diff options
Diffstat (limited to 'arch/x86/lib/retpoline.S')
| -rw-r--r-- | arch/x86/lib/retpoline.S | 46 |
1 files changed, 25 insertions, 21 deletions
diff --git a/arch/x86/lib/retpoline.S b/arch/x86/lib/retpoline.S index 5b26a952e2..391059b2c6 100644 --- a/arch/x86/lib/retpoline.S +++ b/arch/x86/lib/retpoline.S @@ -71,7 +71,7 @@ SYM_CODE_END(__x86_indirect_thunk_array) #include <asm/GEN-for-each-reg.h> #undef GEN -#ifdef CONFIG_CALL_DEPTH_TRACKING +#ifdef CONFIG_MITIGATION_CALL_DEPTH_TRACKING .macro CALL_THUNK reg .align RETPOLINE_THUNK_SIZE @@ -127,7 +127,7 @@ SYM_CODE_END(__x86_indirect_jump_thunk_array) #undef GEN #endif -#ifdef CONFIG_RETHUNK +#ifdef CONFIG_MITIGATION_RETHUNK /* * Be careful here: that label cannot really be removed because in @@ -138,7 +138,7 @@ SYM_CODE_END(__x86_indirect_jump_thunk_array) */ .section .text..__x86.return_thunk -#ifdef CONFIG_CPU_SRSO +#ifdef CONFIG_MITIGATION_SRSO /* * srso_alias_untrain_ret() and srso_alias_safe_ret() are placed at @@ -225,8 +225,7 @@ SYM_CODE_START(srso_return_thunk) SYM_CODE_END(srso_return_thunk) #define JMP_SRSO_UNTRAIN_RET "jmp srso_untrain_ret" -#else /* !CONFIG_CPU_SRSO */ -#define JMP_SRSO_UNTRAIN_RET "ud2" +#else /* !CONFIG_MITIGATION_SRSO */ /* Dummy for the alternative in CALL_UNTRAIN_RET. */ SYM_CODE_START(srso_alias_untrain_ret) ANNOTATE_UNRET_SAFE @@ -235,9 +234,10 @@ SYM_CODE_START(srso_alias_untrain_ret) int3 SYM_FUNC_END(srso_alias_untrain_ret) __EXPORT_THUNK(srso_alias_untrain_ret) -#endif /* CONFIG_CPU_SRSO */ +#define JMP_SRSO_UNTRAIN_RET "ud2" +#endif /* CONFIG_MITIGATION_SRSO */ -#ifdef CONFIG_CPU_UNRET_ENTRY +#ifdef CONFIG_MITIGATION_UNRET_ENTRY /* * Some generic notes on the untraining sequences: @@ -319,20 +319,20 @@ SYM_CODE_END(retbleed_return_thunk) SYM_FUNC_END(retbleed_untrain_ret) #define JMP_RETBLEED_UNTRAIN_RET "jmp retbleed_untrain_ret" -#else /* !CONFIG_CPU_UNRET_ENTRY */ +#else /* !CONFIG_MITIGATION_UNRET_ENTRY */ #define JMP_RETBLEED_UNTRAIN_RET "ud2" -#endif /* CONFIG_CPU_UNRET_ENTRY */ +#endif /* CONFIG_MITIGATION_UNRET_ENTRY */ -#if defined(CONFIG_CPU_UNRET_ENTRY) || defined(CONFIG_CPU_SRSO) +#if defined(CONFIG_MITIGATION_UNRET_ENTRY) || defined(CONFIG_MITIGATION_SRSO) SYM_FUNC_START(entry_untrain_ret) ALTERNATIVE JMP_RETBLEED_UNTRAIN_RET, JMP_SRSO_UNTRAIN_RET, X86_FEATURE_SRSO SYM_FUNC_END(entry_untrain_ret) __EXPORT_THUNK(entry_untrain_ret) -#endif /* CONFIG_CPU_UNRET_ENTRY || CONFIG_CPU_SRSO */ +#endif /* CONFIG_MITIGATION_UNRET_ENTRY || CONFIG_MITIGATION_SRSO */ -#ifdef CONFIG_CALL_DEPTH_TRACKING +#ifdef CONFIG_MITIGATION_CALL_DEPTH_TRACKING .align 64 SYM_FUNC_START(call_depth_return_thunk) @@ -364,7 +364,7 @@ SYM_FUNC_START(call_depth_return_thunk) int3 SYM_FUNC_END(call_depth_return_thunk) -#endif /* CONFIG_CALL_DEPTH_TRACKING */ +#endif /* CONFIG_MITIGATION_CALL_DEPTH_TRACKING */ /* * This function name is magical and is used by -mfunction-return=thunk-extern @@ -374,21 +374,25 @@ SYM_FUNC_END(call_depth_return_thunk) * 'JMP __x86_return_thunk' sites are changed to something else by * apply_returns(). * - * This should be converted eventually to call a warning function which - * should scream loudly when the default return thunk is called after - * alternatives have been applied. - * - * That warning function cannot BUG() because the bug splat cannot be - * displayed in all possible configurations, leading to users not really - * knowing why the machine froze. + * The ALTERNATIVE below adds a really loud warning to catch the case + * where the insufficient default return thunk ends up getting used for + * whatever reason like miscompilation or failure of + * objtool/alternatives/etc to patch all the return sites. */ SYM_CODE_START(__x86_return_thunk) UNWIND_HINT_FUNC ANNOTATE_NOENDBR +#if defined(CONFIG_MITIGATION_UNRET_ENTRY) || \ + defined(CONFIG_MITIGATION_SRSO) || \ + defined(CONFIG_MITIGATION_CALL_DEPTH_TRACKING) + ALTERNATIVE __stringify(ANNOTATE_UNRET_SAFE; ret), \ + "jmp warn_thunk_thunk", X86_FEATURE_ALWAYS +#else ANNOTATE_UNRET_SAFE ret +#endif int3 SYM_CODE_END(__x86_return_thunk) EXPORT_SYMBOL(__x86_return_thunk) -#endif /* CONFIG_RETHUNK */ +#endif /* CONFIG_MITIGATION_RETHUNK */ |