What's the status of these two patches? On Mon, 2012-12-17 at 19:00 +0100, Andrea Arcangeli wrote: > Hi, > > I got a report for a minor regression introduced by commit > 027ef6c87853b0a9df53175063028edb4950d476. > > So the problem is, pageattr creates kernel pagetables (pte and pmds) > that breaks pte_present/pmd_present and the patch above exposed this > invariant breakage for pmd_present. > > The same problem already existed for the pte and pte_present and it > was fixed by commit 660a293ea9be709b893d371fbc0328fcca33c33a (if it > wasn't for that commit, it wouldn't even be a regression). That fix > avoids the pagefault to use pte_present. I could follow through by > stopping using pmd_present/pmd_huge too. > > However I think it's more robust to fix pageattr and to clear the > PSE/GLOBAL bitflags too in addition to the present bitflag. So the > kernel page fault can keep using the regular > pte_present/pmd_present/pmd_huge. > > The confusion arises because _PAGE_GLOBAL and _PAGE_PROTNONE are > sharing the same bit, and in the pmd case we pretend _PAGE_PSE to be > set only in present pmds (to facilitate split_huge_page final tlb > flush). > > Andrea Arcangeli (2): > Revert "x86, mm: Make spurious_fault check explicitly check the > PRESENT bit" > pageattr: prevent PSE and GLOABL leftovers to confuse pmd/pte_present > and pmd_huge > > arch/x86/mm/fault.c | 8 +------ > arch/x86/mm/pageattr.c | 50 +++++++++++++++++++++++++++++++++++++++++++++-- > 2 files changed, 48 insertions(+), 10 deletions(-) > > -- > To unsubscribe, send a message with 'unsubscribe linux-mm' in > the body to majordomo@xxxxxxxxx. For more info on Linux MM, > see: http://www.linux-mm.org/ . > Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a> -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>