From mboxrd@z Thu Jan 1 00:00:00 1970 From: Eric Dumazet Subject: Re: Regression in 3.8-rc1: "BUG: sleeping function called from invalid context" Date: Sat, 22 Dec 2012 10:10:28 -0800 Message-ID: <1356199828.21834.8500.camel@edumazet-glaptop> References: <50D5E9D9.3070904@lwfinger.net> <20121222180247.GA10250@liondog.tnic> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Cc: Larry Finger , LKML , Christoph Lameter , Pekka Enberg , netdev@vger.kernel.org To: Borislav Petkov Return-path: Received: from mail-pa0-f49.google.com ([209.85.220.49]:48442 "EHLO mail-pa0-f49.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751937Ab2LVSKb (ORCPT ); Sat, 22 Dec 2012 13:10:31 -0500 In-Reply-To: <20121222180247.GA10250@liondog.tnic> Sender: netdev-owner@vger.kernel.org List-ID: On Sat, 2012-12-22 at 19:02 +0100, Borislav Petkov wrote: > Top-posting so that the rest can remain untouched. > > Right, so AFAICT, something is holding rtnl_mutex (probably some > rtnetlink traffic) and device_rename() is doing kstrdup with > GFP_KERNEL which, among others, has __GFP_WAIT and *that* triggers the > might_sleep_if() check in slab_pre_alloc_hook(): > > static inline int slab_pre_alloc_hook(struct kmem_cache *s, gfp_t flags) > { > flags &= gfp_allowed_mask; > lockdep_trace_alloc(flags); > might_sleep_if(flags & __GFP_WAIT); <--- HERE > > Adding Christoph and Pekka although the slub.c might_sleep stuff is from > 2010. Still, they might have a better idea. > > Oh well, let's add netdev while we're at it. :-) RTNL is a mutex, its perfectly valid to use GFP_KERNEL while holding a mutex. As replied before your mail, fix for the problem is already in David tree. http://git.kernel.org/?p=linux/kernel/git/davem/net.git;a=commitdiff;h=30e6c9fa93cf3dbc7cc6df1d748ad25e4264545a Bug was added in commit c91f6df2db4972d3cc983e6988b9abf1ad02f5f9 : http://git.kernel.org/?p=linux/kernel/git/davem/net.git;a=commit;h=c91f6df2db4972d3cc983e6988b9abf1ad02f5f9 Thanks