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Commit fa3795a7 authored by Dave Hansen's avatar Dave Hansen Committed by Avi Kivity
Browse files

KVM: Reduce stack usage in kvm_vcpu_ioctl() 



Signed-off-by: default avatarDave Hansen <dave@linux.vnet.ibm.com>
Signed-off-by: default avatarAvi Kivity <avi@qumranet.com>
parent f0d66275

virt/kvm/kvm_main.c

+28 −18
Original line number Diff line number Diff line
@@ -1126,6 +1126,8 @@ static long kvm_vcpu_ioctl(struct file *filp, 
	struct kvm_vcpu *vcpu = filp->private_data;

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

	int r;

	struct kvm_fpu *fpu = NULL;

	struct kvm_sregs *kvm_sregs = NULL;



	if (vcpu->kvm->mm != current->mm)

		return -EIO;
@@ -1173,25 +1175,28 @@ static long kvm_vcpu_ioctl(struct file *filp, 
		break;

	}

	case KVM_GET_SREGS: {

		struct kvm_sregs kvm_sregs;



		memset(&kvm_sregs, 0, sizeof kvm_sregs);

		r = kvm_arch_vcpu_ioctl_get_sregs(vcpu, &kvm_sregs);

		kvm_sregs = kzalloc(sizeof(struct kvm_sregs), GFP_KERNEL);

		r = -ENOMEM;

		if (!kvm_sregs)

			goto out;

		r = kvm_arch_vcpu_ioctl_get_sregs(vcpu, kvm_sregs);

		if (r)

			goto out;

		r = -EFAULT;

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

		if (copy_to_user(argp, kvm_sregs, sizeof(struct kvm_sregs)))

			goto out;

		r = 0;

		break;

	}

	case KVM_SET_SREGS: {

		struct kvm_sregs kvm_sregs;



		kvm_sregs = kmalloc(sizeof(struct kvm_sregs), GFP_KERNEL);

		r = -ENOMEM;

		if (!kvm_sregs)

			goto out;

		r = -EFAULT;

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

		if (copy_from_user(kvm_sregs, argp, sizeof(struct kvm_sregs)))

			goto out;

		r = kvm_arch_vcpu_ioctl_set_sregs(vcpu, &kvm_sregs);

		r = kvm_arch_vcpu_ioctl_set_sregs(vcpu, kvm_sregs);

		if (r)

			goto out;

		r = 0;
@@ -1272,25 +1277,28 @@ static long kvm_vcpu_ioctl(struct file *filp, 
		break;

	}

	case KVM_GET_FPU: {

		struct kvm_fpu fpu;



		memset(&fpu, 0, sizeof fpu);

		r = kvm_arch_vcpu_ioctl_get_fpu(vcpu, &fpu);

		fpu = kzalloc(sizeof(struct kvm_fpu), GFP_KERNEL);

		r = -ENOMEM;

		if (!fpu)

			goto out;

		r = kvm_arch_vcpu_ioctl_get_fpu(vcpu, fpu);

		if (r)

			goto out;

		r = -EFAULT;

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

		if (copy_to_user(argp, fpu, sizeof(struct kvm_fpu)))

			goto out;

		r = 0;

		break;

	}

	case KVM_SET_FPU: {

		struct kvm_fpu fpu;



		fpu = kmalloc(sizeof(struct kvm_fpu), GFP_KERNEL);

		r = -ENOMEM;

		if (!fpu)

			goto out;

		r = -EFAULT;

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

		if (copy_from_user(fpu, argp, sizeof(struct kvm_fpu)))

			goto out;

		r = kvm_arch_vcpu_ioctl_set_fpu(vcpu, &fpu);

		r = kvm_arch_vcpu_ioctl_set_fpu(vcpu, fpu);

		if (r)

			goto out;

		r = 0;
@@ -1300,6 +1308,8 @@ static long kvm_vcpu_ioctl(struct file *filp, 
		r = kvm_arch_vcpu_ioctl(filp, ioctl, arg);

	}

out:

	kfree(fpu);

	kfree(kvm_sregs);

	return r;

}