Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753699AbbGXBVN (ORCPT ); Thu, 23 Jul 2015 21:21:13 -0400 Received: from mail7.hitachi.co.jp ([133.145.228.42]:36484 "EHLO mail7.hitachi.co.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753288AbbGXBVL (ORCPT ); Thu, 23 Jul 2015 21:21:11 -0400 X-AuditID: 85900ec0-9d7c9b9000001a57-6d-55b192d832aa X-Mailbox-Line: From nobody Fri Jul 24 10:16:15 2015 Subject: [RFC V2 PATCH 0/1] kexec: crash_kexec_post_notifiers boot option related fixes To: Andrew Morton , "Eric W. Biederman" , Vivek Goyal From: Hidehiro Kawai Cc: linux-mips@linux-mips.org, Baoquan He , kexec@lists.infradead.org, linux-kernel@vger.kernel.org, HATAYAMA Daisuke , Masami Hiramatsu , Daniel Walker , Ingo Molnar Date: Fri, 24 Jul 2015 10:16:15 +0900 Message-ID: <20150724011615.6834.79628.stgit@softrs> User-Agent: StGit/0.16 MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit X-Brightmail-Tracker: AAAAAA== Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2052 Lines: 60 This is a bugfix patch for crash_kexec_post_notifiers boot option which allows users to call panic notifiers and kmsg dumpers before kdump. This fixes one of the problems reported by Daniel Walker (https://lkml.org/lkml/2015/6/24/44). Problem 1: If crash_kexec_post_notifiers boot option is specified, some shutting down process which assume other cpus are still alive don't work properly. Problem 2 (addressed by this patch): If crash_kexec_post_notifiers boot option is specified, register information of other cpus are not saved to crash dumps. Following Vivek's opinion, this patch replaces smp_send_stop() in panic() with suitable version for crash_kexec which saves cpu states and other things like cleaning up VMX/SVM. Since this needs architecture specific implementation and it's not so trivial, this version only support for x86. So the problem 1, known to happen on MIPS/OCTEON, is not addressed now. To keep the modification impact low, this patch doesn't change the logic basically if crash_kexec_post_notifiers is not specified. Please note that crash_kexec() can be called directly without entering panic(). Stopping other cpus functionality is still needed in crash_kexec(). Changes in V2: - Replace smp_send_stop() call with crash_kexec version which saves cpu states and does cleanups instead of changing execution flow - Drop a fix for Problem 1 - Drop other patches because they aren't needed anymore V1: https://lkml.org/lkml/2015/7/10/316 --- Hidehiro Kawai (1): panic/x86: Replace smp_send_stop() with crash_kexec version arch/x86/kernel/crash.c | 16 +++++++++++----- kernel/panic.c | 29 +++++++++++++++++++++++------ 2 files changed, 34 insertions(+), 11 deletions(-) -- Hidehiro Kawai Hitachi, Ltd. Research & Development Group -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/