[PATCH] thermal: core: Save a few bytes of memory when registering a cooling device

From: Christophe JAILLET
Date: Fri Jan 05 2024 - 08:45:37 EST


Some *thermal_cooling_device_register() calls pass a string literal as the
'type' parameter.

So kstrdup_const() can be used instead of kfree() to avoid a memory
allocation in such cases.

Signed-off-by: Christophe JAILLET <christophe.jaillet@xxxxxxxxxx>
---
drivers/thermal/thermal_core.c | 6 +++---
include/linux/thermal.h | 2 +-
2 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/thermal/thermal_core.c b/drivers/thermal/thermal_core.c
index fa88d8707241..d21225ddbf10 100644
--- a/drivers/thermal/thermal_core.c
+++ b/drivers/thermal/thermal_core.c
@@ -846,7 +846,7 @@ static void thermal_release(struct device *dev)
sizeof("cooling_device") - 1)) {
cdev = to_cooling_device(dev);
thermal_cooling_device_destroy_sysfs(cdev);
- kfree(cdev->type);
+ kfree_const(cdev->type);
ida_free(&thermal_cdev_ida, cdev->id);
kfree(cdev);
}
@@ -918,7 +918,7 @@ __thermal_cooling_device_register(struct device_node *np,
cdev->id = ret;
id = ret;

- cdev->type = kstrdup(type ? type : "", GFP_KERNEL);
+ cdev->type = kstrdup_const(type ? type : "", GFP_KERNEL);
if (!cdev->type) {
ret = -ENOMEM;
goto out_ida_remove;
@@ -969,7 +969,7 @@ __thermal_cooling_device_register(struct device_node *np,
out_cooling_dev:
thermal_cooling_device_destroy_sysfs(cdev);
out_cdev_type:
- kfree(cdev->type);
+ kfree_const(cdev->type);
out_ida_remove:
ida_free(&thermal_cdev_ida, id);
out_kfree_cdev:
diff --git a/include/linux/thermal.h b/include/linux/thermal.h
index bf84595a4e86..052c72c0fa17 100644
--- a/include/linux/thermal.h
+++ b/include/linux/thermal.h
@@ -102,7 +102,7 @@ struct thermal_cooling_device_ops {

struct thermal_cooling_device {
int id;
- char *type;
+ const char *type;
unsigned long max_state;
struct device device;
struct device_node *np;
--
2.34.1