YangZongzhen

In mappages, if `size` > 1 * `PAGESIZE` or `va` not page-aligned(i.e. need to map more than one page), it will lead to a memory leak with a midway `kalloc`...

运行环境: iPad Air (3rd generation) - iOS15.0.1 - v2.5.2(221)

目前主要观察到总下载量的问题。 下午重启clash后，总下载量重新计数，不知道有没有办法解决？