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| author | Dave Jiang <dave.jiang@intel.com> | 2024-05-02 09:57:31 -0700 |
|---|---|---|
| committer | Bjorn Helgaas <bhelgaas@google.com> | 2024-05-08 13:19:20 -0500 |
| commit | 7e89efc6e9e402839643cb297bab14055c547f07 (patch) | |
| tree | a3dd3510c8f20c5458a7847af081ab5a393eedda /drivers/pci/access.c | |
| parent | 962f1e79e7acfb30207a378894b1bbf6742e6212 (diff) | |
| download | lwn-7e89efc6e9e402839643cb297bab14055c547f07.tar.gz lwn-7e89efc6e9e402839643cb297bab14055c547f07.zip | |
PCI: Lock upstream bridge for pci_reset_function()
Fix a long-standing locking gap for missing pci_cfg_access_lock() while
manipulating bridge reset registers and configuration during
pci_reset_bus_function().
If there is an upstream bridge, lock it before locking the device itself.
pci_dev_lock() calls pci_cfg_access_lock(), which blocks the writing of PCI
config space by user space.
Add lockdep assertion via pci_dev->cfg_access_lock to verify
pci_dev->block_cfg_access is set.
Co-developed-by: Dan Williams <dan.j.williams@intel.com>
Link: https://lore.kernel.org/r/20240502165851.1948523-3-dave.jiang@intel.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
[bhelgaas: commit log]
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Diffstat (limited to 'drivers/pci/access.c')
| -rw-r--r-- | drivers/pci/access.c | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/drivers/pci/access.c b/drivers/pci/access.c index 6449056b57dd..36f10c7f9ef5 100644 --- a/drivers/pci/access.c +++ b/drivers/pci/access.c @@ -275,6 +275,8 @@ void pci_cfg_access_lock(struct pci_dev *dev) { might_sleep(); + lock_map_acquire(&dev->cfg_access_lock); + raw_spin_lock_irq(&pci_lock); if (dev->block_cfg_access) pci_wait_cfg(dev); @@ -329,6 +331,8 @@ void pci_cfg_access_unlock(struct pci_dev *dev) raw_spin_unlock_irqrestore(&pci_lock, flags); wake_up_all(&pci_cfg_wait); + + lock_map_release(&dev->cfg_access_lock); } EXPORT_SYMBOL_GPL(pci_cfg_access_unlock); |