From: Marc Zyngier marc.zyngier@arm.com
[ Upstream commit 7465894e90e5a47e0e52aa5f1f708653fc40020f ]
vgic_set_owner acquires the irq lock without disabling interrupts, resulting in a lockdep splat (an interrupt could fire and result in the same lock being taken if the same virtual irq is to be injected).
In practice, it is almost impossible to trigger this bug, but better safe than sorry. Convert the lock acquisition to a spin_lock_irqsave() and keep lockdep happy.
Reported-by: James Morse james.morse@arm.com Signed-off-by: Marc Zyngier marc.zyngier@arm.com Signed-off-by: Christoffer Dall christoffer.dall@linaro.org Signed-off-by: Sasha Levin alexander.levin@microsoft.com --- virt/kvm/arm/vgic/vgic.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/virt/kvm/arm/vgic/vgic.c b/virt/kvm/arm/vgic/vgic.c index fed717e07938..da53c6e7d688 100644 --- a/virt/kvm/arm/vgic/vgic.c +++ b/virt/kvm/arm/vgic/vgic.c @@ -454,6 +454,7 @@ int kvm_vgic_unmap_phys_irq(struct kvm_vcpu *vcpu, unsigned int virt_irq) int kvm_vgic_set_owner(struct kvm_vcpu *vcpu, unsigned int intid, void *owner) { struct vgic_irq *irq; + unsigned long flags; int ret = 0;
if (!vgic_initialized(vcpu->kvm)) @@ -464,12 +465,12 @@ int kvm_vgic_set_owner(struct kvm_vcpu *vcpu, unsigned int intid, void *owner) return -EINVAL;
irq = vgic_get_irq(vcpu->kvm, vcpu, intid); - spin_lock(&irq->irq_lock); + spin_lock_irqsave(&irq->irq_lock, flags); if (irq->owner && irq->owner != owner) ret = -EEXIST; else irq->owner = owner; - spin_unlock(&irq->irq_lock); + spin_unlock_irqrestore(&irq->irq_lock, flags);
return ret; }