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=-9.9 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,UNPARSEABLE_RELAY, 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 6A28DECE587 for ; Tue, 1 Oct 2019 15:17:08 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 3A0C62133F for ; Tue, 1 Oct 2019 15:17:08 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=oracle.com header.i=@oracle.com header.b="D7dJqcMa" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2389493AbfJAPRH (ORCPT ); Tue, 1 Oct 2019 11:17:07 -0400 Received: from userp2120.oracle.com ([156.151.31.85]:38908 "EHLO userp2120.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2389175AbfJAPRH (ORCPT ); Tue, 1 Oct 2019 11:17:07 -0400 Received: from pps.filterd (userp2120.oracle.com [127.0.0.1]) by userp2120.oracle.com (8.16.0.27/8.16.0.27) with SMTP id x91FDk5A161443; Tue, 1 Oct 2019 15:16:58 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.com; h=from : to : cc : subject : date : message-id : mime-version : content-transfer-encoding; s=corp-2019-08-05; bh=Cl6NTVoaJaSBxqb2QcFNk13Sq3UWtVzalNOzurAnyF4=; b=D7dJqcMa/TH7rlsI4YA3nfkLmOEGuG6OjIc4axgqDw1FHCIBmQKLWjEzTOjp/DFTx6Eo ctOxQPyKguGydMvx2zKFl0zRbaMfIlpYe94hAsmOI5K38kdVUKxnqzNqLkUJ0+N4t2NS w68m/FwI73QiBcv+Kb6Qr+AQUFmyl889nJrPfFUOVAS3KX4EjrAt6YCxeYYKtRD3V106 wi8geTLcDENErs6iwAZKvI8P+pSTCZyAko1Cmg4Y1osISuXFo5vHwVkDIYZ5q4RYGMmV aPWMSXidqQyOYB459e0fzrcJhIl25hNhTbSaU88pQ1wmIKnnBeIM3KcHGpATsOnEXTUe Xw== Received: from userp3030.oracle.com (userp3030.oracle.com [156.151.31.80]) by userp2120.oracle.com with ESMTP id 2va05rpp81-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Tue, 01 Oct 2019 15:16:57 +0000 Received: from pps.filterd (userp3030.oracle.com [127.0.0.1]) by userp3030.oracle.com (8.16.0.27/8.16.0.27) with SMTP id x91FEL6J127106; Tue, 1 Oct 2019 15:16:57 GMT Received: from userv0121.oracle.com (userv0121.oracle.com [156.151.31.72]) by userp3030.oracle.com with ESMTP id 2vbmpysbdj-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Tue, 01 Oct 2019 15:16:56 +0000 Received: from abhmp0011.oracle.com (abhmp0011.oracle.com [141.146.116.17]) by userv0121.oracle.com (8.14.4/8.13.8) with ESMTP id x91FGs8p010956; Tue, 1 Oct 2019 15:16:55 GMT Received: from bostrovs-us.us.oracle.com (/10.152.32.65) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Tue, 01 Oct 2019 08:16:54 -0700 From: Boris Ostrovsky To: xen-devel@lists.xenproject.org, linux-kernel@vger.kernel.org Cc: jgross@suse.com, james@dingwall.me.uk, Boris Ostrovsky Subject: [PATCH] x86/xen: Return from panic notifier Date: Tue, 1 Oct 2019 11:16:33 -0400 Message-Id: <20191001151633.1659-1-boris.ostrovsky@oracle.com> X-Mailer: git-send-email 2.20.1 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9397 signatures=668685 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 suspectscore=0 malwarescore=0 phishscore=0 bulkscore=0 spamscore=0 mlxscore=0 mlxlogscore=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1908290000 definitions=main-1910010137 X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9397 signatures=668685 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 priorityscore=1501 malwarescore=0 suspectscore=0 phishscore=0 bulkscore=0 spamscore=0 clxscore=1015 lowpriorityscore=0 mlxscore=0 impostorscore=0 mlxlogscore=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1908290000 definitions=main-1910010137 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Currently execution of panic() continues until Xen's panic notifier (xen_panic_event()) is called at which point we make a hypercall that never returns. This means that any notifier that is supposed to be called later as well as significant part of panic() code (such as pstore writes from kmsg_dump()) is never executed. There is no reason for xen_panic_event() to be this last point in execution since panic()'s emergency_restart() will call into xen_emergency_restart() from where we can perform our hypercall. Reported-by: James Dingwall Signed-off-by: Boris Ostrovsky --- arch/x86/xen/enlighten.c | 17 ++++++++++++++--- 1 file changed, 14 insertions(+), 3 deletions(-) diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c index 750f46ad018a..fd4f58cf51dc 100644 --- a/arch/x86/xen/enlighten.c +++ b/arch/x86/xen/enlighten.c @@ -269,16 +269,27 @@ void xen_reboot(int reason) BUG(); } +static int reboot_reason = SHUTDOWN_reboot; void xen_emergency_restart(void) { - xen_reboot(SHUTDOWN_reboot); + xen_reboot(reboot_reason); } static int xen_panic_event(struct notifier_block *this, unsigned long event, void *ptr) { - if (!kexec_crash_loaded()) - xen_reboot(SHUTDOWN_crash); + if (!kexec_crash_loaded()) { + reboot_reason = SHUTDOWN_crash; + + /* + * If panic_timeout==0 then we are supposed to wait forever. + * However, to preserve original dom0 behavior we have to drop + * into hypervisor. (domU behavior is controlled by its + * config file) + */ + if (panic_timeout == 0) + panic_timeout = -1; + } return NOTIFY_DONE; } -- 2.17.1