Re: [PATCH] ACPIPHP: fix device destroying order issue in handlingdock notification

From: Alexander E. Patrakov
Date: Tue Jun 11 2013 - 08:15:23 EST


2013/6/11 Jiang Liu <liuj97@xxxxxxxxx>:
> Current ACPI glue logic expects that physical devices are destroyed
> before destroying companion ACPI devices, otherwise it will break the
> ACPI unbind logic and cause following warning messages:
> [ 185.026073] usb usb5: Oops, 'acpi_handle' corrupt
> [ 185.035150] pci 0000:1b:00.0: Oops, 'acpi_handle' corrupt
> [ 185.035515] pci 0000:18:02.0: Oops, 'acpi_handle' corrupt
> [ 180.013656] port1: Oops, 'acpi_handle' corrupt
> Please refer to https://bugzilla.kernel.org/attachment.cgi?id=104321
> for full log message.

This causes lockdep spew, see
https://bugzilla.kernel.org/attachment.cgi?id=104411

So, probably a NAK.

> Above warning messages are caused by following scenario:
> 1) acpi_dock_notifier_call() queues a task (T1) onto kacpi_hotplug_wq
> 2) kacpi_hotplug_wq handles T1, which invokes acpi_dock_deferred_cb()
> ->dock_notify()-> handle_eject_request()->hotplug_dock_devices()
> 3) hotplug_dock_devices() first invokes registered hotplug callbacks to
> destroy physical devices, then destroys all affected ACPI devices.
> Everything seems perfect until now. But the acpiphp dock notification
> handler will queue another task (T2) onto kacpi_hotplug_wq to really
> destroy affected physical devices.
> 4) kacpi_hotplug_wq finishes T1, and all affected ACPI devices have
> been destroyed.
> 5) kacpi_hotplug_wq handles T2, which destroys all affected physical
> devices.
>
> So it breaks the ACPI glue expection because ACPI devices are destroyed
> in step 3 and physical devices are destroyed in step 5.
>
> Signed-off-by: Jiang Liu <jiang.liu@xxxxxxxxxx>
> Cc: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
> Cc: Yinghai Lu <yinghai@xxxxxxxxxx>
> Cc: "Rafael J. Wysocki" <rafael.j.wysocki@xxxxxxxxx>
> Cc: linux-pci@xxxxxxxxxxxxxxx
> Cc: linux-kernel@xxxxxxxxxxxxxxx
> ---
> Hi all,
> We are trying to solve bug https://bugzilla.kernel.org/show_bug.cgi?id=59501
> And seems there are multiple bugs behind bug 59501. This draft patch tries to
> fix one of those issues. I will send out form patchset once all issue have been
> resolved.
>
> Regards!
> Gerry
> ---
> drivers/pci/hotplug/acpiphp_glue.c | 31 +++++++++++++++++++------------
> 1 file changed, 19 insertions(+), 12 deletions(-)
>
> diff --git a/drivers/pci/hotplug/acpiphp_glue.c b/drivers/pci/hotplug/acpiphp_glue.c
> index 716aa93..b132aca 100644
> --- a/drivers/pci/hotplug/acpiphp_glue.c
> +++ b/drivers/pci/hotplug/acpiphp_glue.c
> @@ -61,7 +61,10 @@ static DEFINE_MUTEX(bridge_mutex);
> static void handle_hotplug_event_bridge (acpi_handle, u32, void *);
> static void acpiphp_sanitize_bus(struct pci_bus *bus);
> static void acpiphp_set_hpp_values(struct pci_bus *bus);
> -static void handle_hotplug_event_func(acpi_handle handle, u32 type, void *context);
> +static void __handle_hotplug_event_func(acpi_handle handle, u32 type,
> + void *context);
> +static void handle_hotplug_event_func(acpi_handle handle, u32 type,
> + void *context);
> static void free_bridge(struct kref *kref);
>
> /* callback routine to check for the existence of a pci dock device */
> @@ -147,7 +150,7 @@ static int post_dock_fixups(struct notifier_block *nb, unsigned long val,
>
>
> static const struct acpi_dock_ops acpiphp_dock_ops = {
> - .handler = handle_hotplug_event_func,
> + .handler = __handle_hotplug_event_func,
> };
>
> /* Check whether the PCI device is managed by native PCIe hotplug driver */
> @@ -1065,20 +1068,13 @@ static void handle_hotplug_event_bridge(acpi_handle handle, u32 type,
> alloc_acpi_hp_work(handle, type, context, _handle_hotplug_event_bridge);
> }
>
> -static void _handle_hotplug_event_func(struct work_struct *work)
> +static void __handle_hotplug_event_func(acpi_handle handle, u32 type,
> + void *context)
> {
> - struct acpiphp_func *func;
> + struct acpiphp_func *func = context;
> char objname[64];
> struct acpi_buffer buffer = { .length = sizeof(objname),
> .pointer = objname };
> - struct acpi_hp_work *hp_work;
> - acpi_handle handle;
> - u32 type;
> -
> - hp_work = container_of(work, struct acpi_hp_work, work);
> - handle = hp_work->handle;
> - type = hp_work->type;
> - func = (struct acpiphp_func *)hp_work->context;
>
> acpi_scan_lock_acquire();
>
> @@ -1115,6 +1111,17 @@ static void _handle_hotplug_event_func(struct work_struct *work)
> }
>
> acpi_scan_lock_release();
> +}
> +
> +static void _handle_hotplug_event_func(struct work_struct *work)
> +{
> + struct acpiphp_func *func;
> + struct acpi_hp_work *hp_work;
> +
> + hp_work = container_of(work, struct acpi_hp_work, work);
> + func = (struct acpiphp_func *)hp_work->context;
> + __handle_hotplug_event_func(hp_work->handle, hp_work->type,
> + hp_work->context);
> kfree(hp_work); /* allocated in handle_hotplug_event_func */
> put_bridge(func->slot->bridge);
> }
> --
> 1.8.1.2
>



--
Alexander E. Patrakov
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