On Thu, Sep 02, 2021 at 06:37:13AM +0000, jiasheng wrote:
> We have found that in the complied files env_stack_push()
> appear more than 10 times, and under at least 90% circumstances
> that env_type_is_resolved() and env_stack_push() appear in pairs.
> For example, they appear together in the btf_modifier_resolve()
> of the file complie from 'kernel/bpf/btf.c'.
> But we have found that in the btf_resolve(), there is only
> env_stack_push() instead of the pair.
> Therefore, we consider that the env_type_is_resolved()
> might be forgotten.
It does not justify a change like this just because
one of its usage looks different and then concluded that
it _might_ be forgotten.
Does it have a bug or not? If there is, please
provide an explanation on how to reproduce it first.
>
> Signed-off-by: jiasheng <jiasheng@xxxxxxxxxxx>
> ---
> kernel/bpf/btf.c | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/kernel/bpf/btf.c b/kernel/bpf/btf.c
> index f982a9f0..454c249 100644
> --- a/kernel/bpf/btf.c
> +++ b/kernel/bpf/btf.c
> @@ -4002,7 +4002,8 @@ static int btf_resolve(struct btf_verifier_env *env,
> int err = 0;
>
> env->resolve_mode = RESOLVE_TBD;
> - env_stack_push(env, t, type_id);
> + if (env_type_is_resolved(env, type_id))
> + env_stack_push(env, t, type_id);
> while (!err && (v = env_stack_peak(env))) {
> env->log_type_id = v->type_id;
> err = btf_type_ops(v->t)->resolve(env, v);
> --
> 2.7.4
>
