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=-15.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=ham 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 F098BC11F65 for ; Tue, 29 Jun 2021 02:40:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D946561D13 for ; Tue, 29 Jun 2021 02:40:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231332AbhF2Cm6 (ORCPT ); Mon, 28 Jun 2021 22:42:58 -0400 Received: from mail.kernel.org ([198.145.29.99]:35246 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230152AbhF2Cm6 (ORCPT ); Mon, 28 Jun 2021 22:42:58 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 77FF461D0C; Tue, 29 Jun 2021 02:40:30 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1624934430; bh=my3oSbLjGzoJueqZAXcoiBN1OEWQvjUNyNR4NpH8q7E=; h=Date:From:To:Subject:In-Reply-To:From; b=Nmd3QUMIHK2wnPDRFvDBOO4G2WdK7RS6FsI7JFMO21lHHoru0wqeePw80/l9Q/pix 0y0+J+h6vsfXu300i5OJQNjp9ZaxaRD2hg4X70TNXpjW4Q/Dg7M7tHMS2KCbwOMKB9 ydQ/iET3WtZAfbjiDiusSEW3IslBH1oGIjZTW4ns= Date: Mon, 28 Jun 2021 19:40:30 -0700 From: Andrew Morton To: akpm@linux-foundation.org, bo.he@intel.com, dvyukov@google.com, elver@google.com, glider@google.com, linux-mm@kvack.org, mingo@kernel.org, mm-commits@vger.kernel.org, pmladek@suse.com, psodagud@quicinc.com, rostedt@goodmis.org, ryabinin.a.a@gmail.com, senozhatsky@chromium.org, torvalds@linux-foundation.org, yanmin_zhang@linux.intel.com Subject: [patch 138/192] printk: introduce dump_stack_lvl() Message-ID: <20210629024030.7_lNcozaJ%akpm@linux-foundation.org> In-Reply-To: <20210628193256.008961950a714730751c1423@linux-foundation.org> User-Agent: s-nail v14.8.16 Precedence: bulk Reply-To: linux-kernel@vger.kernel.org List-ID: X-Mailing-List: mm-commits@vger.kernel.org From: Alexander Potapenko Subject: printk: introduce dump_stack_lvl() dump_stack() is used for many different cases, which may require a log level consistent with other kernel messages surrounding the dump_stack() call. Without that, certain systems that are configured to ignore the default level messages will miss stack traces in critical error reports. This patch introduces dump_stack_lvl() that behaves similarly to dump_stack(), but accepts a custom log level. The old dump_stack() becomes equal to dump_stack_lvl(KERN_DEFAULT). A somewhat similar patch has been proposed in 2012: https://lore.kernel.org/lkml/1332493269.2359.9.camel@hebo/ , but wasn't merged. [elver@google.com: add missing dump_stack_lvl() stub if CONFIG_PRINTK=n] Link: https://lkml.kernel.org/r/YJ0KAM0hQev1AmWe@elver.google.com Link: https://lkml.kernel.org/r/20210506105405.3535023-1-glider@google.com Signed-off-by: Alexander Potapenko Reviewed-by: Marco Elver Cc: Petr Mladek Cc: Ingo Molnar Cc: he, bo Cc: Yanmin Zhang Cc: Prasad Sodagudi Cc: Dmitry Vyukov Cc: Sergey Senozhatsky Cc: Steven Rostedt Cc: Andrey Ryabinin Signed-off-by: Andrew Morton --- include/linux/printk.h | 5 +++++ lib/dump_stack.c | 20 +++++++++++++------- 2 files changed, 18 insertions(+), 7 deletions(-) --- a/include/linux/printk.h~printk-introduce-dump_stack_lvl +++ a/include/linux/printk.h @@ -206,6 +206,7 @@ void __init setup_log_buf(int early); __printf(1, 2) void dump_stack_set_arch_desc(const char *fmt, ...); void dump_stack_print_info(const char *log_lvl); void show_regs_print_info(const char *log_lvl); +extern asmlinkage void dump_stack_lvl(const char *log_lvl) __cold; extern asmlinkage void dump_stack(void) __cold; extern void printk_safe_flush(void); extern void printk_safe_flush_on_panic(void); @@ -269,6 +270,10 @@ static inline void show_regs_print_info( { } +static inline void dump_stack_lvl(const char *log_lvl) +{ +} + static inline void dump_stack(void) { } --- a/lib/dump_stack.c~printk-introduce-dump_stack_lvl +++ a/lib/dump_stack.c @@ -73,10 +73,10 @@ void show_regs_print_info(const char *lo dump_stack_print_info(log_lvl); } -static void __dump_stack(void) +static void __dump_stack(const char *log_lvl) { - dump_stack_print_info(KERN_DEFAULT); - show_stack(NULL, NULL, KERN_DEFAULT); + dump_stack_print_info(log_lvl); + show_stack(NULL, NULL, log_lvl); } /** @@ -87,7 +87,7 @@ static void __dump_stack(void) #ifdef CONFIG_SMP static atomic_t dump_lock = ATOMIC_INIT(-1); -asmlinkage __visible void dump_stack(void) +asmlinkage __visible void dump_stack_lvl(const char *log_lvl) { unsigned long flags; int was_locked; @@ -117,7 +117,7 @@ retry: goto retry; } - __dump_stack(); + __dump_stack(log_lvl); if (!was_locked) atomic_set(&dump_lock, -1); @@ -125,9 +125,15 @@ retry: local_irq_restore(flags); } #else -asmlinkage __visible void dump_stack(void) +asmlinkage __visible void dump_stack_lvl(const char *log_lvl) { - __dump_stack(); + __dump_stack(log_lvl); } #endif +EXPORT_SYMBOL(dump_stack_lvl); + +asmlinkage __visible void dump_stack(void) +{ + dump_stack_lvl(KERN_DEFAULT); +} EXPORT_SYMBOL(dump_stack); _