On Tue, 2024-05-07 at 23:32 -0700, Kui-Feng Lee wrote:
> The verifier uses field information for certain special types, such as
> kptr, rbtree root, and list head. These types are treated
> differently. However, we did not previously support these types in
> arrays. This update examines arrays and duplicates field information the
> same number of times as the length of the array if the element type is one
> of the special types.
>
> Signed-off-by: Kui-Feng Lee <thinker.li@xxxxxxxxx>
> ---
Acked-by: Eduard Zingerman <eddyz87@xxxxxxxxx>
[...]
> @@ -3504,6 +3539,19 @@ static int btf_find_field_one(const struct btf *btf,
> {
> int ret, align, sz, field_type;
> struct btf_field_info tmp;
> + const struct btf_array *array;
> + u32 i, nelems = 1;
> +
> + /* Walk into array types to find the element type and the number of
> + * elements in the (flattened) array.
> + */
> + for (i = 0; i < MAX_RESOLVE_DEPTH && btf_type_is_array(var_type); i++) {
> + array = btf_array(var_type);
> + nelems *= array->nelems;
> + var_type = btf_type_by_id(btf, array->type);
> + }
Nit: still think that error should be reported when i == MAX_RESOLVE_DEPTH.
> + if (nelems == 0)
> + return 0;
>
> field_type = btf_get_field_type(__btf_name_by_offset(btf, var_type->name_off),
> field_mask, seen_mask, &align, &sz);
[...]
