On 2012-9-19 10:40, Yijing Wang wrote:
> 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 | 27 ++++++++++++++++++++++++++-
> 1 files changed, 26 insertions(+), 1 deletions(-)
>
> diff --git a/drivers/pci/pcie/aer/aer_inject.c b/drivers/pci/pcie/aer/aer_inject.c
> index 4e24cb8..0f00a27 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 upstream 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);
How about move BUG_ON(!ops)into __find_pci_bus_ops?
> spin_unlock_irqrestore(&inject_lock, flags);
> return ops->write(bus, devfn, where, size, val);
> }
> @@ -506,6 +530,7 @@ static struct miscdevice aer_inject_device = {
> .fops = &aer_inject_fops,
> };
>
> +
Please remove this above line.
> static int __init aer_inject_init(void)
> {
> return misc_register(&aer_inject_device);
--
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