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=-4.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT 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 BFA2EC433DF for ; Tue, 23 Jun 2020 16:30:07 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9782220780 for ; Tue, 23 Jun 2020 16:30:07 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=arista.com header.i=@arista.com header.b="cl7AT4Tz" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732610AbgFWQaG (ORCPT ); Tue, 23 Jun 2020 12:30:06 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45006 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1732224AbgFWQaF (ORCPT ); Tue, 23 Jun 2020 12:30:05 -0400 Received: from mail-pl1-x642.google.com (mail-pl1-x642.google.com [IPv6:2607:f8b0:4864:20::642]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9A7AAC061573 for ; Tue, 23 Jun 2020 09:30:05 -0700 (PDT) Received: by mail-pl1-x642.google.com with SMTP id y18so9335716plr.4 for ; Tue, 23 Jun 2020 09:30:05 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=arista.com; s=googlenew; h=from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=SvUlmAgaOlEv+y6BanvWiE6s1/Lag7n3+CMI66JEh+s=; b=cl7AT4Tzf+CETjubxfkcvaSJGN1BK2c+PDYZWzfJd/GQWfsVwbzD11f+2BSsR/UMAW 2HuX4QZhVgcGtjHuERO5y2WLxw+ij/sVm0BeraELAqhPpEKXzG8qp6/Ciuc2wqMetHrV +2Wh8soczDp85b5vDx/MwtqcKxL1Lj3XenYiE/pRsngBxVqJ1r+8TuvjfnVMrlwJXQH8 RUWRBWcRX+TugGxQPAKRq50Tw1WVKBf6rjlq4ujNCkUwr1dviAtMvhQUEgZbWtNdapJo LE9DTztHP6H4ikW+DGwo4VIYNlwf/r2pA6koJGmiAMOt07XhIY+F00yVLavxajCpfQ6S ding== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=SvUlmAgaOlEv+y6BanvWiE6s1/Lag7n3+CMI66JEh+s=; b=HCcV391Jl20Q3hRAX2VKmNwGgH4dFDpDisbiTBkJNEyt1eK+b0Jc1xvXdwU4NhHgSi w7EGI3i4PzOUyWLV/ZRgnAaM9Qzfl6BEaOm/mMQpXc/yO+1mjOvJIu2eSYhLWzT1pGup 77O9LDcWuZgCeNq0RYsrauoSqsIJUKHnj5jvh1+pndXF0eRL/0igOFwM1VJt0VDswyww nXlmy8PaZPD51sD2fgTR+dGh71q898IfgKoFXalTbANXrSQH+l0UIj8hVhgSkfwSk1qr DuqWOJ/vpfUrY97BO81CwDoEUmIYFVW4JPery4q2FBHA3EIVjLsjGBffR/13QvDuWWDo NArg== X-Gm-Message-State: AOAM530jr8BDKcNbOS4YQOHgq1D+OMAYamlOqjJrsK+qHx/vTQyC5BcT CLaK/PVAZkTwSQNv3P2rH4/G3eGA4ddBSK8L X-Google-Smtp-Source: ABdhPJxSB4oaPmGIoV7um96NDP/GdLDz8c1l+Lz6Z0yO1fcqTpNHP7WLMOBV4G7cZ7I6MkN9Ll/Zvw== X-Received: by 2002:a17:90a:bf0b:: with SMTP id c11mr25108576pjs.47.1592929804491; Tue, 23 Jun 2020 09:30:04 -0700 (PDT) Received: from Mindolluin.aristanetworks.com ([2a02:8084:e84:2480:228:f8ff:fe6f:83a8]) by smtp.gmail.com with ESMTPSA id n12sm13753969pgr.88.2020.06.23.09.30.00 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 23 Jun 2020 09:30:03 -0700 (PDT) From: Dmitry Safonov To: linux-kernel@vger.kernel.org Cc: Dmitry Safonov <0x7f454c46@gmail.com>, Dmitry Safonov , Andy Lutomirski , Borislav Petkov , "H. Peter Anvin" , Ingo Molnar , Jann Horn , Petr Mladek , Sergey Senozhatsky , Steven Rostedt , Tetsuo Handa , Thomas Gleixner , x86@kernel.org Subject: [PATCH 0/3] x86/dumpstack: Print registers with the same log level as the backtrace Date: Tue, 23 Jun 2020 17:29:55 +0100 Message-Id: <20200623162958.331051-1-dima@arista.com> X-Mailer: git-send-email 2.27.0 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org show_trace_log_lvl() provides x86 platform-specific way to unwind backtrace with a given log level. Unfortunately, registers dump(s) are not printed with the same log level - instead, KERN_DEFAULT is always used. Arista's switches uses quite common setup with rsyslog, where only urgent messages goes to console (console_log_level=KERN_ERR), everything else goes into /var/log/ as the console baud-rate often is indecently slow (9600 bps). Backtrace dumps without registers printed have proven to be as useful as morning standups. Furthermore, in order to introduce KERN_UNSUPPRESSED (which I believe is still the most elegant way to fix raciness of sysrq[1]) the log level should be passed down the stack to register dumping functions. Besides, I have a potential use-case for printing traces with KERN_DEBUG level [2] (where registers dump shouldn't appear with higher log level than the backtrace). Cc: Andy Lutomirski Cc: Borislav Petkov Cc: "H. Peter Anvin" Cc: Ingo Molnar Cc: Jann Horn Cc: Petr Mladek Cc: Sergey Senozhatsky Cc: Steven Rostedt Cc: Tetsuo Handa Cc: Thomas Gleixner Cc: x86@kernel.org [1]: https://lore.kernel.org/lkml/20190528002412.1625-1-dima@arista.com/ [2]: https://lore.kernel.org/linux-doc/20190724170249.9644-1-dima@arista.com/ Dmitry Safonov (3): x86/dumpstack: Add log_lvl to show_iret_regs() x86/dumpstack: Add log_lvl to __show_regs() x86/dumpstack: Show registers dump with trace's log level arch/x86/include/asm/kdebug.h | 5 ++-- arch/x86/kernel/dumpstack.c | 23 +++++++++------- arch/x86/kernel/process_32.c | 29 ++++++++++---------- arch/x86/kernel/process_64.c | 51 ++++++++++++++++++----------------- 4 files changed, 57 insertions(+), 51 deletions(-) -- 2.27.0