Hi! IMHO the fix isnt good due to possible race condition which will destroy session/task objects - either by a call to kthread_stop from the timer func or reentry to hidp_del_connection() on smp platforms. see the intopic comments > -----Original Message----- > From: linux-bluetooth-owner@xxxxxxxxxxxxxxx [mailto:linux-bluetooth- > owner@xxxxxxxxxxxxxxx] On Behalf Of Peter Hurley > Sent: Sunday, June 26, 2011 12:33 AM > To: linux-bluetooth > Subject: [PATCH] Bluetooth: Fix hidp disconnect deadlock > > Release reader lock on r/w sem before stopping khidp thread (which > needs to > claim the writer lock on sem before unlinking the session). > > NB: kthread_stop waits for thread completion. > --- > net/bluetooth/hidp/core.c | 5 ++++- > 1 files changed, 4 insertions(+), 1 deletions(-) > > diff --git a/net/bluetooth/hidp/core.c b/net/bluetooth/hidp/core.c > index c405a95..16d75d7 100644 > --- a/net/bluetooth/hidp/core.c > +++ b/net/bluetooth/hidp/core.c > @@ -1096,6 +1096,7 @@ int hidp_del_connection(struct hidp_conndel_req > *req) > { > struct hidp_session *session; > int err = 0; > + bool stop_thread = false; > > BT_DBG(""); > > @@ -1111,12 +1112,14 @@ int hidp_del_connection(struct hidp_conndel_req > *req) > skb_queue_purge(&session->ctrl_transmit); > skb_queue_purge(&session->intr_transmit); > > - kthread_stop(session->task); > + stop_thread = true; > } > } else > err = -ENOENT; > > up_read(&hidp_session_sem); > + if (stop_thread) Timer fires here - session is destroyed. > + kthread_stop(session->task); > return err; > } > > -- > 1.7.4.1 > > -- > To unsubscribe from this list: send the line "unsubscribe linux- > bluetooth" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html I am working on a better solution which will ensure the async deletion of session kthread operates correctly from different exec. contexts Regards Ilia Kolominsky iliak@xxxxxx Direct: +972(9)7906231 Mobile: +972(54)909009 -- To unsubscribe from this list: send the line "unsubscribe linux-bluetooth" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
