[PATCH 0/2] rust: revocable: fix potential race between concurrent revokers

[Danilo Krummrich <dakr@kernel.org>]

Fix a race condition caused by not considering that Revocable does not guarantee
the wrapped object has been fully dropped by the time revoke() or
revoke_nosync() returns false.

There is currently no actual bug caused by this, but it causes SGTable and
Lyude's patch in [1] to be unsound.

Since Completion::new() is infallible but Revocable::new() is generic over the
error type, the first patch adds PinInit::map_err() to bridge the error type
mismatch.

This can either go separately or together with Lyude's patch. Both cases are
unlikely to ever hit this problem, so it should be fine either way.

[1] https://lore.kernel.org/dri-devel/20260612194436.585385-5-lyude@redhat.com/

Danilo Krummrich (2):
  pin-init: add PinInit::map_err() for error type conversion
  rust: revocable: fix race between concurrent revokers

 rust/kernel/revocable.rs | 23 ++++++++++++++++++---
 rust/pin-init/src/lib.rs | 44 ++++++++++++++++++++++++++++++++++++++++
 2 files changed, 64 insertions(+), 3 deletions(-)


base-commit: 66affa37cfac0aec061cc4bcf4a065b0c52f7e19
-- 
2.54.0