From: poza@codeaurora.org
To: Thomas Tai <thomas.tai@oracle.com>
Cc: bhelgaas@google.com, keith.busch@intel.com,
linux-pci@vger.kernel.org, linux-pci-owner@vger.kernel.org
Subject: Re: [PATCH 1/1] PCI/AER: prevent pcie_do_fatal_recovery from using device after it is removed
Date: Tue, 14 Aug 2018 14:52:29 +0530 [thread overview]
Message-ID: <b0104a716319d76e734c307cb4bedd9d@codeaurora.org> (raw)
In-Reply-To: <51f4b387d9bd96a42d526a6a029fc43b@codeaurora.org>
On 2018-08-14 14:46, poza@codeaurora.org wrote:
> On 2018-08-13 22:21, Thomas Tai wrote:
>> In order to prevent the pcie_do_fatal_recovery() from
>> using the device after it is removed, the device's
>> domain:bus:devfn is stored at the entry of
>> pcie_do_fatal_recovery(). After rescanning the bus, the
>> stored domain:bus:devfn is used to find the device and
>> uses to report pci_info. The original issue only happens
>> on an non-bridge device, a local variable is used instead
>> of checking the device's header type.
>>
>> Signed-off-by: Thomas Tai <thomas.tai@oracle.com>
>> ---
>> drivers/pci/pcie/err.c | 33 +++++++++++++++++++++++----------
>> 1 file changed, 23 insertions(+), 10 deletions(-)
>>
>> diff --git a/drivers/pci/pcie/err.c b/drivers/pci/pcie/err.c
>> index f02e334..3414445 100644
>> --- a/drivers/pci/pcie/err.c
>> +++ b/drivers/pci/pcie/err.c
>> @@ -287,15 +287,20 @@ void pcie_do_fatal_recovery(struct pci_dev *dev,
>> u32 service)
>> struct pci_bus *parent;
>> struct pci_dev *pdev, *temp;
>> pci_ers_result_t result;
>> + bool is_bridge_device = false;
>> + u16 domain = pci_domain_nr(dev->bus);
>> + u8 bus = dev->bus->number;
>> + u8 devfn = dev->devfn;
>>
>> - if (dev->hdr_type == PCI_HEADER_TYPE_BRIDGE)
>> + if (dev->hdr_type == PCI_HEADER_TYPE_BRIDGE) {
>> + is_bridge_device = true;
>> udev = dev;
>> - else
>> + } else {
>> udev = dev->bus->self;
>> + }
>>
>> parent = udev->subordinate;
>> pci_lock_rescan_remove();
>> - pci_dev_get(dev);
>> list_for_each_entry_safe_reverse(pdev, temp, &parent->devices,
>> bus_list) {
>> pci_dev_get(pdev);
>> @@ -309,27 +314,35 @@ void pcie_do_fatal_recovery(struct pci_dev *dev,
>> u32 service)
>>
>> result = reset_link(udev, service);
>>
>> - if ((service == PCIE_PORT_SERVICE_AER) &&
>> - (dev->hdr_type == PCI_HEADER_TYPE_BRIDGE)) {
>> + if (service == PCIE_PORT_SERVICE_AER && is_bridge_device) {
>> /*
>> * If the error is reported by a bridge, we think this error
>> * is related to the downstream link of the bridge, so we
>> * do error recovery on all subordinates of the bridge instead
>> * of the bridge and clear the error status of the bridge.
>> */
>> - pci_cleanup_aer_uncorrect_error_status(dev);
>> + pci_cleanup_aer_uncorrect_error_status(udev);
>> }
>>
>> if (result == PCI_ERS_RESULT_RECOVERED) {
>> if (pcie_wait_for_link(udev, true))
>> pci_rescan_bus(udev->bus);
>> - pci_info(dev, "Device recovery from fatal error successful\n");
>> + /* find the pci_dev after rescanning the bus */
>> + dev = pci_get_domain_bus_and_slot(domain, bus, devfn);
> one of the motivations was to remove and re-enumerate rather then
> going thorugh driver's recovery sequence
> was; it might be possible that hotplug capable bridge, the device
> might have changed.
> hence this check will fail
>> + if (dev)
>> + pci_info(dev, "Device recovery from fatal error successful\n");
>> + else
>> + pr_err("AER: Can not find pci_dev for %04x:%02x:%02x.%x\n",
>> + domain, bus,
>> + PCI_SLOT(devfn), PCI_FUNC(devfn));
>> + pci_dev_put(dev);
>> } else {
>> - pci_uevent_ers(dev, PCI_ERS_RESULT_DISCONNECT);
>> - pci_info(dev, "Device recovery from fatal error failed\n");
>> + if (is_bridge_device)
> previously there was no condition.. why is this required now ?
> and it was doing on "dev" while you are doing it on "udev"
is that the reason we dont watnt o use dev after it is removed ? instead
do pci_uevent_ers on bridge ?
>> + pci_uevent_ers(udev, PCI_ERS_RESULT_DISCONNECT);
>> + pr_err("AER: Device %04x:%02x:%02x.%x recovery from fatal error
>> failed\n",
>> + domain, bus, PCI_SLOT(devfn), PCI_FUNC(devfn));
>> }
>>
>> - pci_dev_put(dev);
>> pci_unlock_rescan_remove();
>> }
>
> Regards,
> Oza.
next prev parent reply other threads:[~2018-08-14 12:08 UTC|newest]
Thread overview: 91+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-08-13 16:51 [PATCH 0/1] PCI/AER: prevent pcie_do_fatal_recovery from using device after it is removed Thomas Tai
2018-08-13 16:51 ` [PATCH 1/1] " Thomas Tai
2018-08-14 9:16 ` poza
2018-08-14 9:22 ` poza [this message]
2018-08-14 13:51 ` Thomas Tai
2018-08-15 14:57 ` poza
2018-08-15 15:02 ` Thomas Tai
2018-08-15 15:26 ` poza
2018-08-15 15:43 ` Thomas Tai
2018-08-15 15:59 ` poza
2018-08-15 16:04 ` Thomas Tai
2018-08-15 21:55 ` Benjamin Herrenschmidt
2018-08-15 21:56 ` Benjamin Herrenschmidt
2018-08-16 6:36 ` poza
2018-08-16 6:51 ` Benjamin Herrenschmidt
2018-08-16 6:59 ` Benjamin Herrenschmidt
2018-08-16 8:07 ` poza
2018-08-16 8:12 ` Benjamin Herrenschmidt
2018-08-16 9:03 ` poza
2018-08-16 10:07 ` Benjamin Herrenschmidt
2018-08-16 14:11 ` poza
2018-08-16 23:30 ` Benjamin Herrenschmidt
2018-08-17 10:29 ` poza
2018-08-17 10:44 ` poza
2018-08-18 7:38 ` Benjamin Herrenschmidt
2018-08-16 7:05 ` Benjamin Herrenschmidt
2018-08-16 7:15 ` Benjamin Herrenschmidt
2018-08-16 7:56 ` poza
2018-08-16 8:10 ` Benjamin Herrenschmidt
2018-08-16 8:05 ` poza
2018-08-16 8:15 ` Benjamin Herrenschmidt
2018-08-16 8:22 ` poza
2018-08-16 8:28 ` Benjamin Herrenschmidt
2018-08-16 13:30 ` Thomas Tai
2018-08-16 13:46 ` Sinan Kaya
2018-08-16 23:27 ` Benjamin Herrenschmidt
2018-08-17 6:35 ` poza
2018-08-19 2:24 ` Bjorn Helgaas
2018-08-20 5:09 ` poza
2018-08-20 5:15 ` Benjamin Herrenschmidt
2018-08-20 13:02 ` Thomas Tai
2018-08-20 13:27 ` Benjamin Herrenschmidt
2018-08-19 2:19 ` Bjorn Helgaas
2018-08-19 21:41 ` Sinan Kaya
2018-08-20 2:03 ` Benjamin Herrenschmidt
2018-08-20 5:19 ` poza
2018-08-20 5:33 ` Benjamin Herrenschmidt
2018-08-20 7:56 ` poza
2018-08-20 11:22 ` Benjamin Herrenschmidt
2018-08-20 13:26 ` poza
2018-08-20 21:02 ` Benjamin Herrenschmidt
2018-08-21 5:14 ` poza
2018-08-21 6:06 ` Benjamin Herrenschmidt
2018-08-21 14:37 ` Keith Busch
2018-08-21 15:07 ` Sinan Kaya
2018-08-21 15:29 ` Keith Busch
2018-08-21 15:50 ` Sinan Kaya
2018-08-21 15:55 ` Sinan Kaya
2018-08-21 16:44 ` Keith Busch
2018-08-21 15:30 ` poza
2018-08-21 21:14 ` Benjamin Herrenschmidt
2018-08-21 22:04 ` Keith Busch
2018-08-21 22:33 ` Keith Busch
2018-08-21 23:06 ` Benjamin Herrenschmidt
2018-08-21 23:13 ` Keith Busch
2018-08-22 0:36 ` Benjamin Herrenschmidt
2018-08-30 0:01 ` Keith Busch
2018-08-30 0:10 ` Sinan Kaya
2018-08-30 0:46 ` Keith Busch
2018-08-30 4:26 ` Benjamin Herrenschmidt
2018-08-20 15:53 ` Keith Busch
2018-08-20 16:13 ` poza
2018-08-20 16:32 ` Keith Busch
2018-08-20 21:05 ` Benjamin Herrenschmidt
2018-08-20 21:21 ` Sinan Kaya
2018-08-20 21:35 ` Keith Busch
2018-08-20 21:53 ` Benjamin Herrenschmidt
2018-08-20 22:02 ` Sinan Kaya
2018-08-20 22:04 ` Benjamin Herrenschmidt
2018-08-20 22:13 ` Sinan Kaya
2018-08-20 22:19 ` Benjamin Herrenschmidt
2018-08-22 9:13 ` Lukas Wunner
2018-08-22 14:38 ` Keith Busch
2018-08-22 14:51 ` Sinan Kaya
2018-08-20 22:13 ` Keith Busch
2018-08-20 22:19 ` Benjamin Herrenschmidt
2018-08-21 1:30 ` Keith Busch
2018-08-20 4:37 ` Benjamin Herrenschmidt
2018-08-20 4:39 ` PATCH] Partial revert of "PCI/AER: Handle ERR_FATAL with removal and re-enumeration of devices" Benjamin Herrenschmidt
2018-08-21 19:50 ` Bjorn Helgaas
2018-08-22 4:35 ` poza
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