Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755194AbZGYHx5 (ORCPT ); Sat, 25 Jul 2009 03:53:57 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752749AbZGYHx4 (ORCPT ); Sat, 25 Jul 2009 03:53:56 -0400 Received: from smtp1.linux-foundation.org ([140.211.169.13]:34201 "EHLO smtp1.linux-foundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751612AbZGYHxz (ORCPT ); Sat, 25 Jul 2009 03:53:55 -0400 Date: Sat, 25 Jul 2009 00:53:50 -0700 From: Andrew Morton To: Christophe Lermytte Cc: linux-kernel@vger.kernel.org, cpufreq@vger.kernel.org Subject: Re: 2.6.31-rc3 cpufreq bug (null pointer dereference) Message-Id: <20090725005350.bb4db4ad.akpm@linux-foundation.org> In-Reply-To: <1248206869.4516.6.camel@localhost> References: <1248206869.4516.6.camel@localhost> X-Mailer: Sylpheed 2.4.8 (GTK+ 2.12.5; x86_64-redhat-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3317 Lines: 69 (cc cpufreq@vger.kernel.org) On Tue, 21 Jul 2009 22:07:49 +0200 Christophe Lermytte wrote: > Today, I tried to change the governor to conservative using the GNOME > cpufreqd applet. The applet subsequently hangs and the following appears > in the kernel traces: > > [ 3067.249054] BUG: unable to handle kernel NULL pointer dereference at > 00000020 > [ 3067.249062] IP: [] dbs_cpufreq_notifier+0x17/0x2b > [ 3067.249074] *pde = 00000000 > [ 3067.249078] Oops: 0000 [#1] SMP > [ 3067.249083] last sysfs > file: /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor > [ 3067.249087] Modules linked in: cdc_wdm cdc_acm > [ 3067.249093] > [ 3067.249098] Pid: 1346, comm: kondemand/1 Not tainted (2.6.31-rc3 #2) > Latitude D630 > [ 3067.249103] EIP: 0060:[] EFLAGS: 00010286 CPU: 1 > [ 3067.249108] EIP is at dbs_cpufreq_notifier+0x17/0x2b > [ 3067.249112] EAX: 00000000 EBX: f6959f00 ECX: 00000000 EDX: c278c300 > [ 3067.249116] ESI: fffffffe EDI: 00000000 EBP: 00000000 ESP: f6959e78 > [ 3067.249120] DS: 007b ES: 007b FS: 00d8 GS: 0000 SS: 0068 > [ 3067.249124] Process kondemand/1 (pid: 1346, ti=f6958000 task=f69020a0 > task.ti=f6958000) > [ 3067.249128] Stack: > [ 3067.249130] c161ba54 c1427067 f6959f00 00000000 c176d000 f6959f00 > c176cfe4 00000000 > [ 3067.249139] <0> c103a57e ffffffff 00000000 00000000 00000001 f64de590 > f8416980 f6959f00 > [ 3067.249149] <0> c103a59c ffffffff 00000000 c100f8b0 f6bcf240 ffffffea > 00000003 00000000 > [ 3067.249160] Call Trace: > [ 3067.249166] [] ? notifier_call_chain+0x2a/0x47 > [ 3067.249175] [] ? __srcu_notifier_call_chain+0x32/0x47 > [ 3067.249181] [] ? srcu_notifier_call_chain+0x9/0xc > [ 3067.249193] [] ? acpi_cpufreq_target+0x1a7/0x2b1 > [ 3067.249197] [] ? get_measured_perf+0x1f/0x140 > [ 3067.249201] [] ? getnstimeofday+0x4d/0xd0 > [ 3067.249205] [] ? cpufreq_register_driver+0xb1/0x15b > [ 3067.249209] [] ? acpi_cpufreq_target+0x0/0x2b1 > [ 3067.249213] [] ? __cpufreq_driver_target+0x49/0x55 > [ 3067.249217] [] ? do_dbs_timer+0x262/0x2b8 > [ 3067.249222] [] ? worker_thread+0x137/0x1b3 > [ 3067.249226] [] ? do_dbs_timer+0x0/0x2b8 > [ 3067.249229] [] ? autoremove_wake_function+0x0/0x2d > [ 3067.249233] [] ? worker_thread+0x0/0x1b3 > [ 3067.249236] [] ? kthread+0x69/0x6e > [ 3067.249240] [] ? kthread+0x0/0x6e > [ 3067.249244] [] ? kernel_thread_helper+0x7/0x10 > [ 3067.249246] Code: c7 44 24 18 ea ff ff ff 8b 44 24 18 83 c4 20 5b 5e > 5f 5d c3 53 8b 01 ba 00 83 6c c1 89 cb 03 14 85 6c b9 66 c1 8b 4a 18 8b > 42 60 <3b> 41 20 77 05 3b 41 1c 73 06 8b 43 08 89 42 60 31 c0 5b c3 53 > [ 3067.249282] EIP: [] dbs_cpufreq_notifier+0x17/0x2b SS:ESP > 0068:f6959e78 > [ 3067.249287] CR2: 0000000000000020 > [ 3067.249296] ---[ end trace 5cb870966b6883a7 ]--- > I assume that this is repeatable and that 2.6.30 was OK? Thanks. -- 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/