Commit 269e05e4 authored by Avi Kivity's avatar Avi Kivity
Browse files

KVM: Properly lock PIT creation 



Otherwise, two threads can create a PIT in parallel and cause a memory leak.

Signed-off-by: default avatarAvi Kivity <avi@redhat.com>
parent a77ab5ea

arch/x86/kvm/i8254.c

+0 −2
Original line number Diff line number Diff line
@@ -548,9 +548,7 @@ struct kvm_pit *kvm_create_pit(struct kvm *kvm) 
	if (!pit)

		return NULL;



	mutex_lock(&kvm->lock);

	pit->irq_source_id = kvm_request_irq_source_id(kvm);

	mutex_unlock(&kvm->lock);

	if (pit->irq_source_id < 0) {

		kfree(pit);

		return NULL;

arch/x86/kvm/x86.c

+6 −0
Original line number Diff line number Diff line
@@ -1837,10 +1837,16 @@ long kvm_arch_vm_ioctl(struct file *filp, 
			goto out;

		break;

	case KVM_CREATE_PIT:

		mutex_lock(&kvm->lock);

		r = -EEXIST;

		if (kvm->arch.vpit)

			goto create_pit_unlock;

		r = -ENOMEM;

		kvm->arch.vpit = kvm_create_pit(kvm);

		if (kvm->arch.vpit)

			r = 0;

	create_pit_unlock:

		mutex_unlock(&kvm->lock);

		break;

	case KVM_IRQ_LINE: {

		struct kvm_irq_level irq_event;