Re: [PATCH] acpi: pci_root: fix NULL pointer deref after resume from suspend

Danny Feng
2009-10-09T02:30:06Z

On 10/02/2009 04:05 AM, Alex Chiang wrote:
> Hi Danny,
>
> * Danny Feng<dfeng@redhat.com>:
>> Call Trace:
>> [<ffffffff81254193>] acpi_get_pci_dev+0x106/0x167
>> [<ffffffff8125545a>] acpi_pci_bind+0x1c/0x86
>> [<ffffffff8116230a>] ? sysfs_create_file+0x2a/0x2c
>> [<ffffffff8125141f>] acpi_add_single_object+0x964/0xa0c
>> [<ffffffff812515a7>] acpi_bus_check_add+0xe0/0x138
>> [<ffffffff81251667>] acpi_bus_scan+0x68/0xa0
>> [<ffffffff812516f4>] acpi_bus_add+0x2a/0x2e
>> [<ffffffff81252c59>] hotplug_dock_devices+0x114/0x13e
>> [<ffffffff8125301a>] acpi_dock_deferred_cb+0xbf/0x192
>> [<ffffffff8124d6ca>] acpi_os_execute_deferred+0x29/0x36
>> [<ffffffff8106a244>] worker_thread+0x251/0x347
>> [<ffffffff8106a1ef>] ? worker_thread+0x1fc/0x347
>> [<ffffffff8124d6a1>] ? acpi_os_execute_deferred+0x0/0x36
>> [<ffffffff8106e426>] ? autoremove_wake_function+0x0/0x39
>> [<ffffffff81069ff3>] ? worker_thread+0x0/0x347
>> [<ffffffff8106e0e0>] kthread+0x7f/0x87
>> [<ffffffff81012cea>] child_rip+0xa/0x20
>> [<ffffffff81012650>] ? restore_args+0x0/0x30
>> [<ffffffff8106e061>] ? kthread+0x0/0x87
>> [<ffffffff81012ce0>] ? child_rip+0x0/0x20
>> Code: ff 49 89 fc 41 89 f5 a9 00 ff ff 07 74 11 be 87 00 00 00 48 c7 c7
>> 45 6d 5a 81 e8 f6 2b e3 ff 48 c7 c7 30 ab 68 81 e8 29 77 20 00<49> 8b
>> 5c 24 28 49 83 c4 28 eb 09 44 39 6b 38 74 10 48 89 c3 48
>> RIP [<ffffffff812217e7>] pci_get_slot+0x4c/0x8c
>> RSP<ffff88022ee69aa0>
>> CR2: 0000000000000028
>> ---[ end trace b5a7793bd9db2a4d ]---
>
> Can you please reproduce with this debug patch? I'm guessing that
> we're dying because we have a NULL parent device, but I'm curious
> as to what causes this situation to occur.
I got following call trace at the first boot stage.

Pid: 1, comm: swapper Not tainted 2.6.32-rc2 #16
Call Trace:
[<ffffffff81253538>] register_hotplug_dock_device+0x92/0xf7
[<ffffffff812f1622>] ata_acpi_associate+0x144/0x196
[<ffffffff812dfb29>] ata_host_register+0xc5/0x1fb
[<ffffffff812ee9b1>] ? ata_sff_interrupt+0x0/0x96
[<ffffffff812eca12>] ata_pci_sff_activate_host+0x19b/0x1d1
[<ffffffff8137216e>] ? pcibios_set_master+0x9b/0xa9
[<ffffffff8141d878>] piix_init_one+0x760/0x780
[<ffffffff81220325>] local_pci_probe+0x17/0x1b
[<ffffffff812210fd>] pci_device_probe+0xca/0xfa
[<ffffffff812b93aa>] ? driver_sysfs_add+0x4c/0x71
[<ffffffff812b94f2>] driver_probe_device+0xa2/0x127
[<ffffffff812b95d4>] __driver_attach+0x5d/0x81
[<ffffffff812b9577>] ? __driver_attach+0x0/0x81
[<ffffffff812b8ae9>] bus_for_each_dev+0x59/0x8e
[<ffffffff812b935c>] driver_attach+0x1e/0x20
[<ffffffff812b8fa7>] bus_add_driver+0xb9/0x202
[<ffffffff812b98c7>] driver_register+0x9d/0x10e
[<ffffffff81221343>] __pci_register_driver+0x68/0xd8
[<ffffffff81728e98>] ? piix_init+0x0/0x29
[<ffffffff81728eb1>] piix_init+0x19/0x29
[<ffffffff8100a069>] do_one_initcall+0x5e/0x15e
[<ffffffff816f86c7>] kernel_init+0x170/0x1ca
[<ffffffff81012cea>] child_rip+0xa/0x20
[<ffffffff81012650>] ? restore_args+0x0/0x30
[<ffffffff816f8557>] ? kernel_init+0x0/0x1ca
[<ffffffff81012ce0>] ? child_rip+0x0/0x20
dock_add_hotplug_device adding handle ffff88022f712000

Thanks,
Danny
>
> Thanks.
> /ac
> ---
> diff --git a/drivers/acpi/dock.c b/drivers/acpi/dock.c
> index 7338b6a..4c1b128 100644
> --- a/drivers/acpi/dock.c
> +++ b/drivers/acpi/dock.c
> @@ -126,6 +126,7 @@ add_dock_dependent_device(struct dock_station *ds,
> {
> spin_lock(&ds->dd_lock);
> list_add_tail(&dd->list,&ds->dependent_devices);
> + printk("%s adding handle %p\n", __func__, dd->handle);
> spin_unlock(&ds->dd_lock);
> }
>
> @@ -142,6 +143,8 @@ dock_add_hotplug_device(struct dock_station *ds,
> {
> mutex_lock(&ds->hp_lock);
> list_add_tail(&dd->hotplug_list,&ds->hotplug_devices);
> + dump_stack();
> + printk("%s adding handle %p\n", __func__, dd->handle);
> mutex_unlock(&ds->hp_lock);
> }
>
> @@ -325,14 +328,17 @@ static struct acpi_device * dock_create_acpi_device(acpi_handle handle)
> acpi_handle parent;
> int ret;
>
> + printk("%s handle %p\n", __func__, handle);
> if (acpi_bus_get_device(handle,&device)) {
> /*
> * no device created for this object,
> * so we should create one.
> */
> acpi_get_parent(handle,&parent);
> - if (acpi_bus_get_device(parent,&parent_device))
> + if (acpi_bus_get_device(parent,&parent_device)) {
> parent_device = NULL;
> + printk("%s no parent, setting NULL\n", __func__);
> + }
>
> ret = acpi_bus_add(&device, parent_device, handle,
> ACPI_BUS_TYPE_DEVICE);
> @@ -385,8 +391,10 @@ static void hotplug_dock_devices(struct dock_station *ds, u32 event)
> * First call driver specific hotplug functions
> */
> list_for_each_entry(dd,&ds->hotplug_devices, hotplug_list) {
> - if (dd->ops&& dd->ops->handler)
> + if (dd->ops&& dd->ops->handler) {
> + printk("%s handle %p\n", __func__, dd->handle);
> dd->ops->handler(dd->handle, event, dd->context);
> + }
> }
>
> /*
> @@ -1041,6 +1049,7 @@ static int dock_add(acpi_handle handle)
> ret = -ENOMEM;
> goto dock_add_err_unregister;
> }
> + printk("%s adding self as dependent %p)\n", __func__, dd->handle);
> add_dock_dependent_device(dock_station, dd);
>
> dock_station_count++;
>