Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751739AbaFEIA3 (ORCPT ); Thu, 5 Jun 2014 04:00:29 -0400 Received: from mga11.intel.com ([192.55.52.93]:59321 "EHLO mga11.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751251AbaFEIA1 (ORCPT ); Thu, 5 Jun 2014 04:00:27 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.97,862,1389772800"; d="scan'208";a="351330422" Message-ID: <53902398.70005@linux.intel.com> Date: Thu, 05 Jun 2014 16:00:24 +0800 From: "Zhang, Yanmin" User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:24.0) Gecko/20100101 Thunderbird/24.5.0 MIME-Version: 1.0 To: Peter Zijlstra , Liu ShuoX CC: linux-kernel@vger.kernel.org, "H. Peter Anvin" , Ingo Molnar , Zhang Yanmin Subject: Re: [PATCH] perf: fix kernel panic when parsing user space CS saved in pt_regs References: <20140605023610.GA12905@lskakaxi-intel> <20140605071919.GD3213@twins.programming.kicks-ass.net> <20140605073321.GA14869@lskakaxi-intel> <20140605075507.GA6758@twins.programming.kicks-ass.net> In-Reply-To: <20140605075507.GA6758@twins.programming.kicks-ass.net> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2014/6/5 15:55, Peter Zijlstra wrote: > On Thu, Jun 05, 2014 at 03:33:21PM +0800, Liu ShuoX wrote: >> On Thu 5.Jun'14 at 9:19:19 +0200, Peter Zijlstra wrote: >>> On Thu, Jun 05, 2014 at 10:36:10AM +0800, Liu ShuoX wrote: >>>> From: Zhang Yanmin >>>> >>>> We hit a kernel panic when running perf to collect some performance data. >>>> kenel is x86_64 and user space apps are 32bit. >>>> >>>> [ 71.965351, 1] [ Binder_2] BUG: unable to handle kernel NULL pointer dereference at 0000000000000004 >>>> [ 71.965360, 1] [ Binder_2] IP: [] get_segment_base+0x71/0xc0 >>>> [ 71.965367, 1] [ Binder_2] PGD 6c65f067 PUD 0 >>>> [ 71.965375, 1] [ Binder_2] Oops: 0000 [#1] PREEMPT SMP >>>> [ 71.965413, 1] [ Binder_2] Modules linked in: ddrgx snd_merr_dpcm_wm8958 snd_intel_sst snd_soc_sst_platform snd_soc_wm8994 snd_soc_wm_hubs lm3559 imx1x5 atomisp_css2401a0_v21 libmsrlisthelper rmi4 bcm_bt_lpm videobuf_vmalloc videobuf_core fps_throttle hdmi_audio pn544(O) tngdisp bcm4335(O) cfg80211 >>>> [ 71.965420, 1] [ Binder_2] CPU: 1 PID: 304 Comm: Binder_2 Tainted: G W O 3.10.20-263902-g184bfbc-dirty #14 >>>> [ 71.965426, 1] [ Binder_2] task: ffff8800764dc300 ti: ffff88006c6e8000 task.ti: ffff88006c6e8000 >>>> [ 71.965439, 1] [ Binder_2] RIP: 0010:[] [] get_segment_base+0x71/0xc0 >>> ^ >>>> [ 71.965<44, 1] [ Binder_2] RSP: 0018:ffff^X8007ea87b98 EFLAGS: 00010092 >>> ^ ^ >>>> [ 71.965447, 1] [ !Binder_2] RAX: 0000000000000024 RBX: 0000000000000000 RCX: 0000000000000000 >>> ^ >>>> [ 71.965450, 1] [ Binder_2] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000009 >>>> [ 71.965454, 1] [ Binder_2] RBP: ffff88007ea87ba8 R08: ffffffff83143b3c R09: ffffffff831848a8 >>>> [ 71.965458, 1] [ Binder_2] R10: 0000000000000000 R11: 00000000001bf2d8 R12: 0000000000000000 >>>> [ 71.965462, 1] [ Binder_2] R13: ffff88006c6e9fd8 R14: ffff88006c6e9f58 R15: ffff8800764dc300 >>>> [ 71.965468, 1_ [ Binder_2] FS: 0000000000000000(0000) GS:ffff88007ea80000(006b) knlGS:00000000f704add0 >>> ^ >>> >>> Are you suffering some serious corruption? >> The log captured by pstore after rebooting, so there are some >> corruption. Please ignore those. > Why does pstore cause corruption? I thought that stuff was supposed to > be 'good' ? pstore is good if the board is reset by WarmReset as memory content is kept across rebooting. If it's a ColdReset, memory might lose some or all contents. My board uses Coldreset, which is a very fast ColdReset. Most memory content can be kept. But sometimes, some data has little change. Yanmin -- 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/