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=-6.8 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 4A406C5DF62 for ; Wed, 6 Nov 2019 09:53:02 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 16617217F4 for ; Wed, 6 Nov 2019 09:53:02 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=ellerman.id.au header.i=@ellerman.id.au header.b="b9gId18g" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731567AbfKFJxA (ORCPT ); Wed, 6 Nov 2019 04:53:00 -0500 Received: from bilbo.ozlabs.org ([203.11.71.1]:48425 "EHLO ozlabs.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726143AbfKFJxA (ORCPT ); Wed, 6 Nov 2019 04:53:00 -0500 Received: from authenticated.ozlabs.org (localhost [127.0.0.1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange ECDHE (P-256) server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by mail.ozlabs.org (Postfix) with ESMTPSA id 477MKM0M9xz9sP6; Wed, 6 Nov 2019 20:52:54 +1100 (AEDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=ellerman.id.au; s=201909; t=1573033977; bh=izSF2AL2NQDyQCu8234O8zrZSbgYgjyqHCG8/iEWwGs=; h=From:To:Cc:Subject:In-Reply-To:References:Date:From; b=b9gId18gagaVywR+++g4RbfioORzpLVEpkQFDfoe6YJ+Id1Hyjjq/06ICOZfwGQ7s uEw327gffeKFiSAHkylzMZ/SlvyUFoOtryquxAkEd7UwW0ywC33JL/TU521FoKipgm nmhtWZg0/lLCyrcslap1+XDAoBZSrMxItWvQ1SmJ9RNfGuYMWc2c3X59G7Im5DKs8u dmxP/7vER/jwGiOjnVMTWRO07UPpgf8NEYrfqsa0inOKOjfQLe+sscQL5S6RbDv/aq ZbSIdMDPaAr0Z/SRZSv1GMd4yPv/NNcs1Bjn+vaWsmgj+XcmuizMxkiy294kyreFAY 5s6eorQGvCfXg== From: Michael Ellerman To: Dmitry Safonov , linux-kernel@vger.kernel.org Cc: Dmitry Safonov <0x7f454c46@gmail.com>, Dmitry Safonov , Andrew Morton , Greg Kroah-Hartman , Ingo Molnar , Jiri Slaby , Petr Mladek , Sergey Senozhatsky , Steven Rostedt , Tetsuo Handa , Benjamin Herrenschmidt , Paul Mackerras , linuxppc-dev@lists.ozlabs.org Subject: Re: [PATCH 26/50] powerpc: Add show_stack_loglvl() In-Reply-To: <20191106030542.868541-27-dima@arista.com> References: <20191106030542.868541-1-dima@arista.com> <20191106030542.868541-27-dima@arista.com> Date: Wed, 06 Nov 2019 20:52:52 +1100 Message-ID: <8736f172mj.fsf@mpe.ellerman.id.au> MIME-Version: 1.0 Content-Type: text/plain Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Dmitry Safonov writes: > 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). Yes, I've had bug reports where the stacktrace is missing, which is annoying. Thanks for trying to fix the problem. > 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. > > Introduce show_stack_loglvl(), that eventually will substitute > show_stack(). > > Cc: Benjamin Herrenschmidt > Cc: Michael Ellerman > Cc: Paul Mackerras > Cc: linuxppc-dev@lists.ozlabs.org > [1]: https://lore.kernel.org/lkml/20190528002412.1625-1-dima@arista.com/T/#u > Signed-off-by: Dmitry Safonov > --- > arch/powerpc/kernel/process.c | 18 +++++++++++++----- > 1 file changed, 13 insertions(+), 5 deletions(-) This looks good to me. Acked-by: Michael Ellerman (powerpc) cheers > diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c > index 639ceae7da9d..34b46680a196 100644 > --- a/arch/powerpc/kernel/process.c > +++ b/arch/powerpc/kernel/process.c > @@ -2028,7 +2028,8 @@ unsigned long get_wchan(struct task_struct *p) > > static int kstack_depth_to_print = CONFIG_PRINT_STACK_DEPTH; > > -void show_stack(struct task_struct *tsk, unsigned long *stack) > +void show_stack_loglvl(struct task_struct *tsk, unsigned long *stack, > + const char *loglvl) > { > unsigned long sp, ip, lr, newsp; > int count = 0; > @@ -2053,7 +2054,7 @@ void show_stack(struct task_struct *tsk, unsigned long *stack) > } > > lr = 0; > - printk("Call Trace:\n"); > + printk("%sCall Trace:\n", loglvl); > do { > if (!validate_sp(sp, tsk, STACK_FRAME_OVERHEAD)) > break; > @@ -2062,7 +2063,8 @@ void show_stack(struct task_struct *tsk, unsigned long *stack) > newsp = stack[0]; > ip = stack[STACK_FRAME_LR_SAVE]; > if (!firstframe || ip != lr) { > - printk("["REG"] ["REG"] %pS", sp, ip, (void *)ip); > + printk("%s["REG"] ["REG"] %pS", > + loglvl, sp, ip, (void *)ip); > #ifdef CONFIG_FUNCTION_GRAPH_TRACER > ret_addr = ftrace_graph_ret_addr(current, > &ftrace_idx, ip, stack); > @@ -2084,8 +2086,9 @@ void show_stack(struct task_struct *tsk, unsigned long *stack) > struct pt_regs *regs = (struct pt_regs *) > (sp + STACK_FRAME_OVERHEAD); > lr = regs->link; > - printk("--- interrupt: %lx at %pS\n LR = %pS\n", > - regs->trap, (void *)regs->nip, (void *)lr); > + printk("%s--- interrupt: %lx at %pS\n LR = %pS\n", > + loglvl, regs->trap, > + (void *)regs->nip, (void *)lr); > firstframe = 1; > } > > @@ -2095,6 +2098,11 @@ void show_stack(struct task_struct *tsk, unsigned long *stack) > put_task_stack(tsk); > } > > +void show_stack(struct task_struct *tsk, unsigned long *stack) > +{ > + show_stack_loglvl(tsk, stack, KERN_DEFAULT); > +} > + > #ifdef CONFIG_PPC64 > /* Called with hard IRQs off */ > void notrace __ppc64_runlatch_on(void) > -- > 2.23.0