Commit 751c10a5 authored by Peter Hurley's avatar Peter Hurley Committed by Gustavo F. Padovan

Bluetooth: bnep: Fix deadlock in session deletion

Commit f4d7cd4a introduced the usage of kthread API.
kthread_stop is a blocking function which returns only when
the thread exits. In this case, the thread can't exit because it's
waiting for the write lock, which is being held by bnep_del_connection()
which is waiting for the thread to exit -- deadlock.

Use atomic_t/wake_up_process instead to signal to the thread to exit.
Signed-off-by: default avatarJaikumar Ganesh <jaikumar@google.com>
Signed-off-by: default avatarPeter Hurley <peter@hurleysoftware.com>
Signed-off-by: default avatarGustavo F. Padovan <padovan@profusion.mobi>
parent 7bdb8a5c
......@@ -155,6 +155,7 @@ struct bnep_session {
unsigned int role;
unsigned long state;
unsigned long flags;
atomic_t terminate;
struct task_struct *task;
struct ethhdr eh;
......
......@@ -487,7 +487,7 @@ static int bnep_session(void *arg)
while (1) {
set_current_state(TASK_INTERRUPTIBLE);
if (kthread_should_stop())
if (atomic_read(&s->terminate))
break;
/* RX */
while ((skb = skb_dequeue(&sk->sk_receive_queue))) {
......@@ -642,9 +642,10 @@ int bnep_del_connection(struct bnep_conndel_req *req)
down_read(&bnep_session_sem);
s = __bnep_get_session(req->dst);
if (s)
kthread_stop(s->task);
else
if (s) {
atomic_inc(&s->terminate);
wake_up_process(s->task);
} else
err = -ENOENT;
up_read(&bnep_session_sem);
......
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