x86/nospec: Refactor UNTRAIN_RET[_*]

Factor out the UNTRAIN_RET[_*] common bits into a helper macro.

Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Acked-by: Borislav Petkov (AMD) <bp@alien8.de>
Link: https://lore.kernel.org/r/f06d45489778bd49623297af2a983eea09067a74.1693889988.git.jpoimboe@kernel.org

diff --git a/arch/x86/include/asm/nospec-branch.h b/arch/x86/include/asm/nospec-branch.h
index 51e3f1a287d2f006dc183be31b7a967d5b9f5315..dcc78477a38d85395f4a65442aaa480892f4483a 100644 (file)
--- a/arch/x86/include/asm/nospec-branch.h
+++ b/arch/x86/include/asm/nospec-branch.h
@@ -288,35 +288,24 @@
  * As such, this must be placed after every *SWITCH_TO_KERNEL_CR3 at a point
  * where we have a stack but before any RET instruction.
  */
-.macro UNTRAIN_RET
+.macro __UNTRAIN_RET ibpb_feature, call_depth_insns
 #if defined(CONFIG_RETHUNK) || defined(CONFIG_CPU_IBPB_ENTRY)
        VALIDATE_UNRET_END
        ALTERNATIVE_3 "",                                               \
                      CALL_UNTRAIN_RET, X86_FEATURE_UNRET,              \
-                     "call entry_ibpb", X86_FEATURE_ENTRY_IBPB,        \
-                    __stringify(RESET_CALL_DEPTH), X86_FEATURE_CALL_DEPTH
+                     "call entry_ibpb", \ibpb_feature,                 \
+                    __stringify(\call_depth_insns), X86_FEATURE_CALL_DEPTH
 #endif
 .endm
 
-.macro UNTRAIN_RET_VM
-#if defined(CONFIG_RETHUNK) || defined(CONFIG_CPU_IBPB_ENTRY)
-       VALIDATE_UNRET_END
-       ALTERNATIVE_3 "",                                               \
-                     CALL_UNTRAIN_RET, X86_FEATURE_UNRET,              \
-                     "call entry_ibpb", X86_FEATURE_IBPB_ON_VMEXIT,    \
-                     __stringify(RESET_CALL_DEPTH), X86_FEATURE_CALL_DEPTH
-#endif
-.endm
+#define UNTRAIN_RET \
+       __UNTRAIN_RET X86_FEATURE_ENTRY_IBPB, __stringify(RESET_CALL_DEPTH)
 
-.macro UNTRAIN_RET_FROM_CALL
-#if defined(CONFIG_RETHUNK) || defined(CONFIG_CPU_IBPB_ENTRY)
-       VALIDATE_UNRET_END
-       ALTERNATIVE_3 "",                                               \
-                     CALL_UNTRAIN_RET, X86_FEATURE_UNRET,              \
-                     "call entry_ibpb", X86_FEATURE_ENTRY_IBPB,        \
-                     __stringify(RESET_CALL_DEPTH_FROM_CALL), X86_FEATURE_CALL_DEPTH
-#endif
-.endm
+#define UNTRAIN_RET_VM \
+       __UNTRAIN_RET X86_FEATURE_IBPB_ON_VMEXIT, __stringify(RESET_CALL_DEPTH)
+
+#define UNTRAIN_RET_FROM_CALL \
+       __UNTRAIN_RET X86_FEATURE_ENTRY_IBPB, __stringify(RESET_CALL_DEPTH_FROM_CALL)
 
 
 .macro CALL_DEPTH_ACCOUNT