[PATCH 15/18] HID: logitech-hidpp: use __free(kfree) for temporary allocations
From: Dmitry Torokhov
Date: Mon Nov 09 2026 - 01:17:05 EST
Managing short-lived heap allocations manually with explicit kfree()
calls adds boilerplate cleanup paths and forces callers to hold
temporary return variables across calls.
Convert temporary message and device-name allocations in command helpers
and device initialization paths to use __free(kfree) with no_free_ptr()
ownership transfer where the buffer is returned to callers.
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@xxxxxxxxx>
---
drivers/hid/hid-logitech-hidpp.c | 44 ++++++++++----------------------
1 file changed, 14 insertions(+), 30 deletions(-)
diff --git a/drivers/hid/hid-logitech-hidpp.c b/drivers/hid/hid-logitech-hidpp.c
index bf13e5fbe142..7f5de4caf118 100644
--- a/drivers/hid/hid-logitech-hidpp.c
+++ b/drivers/hid/hid-logitech-hidpp.c
@@ -390,18 +390,15 @@ static int hidpp_send_fap_command_sync(struct hidpp_device *hidpp,
u8 feat_index, u8 funcindex_clientid, u8 *params, int param_count,
struct hidpp_report *response)
{
- struct hidpp_report *message;
- int ret;
-
- if (param_count > sizeof(message->fap.params)) {
+ if (param_count > sizeof_field(struct hidpp_report, fap.params)) {
hid_dbg(hidpp->hid_dev,
"Invalid number of parameters passed to command (%d != %llu)\n",
param_count,
- (unsigned long long) sizeof(message->fap.params));
+ (unsigned long long)sizeof_field(struct hidpp_report, fap.params));
return -EINVAL;
}
- message = kzalloc_obj(struct hidpp_report);
+ struct hidpp_report *message __free(kfree) = kzalloc_obj(*message);
if (!message)
return -ENOMEM;
@@ -413,9 +410,7 @@ static int hidpp_send_fap_command_sync(struct hidpp_device *hidpp,
message->fap.funcindex_clientid = funcindex_clientid | LINUX_KERNEL_SW_ID;
memcpy(&message->fap.params, params, param_count);
- ret = hidpp_send_message_sync(hidpp, message, response);
- kfree(message);
- return ret;
+ return hidpp_send_message_sync(hidpp, message, response);
}
/*
@@ -429,8 +424,7 @@ static int hidpp_send_rap_command_sync(struct hidpp_device *hidpp_dev,
u8 report_id, u8 sub_id, u8 reg_address, u8 *params, int param_count,
struct hidpp_report *response)
{
- struct hidpp_report *message;
- int ret, max_count;
+ int max_count;
/* Send as long report if short reports are not supported. */
if (report_id == REPORT_ID_HIDPP_SHORT &&
@@ -454,7 +448,7 @@ static int hidpp_send_rap_command_sync(struct hidpp_device *hidpp_dev,
if (param_count > max_count)
return -EINVAL;
- message = kzalloc_obj(struct hidpp_report);
+ struct hidpp_report *message __free(kfree) = kzalloc_obj(*message);
if (!message)
return -ENOMEM;
message->report_id = report_id;
@@ -462,9 +456,7 @@ static int hidpp_send_rap_command_sync(struct hidpp_device *hidpp_dev,
message->rap.reg_address = reg_address;
memcpy(&message->rap.params, params, param_count);
- ret = hidpp_send_message_sync(hidpp_dev, message, response);
- kfree(message);
- return ret;
+ return hidpp_send_message_sync(hidpp_dev, message, response);
}
static inline bool hidpp_match_answer(struct hidpp_report *question,
@@ -910,7 +902,6 @@ static int hidpp_unifying_get_serial(struct hidpp_device *hidpp,
static int hidpp_unifying_init(struct hidpp_device *hidpp)
{
struct hid_device *hdev = hidpp->hid_dev;
- const char *name;
u8 serial[HIDPP_SERIAL_LENGTH];
int ret;
@@ -921,14 +912,13 @@ static int hidpp_unifying_init(struct hidpp_device *hidpp)
snprintf(hdev->uniq, sizeof(hdev->uniq), "%4phD", serial);
dbg_hid("HID++ Unifying: Got serial: %s\n", hdev->uniq);
- name = hidpp_unifying_get_name(hidpp);
+ char *name __free(kfree) = hidpp_unifying_get_name(hidpp);
if (!name)
return -EIO;
snprintf(hdev->name, sizeof(hdev->name), "%s", name);
dbg_hid("HID++ Unifying: Got name: %s\n", name);
- kfree(name);
return 0;
}
@@ -1142,7 +1132,6 @@ static char *hidpp_get_device_name(struct hidpp_device *hidpp)
{
u8 feature_index;
u8 __name_length;
- char *name;
unsigned index = 0;
int ret;
@@ -1156,7 +1145,7 @@ static char *hidpp_get_device_name(struct hidpp_device *hidpp)
if (ret)
return NULL;
- name = kzalloc(__name_length + 1, GFP_KERNEL);
+ char *name __free(kfree) = kzalloc(__name_length + 1, GFP_KERNEL);
if (!name)
return NULL;
@@ -1164,17 +1153,15 @@ static char *hidpp_get_device_name(struct hidpp_device *hidpp)
ret = hidpp_devicenametype_get_device_name(hidpp,
feature_index, index, name + index,
__name_length - index);
- if (ret <= 0) {
- kfree(name);
+ if (ret <= 0)
return NULL;
- }
index += ret;
}
/* include the terminating '\0' */
hidpp_prefix_name(&name, __name_length + 1);
- return name;
+ return no_free_ptr(name);
}
/* -------------------------------------------------------------------------- */
@@ -4432,17 +4419,15 @@ static int hidpp_initialize_battery(struct hidpp_device *hidpp)
static void hidpp_non_unifying_init(struct hidpp_device *hidpp)
{
struct hid_device *hdev = hidpp->hid_dev;
- char *name;
/* Bluetooth devices already have their serialnr set */
if (hid_is_usb(hdev))
hidpp_serial_init(hidpp);
- name = hidpp_get_device_name(hidpp);
+ char *name __free(kfree) = hidpp_get_device_name(hidpp);
if (name) {
dbg_hid("HID++: Got name: %s\n", name);
snprintf(hdev->name, sizeof(hdev->name), "%s", name);
- kfree(name);
}
}
@@ -4489,7 +4474,7 @@ static void hidpp_connect_event(struct work_struct *work)
struct hidpp_device *hidpp = container_of(work, struct hidpp_device, work);
struct hid_device *hdev = hidpp->hid_dev;
struct input_dev *input;
- char *name, *devm_name;
+ char *devm_name;
int ret;
/* Get device version to check if it is connected */
@@ -4547,11 +4532,10 @@ static void hidpp_connect_event(struct work_struct *work)
}
if (hidpp->name == hdev->name && hidpp->protocol_major >= 2) {
- name = hidpp_get_device_name(hidpp);
+ char *name __free(kfree) = hidpp_get_device_name(hidpp);
if (name) {
devm_name = devm_kasprintf(&hdev->dev, GFP_KERNEL,
"%s", name);
- kfree(name);
if (!devm_name)
return;
--
2.56.0.506.g506a7eabc5-goog