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author | Andre Przywara <andre.przywara@arm.com> | 2018-05-11 15:20:12 +0100 |
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committer | Paolo Bonzini <pbonzini@redhat.com> | 2018-05-15 13:36:27 +0200 |
commit | 388d4359680b56dba82fe2ffca05871e9fd2b73e (patch) | |
tree | 547fce672af5345a2a080958dfff6f791cb6fd72 /virt/kvm/arm/vgic/vgic-its.c | |
parent | 4c27625b7a67eb9006963ed2bcf8e53b259b43af (diff) | |
download | linux-stable-388d4359680b56dba82fe2ffca05871e9fd2b73e.tar.gz linux-stable-388d4359680b56dba82fe2ffca05871e9fd2b73e.tar.bz2 linux-stable-388d4359680b56dba82fe2ffca05871e9fd2b73e.zip |
KVM: arm/arm64: Properly protect VGIC locks from IRQs
As Jan reported [1], lockdep complains about the VGIC not being bullet
proof. This seems to be due to two issues:
- When commit 006df0f34930 ("KVM: arm/arm64: Support calling
vgic_update_irq_pending from irq context") promoted irq_lock and
ap_list_lock to _irqsave, we forgot two instances of irq_lock.
lockdeps seems to pick those up.
- If a lock is _irqsave, any other locks we take inside them should be
_irqsafe as well. So the lpi_list_lock needs to be promoted also.
This fixes both issues by simply making the remaining instances of those
locks _irqsave.
One irq_lock is addressed in a separate patch, to simplify backporting.
[1] http://lists.infradead.org/pipermail/linux-arm-kernel/2018-May/575718.html
Cc: stable@vger.kernel.org
Fixes: 006df0f34930 ("KVM: arm/arm64: Support calling vgic_update_irq_pending from irq context")
Reported-by: Jan Glauber <jan.glauber@caviumnetworks.com>
Acked-by: Christoffer Dall <christoffer.dall@arm.com>
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'virt/kvm/arm/vgic/vgic-its.c')
-rw-r--r-- | virt/kvm/arm/vgic/vgic-its.c | 10 |
1 files changed, 6 insertions, 4 deletions
diff --git a/virt/kvm/arm/vgic/vgic-its.c b/virt/kvm/arm/vgic/vgic-its.c index a8f07243aa9f..41abf92f2699 100644 --- a/virt/kvm/arm/vgic/vgic-its.c +++ b/virt/kvm/arm/vgic/vgic-its.c @@ -52,6 +52,7 @@ static struct vgic_irq *vgic_add_lpi(struct kvm *kvm, u32 intid, { struct vgic_dist *dist = &kvm->arch.vgic; struct vgic_irq *irq = vgic_get_irq(kvm, NULL, intid), *oldirq; + unsigned long flags; int ret; /* In this case there is no put, since we keep the reference. */ @@ -71,7 +72,7 @@ static struct vgic_irq *vgic_add_lpi(struct kvm *kvm, u32 intid, irq->intid = intid; irq->target_vcpu = vcpu; - spin_lock(&dist->lpi_list_lock); + spin_lock_irqsave(&dist->lpi_list_lock, flags); /* * There could be a race with another vgic_add_lpi(), so we need to @@ -99,7 +100,7 @@ static struct vgic_irq *vgic_add_lpi(struct kvm *kvm, u32 intid, dist->lpi_list_count++; out_unlock: - spin_unlock(&dist->lpi_list_lock); + spin_unlock_irqrestore(&dist->lpi_list_lock, flags); /* * We "cache" the configuration table entries in our struct vgic_irq's. @@ -315,6 +316,7 @@ static int vgic_copy_lpi_list(struct kvm_vcpu *vcpu, u32 **intid_ptr) { struct vgic_dist *dist = &vcpu->kvm->arch.vgic; struct vgic_irq *irq; + unsigned long flags; u32 *intids; int irq_count, i = 0; @@ -330,7 +332,7 @@ static int vgic_copy_lpi_list(struct kvm_vcpu *vcpu, u32 **intid_ptr) if (!intids) return -ENOMEM; - spin_lock(&dist->lpi_list_lock); + spin_lock_irqsave(&dist->lpi_list_lock, flags); list_for_each_entry(irq, &dist->lpi_list_head, lpi_list) { if (i == irq_count) break; @@ -339,7 +341,7 @@ static int vgic_copy_lpi_list(struct kvm_vcpu *vcpu, u32 **intid_ptr) continue; intids[i++] = irq->intid; } - spin_unlock(&dist->lpi_list_lock); + spin_unlock_irqrestore(&dist->lpi_list_lock, flags); *intid_ptr = intids; return i; |