On 9/16/22 9:36 AM, Wang Yufen wrote:
> Move snprintf and len check to common helper pathname_concat() to make the
> code simpler.
>
> Signed-off-by: Wang Yufen <[email protected]>
> ---
> tools/lib/bpf/libbpf.c | 76 +++++++++++++++++++-------------------------------
> 1 file changed, 29 insertions(+), 47 deletions(-)
>
> diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
> index 3ad1392..7ab977c 100644
> --- a/tools/lib/bpf/libbpf.c
> +++ b/tools/lib/bpf/libbpf.c
> @@ -2096,19 +2096,30 @@ static bool get_map_field_int(const char *map_name, const struct btf *btf,
> return true;
> }
>
> +static int pathname_concat(const char *path, const char *name, char *buf)
> +{
> + int len;
> +
> + len = snprintf(buf, PATH_MAX, "%s/%s", path, name);
> + if (len < 0)
> + return -EINVAL;
> + if (len >= PATH_MAX)
> + return -ENAMETOOLONG;
> +
> + return 0;
> +}
> +
> static int build_map_pin_path(struct bpf_map *map, const char *path)
> {
> char buf[PATH_MAX];
> - int len;
> + int err;
>
> if (!path)
> path = "/sys/fs/bpf";
>
> - len = snprintf(buf, PATH_MAX, "%s/%s", path, bpf_map__name(map));
> - if (len < 0)
> - return -EINVAL;
> - else if (len >= PATH_MAX)
> - return -ENAMETOOLONG;
> + err = pathname_concat(path, bpf_map__name(map), buf);
Small nit, but would be good to not make the assumption that buf is always
PATH_MAX so lets add size_t len to pathname_concat().
> + if (err)
> + return err;
>
> return bpf_map__set_pin_path(map, buf);
> }