[PATCH 10/35] KVM: Use kzalloc to avoid allocating kvm_regs from kernel stack

[Avi Kivity]

From: Xiantao Zhang <xiantao.zhang@xxxxxxxxx>

Since the size of kvm_regs is too big to allocate from kernel stack on ia64,
use kzalloc to allocate it.

Signed-off-by: Xiantao Zhang <xiantao.zhang@xxxxxxxxx>
Signed-off-by: Avi Kivity <avi@xxxxxxxxxxxx>
---
 virt/kvm/kvm_main.c |   33 ++++++++++++++++++++++-----------
 1 files changed, 22 insertions(+), 11 deletions(-)

diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 0dabf58..30bf832 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -849,28 +849,39 @@ static long kvm_vcpu_ioctl(struct file *filp,
 		r = kvm_arch_vcpu_ioctl_run(vcpu, vcpu->run);
 		break;
 	case KVM_GET_REGS: {
-		struct kvm_regs kvm_regs;
+		struct kvm_regs *kvm_regs;
 
-		memset(&kvm_regs, 0, sizeof kvm_regs);
-		r = kvm_arch_vcpu_ioctl_get_regs(vcpu, &kvm_regs);
-		if (r)
+		r = -ENOMEM;
+		kvm_regs = kzalloc(sizeof(struct kvm_regs), GFP_KERNEL);
+		if (!kvm_regs)
 			goto out;
+		r = kvm_arch_vcpu_ioctl_get_regs(vcpu, kvm_regs);
+		if (r)
+			goto out_free1;
 		r = -EFAULT;
-		if (copy_to_user(argp, &kvm_regs, sizeof kvm_regs))
-			goto out;
+		if (copy_to_user(argp, kvm_regs, sizeof(struct kvm_regs)))
+			goto out_free1;
 		r = 0;
+out_free1:
+		kfree(kvm_regs);
 		break;
 	}
 	case KVM_SET_REGS: {
-		struct kvm_regs kvm_regs;
+		struct kvm_regs *kvm_regs;
 
-		r = -EFAULT;
-		if (copy_from_user(&kvm_regs, argp, sizeof kvm_regs))
+		r = -ENOMEM;
+		kvm_regs = kzalloc(sizeof(struct kvm_regs), GFP_KERNEL);
+		if (!kvm_regs)
 			goto out;
-		r = kvm_arch_vcpu_ioctl_set_regs(vcpu, &kvm_regs);
+		r = -EFAULT;
+		if (copy_from_user(kvm_regs, argp, sizeof(struct kvm_regs)))
+			goto out_free2;
+		r = kvm_arch_vcpu_ioctl_set_regs(vcpu, kvm_regs);
 		if (r)
-			goto out;
+			goto out_free2;
 		r = 0;
+out_free2:
+		kfree(kvm_regs);
 		break;
 	}
 	case KVM_GET_SREGS: {
-- 
1.5.4.5

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