linux/drivers/pci
Emil Tantilov 5b0948dfe1 PCI: Lock each enable/disable num_vfs operation in sysfs
Enabling/disabling SRIOV via sysfs by echo-ing multiple values
simultaneously:

  # echo 63 > /sys/class/net/ethX/device/sriov_numvfs&
  # echo 63 > /sys/class/net/ethX/device/sriov_numvfs

  # sleep 5

  # echo 0 > /sys/class/net/ethX/device/sriov_numvfs&
  # echo 0 > /sys/class/net/ethX/device/sriov_numvfs

results in the following bug:

  kernel BUG at drivers/pci/iov.c:495!
  invalid opcode: 0000 [#1] SMP
  CPU: 1 PID: 8050 Comm: bash Tainted: G   W   4.9.0-rc7-net-next #2092
  RIP: 0010:[<ffffffff813b1647>]
	    [<ffffffff813b1647>] pci_iov_release+0x57/0x60

  Call Trace:
   [<ffffffff81391726>] pci_release_dev+0x26/0x70
   [<ffffffff8155be6e>] device_release+0x3e/0xb0
   [<ffffffff81365ee7>] kobject_cleanup+0x67/0x180
   [<ffffffff81365d9d>] kobject_put+0x2d/0x60
   [<ffffffff8155bc27>] put_device+0x17/0x20
   [<ffffffff8139c08a>] pci_dev_put+0x1a/0x20
   [<ffffffff8139cb6b>] pci_get_dev_by_id+0x5b/0x90
   [<ffffffff8139cca5>] pci_get_subsys+0x35/0x40
   [<ffffffff8139ccc8>] pci_get_device+0x18/0x20
   [<ffffffff8139ccfb>] pci_get_domain_bus_and_slot+0x2b/0x60
   [<ffffffff813b09e7>] pci_iov_remove_virtfn+0x57/0x180
   [<ffffffff813b0b95>] pci_disable_sriov+0x65/0x140
   [<ffffffffa00a1af7>] ixgbe_disable_sriov+0xc7/0x1d0 [ixgbe]
   [<ffffffffa00a1e9d>] ixgbe_pci_sriov_configure+0x3d/0x170 [ixgbe]
   [<ffffffff8139d28c>] sriov_numvfs_store+0xdc/0x130
  ...
  RIP  [<ffffffff813b1647>] pci_iov_release+0x57/0x60

Use the existing mutex lock to protect each enable/disable operation.

Signed-off-by: Emil Tantilov <emil.s.tantilov@intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Gavin Shan <gwshan@linux.vnet.ibm.com>
CC: Alexander Duyck <alexander.h.duyck@intel.com>
2017-02-03 13:42:38 -06:00
..
host pci-v4.10-changes 2016-12-15 12:46:48 -08:00
hotplug Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
pcie pci-v4.10-changes 2016-12-15 12:46:48 -08:00
access.c PCI: Warn on possible RW1C corruption for sub-32 bit config writes 2016-11-21 16:25:39 -06:00
ats.c
bus.c PCI: Autosense device removal in pci_bridge_d3_update() 2016-11-17 18:44:56 -06:00
ecam.c PCI: Add MCFG quirks for Qualcomm QDF2432 host controller 2016-12-06 13:45:49 -06:00
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: Lock each enable/disable num_vfs operation in sysfs 2017-02-03 13:42:38 -06:00
irq.c
Kconfig PCI/MSI: Enable PCI_MSI_IRQ_DOMAIN support for ARC 2016-09-06 10:53:32 -05:00
Makefile x86/platform/intel-mid: Add Power Management Unit driver 2016-06-15 10:10:49 +02:00
msi.c pci-v4.10-changes 2016-12-15 12:46:48 -08:00
of.c
pci-acpi.c Merge branch 'pci/pm' into next 2016-12-12 11:25:04 -06:00
pci-driver.c Merge branch 'pci/pm' into next 2016-10-03 09:43:21 -05:00
pci-label.c PCI: Fix broken URL for Dell biosdevname 2016-02-29 12:03:19 -06:00
pci-mid.c pci-v4.10-changes 2016-12-15 12:46:48 -08:00
pci-stub.c
pci-sysfs.c PCI: Lock each enable/disable num_vfs operation in sysfs 2017-02-03 13:42:38 -06:00
pci.c Merge branch 'pci/virtualization' into next 2016-12-12 11:25:05 -06:00
pci.h PCI: Lock each enable/disable num_vfs operation in sysfs 2017-02-03 13:42:38 -06:00
probe.c pci-v4.10-changes 2016-12-15 12:46:48 -08:00
proc.c Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
quirks.c PCI: Add ACS quirk for Intel Union Point 2017-01-28 14:46:02 -06:00
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 support for multiple DMA aliases 2016-04-11 14:34:32 -05:00
setup-bus.c x86/ioapic: Ignore root bridges without a companion ACPI device 2016-09-10 20:30:31 +02:00
setup-irq.c
setup-res.c Merge branch 'pci/host-rockchip' into next 2016-12-12 11:25:11 -06:00
slot.c
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