linux-kernel - [PATCH] io_uring/sqpoll: Do not set PF_NO

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Date:   Tue, 14 Mar 2023 19:33:32 +0100
From:   Michal Koutný <mkoutny@...e.com>
To:     io-uring@...r.kernel.org
Cc:     linux-kernel@...r.kernel.org, cgroups@...r.kernel.org,
        Jens Axboe <axboe@...nel.dk>,
        Pavel Begunkov <asml.silence@...il.com>,
        Daniel Dao <dqminh@...udflare.com>,
        Waiman Long <longman@...hat.com>
Subject: [PATCH] io_uring/sqpoll: Do not set PF_NO_SETAFFINITY on sqpoll threads

Users may specify a CPU where the sqpoll thread would run. This may
conflict with cpuset operations because of strict PF_NO_SETAFFINITY
requirement. That flag is unnecessary for polling "kernel" threads, see
the reasoning in commit 01e68ce08a30 ("io_uring/io-wq: stop setting
PF_NO_SETAFFINITY on io-wq workers"). Drop the flag on poll threads too.

Fixes: 01e68ce08a30 ("io_uring/io-wq: stop setting PF_NO_SETAFFINITY on io-wq workers")
Link: https://lore.kernel.org/all/20230314162559.pnyxdllzgw7jozgx@blackpad/
Signed-off-by: Michal Koutný <mkoutny@...e.com>
---
 io_uring/sqpoll.c | 1 -
 1 file changed, 1 deletion(-)

diff --git a/io_uring/sqpoll.c b/io_uring/sqpoll.c
index 0119d3f1a556..9db4bc1f521a 100644
--- a/io_uring/sqpoll.c
+++ b/io_uring/sqpoll.c
@@ -233,7 +233,6 @@ static int io_sq_thread(void *data)
 		set_cpus_allowed_ptr(current, cpumask_of(sqd->sq_cpu));
 	else
 		set_cpus_allowed_ptr(current, cpu_online_mask);
-	current->flags |= PF_NO_SETAFFINITY;
 
 	mutex_lock(&sqd->lock);
 	while (1) {
-- 
2.39.2