]> git.baikalelectronics.ru Git - kernel.git/commit
f2fs: fix potential hangtask in f2fs_trace_pid
authorChao Yu <yuchao0@huawei.com>
Tue, 12 Dec 2017 06:11:40 +0000 (14:11 +0800)
committerJaegeuk Kim <jaegeuk@kernel.org>
Wed, 3 Jan 2018 03:27:30 +0000 (19:27 -0800)
commitb3b4ca147e33a529fed476b8c83eb696d9c52edc
treefc75b374e32ec3a3f9df1a9c675fedd1a42c784d
parent6e50e56b5ffa86926c5360f825c1e04ee27ca2d9
f2fs: fix potential hangtask in f2fs_trace_pid

As Jia-Ju Bai reported:

"According to fs/f2fs/trace.c, the kernel module may sleep under a spinlock.
The function call path is:
f2fs_trace_pid (acquire the spinlock)
   f2fs_radix_tree_insert
     cond_resched --> may sleep

I do not find a good way to fix it, so I only report.
This possible bug is found by my static analysis tool (DSAC) and my code
review."

Obviously, it's problemetic to schedule in critical region of spinlock,
which will cause uninterruptable sleep if there is no waker.

This patch changes to use mutex lock intead of spinlock to avoid this
condition.

Reported-by: Jia-Ju Bai <baijiaju1990@gmail.com>
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
fs/f2fs/trace.c