Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755869Ab3I3RMN (ORCPT ); Mon, 30 Sep 2013 13:12:13 -0400 Received: from mx1.redhat.com ([209.132.183.28]:3730 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755812Ab3I3RMK (ORCPT ); Mon, 30 Sep 2013 13:12:10 -0400 Date: Mon, 30 Sep 2013 13:12:01 -0400 From: Dave Jones To: Steven Rostedt Cc: Linux Kernel Subject: Re: FTRACE_WARN_ON((rec->flags & ~FTRACE_FL_MASK) == 0)) Message-ID: <20130930171201.GA10474@redhat.com> Mail-Followup-To: Dave Jones , Steven Rostedt , Linux Kernel References: <20130828034627.GA30596@redhat.com> <20130828095408.37c3dd83@gandalf.local.home> <20130828095833.103ccdf0@gandalf.local.home> <20130828111746.35369b84@gandalf.local.home> <20130828182710.GA14103@redhat.com> <20130828182902.GB14103@redhat.com> <20130828152745.18a73c4e@gandalf.local.home> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20130828152745.18a73c4e@gandalf.local.home> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3054 Lines: 46 On Wed, Aug 28, 2013 at 03:27:45PM -0400, Steven Rostedt wrote: > > [ 6619.050768] WARNING: CPU: 1 PID: 16351 at kernel/trace/ftrace.c:1640 __ftrace_hash_rec_update.part.37+0x20a/0x240() > > [ 6619.053767] Modules linked in: lec snd_seq_dummy bridge stp fuse tun bnep hidp rfcomm nfnetlink ipt_ULOG scsi_transport_iscsi can_bcm can_raw nfc caif_socket caif af_802154 phonet af_rxrpc bluetooth rfkill can llc2 pppoe pppox ppp_generic slhc irda crc_ccitt rds af_key rose x25 atm netrom appletalk ipx p8023 psnap p8022 llc ax25 xfs libcrc32c snd_hda_codec_realtek snd_hda_intel snd_hda_codec snd_hwdep snd_seq snd_seq_device snd_pcm snd_page_alloc e1000e ptp snd_timer pcspkr pps_core snd soundcore usb_debug > > [ 6619.060523] CPU: 1 PID: 16351 Comm: trinity-child2 Not tainted 3.11.0-rc7+ #31 > > [ 6619.062161] ffffffff81a21901 ffff8802267b9ce0 ffffffff816f9e4f 0000000000000000 > > [ 6619.063733] ffff8802267b9d18 ffffffff81052dcd 0000000000000000 0000000000000001 > > [ 6619.065309] ffff8802203a3000 0000000000000000 ffff880225e962d0 ffff8802267b9d28 > > [ 6619.066895] Call Trace: > > [ 6619.068437] [] dump_stack+0x54/0x74 > > [ 6619.070046] [] warn_slowpath_common+0x7d/0xa0 > > [ 6619.071642] [] warn_slowpath_null+0x1a/0x20 > > [ 6619.073224] [] __ftrace_hash_rec_update.part.37+0x20a/0x240 > > [ 6619.074817] [] ftrace_shutdown+0xb8/0x160 > > [ 6619.076399] [] unregister_ftrace_function+0x30/0x50 > > [ 6619.077983] [] perf_ftrace_event_register+0x87/0x150 > > [ 6619.079565] [] perf_trace_destroy+0x2c/0x50 > > [ 6619.081180] [] tp_perf_event_destroy+0x9/0x10 > > [ 6619.082742] [] free_event+0xa7/0x300 > > [ 6619.084264] [] __perf_event_exit_task+0xe0/0x130 > > [ 6619.085792] [] perf_event_exit_task+0x1f1/0x230 > > [ 6619.087329] [] do_exit+0x30d/0xcd0 > > [ 6619.088860] [] ? ftrace_call+0x5/0x2f > > [ 6619.090460] [] do_group_exit+0x4c/0xc0 > > [ 6619.092036] [] SyS_exit_group+0x14/0x20 > > [ 6619.093614] [] tracesys+0xdd/0xe2 > > The first failure disables function tracing completely, which is one of > the causes to return an error, which triggered the warning I added. > > I was hoping that it failed for another reason and then that would > cause things to break. But you said the hash corruption happened first > (the original bug), so that's not the case. > > Back to staring at code. Steve, any further thoughts on this ? I can't do more than a few hours of fuzz-testing without eventually running into this. Dave -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/