From 71828b2240692cec0e68b8d867bc00e1745e7fae Mon Sep 17 00:00:00 2001 From: Timur Celik Date: Sat, 23 Feb 2019 12:53:13 +0100 Subject: tun: fix blocking read 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 Signed-off-by: David S. Miller --- drivers/net/tun.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'drivers/net/tun.c') diff --git a/drivers/net/tun.c b/drivers/net/tun.c index fed298c0cb39..d291762b9e9d 100644 --- a/drivers/net/tun.c +++ b/drivers/net/tun.c @@ -2167,9 +2167,9 @@ 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; @@ -2185,7 +2185,7 @@ 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: -- cgit v1.2.3 From ecef67cb10db7b83b3b71c61dbb29aa070ab0112 Mon Sep 17 00:00:00 2001 From: Timur Celik Date: Mon, 25 Feb 2019 21:13:13 +0100 Subject: tun: remove unnecessary memory barrier Replace set_current_state with __set_current_state since no memory barrier is needed at this point. Signed-off-by: Timur Celik Reviewed-by: Eric Dumazet Signed-off-by: David S. Miller --- drivers/net/tun.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'drivers/net/tun.c') diff --git a/drivers/net/tun.c b/drivers/net/tun.c index d291762b9e9d..53f4f37b0ffd 100644 --- a/drivers/net/tun.c +++ b/drivers/net/tun.c @@ -2185,7 +2185,7 @@ static void *tun_ring_recv(struct tun_file *tfile, int noblock, int *err) schedule(); } - set_current_state(TASK_RUNNING); + __set_current_state(TASK_RUNNING); remove_wait_queue(&tfile->wq.wait, &wait); out: -- cgit v1.2.3