[PATCH 4/5] ARM: KVM: clear exclusive monitor on all exception returns

Marc Zyngier marc.zyngier at arm.com
Wed Jun 19 09:20:05 EDT 2013


Make sure we clear the exclusive movitor on all exception returns,
which otherwise could lead to lock corruptions.

Signed-off-by: Marc Zyngier <marc.zyngier at arm.com>
---
 arch/arm/kvm/interrupts.S | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/arch/arm/kvm/interrupts.S b/arch/arm/kvm/interrupts.S
index 3124e0f..750f051 100644
--- a/arch/arm/kvm/interrupts.S
+++ b/arch/arm/kvm/interrupts.S
@@ -301,6 +301,7 @@ THUMB(	orr	r2, r2, #PSR_T_BIT	)
 	ldr	r2, =BSYM(panic)
 	msr	ELR_hyp, r2
 	ldr	r0, =\panic_str
+	clrex				@ Clear exclusive monitor
 	eret
 .endm
 
@@ -450,6 +451,7 @@ guest_trap:
 
 4:	pop	{r0, r1}		@ Failed translation, return to guest
 	mcrr	p15, 0, r0, r1, c7	@ PAR
+	clrex
 	pop	{r0, r1, r2}
 	eret
 
@@ -476,6 +478,7 @@ switch_to_guest_vfp:
 
 	pop	{r3-r7}
 	pop	{r0-r2}
+	clrex
 	eret
 #endif
 
-- 
1.8.2.3





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