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=-4.3 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,HK_RANDOM_FROM,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,USER_AGENT_SANE_2 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 C6703C433E0 for ; Mon, 3 Aug 2020 02:53:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A3208206E6 for ; Mon, 3 Aug 2020 02:53:50 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=vfemail.net header.i=@vfemail.net header.b="pMTkGRI4" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726887AbgHCCxu (ORCPT ); Sun, 2 Aug 2020 22:53:50 -0400 Received: from nl101-3.vfemail.net ([149.210.219.33]:20313 "EHLO nl101-3.vfemail.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725820AbgHCCxu (ORCPT ); Sun, 2 Aug 2020 22:53:50 -0400 X-Greylist: delayed 400 seconds by postgrey-1.27 at vger.kernel.org; Sun, 02 Aug 2020 22:53:49 EDT DKIM-Signature: v=1; a=rsa-sha256; c=simple; d=vfemail.net; h=date:from :to:cc:subject:message-id:mime-version:content-type :content-transfer-encoding; s=2018; bh=08R9KsxFKpKXX1ubkuITdn0Va XztBOhySsMuSKH/UO4=; b=pMTkGRI4rTnt5KFjq6poid+bZHQzJJvnIwFTuIccs TdkfI/E2GGTc4mZZFvp1qZlize3YrmZ3XsT2w2Q3oXrX45ug7SRndCNfxuRI/T/W l6T+j1KG+ZVBx87GloDew4nPSYE1uKMqdq2IhfDz8vPvUzSDwXL7XcU0RTudBzsn lc= Received: (qmail 82500 invoked from network); 3 Aug 2020 02:47:09 -0000 Received: by simscan 1.4.0 ppid: 82491, pid: 82498, t: 0.2482s scanners:none Received: from unknown (HELO d3d3MTkyLnZmZW1haWwubmV0) (aGdudGt3aXNAdmZlbWFpbC5uZXQ=@MTkyLjE2OC4xLjE5Mg==) by nl101.vfemail.net with ESMTPA; 3 Aug 2020 02:47:09 -0000 Date: Sun, 2 Aug 2020 22:46:52 -0400 From: David Niklas To: linux-doc@vger.kernel.org Cc: corbet@lwn.net Subject: Re: PROBLEM: Missing debug instructions when EIP is not present Message-ID: <20200802224652.6be413fe@Phenom-II-x6.niklas.com> X-Mailer: Claws Mail 3.17.1 (GTK+ 2.24.31; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-doc-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-doc@vger.kernel.org Hello, I tried categorizing under documentation, but there's only man-pages as the component and my bug was closed as invalid. I've updated the bugzilla link. The file: Documentation/admin-guide/bug-hunting.rst gives instructions on how to find the offending line of code using EIP. My particular bug that I need to report doesn't have EIP listed -- at least not by name. I tried to guess what EIP was in my case "__schedule+0x29e/0x6c0" but that didn't produce any results in gdb on my debug kernel. I don't appear to have the referenced module type problem: "[] :jbd:log_wait_commit+0xa3/0xf5" I'm totally new to kernel debugging so the documentation is really important and I'm rather frustrated in even bothering to read it as it's incomplete/unhelpful. Here's the exact bug I'm trying to tackle. [68812.480447] INFO: task CacheThread_Blo:9414 blocked for more than 480 seconds. [68812.480459] Not tainted 4.14.184-nopreempt-AMDGPU-dav9 #1 [68812.480464] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [68812.480469] CacheThread_Blo D 0 9414 9082 0x00000080 [68812.480476] Call Trace: [68812.480494] __schedule+0x29e/0x6c0 [68812.480505] schedule+0x32/0x80 [68812.480513] schedule_preempt_disabled+0xa/0x10 [68812.480520] __mutex_lock.isra.1+0x26b/0x4e0 [68812.480550] ? do_journal_begin_r+0xbe/0x390 [reiserfs] [68812.480570] do_journal_begin_r+0xbe/0x390 [reiserfs] [68812.480586] ? __switch_to_asm+0x35/0x70 [68812.480588] ? __switch_to_asm+0x41/0x70 [68812.480590] ? __switch_to_asm+0x35/0x70 [68812.480592] ? __switch_to_asm+0x41/0x70 [68812.480593] ? __switch_to_asm+0x35/0x70 [68812.480595] ? __switch_to_asm+0x41/0x70 [68812.480597] ? __switch_to_asm+0x35/0x70 [68812.480601] journal_begin+0x80/0x140 [reiserfs] [68812.480606] reiserfs_dirty_inode+0x3d/0xa0 [reiserfs] [68812.480609] ? __switch_to+0x1ee/0x3f0 [68812.480610] ? __switch_to+0x1ee/0x3f0 [68812.480612] __mark_inode_dirty+0x163/0x350 [68812.480615] generic_update_time+0x79/0xc0 [68812.480617] ? current_time+0x38/0x70 [68812.480619] file_update_time+0xbe/0x110 [68812.480622] __generic_file_write_iter+0x99/0x1b0 [68812.480624] generic_file_write_iter+0xe2/0x1c0 [68812.480626] __vfs_write+0x102/0x180 [68812.480628] vfs_write+0xb0/0x190 [68812.480630] SyS_pwrite64+0x90/0xb0 [68812.480632] do_syscall_64+0x6e/0x110 [68812.480634] entry_SYSCALL_64_after_hwframe+0x41/0xa6 [68812.480637] RIP: 0033:0x7f8a92976983 [68812.480638] RSP: 002b:00007f8a779e1630 EFLAGS: 00000293 ORIG_RAX: 0000000000000012 [68812.480640] RAX: ffffffffffffffda RBX: 00007f8a779e1640 RCX: 00007f8a92976983 [68812.480641] RDX: 0000000000000128 RSI: 000001790ddf3c00 RDI: 0000000000000040 [68812.480642] RBP: 00007f8a779e16f0 R08: 00007f8a779e1558 R09: 0000000000000001 [68812.480643] R10: 0000000000002000 R11: 0000000000000293 R12: 0000000000002000 [68812.480644] R13: 000001790a6b8dd0 R14: 000001790ddf3c00 R15: 0000000000000128 [68812.480647] INFO: task ThreadPoolSingl:9908 blocked for more than 480 seconds. 4.14.184 https://bugzilla.kernel.org/show_bug.cgi?id=208777 Thanks, David