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=-9.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,USER_AGENT_GIT 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 0AFA1C43381 for ; Mon, 1 Apr 2019 10:47:30 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id DA2A92086C for ; Mon, 1 Apr 2019 10:47:29 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726752AbfDAKr2 (ORCPT ); Mon, 1 Apr 2019 06:47:28 -0400 Received: from mga09.intel.com ([134.134.136.24]:14977 "EHLO mga09.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725882AbfDAKr0 (ORCPT ); Mon, 1 Apr 2019 06:47:26 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga002.jf.intel.com ([10.7.209.21]) by orsmga102.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 01 Apr 2019 03:47:25 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.60,296,1549958400"; d="scan'208";a="146975627" Received: from shbuild999.sh.intel.com ([10.239.147.118]) by orsmga002.jf.intel.com with ESMTP; 01 Apr 2019 03:47:24 -0700 From: Feng Tang To: Andrew Morton , Petr Mladek , Steven Rostedt , Sergey Senozhatsky , linux-kernel@vger.kernel.org Cc: Kees Cook , Borislav Petkov , Feng Tang Subject: [PATCH 2/2] panic: Enable to print out all printk msg in buffer Date: Mon, 1 Apr 2019 18:48:04 +0800 Message-Id: <1554115684-26846-2-git-send-email-feng.tang@intel.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1554115684-26846-1-git-send-email-feng.tang@intel.com> References: <1554115684-26846-1-git-send-email-feng.tang@intel.com> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Currently on panic, kernel will lower the loglevel and print out new printk msg only. With this patch, user can configure the "panic_print" to see all dmesg in buffer, some of which they may have never seen due to the loglevel setting. Signed-off-by: Feng Tang --- Documentation/admin-guide/kernel-parameters.txt | 1 + kernel/panic.c | 9 ++++++++- 2 files changed, 9 insertions(+), 1 deletion(-) diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index 2b8ee90..7b15c94 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -3135,6 +3135,7 @@ bit 2: print timer info bit 3: print locks info if CONFIG_LOCKDEP is on bit 4: print ftrace buffer + bit 5: print all printk messages in buffer panic_on_warn panic() instead of WARN(). Useful to cause kdump on a WARN(). diff --git a/kernel/panic.c b/kernel/panic.c index fb77e01..afe023e 100644 --- a/kernel/panic.c +++ b/kernel/panic.c @@ -51,6 +51,7 @@ EXPORT_SYMBOL_GPL(panic_timeout); #define PANIC_PRINT_TIMER_INFO 0x00000004 #define PANIC_PRINT_LOCK_INFO 0x00000008 #define PANIC_PRINT_FTRACE_INFO 0x00000010 +#define PANIC_PRINT_ALL_PRINTK_MSG 0x00000020 unsigned long panic_print; ATOMIC_NOTIFIER_HEAD(panic_notifier_list); @@ -134,6 +135,13 @@ EXPORT_SYMBOL(nmi_panic); static void panic_print_sys_info(void) { + bool flush_all_dmesg = false; + + if (panic_print & PANIC_PRINT_ALL_PRINTK_MSG) + flush_all_dmesg = true; + + console_flush_on_panic(flush_all_dmesg); + if (panic_print & PANIC_PRINT_TASK_INFO) show_state(); @@ -277,7 +285,6 @@ void panic(const char *fmt, ...) * panic() is not being callled from OOPS. */ debug_locks_off(); - console_flush_on_panic(false); panic_print_sys_info(); -- 2.7.4