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author | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2014-02-03 02:22:07 +0100 |
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committer | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2014-02-03 22:28:02 +0100 |
commit | 2d7c1b77dd59387070aab355532dd157f888325c (patch) | |
tree | 7059fc37413f11ff25b87d78d6c068b8c0091734 | |
parent | 38dbfb59d1175ef458d006556061adeaa8751b72 (diff) | |
download | lwn-2d7c1b77dd59387070aab355532dd157f888325c.tar.gz lwn-2d7c1b77dd59387070aab355532dd157f888325c.zip |
ACPI / hotplug / PCI: Remove entries from bus->devices in reverse order
According to the changelog of commit 29ed1f29b68a (PCI: pciehp: Fix null
pointer deref when hot-removing SR-IOV device) it is unsafe to walk the
bus->devices list of a PCI bus and remove devices from it in direct order,
because that may lead to NULL pointer dereferences related to virtual
functions.
For this reason, change all of the bus->devices list walks in
acpiphp_glue.c during which devices may be removed to be carried out in
reverse order.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Tested-by: Mika Westerberg <mika.westerberg@linux.intel.com>
-rw-r--r-- | drivers/pci/hotplug/acpiphp_glue.c | 8 |
1 files changed, 4 insertions, 4 deletions
diff --git a/drivers/pci/hotplug/acpiphp_glue.c b/drivers/pci/hotplug/acpiphp_glue.c index cd929aed3613..6a4b4b734fbd 100644 --- a/drivers/pci/hotplug/acpiphp_glue.c +++ b/drivers/pci/hotplug/acpiphp_glue.c @@ -742,7 +742,7 @@ static void trim_stale_devices(struct pci_dev *dev) /* The device is a bridge. so check the bus below it. */ pm_runtime_get_sync(&dev->dev); - list_for_each_entry_safe(child, tmp, &bus->devices, bus_list) + list_for_each_entry_safe_reverse(child, tmp, &bus->devices, bus_list) trim_stale_devices(child); pm_runtime_put(&dev->dev); @@ -773,8 +773,8 @@ static void acpiphp_check_bridge(struct acpiphp_bridge *bridge) ; /* do nothing */ } else if (get_slot_status(slot) == ACPI_STA_ALL) { /* remove stale devices if any */ - list_for_each_entry_safe(dev, tmp, &bus->devices, - bus_list) + list_for_each_entry_safe_reverse(dev, tmp, + &bus->devices, bus_list) if (PCI_SLOT(dev->devfn) == slot->device) trim_stale_devices(dev); @@ -805,7 +805,7 @@ static void acpiphp_sanitize_bus(struct pci_bus *bus) int i; unsigned long type_mask = IORESOURCE_IO | IORESOURCE_MEM; - list_for_each_entry_safe(dev, tmp, &bus->devices, bus_list) { + list_for_each_entry_safe_reverse(dev, tmp, &bus->devices, bus_list) { for (i=0; i<PCI_BRIDGE_RESOURCES; i++) { struct resource *res = &dev->resource[i]; if ((res->flags & type_mask) && !res->start && |