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-rw-r--r--fs/proc/task_mmu.c39
1 files changed, 30 insertions, 9 deletions
diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c
index f0df3109343..ab8ccc9d14f 100644
--- a/fs/proc/task_mmu.c
+++ b/fs/proc/task_mmu.c
@@ -553,24 +553,45 @@ static u64 swap_pte_to_pagemap_entry(pte_t pte)
return swp_type(e) | (swp_offset(e) << MAX_SWAPFILES_SHIFT);
}
+static unsigned long pte_to_pagemap_entry(pte_t pte)
+{
+ unsigned long pme = 0;
+ if (is_swap_pte(pte))
+ pme = PM_PFRAME(swap_pte_to_pagemap_entry(pte))
+ | PM_PSHIFT(PAGE_SHIFT) | PM_SWAP;
+ else if (pte_present(pte))
+ pme = PM_PFRAME(pte_pfn(pte))
+ | PM_PSHIFT(PAGE_SHIFT) | PM_PRESENT;
+ return pme;
+}
+
static int pagemap_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end,
struct mm_walk *walk)
{
+ struct vm_area_struct *vma;
struct pagemapread *pm = walk->private;
pte_t *pte;
int err = 0;
+ /* find the first VMA at or above 'addr' */
+ vma = find_vma(walk->mm, addr);
for (; addr != end; addr += PAGE_SIZE) {
u64 pfn = PM_NOT_PRESENT;
- pte = pte_offset_map(pmd, addr);
- if (is_swap_pte(*pte))
- pfn = PM_PFRAME(swap_pte_to_pagemap_entry(*pte))
- | PM_PSHIFT(PAGE_SHIFT) | PM_SWAP;
- else if (pte_present(*pte))
- pfn = PM_PFRAME(pte_pfn(*pte))
- | PM_PSHIFT(PAGE_SHIFT) | PM_PRESENT;
- /* unmap so we're not in atomic when we copy to userspace */
- pte_unmap(pte);
+
+ /* check to see if we've left 'vma' behind
+ * and need a new, higher one */
+ if (vma && (addr >= vma->vm_end))
+ vma = find_vma(walk->mm, addr);
+
+ /* check that 'vma' actually covers this address,
+ * and that it isn't a huge page vma */
+ if (vma && (vma->vm_start <= addr) &&
+ !is_vm_hugetlb_page(vma)) {
+ pte = pte_offset_map(pmd, addr);
+ pfn = pte_to_pagemap_entry(*pte);
+ /* unmap before userspace copy */
+ pte_unmap(pte);
+ }
err = add_to_pagemap(addr, pfn, pm);
if (err)
return err;