printk: Fix rq->lock vs logbuf_lock unlock lock inversion
authorBu, Yitian <ybu@qti.qualcomm.com>
Mon, 18 Feb 2013 12:53:37 +0000 (12:53 +0000)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Mon, 14 Apr 2014 13:44:16 +0000 (06:44 -0700)
commitaa34e62c2f0d4a105606971a1eb666f22338993b
tree0dff0ab9129f77e0e510a1c82c29027751959313
parent0df19efa7549d47aa906b8316665e46366b56061
printk: Fix rq->lock vs logbuf_lock unlock lock inversion

commit dbda92d16f8655044e082930e4e9d244b87fde77 upstream.

commit 07354eb1a74d1 ("locking printk: Annotate logbuf_lock as raw")
reintroduced a lock inversion problem which was fixed in commit
0b5e1c5255 ("printk: Release console_sem after logbuf_lock"). This
happened probably when fixing up patch rejects.

Restore the ordering and unlock logbuf_lock before releasing
console_sem.

Signed-off-by: ybu <ybu@qti.qualcomm.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/E807E903FE6CBE4D95E420FBFCC273B827413C@nasanexd01h.na.qualcomm.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Cc: Qiang Huang <h.huangqiang@huawei.com>
Cc: Li Zefan <lizefan@huawei.com>
Cc: Jianguo Wu <wujianguo@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
kernel/printk.c