From: Yijing Wang <wangyijing@huawei.com>
To: Bjorn Helgaas <bhelgaas@google.com>,
Rusty Russell <rusty@rustcorp.com.au>,
Mauro Carvalho Chehab <mchehab@redhat.com>,
PCI <linux-pci@vger.kernel.org>, Jiang Liu <liuj97@gmail.com>,
Huang Ying <ying.huang@intel.com>,
Hanjun Guo <guohanjun@huawei.com>, <linux-kernel@vger.kernel.org>,
<gong.chen@linux.intel.com>
Subject: Re: [RESEND BUGFIX PATCH 1/3] PCI/AER: fix pci_ops return NULL when hotplug a pci bus which was doing aer error inject
Date: Tue, 28 Aug 2012 08:47:31 +0800 [thread overview]
Message-ID: <503C1523.30302@huawei.com> (raw)
In-Reply-To: <20120827084924.GB3858@gchen.bj.intel.com>
>> 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
prev parent reply other threads:[~2012-08-28 0:49 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-08-11 11:52 [PATCH 1/3] PCI/AER: Fix NULL pci_ops return when hotplug a pci bus which was doing aer error inject Yijing Wang
2012-08-11 11:52 ` [PATCH 2/3] PCI/AER: Clean pci_bus_ops when related pci bus was removed Yijing Wang
2012-08-25 9:59 ` [RESEND BUGFIX PATCH 2/3] PCI/AER: clean " Yijing Wang
2012-08-11 11:52 ` [PATCH 3/3] PCI: Check whether pci device has been removed when remove a pci device by sysfs Yijing Wang
2012-08-25 9:59 ` [RESEND BUGFIX PATCH 3/3] PCI: check " Yijing Wang
2012-08-25 14:39 ` Jiang Liu
2012-08-27 6:42 ` Yijing Wang
2012-08-25 9:59 ` [RESEND BUGFIX PATCH 1/3] PCI/AER: fix pci_ops return NULL when hotplug a pci bus which was doing aer error inject Yijing Wang
2012-08-27 1:23 ` Huang Ying
2012-08-27 15:05 ` Jiang Liu
2012-08-28 0:38 ` Huang Ying
2012-08-28 0:53 ` Yijing Wang
2012-08-27 8:49 ` Chen Gong
2012-08-28 0:47 ` Yijing Wang [this message]
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