lkml.org 
[lkml]   [2012]   [Aug]   [27]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [RESEND BUGFIX PATCH 1/3] PCI/AER: fix pci_ops return NULL when hotplug a pci bus which was doing aer error inject
>> bash[5908]: NaT consumption 17179869216 [1]
>> Modules linked in: aer_inject cpufreq_conservative cpufreq_userspace cpufreq_pow
>> ersave acpi_cpufreq binfmt_misc fuse nls_iso8859_1 loop ipmi_si(+) ipmi_devintf
>> ipmi_msghandler dm_mod ppdev iTCO_wdt iTCO_vendor_support sg igb parport_pc i2c_
>> i801 mptctl i2c_core serio_raw hid_generic lpc_ich mfd_core parport button conta
>> iner usbhid hid uhci_hcd ehci_hcd usbcore usb_common sd_mod crc_t10dif ext3 mbca
>> che jbd fan processor ide_pci_generic ide_core ata_piix libata mptsas mptscsih m
>> ptbase scsi_transport_sas scsi_mod thermal thermal_sys hwmon
>>
> [...]
>>
>> Signed-off-by: Yijing Wang <wangyijing@huawei.com>
>> Signed-off-by: Jiang Liu <liuj97@gmail.com>
>> ---
>> drivers/pci/pcie/aer/aer_inject.c | 21 +++++++++++++++++++++
>> 1 files changed, 21 insertions(+), 0 deletions(-)
>>
>> diff --git a/drivers/pci/pcie/aer/aer_inject.c b/drivers/pci/pcie/aer/aer_inject.c
>> index 5222986..fc28785 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;
>> }
>> +
>> + /* here 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;
>> }
>>
> At least, when returning NULL, a proper check and protection is needed.
>
Hi Chen Gong,
Thanks for your comments. It's real dangerous when returning NULL, Since pci_read_aer/pci_write_aer functions
had no any protection codes to check it. I think maybe we can treat this situation as a read/write access error, and set *val = 0 ?
Another way here is panic system, Becasue this is a really unexpected situation.

--
Thanks!
Yijing



\
 
 \ /
  Last update: 2012-08-28 03:21    [W:1.152 / U:0.040 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site