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authorPeter Zijlstra <peterz@infradead.org>2022-06-27 22:21:17 +0000
committerBorislav Petkov <bp@suse.de>2022-06-29 17:43:41 +0200
commitf43b9876e857c739d407bc56df288b0ebe1a9164 (patch)
tree22fcf2716b615556869c460a71ed3fd9b1393bd6 /arch/x86/include/asm/nospec-branch.h
parent26aae8ccbc1972233afd08fb3f368947c0314265 (diff)
x86/retbleed: Add fine grained Kconfig knobs
Do fine-grained Kconfig for all the various retbleed parts. NOTE: if your compiler doesn't support return thunks this will silently 'upgrade' your mitigation to IBPB, you might not like this. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Borislav Petkov <bp@suse.de>
Diffstat (limited to 'arch/x86/include/asm/nospec-branch.h')
-rw-r--r--arch/x86/include/asm/nospec-branch.h10
1 files changed, 8 insertions, 2 deletions
diff --git a/arch/x86/include/asm/nospec-branch.h b/arch/x86/include/asm/nospec-branch.h
index ccde87e6eabb..bb05ed4f46bd 100644
--- a/arch/x86/include/asm/nospec-branch.h
+++ b/arch/x86/include/asm/nospec-branch.h
@@ -127,6 +127,12 @@
.Lskip_rsb_\@:
.endm
+#ifdef CONFIG_CPU_UNRET_ENTRY
+#define CALL_ZEN_UNTRAIN_RET "call zen_untrain_ret"
+#else
+#define CALL_ZEN_UNTRAIN_RET ""
+#endif
+
/*
* Mitigate RETBleed for AMD/Hygon Zen uarch. Requires KERNEL CR3 because the
* return thunk isn't mapped into the userspace tables (then again, AMD
@@ -139,10 +145,10 @@
* where we have a stack but before any RET instruction.
*/
.macro UNTRAIN_RET
-#ifdef CONFIG_RETPOLINE
+#if defined(CONFIG_CPU_UNRET_ENTRY) || defined(CONFIG_CPU_IBPB_ENTRY)
ANNOTATE_UNRET_END
ALTERNATIVE_2 "", \
- "call zen_untrain_ret", X86_FEATURE_UNRET, \
+ CALL_ZEN_UNTRAIN_RET, X86_FEATURE_UNRET, \
"call entry_ibpb", X86_FEATURE_ENTRY_IBPB
#endif
.endm