PCI: Protect pci_driver->sriov_configure() usage with device_lock()
Every method in struct device_driver or structures derived from it like
struct pci_driver MUST provide exclusion vs the driver's ->remove() method,
usually by using device_lock().
Protect use of pci_driver->sriov_configure() by holding the device lock
while calling it.
The PCI core sets the pci_dev->driver pointer in local_pci_probe() before
calling ->probe() and only clears it after ->remove(). This means driver's
->sriov_configure() callback will happily race with probe() and remove(),
most likely leading to BUGs, since drivers don't expect this.
Remove the iov lock completely, since we remove the last user.
[bhelgaas: changelog, thanks to Christoph for locking rule]
Link: http://lkml.kernel.org/r/20170522225023.14010-1-jakub.kicinski@netronome.com
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
diff --git a/drivers/pci/pci-sysfs.c b/drivers/pci/pci-sysfs.c
index 31e9961..7755559 100644
--- a/drivers/pci/pci-sysfs.c
+++ b/drivers/pci/pci-sysfs.c
@@ -472,7 +472,6 @@
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;
@@ -483,7 +482,7 @@
if (num_vfs > pci_sriov_get_totalvfs(pdev))
return -ERANGE;
- mutex_lock(&iov->dev->sriov->lock);
+ device_lock(&pdev->dev);
if (num_vfs == pdev->sriov->num_VFs)
goto exit;
@@ -518,7 +517,7 @@
num_vfs, ret);
exit:
- mutex_unlock(&iov->dev->sriov->lock);
+ device_unlock(&pdev->dev);
if (ret < 0)
return ret;