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-rw-r--r--arch/s390/kernel/nospec-branch.c12
1 files changed, 11 insertions, 1 deletions
diff --git a/arch/s390/kernel/nospec-branch.c b/arch/s390/kernel/nospec-branch.c
index 18ae7b9c71d6..bdddaae96559 100644
--- a/arch/s390/kernel/nospec-branch.c
+++ b/arch/s390/kernel/nospec-branch.c
@@ -35,6 +35,8 @@ early_param("nospec", nospec_setup_early);
static int __init nospec_report(void)
{
+ if (test_facility(156))
+ pr_info("Spectre V2 mitigation: etokens\n");
if (IS_ENABLED(CC_USING_EXPOLINE) && !nospec_disable)
pr_info("Spectre V2 mitigation: execute trampolines\n");
if (__test_facility(82, S390_lowcore.alt_stfle_fac_list))
@@ -56,7 +58,15 @@ early_param("nospectre_v2", nospectre_v2_setup_early);
void __init nospec_auto_detect(void)
{
- if (IS_ENABLED(CC_USING_EXPOLINE)) {
+ if (test_facility(156)) {
+ /*
+ * The machine supports etokens.
+ * Disable expolines and disable nobp.
+ */
+ if (IS_ENABLED(CC_USING_EXPOLINE))
+ nospec_disable = 1;
+ __clear_facility(82, S390_lowcore.alt_stfle_fac_list);
+ } else if (IS_ENABLED(CC_USING_EXPOLINE)) {
/*
* The kernel has been compiled with expolines.
* Keep expolines enabled and disable nobp.