5405f4b88740d2596d4b17c26.1587143308.git.christophe.leroy@c-s.fr>
<49YBKY13Szz9sT4@ozlabs.org>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <49YBKY13Szz9sT4@ozlabs.org>
On Fri, May 29, 2020 at 02:24:16PM +1000, Michael Ellerman wrote:
> On Fri, 2020-04-17 at 17:08:51 UTC, Christophe Leroy wrote:
> > unsafe_put_user() is designed to take benefit of 'asm goto'.
> >
> > Instead of using the standard __put_user() approach and branch
> > based on the returned error, use 'asm goto' and make the
> > exception code branch directly to the error label. There is
> > no code anymore in the fixup section.
> >
> > This change significantly simplifies functions using
> > unsafe_put_user()
> ...
> >
> > Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
> > Reviewed-by: Segher Boessenkool <segher@kernel.crashing.org>
> Applied to powerpc topic/uaccess-ppc, thanks.
> https://git.kernel.org/powerpc/c/334710b1496af8a0960e70121f850e209c20958f
> cheers
Hello! It seems this patch broke our ppc32 builds, and we had to
disable them [0]. :(
From what I can tell, though Michael mentioned this was merged on May
29, but our CI of -next was green for ppc32 until June 4, then mainline
went red June 6. So this patch only got 2 days of soak time before the
merge window opened.
A general issue with the -next workflow seems to be that patches get
different amounts of soak time. For higher risk patches like this one,
can I please ask that they be help back a release if close to the merge
window?
Segher, Cristophe, I suspect Clang is missing support for the %L and %U
output templates [1]. I've implemented support for some of these before
in Clang via the documentation at [2], but these seem to be machine
specific? Can you please point me to documentation/unit tests/source for
these so that I can figure out what they should be doing, and look into
implementing them in Clang?
(Apologies for the tone off this email; I had typed up a nice fuller
report with links, but it seemed that mutt wrote out an empty postponed
file, and I kind of just want to put my laptop in the garbage right now.
I suspect our internal SMTP tool will also mess up some headers, but
lets see (Also, too lazy+angry right now to solve).)
[0] https://github.com/ClangBuiltLinux/continuous-integration/pull/279
[1] https://bugs.llvm.org/show_bug.cgi?id=46186
[2]
https://gcc.gnu.org/onlinedocs/gccint/Output-Template.html#Output-Template
^ permalink raw reply
* [PATCH v3 0/2] powerpc: CMDLINE config cleanup
From: Chris Packham @ 2020-06-11 22:42 UTC (permalink / raw)
To: mpe, benh, paulus, christophe.leroy
Cc: Chris Packham, linuxppc-dev, linux-kernel
This series cleans up the config options related to the boot command line.
Chris Packham (2):
powerpc: Remove inaccessible CMDLINE default
powerpc: configs: remove CMDLINE_BOOL
arch/powerpc/Kconfig | 6 +-----
arch/powerpc/configs/44x/akebono_defconfig | 2 --
arch/powerpc/configs/44x/arches_defconfig | 2 --
arch/powerpc/configs/44x/bamboo_defconfig | 2 --
arch/powerpc/configs/44x/bluestone_defconfig | 2 --
arch/powerpc/configs/44x/canyonlands_defconfig | 2 --
arch/powerpc/configs/44x/currituck_defconfig | 2 --
arch/powerpc/configs/44x/eiger_defconfig | 2 --
arch/powerpc/configs/44x/fsp2_defconfig | 1 -
arch/powerpc/configs/44x/icon_defconfig | 2 --
arch/powerpc/configs/44x/iss476-smp_defconfig | 1 -
arch/powerpc/configs/44x/katmai_defconfig | 2 --
arch/powerpc/configs/44x/rainier_defconfig | 2 --
arch/powerpc/configs/44x/redwood_defconfig | 2 --
arch/powerpc/configs/44x/sam440ep_defconfig | 2 --
arch/powerpc/configs/44x/sequoia_defconfig | 2 --
arch/powerpc/configs/44x/taishan_defconfig | 2 --
arch/powerpc/configs/44x/warp_defconfig | 1 -
arch/powerpc/configs/holly_defconfig | 1 -
arch/powerpc/configs/mvme5100_defconfig | 3 +--
arch/powerpc/configs/ps3_defconfig | 2 --
arch/powerpc/configs/skiroot_defconfig | 1 -
arch/powerpc/configs/storcenter_defconfig | 1 -
23 files changed, 2 insertions(+), 43 deletions(-)
--
2.27.0
^ permalink raw reply
* [PATCH v3 1/2] powerpc: Remove inaccessible CMDLINE default
From: Chris Packham @ 2020-06-11 22:42 UTC (permalink / raw)
To: mpe, benh, paulus, christophe.leroy
Cc: Chris Packham, linuxppc-dev, linux-kernel
In-Reply-To: <20200611224220.25066-1-chris.packham@alliedtelesis.co.nz>
Since commit cbe46bd4f510 ("powerpc: remove CONFIG_CMDLINE #ifdef mess")
CONFIG_CMDLINE has always had a value regardless of CONFIG_CMDLINE_BOOL.
For example:
$ make ARCH=powerpc defconfig
$ cat .config
# CONFIG_CMDLINE_BOOL is not set
CONFIG_CMDLINE=""
When enabling CONFIG_CMDLINE_BOOL this value is kept making the 'default
"..." if CONFIG_CMDLINE_BOOL' ineffective.
$ ./scripts/config --enable CONFIG_CMDLINE_BOOL
$ cat .config
CONFIG_CMDLINE_BOOL=y
CONFIG_CMDLINE=""
Remove CONFIG_CMDLINE_BOOL and the inaccessible default.
Signed-off-by: Chris Packham <chris.packham@alliedtelesis.co.nz>
Reviewed-by: Christophe Leroy <christophe.leroy@c-s.fr>
---
Changes in v3:
- none
Changes in v2:
- Rebase on top of Linus's tree
- Fix some typos in commit message
- Add review from Christophe
- Remove CONFIG_CMDLINE_BOOL
arch/powerpc/Kconfig | 6 +-----
1 file changed, 1 insertion(+), 5 deletions(-)
diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index 9fa23eb320ff..51abc59c3334 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -859,12 +859,8 @@ config PPC_DENORMALISATION
Add support for handling denormalisation of single precision
values. Useful for bare metal only. If unsure say Y here.
-config CMDLINE_BOOL
- bool "Default bootloader kernel arguments"
-
config CMDLINE
- string "Initial kernel command string" if CMDLINE_BOOL
- default "console=ttyS0,9600 console=tty0 root=/dev/sda2" if CMDLINE_BOOL
+ string "Initial kernel command string"
default ""
help
On some platforms, there is currently no way for the boot loader to
--
2.27.0
^ permalink raw reply related
* [PATCH v3 2/2] powerpc: configs: remove CMDLINE_BOOL
From: Chris Packham @ 2020-06-11 22:42 UTC (permalink / raw)
To: mpe, benh, paulus, christophe.leroy
Cc: Chris Packham, linuxppc-dev, linux-kernel
In-Reply-To: <20200611224220.25066-1-chris.packham@alliedtelesis.co.nz>
Regenerate defconfigs to remove CONFIG_CMDLINE_BOOL and the default
CONFIG_CMDLINE where applicable.
Signed-off-by: Chris Packham <chris.packham@alliedtelesis.co.nz>
---
Changes in v3:
- new
arch/powerpc/configs/44x/akebono_defconfig | 2 --
arch/powerpc/configs/44x/arches_defconfig | 2 --
arch/powerpc/configs/44x/bamboo_defconfig | 2 --
arch/powerpc/configs/44x/bluestone_defconfig | 2 --
arch/powerpc/configs/44x/canyonlands_defconfig | 2 --
arch/powerpc/configs/44x/currituck_defconfig | 2 --
arch/powerpc/configs/44x/eiger_defconfig | 2 --
arch/powerpc/configs/44x/fsp2_defconfig | 1 -
arch/powerpc/configs/44x/icon_defconfig | 2 --
arch/powerpc/configs/44x/iss476-smp_defconfig | 1 -
arch/powerpc/configs/44x/katmai_defconfig | 2 --
arch/powerpc/configs/44x/rainier_defconfig | 2 --
arch/powerpc/configs/44x/redwood_defconfig | 2 --
arch/powerpc/configs/44x/sam440ep_defconfig | 2 --
arch/powerpc/configs/44x/sequoia_defconfig | 2 --
arch/powerpc/configs/44x/taishan_defconfig | 2 --
arch/powerpc/configs/44x/warp_defconfig | 1 -
arch/powerpc/configs/holly_defconfig | 1 -
arch/powerpc/configs/mvme5100_defconfig | 3 +--
arch/powerpc/configs/ps3_defconfig | 2 --
arch/powerpc/configs/skiroot_defconfig | 1 -
arch/powerpc/configs/storcenter_defconfig | 1 -
22 files changed, 1 insertion(+), 38 deletions(-)
diff --git a/arch/powerpc/configs/44x/akebono_defconfig b/arch/powerpc/configs/44x/akebono_defconfig
index 7705a5c3f4ea..60d5fa2c3b93 100644
--- a/arch/powerpc/configs/44x/akebono_defconfig
+++ b/arch/powerpc/configs/44x/akebono_defconfig
@@ -19,8 +19,6 @@ CONFIG_HIGHMEM=y
CONFIG_HZ_100=y
CONFIG_IRQ_ALL_CPUS=y
# CONFIG_COMPACTION is not set
-CONFIG_CMDLINE_BOOL=y
-CONFIG_CMDLINE=""
# CONFIG_SUSPEND is not set
CONFIG_NET=y
CONFIG_PACKET=y
diff --git a/arch/powerpc/configs/44x/arches_defconfig b/arch/powerpc/configs/44x/arches_defconfig
index 82c6f49b8dcb..41d04e70d4fb 100644
--- a/arch/powerpc/configs/44x/arches_defconfig
+++ b/arch/powerpc/configs/44x/arches_defconfig
@@ -11,8 +11,6 @@ CONFIG_MODULE_UNLOAD=y
# CONFIG_BLK_DEV_BSG is not set
# CONFIG_EBONY is not set
CONFIG_ARCHES=y
-CONFIG_CMDLINE_BOOL=y
-CONFIG_CMDLINE=""
CONFIG_NET=y
CONFIG_PACKET=y
CONFIG_UNIX=y
diff --git a/arch/powerpc/configs/44x/bamboo_defconfig b/arch/powerpc/configs/44x/bamboo_defconfig
index 679213214a75..acbce718eaa8 100644
--- a/arch/powerpc/configs/44x/bamboo_defconfig
+++ b/arch/powerpc/configs/44x/bamboo_defconfig
@@ -9,8 +9,6 @@ CONFIG_MODULE_UNLOAD=y
# CONFIG_BLK_DEV_BSG is not set
CONFIG_BAMBOO=y
# CONFIG_EBONY is not set
-CONFIG_CMDLINE_BOOL=y
-CONFIG_CMDLINE=""
CONFIG_NET=y
CONFIG_PACKET=y
CONFIG_UNIX=y
diff --git a/arch/powerpc/configs/44x/bluestone_defconfig b/arch/powerpc/configs/44x/bluestone_defconfig
index 8006a5728afd..37088f250c9e 100644
--- a/arch/powerpc/configs/44x/bluestone_defconfig
+++ b/arch/powerpc/configs/44x/bluestone_defconfig
@@ -11,8 +11,6 @@ CONFIG_EXPERT=y
# CONFIG_COMPAT_BRK is not set
CONFIG_BLUESTONE=y
# CONFIG_EBONY is not set
-CONFIG_CMDLINE_BOOL=y
-CONFIG_CMDLINE=""
CONFIG_NET=y
CONFIG_PACKET=y
CONFIG_UNIX=y
diff --git a/arch/powerpc/configs/44x/canyonlands_defconfig b/arch/powerpc/configs/44x/canyonlands_defconfig
index ccc14eb7a2f1..61776ade572b 100644
--- a/arch/powerpc/configs/44x/canyonlands_defconfig
+++ b/arch/powerpc/configs/44x/canyonlands_defconfig
@@ -11,8 +11,6 @@ CONFIG_MODULE_UNLOAD=y
# CONFIG_BLK_DEV_BSG is not set
# CONFIG_EBONY is not set
CONFIG_CANYONLANDS=y
-CONFIG_CMDLINE_BOOL=y
-CONFIG_CMDLINE=""
CONFIG_NET=y
CONFIG_PACKET=y
CONFIG_UNIX=y
diff --git a/arch/powerpc/configs/44x/currituck_defconfig b/arch/powerpc/configs/44x/currituck_defconfig
index be76e066df01..34c86b3abecb 100644
--- a/arch/powerpc/configs/44x/currituck_defconfig
+++ b/arch/powerpc/configs/44x/currituck_defconfig
@@ -17,8 +17,6 @@ CONFIG_HIGHMEM=y
CONFIG_HZ_100=y
CONFIG_MATH_EMULATION=y
CONFIG_IRQ_ALL_CPUS=y
-CONFIG_CMDLINE_BOOL=y
-CONFIG_CMDLINE=""
# CONFIG_SUSPEND is not set
CONFIG_NET=y
CONFIG_PACKET=y
diff --git a/arch/powerpc/configs/44x/eiger_defconfig b/arch/powerpc/configs/44x/eiger_defconfig
index 1abaa63e067f..509300f400e2 100644
--- a/arch/powerpc/configs/44x/eiger_defconfig
+++ b/arch/powerpc/configs/44x/eiger_defconfig
@@ -10,8 +10,6 @@ CONFIG_MODULES=y
CONFIG_MODULE_UNLOAD=y
# CONFIG_EBONY is not set
CONFIG_EIGER=y
-CONFIG_CMDLINE_BOOL=y
-CONFIG_CMDLINE=""
CONFIG_PCIEPORTBUS=y
# CONFIG_PCIEASPM is not set
CONFIG_NET=y
diff --git a/arch/powerpc/configs/44x/fsp2_defconfig b/arch/powerpc/configs/44x/fsp2_defconfig
index e67fc041ca3e..30845ce0885a 100644
--- a/arch/powerpc/configs/44x/fsp2_defconfig
+++ b/arch/powerpc/configs/44x/fsp2_defconfig
@@ -28,7 +28,6 @@ CONFIG_476FPE_ERR46=y
CONFIG_SWIOTLB=y
CONFIG_KEXEC=y
CONFIG_CRASH_DUMP=y
-CONFIG_CMDLINE_BOOL=y
CONFIG_CMDLINE="ip=on rw"
# CONFIG_SUSPEND is not set
# CONFIG_PCI is not set
diff --git a/arch/powerpc/configs/44x/icon_defconfig b/arch/powerpc/configs/44x/icon_defconfig
index 7d7ff84c8200..930948a1da76 100644
--- a/arch/powerpc/configs/44x/icon_defconfig
+++ b/arch/powerpc/configs/44x/icon_defconfig
@@ -9,8 +9,6 @@ CONFIG_MODULE_UNLOAD=y
# CONFIG_EBONY is not set
CONFIG_ICON=y
CONFIG_HIGHMEM=y
-CONFIG_CMDLINE_BOOL=y
-CONFIG_CMDLINE=""
CONFIG_PCIEPORTBUS=y
# CONFIG_PCIEASPM is not set
CONFIG_NET=y
diff --git a/arch/powerpc/configs/44x/iss476-smp_defconfig b/arch/powerpc/configs/44x/iss476-smp_defconfig
index fb5c73a29bf4..2c3834eebca3 100644
--- a/arch/powerpc/configs/44x/iss476-smp_defconfig
+++ b/arch/powerpc/configs/44x/iss476-smp_defconfig
@@ -17,7 +17,6 @@ CONFIG_ISS4xx=y
CONFIG_HZ_100=y
CONFIG_MATH_EMULATION=y
CONFIG_IRQ_ALL_CPUS=y
-CONFIG_CMDLINE_BOOL=y
CONFIG_CMDLINE="root=/dev/issblk0"
# CONFIG_PCI is not set
CONFIG_ADVANCED_OPTIONS=y
diff --git a/arch/powerpc/configs/44x/katmai_defconfig b/arch/powerpc/configs/44x/katmai_defconfig
index c6dc1445fc04..1a0f1c3e0ee9 100644
--- a/arch/powerpc/configs/44x/katmai_defconfig
+++ b/arch/powerpc/configs/44x/katmai_defconfig
@@ -9,8 +9,6 @@ CONFIG_MODULE_UNLOAD=y
# CONFIG_BLK_DEV_BSG is not set
# CONFIG_EBONY is not set
CONFIG_KATMAI=y
-CONFIG_CMDLINE_BOOL=y
-CONFIG_CMDLINE=""
CONFIG_NET=y
CONFIG_PACKET=y
CONFIG_UNIX=y
diff --git a/arch/powerpc/configs/44x/rainier_defconfig b/arch/powerpc/configs/44x/rainier_defconfig
index c83ad03182df..6dd67de06a0b 100644
--- a/arch/powerpc/configs/44x/rainier_defconfig
+++ b/arch/powerpc/configs/44x/rainier_defconfig
@@ -10,8 +10,6 @@ CONFIG_MODULE_UNLOAD=y
# CONFIG_EBONY is not set
CONFIG_RAINIER=y
CONFIG_MATH_EMULATION=y
-CONFIG_CMDLINE_BOOL=y
-CONFIG_CMDLINE=""
CONFIG_NET=y
CONFIG_PACKET=y
CONFIG_UNIX=y
diff --git a/arch/powerpc/configs/44x/redwood_defconfig b/arch/powerpc/configs/44x/redwood_defconfig
index 640fe1d5af28..e28d76416537 100644
--- a/arch/powerpc/configs/44x/redwood_defconfig
+++ b/arch/powerpc/configs/44x/redwood_defconfig
@@ -10,8 +10,6 @@ CONFIG_MODULES=y
CONFIG_MODULE_UNLOAD=y
# CONFIG_EBONY is not set
CONFIG_REDWOOD=y
-CONFIG_CMDLINE_BOOL=y
-CONFIG_CMDLINE=""
CONFIG_PCIEPORTBUS=y
# CONFIG_PCIEASPM is not set
CONFIG_NET=y
diff --git a/arch/powerpc/configs/44x/sam440ep_defconfig b/arch/powerpc/configs/44x/sam440ep_defconfig
index 22dc0dadf576..ef09786d49b9 100644
--- a/arch/powerpc/configs/44x/sam440ep_defconfig
+++ b/arch/powerpc/configs/44x/sam440ep_defconfig
@@ -12,8 +12,6 @@ CONFIG_PARTITION_ADVANCED=y
CONFIG_AMIGA_PARTITION=y
# CONFIG_EBONY is not set
CONFIG_SAM440EP=y
-CONFIG_CMDLINE_BOOL=y
-CONFIG_CMDLINE=""
CONFIG_NET=y
CONFIG_PACKET=y
CONFIG_UNIX=y
diff --git a/arch/powerpc/configs/44x/sequoia_defconfig b/arch/powerpc/configs/44x/sequoia_defconfig
index 2c0973db8837..b4984eab43eb 100644
--- a/arch/powerpc/configs/44x/sequoia_defconfig
+++ b/arch/powerpc/configs/44x/sequoia_defconfig
@@ -11,8 +11,6 @@ CONFIG_MODULE_UNLOAD=y
# CONFIG_BLK_DEV_BSG is not set
# CONFIG_EBONY is not set
CONFIG_SEQUOIA=y
-CONFIG_CMDLINE_BOOL=y
-CONFIG_CMDLINE=""
CONFIG_NET=y
CONFIG_PACKET=y
CONFIG_UNIX=y
diff --git a/arch/powerpc/configs/44x/taishan_defconfig b/arch/powerpc/configs/44x/taishan_defconfig
index a2d355ca62b2..3ea5932ab852 100644
--- a/arch/powerpc/configs/44x/taishan_defconfig
+++ b/arch/powerpc/configs/44x/taishan_defconfig
@@ -9,8 +9,6 @@ CONFIG_MODULE_UNLOAD=y
# CONFIG_BLK_DEV_BSG is not set
# CONFIG_EBONY is not set
CONFIG_TAISHAN=y
-CONFIG_CMDLINE_BOOL=y
-CONFIG_CMDLINE=""
CONFIG_NET=y
CONFIG_PACKET=y
CONFIG_UNIX=y
diff --git a/arch/powerpc/configs/44x/warp_defconfig b/arch/powerpc/configs/44x/warp_defconfig
index af66c69c49fe..47252c2d7669 100644
--- a/arch/powerpc/configs/44x/warp_defconfig
+++ b/arch/powerpc/configs/44x/warp_defconfig
@@ -14,7 +14,6 @@ CONFIG_MODULE_UNLOAD=y
CONFIG_WARP=y
CONFIG_PPC4xx_GPIO=y
CONFIG_HZ_1000=y
-CONFIG_CMDLINE_BOOL=y
CONFIG_CMDLINE="ip=on"
# CONFIG_PCI is not set
CONFIG_NET=y
diff --git a/arch/powerpc/configs/holly_defconfig b/arch/powerpc/configs/holly_defconfig
index 067f433c8f5e..271daff47d1d 100644
--- a/arch/powerpc/configs/holly_defconfig
+++ b/arch/powerpc/configs/holly_defconfig
@@ -13,7 +13,6 @@ CONFIG_EMBEDDED6xx=y
CONFIG_PPC_HOLLY=y
CONFIG_GEN_RTC=y
CONFIG_BINFMT_MISC=y
-CONFIG_CMDLINE_BOOL=y
CONFIG_CMDLINE="console=ttyS0,115200"
# CONFIG_SECCOMP is not set
CONFIG_NET=y
diff --git a/arch/powerpc/configs/mvme5100_defconfig b/arch/powerpc/configs/mvme5100_defconfig
index 0a0d046fc445..3d53d69ed36c 100644
--- a/arch/powerpc/configs/mvme5100_defconfig
+++ b/arch/powerpc/configs/mvme5100_defconfig
@@ -20,10 +20,9 @@ CONFIG_EMBEDDED6xx=y
CONFIG_MVME5100=y
CONFIG_KVM_GUEST=y
CONFIG_HZ_100=y
+CONFIG_CMDLINE="console=ttyS0,9600 ip=dhcp root=/dev/nfs"
# CONFIG_CORE_DUMP_DEFAULT_ELF_HEADERS is not set
# CONFIG_COMPACTION is not set
-CONFIG_CMDLINE_BOOL=y
-CONFIG_CMDLINE="console=ttyS0,9600 ip=dhcp root=/dev/nfs"
CONFIG_NET=y
CONFIG_PACKET=y
CONFIG_UNIX=y
diff --git a/arch/powerpc/configs/ps3_defconfig b/arch/powerpc/configs/ps3_defconfig
index 81b55c880fc3..142f1321fa58 100644
--- a/arch/powerpc/configs/ps3_defconfig
+++ b/arch/powerpc/configs/ps3_defconfig
@@ -34,8 +34,6 @@ CONFIG_KEXEC=y
# CONFIG_SPARSEMEM_VMEMMAP is not set
# CONFIG_COMPACTION is not set
CONFIG_SCHED_SMT=y
-CONFIG_CMDLINE_BOOL=y
-CONFIG_CMDLINE=""
CONFIG_PM=y
CONFIG_PM_DEBUG=y
# CONFIG_SECCOMP is not set
diff --git a/arch/powerpc/configs/skiroot_defconfig b/arch/powerpc/configs/skiroot_defconfig
index ad6739ac63dc..b806a5d3a695 100644
--- a/arch/powerpc/configs/skiroot_defconfig
+++ b/arch/powerpc/configs/skiroot_defconfig
@@ -45,7 +45,6 @@ CONFIG_IRQ_ALL_CPUS=y
CONFIG_NUMA=y
CONFIG_PPC_64K_PAGES=y
CONFIG_SCHED_SMT=y
-CONFIG_CMDLINE_BOOL=y
CONFIG_CMDLINE="console=tty0 console=hvc0 ipr.fast_reboot=1 quiet"
# CONFIG_SECCOMP is not set
# CONFIG_PPC_MEM_KEYS is not set
diff --git a/arch/powerpc/configs/storcenter_defconfig b/arch/powerpc/configs/storcenter_defconfig
index b964084e4056..47dcfaddc1ac 100644
--- a/arch/powerpc/configs/storcenter_defconfig
+++ b/arch/powerpc/configs/storcenter_defconfig
@@ -12,7 +12,6 @@ CONFIG_EMBEDDED6xx=y
CONFIG_STORCENTER=y
CONFIG_HZ_100=y
CONFIG_BINFMT_MISC=y
-CONFIG_CMDLINE_BOOL=y
CONFIG_CMDLINE="console=ttyS0,115200"
# CONFIG_SECCOMP is not set
CONFIG_NET=y
--
2.27.0
^ permalink raw reply related
* Re: [PATCH v4 1/2] powerpc/uaccess: Implement unsafe_put_user() using 'asm goto'
From: Nick Desaulniers @ 2020-06-11 22:43 UTC (permalink / raw)
To: patch-notifications, christophe.leroy, segher
Cc: linux-kernel, npiggin, clang-built-linux, paulus, linuxppc-dev
In-Reply-To: <49YBKY13Szz9sT4@ozlabs.org>
Hello! It seems this patch broke our ppc32 builds, and we had to
disable them [0]. :(
From what I can tell, though Michael mentioned this was merged on May
29, but our CI of -next was green for ppc32 until June 4, then mainline
went red June 6. So this patch only got 2 days of soak time before the
merge window opened.
A general issue with the -next workflow seems to be that patches get
different amounts of soak time. For higher risk patches like this one,
can I please ask that they be help back a release if close to the merge
window?
Segher, Cristophe, I suspect Clang is missing support for the %L and %U
output templates [1]. I've implemented support for some of these before
in Clang via the documentation at [2], but these seem to be machine
specific? Can you please point me to documentation/unit tests/source for
these so that I can figure out what they should be doing, and look into
implementing them in Clang?
[0] https://github.com/ClangBuiltLinux/continuous-integration/pull/279
[1] https://bugs.llvm.org/show_bug.cgi?id=46186
[2]
https://gcc.gnu.org/onlinedocs/gccint/Output-Template.html#Output-Template
^ permalink raw reply
* Re: [PATCH v4 1/2] powerpc/uaccess: Implement unsafe_put_user() using 'asm goto'
From: Segher Boessenkool @ 2020-06-11 23:52 UTC (permalink / raw)
To: Nick Desaulniers
Cc: christophe.leroy, patch-notifications, linux-kernel, npiggin,
clang-built-linux, paulus, linuxppc-dev
In-Reply-To: <20200611224355.71174-1-ndesaulniers@google.com>
On Thu, Jun 11, 2020 at 03:43:55PM -0700, Nick Desaulniers wrote:
> Segher, Cristophe, I suspect Clang is missing support for the %L and %U
> output templates [1].
The arch/powerpc kernel first used the %U output modifier in 0c176fa80fdf
(from 2016), and %L in b8b572e1015f (2008). include/asm-ppc (and ppc64)
have had %U since 2005 (1da177e4c3f4), and %L as well (0c541b4406a6).
> I've implemented support for some of these before
> in Clang via the documentation at [2], but these seem to be machine
> specific?
Yes, almost all output modifiers are. Only %l, %a, %n, and part of %c
are generic (and %% and %= and on some targets, %{, %|, %}).
> Can you please point me to documentation/unit tests/source for
> these so that I can figure out what they should be doing, and look into
> implementing them in Clang?
The PowerPC part of
https://gcc.gnu.org/onlinedocs/gcc/Machine-Constraints.html#Machine-Constraints
(sorry, no anchor) documents %U.
Traditionally the source code is the documentation for this. The code
here starts with the comment
/* Write second word of DImode or DFmode reference. Works on register
or non-indexed memory only. */
(which is very out-of-date itself, it works fine for e.g. TImode as well,
but alas).
Unit tests are completely unsuitable for most compiler things like this.
The source code is gcc/config/rs6000/rs6000.c, easiest is to search for
'L' (with those quotes). Function print_operand.
HtH,
Segher
^ permalink raw reply
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