From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out-170.mta0.migadu.com (out-170.mta0.migadu.com [91.218.175.170]) (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 883AC22B8C5 for ; Thu, 3 Jul 2025 03:23:41 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=91.218.175.170 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1751513025; cv=none; b=QxNLv9nT52ZmXHvgSVagr7DjEEu0lGjatZkhHe/TcwAXp67pGitlt7fX8nRaHUhyj+o+vGlxfA6OHKEAK/qBGWSyxRHXby1bftUQSQVbynKrGtA/GnL2qvi3FJQFcLGIHWTO1GKwBIh613wQPxFXXU9fjRHbPYXbuwdNNjwG5uQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1751513025; c=relaxed/simple; bh=ZERNRpXu+O9L8hzxBmJsquggruQ2OePikz7yoCgMaRc=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=U0L66gsbl75RQolY23WNEn0ibMvhUtqqERRE+pSrSbAXJ8vRzEjNOQLscf2s4fyHryC9RNGxTIoGHNnrMj3c4/VJkbNzLO7u0i3N+QK1ApmT0TpalSpZUGdxVu1UEAc+ucTUB0VdDsolf+RCFz/pflT/eQXR7DVKWCPsFMczlsk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b=XqRlNRDi; arc=none smtp.client-ip=91.218.175.170 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b="XqRlNRDi" Message-ID: <5f4f048e-02ff-4669-b4b1-e411c6be536b@linux.dev> DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1751513019; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=02Z56k5zvMHyfb242f86xyhwrkS4NA9iR003Aq/JcII=; b=XqRlNRDinGAVovYfLF3OPit+0XuQ9nfTEYK01MdmtohibmluJ0UcGwC+09A09/7mho5H+u LfZIKd29oZO3RSSGxXeONGCes6nZbQbeo2Wy9AKQVUhzk4ddVqtirrUcicgeFGVquo3SoE 37IoBEaeQMTbeV1Mg26yStntpW9lc10= Date: Thu, 3 Jul 2025 11:23:32 +0800 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Subject: Re: [PATCH v3 0/5] generalize panic_print's dump function to be used by other kernel parts Content-Language: en-US To: Feng Tang Cc: paulmck@kernel.org, john.ogness@linutronix.de, Andrew Morton , Steven Rostedt , Petr Mladek , Jonathan Corbet , linux-kernel@vger.kernel.org References: <20250703021004.42328-1-feng.tang@linux.alibaba.com> X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. From: Lance Yang In-Reply-To: <20250703021004.42328-1-feng.tang@linux.alibaba.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit X-Migadu-Flow: FLOW_OUT Just hit a build failure with this patch series when building for arm64 with a minimal configuration: kernel/panic.c: In function ‘setup_panic_sys_info’: kernel/panic.c:151:23: error: implicit declaration of function ‘sys_info_parse_param’ [-Wimplicit-function-declaration] 151 | panic_print = sys_info_parse_param(buf); | ^~~~~~~~~~~~~~~~~~~~ make[3]: *** [scripts/Makefile.build:287: kernel/panic.o] Error 1 make[2]: *** [scripts/Makefile.build:554: kernel] Error 2 To reproduce it: $ make ARCH=arm64 allnoconfig $ make ARCH=arm64 -j$(nproc) Thanks, Lance On 2025/7/3 10:09, Feng Tang wrote: > 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 >