diff options
| author | Emil Tantilov <emil.s.tantilov@intel.com> | 2017-01-06 13:59:08 -0800 |
|---|---|---|
| committer | Bjorn Helgaas <bhelgaas@google.com> | 2017-02-03 13:42:38 -0600 |
| commit | 5b0948dfe138f0837699f46f5877f4f81c252dac (patch) | |
| tree | eb67c2325c5dea87be81c16ce19b872dd153ac6a /drivers/pci/pci-sysfs.c | |
| parent | 7184f5b451cf3dc61de79091d235b5d2bba2782d (diff) | |
| download | linux-5b0948dfe138f0837699f46f5877f4f81c252dac.tar.bz2 | |
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>
Diffstat (limited to 'drivers/pci/pci-sysfs.c')
| -rw-r--r-- | drivers/pci/pci-sysfs.c | 23 |
1 files changed, 16 insertions, 7 deletions
diff --git a/drivers/pci/pci-sysfs.c b/drivers/pci/pci-sysfs.c index 066628776e1b..25d010d449a3 100644 --- a/drivers/pci/pci-sysfs.c +++ b/drivers/pci/pci-sysfs.c @@ -472,6 +472,7 @@ static ssize_t sriov_numvfs_store(struct device *dev, const char *buf, size_t count) { struct pci_dev *pdev = to_pci_dev(dev); + struct pci_sriov *iov = pdev->sriov; int ret; u16 num_vfs; @@ -482,38 +483,46 @@ static ssize_t sriov_numvfs_store(struct device *dev, if (num_vfs > pci_sriov_get_totalvfs(pdev)) return -ERANGE; + mutex_lock(&iov->dev->sriov->lock); + if (num_vfs == pdev->sriov->num_VFs) - return count; /* no change */ + goto exit; /* is PF driver loaded w/callback */ if (!pdev->driver || !pdev->driver->sriov_configure) { dev_info(&pdev->dev, "Driver doesn't support SRIOV configuration via sysfs\n"); - return -ENOSYS; + ret = -ENOENT; + goto exit; } if (num_vfs == 0) { /* disable VFs */ ret = pdev->driver->sriov_configure(pdev, 0); - if (ret < 0) - return ret; - return count; + goto exit; } /* enable VFs */ if (pdev->sriov->num_VFs) { dev_warn(&pdev->dev, "%d VFs already enabled. Disable before enabling %d VFs\n", pdev->sriov->num_VFs, num_vfs); - return -EBUSY; + ret = -EBUSY; + goto exit; } ret = pdev->driver->sriov_configure(pdev, num_vfs); if (ret < 0) - return ret; + goto exit; if (ret != num_vfs) dev_warn(&pdev->dev, "%d VFs requested; only %d enabled\n", num_vfs, ret); +exit: + mutex_unlock(&iov->dev->sriov->lock); + + if (ret < 0) + return ret; + return count; } |