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authorMichael Scott <michael.scott@linaro.org>2017-03-28 23:10:54 -0700
committerMarcel Holtmann <marcel@holtmann.org>2017-04-12 22:02:39 +0200
commitd2891c4d071d807f01cc911dc42a68f4568d65cf (patch)
tree11fe32602ffc595edfca746689440d392e2b42f2 /net/bluetooth
parentdcb9cfaa5ea9aa0ec08aeb92582ccfe3e4c719a9 (diff)
Bluetooth: 6lowpan: fix delay work init in add_peer_chan()
When adding 6lowpan devices very rapidly we sometimes see a crash: [23122.306615] CPU: 2 PID: 0 Comm: swapper/2 Not tainted 4.9.0-43-arm64 #1 Debian 4.9.9.linaro.43-1 [23122.315400] Hardware name: HiKey Development Board (DT) [23122.320623] task: ffff800075443080 task.stack: ffff800075484000 [23122.326551] PC is at expire_timers+0x70/0x150 [23122.330907] LR is at run_timer_softirq+0xa0/0x1a0 [23122.335616] pc : [<ffff000008142dd8>] lr : [<ffff000008142f58>] pstate: 600001c5 This was due to add_peer_chan() unconditionally initializing the lowpan_btle_dev->notify_peers delayed work structure, even if the lowpan_btle_dev passed into add_peer_chan() had previously been initialized. Normally, this would go unnoticed as the delayed work timer is set for 100 msec, however when calling add_peer_chan() faster than 100 msec it clears out a previously queued delay work causing the crash above. To fix this, let add_peer_chan() know when a new lowpan_btle_dev is passed in so that it only performs the delay work initialization when needed. Signed-off-by: Michael Scott <michael.scott@linaro.org> Acked-by: Jukka Rissanen <jukka.rissanen@linux.intel.com> Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Diffstat (limited to 'net/bluetooth')
-rw-r--r--net/bluetooth/6lowpan.c10
1 files changed, 7 insertions, 3 deletions
diff --git a/net/bluetooth/6lowpan.c b/net/bluetooth/6lowpan.c
index ba28c7b1557f..6ae51e840af1 100644
--- a/net/bluetooth/6lowpan.c
+++ b/net/bluetooth/6lowpan.c
@@ -676,7 +676,8 @@ static struct l2cap_chan *chan_create(void)
}
static struct l2cap_chan *add_peer_chan(struct l2cap_chan *chan,
- struct lowpan_btle_dev *dev)
+ struct lowpan_btle_dev *dev,
+ bool new_netdev)
{
struct lowpan_peer *peer;
@@ -697,7 +698,8 @@ static struct l2cap_chan *add_peer_chan(struct l2cap_chan *chan,
spin_unlock(&devices_lock);
/* Notifying peers about us needs to be done without locks held */
- INIT_DELAYED_WORK(&dev->notify_peers, do_notify_peers);
+ if (new_netdev)
+ INIT_DELAYED_WORK(&dev->notify_peers, do_notify_peers);
schedule_delayed_work(&dev->notify_peers, msecs_to_jiffies(100));
return peer->chan;
@@ -755,6 +757,7 @@ out:
static inline void chan_ready_cb(struct l2cap_chan *chan)
{
struct lowpan_btle_dev *dev;
+ bool new_netdev = false;
dev = lookup_dev(chan->conn);
@@ -765,12 +768,13 @@ static inline void chan_ready_cb(struct l2cap_chan *chan)
l2cap_chan_del(chan, -ENOENT);
return;
}
+ new_netdev = true;
}
if (!try_module_get(THIS_MODULE))
return;
- add_peer_chan(chan, dev);
+ add_peer_chan(chan, dev, new_netdev);
ifup(dev->netdev);
}