[LTP] userfaultfd: Add helper for checking UFFD feature support

[Andrea Cervesato]

Hi!

> > +	uffd = SAFE_USERFAULTFD(O_CLOEXEC | O_NONBLOCK, false);
> > +
> > +	uffdio_api.api = UFFD_API;
> > +	SAFE_IOCTL(uffd, UFFDIO_API, &uffdio_api);
> 
> If SAFE_IOCTL calls tst_brk(TBROK) here, the local `uffd` is not
> closed before the test runner takes over; the cleanup functions only
> track the global `uffd`. Close it before the SAFE_IOCTL call, or
> restructure to guarantee SAFE_CLOSE on all exit paths.

This is not necessarily wrong, but since TBROK is called, fd is closed
with the process. We need to instruct the agent because I seen this
logical concept being missed a few times.

> 
> --- [PATCH 2/3] ---
> 
> On Thu, 7 May 2026 14:28:54 +0200, Ricardo Branco wrote:
> > [PATCH 2/3] userfaultfd: Use two-step handshake to probe features
> 
> > Fixes: 1840ee23d172b5ab04cca7c2acfa48755b041911
> 
> This commit is not reachable in the local git history (grafted shallow
> clone). Please verify the Fixes: tag resolves correctly against the
> upstream LTP tree.

Can you please double check this? Maybe we have an another issue
with the agent.

Regards,
--
Andrea Cervesato
SUSE QE Automation Engineer Linux
andrea.cervesato@suse.com