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authorJiri Slaby <jslaby@suse.cz>2015-11-02 10:27:00 +0100
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2015-12-09 13:42:59 -0500
commit043c43faae5df411dffe03f79e54d69ddf4eeb3d (patch)
treec118a4e52a7b613b3336da990bc3de7fbd99c927
parent579fdc2ec7e246106142e6504102e2657b7540e4 (diff)
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usblp: do not set TASK_INTERRUPTIBLE before lock
commit 19cd80a214821f4b558560ebd76bfb2c38b4f3d8 upstream. 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> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--drivers/usb/class/usblp.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/usb/class/usblp.c b/drivers/usb/class/usblp.c
index 0924ee40a966..b9adc2ec49dd 100644
--- a/drivers/usb/class/usblp.c
+++ b/drivers/usb/class/usblp.c
@@ -869,11 +869,11 @@ 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)