linux/drivers/pci
dingtianhong 0e40523287 PCI: fix oops when try to find Root Port for a PCI device
Eric report a oops when booting the system after applying
the commit a99b646afa ("PCI: Disable PCIe Relaxed..."):

[    4.241029] BUG: unable to handle kernel NULL pointer dereference at 0000000000000050
[    4.247001] IP: pci_find_pcie_root_port+0x62/0x80
[    4.253011] PGD 0
[    4.253011] P4D 0
[    4.253011]
[    4.258013] Oops: 0000 [#1] SMP DEBUG_PAGEALLOC
[    4.262015] Modules linked in:
[    4.265005] CPU: 31 PID: 1 Comm: swapper/0 Not tainted 4.13.0-dbx-DEV #316
[    4.271002] Hardware name: Intel RML,PCH/Iota_QC_19, BIOS 2.40.0 06/22/2016
[    4.279002] task: ffffa2ee38cfa040 task.stack: ffffa51ec0004000
[    4.285001] RIP: 0010:pci_find_pcie_root_port+0x62/0x80
[    4.290012] RSP: 0000:ffffa51ec0007ab8 EFLAGS: 00010246
[    4.295003] RAX: 0000000000000000 RBX: ffffa2ee36bae000 RCX: 0000000000000006
[    4.303002] RDX: 000000000000081c RSI: ffffa2ee38cfa8c8 RDI: ffffa2ee36bae000
[    4.310013] RBP: ffffa51ec0007b58 R08: 0000000000000001 R09: 0000000000000000
[    4.317001] R10: 0000000000000000 R11: 0000000000000000 R12: ffffa51ec0007ad0
[    4.324005] R13: ffffa2ee36bae098 R14: 0000000000000002 R15: ffffa2ee37204818
[    4.331002] FS:  0000000000000000(0000) GS:ffffa2ee3fcc0000(0000) knlGS:0000000000000000
[    4.339002] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[    4.345001] CR2: 0000000000000050 CR3: 000000401000f000 CR4: 00000000001406e0
[    4.351002] Call Trace:
[    4.354012]  ? pci_configure_device+0x19f/0x570
[    4.359002]  ? pci_conf1_read+0xb8/0xf0
[    4.363002]  ? raw_pci_read+0x23/0x40
[    4.366011]  ? pci_read+0x2c/0x30
[    4.370014]  ? pci_read_config_word+0x67/0x70
[    4.374012]  pci_device_add+0x28/0x230
[    4.378012]  ? pci_vpd_f0_read+0x50/0x80
[    4.382014]  pci_scan_single_device+0x96/0xc0
[    4.386012]  pci_scan_slot+0x79/0xf0
[    4.389001]  pci_scan_child_bus+0x31/0x180
[    4.394014]  acpi_pci_root_create+0x1c6/0x240
[    4.398013]  pci_acpi_scan_root+0x15f/0x1b0
[    4.402012]  acpi_pci_root_add+0x2e6/0x400
[    4.406012]  ? acpi_evaluate_integer+0x37/0x60
[    4.411002]  acpi_bus_attach+0xdf/0x200
[    4.415002]  acpi_bus_attach+0x6a/0x200
[    4.418014]  acpi_bus_attach+0x6a/0x200
[    4.422013]  acpi_bus_scan+0x38/0x70
[    4.426011]  acpi_scan_init+0x10c/0x271
[    4.429001]  acpi_init+0x2fa/0x348
[    4.433004]  ? acpi_sleep_proc_init+0x2d/0x2d
[    4.437001]  do_one_initcall+0x43/0x169
[    4.441001]  kernel_init_freeable+0x1d0/0x258
[    4.445003]  ? rest_init+0xe0/0xe0
[    4.449001]  kernel_init+0xe/0x150

====================== cut here =============================

It looks like the pci_find_pcie_root_port() was trying to
find the Root Port for the PCI device which is the Root
Port already, it will return NULL and trigger the problem,
so check the highest_pcie_bridge to fix thie problem.

Fixes: a99b646afa ("PCI: Disable PCIe Relaxed Ordering if unsupported")
Fixes: c56d4450eb ("PCI: Turn off Request Attributes to avoid Chelsio T5 Completion erratum")
Reported-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: Ding Tianhong <dingtianhong@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-15 17:25:16 -07:00
..
dwc Merge branch 'pci/host-qcom' into next 2017-07-04 11:00:57 -05:00
endpoint PCI: endpoint: Select CRC32 to fix test build error 2017-06-12 15:46:13 -05:00
host PCI: rockchip: Check for pci_scan_root_bus_bridge() failure correctly 2017-07-12 12:50:11 -05:00
hotplug Annotation of module parameters that specify device settings 2017-05-10 19:13:03 -07:00
pcie Merge branch 'pm-pci' 2017-07-14 13:15:49 +02:00
switch Merge branch 'pci/switchtec' into next 2017-07-02 18:51:10 -05:00
access.c PCI: Provide Kconfig option for lockless config space accessors 2017-06-28 22:32:56 +02:00
ats.c PCI: Restore PRI and PASID state after Function-Level Reset 2017-05-30 15:40:50 -05:00
bus.c PCI: Autosense device removal in pci_bridge_d3_update() 2016-11-17 18:44:56 -06:00
ecam.c PCI: ECAM: Map config region with pci_remap_cfgspace() 2017-04-24 13:53:14 -05:00
host-bridge.c cxl: use pcibios_free_controller_deferred() when removing vPHBs 2016-08-22 11:09:33 +10:00
hotplug-pci.c
htirq.c
iov.c PCI: Protect pci_driver->sriov_configure() usage with device_lock() 2017-06-14 17:41:19 -05:00
irq.c pci-v4.12-changes 2017-05-08 19:03:25 -07:00
Kconfig PCI: Provide Kconfig option for lockless config space accessors 2017-06-28 22:32:56 +02:00
Makefile PCI: Build setup-irq.o on all arches 2017-07-02 16:14:27 -05:00
mmap.c PCI: Add I/O BAR support to generic pci_mmap_resource_range() 2017-04-20 08:47:47 -05:00
msi.c pci-v4.13-changes 2017-07-08 15:51:57 -07:00
of.c PCI/MSI: Use of_msi_get_domain instead of open-coded "msi-parent" parsing 2015-10-16 13:07:14 +01:00
pci-acpi.c PM / core: Drop run_wake flag from struct dev_pm_info 2017-06-28 01:52:52 +02:00
pci-driver.c Merge branch 'pm-pci' 2017-07-14 13:15:49 +02:00
pci-label.c pci-v4.13-changes 2017-07-08 15:51:57 -07:00
pci-mid.c PCI / PM: Simplify device wakeup settings code 2017-06-28 01:52:45 +02:00
pci-stub.c
pci-sysfs.c Merge branch 'pci/virtualization' into next 2017-07-03 08:00:29 -05:00
pci.c PCI: fix oops when try to find Root Port for a PCI device 2017-08-15 17:25:16 -07:00
pci.h Merge branch 'pm-pci' 2017-07-14 13:15:49 +02:00
probe.c PCI: Disable PCIe Relaxed Ordering if unsupported 2017-08-14 22:14:50 -07:00
proc.c PCI: Add BAR index argument to pci_mmap_page_range() 2017-04-20 08:47:47 -05:00
quirks.c PCI: Disable Relaxed Ordering Attributes for AMD A1100 2017-08-14 22:14:50 -07:00
remove.c PCI: Autosense device removal in pci_bridge_d3_update() 2016-11-17 18:44:56 -06:00
rom.c PCI: Add comments about ROM BAR updating 2016-11-29 18:05:09 -06:00
search.c PCI: Add device flag PCI_DEV_FLAGS_BRIDGE_XLATE_ROOT 2017-04-13 18:49:50 -05:00
setup-bus.c PCI: Fix calculation of bridge window's size and alignment 2017-04-18 14:47:20 -05:00
setup-irq.c PCI: Add pci_assign_irq() function and have pci_fixup_irqs() use it 2017-07-02 16:14:28 -05:00
setup-res.c PCI: Make PCI_ROM_ADDRESS_MASK a 32-bit constant 2017-04-18 14:46:57 -05:00
slot.c locking/atomic, kref: Add kref_read() 2017-01-14 11:37:18 +01:00
syscall.c Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
vc.c PCI: Fix unaligned accesses in VC code 2016-06-20 13:24:20 -05:00
vpd.c
xen-pcifront.c xen: make use of xenbus_read_unsigned() in xen-pcifront 2016-11-07 13:55:26 +01:00