Subject: [merged] mm-new_vma_page-cannot-see-null-vma-for-hugetlb-pages.patch removed from -mm tree
To: mhocko@xxxxxxx,bob.liu@xxxxxxxxxx,liwanp@xxxxxxxxxxxxxxxxxx,n-horiguchi@xxxxxxxxxxxxx,sasha.levin@xxxxxxxxxx,mm-commits@xxxxxxxxxxxxxxx
From: akpm@xxxxxxxxxxxxxxxxxxxx
Date: Fri, 24 Jan 2014 10:59:05 -0800
The patch titled
Subject: mm: new_vma_page() cannot see NULL vma for hugetlb pages
has been removed from the -mm tree. Its filename was
mm-new_vma_page-cannot-see-null-vma-for-hugetlb-pages.patch
This patch was dropped because it was merged into mainline or a subsystem tree
------------------------------------------------------
From: Michal Hocko <mhocko@xxxxxxx>
Subject: mm: new_vma_page() cannot see NULL vma for hugetlb pages
11c731e81bb0 ("mm/mempolicy: fix !vma in new_vma_page()") has removed
BUG_ON(!vma) from new_vma_page which is partially correct because
page_address_in_vma will return EFAULT for non-linear mappings and at
least shared shmem might be mapped this way.
The patch also tried to prevent NULL ptr for hugetlb pages which is not
correct AFAICS because hugetlb pages cannot be mapped as VM_NONLINEAR and
other conditions in page_address_in_vma seem to be legit and catch real
bugs.
This patch restores BUG_ON for PageHuge to catch potential issues when the
to-be-migrated page is not setup properly.
Signed-off-by: Michal Hocko <mhocko@xxxxxxx>
Reviewed-by: Bob Liu <bob.liu@xxxxxxxxxx>
Cc: Sasha Levin <sasha.levin@xxxxxxxxxx>
Cc: Wanpeng Li <liwanp@xxxxxxxxxxxxxxxxxx>
Cc: Naoya Horiguchi <n-horiguchi@xxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/mempolicy.c | 6 ++----
1 file changed, 2 insertions(+), 4 deletions(-)
diff -puN mm/mempolicy.c~mm-new_vma_page-cannot-see-null-vma-for-hugetlb-pages mm/mempolicy.c
--- a/mm/mempolicy.c~mm-new_vma_page-cannot-see-null-vma-for-hugetlb-pages
+++ a/mm/mempolicy.c
@@ -1199,10 +1199,8 @@ static struct page *new_vma_page(struct
}
if (PageHuge(page)) {
- if (vma)
- return alloc_huge_page_noerr(vma, address, 1);
- else
- return NULL;
+ BUG_ON(!vma);
+ return alloc_huge_page_noerr(vma, address, 1);
}
/*
* if !vma, alloc_page_vma() will use task or system default policy
_
Patches currently in -mm which might be from mhocko@xxxxxxx are
origin.patch
mm-page_alloc-allow-__gfp_nofail-to-allocate-below-watermarks-after-reclaim.patch
memcg-do-not-hang-on-oom-when-killed-by-userspace-oom-access-to-memory-reserves.patch
mm-vmscan-respect-numa-policy-mask-when-shrinking-slab-on-direct-reclaim.patch
mm-vmscan-move-call-to-shrink_slab-to-shrink_zones.patch
mm-vmscan-remove-shrink_control-arg-from-do_try_to_free_pages.patch
--
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