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=-8.6 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 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 A0CB0C5DF62 for ; Wed, 6 Nov 2019 13:25:25 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 6279021D7E for ; Wed, 6 Nov 2019 13:25:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1573046725; bh=uv8hUmh6ncxpuKvxrxfi4R6VPvr+dCvkWzsGjjJTEC8=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=RqvYOjio2k+Zj3hd+UbU4ccI2P4QeLI5Fk1w79am8RQvR/dYs0kC7q82qZGle/dls 1lDtoJSXgFUI8w39uQNcpL944I36MLwHd0LwIHwRIwm8njbBIo+2L8ZzN3EW0SJvcv fhmUNMGHQggnzbtXiXAcb5NihNfz/Wfw2MSi8xvk= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731545AbfKFNZY (ORCPT ); Wed, 6 Nov 2019 08:25:24 -0500 Received: from mail.kernel.org ([198.145.29.99]:48482 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730878AbfKFNZX (ORCPT ); Wed, 6 Nov 2019 08:25:23 -0500 Received: from willie-the-truck (236.31.169.217.in-addr.arpa [217.169.31.236]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 3D3EA21D7F; Wed, 6 Nov 2019 13:25:20 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1573046722; bh=uv8hUmh6ncxpuKvxrxfi4R6VPvr+dCvkWzsGjjJTEC8=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=pcAR6fNJha9ieBKnJHttNjn+7tKtiaWUhgLYjUFs7st2ied/tjEb3nDJYWcHwIa8Z si4qk8wAMhoT1OLUwot7OMn7TMrzTia3LB2Y94iaO+TlhwSeazyD9ZfUA/1sWsniAb 4RYOLS2bmE2krTU+GKDHOC8Q4sLJ1UkhUvclZ3oo= Date: Wed, 6 Nov 2019 13:25:17 +0000 From: Will Deacon To: Dmitry Safonov Cc: linux-kernel@vger.kernel.org, Dmitry Safonov <0x7f454c46@gmail.com>, Andrew Morton , Greg Kroah-Hartman , Ingo Molnar , Jiri Slaby , Petr Mladek , Sergey Senozhatsky , Steven Rostedt , Tetsuo Handa , Catalin Marinas , Russell King , linux-arm-kernel@lists.infradead.org Subject: Re: [PATCH 09/50] arm64: Add loglvl to dump_backtrace() Message-ID: <20191106132516.GC5808@willie-the-truck> References: <20191106030542.868541-1-dima@arista.com> <20191106030542.868541-10-dima@arista.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20191106030542.868541-10-dima@arista.com> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Nov 06, 2019 at 03:05:00AM +0000, Dmitry Safonov wrote: > Currently, the log-level of show_stack() depends on a platform > realization. It creates situations where the headers are printed with > lower log level or higher than the stacktrace (depending on > a platform or user). > > Furthermore, it forces the logic decision from user to an architecture > side. In result, some users as sysrq/kdb/etc are doing tricks with > temporary rising console_loglevel while printing their messages. > And in result it not only may print unwanted messages from other CPUs, > but also omit printing at all in the unlucky case where the printk() > was deferred. > > Introducing log-level parameter and KERN_UNSUPPRESSED [1] seems > an easier approach than introducing more printk buffers. > Also, it will consolidate printings with headers. > > Add log level argument to dump_backtrace() as a preparation for > introducing show_stack_loglvl(). > > Cc: Catalin Marinas > Cc: Russell King > Cc: Will Deacon > Cc: linux-arm-kernel@lists.infradead.org > [1]: https://lore.kernel.org/lkml/20190528002412.1625-1-dima@arista.com/T/#u > Signed-off-by: Dmitry Safonov > --- > arch/arm64/include/asm/stacktrace.h | 3 ++- > arch/arm64/kernel/process.c | 2 +- > arch/arm64/kernel/traps.c | 17 +++++++++-------- > 3 files changed, 12 insertions(+), 10 deletions(-) [...] > diff --git a/arch/arm64/kernel/traps.c b/arch/arm64/kernel/traps.c > index 34739e80211b..59072c7b9fb4 100644 > --- a/arch/arm64/kernel/traps.c > +++ b/arch/arm64/kernel/traps.c > @@ -52,9 +52,9 @@ static const char *handler[]= { > > int show_unhandled_signals = 0; > > -static void dump_backtrace_entry(unsigned long where) > +static void dump_backtrace_entry(unsigned long where, const char *loglvl) > { > - printk(" %pS\n", (void *)where); > + printk("%s %pS\n", loglvl, (void *)where); > } > > static void dump_kernel_instr(const char *lvl, struct pt_regs *regs) > @@ -82,12 +82,13 @@ static void dump_kernel_instr(const char *lvl, struct pt_regs *regs) > printk("%sCode: %s\n", lvl, str); > } > > -void dump_backtrace(struct pt_regs *regs, struct task_struct *tsk) > +void dump_backtrace(struct pt_regs *regs, struct task_struct *tsk, > + const char *loglvl) > { > struct stackframe frame; > int skip = 0; > > - pr_debug("%s(regs = %p tsk = %p)\n", __func__, regs, tsk); > + printk("%s%s(regs = %p tsk = %p)\n", loglvl, __func__, regs, tsk); This one needs to stay as pr_debug(). Will