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authorAndrea Arcangeli <aarcange@redhat.com>2011-01-13 15:46:54 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2011-01-13 17:32:42 -0800
commitf66055ab6fb9731dbfce320c5202ef4441b5d77f (patch)
treede347e42d1e5cf481344a153d272e86a95b774f4 /mm/memory.c
parent05759d380a9d7f131a475186c07fce58ceaa8902 (diff)
downloadlinux-f66055ab6fb9731dbfce320c5202ef4441b5d77f.tar.bz2
thp: verify pmd_trans_huge isn't leaking
pte_trans_huge must not leak in certain vmas like the mmio special pfn or filebacked mappings. Signed-off-by: Andrea Arcangeli <aarcange@redhat.com> Acked-by: Rik van Riel <riel@redhat.com> Acked-by: Mel Gorman <mel@csn.ul.ie> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/memory.c')
-rw-r--r--mm/memory.c7
1 files changed, 6 insertions, 1 deletions
diff --git a/mm/memory.c b/mm/memory.c
index 840ce9d98f8b..c1a80e00458d 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -1451,6 +1451,7 @@ int __get_user_pages(struct task_struct *tsk, struct mm_struct *mm,
pmd = pmd_offset(pud, pg);
if (pmd_none(*pmd))
return i ? : -EFAULT;
+ VM_BUG_ON(pmd_trans_huge(*pmd));
pte = pte_offset_map(pmd, pg);
if (pte_none(*pte)) {
pte_unmap(pte);
@@ -1675,8 +1676,10 @@ pte_t *__get_locked_pte(struct mm_struct *mm, unsigned long addr,
pud_t * pud = pud_alloc(mm, pgd, addr);
if (pud) {
pmd_t * pmd = pmd_alloc(mm, pud, addr);
- if (pmd)
+ if (pmd) {
+ VM_BUG_ON(pmd_trans_huge(*pmd));
return pte_alloc_map_lock(mm, pmd, addr, ptl);
+ }
}
return NULL;
}
@@ -1895,6 +1898,7 @@ static inline int remap_pmd_range(struct mm_struct *mm, pud_t *pud,
pmd = pmd_alloc(mm, pud, addr);
if (!pmd)
return -ENOMEM;
+ VM_BUG_ON(pmd_trans_huge(*pmd));
do {
next = pmd_addr_end(addr, end);
if (remap_pte_range(mm, pmd, addr, next,
@@ -3471,6 +3475,7 @@ static int __follow_pte(struct mm_struct *mm, unsigned long address,
goto out;
pmd = pmd_offset(pud, address);
+ VM_BUG_ON(pmd_trans_huge(*pmd));
if (pmd_none(*pmd) || unlikely(pmd_bad(*pmd)))
goto out;