4.14-stable review patch. If anyone has any objections, please let me know.
------------------ From: Marc Zyngier <[email protected]> [ 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 <[email protected]> Signed-off-by: Marc Zyngier <[email protected]> Signed-off-by: Christoffer Dall <[email protected]> Signed-off-by: Sasha Levin <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]> --- virt/kvm/arm/vgic/vgic.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) --- 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_v 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 * 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; }
