The patch titled
Subject: mm/hugetlb: add migration entry check in hugetlb_change_protection
has been added to the -mm tree. Its filename is
mm-hugetlb-add-migration-entry-check-in-hugetlb_change_protection.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/mm-hugetlb-add-migration-entry-check-in-hugetlb_change_protection.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/mm-hugetlb-add-migration-entry-check-in-hugetlb_change_protection.patch
Before you just go and hit "reply", please:
a) Consider who else should be cc'ed
b) Prefer to cc a suitable mailing list as well
c) Ideally: find the original patch on the mailing list and do a
reply-to-all to that, adding suitable additional cc's
*** Remember to use Documentation/SubmitChecklist when testing your code ***
The -mm tree is included into linux-next and is updated
there every 3-4 working days
------------------------------------------------------
From: Naoya Horiguchi <[email protected]>
Subject: mm/hugetlb: add migration entry check in hugetlb_change_protection
There is a race condition between hugepage migration and
change_protection(), where hugetlb_change_protection() doesn't care about
migration entries and wrongly overwrites them. That causes unexpected
results like kernel crash.
This patch adds is_hugetlb_entry_(migration|hwpoisoned) check in this
function and skip all such entries.
Signed-off-by: Naoya Horiguchi <[email protected]>
Cc: Hugh Dickins <[email protected]>
Cc: David Rientjes <[email protected]>
Cc: Christoph Lameter <[email protected]>
Cc: Mel Gorman <[email protected]>
Cc: <[email protected]> [3.12+]
Signed-off-by: Andrew Morton <[email protected]>
---
mm/hugetlb.c | 8 +++++++-
1 file changed, 7 insertions(+), 1 deletion(-)
diff -puN
mm/hugetlb.c~mm-hugetlb-add-migration-entry-check-in-hugetlb_change_protection
mm/hugetlb.c
---
a/mm/hugetlb.c~mm-hugetlb-add-migration-entry-check-in-hugetlb_change_protection
+++ a/mm/hugetlb.c
@@ -3358,7 +3358,13 @@ unsigned long hugetlb_change_protection(
spin_unlock(ptl);
continue;
}
- if (!huge_pte_none(huge_ptep_get(ptep))) {
+ pte = huge_ptep_get(ptep);
+ if (unlikely(is_hugetlb_entry_migration(pte) ||
+ is_hugetlb_entry_hwpoisoned(pte))) {
+ spin_unlock(ptl);
+ continue;
+ }
+ if (!huge_pte_none(pte)) {
pte = huge_ptep_get_and_clear(mm, address, ptep);
pte = pte_mkhuge(huge_pte_modify(pte, newprot));
pte = arch_make_huge_pte(pte, vma, NULL, 0);
_
Patches currently in -mm which might be from [email protected] are
origin.patch
mm-memcontrol-rewrite-charge-api-fix-hugetlb-charging.patch
mm-memcontrol-use-page-lists-for-uncharge-batching-fix-hugetlb-page-lru.patch
mm-update-the-description-for-madvise_remove.patch
mm-hwpoison-injectc-remove-unnecessary-null-test-before-debugfs_remove_recursive.patch
hwpoison-fix-race-with-changing-page-during-offlining-v2.patch
mm-hugetlb-generalize-writes-to-nr_hugepages.patch
mm-hugetlb-generalize-writes-to-nr_hugepages-fix.patch
mm-hugetlb-remove-hugetlb_zero-and-hugetlb_infinity.patch
mm-fix-potential-infinite-loop-in-dissolve_free_huge_pages.patch
mm-fix-potential-infinite-loop-in-dissolve_free_huge_pages-fix.patch
mm-softdirty-respect-vm_softdirty-in-pte-holes.patch
mm-hugetlb-take-refcount-under-page-table-lock-in-follow_huge_pmd.patch
mm-hugetlb-use-get_page_unless_zero-in-hugetlb_fault.patch
mm-hugetlb-add-migration-entry-check-in-hugetlb_change_protection.patch
mm-introduce-do_shared_fault-and-drop-do_fault-fix-fix.patch
do_shared_fault-check-that-mmap_sem-is-held.patch
linux-next.patch
--
To unsubscribe from this list: send the line "unsubscribe stable" in
the body of a message to [email protected]
More majordomo info at http://vger.kernel.org/majordomo-info.html
