From 5b0948dfe138f0837699f46f5877f4f81c252dac Mon Sep 17 00:00:00 2001 From: Emil Tantilov Date: Fri, 6 Jan 2017 13:59:08 -0800 Subject: 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:[] [] pci_iov_release+0x57/0x60 Call Trace: [] pci_release_dev+0x26/0x70 [] device_release+0x3e/0xb0 [] kobject_cleanup+0x67/0x180 [] kobject_put+0x2d/0x60 [] put_device+0x17/0x20 [] pci_dev_put+0x1a/0x20 [] pci_get_dev_by_id+0x5b/0x90 [] pci_get_subsys+0x35/0x40 [] pci_get_device+0x18/0x20 [] pci_get_domain_bus_and_slot+0x2b/0x60 [] pci_iov_remove_virtfn+0x57/0x180 [] pci_disable_sriov+0x65/0x140 [] ixgbe_disable_sriov+0xc7/0x1d0 [ixgbe] [] ixgbe_pci_sriov_configure+0x3d/0x170 [ixgbe] [] sriov_numvfs_store+0xdc/0x130 ... RIP [] pci_iov_release+0x57/0x60 Use the existing mutex lock to protect each enable/disable operation. Signed-off-by: Emil Tantilov Signed-off-by: Bjorn Helgaas Reviewed-by: Gavin Shan CC: Alexander Duyck --- drivers/pci/iov.c | 7 ------- 1 file changed, 7 deletions(-) (limited to 'drivers/pci/iov.c') diff --git a/drivers/pci/iov.c b/drivers/pci/iov.c index 47227820406d..2479ae876482 100644 --- a/drivers/pci/iov.c +++ b/drivers/pci/iov.c @@ -124,7 +124,6 @@ int pci_iov_add_virtfn(struct pci_dev *dev, int id, int reset) struct pci_sriov *iov = dev->sriov; struct pci_bus *bus; - mutex_lock(&iov->dev->sriov->lock); bus = virtfn_add_bus(dev->bus, pci_iov_virtfn_bus(dev, id)); if (!bus) goto failed; @@ -162,7 +161,6 @@ int pci_iov_add_virtfn(struct pci_dev *dev, int id, int reset) __pci_reset_function(virtfn); pci_device_add(virtfn, virtfn->bus); - mutex_unlock(&iov->dev->sriov->lock); pci_bus_add_device(virtfn); sprintf(buf, "virtfn%u", id); @@ -181,12 +179,10 @@ failed2: sysfs_remove_link(&dev->dev.kobj, buf); failed1: pci_dev_put(dev); - mutex_lock(&iov->dev->sriov->lock); pci_stop_and_remove_bus_device(virtfn); failed0: virtfn_remove_bus(dev->bus, bus); failed: - mutex_unlock(&iov->dev->sriov->lock); return rc; } @@ -195,7 +191,6 @@ void pci_iov_remove_virtfn(struct pci_dev *dev, int id, int reset) { char buf[VIRTFN_ID_LEN]; struct pci_dev *virtfn; - struct pci_sriov *iov = dev->sriov; virtfn = pci_get_domain_bus_and_slot(pci_domain_nr(dev->bus), pci_iov_virtfn_bus(dev, id), @@ -218,10 +213,8 @@ void pci_iov_remove_virtfn(struct pci_dev *dev, int id, int reset) if (virtfn->dev.kobj.sd) sysfs_remove_link(&virtfn->dev.kobj, "physfn"); - mutex_lock(&iov->dev->sriov->lock); pci_stop_and_remove_bus_device(virtfn); virtfn_remove_bus(dev->bus, virtfn->bus); - mutex_unlock(&iov->dev->sriov->lock); /* balance pci_get_domain_bus_and_slot() */ pci_dev_put(virtfn); -- cgit v1.2.3-59-g8ed1b