From: Philo Lu Date: Fri, 5 Apr 2024 02:55:35 +0000 (+0800) Subject: bpf: allow invoking bpf_for_each_map_elem with different maps X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=9d482da9e17a4ddd5563428f74302a36b2610306;p=linux.git bpf: allow invoking bpf_for_each_map_elem with different maps Taking different maps within a single bpf_for_each_map_elem call is not allowed before, because from the second map, bpf_insn_aux_data->map_ptr_state will be marked as *poison*. In fact both map_ptr and state are needed to support this use case: map_ptr is used by set_map_elem_callback_state() while poison state is needed to determine whether to use direct call. Signed-off-by: Philo Lu Acked-by: Yonghong Song Link: https://lore.kernel.org/r/20240405025536.18113-3-lulie@linux.alibaba.com Signed-off-by: Alexei Starovoitov --- diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index 62fedb1f33127..590db4e4c071c 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -9651,11 +9651,7 @@ static int set_map_elem_callback_state(struct bpf_verifier_env *env, struct bpf_map *map; int err; - if (bpf_map_ptr_poisoned(insn_aux)) { - verbose(env, "tail_call abusing map_ptr\n"); - return -EINVAL; - } - + /* valid map_ptr and poison value does not matter */ map = insn_aux->map_ptr_state.map_ptr; if (!map->ops->map_set_for_each_callback_args || !map->ops->map_for_each_callback) {