[PATCH 30/35] KVM: only clear irq_source_id if irqchip is present

Avi Kivity
2009-11-19T13:35:08Z

From: Marcelo Tosatti <mtosatti@redhat.com>

Otherwise kvm might attempt to dereference a NULL pointer.

Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
---
virt/kvm/irq_comm.c | 5 ++++-
1 files changed, 4 insertions(+), 1 deletions(-)

diff --git a/virt/kvm/irq_comm.c b/virt/kvm/irq_comm.c
index 0d454d3..9b07734 100644
--- a/virt/kvm/irq_comm.c
+++ b/virt/kvm/irq_comm.c
@@ -243,6 +243,10 @@ void kvm_free_irq_source_id(struct kvm *kvm, int irq_source_id)
printk(KERN_ERR "kvm: IRQ source ID out of range!\n");
goto unlock;
}
+ clear_bit(irq_source_id, &kvm->arch.irq_sources_bitmap);
+ if (!irqchip_in_kernel(kvm))
+ goto unlock;
+
for (i = 0; i < KVM_IOAPIC_NUM_PINS; i++) {
clear_bit(irq_source_id, &kvm->arch.vioapic->irq_states[i]);
if (i >= 16)
@@ -251,7 +255,6 @@ void kvm_free_irq_source_id(struct kvm *kvm, int irq_source_id)
clear_bit(irq_source_id, &pic_irqchip(kvm)->irq_states[i]);
#endif
}
- clear_bit(irq_source_id, &kvm->arch.irq_sources_bitmap);
unlock:
mutex_unlock(&kvm->irq_lock);
}
--
1.6.5.2