From c4691712b546b93707a408368e3c57ae870a2dc4 Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Tue, 8 Mar 2022 16:30:25 +0100 Subject: [PATCH] x86/linkage: Add ENDBR to SYM_FUNC_START*() Ensure the ASM functions have ENDBR on for IBT builds, this follows the ARM64 example. Unlike ARM64, we'll likely end up overwriting them with poison. Suggested-by: Mark Rutland Signed-off-by: Peter Zijlstra (Intel) Reviewed-by: Kees Cook Acked-by: Josh Poimboeuf Link: https://lore.kernel.org/r/20220308154317.992708941@infradead.org --- arch/x86/include/asm/linkage.h | 31 +++++++++++++++++++++++++++++++ 1 file changed, 31 insertions(+) diff --git a/arch/x86/include/asm/linkage.h b/arch/x86/include/asm/linkage.h index 030907922bd0..85865f1645bd 100644 --- a/arch/x86/include/asm/linkage.h +++ b/arch/x86/include/asm/linkage.h @@ -3,6 +3,7 @@ #define _ASM_X86_LINKAGE_H #include +#include #undef notrace #define notrace __attribute__((no_instrument_function)) @@ -34,5 +35,35 @@ #endif /* __ASSEMBLY__ */ +/* SYM_FUNC_START -- use for global functions */ +#define SYM_FUNC_START(name) \ + SYM_START(name, SYM_L_GLOBAL, SYM_A_ALIGN) \ + ENDBR + +/* 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_LOCAL -- use for local functions */ +#define SYM_FUNC_START_LOCAL(name) \ + SYM_START(name, SYM_L_LOCAL, SYM_A_ALIGN) \ + ENDBR + +/* 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_WEAK -- use for weak functions */ +#define SYM_FUNC_START_WEAK(name) \ + SYM_START(name, SYM_L_WEAK, SYM_A_ALIGN) \ + ENDBR + +/* 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 + #endif /* _ASM_X86_LINKAGE_H */ -- 2.11.0