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 <jpoim...@kernel.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 872947c1004c..506c9800a5aa 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> /* 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> -- 2.48.1