pagemap: fix large pages in pagemap

[linux-2.6-omap-h63xx.git] / fs / proc / task_mmu.c

diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c
index f0df3109343d7340e97a531af3d1978838184e41..ab8ccc9d14ff6df10abdd715076d870dafb32a85 100644 (file)
--- 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;