[PATCH 24/46] mm/userfaultfd: wake all waiters on unregister

[sashiko-bot at kernel.org]

> From: Josef Bacik <josef at toxicpanda.com>
> 
> UFFDIO_UNREGISTER only wakes pending faults if VM_UFFD_MISSING is set.
> Threads waiting on write-protect, minor or RWP faults can therefore remain
> asleep after unregistering a range that does not track missing faults.
> 
> Wake pending faults regardless of the registration mode so they can retry
> without an explicit UFFDIO_WAKE or closing the userfaultfd. This matches
> the existing behavior for missing faults, including removing unread fault
> messages for the woken waiters.
> 
> Fix generated by an LLM and sent by Josef Bacik in private.
> 
> Fixes: 63b2d4174c4a ("userfaultfd: wp: add the writeprotect API to userfaultfd ioctl")
> Cc: stable at vger.kernel.org
> Signed-off-by: Josef Bacik <josef at toxicpanda.com>
> [ david: rebase; simplify description ]
> Signed-off-by: David Hildenbrand (Arm) <david at kernel.org>

Sashiko has reviewed this patch and found no issues.

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Sashiko AI review · https://sashiko.dev/#/patchset/20261027-fixes_core-v1-0-6f74bec9a5bb@kernel.org?part=24