From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from szxga01-in.huawei.com ([119.145.14.64]:7099 "EHLO szxga01-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754020Ab2IUDqV (ORCPT ); Thu, 20 Sep 2012 23:46:21 -0400 From: Yijing Wang To: Bjorn Helgaas , Huang Ying , Chen Gong CC: , Hanjun Guo , , Yijing Wang Subject: [PATCH v4 1/5] PCI/AER: Fix pci_ops return NULL in pci_read/write_aer Date: Fri, 21 Sep 2012 11:44:12 +0800 Message-ID: <1348199056-7696-2-git-send-email-wangyijing@huawei.com> In-Reply-To: <1348199056-7696-1-git-send-email-wangyijing@huawei.com> References: <1348199056-7696-1-git-send-email-wangyijing@huawei.com> MIME-Version: 1.0 Content-Type: text/plain Sender: linux-pci-owner@vger.kernel.org List-ID: 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 --- 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); } -- 1.7.1