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

From: Bartosz Golaszewski
Date: Thu Dec 14 2017 - 09:31:31 EST


2017-12-13 20:44 GMT+01:00 Joe Perches <joe@xxxxxxxxxxx>:
> On Wed, 2017-12-13 at 12:25 +0100, Bartosz Golaszewski wrote:
>> 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.
> []
>> diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
> []
>> @@ -1171,9 +1171,9 @@ int gpiochip_add_data_with_key(struct gpio_chip *chip, void *data,
>> }
>>
>> if (chip->label)
>> - gdev->label = kstrdup(chip->label, GFP_KERNEL);
>> + gdev->label = kstrdup_const(chip->label, GFP_KERNEL);
>> else
>> - gdev->label = kstrdup("unknown", GFP_KERNEL);
>> + gdev->label = kstrdup_const("unknown", GFP_KERNEL);
>
> A plain ?: would be more intelligible
> and a bit smaller object code too.
>
> ie:
> gdev->label = kstrdup_const(chip->label ?: "unknown", GFP_KERNEL);
>
>> if (!gdev->label) {
>> status = -ENOMEM;
>> goto err_free_descs;
>

Good point. Sent v2.

Thanks,
Bartosz