diff options
| author | Jens Axboe <axboe@kernel.dk> | 2023-01-21 06:50:24 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2023-01-24 09:19:56 +0300 |
| commit | 2fd232bbd66fafdf7af3cc155c7bb82d96d07bc9 (patch) | |
| tree | 1fb8888bdedb3884ed530ed76a2e03088f13ff31 /io_uring/io-wq.c | |
| parent | e84ec6e25df9bb0968599e92eacedaf3a0a5b587 (diff) | |
| download | linux-2fd232bbd66fafdf7af3cc155c7bb82d96d07bc9.tar.xz | |
io_uring: don't gate task_work run on TIF_NOTIFY_SIGNAL
commit 46a525e199e4037516f7e498c18f065b09df32ac upstream.
This isn't a reliable mechanism to tell if we have task_work pending, we
really should be looking at whether we have any items queued. This is
problematic if forward progress is gated on running said task_work. One
such example is reading from a pipe, where the write side has been closed
right before the read is started. The fput() of the file queues TWA_RESUME
task_work, and we need that task_work to be run before ->release() is
called for the pipe. If ->release() isn't called, then the read will sit
forever waiting on data that will never arise.
Fix this by io_run_task_work() so it checks if we have task_work pending
rather than rely on TIF_NOTIFY_SIGNAL for that. The latter obviously
doesn't work for task_work that is queued without TWA_SIGNAL.
Reported-by: Christiano Haesbaert <haesbaert@haesbaert.org>
Cc: stable@vger.kernel.org
Link: https://github.com/axboe/liburing/issues/665
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'io_uring/io-wq.c')
| -rw-r--r-- | io_uring/io-wq.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/io_uring/io-wq.c b/io_uring/io-wq.c index 87bc38b47103..81485c1a9879 100644 --- a/io_uring/io-wq.c +++ b/io_uring/io-wq.c @@ -513,7 +513,7 @@ static struct io_wq_work *io_get_next_work(struct io_wqe_acct *acct, static bool io_flush_signals(void) { - if (unlikely(test_thread_flag(TIF_NOTIFY_SIGNAL))) { + if (test_thread_flag(TIF_NOTIFY_SIGNAL) || current->task_works) { __set_current_state(TASK_RUNNING); tracehook_notify_signal(); return true; |