[PATCH] HID: input: use __free(kfree) to clean up temporary buffers

[PATCH] HID: input: use __free(kfree) to clean up temporary buffers

[Dmitry Torokhov]

The __free() cleanup automatically releases given resource when leaving
the scope, so use it to make the code less cluttered with error
handling.

Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
---
 drivers/hid/hid-input.c | 15 ++++-----------
 1 file changed, 4 insertions(+), 11 deletions(-)

diff --git a/drivers/hid/hid-input.c b/drivers/hid/hid-input.c
index 2633fcd8f910..9b2d7795c621 100644
--- a/drivers/hid/hid-input.c
+++ b/drivers/hid/hid-input.c
@@ -432,23 +432,18 @@ static int hidinput_scale_battery_capacity(struct hid_device *dev,
 
 static int hidinput_query_battery_capacity(struct hid_device *dev)
 {
-	u8 *buf;
 	int ret;
 
-	buf = kmalloc(4, GFP_KERNEL);
+	u8 *buf __free(kfree) = kmalloc(4, GFP_KERNEL);
 	if (!buf)
 		return -ENOMEM;
 
 	ret = hid_hw_raw_request(dev, dev->battery_report_id, buf, 4,
 				 dev->battery_report_type, HID_REQ_GET_REPORT);
-	if (ret < 2) {
-		kfree(buf);
+	if (ret < 2)
 		return -ENODATA;
-	}
 
-	ret = hidinput_scale_battery_capacity(dev, buf[1]);
-	kfree(buf);
-	return ret;
+	return hidinput_scale_battery_capacity(dev, buf[1]);
 }
 
 static int hidinput_get_battery_property(struct power_supply *psy,
@@ -1832,7 +1827,6 @@ static void hidinput_led_worker(struct work_struct *work)
 	struct hid_report *report;
 	int ret;
 	u32 len;
-	__u8 *buf;
 
 	field = hidinput_get_led_field(hid);
 	if (!field)
@@ -1859,7 +1853,7 @@ static void hidinput_led_worker(struct work_struct *work)
 
 	/* fall back to generic raw-output-report */
 	len = hid_report_len(report);
-	buf = hid_alloc_report_buf(report, GFP_KERNEL);
+	u8 *buf __free(kfree) = hid_alloc_report_buf(report, GFP_KERNEL);
 	if (!buf)
 		return;
 
@@ -1869,7 +1863,6 @@ static void hidinput_led_worker(struct work_struct *work)
 	if (ret == -ENOSYS)
 		hid_hw_raw_request(hid, report->id, buf, len, HID_OUTPUT_REPORT,
 				HID_REQ_SET_REPORT);
-	kfree(buf);
 }
 
 static int hidinput_input_event(struct input_dev *dev, unsigned int type,
-- 
2.53.0.473.g4a7958ca14-goog


-- 
Dmitry

Re: [PATCH] HID: input: use __free(kfree) to clean up temporary buffers

[Jiri Kosina]

On Sat, 28 Feb 2026, Dmitry Torokhov wrote:

> The __free() cleanup automatically releases given resource when leaving
> the scope, so use it to make the code less cluttered with error
> handling.
> 
> Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

Applied to hid.git#for-7.1/core. Thanks,

-- 
Jiri Kosina
SUSE Labs