tun: fix blocking read

[ Upstream commit 71828b2240692cec0e68b8d867bc00e1745e7fae ]

This patch moves setting of the current state into the loop. Otherwise
the task may end up in a busy wait loop if none of the break conditions
are met.

Signed-off-by: Timur Celik <mail@timurcelik.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/net/tun.c b/drivers/net/tun.c
index 65844f2..27ac30d 100644 (file)
--- a/drivers/net/tun.c
+++ b/drivers/net/tun.c
@@ -2122,9 +2122,9 @@ static void *tun_ring_recv(struct tun_file *tfile, int noblock, int *err)
        }
 
        add_wait_queue(&tfile->wq.wait, &wait);
-       current->state = TASK_INTERRUPTIBLE;
 
        while (1) {
+               set_current_state(TASK_INTERRUPTIBLE);
                ptr = ptr_ring_consume(&tfile->tx_ring);
                if (ptr)
                        break;
@@ -2140,7 +2140,7 @@ static void *tun_ring_recv(struct tun_file *tfile, int noblock, int *err)
                schedule();
        }
 
-       current->state = TASK_RUNNING;
+       set_current_state(TASK_RUNNING);
        remove_wait_queue(&tfile->wq.wait, &wait);
 
 out: