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>
This commit is contained in:
Andrea Arcangeli 2011-01-13 15:46:54 -08:00 committed by Linus Torvalds
parent 05759d380a
commit f66055ab6f

View File

@ -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;