From mboxrd@z Thu Jan 1 00:00:00 1970 Received: with ECARTIS (v1.0.0; list linux-mips); Mon, 16 Jul 2018 09:40:07 +0200 (CEST) Received: from mail.linuxfoundation.org ([140.211.169.12]:37772 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by eddie.linux-mips.org with ESMTP id S23994587AbeGPHj6cUE2t (ORCPT ); Mon, 16 Jul 2018 09:39:58 +0200 Received: from localhost (LFbn-1-12247-202.w90-92.abo.wanadoo.fr [90.92.61.202]) by mail.linuxfoundation.org (Postfix) with ESMTPSA id 0170DC03; Mon, 16 Jul 2018 07:39:51 +0000 (UTC) From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Paul Burton , James Hogan , Ralf Baechle , Huacai Chen , linux-mips@linux-mips.org Subject: [PATCH 4.14 03/54] MIPS: Call dump_stack() from show_regs() Date: Mon, 16 Jul 2018 09:35:00 +0200 Message-Id: <20180716073451.016568406@linuxfoundation.org> X-Mailer: git-send-email 2.18.0 In-Reply-To: <20180716073450.534886211@linuxfoundation.org> References: <20180716073450.534886211@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Return-Path: X-Envelope-To: <"|/home/ecartis/ecartis -s linux-mips"> (uid 0) X-Orcpt: rfc822;linux-mips@linux-mips.org Original-Recipient: rfc822;linux-mips@linux-mips.org X-archive-position: 64843 X-ecartis-version: Ecartis v1.0.0 Sender: linux-mips-bounce@linux-mips.org Errors-to: linux-mips-bounce@linux-mips.org X-original-sender: gregkh@linuxfoundation.org Precedence: bulk List-help: List-unsubscribe: List-software: Ecartis version 1.0.0 List-Id: linux-mips X-List-ID: linux-mips List-subscribe: List-owner: List-post: List-archive: X-list: linux-mips 4.14-stable review patch. If anyone has any objections, please let me know. ------------------ From: Paul Burton commit 5a267832c2ec47b2dad0fdb291a96bb5b8869315 upstream. The generic nmi_cpu_backtrace() function calls show_regs() when a struct pt_regs is available, and dump_stack() otherwise. If we were to make use of the generic nmi_cpu_backtrace() with MIPS' current implementation of show_regs() this would mean that we see only register data with no accompanying stack information, in contrast with our current implementation which calls dump_stack() regardless of whether register state is available. In preparation for making use of the generic nmi_cpu_backtrace() to implement arch_trigger_cpumask_backtrace(), have our implementation of show_regs() call dump_stack() and drop the explicit dump_stack() call in arch_dump_stack() which is invoked by arch_trigger_cpumask_backtrace(). This will allow the output we produce to remain the same after a later patch switches to using nmi_cpu_backtrace(). It may mean that we produce extra stack output in other uses of show_regs(), but this: 1) Seems harmless. 2) Is good for consistency between arch_trigger_cpumask_backtrace() and other users of show_regs(). 3) Matches the behaviour of the ARM & PowerPC architectures. Marked for stable back to v4.9 as a prerequisite of the following patch "MIPS: Call dump_stack() from show_regs()". Signed-off-by: Paul Burton Patchwork: https://patchwork.linux-mips.org/patch/19596/ Cc: James Hogan Cc: Ralf Baechle Cc: Huacai Chen Cc: linux-mips@linux-mips.org Cc: stable@vger.kernel.org # v4.9+ Signed-off-by: Greg Kroah-Hartman --- arch/mips/kernel/process.c | 4 ++-- arch/mips/kernel/traps.c | 1 + 2 files changed, 3 insertions(+), 2 deletions(-) --- a/arch/mips/kernel/process.c +++ b/arch/mips/kernel/process.c @@ -663,8 +663,8 @@ static void arch_dump_stack(void *info) if (regs) show_regs(regs); - - dump_stack(); + else + dump_stack(); } void arch_trigger_cpumask_backtrace(const cpumask_t *mask, bool exclude_self) --- a/arch/mips/kernel/traps.c +++ b/arch/mips/kernel/traps.c @@ -351,6 +351,7 @@ static void __show_regs(const struct pt_ void show_regs(struct pt_regs *regs) { __show_regs((struct pt_regs *)regs); + dump_stack(); } void show_registers(struct pt_regs *regs)