Commit 9d482da9 authored by Philo Lu's avatar Philo Lu Committed by Alexei Starovoitov
Browse files

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: default avatarPhilo Lu <lulie@linux.alibaba.com>
Acked-by: default avatarYonghong Song <yonghong.song@linux.dev>
Link: https://lore.kernel.org/r/20240405025536.18113-3-lulie@linux.alibaba.com


Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
parent 0a525621

kernel/bpf/verifier.c

+1 −5
Original line number Diff line number Diff line
@@ -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) {