Commit 7465894e authored by Marc Zyngier's avatar Marc Zyngier Committed by Christoffer Dall

KVM: arm/arm64: Fix spinlock acquisition in vgic_set_owner

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: default avatarJames Morse <james.morse@arm.com>
Signed-off-by: default avatarMarc Zyngier <marc.zyngier@arm.com>
Signed-off-by: default avatarChristoffer Dall <christoffer.dall@linaro.org>
parent 58d0d19a
...@@ -492,6 +492,7 @@ int kvm_vgic_unmap_phys_irq(struct kvm_vcpu *vcpu, unsigned int vintid) ...@@ -492,6 +492,7 @@ int kvm_vgic_unmap_phys_irq(struct kvm_vcpu *vcpu, unsigned int vintid)
int kvm_vgic_set_owner(struct kvm_vcpu *vcpu, unsigned int intid, void *owner) int kvm_vgic_set_owner(struct kvm_vcpu *vcpu, unsigned int intid, void *owner)
{ {
struct vgic_irq *irq; struct vgic_irq *irq;
unsigned long flags;
int ret = 0; int ret = 0;
if (!vgic_initialized(vcpu->kvm)) if (!vgic_initialized(vcpu->kvm))
...@@ -502,12 +503,12 @@ int kvm_vgic_set_owner(struct kvm_vcpu *vcpu, unsigned int intid, void *owner) ...@@ -502,12 +503,12 @@ int kvm_vgic_set_owner(struct kvm_vcpu *vcpu, unsigned int intid, void *owner)
return -EINVAL; return -EINVAL;
irq = vgic_get_irq(vcpu->kvm, vcpu, intid); 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) if (irq->owner && irq->owner != owner)
ret = -EEXIST; ret = -EEXIST;
else else
irq->owner = owner; irq->owner = owner;
spin_unlock(&irq->irq_lock); spin_unlock_irqrestore(&irq->irq_lock, flags);
return ret; return ret;
} }
......
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