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| author |   Alex Chiang <achiang@hp.com> | 2008-07-01 20:02:23 -0600 |
|---|---|---|
| committer |   Jesse Barnes <jbarnes@virtuousgeek.org> | 2008-07-02 11:27:30 -0700 |
| commit | a13307cef8bf51990ef1d525b1cbdcc2cfe07e2a (patch) | |
| tree | 3098b0057aa09f53c9ecd485fc147f135eecfc33 /drivers/pci | |
| parent | PCI: Limit VPD read/write lengths for Broadcom 5706, 5708, 5709 rev. (diff) | |
| download | linux-dev-a13307cef8bf51990ef1d525b1cbdcc2cfe07e2a.tar.xz linux-dev-a13307cef8bf51990ef1d525b1cbdcc2cfe07e2a.zip | |
PCI: acpiphp: cleanup notify handler on all root bridges
During the development of the physical PCI slot patch series, Gary Hade
kept on reporting strange oopses due to interactions between pci_slot
and acpiphp.
http://lkml.org/lkml/2007/11/28/319
find_root_bridges() unconditionally installs
handle_hotplug_event_bridge() as an ACPI_SYSTEM_NOTIFY handler for all
root bridges.
However, during module cleanup, remove_bridge() will only remove the
notify handler iff the root bridge had a hot-pluggable slot directly
underneath. That is:
root bridge -> hotplug slot
But, if the topology looks like either of the following:
root bridge -> non-hotplug slot
root bridge -> p2p bridge -> hotplug slot
Then we currently do not remove the notify handler from that root
bridge.
This can cause a kernel oops if we modprobe acpiphp later and it gets
loaded somewhere else in memory. If the root bridge then receives a
hotplug event, it will then attempt to call a stale, non-existent notify
handler and we blow up.
Much thanks goes to Gary Hade for his persistent debugging efforts.
Signed-off-by: Alex Chiang <achiang@hp.com>
Signed-off-by: Gary Hade <garyhade@us.ibm.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Diffstat (limited to 'drivers/pci')
| -rw-r--r-- | drivers/pci/hotplug/acpiphp_glue.c | 17 |
1 files changed, 14 insertions, 3 deletions
diff --git a/drivers/pci/hotplug/acpiphp_glue.c b/drivers/pci/hotplug/acpiphp_glue.c index 648596d469f6..91156f85a926 100644 --- a/drivers/pci/hotplug/acpiphp_glue.c +++ b/drivers/pci/hotplug/acpiphp_glue.c @@ -700,9 +700,10 @@ cleanup_p2p_bridge(acpi_handle handle, u32 lvl, void *context, void **rv) acpi_walk_namespace(ACPI_TYPE_DEVICE, handle, (u32)1, cleanup_p2p_bridge, NULL, NULL); - if (!(bridge = acpiphp_handle_to_bridge(handle))) - return AE_OK; - cleanup_bridge(bridge); + bridge = acpiphp_handle_to_bridge(handle); + if (bridge) + cleanup_bridge(bridge); + return AE_OK; } @@ -715,9 +716,19 @@ static void remove_bridge(acpi_handle handle) acpi_walk_namespace(ACPI_TYPE_DEVICE, handle, (u32)1, cleanup_p2p_bridge, NULL, NULL); + /* + * On root bridges with hotplug slots directly underneath (ie, + * no p2p bridge inbetween), we call cleanup_bridge(). + * + * The else clause cleans up root bridges that either had no + * hotplug slots at all, or had a p2p bridge underneath. + */ bridge = acpiphp_handle_to_bridge(handle); if (bridge) cleanup_bridge(bridge); + else + acpi_remove_notify_handler(handle, ACPI_SYSTEM_NOTIFY, + handle_hotplug_event_bridge); } static struct pci_dev * get_apic_pci_info(acpi_handle handle) |