1 files changed, 21 insertions, 130 deletions

diff --git a/mm/memory.c b/mm/memory.c
index f82b359b2745..2a8430844b6d 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -966,7 +966,7 @@ no_page_table:
          * has touched so far, we don't want to allocate page tables.
          */
         if (flags & FOLL_ANON) {
-                page = ZERO_PAGE(address);
+                page = ZERO_PAGE(0);
                 if (flags & FOLL_GET)
                         get_page(page);
                 BUG_ON(flags & FOLL_WRITE);
@@ -1111,95 +1111,6 @@ int get_user_pages(struct task_struct *tsk, struct mm_struct *mm,
 }
 EXPORT_SYMBOL(get_user_pages);
 
-static int zeromap_pte_range(struct mm_struct *mm, pmd_t *pmd,
-                        unsigned long addr, unsigned long end, pgprot_t prot)
-{
-        pte_t *pte;
-        spinlock_t *ptl;
-        int err = 0;
-
-        pte = pte_alloc_map_lock(mm, pmd, addr, &ptl);
-        if (!pte)
-                return -EAGAIN;
-        arch_enter_lazy_mmu_mode();
-        do {
-                struct page *page = ZERO_PAGE(addr);
-                pte_t zero_pte = pte_wrprotect(mk_pte(page, prot));
-
-                if (unlikely(!pte_none(*pte))) {
-                        err = -EEXIST;
-                        pte++;
-                        break;
-                }
-                page_cache_get(page);
-                page_add_file_rmap(page);
-                inc_mm_counter(mm, file_rss);
-                set_pte_at(mm, addr, pte, zero_pte);
-        } while (pte++, addr += PAGE_SIZE, addr != end);
-        arch_leave_lazy_mmu_mode();
-        pte_unmap_unlock(pte - 1, ptl);
-        return err;
-}
-
-static inline int zeromap_pmd_range(struct mm_struct *mm, pud_t *pud,
-                        unsigned long addr, unsigned long end, pgprot_t prot)
-{
-        pmd_t *pmd;
-        unsigned long next;
-        int err;
-
-        pmd = pmd_alloc(mm, pud, addr);
-        if (!pmd)
-                return -EAGAIN;
-        do {
-                next = pmd_addr_end(addr, end);
-                err = zeromap_pte_range(mm, pmd, addr, next, prot);
-                if (err)
-                        break;
-        } while (pmd++, addr = next, addr != end);
-        return err;
-}
-
-static inline int zeromap_pud_range(struct mm_struct *mm, pgd_t *pgd,
-                        unsigned long addr, unsigned long end, pgprot_t prot)
-{
-        pud_t *pud;
-        unsigned long next;
-        int err;
-
-        pud = pud_alloc(mm, pgd, addr);
-        if (!pud)
-                return -EAGAIN;
-        do {
-                next = pud_addr_end(addr, end);
-                err = zeromap_pmd_range(mm, pud, addr, next, prot);
-                if (err)
-                        break;
-        } while (pud++, addr = next, addr != end);
-        return err;
-}
-
-int zeromap_page_range(struct vm_area_struct *vma,
-                        unsigned long addr, unsigned long size, pgprot_t prot)
-{
-        pgd_t *pgd;
-        unsigned long next;
-        unsigned long end = addr + size;
-        struct mm_struct *mm = vma->vm_mm;
-        int err;
-
-        BUG_ON(addr >= end);
-        pgd = pgd_offset(mm, addr);
-        flush_cache_range(vma, addr, end);
-        do {
-                next = pgd_addr_end(addr, end);
-                err = zeromap_pud_range(mm, pgd, addr, next, prot);
-                if (err)
-                        break;
-        } while (pgd++, addr = next, addr != end);
-        return err;
-}
-
 pte_t * fastcall get_locked_pte(struct mm_struct *mm, unsigned long addr, spinlock_t **ptl)
 {
         pgd_t * pgd = pgd_offset(mm, addr);
@@ -1717,16 +1628,11 @@ gotten:
 
         if (unlikely(anon_vma_prepare(vma)))
                 goto oom;
-        if (old_page == ZERO_PAGE(address)) {
-                new_page = alloc_zeroed_user_highpage_movable(vma, address);
-                if (!new_page)
-                        goto oom;
-        } else {
-                new_page = alloc_page_vma(GFP_HIGHUSER_MOVABLE, vma, address);
-                if (!new_page)
-                        goto oom;
-                cow_user_page(new_page, old_page, address, vma);
-        }
+        VM_BUG_ON(old_page == ZERO_PAGE(0));
+        new_page = alloc_page_vma(GFP_HIGHUSER_MOVABLE, vma, address);
+        if (!new_page)
+                goto oom;
+        cow_user_page(new_page, old_page, address, vma);
 
         /*
          * Re-check the pte - we dropped the lock
@@ -2252,39 +2158,24 @@ static int do_anonymous_page(struct mm_struct *mm, struct vm_area_struct *vma,
         spinlock_t *ptl;
         pte_t entry;
 
-        if (write_access) {
-                /* Allocate our own private page. */
-                pte_unmap(page_table);
-
-                if (unlikely(anon_vma_prepare(vma)))
-                        goto oom;
-                page = alloc_zeroed_user_highpage_movable(vma, address);
-                if (!page)
-                        goto oom;
-
-                entry = mk_pte(page, vma->vm_page_prot);
-                entry = maybe_mkwrite(pte_mkdirty(entry), vma);
+        /* Allocate our own private page. */
+        pte_unmap(page_table);
 
-                page_table = pte_offset_map_lock(mm, pmd, address, &ptl);
-                if (!pte_none(*page_table))
-                        goto release;
-                inc_mm_counter(mm, anon_rss);
-                lru_cache_add_active(page);
-                page_add_new_anon_rmap(page, vma, address);
-        } else {
-                /* Map the ZERO_PAGE - vm_page_prot is readonly */
-                page = ZERO_PAGE(address);
-                page_cache_get(page);
-                entry = mk_pte(page, vma->vm_page_prot);
+        if (unlikely(anon_vma_prepare(vma)))
+                goto oom;
+        page = alloc_zeroed_user_highpage_movable(vma, address);
+        if (!page)
+                goto oom;
 
-                ptl = pte_lockptr(mm, pmd);
-                spin_lock(ptl);
-                if (!pte_none(*page_table))
-                        goto release;
-                inc_mm_counter(mm, file_rss);
-                page_add_file_rmap(page);
-        }
+        entry = mk_pte(page, vma->vm_page_prot);
+        entry = maybe_mkwrite(pte_mkdirty(entry), vma);
 
+        page_table = pte_offset_map_lock(mm, pmd, address, &ptl);
+        if (!pte_none(*page_table))
+                goto release;
+        inc_mm_counter(mm, anon_rss);
+        lru_cache_add_active(page);
+        page_add_new_anon_rmap(page, vma, address);
         set_pte_at(mm, address, page_table, entry);
 
         /* No need to invalidate - it was non-present before */