[PATCH v2 2/2] gpiolib: use kstrdup_const() for gpio_device label

From: Bartosz Golaszewski
Date: Thu Dec 14 2017 - 09:29:38 EST


Users often pass a pointer to a static string to gpiochip_add_data()
family of functions. Avoid unnecessary memory allocations with the
provided helper routine.

While at it: use a ternary operator instead of an if else for brevity.

Signed-off-by: Bartosz Golaszewski <brgl@xxxxxxxx>
---
drivers/gpio/gpiolib.c | 9 +++------
1 file changed, 3 insertions(+), 6 deletions(-)

diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index 56eec094184c..e9ec44ffaaaf 100644
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -1062,7 +1062,7 @@ static void gpiodevice_release(struct device *dev)

list_del(&gdev->list);
ida_simple_remove(&gpio_ida, gdev->id);
- kfree(gdev->label);
+ kfree_const(gdev->label);
kfree(gdev->descs);
kfree(gdev);
}
@@ -1170,10 +1170,7 @@ int gpiochip_add_data_with_key(struct gpio_chip *chip, void *data,
goto err_free_descs;
}

- if (chip->label)
- gdev->label = kstrdup(chip->label, GFP_KERNEL);
- else
- gdev->label = kstrdup("unknown", GFP_KERNEL);
+ gdev->label = kstrdup_const(chip->label ?: "unknown", GFP_KERNEL);
if (!gdev->label) {
status = -ENOMEM;
goto err_free_descs;
@@ -1294,7 +1291,7 @@ int gpiochip_add_data_with_key(struct gpio_chip *chip, void *data,
list_del(&gdev->list);
spin_unlock_irqrestore(&gpio_lock, flags);
err_free_label:
- kfree(gdev->label);
+ kfree_const(gdev->label);
err_free_descs:
kfree(gdev->descs);
err_free_gdev:
--
2.15.1