| From | Greg Kroah-Hartman <> | Subject | [PATCH 4.9 66/84] Bluetooth: bnep: fix possible might sleep error in bnep_session | Date | Mon, 28 Aug 2017 10:05:31 +0200 |
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4.9-stable review patch. If anyone has any objections, please let me know.
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From: Jeffy Chen <jeffy.chen@rock-chips.com>
commit 25717382c1dd0ddced2059053e3ca5088665f7a5 upstream.
It looks like bnep_session has same pattern as the issue reported in old rfcomm:
while (1) { set_current_state(TASK_INTERRUPTIBLE); if (condition) break; // may call might_sleep here schedule(); } __set_current_state(TASK_RUNNING);
Which fixed at: dfb2fae Bluetooth: Fix nested sleeps
So let's fix it at the same way, also follow the suggestion of: https://lwn.net/Articles/628628/
Signed-off-by: Jeffy Chen <jeffy.chen@rock-chips.com> Reviewed-by: Brian Norris <briannorris@chromium.org> Reviewed-by: AL Yu-Chen Cho <acho@suse.com> Signed-off-by: Marcel Holtmann <marcel@holtmann.org> Cc: Jiri Slaby <jslaby@suse.cz> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
--- net/bluetooth/bnep/core.c | 11 +++++------ 1 file changed, 5 insertions(+), 6 deletions(-)
--- a/net/bluetooth/bnep/core.c +++ b/net/bluetooth/bnep/core.c @@ -484,16 +484,16 @@ static int bnep_session(void *arg) struct net_device *dev = s->dev; struct sock *sk = s->sock->sk; struct sk_buff *skb; - wait_queue_t wait; + DEFINE_WAIT_FUNC(wait, woken_wake_function); BT_DBG(""); set_user_nice(current, -15); - init_waitqueue_entry(&wait, current); add_wait_queue(sk_sleep(sk), &wait); while (1) { - set_current_state(TASK_INTERRUPTIBLE); + /* Ensure session->terminate is updated */ + smp_mb__before_atomic(); if (atomic_read(&s->terminate)) break; @@ -515,9 +515,8 @@ static int bnep_session(void *arg) break; netif_wake_queue(dev); - schedule(); + wait_woken(&wait, TASK_INTERRUPTIBLE, MAX_SCHEDULE_TIMEOUT); } - __set_current_state(TASK_RUNNING); remove_wait_queue(sk_sleep(sk), &wait); /* Cleanup session */ @@ -666,7 +665,7 @@ int bnep_del_connection(struct bnep_conn s = __bnep_get_session(req->dst); if (s) { atomic_inc(&s->terminate); - wake_up_process(s->task); + wake_up_interruptible(sk_sleep(s->sock->sk)); } else err = -ENOENT;
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