[LEDE-DEV] [PATCH fstools] libfstools: Check return values for fread and system

[John Crispin]

On 03/12/2016 18:32, Florian Fainelli wrote:
> libfstools/rootdisk.c: In function 'rootdisk_volume_identify':
> libfstools/rootdisk.c:172:7: error: ignoring return value of 'fread', declared with attribute warn_unused_result [-Werror=unused-result]
>   fread(&magic, sizeof(magic), 1, f);
>        ^
> libfstools/rootdisk.c:179:7: error: ignoring return value of 'fread', declared with attribute warn_unused_result [-Werror=unused-result]
>   fread(&magic, sizeof(magic), 1, f);
>        ^
> libfstools/rootdisk.c: In function 'rootdisk_volume_init':
> libfstools/rootdisk.c:268:9: error: ignoring return value of 'system', declared with attribute warn_unused_result [-Werror=unused-result]
>    system(str);
>          ^
> cc1: all warnings being treated as errors
> 
> Signed-off-by: Florian Fainelli <f.fainelli at gmail.com>
> ---
>  libfstools/rootdisk.c | 14 ++++++++++----
>  1 file changed, 10 insertions(+), 4 deletions(-)
> 
> diff --git a/libfstools/rootdisk.c b/libfstools/rootdisk.c
> index d4ff201bf926..b85bcedd98b7 100644
> --- a/libfstools/rootdisk.c
> +++ b/libfstools/rootdisk.c
> @@ -162,6 +162,7 @@ static int rootdisk_volume_identify(struct volume *v)
>  	struct rootdev_volume *p = container_of(v, struct rootdev_volume, v);
>  	int ret = FS_NONE;
>  	uint32_t magic = 0;
> +	size_t n;
>  	FILE *f;
>  
>  	f = fopen(rootdev, "r");
> @@ -169,14 +170,18 @@ static int rootdisk_volume_identify(struct volume *v)
>  		return ret;
>  
>  	fseeko(f, p->offset + 0x400, SEEK_SET);
> -	fread(&magic, sizeof(magic), 1, f);
> +	n = fread(&magic, sizeof(magic), 1, f);
> +	if (n != sizeof(magic))
> +		return -1;
>  
>  	if (magic == cpu_to_le32(0xF2F52010))
>  		ret = FS_F2FS;
>  
>  	magic = 0;
>  	fseeko(f, p->offset + 0x438, SEEK_SET);
> -	fread(&magic, sizeof(magic), 1, f);
> +	n = fread(&magic, sizeof(magic), 1, f);
> +	if (n != sizeof(magic))
> +		return -1;

same issue as witht e uclient patch here i think

	John

>  	if ((le32_to_cpu(magic) & 0xffff) == 0xef53)
>  		ret = FS_EXT4;
>  
> @@ -251,6 +256,7 @@ static int rootdisk_volume_init(struct volume *v)
>  {
>  	struct rootdev_volume *p = container_of(v, struct rootdev_volume, v);
>  	char str[128];
> +	int ret = 0;
>  
>  	if (!p->loop_name[0] && rootdisk_create_loop(p) != 0)
>  		return -1;
> @@ -265,12 +271,12 @@ static int rootdisk_volume_init(struct volume *v)
>  			snprintf(str, sizeof(str), "mkfs.f2fs -l rootfs_data %s", v->blk);
>  		else
>  			snprintf(str, sizeof(str), "mkfs.ext4 -L rootfs_data %s", v->blk);
> -		system(str);
> +		ret = system(str);
>  		break;
>  	default:
>  		break;
>  	}
> -	return 0;
> +	return ret;
>  }
>  
>  static struct driver rootdisk_driver = {
>