arena_free_pages
static void arena_free_pages(struct bpf_arena *arena, long uaddr, long page_cnt, bool sleepable);
arena_free_pages(arena, uaddr32, mapped, sleepable);
arena_free_pages(arena, (long)ptr__ign, page_cnt, true);
arena_free_pages(arena, (long)ptr__ign, page_cnt, false);