5.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Armin Wolf <W_Armin@xxxxxx> [ Upstream commit 86309cbed26139e1caae7629dcca1027d9a28e75 ] Move the conditional locking from __battery_hook_unregister() into battery_hook_unregister() and rename the low-level function to simplify the locking during battery hook removal. Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@xxxxxxxxxxxxxxx> Reviewed-by: Pali Rohár <pali@xxxxxxxxxx> Signed-off-by: Armin Wolf <W_Armin@xxxxxx> Link: https://patch.msgid.link/20241001212835.341788-2-W_Armin@xxxxxx Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx> Stable-dep-of: 76959aff14a0 ("ACPI: battery: Fix possible crash when unregistering a battery hook") Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- drivers/acpi/battery.c | 18 +++++++++--------- 1 file changed, 9 insertions(+), 9 deletions(-) diff --git a/drivers/acpi/battery.c b/drivers/acpi/battery.c index af78f76a28729..6c45d183213ed 100644 --- a/drivers/acpi/battery.c +++ b/drivers/acpi/battery.c @@ -706,27 +706,27 @@ static LIST_HEAD(acpi_battery_list); static LIST_HEAD(battery_hook_list); static DEFINE_MUTEX(hook_mutex); -static void __battery_hook_unregister(struct acpi_battery_hook *hook, int lock) +static void battery_hook_unregister_unlocked(struct acpi_battery_hook *hook) { struct acpi_battery *battery; + /* * In order to remove a hook, we first need to * de-register all the batteries that are registered. */ - if (lock) - mutex_lock(&hook_mutex); list_for_each_entry(battery, &acpi_battery_list, list) { hook->remove_battery(battery->bat); } list_del(&hook->list); - if (lock) - mutex_unlock(&hook_mutex); + pr_info("extension unregistered: %s\n", hook->name); } void battery_hook_unregister(struct acpi_battery_hook *hook) { - __battery_hook_unregister(hook, 1); + mutex_lock(&hook_mutex); + battery_hook_unregister_unlocked(hook); + mutex_unlock(&hook_mutex); } EXPORT_SYMBOL_GPL(battery_hook_unregister); @@ -752,7 +752,7 @@ void battery_hook_register(struct acpi_battery_hook *hook) * hooks. */ pr_err("extension failed to load: %s", hook->name); - __battery_hook_unregister(hook, 0); + battery_hook_unregister_unlocked(hook); goto end; } } @@ -789,7 +789,7 @@ static void battery_hook_add_battery(struct acpi_battery *battery) */ pr_err("error in extension, unloading: %s", hook_node->name); - __battery_hook_unregister(hook_node, 0); + battery_hook_unregister_unlocked(hook_node); } } mutex_unlock(&hook_mutex); @@ -822,7 +822,7 @@ static void __exit battery_hook_exit(void) * need to remove the hooks. */ list_for_each_entry_safe(hook, ptr, &battery_hook_list, list) { - __battery_hook_unregister(hook, 1); + battery_hook_unregister(hook); } mutex_destroy(&hook_mutex); } -- 2.43.0
