| Message ID | 20090330165019.18855.69386.stgit@bob.kio (mailing list archive) |
|---|---|
| State | Accepted, archived |
| Headers | show |
I confirmed this patch fix the kernel oops problem I reported. Reviewed-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com> Tested-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com> By the way, /sys/bus/pci/slots/<slot> directory by pci_slot are remaining even after the parent bridge/bus of the slots are removed. At this point, pci_slot is working with struct pci_bus for the already disabled pci bus. This might cause something problem. So I think we also need something mechanism to unregister slots by pci_slot when the parent bus is removed. Thanks, Kenji Kaneshige Alex Chiang wrote: > If a logical hot unplug (remove) is performed on a physical PCI slot's > parent bridge, and then pci_slot is unloaded, we will encounter an oops: > > [<ffffffff803a788a>] kobject_release+0x9a/0x290 > [<ffffffff803a77f0>] ? kobject_release+0x0/0x290 > [<ffffffff803a8ce7>] kref_put+0x37/0x80 > [<ffffffff803a76f7>] kobject_put+0x27/0x60 > [<ffffffff803bebcc>] ? pci_destroy_slot+0x3c/0xc0 > [<ffffffff803bebd5>] pci_destroy_slot+0x45/0xc0 > [<ffffffffa000f05c>] acpi_pci_slot_remove+0x5c/0x91 [pci_slot] > [<ffffffff8040064b>] acpi_pci_unregister_driver+0x4b/0x62 > [<ffffffffa000f5c8>] acpi_pci_slot_exit+0x10/0x12 [pci_slot] > [<ffffffff80276ce1>] sys_delete_module+0x161/0x250 > > We need to grab a reference to the parent PCI bus, which will pin > the bus and prevent it from being released until pci_slot is unloaded. > > Cc: lenb@kernel.org > Reported-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com> > Signed-off-by: Alex Chiang <achiang@hp.com> > --- > > drivers/acpi/pci_slot.c | 5 +++++ > 1 files changed, 5 insertions(+), 0 deletions(-) > > diff --git a/drivers/acpi/pci_slot.c b/drivers/acpi/pci_slot.c > index cd1f446..12158e0 100644 > --- a/drivers/acpi/pci_slot.c > +++ b/drivers/acpi/pci_slot.c > @@ -164,6 +164,8 @@ register_slot(acpi_handle handle, u32 lvl, void *context, void **rv) > list_add(&slot->list, &slot_list); > mutex_unlock(&slot_list_lock); > > + get_device(&pci_bus->dev); > + > dbg("pci_slot: %p, pci_bus: %x, device: %d, name: %s\n", > pci_slot, pci_bus->number, device, name); > > @@ -310,12 +312,15 @@ static void > acpi_pci_slot_remove(acpi_handle handle) > { > struct acpi_pci_slot *slot, *tmp; > + struct pci_bus *pbus; > > mutex_lock(&slot_list_lock); > list_for_each_entry_safe(slot, tmp, &slot_list, list) { > if (slot->root_handle == handle) { > list_del(&slot->list); > + pbus = slot->pci_slot->bus; > pci_destroy_slot(slot->pci_slot); > + put_device(&pbus->dev); > kfree(slot); > } > } > > -- > To unsubscribe from this list: send the line "unsubscribe linux-pci" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > > -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/drivers/acpi/pci_slot.c b/drivers/acpi/pci_slot.c index cd1f446..12158e0 100644 --- a/drivers/acpi/pci_slot.c +++ b/drivers/acpi/pci_slot.c @@ -164,6 +164,8 @@ register_slot(acpi_handle handle, u32 lvl, void *context, void **rv) list_add(&slot->list, &slot_list); mutex_unlock(&slot_list_lock); + get_device(&pci_bus->dev); + dbg("pci_slot: %p, pci_bus: %x, device: %d, name: %s\n", pci_slot, pci_bus->number, device, name); @@ -310,12 +312,15 @@ static void acpi_pci_slot_remove(acpi_handle handle) { struct acpi_pci_slot *slot, *tmp; + struct pci_bus *pbus; mutex_lock(&slot_list_lock); list_for_each_entry_safe(slot, tmp, &slot_list, list) { if (slot->root_handle == handle) { list_del(&slot->list); + pbus = slot->pci_slot->bus; pci_destroy_slot(slot->pci_slot); + put_device(&pbus->dev); kfree(slot); } }
If a logical hot unplug (remove) is performed on a physical PCI slot's parent bridge, and then pci_slot is unloaded, we will encounter an oops: [<ffffffff803a788a>] kobject_release+0x9a/0x290 [<ffffffff803a77f0>] ? kobject_release+0x0/0x290 [<ffffffff803a8ce7>] kref_put+0x37/0x80 [<ffffffff803a76f7>] kobject_put+0x27/0x60 [<ffffffff803bebcc>] ? pci_destroy_slot+0x3c/0xc0 [<ffffffff803bebd5>] pci_destroy_slot+0x45/0xc0 [<ffffffffa000f05c>] acpi_pci_slot_remove+0x5c/0x91 [pci_slot] [<ffffffff8040064b>] acpi_pci_unregister_driver+0x4b/0x62 [<ffffffffa000f5c8>] acpi_pci_slot_exit+0x10/0x12 [pci_slot] [<ffffffff80276ce1>] sys_delete_module+0x161/0x250 We need to grab a reference to the parent PCI bus, which will pin the bus and prevent it from being released until pci_slot is unloaded. Cc: lenb@kernel.org Reported-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com> Signed-off-by: Alex Chiang <achiang@hp.com> --- drivers/acpi/pci_slot.c | 5 +++++ 1 files changed, 5 insertions(+), 0 deletions(-) -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html