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author | Bjorn Helgaas <bhelgaas@google.com> | 2021-11-10 12:03:34 -0600 |
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committer | Bjorn Helgaas <bhelgaas@google.com> | 2021-11-11 13:36:22 -0600 |
commit | e0217c5ba10d7bf640f038b2feae58e630f2f958 (patch) | |
tree | d7899667bdfeea595319549c90a184ecf5849490 /drivers/pci/pci-driver.c | |
parent | 68da4e0eaaab421f228eac57cbe7505b136464af (diff) | |
download | linux-e0217c5ba10d7bf640f038b2feae58e630f2f958.tar.bz2 |
Revert "PCI: Use to_pci_driver() instead of pci_dev->driver"
This reverts commit 2a4d9408c9e8b6f6fc150c66f3fef755c9e20d4a.
Robert reported a NULL pointer dereference caused by the PCI core
(local_pci_probe()) calling the i2c_designware_pci driver's
.runtime_resume() method before the .probe() method. i2c_dw_pci_resume()
depends on initialization done by i2c_dw_pci_probe().
Prior to 2a4d9408c9e8 ("PCI: Use to_pci_driver() instead of
pci_dev->driver"), pci_pm_runtime_resume() avoided calling the
.runtime_resume() method because pci_dev->driver had not been set yet.
2a4d9408c9e8 and b5f9c644eb1b ("PCI: Remove struct pci_dev->driver"),
removed pci_dev->driver, replacing it by device->driver, which *has* been
set by this time, so pci_pm_runtime_resume() called the .runtime_resume()
method when it previously had not.
Fixes: 2a4d9408c9e8 ("PCI: Use to_pci_driver() instead of pci_dev->driver")
Link: https://lore.kernel.org/linux-i2c/CAP145pgdrdiMAT7=-iB1DMgA7t_bMqTcJL4N0=6u8kNY3EU0dw@mail.gmail.com/
Reported-by: Robert Święcki <robert@swiecki.net>
Tested-by: Robert Święcki <robert@swiecki.net>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Diffstat (limited to 'drivers/pci/pci-driver.c')
-rw-r--r-- | drivers/pci/pci-driver.c | 33 |
1 files changed, 16 insertions, 17 deletions
diff --git a/drivers/pci/pci-driver.c b/drivers/pci/pci-driver.c index 4c1f46dbfa87..588588cfda48 100644 --- a/drivers/pci/pci-driver.c +++ b/drivers/pci/pci-driver.c @@ -457,7 +457,7 @@ static int pci_device_probe(struct device *dev) static void pci_device_remove(struct device *dev) { struct pci_dev *pci_dev = to_pci_dev(dev); - struct pci_driver *drv = to_pci_driver(dev->driver); + struct pci_driver *drv = pci_dev->driver; if (drv->remove) { pm_runtime_get_sync(dev); @@ -493,7 +493,7 @@ static void pci_device_remove(struct device *dev) static void pci_device_shutdown(struct device *dev) { struct pci_dev *pci_dev = to_pci_dev(dev); - struct pci_driver *drv = to_pci_driver(dev->driver); + struct pci_driver *drv = pci_dev->driver; pm_runtime_resume(dev); @@ -589,7 +589,7 @@ static int pci_pm_reenable_device(struct pci_dev *pci_dev) static int pci_legacy_suspend(struct device *dev, pm_message_t state) { struct pci_dev *pci_dev = to_pci_dev(dev); - struct pci_driver *drv = to_pci_driver(dev->driver); + struct pci_driver *drv = pci_dev->driver; if (drv && drv->suspend) { pci_power_t prev = pci_dev->current_state; @@ -630,7 +630,7 @@ static int pci_legacy_suspend_late(struct device *dev, pm_message_t state) static int pci_legacy_resume(struct device *dev) { struct pci_dev *pci_dev = to_pci_dev(dev); - struct pci_driver *drv = to_pci_driver(dev->driver); + struct pci_driver *drv = pci_dev->driver; pci_fixup_device(pci_fixup_resume, pci_dev); @@ -649,7 +649,7 @@ static void pci_pm_default_suspend(struct pci_dev *pci_dev) static bool pci_has_legacy_pm_support(struct pci_dev *pci_dev) { - struct pci_driver *drv = to_pci_driver(pci_dev->dev.driver); + struct pci_driver *drv = pci_dev->driver; bool ret = drv && (drv->suspend || drv->resume); /* @@ -1242,11 +1242,11 @@ static int pci_pm_runtime_suspend(struct device *dev) int error; /* - * If the device has no driver, we leave it in D0, but it may go to - * D3cold when the bridge above it runtime suspends. Save its - * config space in case that happens. + * If pci_dev->driver is not set (unbound), we leave the device in D0, + * but it may go to D3cold when the bridge above it runtime suspends. + * Save its config space in case that happens. */ - if (!to_pci_driver(dev->driver)) { + if (!pci_dev->driver) { pci_save_state(pci_dev); return 0; } @@ -1303,7 +1303,7 @@ static int pci_pm_runtime_resume(struct device *dev) */ pci_restore_standard_config(pci_dev); - if (!to_pci_driver(dev->driver)) + if (!pci_dev->driver) return 0; pci_fixup_device(pci_fixup_resume_early, pci_dev); @@ -1322,13 +1322,14 @@ static int pci_pm_runtime_resume(struct device *dev) static int pci_pm_runtime_idle(struct device *dev) { + struct pci_dev *pci_dev = to_pci_dev(dev); const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL; /* - * If the device has no driver, it should always remain in D0 - * regardless of the runtime PM status + * If pci_dev->driver is not set (unbound), the device should + * always remain in D0 regardless of the runtime PM status */ - if (!to_pci_driver(dev->driver)) + if (!pci_dev->driver) return 0; if (!pm) @@ -1435,10 +1436,8 @@ static struct pci_driver pci_compat_driver = { */ struct pci_driver *pci_dev_driver(const struct pci_dev *dev) { - struct pci_driver *drv = to_pci_driver(dev->dev.driver); - - if (drv) - return drv; + if (dev->driver) + return dev->driver; else { int i; for (i = 0; i <= PCI_ROM_RESOURCE; i++) |