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authorJosh Poimboeuf <jpoimboe@kernel.org>2022-06-14 15:07:19 -0700
committerBorislav Petkov <bp@suse.de>2022-06-27 10:34:00 +0200
commit0fe4aeea9c01baabecc8c3afc7889c809d939bc2 (patch)
tree7b2532b4d57abff89e5fd5203ee8743df6dd3aea /arch/x86
parent3ebc170068885b6fc7bedda6c667bb2c4d533159 (diff)
downloadlinux-0fe4aeea9c01baabecc8c3afc7889c809d939bc2.tar.bz2
x86/bugs: Do IBPB fallback check only once
When booting with retbleed=auto, if the kernel wasn't built with CONFIG_CC_HAS_RETURN_THUNK, the mitigation falls back to IBPB. Make sure a warning is printed in that case. The IBPB fallback check is done twice, but it really only needs to be done once. Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org> Signed-off-by: Borislav Petkov <bp@suse.de>
Diffstat (limited to 'arch/x86')
-rw-r--r--arch/x86/kernel/cpu/bugs.c15
1 files changed, 5 insertions, 10 deletions
diff --git a/arch/x86/kernel/cpu/bugs.c b/arch/x86/kernel/cpu/bugs.c
index 04077d13b3ae..108bd74289c5 100644
--- a/arch/x86/kernel/cpu/bugs.c
+++ b/arch/x86/kernel/cpu/bugs.c
@@ -891,18 +891,13 @@ static void __init retbleed_select_mitigation(void)
case RETBLEED_CMD_AUTO:
default:
if (boot_cpu_data.x86_vendor == X86_VENDOR_AMD ||
- boot_cpu_data.x86_vendor == X86_VENDOR_HYGON) {
-
- if (IS_ENABLED(CONFIG_RETPOLINE) &&
- IS_ENABLED(CONFIG_CC_HAS_RETURN_THUNK))
- retbleed_mitigation = RETBLEED_MITIGATION_UNRET;
- else
- retbleed_mitigation = RETBLEED_MITIGATION_IBPB;
- }
+ boot_cpu_data.x86_vendor == X86_VENDOR_HYGON)
+ retbleed_mitigation = RETBLEED_MITIGATION_UNRET;
/*
- * The Intel mitigation (IBRS) was already selected in
- * spectre_v2_select_mitigation().
+ * The Intel mitigation (IBRS or eIBRS) was already selected in
+ * spectre_v2_select_mitigation(). 'retbleed_mitigation' will
+ * be set accordingly below.
*/
break;