return true;
}
+static const struct btf_type *
+resolve_func_ptr(const struct btf *btf, __u32 id, __u32 *res_id)
+{
+ const struct btf_type *t;
+
+ t = skip_mods_and_typedefs(btf, id, NULL);
+ if (!btf_is_ptr(t))
+ return NULL;
+
+ t = skip_mods_and_typedefs(btf, t->type, res_id);
+
+ return btf_is_func_proto(t) ? t : NULL;
+}
+
static void get_obj_name(char *name, const char *file)
{
char file_copy[PATH_MAX];
}
}
+static int walk_st_ops_shadow_vars(struct btf *btf, const char *ident,
+ const struct btf_type *map_type, __u32 map_type_id)
+{
+ LIBBPF_OPTS(btf_dump_emit_type_decl_opts, opts, .indent_level = 3);
+ const struct btf_type *member_type;
+ __u32 offset, next_offset = 0;
+ const struct btf_member *m;
+ struct btf_dump *d = NULL;
+ const char *member_name;
+ __u32 member_type_id;
+ int i, err = 0, n;
+ int size;
+
+ d = btf_dump__new(btf, codegen_btf_dump_printf, NULL, NULL);
+ if (!d)
+ return -errno;
+
+ n = btf_vlen(map_type);
+ for (i = 0, m = btf_members(map_type); i < n; i++, m++) {
+ member_type = skip_mods_and_typedefs(btf, m->type, &member_type_id);
+ member_name = btf__name_by_offset(btf, m->name_off);
+
+ offset = m->offset / 8;
+ if (next_offset < offset)
+ printf("\t\t\tchar __padding_%d[%d];\n", i, offset - next_offset);
+
+ switch (btf_kind(member_type)) {
+ case BTF_KIND_INT:
+ case BTF_KIND_FLOAT:
+ case BTF_KIND_ENUM:
+ case BTF_KIND_ENUM64:
+ /* scalar type */
+ printf("\t\t\t");
+ opts.field_name = member_name;
+ err = btf_dump__emit_type_decl(d, member_type_id, &opts);
+ if (err) {
+ p_err("Failed to emit type declaration for %s: %d", member_name, err);
+ goto out;
+ }
+ printf(";\n");
+
+ size = btf__resolve_size(btf, member_type_id);
+ if (size < 0) {
+ p_err("Failed to resolve size of %s: %d\n", member_name, size);
+ err = size;
+ goto out;
+ }
+
+ next_offset = offset + size;
+ break;
+
+ case BTF_KIND_PTR:
+ if (resolve_func_ptr(btf, m->type, NULL)) {
+ /* Function pointer */
+ printf("\t\t\tstruct bpf_program *%s;\n", member_name);
+
+ next_offset = offset + sizeof(void *);
+ break;
+ }
+ /* All pointer types are unsupported except for
+ * function pointers.
+ */
+ fallthrough;
+
+ default:
+ /* Unsupported types
+ *
+ * Types other than scalar types and function
+ * pointers are currently not supported in order to
+ * prevent conflicts in the generated code caused
+ * by multiple definitions. For instance, if the
+ * struct type FOO is used in a struct_ops map,
+ * bpftool has to generate definitions for FOO,
+ * which may result in conflicts if FOO is defined
+ * in different skeleton files.
+ */
+ size = btf__resolve_size(btf, member_type_id);
+ if (size < 0) {
+ p_err("Failed to resolve size of %s: %d\n", member_name, size);
+ err = size;
+ goto out;
+ }
+ printf("\t\t\tchar __unsupported_%d[%d];\n", i, size);
+
+ next_offset = offset + size;
+ break;
+ }
+ }
+
+ /* Cannot fail since it must be a struct type */
+ size = btf__resolve_size(btf, map_type_id);
+ if (next_offset < (__u32)size)
+ printf("\t\t\tchar __padding_end[%d];\n", size - next_offset);
+
+out:
+ btf_dump__free(d);
+
+ return err;
+}
+
+/* Generate the pointer of the shadow type for a struct_ops map.
+ *
+ * This function adds a pointer of the shadow type for a struct_ops map.
+ * The members of a struct_ops map can be exported through a pointer to a
+ * shadow type. The user can access these members through the pointer.
+ *
+ * A shadow type includes not all members, only members of some types.
+ * They are scalar types and function pointers. The function pointers are
+ * translated to the pointer of the struct bpf_program. The scalar types
+ * are translated to the original type without any modifiers.
+ *
+ * Unsupported types will be translated to a char array to occupy the same
+ * space as the original field, being renamed as __unsupported_*. The user
+ * should treat these fields as opaque data.
+ */
+static int gen_st_ops_shadow_type(const char *obj_name, struct btf *btf, const char *ident,
+ const struct bpf_map *map)
+{
+ const struct btf_type *map_type;
+ const char *type_name;
+ __u32 map_type_id;
+ int err;
+
+ map_type_id = bpf_map__btf_value_type_id(map);
+ if (map_type_id == 0)
+ return -EINVAL;
+ map_type = btf__type_by_id(btf, map_type_id);
+ if (!map_type)
+ return -EINVAL;
+
+ type_name = btf__name_by_offset(btf, map_type->name_off);
+
+ printf("\t\tstruct %s__%s__%s {\n", obj_name, ident, type_name);
+
+ err = walk_st_ops_shadow_vars(btf, ident, map_type, map_type_id);
+ if (err)
+ return err;
+
+ printf("\t\t} *%s;\n", ident);
+
+ return 0;
+}
+
+static int gen_st_ops_shadow(const char *obj_name, struct btf *btf, struct bpf_object *obj)
+{
+ int err, st_ops_cnt = 0;
+ struct bpf_map *map;
+ char ident[256];
+
+ if (!btf)
+ return 0;
+
+ /* Generate the pointers to shadow types of
+ * struct_ops maps.
+ */
+ bpf_object__for_each_map(map, obj) {
+ if (bpf_map__type(map) != BPF_MAP_TYPE_STRUCT_OPS)
+ continue;
+ if (!get_map_ident(map, ident, sizeof(ident)))
+ continue;
+
+ if (st_ops_cnt == 0) /* first struct_ops map */
+ printf("\tstruct {\n");
+ st_ops_cnt++;
+
+ err = gen_st_ops_shadow_type(obj_name, btf, ident, map);
+ if (err)
+ return err;
+ }
+
+ if (st_ops_cnt)
+ printf("\t} struct_ops;\n");
+
+ return 0;
+}
+
+/* Generate the code to initialize the pointers of shadow types. */
+static void gen_st_ops_shadow_init(struct btf *btf, struct bpf_object *obj)
+{
+ struct bpf_map *map;
+ char ident[256];
+
+ if (!btf)
+ return;
+
+ /* Initialize the pointers to_ops shadow types of
+ * struct_ops maps.
+ */
+ bpf_object__for_each_map(map, obj) {
+ if (bpf_map__type(map) != BPF_MAP_TYPE_STRUCT_OPS)
+ continue;
+ if (!get_map_ident(map, ident, sizeof(ident)))
+ continue;
+ codegen("\
+ \n\
+ obj->struct_ops.%1$s = bpf_map__initial_value(obj->maps.%1$s, NULL);\n\
+ \n\
+ ", ident);
+ }
+}
+
static int do_skeleton(int argc, char **argv)
{
char header_guard[MAX_OBJ_NAME_LEN + sizeof("__SKEL_H__")];
printf("\t} maps;\n");
}
+ btf = bpf_object__btf(obj);
+ err = gen_st_ops_shadow(obj_name, btf, obj);
+ if (err)
+ goto out;
+
if (prog_cnt) {
printf("\tstruct {\n");
bpf_object__for_each_program(prog, obj) {
printf("\t} links;\n");
}
- btf = bpf_object__btf(obj);
if (btf) {
err = codegen_datasecs(obj, obj_name);
if (err)
if (err) \n\
goto err_out; \n\
\n\
+ ", obj_name);
+
+ gen_st_ops_shadow_init(btf, obj);
+
+ codegen("\
+ \n\
return obj; \n\
err_out: \n\
%1$s__destroy(obj); \n\
printf("\t} maps;\n");
}
+ err = gen_st_ops_shadow(obj_name, btf, obj);
+ if (err)
+ goto out;
+
if (prog_cnt) {
printf("\tstruct {\n");
bpf_object__for_each_program(prog, obj) {
if (err) \n\
goto err; \n\
\n\
+ ");
+
+ gen_st_ops_shadow_init(btf, obj);
+
+ codegen("\
+ \n\
return obj; \n\
err: \n\
%1$s__destroy(obj); \n\
projects / linux.git / commitdiff