KVM: fix lock imbalance in kvm_*_irq_source_id()

Stanse found 2 lock imbalances in kvm_request_irq_source_id and kvm_free_irq_source_id. They omit to unlock kvm->irq_lock on fail paths. Fix that by adding unlock labels at the end of the functions and jump there from the fail paths. Signed-off-by: Jiri Slaby <[email protected]> Cc: Marcelo Tosatti <[email protected]> Signed-off-by: Avi Kivity <[email protected]>
mrcsosa · Dec 3, 2009 · 0c6ddce · 0c6ddce
1 parent e935d48
commit 0c6ddce
Showing 1 changed file with 5 additions and 2 deletions.
diff --git a/virt/kvm/irq_comm.c b/virt/kvm/irq_comm.c
@@ -220,11 +220,13 @@ int kvm_request_irq_source_id(struct kvm *kvm)
 
 	if (irq_source_id >= sizeof(kvm->arch.irq_sources_bitmap)) {
 		printk(KERN_WARNING "kvm: exhaust allocatable IRQ sources!\n");
-		return -EFAULT;
+		irq_source_id = -EFAULT;
+		goto unlock;
 	}
 
 	ASSERT(irq_source_id != KVM_USERSPACE_IRQ_SOURCE_ID);
 	set_bit(irq_source_id, bitmap);
+unlock:
 	mutex_unlock(&kvm->irq_lock);
 
 	return irq_source_id;
@@ -240,7 +242,7 @@ void kvm_free_irq_source_id(struct kvm *kvm, int irq_source_id)
 	if (irq_source_id < 0 ||
 	    irq_source_id >= sizeof(kvm->arch.irq_sources_bitmap)) {
 		printk(KERN_ERR "kvm: IRQ source ID out of range!\n");
-		return;
+		goto unlock;
 	}
 	for (i = 0; i < KVM_IOAPIC_NUM_PINS; i++) {
 		clear_bit(irq_source_id, &kvm->arch.vioapic->irq_states[i]);
@@ -251,6 +253,7 @@ void kvm_free_irq_source_id(struct kvm *kvm, int irq_source_id)
 #endif
 	}
 	clear_bit(irq_source_id, &kvm->arch.irq_sources_bitmap);
+unlock:
 	mutex_unlock(&kvm->irq_lock);
 }