Re: [PATCH 1/8] ALSA: control: change type from long due to the definition of sizeof operator

[Takashi Iwai <tiwai@suse.de>]

At Wed, 11 Feb 2015 19:37:25 +0900,
Takashi Sakamoto wrote:
> 
> The sizeof() operator returns 'unsigned' value, while it's assigned to 'long'.

The type of sizeof() is size_t, which is unsigned long on Linux.
(Imagine the return value of sizeof() for an array over 4GB.)


Takashi

> And in this case, the value is not so large.
>
> This commit change the type of assigned value to 'unsigned int'. Additonally,
> rename local variable assigned to the value.
> 
> Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
> ---
>  sound/core/control.c | 20 ++++++++++----------
>  1 file changed, 10 insertions(+), 10 deletions(-)
> 
> diff --git a/sound/core/control.c b/sound/core/control.c
> index 35324a8..ea49abc 100644
> --- a/sound/core/control.c
> +++ b/sound/core/control.c
> @@ -1007,7 +1007,7 @@ struct user_element {
>  	struct snd_ctl_elem_info info;
>  	struct snd_card *card;
>  	void *elem_data;		/* element data */
> -	unsigned long elem_data_size;	/* size of element data in bytes */
> +	unsigned int elem_data_size;	/* size of element data in bytes */
>  	void *tlv_data;			/* TLV data */
>  	unsigned long tlv_data_size;	/* TLV data size */
>  	void *priv_data;		/* private data (like strings for enumerated type) */
> @@ -1164,7 +1164,7 @@ static int snd_ctl_elem_add(struct snd_ctl_file *file,
>  	struct snd_card *card = file->card;
>  	struct snd_kcontrol kctl, *_kctl;
>  	unsigned int access;
> -	long private_size;
> +	unsigned int elem_data_size;
>  	struct user_element *ue;
>  	int idx, err;
>  
> @@ -1204,42 +1204,42 @@ static int snd_ctl_elem_add(struct snd_ctl_file *file,
>  	switch (info->type) {
>  	case SNDRV_CTL_ELEM_TYPE_BOOLEAN:
>  	case SNDRV_CTL_ELEM_TYPE_INTEGER:
> -		private_size = sizeof(long);
> +		elem_data_size = sizeof(long);
>  		if (info->count > 128)
>  			return -EINVAL;
>  		break;
>  	case SNDRV_CTL_ELEM_TYPE_INTEGER64:
> -		private_size = sizeof(long long);
> +		elem_data_size = sizeof(long long);
>  		if (info->count > 64)
>  			return -EINVAL;
>  		break;
>  	case SNDRV_CTL_ELEM_TYPE_ENUMERATED:
> -		private_size = sizeof(unsigned int);
> +		elem_data_size = sizeof(unsigned int);
>  		if (info->count > 128 || info->value.enumerated.items == 0)
>  			return -EINVAL;
>  		break;
>  	case SNDRV_CTL_ELEM_TYPE_BYTES:
> -		private_size = sizeof(unsigned char);
> +		elem_data_size = sizeof(unsigned char);
>  		if (info->count > 512)
>  			return -EINVAL;
>  		break;
>  	case SNDRV_CTL_ELEM_TYPE_IEC958:
> -		private_size = sizeof(struct snd_aes_iec958);
> +		elem_data_size = sizeof(struct snd_aes_iec958);
>  		if (info->count != 1)
>  			return -EINVAL;
>  		break;
>  	default:
>  		return -EINVAL;
>  	}
> -	private_size *= info->count;
> -	ue = kzalloc(sizeof(struct user_element) + private_size, GFP_KERNEL);
> +	elem_data_size *= info->count;
> +	ue = kzalloc(sizeof(struct user_element) + elem_data_size, GFP_KERNEL);
>  	if (ue == NULL)
>  		return -ENOMEM;
>  	ue->card = card;
>  	ue->info = *info;
>  	ue->info.access = 0;
>  	ue->elem_data = (char *)ue + sizeof(*ue);
> -	ue->elem_data_size = private_size;
> +	ue->elem_data_size = elem_data_size;
>  	if (ue->info.type == SNDRV_CTL_ELEM_TYPE_ENUMERATED) {
>  		err = snd_ctl_elem_init_enum_names(ue);
>  		if (err < 0) {
> -- 
> 2.1.0
>