ptp: Fix some locking bugs in ptp_read()

In ptp_read there is an unlock missing on an error path, and a double
unlock on another error path.

Signed-off-by: Dan Carpenter <error27@gmail.com>
Acked-by: Richard Cochran <richard.cochran@omicron.at>
Signed-off-by: John Stultz <john.stultz@linaro.org>

1 files changed, 4 insertions, 4 deletions

diff --git a/drivers/ptp/ptp_chardev.c b/drivers/ptp/ptp_chardev.c
index 93fa22de5977..e7f301da2902 100644
--- a/drivers/ptp/ptp_chardev.c
+++ b/drivers/ptp/ptp_chardev.c
@@ -130,8 +130,10 @@ ssize_t ptp_read(struct posix_clock *pc,
                 return -ERESTARTSYS;
         }
 
-        if (ptp->defunct)
+        if (ptp->defunct) {
+                mutex_unlock(&ptp->tsevq_mux);
                 return -ENODEV;
+        }
 
         spin_lock_irqsave(&queue->lock, flags);
 
@@ -151,10 +153,8 @@ ssize_t ptp_read(struct posix_clock *pc,
 
         mutex_unlock(&ptp->tsevq_mux);
 
-        if (copy_to_user(buf, event, cnt)) {
-                mutex_unlock(&ptp->tsevq_mux);
+        if (copy_to_user(buf, event, cnt))
                 return -EFAULT;
-        }
 
         return cnt;
 }