On 11/3/24 22:18, Jens Axboe wrote:
On 11/3/24 3:05 PM, Pavel Begunkov wrote:
On 11/3/24 21:54, Jens Axboe wrote:
On 11/3/24 2:47 PM, Pavel Begunkov wrote:
On 11/3/24 17:49, Jens Axboe wrote:
...
diff --git a/include/linux/io_uring/cmd.h b/include/linux/io_uring/cmd.h
...
nd->head = prev_nd->head;
@@ -115,7 +115,7 @@ struct io_kiocb *io_alloc_notif(struct io_ring_ctx *ctx)
notif->opcode = IORING_OP_NOP;
notif->flags = 0;
notif->file = NULL;
- notif->task = current;
+ notif->tctx = current->io_uring;
io_get_task_refs(1);
notif->file_node = NULL;
notif->buf_node = NULL;
diff --git a/io_uring/poll.c b/io_uring/poll.c
index 7db3010b5733..56332893a4b0 100644
--- a/io_uring/poll.c
+++ b/io_uring/poll.c
@@ -224,8 +224,7 @@ static int io_poll_check_events(struct io_kiocb *req, struct io_tw_state *ts)
{
int v;
- /* req->task == current here, checking PF_EXITING is safe */
- if (unlikely(req->task->flags & PF_EXITING))
+ if (unlikely(current->flags & PF_EXITING))
return -ECANCELED
Unlike what the comment says, req->task doesn't have to match current,
in which case the new check does nothing and it'll break in many very
interesting ways.
In which cases does it not outside of fallback?
I think it can only be fallback path
I think so too, that's what I was getting at. Hence I think we should just
change these PF_EXITING checks to be PF_KTHREAD instead. If we're invoked
from that kind of context, cancel.
Replacing with just a PF_KTHREAD check won't be right, you can
get here with the right task but after it has been half killed and
marked PF_EXITING.
--
Pavel Begunkov
