From: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
ACPI scan handlers should always be attached to struct acpi_device
objects before any ACPI drivers, but there is a window during which
a driver may be attached to a struct acpi_device before checking if
there is a matching scan handler. Namely, that will happen if an
ACPI driver module is loaded during acpi_bus_scan() right after
the first namespace walk is complete and before the given device
is processed by the second namespace walk.
To prevent that from happening, set the match_driver flags of
struct acpi_device objects right before running device_attach()
for them in acpi_bus_device_attach().
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
---
drivers/acpi/scan.c | 9 ++++++---
1 file changed, 6 insertions(+), 3 deletions(-)
Index: linux-pm/drivers/acpi/scan.c
===================================================================
--- linux-pm.orig/drivers/acpi/scan.c
+++ linux-pm/drivers/acpi/scan.c
@@ -1676,7 +1676,6 @@ void acpi_init_device_object(struct acpi
void acpi_device_add_finalize(struct acpi_device *device)
{
- device->flags.match_driver = true;
dev_set_uevent_suppress(&device->dev, false);
kobject_uevent(&device->dev.kobj, KOBJ_ADD);
}
@@ -1915,8 +1914,12 @@ static acpi_status acpi_bus_device_attac
return AE_OK;
ret = acpi_scan_attach_handler(device);
- if (ret)
- return ret > 0 ? AE_OK : AE_CTRL_DEPTH;
+ if (ret < 0)
+ return AE_CTRL_DEPTH;
+
+ device->flags.match_driver = true;
+ if (ret > 0)
+ return AE_OK;
ret = device_attach(&device->dev);
return ret >= 0 ? AE_OK : AE_CTRL_DEPTH;
--
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