diff options
Diffstat (limited to 'arch/x86/include/asm')
| -rw-r--r-- | arch/x86/include/asm/alternative.h | 1 | ||||
| -rw-r--r-- | arch/x86/include/asm/ibt.h | 12 |
2 files changed, 13 insertions, 0 deletions
diff --git a/arch/x86/include/asm/alternative.h b/arch/x86/include/asm/alternative.h index 58eee6402832..9b10c8c76087 100644 --- a/arch/x86/include/asm/alternative.h +++ b/arch/x86/include/asm/alternative.h @@ -76,6 +76,7 @@ extern int alternatives_patched; extern void alternative_instructions(void); extern void apply_alternatives(struct alt_instr *start, struct alt_instr *end); extern void apply_retpolines(s32 *start, s32 *end); +extern void apply_ibt_endbr(s32 *start, s32 *end); struct module; diff --git a/arch/x86/include/asm/ibt.h b/arch/x86/include/asm/ibt.h index 52fb05d66489..689880eca9ba 100644 --- a/arch/x86/include/asm/ibt.h +++ b/arch/x86/include/asm/ibt.h @@ -46,8 +46,20 @@ static inline __attribute_const__ u32 gen_endbr(void) return endbr; } +static inline __attribute_const__ u32 gen_endbr_poison(void) +{ + /* + * 4 byte NOP that isn't NOP4 (in fact it is OSP NOP3), such that it + * will be unique to (former) ENDBR sites. + */ + return 0x001f0f66; /* osp nopl (%rax) */ +} + static inline bool is_endbr(u32 val) { + if (val == gen_endbr_poison()) + return true; + val &= ~0x01000000U; /* ENDBR32 -> ENDBR64 */ return val == gen_endbr(); } |