linux-kernel - [PATCH v3 03/19] x86/asm: Fix VDSO DWARF generation with kernel IBT enabled

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives
Hash Suite: Windows password security audit tool. GUI, reports in PDF.
[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <b1b8498a9aa9f6dfb69dc27f9bc8b21656c5e7ab.1730150953.git.jpoimboe@kernel.org>
Date: Mon, 28 Oct 2024 14:47:30 -0700
From: Josh Poimboeuf <jpoimboe@...nel.org>
To: x86@...nel.org
Cc: Peter Zijlstra <peterz@...radead.org>,
	Steven Rostedt <rostedt@...dmis.org>,
	Ingo Molnar <mingo@...nel.org>,
	Arnaldo Carvalho de Melo <acme@...nel.org>,
	linux-kernel@...r.kernel.org,
	Indu Bhagat <indu.bhagat@...cle.com>,
	Mark Rutland <mark.rutland@....com>,
	Alexander Shishkin <alexander.shishkin@...ux.intel.com>,
	Jiri Olsa <jolsa@...nel.org>,
	Namhyung Kim <namhyung@...nel.org>,
	Ian Rogers <irogers@...gle.com>,
	Adrian Hunter <adrian.hunter@...el.com>,
	linux-perf-users@...r.kernel.org,
	Mark Brown <broonie@...nel.org>,
	linux-toolchains@...r.kernel.org,
	Jordan Rome <jordalgo@...a.com>,
	Sam James <sam@...too.org>,
	linux-trace-kernel@...r.kerne.org,
	Andrii Nakryiko <andrii.nakryiko@...il.com>,
	Jens Remus <jremus@...ux.ibm.com>,
	Mathieu Desnoyers <mathieu.desnoyers@...icios.com>,
	Florian Weimer <fweimer@...hat.com>,
	Andy Lutomirski <luto@...nel.org>
Subject: [PATCH v3 03/19] x86/asm: Fix VDSO DWARF generation with kernel IBT enabled

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.  So the DWARF unwinding info is
wrong at the beginning of 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@...nel.org>
---
 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          | 29 +++++++++++++++++++------
 arch/x86/include/asm/vdso.h             |  1 -
 5 files changed, 23 insertions(+), 15 deletions(-)

diff --git a/arch/x86/entry/vdso/vdso-layout.lds.S b/arch/x86/entry/vdso/vdso-layout.lds.S
index bafa73f09e92..a42c7d4a33da 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>
 
 /*
  * Linker script for vDSO.  This is an ELF shared object prelinked to
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 dc31b13b87a0..2866d57ef907 100644
--- a/arch/x86/include/asm/linkage.h
+++ b/arch/x86/include/asm/linkage.h
@@ -40,6 +40,10 @@
 
 #ifdef __ASSEMBLY__
 
+#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 */
@@ -112,40 +116,51 @@
 # define SYM_FUNC_ALIAS_MEMFUNC	SYM_FUNC_ALIAS
 #endif
 
+#define __SYM_FUNC_START				\
+	CFI_STARTPROC ASM_NL				\
+	ENDBR
+
+#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)	\
-	ENDBR
+	__SYM_FUNC_START
 
 /* SYM_FUNC_START -- use for global functions */
 #define SYM_FUNC_START(name)				\
 	SYM_START(name, SYM_L_GLOBAL, SYM_F_ALIGN)	\
-	ENDBR
+	__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)	\
-	ENDBR
+	__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)	\
-	ENDBR
+	__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)	\
-	ENDBR
+	__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)	\
-	ENDBR
+	__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)		\
-	ENDBR
+	__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 d7f6592b74a9..0111c349bbc5 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>
 
-- 
2.47.0