io_uring/sqpoll: early exit thread if task_context wasn't allocated

Ideally we'd want to simply kill the task rather than wake it, but for
now let's just add a startup check that causes the thread to exit.
This can only happen if io_uring_alloc_task_context() fails, which
generally requires fault injection.

Reported-by: Ubisectech Sirius <bugreport@ubisectech.com>
Fixes: af5d68f8892f ("io_uring/sqpoll: manage task_work privately")
Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/io_uring/sqpoll.c b/io_uring/sqpoll.c
index 363052b4ea76a218f2266f543203631a08d0502b..3983708cef5b431789e0dee10592b73952f7a4e5 100644 (file)
--- a/io_uring/sqpoll.c
+++ b/io_uring/sqpoll.c
@@ -274,6 +274,10 @@ static int io_sq_thread(void *data)
        char buf[TASK_COMM_LEN];
        DEFINE_WAIT(wait);
 
+       /* offload context creation failed, just exit */
+       if (!current->io_uring)
+               goto err_out;
+
        snprintf(buf, sizeof(buf), "iou-sqp-%d", sqd->task_pid);
        set_task_comm(current, buf);
 
@@ -371,7 +375,7 @@ static int io_sq_thread(void *data)
                atomic_or(IORING_SQ_NEED_WAKEUP, &ctx->rings->sq_flags);
        io_run_task_work();
        mutex_unlock(&sqd->lock);
-
+err_out:
        complete(&sqd->exited);
        do_exit(0);
 }