From: Rong Tao <rtoax@foxmail.com>
To: mark.rutland@arm.com, elver@google.com, tglx@linutronix.de,
peterz@infradead.org, Rong Tao <rongtao@cestc.cn>,
linux-kernel@vger.kernel.org (open list)
Subject: [PATCH] stop_machine: Avoid potential race behaviour of multi_stop_data::state
Date: Tue, 17 Oct 2023 16:50:52 +0800 [thread overview]
Message-ID: <tencent_705C16DF25978ACAEBD1E83E228881901006@qq.com> (raw)
From: Rong Tao <rongtao@cestc.cn>
In commit b1fc58333575 ("stop_machine: Avoid potential race behaviour")
fix both multi_cpu_stop() and set_state() access multi_stop_data::state,
We should ensure that multi_stop_data::state is accessed using the rwonce
method.
Signed-off-by: Rong Tao <rongtao@cestc.cn>
---
kernel/stop_machine.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/kernel/stop_machine.c b/kernel/stop_machine.c
index cedb17ba158a..73de9ab77132 100644
--- a/kernel/stop_machine.c
+++ b/kernel/stop_machine.c
@@ -191,7 +191,7 @@ static void set_state(struct multi_stop_data *msdata,
static void ack_state(struct multi_stop_data *msdata)
{
if (atomic_dec_and_test(&msdata->thread_ack))
- set_state(msdata, msdata->state + 1);
+ set_state(msdata, READ_ONCE(msdata->state) + 1);
}
notrace void __weak stop_machine_yield(const struct cpumask *cpumask)
--
2.42.0
next reply other threads:[~2023-10-17 8:51 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-10-17 8:50 Rong Tao [this message]
2023-10-17 10:24 ` Mark Rutland
2023-10-17 13:14 ` Peter Zijlstra
2023-10-19 0:13 ` Rong Tao
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=tencent_705C16DF25978ACAEBD1E83E228881901006@qq.com \
--to=rtoax@foxmail.com \
--cc=elver@google.com \
--cc=linux-kernel@vger.kernel.org \
--cc=mark.rutland@arm.com \
--cc=peterz@infradead.org \
--cc=rongtao@cestc.cn \
--cc=tglx@linutronix.de \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox
all inboxes | Powered by JetHome®