On Nov 7, 2022, at 5:19 PM, Mike Kravetz <mike.kravetz@xxxxxxxxxx> wrote: > zap_page_range was originally designed to unmap pages within an address > range that could span multiple vmas. However, today all callers of > zap_page_range pass a range entirely within a single vma. In addition, > the mmu notification call within zap_page range is not correct as it > should be vma specific. > > Instead of fixing zap_page_range, change all callers to use zap_vma_range > as it is designed for ranges within a single vma. I understand the argument about mmu notifiers being broken (which is of course fixable). But, are the callers really able to guarantee that the ranges are all in a single VMA? I am not familiar with the users, but how for instance tcp_zerocopy_receive() can guarantee that no one did some mprotect() of some sorts that caused the original VMA to be split?
