[PATCH] mei: fix mismatch in mutex unlock-lock in mei_amthif_read()

From: Alexey Khoroshilov
Date: Fri Dec 21 2012 - 16:44:16 EST


Users of mei_amthif_read() expect it leaves dev->device_lock held,
while there is a path where mei_amthif_read() unlocks device_lock
and returns -ERESTARTSYS.

The patch move code locking device_lock back before the return.

Found by Linux Driver Verification project (linuxtesting.org).

Signed-off-by: Alexey Khoroshilov <khoroshilov@xxxxxxxxx>
---
drivers/misc/mei/amthif.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/misc/mei/amthif.c b/drivers/misc/mei/amthif.c
index 18794ae..e40ffd9 100644
--- a/drivers/misc/mei/amthif.c
+++ b/drivers/misc/mei/amthif.c
@@ -187,13 +187,13 @@ int mei_amthif_read(struct mei_device *dev, struct file *file,
wait_ret = wait_event_interruptible(dev->iamthif_cl.wait,
(cb = mei_amthif_find_read_list_entry(dev, file)));

+ /* Locking again the Mutex */
+ mutex_lock(&dev->device_lock);
+
if (wait_ret)
return -ERESTARTSYS;

dev_dbg(&dev->pdev->dev, "woke up from sleep\n");
-
- /* Locking again the Mutex */
- mutex_lock(&dev->device_lock);
}


--
1.7.9.5

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