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| author | Jiri Slaby <jslaby@suse.cz> | 2015-11-02 10:27:00 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2015-11-19 16:31:42 -0800 |
| commit | 19cd80a214821f4b558560ebd76bfb2c38b4f3d8 (patch) | |
| tree | dc8279ee536572a8f94c6993c61506aaafbac5ef | |
| parent | 44243ef42d77ae367e6e9c68afca3b4578d2d461 (diff) | |
| download | op-kernel-dev-19cd80a214821f4b558560ebd76bfb2c38b4f3d8.zip op-kernel-dev-19cd80a214821f4b558560ebd76bfb2c38b4f3d8.tar.gz | |
usblp: do not set TASK_INTERRUPTIBLE before lock
It is not permitted to set task state before lock. usblp_wwait sets
the state to TASK_INTERRUPTIBLE and calls mutex_lock_interruptible.
Upon return from that function, the state will be TASK_RUNNING again.
This is clearly a bug and a warning is generated with LOCKDEP too:
WARNING: CPU: 1 PID: 5109 at kernel/sched/core.c:7404 __might_sleep+0x7d/0x90()
do not call blocking ops when !TASK_RUNNING; state=1 set at [<ffffffffa0c588d0>] usblp_wwait+0xa0/0x310 [usblp]
Modules linked in: ...
CPU: 1 PID: 5109 Comm: captmon Tainted: G W 4.2.5-0.gef2823b-default #1
Hardware name: LENOVO 23252SG/23252SG, BIOS G2ET33WW (1.13 ) 07/24/2012
ffffffff81a4edce ffff880236ec7ba8 ffffffff81716651 0000000000000000
ffff880236ec7bf8 ffff880236ec7be8 ffffffff8106e146 0000000000000282
ffffffff81a50119 000000000000028b 0000000000000000 ffff8802dab7c508
Call Trace:
...
[<ffffffff8106e1c6>] warn_slowpath_fmt+0x46/0x50
[<ffffffff8109a8bd>] __might_sleep+0x7d/0x90
[<ffffffff8171b20f>] mutex_lock_interruptible_nested+0x2f/0x4b0
[<ffffffffa0c588fc>] usblp_wwait+0xcc/0x310 [usblp]
[<ffffffffa0c58bb2>] usblp_write+0x72/0x350 [usblp]
[<ffffffff8121ed98>] __vfs_write+0x28/0xf0
...
Commit 7f477358e2384c54b190cc3b6ce28277050a041b (usblp: Implement the
ENOSPC convention) moved the set prior locking. So move it back after
the lock.
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Fixes: 7f477358e2 ("usblp: Implement the ENOSPC convention")
Acked-By: Pete Zaitcev <zaitcev@yahoo.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | drivers/usb/class/usblp.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/usb/class/usblp.c b/drivers/usb/class/usblp.c index 433bbc3..071964c 100644 --- a/drivers/usb/class/usblp.c +++ b/drivers/usb/class/usblp.c @@ -884,11 +884,11 @@ static int usblp_wwait(struct usblp *usblp, int nonblock) add_wait_queue(&usblp->wwait, &waita); for (;;) { - set_current_state(TASK_INTERRUPTIBLE); if (mutex_lock_interruptible(&usblp->mut)) { rc = -EINTR; break; } + set_current_state(TASK_INTERRUPTIBLE); rc = usblp_wtest(usblp, nonblock); mutex_unlock(&usblp->mut); if (rc <= 0) |
