From: Matthew Wilcox <willy@infradead.org>
To: Zhouyi Zhou <zhouzhouyi@gmail.com>
Cc: paulmck@kernel.org,
Oleksandr Natalenko <oleksandr@natalenko.name>,
linux-kernel <linux-kernel@vger.kernel.org>,
stable@vger.kernel.org, Chris Clayton <chris2553@googlemail.com>,
Chris Rankin <rankincj@gmail.com>,
Josh Triplett <josh@joshtriplett.org>,
Steven Rostedt <rostedt@goodmis.org>,
Mathieu Desnoyers <mathieu.desnoyers@efficios.com>,
Lai Jiangshan <jiangshanlai@gmail.com>,
Joel Fernandes <joel@joelfernandes.org>,
rcu <rcu@vger.kernel.org>,
Andrew Morton <akpm@linux-foundation.org>,
Linux-MM <linux-mm@kvack.org>
Subject: Re: linux-5.13.2: warning from kernel/rcu/tree_plugin.h:359
Date: Mon, 19 Jul 2021 03:43:00 +0100 [thread overview]
Message-ID: <YPTmtNMJpykEpzx6@casper.infradead.org> (raw)
In-Reply-To: <CAABZP2yE+3vzd+LgJDJcJ2f8qttJQSUQ6efD9MaFd2iD4xPTZA@mail.gmail.com>
On Mon, Jul 19, 2021 at 10:24:18AM +0800, Zhouyi Zhou wrote:
> Meanwhile, I examined the 5.12.17 by naked eye, and found a suspicious place
> that could possibly trigger that problem:
>
> struct swap_info_struct *get_swap_device(swp_entry_t entry)
> {
> struct swap_info_struct *si;
> unsigned long offset;
>
> if (!entry.val)
> goto out;
> si = swp_swap_info(entry);
> if (!si)
> goto bad_nofile;
>
> rcu_read_lock();
> if (data_race(!(si->flags & SWP_VALID)))
> goto unlock_out;
> offset = swp_offset(entry);
> if (offset >= si->max)
> goto unlock_out;
>
> return si;
> bad_nofile:
> pr_err("%s: %s%08lx\n", __func__, Bad_file, entry.val);
> out:
> return NULL;
> unlock_out:
> rcu_read_unlock();
> return NULL;
> }
> I guess the function "return si" without a rcu_read_unlock.
Yes, but the caller is supposed to call put_swap_device() which
calls rcu_read_unlock(). See commit eb085574a752.
next prev parent reply other threads:[~2021-07-19 2:44 UTC|newest]
Thread overview: 34+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <c9fd1311-662c-f993-c8ef-54af036f2f78@googlemail.com>
2021-07-18 21:01 ` linux-5.13.2: warning from kernel/rcu/tree_plugin.h:359 Oleksandr Natalenko
2021-07-18 21:03 ` Oleksandr Natalenko
2021-07-18 21:22 ` Matthew Wilcox
2021-07-18 21:36 ` Chris Clayton
2021-07-18 21:59 ` Paul E. McKenney
2021-07-18 22:51 ` Matthew Wilcox
2021-07-19 1:53 ` Paul E. McKenney
2021-07-19 2:24 ` Zhouyi Zhou
2021-07-19 2:27 ` Zhouyi Zhou
2021-07-19 2:43 ` Matthew Wilcox [this message]
2021-07-19 2:59 ` Zhouyi Zhou
2021-07-19 10:14 ` Boqun Feng
2021-07-19 11:12 ` Miaohe Lin
2021-07-19 11:17 ` Oleksandr Natalenko
2021-07-19 11:22 ` Matthew Wilcox
2021-07-19 11:50 ` Miaohe Lin
2021-07-19 11:59 ` Oleksandr Natalenko
2021-07-19 12:08 ` Miaohe Lin
2021-07-19 12:12 ` Oleksandr Natalenko
2021-07-19 12:16 ` Matthew Wilcox
2021-07-19 12:23 ` Oleksandr Natalenko
2021-07-19 16:47 ` Zhouyi Zhou
[not found] ` <CAABZP2yh3J8+P=3PLZVaC47ymKC7PcfQCBBxjXJ9Ybn+HREbdg@mail.gmail.com>
2021-07-22 7:30 ` Chris Clayton
2021-07-22 8:57 ` Zhouyi Zhou
2021-07-22 12:36 ` Matthew Wilcox
2021-07-22 13:26 ` Greg KH
2021-07-22 14:00 ` Greg KH
2021-07-23 1:51 ` Miaohe Lin
2021-07-23 7:02 ` Greg KH
2021-07-23 7:13 ` Miaohe Lin
2021-07-22 17:44 ` Zhouyi Zhou
2021-07-22 14:05 ` Paul E. McKenney
2021-07-19 12:17 ` Miaohe Lin
2021-07-19 7:32 ` Chris Clayton
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