From patchwork Fri Aug 2 06:32:47 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sam Bobroff X-Patchwork-Id: 1140976 Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Received: from lists.ozlabs.org (lists.ozlabs.org [IPv6:2401:3900:2:1::3]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 460HSc0fWHz9s3Z for ; Fri, 2 Aug 2019 16:34:24 +1000 (AEST) Authentication-Results: ozlabs.org; dmarc=none (p=none dis=none) header.from=linux.ibm.com Received: from lists.ozlabs.org (lists.ozlabs.org [IPv6:2401:3900:2:1::3]) by lists.ozlabs.org (Postfix) with ESMTP id 460HSb6m6GzDqwN for ; Fri, 2 Aug 2019 16:34:23 +1000 (AEST) X-Original-To: linuxppc-dev@lists.ozlabs.org Delivered-To: linuxppc-dev@lists.ozlabs.org Authentication-Results: lists.ozlabs.org; spf=pass (mailfrom) smtp.mailfrom=linux.ibm.com (client-ip=148.163.156.1; helo=mx0a-001b2d01.pphosted.com; envelope-from=sbobroff@linux.ibm.com; receiver=) Authentication-Results: lists.ozlabs.org; dmarc=none (p=none dis=none) header.from=linux.ibm.com Received: from mx0a-001b2d01.pphosted.com (mx0a-001b2d01.pphosted.com [148.163.156.1]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 460HQx2bS6zDqnM for ; Fri, 2 Aug 2019 16:32:56 +1000 (AEST) Received: from pps.filterd (m0098399.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.27/8.16.0.27) with SMTP id x726O1HL117473 for ; Fri, 2 Aug 2019 02:32:54 -0400 Received: from e06smtp05.uk.ibm.com (e06smtp05.uk.ibm.com [195.75.94.101]) by mx0a-001b2d01.pphosted.com with ESMTP id 2u4csfwye8-1 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NOT) for ; Fri, 02 Aug 2019 02:32:54 -0400 Received: from localhost by e06smtp05.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! 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Violators will be prosecuted; (version=TLSv1/SSLv3 cipher=AES256-GCM-SHA384 bits=256/256) Fri, 2 Aug 2019 07:32:50 +0100 Received: from d06av22.portsmouth.uk.ibm.com (d06av22.portsmouth.uk.ibm.com [9.149.105.58]) by b06cxnps4075.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id x726Wn3w56819912 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK) for ; Fri, 2 Aug 2019 06:32:49 GMT Received: from d06av22.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 41AAA4C04E for ; Fri, 2 Aug 2019 06:32:49 +0000 (GMT) Received: from d06av22.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 9D6334C050 for ; Fri, 2 Aug 2019 06:32:48 +0000 (GMT) Received: from ozlabs.au.ibm.com (unknown [9.192.253.14]) by d06av22.portsmouth.uk.ibm.com (Postfix) with ESMTP for ; Fri, 2 Aug 2019 06:32:48 +0000 (GMT) Received: from tungsten.ozlabs.ibm.com (haven.au.ibm.com [9.192.254.114]) (using TLSv1.2 with cipher DHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by ozlabs.au.ibm.com (Postfix) with ESMTPSA id A259FA0399 for ; Fri, 2 Aug 2019 16:32:47 +1000 (AEST) From: Sam Bobroff To: linuxppc-dev@lists.ozlabs.org Subject: [PATCH 3/3] powerpc/eeh: Fix crash when edev->pdev changes Date: Fri, 2 Aug 2019 16:32:47 +1000 X-Mailer: git-send-email 2.22.0.216.g00a2a96fc9 In-Reply-To: References: MIME-Version: 1.0 X-TM-AS-GCONF: 00 x-cbid: 19080206-0020-0000-0000-00000359A144 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 19080206-0021-0000-0000-000021ADB3F7 Message-Id: <5f5e86314b832b518bc1aacddcf7494e0818580b.1564727543.git.sbobroff@linux.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:, , definitions=2019-08-02_04:, , signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 priorityscore=1501 malwarescore=0 suspectscore=1 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=8.0.1-1906280000 definitions=main-1908020067 X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: linuxppc-dev-bounces+patchwork-incoming=ozlabs.org@lists.ozlabs.org Sender: "Linuxppc-dev" If a PCI device is removed during eeh_pe_report_edev(), between the calls to device_lock() and device_unlock(), edev->pdev will change and cause a crash as the wrong mutex is released. To correct this, hold the PCI rescan/remove lock while taking a copy of edev->pdev and performing a get_device() on it. Use this value to release the mutex, but also pass it through to the device driver's EEH handlers so that they always see the same device. Signed-off-by: Sam Bobroff --- arch/powerpc/kernel/eeh_driver.c | 44 +++++++++++++++++++++----------- 1 file changed, 29 insertions(+), 15 deletions(-) diff --git a/arch/powerpc/kernel/eeh_driver.c b/arch/powerpc/kernel/eeh_driver.c index 927b59d8a9e5..56841c6451e5 100644 --- a/arch/powerpc/kernel/eeh_driver.c +++ b/arch/powerpc/kernel/eeh_driver.c @@ -257,20 +257,27 @@ static void eeh_set_irq_state(struct eeh_pe *root, bool enable) } typedef enum pci_ers_result (*eeh_report_fn)(struct eeh_dev *, + struct pci_dev *, struct pci_driver *); static void eeh_pe_report_edev(struct eeh_dev *edev, eeh_report_fn fn, enum pci_ers_result *result) { + struct pci_dev *pdev; struct pci_driver *driver; enum pci_ers_result new_result; - if (!edev->pdev) { + pci_lock_rescan_remove(); + pdev = edev->pdev; + if (pdev) + get_device(&pdev->dev); + pci_unlock_rescan_remove(); + if (!pdev) { eeh_edev_info(edev, "no device"); return; } - device_lock(&edev->pdev->dev); + device_lock(&pdev->dev); if (eeh_edev_actionable(edev)) { - driver = eeh_pcid_get(edev->pdev); + driver = eeh_pcid_get(pdev); if (!driver) eeh_edev_info(edev, "no driver"); @@ -279,7 +286,7 @@ static void eeh_pe_report_edev(struct eeh_dev *edev, eeh_report_fn fn, else if (edev->mode & EEH_DEV_NO_HANDLER) eeh_edev_info(edev, "driver bound too late"); else { - new_result = fn(edev, driver); + new_result = fn(edev, pdev, driver); eeh_edev_info(edev, "%s driver reports: '%s'", driver->name, pci_ers_result_name(new_result)); @@ -288,12 +295,15 @@ static void eeh_pe_report_edev(struct eeh_dev *edev, eeh_report_fn fn, new_result); } if (driver) - eeh_pcid_put(edev->pdev); + eeh_pcid_put(pdev); } else { - eeh_edev_info(edev, "not actionable (%d,%d,%d)", !!edev->pdev, + eeh_edev_info(edev, "not actionable (%d,%d,%d)", !!pdev, !eeh_dev_removed(edev), !eeh_pe_passed(edev->pe)); } - device_unlock(&edev->pdev->dev); + device_unlock(&pdev->dev); + if (edev->pdev != pdev) + eeh_edev_warn(edev, "Device changed during processing!\n"); + put_device(&pdev->dev); } static void eeh_pe_report(const char *name, struct eeh_pe *root, @@ -320,20 +330,20 @@ static void eeh_pe_report(const char *name, struct eeh_pe *root, * Report an EEH error to each device driver. */ static enum pci_ers_result eeh_report_error(struct eeh_dev *edev, + struct pci_dev *pdev, struct pci_driver *driver) { enum pci_ers_result rc; - struct pci_dev *dev = edev->pdev; if (!driver->err_handler->error_detected) return PCI_ERS_RESULT_NONE; eeh_edev_info(edev, "Invoking %s->error_detected(IO frozen)", driver->name); - rc = driver->err_handler->error_detected(dev, pci_channel_io_frozen); + rc = driver->err_handler->error_detected(pdev, pci_channel_io_frozen); edev->in_error = true; - pci_uevent_ers(dev, PCI_ERS_RESULT_NONE); + pci_uevent_ers(pdev, PCI_ERS_RESULT_NONE); return rc; } @@ -346,12 +356,13 @@ static enum pci_ers_result eeh_report_error(struct eeh_dev *edev, * are now enabled. */ static enum pci_ers_result eeh_report_mmio_enabled(struct eeh_dev *edev, + struct pci_dev *pdev, struct pci_driver *driver) { if (!driver->err_handler->mmio_enabled) return PCI_ERS_RESULT_NONE; eeh_edev_info(edev, "Invoking %s->mmio_enabled()", driver->name); - return driver->err_handler->mmio_enabled(edev->pdev); + return driver->err_handler->mmio_enabled(pdev); } /** @@ -365,12 +376,13 @@ static enum pci_ers_result eeh_report_mmio_enabled(struct eeh_dev *edev, * driver can work again while the device is recovered. */ static enum pci_ers_result eeh_report_reset(struct eeh_dev *edev, + struct pci_dev *pdev, struct pci_driver *driver) { if (!driver->err_handler->slot_reset || !edev->in_error) return PCI_ERS_RESULT_NONE; eeh_edev_info(edev, "Invoking %s->slot_reset()", driver->name); - return driver->err_handler->slot_reset(edev->pdev); + return driver->err_handler->slot_reset(pdev); } static void eeh_dev_restore_state(struct eeh_dev *edev, void *userdata) @@ -410,13 +422,14 @@ static void eeh_dev_restore_state(struct eeh_dev *edev, void *userdata) * to make the recovered device work again. */ static enum pci_ers_result eeh_report_resume(struct eeh_dev *edev, + struct pci_dev *pdev, struct pci_driver *driver) { if (!driver->err_handler->resume || !edev->in_error) return PCI_ERS_RESULT_NONE; eeh_edev_info(edev, "Invoking %s->resume()", driver->name); - driver->err_handler->resume(edev->pdev); + driver->err_handler->resume(pdev); pci_uevent_ers(edev->pdev, PCI_ERS_RESULT_RECOVERED); #ifdef CONFIG_PCI_IOV @@ -435,6 +448,7 @@ static enum pci_ers_result eeh_report_resume(struct eeh_dev *edev, * dead, and that no further recovery attempts will be made on it. */ static enum pci_ers_result eeh_report_failure(struct eeh_dev *edev, + struct pci_dev *pdev, struct pci_driver *driver) { enum pci_ers_result rc; @@ -444,10 +458,10 @@ static enum pci_ers_result eeh_report_failure(struct eeh_dev *edev, eeh_edev_info(edev, "Invoking %s->error_detected(permanent failure)", driver->name); - rc = driver->err_handler->error_detected(edev->pdev, + rc = driver->err_handler->error_detected(pdev, pci_channel_io_perm_failure); - pci_uevent_ers(edev->pdev, PCI_ERS_RESULT_DISCONNECT); + pci_uevent_ers(pdev, PCI_ERS_RESULT_DISCONNECT); return rc; }