ACPI: bus: Ensure that notify handlers are not running after removal

[ Upstream commit faae443738c6f0dac9b0d3d11d108f6911a989a9 ]

Currently, acpi_device_remove_notify_handler() may return while the
notify handler being removed is still running which may allow the
module holding that handler to be torn down prematurely.

Address this issue by making acpi_device_remove_notify_handler() wait
for the handling of all the ACPI events in progress to complete before
returning.

Fixes: 5894b0c46e49 ("ACPI / scan: Move bus operations and notification routines to bus.c")
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/acpi/bus.c b/drivers/acpi/bus.c
index 3b6146b..a16b7de 100644 (file)
--- a/drivers/acpi/bus.c
+++ b/drivers/acpi/bus.c
@@ -586,6 +586,7 @@ static void acpi_device_remove_notify_handler(struct acpi_device *device,
                acpi_remove_notify_handler(device->handle, type,
                                           acpi_notify_device);
        }
+       acpi_os_wait_events_complete();
 }
 
 /* Handle events targeting \_SB device (at present only graceful shutdown) */