From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-3.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 47CABC433DB for ; Wed, 24 Mar 2021 11:23:57 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0538D61994 for ; Wed, 24 Mar 2021 11:23:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234581AbhCXLX0 (ORCPT ); Wed, 24 Mar 2021 07:23:26 -0400 Received: from mga14.intel.com ([192.55.52.115]:15020 "EHLO mga14.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231811AbhCXLXE (ORCPT ); Wed, 24 Mar 2021 07:23:04 -0400 IronPort-SDR: 4sPfXJozztFMmGJfwwPLcHN6sKWBNnTMxWCsUdV3LRD0kao4jLqI7CtP+Bnhukw1JwohyEBFm7 Qbr/xhC3dXfA== X-IronPort-AV: E=McAfee;i="6000,8403,9932"; a="190094688" X-IronPort-AV: E=Sophos;i="5.81,274,1610438400"; d="scan'208";a="190094688" Received: from orsmga005.jf.intel.com ([10.7.209.41]) by fmsmga103.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 24 Mar 2021 04:23:04 -0700 IronPort-SDR: MfwqPanb0Iqc+iEtOQA8LkpLg1kxRPa4SNLLV8oYa35Vku0bst3vAN5AzUVeig8hOQFCgusefC tJPJ+dCnMe/g== X-IronPort-AV: E=Sophos;i="5.81,274,1610438400"; d="scan'208";a="593346812" Received: from smile.fi.intel.com (HELO smile) ([10.237.68.40]) by orsmga005-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 24 Mar 2021 04:23:01 -0700 Received: from andy by smile with local (Exim 4.94) (envelope-from ) id 1lP1bG-00FeXS-5N; Wed, 24 Mar 2021 13:22:58 +0200 Date: Wed, 24 Mar 2021 13:22:58 +0200 From: Andy Shevchenko To: Stephen Boyd Cc: Andrew Morton , linux-kernel@vger.kernel.org, Jiri Olsa , Alexei Starovoitov , Jessica Yu , Evan Green , Hsin-Yi Wang , Petr Mladek , Steven Rostedt , Matthew Wilcox Subject: Re: [PATCH v2 03/12] dump_stack: Add vmlinux build ID to stack traces Message-ID: References: <20210324020443.1815557-1-swboyd@chromium.org> <20210324020443.1815557-4-swboyd@chromium.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210324020443.1815557-4-swboyd@chromium.org> Organization: Intel Finland Oy - BIC 0357606-4 - Westendinkatu 7, 02160 Espoo Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Mar 23, 2021 at 07:04:34PM -0700, Stephen Boyd wrote: > Add the running kernel's build ID[1] to the stacktrace information > header. This makes it simpler for developers to locate the vmlinux with > full debuginfo for a particular kernel stacktrace. Combined with > scripts/decode_stracktrace.sh, a developer can download the correct > vmlinux from a debuginfod[2] server and find the exact file and line > number for the functions plus offsets in a stacktrace. > > This is especially useful for pstore crash debugging where the kernel > crashes are recorded in the pstore logs and the recovery kernel is > different or the debuginfo doesn't exist on the device due to space > concerns (the data can be large and a security concern). The stacktrace > can be analyzed after the crash by using the build ID to find the > matching vmlinux and understand where in the function something went > wrong. > > Example stacktrace from lkdtm: Can we drop the noise from the example and leave only important part(s)? > WARNING: CPU: 4 PID: 3255 at drivers/misc/lkdtm/bugs.c:83 lkdtm_WARNING+0x28/0x30 [lkdtm] > Modules linked in: lkdtm rfcomm algif_hash algif_skcipher af_alg xt_cgroup uinput xt_MASQUERADE > CPU: 4 PID: 3255 Comm: bash Not tainted 5.11 #3 aa23f7a1231c229de205662d5a9e0d4c580f19a1 > Hardware name: Google Lazor (rev3+) with KB Backlight (DT) > pstate: 00400009 (nzcv daif +PAN -UAO -TCO BTYPE=--) > pc : lkdtm_WARNING+0x28/0x30 [lkdtm] > lr : lkdtm_do_action+0x24/0x40 [lkdtm] > sp : ffffffc0134fbca0 > x29: ffffffc0134fbca0 x28: ffffff92d53ba240 > x27: 0000000000000000 x26: 0000000000000000 > x25: 0000000000000000 x24: ffffffe3622352c0 > x23: 0000000000000020 x22: ffffffe362233366 > x21: ffffffe3622352e0 x20: ffffffc0134fbde0 > x19: 0000000000000008 x18: 0000000000000000 > x17: ffffff929b6536fc x16: 0000000000000000 > x15: 0000000000000000 x14: 0000000000000012 > x13: ffffffe380ed892c x12: ffffffe381d05068 > x11: 0000000000000000 x10: 0000000000000000 > x9 : 0000000000000001 x8 : ffffffe362237000 > x7 : aaaaaaaaaaaaaaaa x6 : 0000000000000000 > x5 : 0000000000000000 x4 : 0000000000000001 > x3 : 0000000000000008 x2 : ffffff93fef25a70 > x1 : ffffff93fef15788 x0 : ffffffe3622352e0 > Call trace: > lkdtm_WARNING+0x28/0x30 [lkdtm] > direct_entry+0x16c/0x1b4 [lkdtm] > full_proxy_write+0x74/0xa4 > vfs_write+0xec/0x2e8 > ksys_write+0x84/0xf0 > __arm64_sys_write+0x24/0x30 > el0_svc_common+0xf4/0x1c0 > do_el0_svc_compat+0x28/0x3c > el0_svc_compat+0x10/0x1c > el0_sync_compat_handler+0xa8/0xcc > el0_sync_compat+0x178/0x180 > ---[ end trace 3d95032303e59e68 ]--- > > The hex string aa23f7a1231c229de205662d5a9e0d4c580f19a1 is the build ID, > following the kernel version number. -- With Best Regards, Andy Shevchenko