From: Steven Rostedt <rostedt@goodmis.org>
To: linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org
Cc: Masami Hiramatsu <mhiramat@kernel.org>,
Mark Rutland <mark.rutland@arm.com>,
Mathieu Desnoyers <mathieu.desnoyers@efficios.com>,
Andrew Morton <akpm@linux-foundation.org>,
Josh Poimboeuf <jpoimboe@kernel.org>,
Jens Remus <jremus@linux.ibm.com>,
x86@kernel.org, Peter Zijlstra <peterz@infradead.org>,
Ingo Molnar <mingo@kernel.org>,
Indu Bhagat <indu.bhagat@oracle.com>,
Andy Lutomirski <luto@kernel.org>,
Thomas Gleixner <tglx@linutronix.de>,
Borislav Petkov <bp@alien8.de>,
Dave Hansen <dave.hansen@linux.intel.com>,
"H. Peter Anvin" <hpa@zytor.com>
Subject: [PATCH v5 3/6] x86/asm: Fix VDSO DWARF generation with kernel IBT enabled
Date: Tue, 22 Apr 2025 14:34:42 -0400 [thread overview]
Message-ID: <20250422183722.404841398@goodmis.org> (raw)
In-Reply-To: 20250422183439.895236512@goodmis.org
From: Josh Poimboeuf <jpoimboe@kernel.org>
The DWARF .cfi_startproc annotation needs to be at the very beginning of
a function. But with kernel IBT that doesn't happen as ENDBR is
sneakily embedded in SYM_FUNC_START. As a result the DWARF unwinding
info is wrong at the beginning of all the VDSO functions.
Fix it by adding CFI_STARTPROC and CFI_ENDPROC to SYM_FUNC_START_* and
SYM_FUNC_END respectively. Note this only affects VDSO, as the CFI_*
macros are empty for the kernel proper.
Fixes: c4691712b546 ("x86/linkage: Add ENDBR to SYM_FUNC_START*()")
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
[ Fixed rebased issues. May need extra review ]
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
---
Changes since v4: https://lore.kernel.org/all/5c7992c111adee94e242fbca2b3e64ab8e96e595.1737511963.git.jpoimboe@kernel.org/
- Rebased to latest kernel which had changes to the ENDBR caused by:
582077c94052 ("x86/cfi: Clean up linkage")
arch/x86/entry/vdso/vdso-layout.lds.S | 2 +-
arch/x86/entry/vdso/vgetrandom-chacha.S | 2 --
arch/x86/entry/vdso/vsgx.S | 4 ---
arch/x86/include/asm/linkage.h | 33 ++++++++++++++++++++-----
arch/x86/include/asm/vdso.h | 1 -
5 files changed, 28 insertions(+), 14 deletions(-)
diff --git a/arch/x86/entry/vdso/vdso-layout.lds.S b/arch/x86/entry/vdso/vdso-layout.lds.S
index ec1ac191a057..60747905de2b 100644
--- a/arch/x86/entry/vdso/vdso-layout.lds.S
+++ b/arch/x86/entry/vdso/vdso-layout.lds.S
@@ -1,5 +1,5 @@
/* SPDX-License-Identifier: GPL-2.0 */
-#include <asm/vdso.h>
+#include <asm/page_types.h>
#include <asm/vdso/vsyscall.h>
#include <vdso/datapage.h>
diff --git a/arch/x86/entry/vdso/vgetrandom-chacha.S b/arch/x86/entry/vdso/vgetrandom-chacha.S
index cc82da9216fb..a33212594731 100644
--- a/arch/x86/entry/vdso/vgetrandom-chacha.S
+++ b/arch/x86/entry/vdso/vgetrandom-chacha.S
@@ -22,7 +22,6 @@ CONSTANTS: .octa 0x6b20657479622d323320646e61707865
* rcx: number of 64-byte blocks to write to output
*/
SYM_FUNC_START(__arch_chacha20_blocks_nostack)
- CFI_STARTPROC
.set output, %rdi
.set key, %rsi
.set counter, %rdx
@@ -175,5 +174,4 @@ SYM_FUNC_START(__arch_chacha20_blocks_nostack)
pxor temp,temp
ret
- CFI_ENDPROC
SYM_FUNC_END(__arch_chacha20_blocks_nostack)
diff --git a/arch/x86/entry/vdso/vsgx.S b/arch/x86/entry/vdso/vsgx.S
index 37a3d4c02366..c0342238c976 100644
--- a/arch/x86/entry/vdso/vsgx.S
+++ b/arch/x86/entry/vdso/vsgx.S
@@ -24,8 +24,6 @@
.section .text, "ax"
SYM_FUNC_START(__vdso_sgx_enter_enclave)
- /* Prolog */
- .cfi_startproc
push %rbp
.cfi_adjust_cfa_offset 8
.cfi_rel_offset %rbp, 0
@@ -143,8 +141,6 @@ SYM_FUNC_START(__vdso_sgx_enter_enclave)
jle .Lout
jmp .Lenter_enclave
- .cfi_endproc
-
_ASM_VDSO_EXTABLE_HANDLE(.Lenclu_eenter_eresume, .Lhandle_exception)
SYM_FUNC_END(__vdso_sgx_enter_enclave)
diff --git a/arch/x86/include/asm/linkage.h b/arch/x86/include/asm/linkage.h
index b51d8a4673f5..1ba1f208414f 100644
--- a/arch/x86/include/asm/linkage.h
+++ b/arch/x86/include/asm/linkage.h
@@ -40,6 +40,10 @@
#ifdef __ASSEMBLER__
+#ifndef LINKER_SCRIPT
+#include <asm/dwarf2.h>
+#endif
+
#if defined(CONFIG_MITIGATION_RETHUNK) && !defined(__DISABLE_EXPORTS) && !defined(BUILD_VDSO)
#define RET jmp __x86_return_thunk
#else /* CONFIG_MITIGATION_RETPOLINE */
@@ -112,34 +116,51 @@
# define SYM_FUNC_ALIAS_MEMFUNC SYM_FUNC_ALIAS
#endif
+#define __SYM_FUNC_START \
+ CFI_STARTPROC ASM_NL
+
+#define __SYM_FUNC_END \
+ CFI_ENDPROC ASM_NL
+
/* SYM_TYPED_FUNC_START -- use for indirectly called globals, w/ CFI type */
#define SYM_TYPED_FUNC_START(name) \
SYM_TYPED_START(name, SYM_L_GLOBAL, SYM_F_ALIGN) \
+ __SYM_FUNC_START \
ENDBR
/* SYM_FUNC_START -- use for global functions */
#define SYM_FUNC_START(name) \
- SYM_START(name, SYM_L_GLOBAL, SYM_F_ALIGN)
+ SYM_START(name, SYM_L_GLOBAL, SYM_F_ALIGN) \
+ __SYM_FUNC_START
/* SYM_FUNC_START_NOALIGN -- use for global functions, w/o alignment */
#define SYM_FUNC_START_NOALIGN(name) \
- SYM_START(name, SYM_L_GLOBAL, SYM_A_NONE)
+ SYM_START(name, SYM_L_GLOBAL, SYM_A_NONE) \
+ __SYM_FUNC_START
/* SYM_FUNC_START_LOCAL -- use for local functions */
#define SYM_FUNC_START_LOCAL(name) \
- SYM_START(name, SYM_L_LOCAL, SYM_F_ALIGN)
+ SYM_START(name, SYM_L_LOCAL, SYM_F_ALIGN) \
+ __SYM_FUNC_START
/* SYM_FUNC_START_LOCAL_NOALIGN -- use for local functions, w/o alignment */
#define SYM_FUNC_START_LOCAL_NOALIGN(name) \
- SYM_START(name, SYM_L_LOCAL, SYM_A_NONE)
+ SYM_START(name, SYM_L_LOCAL, SYM_A_NONE) \
+ __SYM_FUNC_START
/* SYM_FUNC_START_WEAK -- use for weak functions */
#define SYM_FUNC_START_WEAK(name) \
- SYM_START(name, SYM_L_WEAK, SYM_F_ALIGN)
+ SYM_START(name, SYM_L_WEAK, SYM_F_ALIGN) \
+ __SYM_FUNC_START
/* SYM_FUNC_START_WEAK_NOALIGN -- use for weak functions, w/o alignment */
#define SYM_FUNC_START_WEAK_NOALIGN(name) \
- SYM_START(name, SYM_L_WEAK, SYM_A_NONE)
+ SYM_START(name, SYM_L_WEAK, SYM_A_NONE) \
+ __SYM_FUNC_START
+
+#define SYM_FUNC_END(name) \
+ __SYM_FUNC_END \
+ SYM_END(name, SYM_T_FUNC)
#endif /* _ASM_X86_LINKAGE_H */
diff --git a/arch/x86/include/asm/vdso.h b/arch/x86/include/asm/vdso.h
index b7253ef3205a..c4290dadba66 100644
--- a/arch/x86/include/asm/vdso.h
+++ b/arch/x86/include/asm/vdso.h
@@ -2,7 +2,6 @@
#ifndef _ASM_X86_VDSO_H
#define _ASM_X86_VDSO_H
-#include <asm/page_types.h>
#include <linux/linkage.h>
#include <linux/init.h>
--
2.47.2
next prev parent reply other threads:[~2025-04-22 18:35 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-04-22 18:34 [PATCH v5 0/6] x86/vdso: VDSO updates and fixes for sframes Steven Rostedt
2025-04-22 18:34 ` [PATCH v5 1/6] x86/vdso: Fix DWARF generation for getrandom() Steven Rostedt
2025-04-22 18:34 ` [PATCH v5 2/6] x86/asm: Avoid emitting DWARF CFI for non-VDSO Steven Rostedt
2025-04-22 18:34 ` Steven Rostedt [this message]
2025-04-23 0:44 ` [PATCH v5 3/6] x86/asm: Fix VDSO DWARF generation with kernel IBT enabled Josh Poimboeuf
2025-04-22 18:34 ` [PATCH v5 4/6] x86/vdso: Use SYM_FUNC_{START,END} in __kernel_vsyscall() Steven Rostedt
2025-04-22 18:34 ` [PATCH v5 5/6] x86/vdso: Use CFI macros in __vdso_sgx_enter_enclave() Steven Rostedt
2025-04-22 18:34 ` [PATCH v5 6/6] x86/vdso: Enable sframe generation in VDSO Steven Rostedt
2025-04-23 0:53 ` Josh Poimboeuf
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