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-rw-r--r--arch/x86/lib/retpoline.S46
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 */