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authorMarc Zyngier <marc.zyngier@arm.com>2014-07-08 15:09:00 +0400
committerChristoffer Dall <christoffer.dall@linaro.org>2014-09-19 05:45:06 +0400
commit71afaba4a2e98bb7bdeba5078370ab43d46e67a1 (patch)
tree4c5939d5813dac6c14ce62844a5eabfb463c259a
parent7e362919a59e6fc60e08ad1cf0b047291d1ca2e9 (diff)
downloadlinux-71afaba4a2e98bb7bdeba5078370ab43d46e67a1.tar.xz
KVM: ARM: vgic: plug irq injection race
As it stands, nothing prevents userspace from injecting an interrupt before the guest's GIC is actually initialized. This goes unnoticed so far (as everything is pretty much statically allocated), but ends up exploding in a spectacular way once we switch to a more dynamic allocation (the GIC data structure isn't there yet). The fix is to test for the "ready" flag in the VGIC distributor before trying to inject the interrupt. Note that in order to avoid breaking userspace, we have to ignore what is essentially an error. Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Acked-by: Christoffer Dall <christoffer.dall@linaro.org>
-rw-r--r--virt/kvm/arm/vgic.c3
1 files changed, 2 insertions, 1 deletions
diff --git a/virt/kvm/arm/vgic.c b/virt/kvm/arm/vgic.c
index 37fd20d35759..9bdf181a00e2 100644
--- a/virt/kvm/arm/vgic.c
+++ b/virt/kvm/arm/vgic.c
@@ -1585,7 +1585,8 @@ out:
int kvm_vgic_inject_irq(struct kvm *kvm, int cpuid, unsigned int irq_num,
bool level)
{
- if (vgic_update_irq_pending(kvm, cpuid, irq_num, level))
+ if (likely(vgic_initialized(kvm)) &&
+ vgic_update_irq_pending(kvm, cpuid, irq_num, level))
vgic_kick_vcpus(kvm);
return 0;