Re: [PATCH] io_uring/rsrc: don't lock while !TASK_RUNNING

[Jens Axboe <axboe@kernel.dk>]

On Wed, 12 Jun 2024 13:56:38 +0100, Pavel Begunkov wrote:
> There is a report of io_rsrc_ref_quiesce() locking a mutex while not
> TASK_RUNNING, which is due to forgetting restoring the state back after
> io_run_task_work_sig() and attempts to break out of the waiting loop.
> 
> do not call blocking ops when !TASK_RUNNING; state=1 set at
> [<ffffffff815d2494>] prepare_to_wait+0xa4/0x380
> kernel/sched/wait.c:237
> WARNING: CPU: 2 PID: 397056 at kernel/sched/core.c:10099
> __might_sleep+0x114/0x160 kernel/sched/core.c:10099
> RIP: 0010:__might_sleep+0x114/0x160 kernel/sched/core.c:10099
> Call Trace:
>  <TASK>
>  __mutex_lock_common kernel/locking/mutex.c:585 [inline]
>  __mutex_lock+0xb4/0x940 kernel/locking/mutex.c:752
>  io_rsrc_ref_quiesce+0x590/0x940 io_uring/rsrc.c:253
>  io_sqe_buffers_unregister+0xa2/0x340 io_uring/rsrc.c:799
>  __io_uring_register io_uring/register.c:424 [inline]
>  __do_sys_io_uring_register+0x5b9/0x2400 io_uring/register.c:613
>  do_syscall_x64 arch/x86/entry/common.c:52 [inline]
>  do_syscall_64+0xd8/0x270 arch/x86/entry/common.c:83
>  entry_SYSCALL_64_after_hwframe+0x6f/0x77
> 
> [...]

Applied, thanks!

[1/1] io_uring/rsrc: don't lock while !TASK_RUNNING
      commit: 54559642b96116b45e4b5ca7fd9f7835b8561272

Best regards,
-- 
Jens Axboe