1 files changed, 45 insertions, 0 deletions

diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c
index 2a1bef9203c6..47c03f4336b8 100644
--- a/fs/proc/task_mmu.c
+++ b/fs/proc/task_mmu.c
@@ -650,6 +650,50 @@ static int pagemap_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end,
         return err;
 }
 
+static u64 huge_pte_to_pagemap_entry(pte_t pte, int offset)
+{
+        u64 pme = 0;
+        if (pte_present(pte))
+                pme = PM_PFRAME(pte_pfn(pte) + offset)
+                        | PM_PSHIFT(PAGE_SHIFT) | PM_PRESENT;
+        return pme;
+}
+
+static int pagemap_hugetlb_range(pte_t *pte, unsigned long addr,
+                                 unsigned long end, struct mm_walk *walk)
+{
+        struct vm_area_struct *vma;
+        struct pagemapread *pm = walk->private;
+        struct hstate *hs = NULL;
+        int err = 0;
+
+        vma = find_vma(walk->mm, addr);
+        if (vma)
+                hs = hstate_vma(vma);
+        for (; addr != end; addr += PAGE_SIZE) {
+                u64 pfn = PM_NOT_PRESENT;
+
+                if (vma && (addr >= vma->vm_end)) {
+                        vma = find_vma(walk->mm, addr);
+                        if (vma)
+                                hs = hstate_vma(vma);
+                }
+
+                if (vma && (vma->vm_start <= addr) && is_vm_hugetlb_page(vma)) {
+                        /* calculate pfn of the "raw" page in the hugepage. */
+                        int offset = (addr & ~huge_page_mask(hs)) >> PAGE_SHIFT;
+                        pfn = huge_pte_to_pagemap_entry(*pte, offset);
+                }
+                err = add_to_pagemap(addr, pfn, pm);
+                if (err)
+                        return err;
+        }
+
+        cond_resched();
+
+        return err;
+}
+
 /*
  * /proc/pid/pagemap - an array mapping virtual pages to pfns
  *
@@ -742,6 +786,7 @@ static ssize_t pagemap_read(struct file *file, char __user *buf,
 
         pagemap_walk.pmd_entry = pagemap_pte_range;
         pagemap_walk.pte_hole = pagemap_pte_hole;
+        pagemap_walk.hugetlb_entry = pagemap_hugetlb_range;
         pagemap_walk.mm = mm;
         pagemap_walk.private = &pm;