From: Jia-Ju Bai <baijiaju1990@gmail.com>
To: axboe@kernel.dk, akpm@linux-foundation.or, jack@suse.cz,
zhangweiping@didichuxing.com, sergey.senozhatsky@gmail.com,
andriy.shevchenko@linux.intel.com, christophe.jaillet@wanadoo.fr,
aryabinin@virtuozzo.com
Cc: linux-mm@kvack.org,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: [BUG] mm: backing-dev: a possible sleep-in-atomic-context bug in cgwb_create()
Date: Thu, 21 Jun 2018 11:02:58 +0800 [thread overview]
Message-ID: <626acba3-c565-7e05-6c8b-0d100ff645c5@gmail.com> (raw)
The kernel may sleep with holding a spinlock.
The function call path (from bottom to top) in Linux-4.16.7 is:
[FUNC] schedule
lib/percpu-refcount.c, 222:
schedule in __percpu_ref_switch_mode
lib/percpu-refcount.c, 339:
__percpu_ref_switch_mode in percpu_ref_kill_and_confirm
./include/linux/percpu-refcount.h, 127:
percpu_ref_kill_and_confirm in percpu_ref_kill
mm/backing-dev.c, 545:
percpu_ref_kill in cgwb_kill
mm/backing-dev.c, 576:
cgwb_kill in cgwb_create
mm/backing-dev.c, 573:
_raw_spin_lock_irqsave in cgwb_create
This bug is found by my static analysis tool (DSAC-2) and checked by my
code review.
I do not know how to correctly fix this bug, so I just report them.
Maybe cgwb_kill() should not be called with holding a spinlock.
Best wishes,
Jia-Ju Bai
next reply other threads:[~2018-06-21 3:03 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-06-21 3:02 Jia-Ju Bai [this message]
2018-06-21 3:35 ` Matthew Wilcox
2018-06-22 8:50 ` Jan Kara
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