mm: more rmap checking

[sfrench/cifs-2.6.git] / mm / memory.c

diff --git a/mm/memory.c b/mm/memory.c
index e7066e71dfa3b36daeb4830e3032091e38f0bfc1..cb94488ab96dad4eb3840fa037a7b08673154674 100644 (file)
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -481,7 +481,7 @@ copy_one_pte(struct mm_struct *dst_mm, struct mm_struct *src_mm,
        page = vm_normal_page(vma, addr, pte);
        if (page) {
                get_page(page);
-               page_dup_rmap(page);
+               page_dup_rmap(page, vma, addr);
                rss[!!PageAnon(page)]++;
        }
 
@@ -1448,6 +1448,100 @@ int remap_pfn_range(struct vm_area_struct *vma, unsigned long addr,
 }
 EXPORT_SYMBOL(remap_pfn_range);
 
+static int apply_to_pte_range(struct mm_struct *mm, pmd_t *pmd,
+                                    unsigned long addr, unsigned long end,
+                                    pte_fn_t fn, void *data)
+{
+       pte_t *pte;
+       int err;
+       struct page *pmd_page;
+       spinlock_t *uninitialized_var(ptl);
+
+       pte = (mm == &init_mm) ?
+               pte_alloc_kernel(pmd, addr) :
+               pte_alloc_map_lock(mm, pmd, addr, &ptl);
+       if (!pte)
+               return -ENOMEM;
+
+       BUG_ON(pmd_huge(*pmd));
+
+       pmd_page = pmd_page(*pmd);
+
+       do {
+               err = fn(pte, pmd_page, addr, data);
+               if (err)
+                       break;
+       } while (pte++, addr += PAGE_SIZE, addr != end);
+
+       if (mm != &init_mm)
+               pte_unmap_unlock(pte-1, ptl);
+       return err;
+}
+
+static int apply_to_pmd_range(struct mm_struct *mm, pud_t *pud,
+                                    unsigned long addr, unsigned long end,
+                                    pte_fn_t fn, void *data)
+{
+       pmd_t *pmd;
+       unsigned long next;
+       int err;
+
+       pmd = pmd_alloc(mm, pud, addr);
+       if (!pmd)
+               return -ENOMEM;
+       do {
+               next = pmd_addr_end(addr, end);
+               err = apply_to_pte_range(mm, pmd, addr, next, fn, data);
+               if (err)
+                       break;
+       } while (pmd++, addr = next, addr != end);
+       return err;
+}
+
+static int apply_to_pud_range(struct mm_struct *mm, pgd_t *pgd,
+                                    unsigned long addr, unsigned long end,
+                                    pte_fn_t fn, void *data)
+{
+       pud_t *pud;
+       unsigned long next;
+       int err;
+
+       pud = pud_alloc(mm, pgd, addr);
+       if (!pud)
+               return -ENOMEM;
+       do {
+               next = pud_addr_end(addr, end);
+               err = apply_to_pmd_range(mm, pud, addr, next, fn, data);
+               if (err)
+                       break;
+       } while (pud++, addr = next, addr != end);
+       return err;
+}
+
+/*
+ * Scan a region of virtual memory, filling in page tables as necessary
+ * and calling a provided function on each leaf page table.
+ */
+int apply_to_page_range(struct mm_struct *mm, unsigned long addr,
+                       unsigned long size, pte_fn_t fn, void *data)
+{
+       pgd_t *pgd;
+       unsigned long next;
+       unsigned long end = addr + size;
+       int err;
+
+       BUG_ON(addr >= end);
+       pgd = pgd_offset(mm, addr);
+       do {
+               next = pgd_addr_end(addr, end);
+               err = apply_to_pud_range(mm, pgd, addr, next, fn, data);
+               if (err)
+                       break;
+       } while (pgd++, addr = next, addr != end);
+       return err;
+}
+EXPORT_SYMBOL_GPL(apply_to_page_range);
+
 /*
  * handle_pte_fault chooses page fault handler according to an entry
  * which was read non-atomically.  Before making any commitment, on
@@ -2539,12 +2633,6 @@ int __pud_alloc(struct mm_struct *mm, pgd_t *pgd, unsigned long address)
        spin_unlock(&mm->page_table_lock);
        return 0;
 }
-#else
-/* Workaround for gcc 2.96 */
-int __pud_alloc(struct mm_struct *mm, pgd_t *pgd, unsigned long address)
-{
-       return 0;
-}
 #endif /* __PAGETABLE_PUD_FOLDED */
 
 #ifndef __PAGETABLE_PMD_FOLDED
@@ -2573,12 +2661,6 @@ int __pmd_alloc(struct mm_struct *mm, pud_t *pud, unsigned long address)
        spin_unlock(&mm->page_table_lock);
        return 0;
 }
-#else
-/* Workaround for gcc 2.96 */
-int __pmd_alloc(struct mm_struct *mm, pud_t *pud, unsigned long address)
-{
-       return 0;
-}
 #endif /* __PAGETABLE_PMD_FOLDED */
 
 int make_pages_present(unsigned long addr, unsigned long end)