diff options
Diffstat (limited to 'arch/x86/lib')
| -rw-r--r-- | arch/x86/lib/retpoline.S | 28 |
1 files changed, 28 insertions, 0 deletions
diff --git a/arch/x86/lib/retpoline.S b/arch/x86/lib/retpoline.S index a26c43abd47d..a06891892853 100644 --- a/arch/x86/lib/retpoline.S +++ b/arch/x86/lib/retpoline.S @@ -367,6 +367,34 @@ SYM_FUNC_END(call_depth_return_thunk) #endif /* CONFIG_MITIGATION_CALL_DEPTH_TRACKING */ +#ifdef CONFIG_MITIGATION_ITS + +.macro ITS_THUNK reg + +SYM_INNER_LABEL(__x86_indirect_its_thunk_\reg, SYM_L_GLOBAL) + UNWIND_HINT_UNDEFINED + ANNOTATE_NOENDBR + ANNOTATE_RETPOLINE_SAFE + jmp *%\reg + int3 + .align 32, 0xcc /* fill to the end of the line */ + .skip 32, 0xcc /* skip to the next upper half */ +.endm + +/* ITS mitigation requires thunks be aligned to upper half of cacheline */ +.align 64, 0xcc +.skip 32, 0xcc +SYM_CODE_START(__x86_indirect_its_thunk_array) + +#define GEN(reg) ITS_THUNK reg +#include <asm/GEN-for-each-reg.h> +#undef GEN + + .align 64, 0xcc +SYM_CODE_END(__x86_indirect_its_thunk_array) + +#endif + /* * This function name is magical and is used by -mfunction-return=thunk-extern * for the compiler to generate JMPs to it. |