On Wed, Mar 11, 2015 at 02:54:04PM +0100, [email protected] wrote: > > The patch below does not apply to the 3.10-stable tree. > If someone wants it applied there, or to any other stable or longterm > tree, then please email the backport, including the original git commit > id to <[email protected]>. > > thanks, > > greg k-h > > ------------------ original commit in Linus's tree ------------------ > > From a8bda28d87c38c6aa93de28ba5d30cc18e865a11 Mon Sep 17 00:00:00 2001 > From: Naoya Horiguchi <[email protected]> > Date: Wed, 11 Feb 2015 15:25:28 -0800 > Subject: [PATCH] mm/hugetlb: add migration/hwpoisoned entry check in > hugetlb_change_protection
The conflict is trivial enough to resolve, so please apply the below one. Thanks, Naoya Horiguchi --- >From 5babc2f225937be13d7c040d6d850128bd4f7ebf Mon Sep 17 00:00:00 2001 From: Naoya Horiguchi <[email protected]> Date: Mon, 16 Mar 2015 16:04:05 +0900 Subject: [PATCH] mm/hugetlb: add migration/hwpoisoned 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. HWPoison entries also can cause the same problem. This patch adds is_hugetlb_entry_(migration|hwpoisoned) check in this function to do proper actions. [[email protected]: resolve conflict to apply to v3.10.71] Fixes: 290408d4a2 ("hugetlb: hugepage migration core") Signed-off-by: Naoya Horiguchi <[email protected]> Cc: Hugh Dickins <[email protected]> Cc: James Hogan <[email protected]> Cc: David Rientjes <[email protected]> Cc: Mel Gorman <[email protected]> Cc: Johannes Weiner <[email protected]> Cc: Michal Hocko <[email protected]> Cc: Rik van Riel <[email protected]> Cc: Andrea Arcangeli <[email protected]> Cc: Luiz Capitulino <[email protected]> Cc: Nishanth Aravamudan <[email protected]> Cc: Lee Schermerhorn <[email protected]> Cc: Steve Capper <[email protected]> Cc: <[email protected]> [2.6.36+] Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]> --- mm/hugetlb.c | 21 ++++++++++++++++++++- 1 file changed, 20 insertions(+), 1 deletion(-) diff --git a/mm/hugetlb.c b/mm/hugetlb.c index 7de4f67c81fe..e25e32f5e0e1 100644 --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -3116,7 +3116,26 @@ unsigned long hugetlb_change_protection(struct vm_area_struct *vma, pages++; continue; } - if (!huge_pte_none(huge_ptep_get(ptep))) { + pte = huge_ptep_get(ptep); + if (unlikely(is_hugetlb_entry_hwpoisoned(pte))) { + spin_unlock(ptl); + continue; + } + if (unlikely(is_hugetlb_entry_migration(pte))) { + swp_entry_t entry = pte_to_swp_entry(pte); + + if (is_write_migration_entry(entry)) { + pte_t newpte; + + make_migration_entry_read(&entry); + newpte = swp_entry_to_pte(entry); + set_huge_pte_at(mm, address, ptep, newpte); + pages++; + } + 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); -- 1.9.3 -- 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
