Re: [PATCH v7 1/4] userfaultfd: Add UFFD WP Async support

[Muhammad Usama Anjum]

On 1/24/23 10:26 PM, Peter Xu wrote:
> On Mon, Jan 23, 2023 at 03:11:20PM +0500, Muhammad Usama Anjum wrote:
>>> One thing worth mention is, I think for async wp it doesn't need to be
>>> restricted by UFFD_USER_MODE_ONLY, because comparing to the sync messages
>>> it has no risk of being utilized for malicious purposes.
>> I think with updated handling path updated in do_wp_page() and
>> wp_huge_pmd() in version, UFFD_USER_MODE_ONLY will not affect us.
> 
> This is more or less a comment for the design, the new code should work (by
> bypassing handle_userfaultfd(), where this bit was checked).
> 
> We'll need an man page update if this feature will be merged [1], and if so
> it'll need to be updated for the UFFD_USER_MODE_ONLY section regarding to
> async uffd-wp support too.  I think that can also be worked out after the
> series being accepted first, so just a heads up.
> 
> [1] https://git.kernel.org/pub/scm/docs/man-pages/man-pages.git
Thank you for explaining it. Definitely, we'll update the man pages after
the change has been merged. I've added it to my notes.>

-- 
BR,
Muhammad Usama Anjum