On 2012/9/21 13:08, Huang Ying wrote:
> On Fri, 2012-09-21 at 11:44 +0800, Yijing Wang wrote:
>> When we rmmod aer_inject module, there is a small race condition window between pci_bus_ops_pop()
>> and pci_bus_set_ops() in aer_inject_exit, eg. pci_read_aer/pci_write_aer was called between
>> them. So introduce pci_bus_ops_get() to avoid this.
>>
>> Signed-off-by: Yijing Wang <wangyijing@xxxxxxxxxx>
>> Signed-off-by: Huang Ying <ying.huang@xxxxxxxxx>
>
> Please don't add my signed-off.
>
>> ---
>> drivers/pci/pcie/aer/aer_inject.c | 21 ++++++++++++++++++---
>> 1 files changed, 18 insertions(+), 3 deletions(-)
>>
>> diff --git a/drivers/pci/pcie/aer/aer_inject.c b/drivers/pci/pcie/aer/aer_inject.c
>> index fdab3bb..0123120 100644
>> --- a/drivers/pci/pcie/aer/aer_inject.c
>> +++ b/drivers/pci/pcie/aer/aer_inject.c
>> @@ -67,6 +67,8 @@ struct pci_bus_ops {
>> struct pci_ops *ops;
>> };
>>
>> +#define to_pci_bus_ops(n) container_of(n, struct pci_bus_ops, list)
>> +
>> static LIST_HEAD(einjected);
>>
>> static LIST_HEAD(pci_bus_ops_list);
>> @@ -160,6 +162,18 @@ static struct pci_bus_ops *pci_bus_ops_pop(void)
>> return bus_ops;
>> }
>>
>> +static struct pci_bus_ops *pci_bus_ops_get(struct pci_bus_ops *from)
>> +{
>> + struct pci_bus_ops *bus_ops = NULL;
>> + struct list_head *n;
>> +
>> + n = from ? from->list.next : pci_bus_ops_list.next;
>> + if (n != &pci_bus_ops_list)
>> + bus_ops = to_pci_bus_ops(n);
>> +
>> + return bus_ops;
>> +}
>> +
>> static u32 *find_pci_config_dword(struct aer_error *err, int where,
>> int *prw1cs)
>> {
>> @@ -539,14 +553,15 @@ static void __exit aer_inject_exit(void)
>> {
>> struct aer_error *err, *err_next;
>> unsigned long flags;
>> - struct pci_bus_ops *bus_ops;
>> + struct pci_bus_ops *bus_ops = NULL;
>>
>> misc_deregister(&aer_inject_device);
>>
>> - while ((bus_ops = pci_bus_ops_pop())) {
>> + while ((bus_ops = pci_bus_ops_get(bus_ops)))
>> pci_bus_set_ops(bus_ops->bus, bus_ops->ops);
>
> Why not just use
>
> list_for_each_entry(&pci_bus_ops_list) {
> pci_bus_set_ops();
> }
>
Yes, you are right, use list_for_each_entry(&pci_bus_ops_list) is cleaner.
Thanks
Yijing
> Best Regards,
> Huang Ying
>
>> +
>> + while ((bus_ops = pci_bus_ops_pop()))
>> kfree(bus_ops);
>> - }
>>
>> spin_lock_irqsave(&inject_lock, flags);
>> list_for_each_entry_safe(err, err_next, &einjected, list) {
>
>
>
> .
>
--
Thanks!
Yijing
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