Re: [RFC PATCH] xen/privcmd: Convert get_user_pages*() to pin_user_pages*()

[Boris Ostrovsky]

On 6/22/20 2:52 PM, Souptick Joarder wrote:
>
> I read the code again. I think, this check is needed to handle a scenario when
> lock_pages() return -ENOSPC. Better to keep this check. Let me post v2 of this
> RFC for a clear view.


Actually, error handling seems to be somewhat broken here. If
lock_pages() returns number of pinned pages then that's what we end up
returning from privcmd_ioctl_dm_op(), all the way to user ioctl(). Which
I don't think is right, we should return proper (negative) error.


Do you mind fixing that we well? Then you should be able to avoid
testing pages in a loop.


-boris