On 1/22/23 13:13, gregkh@xxxxxxxxxxxxxxxxxxx wrote:
The patch below does not apply to the 6.1-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@xxxxxxxxxxxxxxx>.
Apparently, it's not needed in stable
[...]
------------------ original commit in Linus's tree ------------------
From 56d8e3180c065c9b78ed77afcd0cf99677a4e22f Mon Sep 17 00:00:00 2001
From: Pavel Begunkov <asml.silence@xxxxxxxxx>
Date: Fri, 20 Jan 2023 16:38:05 +0000
Subject: [PATCH] io_uring/msg_ring: fix flagging remote execution
There is a couple of problems with queueing a tw in io_msg_ring_data()
for remote execution. First, once we queue it the target ring can
go away and so setting IORING_SQ_TASKRUN there is not safe. Secondly,
the userspace might not expect IORING_SQ_TASKRUN.
Extract a helper and uniformly use TWA_SIGNAL without TWA_SIGNAL_NO_IPI
tricks for now, just as it was done in the original patch.
Cc: stable@xxxxxxxxxxxxxxx
Fixes: 6d043ee1164ca ("io_uring: do msg_ring in target task via tw")
Signed-off-by: Pavel Begunkov <asml.silence@xxxxxxxxx>
Signed-off-by: Jens Axboe <axboe@xxxxxxxxx>
--
Pavel Begunkov
