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 */