Skip to contentSkip to conversation

Input: psmouse-smbus - use guard notation when acquiring mutex

PATCH In review Dmitry Torokhov 2 participants 3 messages Aug 25, 2024 – Oct 3, 2024

Subsystems (2)
lore
Share & tools
lore

Dmitry Torokhov

author maintainer
#0 lore raw

PATCH 1/1 Input: psmouse-smbus - use guard notation when acquiring mutex

This makes the code more compact and error handling more robust by ensuring that mutexes are released in all code paths when control leaves critical section.

---
 drivers/input/mouse/psmouse-smbus.c | 28 ++++++++++------------------
 1 file changed, 10 insertions(+), 18 deletions(-)
drivers/input/mouse/psmouse-smbus.c +10 -18
index 2a2459b1b4f2..93420f07b7d0 100644
@@ -35,7 +35,7 @@ static void psmouse_smbus_check_adapter(struct i2c_adapter *adapter)
 	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_HOST_NOTIFY))
 		return;
 
-	mutex_lock(&psmouse_smbus_mutex);
+	guard(mutex)(&psmouse_smbus_mutex);
 
 	list_for_each_entry(smbdev, &psmouse_smbus_list, node) {
 		if (smbdev->dead)
@@ -55,15 +55,13 @@ static void psmouse_smbus_check_adapter(struct i2c_adapter *adapter)
 			    "SMBus candidate adapter appeared, triggering rescan\n");
 		serio_rescan(smbdev->psmouse->ps2dev.serio);
 	}
-
-	mutex_unlock(&psmouse_smbus_mutex);
 }
 
 static void psmouse_smbus_detach_i2c_client(struct i2c_client *client)
 {
 	struct psmouse_smbus_dev *smbdev, *tmp;
 
-	mutex_lock(&psmouse_smbus_mutex);
+	guard(mutex)(&psmouse_smbus_mutex);
 
 	list_for_each_entry_safe(smbdev, tmp, &psmouse_smbus_list, node) {
 		if (smbdev->client != client)
@@ -85,8 +83,6 @@ static void psmouse_smbus_detach_i2c_client(struct i2c_client *client)
 			kfree(smbdev);
 		}
 	}
-
-	mutex_unlock(&psmouse_smbus_mutex);
 }
 
 static int psmouse_smbus_notifier_call(struct notifier_block *nb,
@@ -171,7 +167,7 @@ static void psmouse_smbus_disconnect(struct psmouse *psmouse)
 {
 	struct psmouse_smbus_dev *smbdev = psmouse->private;
 
-	mutex_lock(&psmouse_smbus_mutex);
+	guard(mutex)(&psmouse_smbus_mutex);
 
 	if (smbdev->dead) {
 		list_del(&smbdev->node);
@@ -186,8 +182,6 @@ static void psmouse_smbus_disconnect(struct psmouse *psmouse)
 		psmouse_smbus_schedule_remove(smbdev->client);
 	}
 
-	mutex_unlock(&psmouse_smbus_mutex);
-
 	psmouse->private = NULL;
 }
 
@@ -219,7 +213,7 @@ void psmouse_smbus_cleanup(struct psmouse *psmouse)
 {
 	struct psmouse_smbus_dev *smbdev, *tmp;
 
-	mutex_lock(&psmouse_smbus_mutex);
+	guard(mutex)(&psmouse_smbus_mutex);
 
 	list_for_each_entry_safe(smbdev, tmp, &psmouse_smbus_list, node) {
 		if (psmouse == smbdev->psmouse) {
@@ -227,8 +221,6 @@ void psmouse_smbus_cleanup(struct psmouse *psmouse)
 			kfree(smbdev);
 		}
 	}
-
-	mutex_unlock(&psmouse_smbus_mutex);
 }
 
 int psmouse_smbus_init(struct psmouse *psmouse,
@@ -267,9 +259,9 @@ int psmouse_smbus_init(struct psmouse *psmouse,
 	psmouse->disconnect = psmouse_smbus_disconnect;
 	psmouse->resync_time = 0;
 
-	mutex_lock(&psmouse_smbus_mutex);
-	list_add_tail(&smbdev->node, &psmouse_smbus_list);
-	mutex_unlock(&psmouse_smbus_mutex);
+	scoped_guard(mutex, &psmouse_smbus_mutex) {
+		list_add_tail(&smbdev->node, &psmouse_smbus_list);
+	}
 
 	/* Bind to already existing adapters right away */
 	error = i2c_for_each_dev(smbdev, psmouse_smbus_create_companion);
@@ -293,9 +285,9 @@ int psmouse_smbus_init(struct psmouse *psmouse,
 	smbdev->board.platform_data = NULL;
 
 	if (error < 0 || !leave_breadcrumbs) {
-		mutex_lock(&psmouse_smbus_mutex);
-		list_del(&smbdev->node);
-		mutex_unlock(&psmouse_smbus_mutex);
+		scoped_guard(mutex, &psmouse_smbus_mutex) {
+			list_del(&smbdev->node);
+		}
 
 		kfree(smbdev);
 	}
Signature · 5 lines
2.46.0.295.g3b9ea8a38a-goog


-- 
Dmitry