On Oct 3, 2022, at 4:17 PM, Nadav Amit <nadav.amit@xxxxxxxxx> wrote: > On Oct 3, 2022, at 3:28 PM, Edgecombe, Rick P <rick.p.edgecombe@xxxxxxxxx> wrote: > >> On Mon, 2022-10-03 at 11:11 -0700, Nadav Amit wrote: >>> Did you have a look at ptep_set_access_flags() and friends and >>> checked they >>> do not need to be changed too? >> >> ptep_set_access_flags() doesn't actually set any additional dirty bits >> on x86, so I think it's ok. > > Are you sure about that? (lost my confidence today so I am hesitant). > > Looking on insert_pfn(), I see: > > entry = maybe_mkwrite(pte_mkdirty(entry), vma); > if (ptep_set_access_flags(vma, addr, pte, entry, 1)) ... > > This appears to set the dirty bit while potentially leaving the write-bit > clear. This is the scenario you want to avoid, no? No. I am not paying attention. Ignore.
