[GIT PULL] arm/arm64: KVM: Fix unaligned access bug on gicv2 access

Christoffer Dall christoffer.dall at linaro.org
Mon Sep 22 14:12:30 PDT 2014

We were using an atomic bitop on the vgic_v2.vgic_elrsr field which was
not aligned to the natural size on 64-bit platforms.  This bug showed up
after QEMU correctly identifies the pl011 line as being level-triggered,
and not edge-triggered.

These data structures are protected by a spinlock so simply use a
non-atomic version of the accessor instead.

Tested-by: Joel Schopp <joel.schopp at amd.com>
Reported-by: Riku Voipio <riku.voipio at linaro.org>
Signed-off-by: Christoffer Dall <christoffer.dall at linaro.org>
 virt/kvm/arm/vgic-v2.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/virt/kvm/arm/vgic-v2.c b/virt/kvm/arm/vgic-v2.c
index 01124ef..416baed 100644
--- a/virt/kvm/arm/vgic-v2.c
+++ b/virt/kvm/arm/vgic-v2.c
@@ -71,7 +71,7 @@ static void vgic_v2_sync_lr_elrsr(struct kvm_vcpu *vcpu, int lr,
 				  struct vgic_lr lr_desc)
 	if (!(lr_desc.state & LR_STATE_MASK))
-		set_bit(lr, (unsigned long *)vcpu->arch.vgic_cpu.vgic_v2.vgic_elrsr);
+		__set_bit(lr, (unsigned long *)vcpu->arch.vgic_cpu.vgic_v2.vgic_elrsr);
 static u64 vgic_v2_get_elrsr(const struct kvm_vcpu *vcpu)

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