Commit 887c31a3 authored by Jiri Olsa's avatar Jiri Olsa Committed by Alexei Starovoitov
Browse files

bpf: Add type_id pointer as argument to __btf_resolve_size 



Adding type_id pointer as argument to __btf_resolve_size
to return also BTF ID of the resolved type. It will be
used in following changes.

Signed-off-by: default avatarJiri Olsa <jolsa@kernel.org>
Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
Acked-by: default avatarAndrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/20200825192124.710397-6-jolsa@kernel.org
parent 69ff3047

kernel/bpf/btf.c

+9 −4
Original line number Diff line number Diff line
@@ -1082,6 +1082,7 @@ static const struct resolve_vertex *env_stack_peak(struct btf_verifier_env *env) 
 * *elem_id: id of u32

 * *total_nelems: (x * y).  Hence, individual elem size is

 *                (*type_size / *total_nelems)

 * *type_id: id of type if it's changed within the function, 0 if not

 *

 * type: is not an array (e.g. const struct X)

 * return type: type "struct X"
@@ -1089,15 +1090,16 @@ static const struct resolve_vertex *env_stack_peak(struct btf_verifier_env *env) 
 * *elem_type: same as return type ("struct X")

 * *elem_id: 0

 * *total_nelems: 1

 * *type_id: id of type if it's changed within the function, 0 if not

 */

static const struct btf_type *

__btf_resolve_size(const struct btf *btf, const struct btf_type *type,

		   u32 *type_size, const struct btf_type **elem_type,

		   u32 *elem_id, u32 *total_nelems)

		   u32 *elem_id, u32 *total_nelems, u32 *type_id)

{

	const struct btf_type *array_type = NULL;

	const struct btf_array *array = NULL;

	u32 i, size, nelems = 1;

	u32 i, size, nelems = 1, id = 0;



	for (i = 0; i < MAX_RESOLVE_DEPTH; i++) {

		switch (BTF_INFO_KIND(type->info)) {
@@ -1118,6 +1120,7 @@ __btf_resolve_size(const struct btf *btf, const struct btf_type *type, 
		case BTF_KIND_VOLATILE:

		case BTF_KIND_CONST:

		case BTF_KIND_RESTRICT:

			id = type->type;

			type = btf_type_by_id(btf, type->type);

			break;
@@ -1150,6 +1153,8 @@ __btf_resolve_size(const struct btf *btf, const struct btf_type *type, 
		*elem_type = type;

	if (elem_id)

		*elem_id = array ? array->type : 0;

	if (type_id && id)

		*type_id = id;



	return array_type ? : type;

}
@@ -1158,7 +1163,7 @@ const struct btf_type * 
btf_resolve_size(const struct btf *btf, const struct btf_type *type,

		 u32 *type_size)

{

	return __btf_resolve_size(btf, type, type_size, NULL, NULL);

	return __btf_resolve_size(btf, type, type_size, NULL, NULL, NULL, NULL);

}



/* The input param "type_id" must point to a needs_resolve type */
@@ -3988,7 +3993,7 @@ int btf_struct_access(struct bpf_verifier_log *log, 
		mname = __btf_name_by_offset(btf_vmlinux, member->name_off);



		mtype = __btf_resolve_size(btf_vmlinux, mtype, &msize,

					   &elem_type, NULL, &total_nelems);

					   &elem_type, NULL, &total_nelems, NULL);

		if (IS_ERR(mtype)) {

			bpf_log(log, "field %s doesn't have size\n", mname);

			return -EFAULT;