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Commit b772ff36 authored by Dave Hansen's avatar Dave Hansen Committed by Avi Kivity
Browse files

KVM: Reduce stack usage in kvm_arch_vcpu_ioctl() 



[sheng: fix KVM_GET_LAPIC using wrong size]

Signed-off-by: default avatarDave Hansen <dave@linux.vnet.ibm.com>
Signed-off-by: default avatarSheng Yang <sheng.yang@intel.com>
Signed-off-by: default avatarAvi Kivity <avi@qumranet.com>
parent fa3795a7

arch/x86/kvm/x86.c

+15 −8
Original line number Diff line number Diff line
@@ -1542,28 +1542,33 @@ long kvm_arch_vcpu_ioctl(struct file *filp, 
	struct kvm_vcpu *vcpu = filp->private_data;

	void __user *argp = (void __user *)arg;

	int r;

	struct kvm_lapic_state *lapic = NULL;



	switch (ioctl) {

	case KVM_GET_LAPIC: {

		struct kvm_lapic_state lapic;

		lapic = kzalloc(sizeof(struct kvm_lapic_state), GFP_KERNEL);



		memset(&lapic, 0, sizeof lapic);

		r = kvm_vcpu_ioctl_get_lapic(vcpu, &lapic);

		r = -ENOMEM;

		if (!lapic)

			goto out;

		r = kvm_vcpu_ioctl_get_lapic(vcpu, lapic);

		if (r)

			goto out;

		r = -EFAULT;

		if (copy_to_user(argp, &lapic, sizeof lapic))

		if (copy_to_user(argp, lapic, sizeof(struct kvm_lapic_state)))

			goto out;

		r = 0;

		break;

	}

	case KVM_SET_LAPIC: {

		struct kvm_lapic_state lapic;



		lapic = kmalloc(sizeof(struct kvm_lapic_state), GFP_KERNEL);

		r = -ENOMEM;

		if (!lapic)

			goto out;

		r = -EFAULT;

		if (copy_from_user(&lapic, argp, sizeof lapic))

		if (copy_from_user(lapic, argp, sizeof(struct kvm_lapic_state)))

			goto out;

		r = kvm_vcpu_ioctl_set_lapic(vcpu, &lapic);;

		r = kvm_vcpu_ioctl_set_lapic(vcpu, lapic);

		if (r)

			goto out;

		r = 0;
@@ -1661,6 +1666,8 @@ long kvm_arch_vcpu_ioctl(struct file *filp, 
		r = -EINVAL;

	}

out:

	if (lapic)

		kfree(lapic);

	return r;

}