[PATCH 1/2] x86,paravirt: Fix native_patch()
From: Peter Zijlstra <peterz@infradead.org>
Date: 2016-12-08 15:47:35
Also in:
lkml
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@infradead.org>
---
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;