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=-6.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable 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 D49C4C352BE for ; Thu, 16 Apr 2020 14:49:46 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B3F6C2223D for ; Thu, 16 Apr 2020 14:49:46 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1587048586; bh=BSa93prsmqtl3l+Nd2NXht7SlPxTZO8IC0eMwwLaAMk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=a9ZlrS/wji9HMvklkFaHuN8zAuur2nQVQZUgqTT6huDBObIS+U81G18WWbeeCNnZz Xzsvm4MfMA/8gKuwQXaRQ+2EmfwapWcCFNNbXajasMt/3YQfEaq4svLFfCull7EJHd PcXNW5QVZn/zXx27g17U4FPEyuJVasHFzehUOc/I= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2391920AbgDPOtm (ORCPT ); Thu, 16 Apr 2020 10:49:42 -0400 Received: from mail.kernel.org ([198.145.29.99]:45586 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2409375AbgDPN6g (ORCPT ); Thu, 16 Apr 2020 09:58:36 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id EB2A520786; Thu, 16 Apr 2020 13:58:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1587045515; bh=BSa93prsmqtl3l+Nd2NXht7SlPxTZO8IC0eMwwLaAMk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=LsDgMuynCQ+Wgz8u9hZJ5aZdbfN7nk58kr85OHtWZszh7NcvjYkwxQsYpDkdzk3wf ZheaAQNmPLHelBVPLfXVTE0NQO+NRxBvM6bYLFL0k3JS17jB0ZPJpgW92K95+uszPL j9mCk0jnIoiKM3grqvhpK+++e/VpguI3cZ5oHaQg= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Sreekanth Reddy , "Martin K. Petersen" , Guenter Roeck Subject: [PATCH 5.6 166/254] scsi: mpt3sas: Fix kernel panic observed on soft HBA unplug Date: Thu, 16 Apr 2020 15:24:15 +0200 Message-Id: <20200416131347.298335124@linuxfoundation.org> X-Mailer: git-send-email 2.26.1 In-Reply-To: <20200416131325.804095985@linuxfoundation.org> References: <20200416131325.804095985@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Sreekanth Reddy commit cc41f11a21a51d6869d71e525a7264c748d7c0d7 upstream. Generic protection fault type kernel panic is observed when user performs soft (ordered) HBA unplug operation while IOs are running on drives connected to HBA. When user performs ordered HBA removal operation, the kernel calls PCI device's .remove() call back function where driver is flushing out all the outstanding SCSI IO commands with DID_NO_CONNECT host byte and also unmaps sg buffers allocated for these IO commands. However, in the ordered HBA removal case (unlike of real HBA hot removal), HBA device is still alive and hence HBA hardware is performing the DMA operations to those buffers on the system memory which are already unmapped while flushing out the outstanding SCSI IO commands and this leads to kernel panic. Don't flush out the outstanding IOs from .remove() path in case of ordered removal since HBA will be still alive in this case and it can complete the outstanding IOs. Flush out the outstanding IOs only in case of 'physical HBA hot unplug' where there won't be any communication with the HBA. During shutdown also it is possible that HBA hardware can perform DMA operations on those outstanding IO buffers which are completed with DID_NO_CONNECT by the driver from .shutdown(). So same above fix is applied in shutdown path as well. It is safe to drop the outstanding commands when HBA is inaccessible such as when permanent PCI failure happens, when HBA is in non-operational state, or when someone does a real HBA hot unplug operation. Since driver knows that HBA is inaccessible during these cases, it is safe to drop the outstanding commands instead of waiting for SCSI error recovery to kick in and clear these outstanding commands. Link: https://lore.kernel.org/r/1585302763-23007-1-git-send-email-sreekanth.reddy@broadcom.com Fixes: c666d3be99c0 ("scsi: mpt3sas: wait for and flush running commands on shutdown/unload") Cc: stable@vger.kernel.org #v4.14.174+ Signed-off-by: Sreekanth Reddy Signed-off-by: Martin K. Petersen Cc: Guenter Roeck Signed-off-by: Greg Kroah-Hartman --- drivers/scsi/mpt3sas/mpt3sas_scsih.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) --- a/drivers/scsi/mpt3sas/mpt3sas_scsih.c +++ b/drivers/scsi/mpt3sas/mpt3sas_scsih.c @@ -9908,8 +9908,8 @@ static void scsih_remove(struct pci_dev ioc->remove_host = 1; - mpt3sas_wait_for_commands_to_complete(ioc); - _scsih_flush_running_cmds(ioc); + if (!pci_device_is_present(pdev)) + _scsih_flush_running_cmds(ioc); _scsih_fw_event_cleanup_queue(ioc); @@ -9992,8 +9992,8 @@ scsih_shutdown(struct pci_dev *pdev) ioc->remove_host = 1; - mpt3sas_wait_for_commands_to_complete(ioc); - _scsih_flush_running_cmds(ioc); + if (!pci_device_is_present(pdev)) + _scsih_flush_running_cmds(ioc); _scsih_fw_event_cleanup_queue(ioc);