This is a note to let you know that I've just added the patch titled

KVM: arm/arm64: Fix spinlock acquisition in vgic_set_owner

to the 4.14-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git%3Ba=su...

The filename of the patch is: kvm-arm-arm64-fix-spinlock-acquisition-in-vgic_set_owner.patch and it can be found in the queue-4.14 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let stable@vger.kernel.org know about it.

From foo@baz Fri Feb 23 11:45:09 CET 2018

From: Marc Zyngier marc.zyngier@arm.com Date: Thu, 30 Nov 2017 17:00:30 +0000 Subject: KVM: arm/arm64: Fix spinlock acquisition in vgic_set_owner

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@verizon.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- 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; }

Patches currently in stable-queue which might be from marc.zyngier@arm.com are

queue-4.14/arm-dts-fix-omap4-hang-with-gps-connected-to-usb-by-using-wakeupgen.patch queue-4.14/kvm-arm-don-t-treat-unavailable-hyp-mode-as-an-error.patch queue-4.14/kvm-arm-arm64-fix-spinlock-acquisition-in-vgic_set_owner.patch