On Wed, Apr 30, 2025 at 5:03 AM Anton Protopopov
<a.s.protopopov@xxxxxxxxx> wrote:
>
> Return values of the linker_append_sec_data() and the
> linker_append_elf_relos() functions are propagated all the
> way up to users of libbpf API. In some error cases these
> functions return -1 which will be seen as -EPERM from user's
> point of view. Instead, return a more reasonable -EINVAL.
>
> Fixes: faf6ed321cf6 ("libbpf: Add BPF static linker APIs")
> Signed-off-by: Anton Protopopov <a.s.protopopov@xxxxxxxxx>
> ---
> tools/lib/bpf/linker.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/tools/lib/bpf/linker.c b/tools/lib/bpf/linker.c
> index 56f5068e2eba..a469e5d4fee7 100644
> --- a/tools/lib/bpf/linker.c
> +++ b/tools/lib/bpf/linker.c
> @@ -1376,7 +1376,7 @@ static int linker_append_sec_data(struct bpf_linker *linker, struct src_obj *obj
> } else {
> if (!secs_match(dst_sec, src_sec)) {
> pr_warn("ELF sections %s are incompatible\n", src_sec->sec_name);
> - return -1;
> + return -EINVAL;
> }
>
> /* "license" and "version" sections are deduped */
> @@ -2223,7 +2223,7 @@ static int linker_append_elf_relos(struct bpf_linker *linker, struct src_obj *ob
> }
> } else if (!secs_match(dst_sec, src_sec)) {
> pr_warn("sections %s are not compatible\n", src_sec->sec_name);
> - return -1;
> + return -EINVAL;
doh, not sure how that slipped through, thanks for the fix! I applied
it to bpf-next.
BTW, if you would be so kind, I think we have a similar issue with
validate_nla() in nlattr.c, where -1 can be eventually returned as
user-visible error code, it would be nice to fix this up like you did
with linker APIs, thanks!
> }
>
> /* shdr->sh_link points to SYMTAB */
> --
> 2.34.1
>
