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> > + pteval_t pte_access = pte_val(pte) & access_mask; > > int i; > > > > - if (pte_write(pte) != pte_write(__ptep_get(ptep))) > > - return 1; > > - > > for (i = 0; i < ncontig; i++) { > > - pte_t orig_pte = __ptep_get(ptep + i); > > - > > - if (pte_dirty(pte) != pte_dirty(orig_pte)) > > - return 1; > > - > > - if (pte_young(pte) != pte_young(orig_pte)) > > + if ((pte_val(__ptep_get(ptep + i)) & access_mask) != pte_access) > > return 1; > > } > > I think, based on all the above, the current version is actually not buggy. But > I'm only willing to go to 95% confidence :) If I understand it right James already found and fixed a case that violated the invariant right? Maybe it is wise to be robust since things lock up if it goes wrong. Jason