x86/bugs: Fix the SRSO mitigation on Zen3/4

[thirdparty/linux.git] / arch / x86 / lib / retpoline.S

diff --git a/arch/x86/lib/retpoline.S b/arch/x86/lib/retpoline.S
index 721b528da9acee3e4eb2168bbd65ab7303a4db3a..02cde194a99e691c54b6252a31b3d9ca7f8e7e42 100644 (file)
--- a/arch/x86/lib/retpoline.S
+++ b/arch/x86/lib/retpoline.S
@@ -163,6 +163,7 @@ SYM_CODE_START_NOALIGN(srso_alias_untrain_ret)
        lfence
        jmp srso_alias_return_thunk
 SYM_FUNC_END(srso_alias_untrain_ret)
+__EXPORT_THUNK(srso_alias_untrain_ret)
        .popsection
 
        .pushsection .text..__x86.rethunk_safe
@@ -224,10 +225,12 @@ SYM_CODE_START(srso_return_thunk)
 SYM_CODE_END(srso_return_thunk)
 
 #define JMP_SRSO_UNTRAIN_RET "jmp srso_untrain_ret"
-#define JMP_SRSO_ALIAS_UNTRAIN_RET "jmp srso_alias_untrain_ret"
 #else /* !CONFIG_MITIGATION_SRSO */
+/* Dummy for the alternative in CALL_UNTRAIN_RET. */
+SYM_CODE_START(srso_alias_untrain_ret)
+       RET
+SYM_FUNC_END(srso_alias_untrain_ret)
 #define JMP_SRSO_UNTRAIN_RET "ud2"
-#define JMP_SRSO_ALIAS_UNTRAIN_RET "ud2"
 #endif /* CONFIG_MITIGATION_SRSO */
 
 #ifdef CONFIG_MITIGATION_UNRET_ENTRY
@@ -319,9 +322,7 @@ SYM_FUNC_END(retbleed_untrain_ret)
 #if defined(CONFIG_MITIGATION_UNRET_ENTRY) || defined(CONFIG_MITIGATION_SRSO)
 
 SYM_FUNC_START(entry_untrain_ret)
-       ALTERNATIVE_2 JMP_RETBLEED_UNTRAIN_RET,                         \
-                     JMP_SRSO_UNTRAIN_RET, X86_FEATURE_SRSO,           \
-                     JMP_SRSO_ALIAS_UNTRAIN_RET, X86_FEATURE_SRSO_ALIAS
+       ALTERNATIVE JMP_RETBLEED_UNTRAIN_RET, JMP_SRSO_UNTRAIN_RET, X86_FEATURE_SRSO
 SYM_FUNC_END(entry_untrain_ret)
 __EXPORT_THUNK(entry_untrain_ret)