Commit 3fab84f0 authored by Martin KaFai Lau's avatar Martin KaFai Lau Committed by Alexei Starovoitov
Browse files

bpf: Simplify reg0 marking for the list kfuncs that return a bpf_list_node pointer 



The next patch will add bpf_list_{front,back} kfuncs to peek the head
and tail of a list. Both of them will return a 'struct bpf_list_node *'.

Follow the earlier change for rbtree, this patch checks the
return btf type is a 'struct bpf_list_node' pointer instead
of checking each kfuncs individually to decide if
mark_reg_graph_node should be called. This will make
the bpf_list_{front,back} kfunc addition easier in
the later patch.

Acked-by: default avatarKumar Kartikeya Dwivedi <memxor@gmail.com>
Signed-off-by: default avatarMartin KaFai Lau <martin.lau@kernel.org>
Link: https://lore.kernel.org/r/20250506015857.817950-7-martin.lau@linux.dev


Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
parent 47ada65c

kernel/bpf/verifier.c

+6 −2
Original line number Diff line number Diff line
@@ -11992,6 +11992,11 @@ static bool is_rbtree_node_type(const struct btf_type *t) 
	return t == btf_type_by_id(btf_vmlinux, kf_arg_btf_ids[KF_ARG_RB_NODE_ID]);

}









static bool is_list_node_type(const struct btf_type *t)









{









	return t == btf_type_by_id(btf_vmlinux, kf_arg_btf_ids[KF_ARG_LIST_NODE_ID]);









}

















static bool is_kfunc_arg_callback(struct bpf_verifier_env *env, const struct btf *btf,









				  const struct btf_param *arg)









{








@@ -13764,8 +13769,7 @@ static int check_kfunc_call(struct bpf_verifier_env *env, struct bpf_insn *insn,







				insn_aux->kptr_struct_meta =









					btf_find_struct_meta(meta.arg_btf,









							     meta.arg_btf_id);









			} else if (meta.func_id == special_kfunc_list[KF_bpf_list_pop_front] ||









				   meta.func_id == special_kfunc_list[KF_bpf_list_pop_back]) {









			} else if (is_list_node_type(ptr_type)) {









				struct btf_field *field = meta.arg_list_head.field;

















				mark_reg_graph_node(regs, BPF_REG_0, &field->graph_root);