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| author | Andrea Arcangeli <aarcange@redhat.com> | 2011-01-13 15:46:54 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2011-01-13 17:32:42 -0800 |
| commit | f66055ab6fb9731dbfce320c5202ef4441b5d77f (patch) | |
| tree | de347e42d1e5cf481344a153d272e86a95b774f4 | |
| parent | 05759d380a9d7f131a475186c07fce58ceaa8902 (diff) | |
| download | lwn-f66055ab6fb9731dbfce320c5202ef4441b5d77f.tar.gz lwn-f66055ab6fb9731dbfce320c5202ef4441b5d77f.zip | |
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>
| -rw-r--r-- | mm/memory.c | 7 |
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; |