When we inject aer errors to the target pcie device by aer_inject module, the pci_ops of pci bus which the target device is 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 devices will result to system panic, because it get a NULL pci_ops in pci_read_aer/pci_write_aer. Signed-off-by: Yijing Wang <wangyijing@xxxxxxxxxx> Signed-off-by: Jiang Liu <jiang.liu@xxxxxxxxxx> Reviewed-by: Sven Dietrich <Sven.Dietrich@xxxxxxxxxx> --- drivers/pci/pcie/aer/aer_inject.c | 23 +++++++++++++++++++++++ 1 files changed, 23 insertions(+), 0 deletions(-) diff --git a/drivers/pci/pcie/aer/aer_inject.c b/drivers/pci/pcie/aer/aer_inject.c index 4e24cb8..0816483 100644 --- a/drivers/pci/pcie/aer/aer_inject.c +++ b/drivers/pci/pcie/aer/aer_inject.c @@ -109,6 +109,19 @@ static struct aer_error *__find_aer_error_by_dev(struct pci_dev *dev) return __find_aer_error((u16)domain, dev->bus->number, dev->devfn); } +static bool pci_is_upstream_bus(struct pci_bus *bus, struct pci_bus *up_bus) +{ + struct pci_bus *pbus = bus->parent; + + while (pbus) { + if (pbus == up_bus) + return true; + pbus = pbus->parent; + } + + return false; +} + /* inject_lock must be held before calling */ static struct pci_ops *__find_pci_bus_ops(struct pci_bus *bus) { @@ -118,6 +131,13 @@ static struct pci_ops *__find_pci_bus_ops(struct pci_bus *bus) if (bus_ops->bus == bus) return bus_ops->ops; } + + /* can't find bus_ops, fall back to get bus_ops of upstream bus */ + list_for_each_entry(bus_ops, &pci_bus_ops_list, list) { + if (pci_is_upstream_bus(bus, bus_ops->bus)) + return bus_ops->ops; + } + return NULL; } @@ -208,6 +228,7 @@ 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 +264,7 @@ 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); } @@ -506,6 +528,7 @@ static struct miscdevice aer_inject_device = { .fops = &aer_inject_fops, }; + static int __init aer_inject_init(void) { return misc_register(&aer_inject_device); -- 1.7.1 -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html