diff options
| author | Dave Jiang <dave.jiang@intel.com> | 2024-05-02 19:57:31 +0300 |
|---|---|---|
| committer | Bjorn Helgaas <bhelgaas@google.com> | 2024-05-08 21:19:20 +0300 |
| commit | 7e89efc6e9e402839643cb297bab14055c547f07 (patch) | |
| tree | a3dd3510c8f20c5458a7847af081ab5a393eedda /drivers/pci | |
| parent | 962f1e79e7acfb30207a378894b1bbf6742e6212 (diff) | |
| download | linux-7e89efc6e9e402839643cb297bab14055c547f07.tar.xz | |
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')
| -rw-r--r-- | drivers/pci/access.c | 4 | ||||
| -rw-r--r-- | drivers/pci/pci.c | 13 | ||||
| -rw-r--r-- | drivers/pci/probe.c | 3 |
3 files changed, 20 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); diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index e5f243dd4288..c63142352844 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -4879,6 +4879,7 @@ void __weak pcibios_reset_secondary_bus(struct pci_dev *dev) */ int pci_bridge_secondary_bus_reset(struct pci_dev *dev) { + lock_map_assert_held(&dev->cfg_access_lock); pcibios_reset_secondary_bus(dev); return pci_bridge_wait_for_secondary_bus(dev, "bus reset"); @@ -5245,11 +5246,20 @@ void pci_init_reset_methods(struct pci_dev *dev) */ int pci_reset_function(struct pci_dev *dev) { + struct pci_dev *bridge; int rc; if (!pci_reset_supported(dev)) return -ENOTTY; + /* + * If there's no upstream bridge, no locking is needed since there is + * no upstream bridge configuration to hold consistent. + */ + bridge = pci_upstream_bridge(dev); + if (bridge) + pci_dev_lock(bridge); + pci_dev_lock(dev); pci_dev_save_and_disable(dev); @@ -5258,6 +5268,9 @@ int pci_reset_function(struct pci_dev *dev) pci_dev_restore(dev); pci_dev_unlock(dev); + if (bridge) + pci_dev_unlock(bridge); + return rc; } EXPORT_SYMBOL_GPL(pci_reset_function); diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c index 1325fbae2f28..a3da776bf986 100644 --- a/drivers/pci/probe.c +++ b/drivers/pci/probe.c @@ -2543,6 +2543,9 @@ void pci_device_add(struct pci_dev *dev, struct pci_bus *bus) dev->dev.dma_mask = &dev->dma_mask; dev->dev.dma_parms = &dev->dma_parms; dev->dev.coherent_dma_mask = 0xffffffffull; + lockdep_register_key(&dev->cfg_access_key); + lockdep_init_map(&dev->cfg_access_lock, dev_name(&dev->dev), + &dev->cfg_access_key, 0); dma_set_max_seg_size(&dev->dev, 65536); dma_set_seg_boundary(&dev->dev, 0xffffffff); |