On Wed, Jun 07, 2023 at 02:40:02PM +0800, Yin Fengwei wrote: > > + page += offset / PAGE_SIZE; > > + offset %= PAGE_SIZE; > > + if (PageHighMem(page)) > > + n = min_t(size_t, bytes, PAGE_SIZE); > Should be PAGE_SIZE - offset instead of PAGE_SIZE? Yes, it should. Thanks.