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=-9.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,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 A5D7CC38A2C for ; Thu, 9 Apr 2020 09:54:18 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 67A70215A4 for ; Thu, 9 Apr 2020 09:38:45 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726678AbgDIJin (ORCPT ); Thu, 9 Apr 2020 05:38:43 -0400 Received: from m17617.mail.qiye.163.com ([59.111.176.17]:60715 "EHLO m17617.mail.qiye.163.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725997AbgDIJin (ORCPT ); Thu, 9 Apr 2020 05:38:43 -0400 Received: from wangqing-virtual-machine.localdomain (unknown [157.0.31.122]) by m17617.mail.qiye.163.com (Hmail) with ESMTPA id D770B26289F; Thu, 9 Apr 2020 17:38:36 +0800 (CST) From: Wang Qing To: Catalin Marinas , Will Deacon , Mark Rutland , James Morse , "Eric W. Biederman" , Thomas Gleixner , Wang Qing , jinho lim , Dave Martin , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Cc: opensource.kernel@vivo.com Subject: [PATCH] ARM64: fixed dump_backtrace() when task running on another cpu Date: Thu, 9 Apr 2020 17:38:16 +0800 Message-Id: <1586425106-7369-1-git-send-email-wangqing@vivo.com> X-Mailer: git-send-email 2.7.4 X-HM-Spam-Status: e1kfGhgUHx5ZQUtXWQgYFAkeWUFZT1VJS05CQkJDTkpJSU1DSllXWShZQU hPN1dZLVlBSVdZCQ4XHghZQVk1NCk2OjckKS43PlkG X-HM-Sender-Digest: e1kMHhlZQR0aFwgeV1kSHx4VD1lBWUc6OTI6ASo4MTg#GhYIPh5JThoQ CBIaCVFVSlVKTkNNT0lOSkpMSkxJVTMWGhIXVQwaFRwKEhUcOw0SDRRVGBQWRVlXWRILWUFZSk5M VUtVSEpVSklJWVdZCAFZQUlITk03Bg++ X-HM-Tid: 0a715e4e399d9375kuwsd770b26289f Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org We cannot get FP and PC when the task is running on another CPU, task->thread.cpu_context is the last time the task was switched out, it's better to give a reminder than to provide wrong information. Signed-off-by: Wang Qing --- arch/arm64/kernel/traps.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/arch/arm64/kernel/traps.c b/arch/arm64/kernel/traps.c index cf402be..c04e3e8 100644 --- a/arch/arm64/kernel/traps.c +++ b/arch/arm64/kernel/traps.c @@ -106,6 +106,14 @@ void dump_backtrace(struct pt_regs *regs, struct task_struct *tsk) start_backtrace(&frame, (unsigned long)__builtin_frame_address(0), (unsigned long)dump_backtrace); + } else if (tsk->on_cpu) { + /* + * The task is running in another cpu, so the call stack + * is changing and we cannot get it. + */ + pr_warn("tsk: %s is running in CPU%d, Don't call trace!\n", + tsk->comm, tsk->cpu); + return; } else { /* * task blocked in __switch_to -- 2.7.4