KVM: Use kzalloc to avoid allocating kvm_regs from kernel stack

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@intel.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>

diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 31db9b4..41d4b65 100644 (file)
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -852,28 +852,39 @@ 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: {