On Thu, 19 Jan 2023 at 19:43, Jiri Olsa <jolsa@xxxxxxxxxx> wrote:
>
> We take the BTF reference before we register dtors and we need
> to put it back when it's done.
>
> We probably won't se a problem with kernel BTF, but module BTF
> would stay loaded (because of the extra ref) even when its module
> is removed.
>
> Cc: Kumar Kartikeya Dwivedi <memxor@xxxxxxxxx>
> Fixes: 5ce937d613a4 ("bpf: Populate pairs of btf_id and destructor kfunc in btf")
> Signed-off-by: Jiri Olsa <jolsa@xxxxxxxxxx>
> ---
Thanks for the fix.
Acked-by: Kumar Kartikeya Dwivedi <memxor@xxxxxxxxx>
> kernel/bpf/btf.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/kernel/bpf/btf.c b/kernel/bpf/btf.c
> index f7dd8af06413..b7017cae6fd1 100644
> --- a/kernel/bpf/btf.c
> +++ b/kernel/bpf/btf.c
> @@ -7782,9 +7782,9 @@ int register_btf_id_dtor_kfuncs(const struct btf_id_dtor_kfunc *dtors, u32 add_c
>
> sort(tab->dtors, tab->cnt, sizeof(tab->dtors[0]), btf_id_cmp_func, NULL);
>
> - return 0;
> end:
> - btf_free_dtor_kfunc_tab(btf);
> + if (ret)
> + btf_free_dtor_kfunc_tab(btf);
> btf_put(btf);
> return ret;
> }
> --
> 2.39.0
>
