Commit 15483b1a126 (server: Allow calling async_handoff() with status code STATUS_ALERTED., 2022-02-10) introduced the set_async_direct_result handler which calls async_set_initial_status().
However, the async_set_initial_status() call does nothing since async->terminated is set, leaving the async in a confusing state (unknown_status = 1 but pending/completed).
So far, this issue is unlikely to have been a problem in practice for the following reasons:
1. async_set_initial_status() would have unset unknown_status, but it remains set instead. This is usually not a problem, since unknown_status is usually ever read by code paths effectively unreachable for non-device (e.g. socket) asyncs.
It would still potentially allow set_async_direct_result to be called multiple times, but it wouldn't actually happen in practice unless something goes wrong.
2. async_set_initial_status() would have set initial_status; however, it is left with the default value STATUS_PENDING. If the actual status is something other than that, the handler closes the wait handle and async_satisfied (the only real consumer of initial_status) would never be called anyway.
For reasons above, this issue is not effectively observable or testable. Nonetheless, the current code does leave the async object in an inconsistent state.
Fix this by removing the !async->terminated check in async_set_initial_status().
Also, remove assert( async->unknown_status ). The client can now trigger the assert() by calling set_async_direct_result on a device async, thereby causing async_set_initial_status() to be called twice.
Signed-off-by: Jinoh Kang jinoh.kang.kr@gmail.com ---
Notes: v1 -> v2: no changes v2 -> v3: no changes v3 -> v4: reuse async_set_initial_status() per feedback v4 -> v5: - fix typo in commit message (s/realconsumer/real consumer/) - remove assert( async->unknown_status ) in async_set_initial_status() v5 -> v6: no changes v6 -> v7: no changes
server/async.c | 8 ++------ 1 file changed, 2 insertions(+), 6 deletions(-)
diff --git a/server/async.c b/server/async.c index 7d0ff10f7a4..6d663a6a553 100644 --- a/server/async.c +++ b/server/async.c @@ -302,12 +302,8 @@ struct async *create_async( struct fd *fd, struct thread *thread, const async_da * the initial status may be STATUS_PENDING */ void async_set_initial_status( struct async *async, unsigned int status ) { - assert( async->unknown_status ); - if (!async->terminated) - { - async->initial_status = status; - async->unknown_status = 0; - } + async->initial_status = status; + async->unknown_status = 0; }
void set_async_pending( struct async *async )