Re: [PATCH RFC v2 6/6] KVM: introduce a new API for getting dirty bitmaps

Fernando Luis Vázquez Cao
2010-04-21T08:29:49Z

On 04/20/2010 08:03 PM, Takuya Yoshikawa wrote:
> @@ -318,7 +318,7 @@ struct kvm_dirty_log {
> __u32 padding1;
> union {
> void __user *dirty_bitmap; /* one bit per page */
> - __u64 padding2;
> + __u64 addr;

This can break on x86_32 and x86_64-compat. addr is a long not a __u64.

> + case KVM_SWITCH_DIRTY_LOG: {
> + struct kvm_dirty_log log;
> +
> + r = -EFAULT;
> + if (copy_from_user(&log, argp, sizeof log))
> + goto out;
> + r = kvm_vm_ioctl_switch_dirty_log(kvm, &log);
> + if (r)
> + goto out;
> + r = -EFAULT;
> + if (copy_to_user(argp, &log, sizeof log))
> + goto out;
> + r = 0;
> + break;
> + }

In x86_64-compat mode we are handling 32bit user-space addresses
so we need the compat counterpart of KVM_SWITCH_DIRTY_LOG too.