Re: [PATCH] libbpf: Initialize st_ops->tname with strdup()

[Christophe JAILLET <christophe.jaillet@wanadoo.fr>]

Le 21/08/2024 à 08:46, Soma Nakata a écrit :
> `tname` is returned by `btf__name_by_offset()` as well as `var_name`,
> and these addresses point to strings in the btf. Since their locations
> may change while loading the bpf program, using `strdup()` ensures
> `tname` is safely stored.
> 
> Signed-off-by: Soma Nakata <soma.nakata01@gmail.com>
> ---
>   tools/lib/bpf/libbpf.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
> index a3be6f8fac09..ece1f1af2cd4 100644
> --- a/tools/lib/bpf/libbpf.c
> +++ b/tools/lib/bpf/libbpf.c
> @@ -1423,7 +1423,7 @@ static int init_struct_ops_maps(struct bpf_object *obj, const char *sec_name,
>   		memcpy(st_ops->data,
>   		       data->d_buf + vsi->offset,
>   		       type->size);
> -		st_ops->tname = tname;
> +		st_ops->tname = strdup(tname);

Hi,

Should a NULL check be added (as done a few lines above for the 
[cm]alloc()) and bpf_map__destroy() updated with a 
zfree(&map->st_ops->tname) ?

CJ

>   		st_ops->type = type;
>   		st_ops->type_id = type_id;
>