From patchwork Fri Sep 21 08:43:09 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Yijing Wang X-Patchwork-Id: 185614 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 140E72C007C for ; Fri, 21 Sep 2012 18:44:36 +1000 (EST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756965Ab2IUIof (ORCPT ); Fri, 21 Sep 2012 04:44:35 -0400 Received: from szxga02-in.huawei.com ([119.145.14.65]:16400 "EHLO szxga02-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756701Ab2IUIoe (ORCPT ); Fri, 21 Sep 2012 04:44:34 -0400 Received: from 172.24.2.119 (EHLO szxeml205-edg.china.huawei.com) ([172.24.2.119]) by szxrg02-dlp.huawei.com (MOS 4.3.4-GA FastPath queued) with ESMTP id APK38175; Fri, 21 Sep 2012 16:44:29 +0800 (CST) Received: from SZXEML410-HUB.china.huawei.com (10.82.67.137) by szxeml205-edg.china.huawei.com (172.24.2.58) with Microsoft SMTP Server (TLS) id 14.1.323.3; Fri, 21 Sep 2012 16:43:48 +0800 Received: from localhost (10.135.76.84) by szxeml410-hub.china.huawei.com (10.82.67.137) with Microsoft SMTP Server id 14.1.323.3; Fri, 21 Sep 2012 16:43:45 +0800 From: Yijing Wang To: Bjorn Helgaas , Huang Ying , Chen Gong CC: , Hanjun Guo , , Yijing Wang Subject: [PATCH v5 1/5] PCI/AER: Fix pci_ops return NULL in pci_read/write_aer Date: Fri, 21 Sep 2012 16:43:09 +0800 Message-ID: <1348216993-6948-2-git-send-email-wangyijing@huawei.com> X-Mailer: git-send-email 1.7.11.msysgit.1 In-Reply-To: <1348216993-6948-1-git-send-email-wangyijing@huawei.com> References: <1348216993-6948-1-git-send-email-wangyijing@huawei.com> MIME-Version: 1.0 X-Originating-IP: [10.135.76.84] X-CFilter-Loop: Reflected Sender: linux-pci-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org When we injected aer errors to the pcie device by aer_inject module, pci_ops of the pci bus the device on will be assigned to pci_ops_aer.So if the target pci device is a bridge, once we hot-remove and hot-add the bridge, the newly created child bus's pci_ops will be assigned to pci_ops_aer too.Now every access to the child bus's device will cause the system panic, because it will get a NULL pci_ops in pci_read_aer/pci_write_aer. Signed-off-by: Yijing Wang Signed-off-by: Jiang Liu Reviewed-by: Sven Dietrich Reviewed-by: Huang Ying --- drivers/pci/pcie/aer/aer_inject.c | 26 +++++++++++++++++++++++++- 1 files changed, 25 insertions(+), 1 deletions(-) diff --git a/drivers/pci/pcie/aer/aer_inject.c b/drivers/pci/pcie/aer/aer_inject.c index 4e24cb8..fdab3bb 100644 --- a/drivers/pci/pcie/aer/aer_inject.c +++ b/drivers/pci/pcie/aer/aer_inject.c @@ -109,6 +109,26 @@ static struct aer_error *__find_aer_error_by_dev(struct pci_dev *dev) return __find_aer_error((u16)domain, dev->bus->number, dev->devfn); } +/* find pci_ops of the nearest parent bus */ +static struct pci_ops *__find_pci_bus_ops_parent(struct pci_bus *bus) +{ + struct pci_bus_ops *bus_ops; + struct pci_bus *pbus = bus->parent; + + if (!pbus) + return NULL; + + while (pbus) { + list_for_each_entry(bus_ops, &pci_bus_ops_list, list) + if (bus_ops->bus == pbus) + return bus_ops->ops; + + pbus = pbus->parent; + } + + return NULL; +} + /* inject_lock must be held before calling */ static struct pci_ops *__find_pci_bus_ops(struct pci_bus *bus) { @@ -118,7 +138,9 @@ static struct pci_ops *__find_pci_bus_ops(struct pci_bus *bus) if (bus_ops->bus == bus) return bus_ops->ops; } - return NULL; + + /* can't find bus_ops, fall back to get bus_ops of parent bus */ + return __find_pci_bus_ops_parent(bus); } static struct pci_bus_ops *pci_bus_ops_pop(void) @@ -208,6 +230,7 @@ static int pci_read_aer(struct pci_bus *bus, unsigned int devfn, int where, } out: ops = __find_pci_bus_ops(bus); + BUG_ON(!ops); spin_unlock_irqrestore(&inject_lock, flags); return ops->read(bus, devfn, where, size, val); } @@ -243,6 +266,7 @@ int pci_write_aer(struct pci_bus *bus, unsigned int devfn, int where, int size, } out: ops = __find_pci_bus_ops(bus); + BUG_ON(!ops); spin_unlock_irqrestore(&inject_lock, flags); return ops->write(bus, devfn, where, size, val); }