Return-Path: Date: Tue, 24 Apr 2007 09:59:38 +0200 (CEST) From: Jiri Kosina To: Herbert Xu cc: jeremy@goop.org, Greg KH , Marcel Holtmann , maxk@qualcomm.com, bluez-devel@lists.sourceforge.net, clg@fr.ibm.com, linux-kernel@vger.kernel.org, netdev@vger.kernel.org Subject: Re: 2.6.21-rc7: BUG: sleeping function called from invalid context at net/core/sock.c:1523 In-Reply-To: Message-ID: References: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII List-ID: On Tue, 24 Apr 2007, Herbert Xu wrote: > > Hmm, *sigh*. I guess the patch below fixes the problem, but it is a > > masterpiece in the field of ugliness. And I am not sure whether it is > > completely correct either. Are there any immediate ideas for better > > solution with respect to how struct sock locking works? > Please cc such patches to netdev. Thanks. Hi Herbert, well it's pretty much bluetooth-specific, and bluez-devel was CCed, but OK. > > diff --git a/net/bluetooth/hci_sock.c b/net/bluetooth/hci_sock.c > > index 71f5cfb..c5c93cd 100644 > > --- a/net/bluetooth/hci_sock.c > > +++ b/net/bluetooth/hci_sock.c > > @@ -656,7 +656,10 @@ static int hci_sock_dev_event(struct notifier_block *this, unsigned long event, > > /* Detach sockets from device */ > > read_lock(&hci_sk_list.lock); > > sk_for_each(sk, node, &hci_sk_list.head) { > > - lock_sock(sk); > > + if (in_atomic()) > > + bh_lock_sock(sk); > > + else > > + lock_sock(sk); > > This doesn't do what you think it does. bh_lock_sock can still succeed > even with lock_sock held by someone else. I know, this was precisely the reason why I converted the bh_lock_sock() to lock_sock() here some time ago (as it was racy with l2cap_connect_cfm()). > Does this need to occur immediately when an event occurs? If not I'd > suggest moving this into a workqueue. Will have to check whether this will be processed properly in time when going to suspend. Thanks, -- Jiri Kosina