From 5d1dd961e74334a2178264193ea813d44ce5e725 Mon Sep 17 00:00:00 2001 From: "Borislav Petkov (AMD)" Date: Thu, 22 Dec 2022 12:42:24 +0100 Subject: x86/alternatives: Add alt_instr.flags Add a struct alt_instr.flags field which will contain different flags controlling alternatives patching behavior. The initial idea was to be able to specify it as a separate macro parameter but that would mean touching all possible invocations of the alternatives macros and thus a lot of churn. What is more, as PeterZ suggested, being able to say ALT_NOT(feature) is very readable and explains exactly what is meant. So make the feature field a u32 where the patching flags are the upper u16 part of the dword quantity while the lower u16 word is the feature. The highest feature number currently is 0x26a (i.e., word 19) so there is plenty of space. If that becomes insufficient, the field can be extended to u64 which will then make struct alt_instr of the nice size of 16 bytes (14 bytes currently). There should be no functional changes resulting from this. Suggested-by: Peter Zijlstra (Intel) Signed-off-by: Borislav Petkov (AMD) Reviewed-by: Ingo Molnar Link: https://lore.kernel.org/r/Y6RCoJEtxxZWwotd@zn.tnic --- tools/objtool/arch/x86/include/arch/special.h | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) (limited to 'tools/objtool') diff --git a/tools/objtool/arch/x86/include/arch/special.h b/tools/objtool/arch/x86/include/arch/special.h index f2918f789a0a..ca8131352994 100644 --- a/tools/objtool/arch/x86/include/arch/special.h +++ b/tools/objtool/arch/x86/include/arch/special.h @@ -11,11 +11,11 @@ #define JUMP_NEW_OFFSET 4 #define JUMP_KEY_OFFSET 8 -#define ALT_ENTRY_SIZE 12 +#define ALT_ENTRY_SIZE 14 #define ALT_ORIG_OFFSET 0 #define ALT_NEW_OFFSET 4 #define ALT_FEATURE_OFFSET 8 -#define ALT_ORIG_LEN_OFFSET 10 -#define ALT_NEW_LEN_OFFSET 11 +#define ALT_ORIG_LEN_OFFSET 12 +#define ALT_NEW_LEN_OFFSET 13 #endif /* _X86_ARCH_SPECIAL_H */ -- cgit v1.2.3