diff options
Diffstat (limited to 'arch/x86/lib')
| -rw-r--r-- | arch/x86/lib/retpoline.S | 41 |
1 files changed, 40 insertions, 1 deletions
diff --git a/arch/x86/lib/retpoline.S b/arch/x86/lib/retpoline.S index d2c0d14c1e22..4d32cb06ffd5 100644 --- a/arch/x86/lib/retpoline.S +++ b/arch/x86/lib/retpoline.S @@ -10,6 +10,8 @@ #include <asm/unwind_hints.h> #include <asm/frame.h> + .section .text.__x86.indirect_thunk + .macro RETPOLINE reg ANNOTATE_INTRA_FUNCTION_CALL call .Ldo_rop_\@ @@ -25,9 +27,9 @@ .endm .macro THUNK reg - .section .text.__x86.indirect_thunk .align 32 + SYM_FUNC_START(__x86_indirect_thunk_\reg) ALTERNATIVE_2 __stringify(ANNOTATE_RETPOLINE_SAFE; jmp *%\reg), \ @@ -39,6 +41,32 @@ SYM_FUNC_END(__x86_indirect_thunk_\reg) .endm /* + * This generates .altinstr_replacement symbols for use by objtool. They, + * however, must not actually live in .altinstr_replacement since that will be + * discarded after init, but module alternatives will also reference these + * symbols. + * + * Their names matches the "__x86_indirect_" prefix to mark them as retpolines. + */ +.macro ALT_THUNK reg + + .align 1 + +SYM_FUNC_START_NOALIGN(__x86_indirect_alt_call_\reg) + ANNOTATE_RETPOLINE_SAFE +1: call *%\reg +2: .skip 5-(2b-1b), 0x90 +SYM_FUNC_END(__x86_indirect_alt_call_\reg) + +SYM_FUNC_START_NOALIGN(__x86_indirect_alt_jmp_\reg) + ANNOTATE_RETPOLINE_SAFE +1: jmp *%\reg +2: .skip 5-(2b-1b), 0x90 +SYM_FUNC_END(__x86_indirect_alt_jmp_\reg) + +.endm + +/* * Despite being an assembler file we can't just use .irp here * because __KSYM_DEPS__ only uses the C preprocessor and would * only see one instance of "__x86_indirect_thunk_\reg" rather @@ -61,3 +89,14 @@ SYM_FUNC_END(__x86_indirect_thunk_\reg) #define GEN(reg) EXPORT_THUNK(reg) #include <asm/GEN-for-each-reg.h> +#undef GEN +#define GEN(reg) ALT_THUNK reg +#include <asm/GEN-for-each-reg.h> + +#undef GEN +#define GEN(reg) __EXPORT_THUNK(__x86_indirect_alt_call_ ## reg) +#include <asm/GEN-for-each-reg.h> + +#undef GEN +#define GEN(reg) __EXPORT_THUNK(__x86_indirect_alt_jmp_ ## reg) +#include <asm/GEN-for-each-reg.h> |