While chasing a regression I noticed we potentially patch the wrong
code in native_patch().
If we do not select the native code sequence, we must use the default
patcher, not fall-through the switch case.
Fixes: 3cded4179481 ("x86/paravirt: Optimize native pv_lock_ops.vcpu_is_preempted()")
Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
---
arch/x86/kernel/paravirt_patch_32.c | 4 ++++
arch/x86/kernel/paravirt_patch_64.c | 4 ++++
2 files changed, 8 insertions(+)
--- a/arch/x86/kernel/paravirt_patch_32.c
+++ b/arch/x86/kernel/paravirt_patch_32.c
@@ -56,15 +56,19 @@ unsigned native_patch(u8 type, u16 clobb
end = end_pv_lock_ops_queued_spin_unlock;
goto patch_site;
}
+ goto patch_default;
+
case PARAVIRT_PATCH(pv_lock_ops.vcpu_is_preempted):
if (pv_is_native_vcpu_is_preempted()) {
start = start_pv_lock_ops_vcpu_is_preempted;
end = end_pv_lock_ops_vcpu_is_preempted;
goto patch_site;
}
+ goto patch_default;
#endif
default:
+patch_default:
ret = paravirt_patch_default(type, clobbers, ibuf, addr, len);
break;
--- a/arch/x86/kernel/paravirt_patch_64.c
+++ b/arch/x86/kernel/paravirt_patch_64.c
@@ -68,15 +68,19 @@ unsigned native_patch(u8 type, u16 clobb
end = end_pv_lock_ops_queued_spin_unlock;
goto patch_site;
}
+ goto patch_default;
+
case PARAVIRT_PATCH(pv_lock_ops.vcpu_is_preempted):
if (pv_is_native_vcpu_is_preempted()) {
start = start_pv_lock_ops_vcpu_is_preempted;
end = end_pv_lock_ops_vcpu_is_preempted;
goto patch_site;
}
+ goto patch_default;
#endif
default:
+patch_default:
ret = paravirt_patch_default(type, clobbers, ibuf, addr, len);
break;
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