[PATCH v6 3/6] x86/asm: Simplify VDSO DWARF generation
From: Jens Remus <hidden>
Date: 2026-01-29 11:28:18
Also in:
bpf, linux-mm, lkml
Subsystem:
the rest, x86 architecture (32-bit and 64-bit), x86 entry code, x86 vdso · Maintainers:
Linus Torvalds, Thomas Gleixner, Ingo Molnar, Borislav Petkov, Dave Hansen, Andy Lutomirski
From: Josh Poimboeuf <jpoimboe@kernel.org> Add CFI_STARTPROC and CFI_ENDPROC annotations to the SYM_FUNC_* macros so the VDSO asm functions don't need to add them manually. Note this only affects VDSO, the CFI_* macros are empty for the kernel proper. [ Jens Remus: Reword commit subject and message as suggested by Josh. ] Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Jens Remus <redacted> --- 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 9d38ae744a2e..9d7f90c57451 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) /* * Expose 'sym' to the startup code in arch/x86/boot/startup/, by emitting an
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>
--
2.51.0