From patchwork Thu May 3 20:06:35 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: dann frazier X-Patchwork-Id: 908244 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=none (mailfrom) smtp.mailfrom=lists.ubuntu.com (client-ip=91.189.94.19; helo=huckleberry.canonical.com; envelope-from=kernel-team-bounces@lists.ubuntu.com; receiver=) Authentication-Results: ozlabs.org; dmarc=fail (p=none dis=none) header.from=canonical.com Received: from huckleberry.canonical.com (huckleberry.canonical.com [91.189.94.19]) by ozlabs.org (Postfix) with ESMTP id 40cR4d1L0Rz9s4r; Fri, 4 May 2018 06:06:57 +1000 (AEST) Received: from localhost ([127.0.0.1] helo=huckleberry.canonical.com) by huckleberry.canonical.com with esmtp (Exim 4.86_2) (envelope-from ) id 1fEKV4-0007ud-SR; Thu, 03 May 2018 20:06:46 +0000 Received: from complete.lackof.org ([198.49.126.79]) by huckleberry.canonical.com with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.86_2) (envelope-from ) id 1fEKV2-0007uS-3S for kernel-team@lists.ubuntu.com; Thu, 03 May 2018 20:06:44 +0000 Received: from localhost (c-73-78-137-212.hsd1.co.comcast.net [73.78.137.212]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by complete.lackof.org (Postfix) with ESMTPSA id 1366933E0046 for ; Thu, 3 May 2018 14:06:41 -0600 (MDT) From: dann frazier To: kernel-team@lists.ubuntu.com Subject: [PATCH][SRU Bionic] ata: do not schedule hot plug if it is a sas host Date: Thu, 3 May 2018 14:06:35 -0600 Message-Id: <20180503200635.13988-1-dann.frazier@canonical.com> X-Mailer: git-send-email 2.17.0 X-Virus-Scanned: clamav-milter 0.99.4 at complete.lackof.org X-Virus-Status: Clean X-Spam-Status: No, score=0.3 required=5.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, UNPARSEABLE_RELAY autolearn=no autolearn_force=no version=3.4.1 X-Spam-Checker-Version: SpamAssassin 3.4.1 (2015-04-28) on complete.lackof.org X-BeenThere: kernel-team@lists.ubuntu.com X-Mailman-Version: 2.1.20 Precedence: list List-Id: Kernel team discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Errors-To: kernel-team-bounces@lists.ubuntu.com Sender: "kernel-team" From: Jason Yan BugLink: https://bugs.launchpad.net/bugs/1768948 We've got a kernel panic when using sata disk with sas controller: [115946.152283] Unable to handle kernel NULL pointer dereference at virtual address 000007d8 [115946.223963] CPU: 0 PID: 22175 Comm: kworker/0:1 Tainted: G W OEL 4.14.0 #1 [115946.232925] Workqueue: events ata_scsi_hotplug [115946.237938] task: ffff8021ee50b180 task.stack: ffff00000d5d0000 [115946.244717] PC is at sas_find_dev_by_rphy+0x44/0x114 [115946.250224] LR is at sas_find_dev_by_rphy+0x3c/0x114 ...... [115946.355701] Process kworker/0:1 (pid: 22175, stack limit = 0xffff00000d5d0000) [115946.363369] Call trace: [115946.456356] [] sas_find_dev_by_rphy+0x44/0x114 [115946.462908] [] sas_target_alloc+0x20/0x5c [115946.469408] [] scsi_alloc_target+0x250/0x308 [115946.475781] [] __scsi_add_device+0xb0/0x154 [115946.481991] [] ata_scsi_scan_host+0x180/0x218 [115946.488367] [] ata_scsi_hotplug+0xb0/0xcc [115946.494801] [] process_one_work+0x144/0x390 [115946.501115] [] worker_thread+0x144/0x418 [115946.507093] [] kthread+0x10c/0x138 [115946.512792] [] ret_from_fork+0x10/0x18 We found that Ding Xiang has reported a similar bug before: https://patchwork.kernel.org/patch/9179817/ And this bug still exists in mainline. Since libsas handles hotplug and device adding/removing itself, do not need to schedule ata hot plug task here if it is a sas host. Signed-off-by: Jason Yan Cc: Ding Xiang Cc: stable@vger.kernel.org Signed-off-by: Tejun Heo (cherry picked from commit 6f54120e17e311fd7ac42b9ec2a0611caa5b46ad) Signed-off-by: dann frazier Acked-by: Kleber Sacilotto de Souza Acked-by: Stefan Bader --- drivers/ata/libata-eh.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/ata/libata-eh.c b/drivers/ata/libata-eh.c index 11c3137d7b0a..c016829a38fd 100644 --- a/drivers/ata/libata-eh.c +++ b/drivers/ata/libata-eh.c @@ -815,7 +815,8 @@ void ata_scsi_port_error_handler(struct Scsi_Host *host, struct ata_port *ap) if (ap->pflags & ATA_PFLAG_LOADING) ap->pflags &= ~ATA_PFLAG_LOADING; - else if (ap->pflags & ATA_PFLAG_SCSI_HOTPLUG) + else if ((ap->pflags & ATA_PFLAG_SCSI_HOTPLUG) && + !(ap->flags & ATA_FLAG_SAS_HOST)) schedule_delayed_work(&ap->hotplug_task, 0); if (ap->pflags & ATA_PFLAG_RECOVERED)