From: Ronald Tschalär ronald@innovation.ch
[ Upstream commit 757c968c442397f1249bb775a7c8c03842e3e0c7 ]
There was a small race when removing the sbshc module where smbus_alarm() had queued acpi_smbus_callback() for deferred execution but it hadn't been run yet, so that when it did run hc had been freed and the module unloaded, resulting in an invalid paging request.
A similar race existed when removing the sbs module with regards to acpi_sbs_callback() (which is called from acpi_smbus_callback()).
We therefore need to ensure no callbacks are pending or executing before the cleanups are done and the modules are removed.
Signed-off-by: Ronald Tschalär ronald@innovation.ch Signed-off-by: Rafael J. Wysocki rafael.j.wysocki@intel.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/acpi/osl.c | 1 + drivers/acpi/sbshc.c | 2 ++ 2 files changed, 3 insertions(+)
diff --git a/drivers/acpi/osl.c b/drivers/acpi/osl.c index 191e86c62037a..9da7e7d874bd8 100644 --- a/drivers/acpi/osl.c +++ b/drivers/acpi/osl.c @@ -1116,6 +1116,7 @@ void acpi_os_wait_events_complete(void) flush_workqueue(kacpid_wq); flush_workqueue(kacpi_notify_wq); } +EXPORT_SYMBOL(acpi_os_wait_events_complete);
struct acpi_hp_work { struct work_struct work; diff --git a/drivers/acpi/sbshc.c b/drivers/acpi/sbshc.c index 7a3431018e0ab..5008ead4609a4 100644 --- a/drivers/acpi/sbshc.c +++ b/drivers/acpi/sbshc.c @@ -196,6 +196,7 @@ int acpi_smbus_unregister_callback(struct acpi_smb_hc *hc) hc->callback = NULL; hc->context = NULL; mutex_unlock(&hc->lock); + acpi_os_wait_events_complete(); return 0; }
@@ -292,6 +293,7 @@ static int acpi_smbus_hc_remove(struct acpi_device *device)
hc = acpi_driver_data(device); acpi_ec_remove_query_handler(hc->ec, hc->query_bit); + acpi_os_wait_events_complete(); kfree(hc); device->driver_data = NULL; return 0;