From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out30-113.freemail.mail.aliyun.com (out30-113.freemail.mail.aliyun.com [115.124.30.113]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 8EA5113A258 for ; Thu, 3 Jul 2025 02:10:15 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=115.124.30.113 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1751508618; cv=none; b=svZe7tnfOqUuSsIv0NTZLi+rrB6cjFbVJhkv4kjC7GrR0WYHJMgXuTm2bMwnyapz/OVEiC8ITliZnMOZBR9NLiFb1aONBIUPg8/HQlNE1CEUQ0dT8FoKmuABak4F6pZA6hUHar/+5nBGld0LSqlcjzWQHOU9SG8lk3FGW3yKAuQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1751508618; c=relaxed/simple; bh=vwwNDJjzlQVohb13fx30SQfuyj8E8X58401NQAwwcMU=; h=From:To:Cc:Subject:Date:Message-Id:MIME-Version; b=lByRqU0JrYjHFtPSbgsHZTbK2SEwZztIioAw/K7M4GEw3MBgQBVasjUGxzkKawMoLnwk6h2zgV0wzT7V9b/9kXviNqwmhMv8mGk6i42IJZox+3T1I0gOk9A110Afj8hMWaNrRtA4I9d0yctCnWG4yTAqxTqyC4R+81d1pTrBa+c= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.alibaba.com; spf=pass smtp.mailfrom=linux.alibaba.com; dkim=pass (1024-bit key) header.d=linux.alibaba.com header.i=@linux.alibaba.com header.b=RjSEyhxY; arc=none smtp.client-ip=115.124.30.113 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.alibaba.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.alibaba.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.alibaba.com header.i=@linux.alibaba.com header.b="RjSEyhxY" DKIM-Signature:v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.alibaba.com; s=default; t=1751508606; h=From:To:Subject:Date:Message-Id:MIME-Version; bh=edvmugWDJTxNMlK+9JCcM+4eNkyAjcSLRhmeAsoFGzs=; b=RjSEyhxYbxAvZqPd4skuf3HNM5qYrdenFnHo1fllaLGOWYEQOEfOL0IgcMt5FChjtNuc3Sz8UfZwMVlGlAIz5/LokvZN5f8/iOGofXraLXCubov1m5TA/aKgpk9LT/TTkwDZNRL8qbgY2l8QHuO1CUweulF7dnF/3ZJViqUx2Uo= Received: from localhost(mailfrom:feng.tang@linux.alibaba.com fp:SMTPD_---0WgqZ3cs_1751508605 cluster:ay36) by smtp.aliyun-inc.com; Thu, 03 Jul 2025 10:10:05 +0800 From: Feng Tang To: Andrew Morton , Petr Mladek , Steven Rostedt , Lance Yang , Jonathan Corbet , linux-kernel@vger.kernel.org Cc: paulmck@kernel.org, john.ogness@linutronix.de, Feng Tang Subject: [PATCH v3 0/5] generalize panic_print's dump function to be used by other kernel parts Date: Thu, 3 Jul 2025 10:09:59 +0800 Message-Id: <20250703021004.42328-1-feng.tang@linux.alibaba.com> X-Mailer: git-send-email 2.39.5 (Apple Git-154) Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit When working on kernel stability issues, panic, task-hung and software/hardware lockup are frequently met. And to debug them, user may need lots of system information at that time, like task call stacks, lock info, memory info etc. panic case already has panic_print_sys_info() for this purpose, and has a 'panic_print' bitmask to control what kinds of information is needed, which is also helpful to debug other task-hung and lockup cases. So this patchset extract the function out to a new file 'lib/sys_info.c', and make it available for other cases which also need to dump system info for debugging. Also as suggested by Petr Mladek, add 'panic_sys_info=' interface to take human readable string like "tasks,mem,locks,timers,ftrace,....", and eventually obsolete the current 'panic_print' bitmap interface. In RFC and V1 version, hung_task and SW/HW watchdog modules are enabled with the new sys_info dump interface. In v2, they are kept out for better review of current change, and will be posted later. Locally these have been used in our bug chasing for stability issues and was proven helpful. Many thanks to Petr Mladek for great suggestions on both the code and architectures! - Feng One to do left is about adding note for obsoleting 'panic_print' cmdline as discussed in https://lore.kernel.org/lkml/aFvBuOnD0cAEWJfl@U-2FWC9VHC-2323.local/ and will be posted later. Changelog: Since v2: * Rename to PANIC_CONSOLE_REPLAY (Petr Mladek) * Don't let kernel.h include sys_info.h (Petr Mladek) * Improve documents and coding style (Petr Mladek/Lance Yang) * Add 'panic_console_replay' parameter (Petr Mladek) * Fix compiling problem (0Day bot) * Add reviewed-by tag from Petr for patch 1/5 Since V1: * Separate the 'sys_show_info' related code to new file sys_info.[ch] (Petr Mladek) * Clean up the code for panic console replay (Petr Mladek) * Add 'panic_sys_info=' cmdline and sysctl interface for taking human readable parameters (Petr Mladek) * Add note about the obsoleting of 'panic_print' (Petr Mladek) * Hold the changes to hungtask/watchdog Since RFC: * Don't print all cpu backtrace if 'sysctl_hung_task_all_cpu_backtracemay' is 'false' (Lance Yang) * Change the name of 2 new kernel control knob to have 'mask' inside, and add kernel document and code comments for them (Lance Yang) * Make the sys_show_info() support printk msg replay and all CPU backtrace. Feng Tang (5): panic: clean up code for console replay panic: generalize panic_print's function to show sys info panic: add 'panic_sys_info' sysctl to take human readable string parameter panic: add 'panic_sys_info=' setup option for kernel cmdline panic: add note that panic_print sysctl interface is deprecated .../admin-guide/kernel-parameters.txt | 21 ++- Documentation/admin-guide/sysctl/kernel.rst | 20 ++- include/linux/sys_info.h | 27 ++++ kernel/panic.c | 71 +++++----- lib/Makefile | 2 +- lib/sys_info.c | 122 ++++++++++++++++++ 6 files changed, 221 insertions(+), 42 deletions(-) create mode 100644 include/linux/sys_info.h create mode 100644 lib/sys_info.c -- 2.43.5