1 files changed, 149 insertions, 127 deletions

diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index 1546655a2d7..f8ffd9412ec 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -5,6 +5,8 @@
  *  the COPYING file in the top-level directory.
  */
 
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
 #include <linux/mm.h>
 #include <linux/sched.h>
 #include <linux/highmem.h>
@@ -151,8 +153,7 @@ static int start_khugepaged(void)
 			khugepaged_thread = kthread_run(khugepaged, NULL,
 							"khugepaged");
 		if (unlikely(IS_ERR(khugepaged_thread))) {
-			printk(KERN_ERR
-			       "khugepaged: kthread_run(khugepaged) failed\n");
+			pr_err("khugepaged: kthread_run(khugepaged) failed\n");
 			err = PTR_ERR(khugepaged_thread);
 			khugepaged_thread = NULL;
 		}
@@ -584,19 +585,19 @@ static int __init hugepage_init_sysfs(struct kobject **hugepage_kobj)
 
 	*hugepage_kobj = kobject_create_and_add("transparent_hugepage", mm_kobj);
 	if (unlikely(!*hugepage_kobj)) {
-		printk(KERN_ERR "hugepage: failed to create transparent hugepage kobject\n");
+		pr_err("failed to create transparent hugepage kobject\n");
 		return -ENOMEM;
 	}
 
 	err = sysfs_create_group(*hugepage_kobj, &hugepage_attr_group);
 	if (err) {
-		printk(KERN_ERR "hugepage: failed to register transparent hugepage group\n");
+		pr_err("failed to register transparent hugepage group\n");
 		goto delete_obj;
 	}
 
 	err = sysfs_create_group(*hugepage_kobj, &khugepaged_attr_group);
 	if (err) {
-		printk(KERN_ERR "hugepage: failed to register transparent hugepage group\n");
+		pr_err("failed to register transparent hugepage group\n");
 		goto remove_hp_group;
 	}
 
@@ -689,8 +690,7 @@ static int __init setup_transparent_hugepage(char *str)
 	}
 out:
 	if (!ret)
-		printk(KERN_WARNING
-		       "transparent_hugepage= cannot parse, ignored\n");
+		pr_warn("transparent_hugepage= cannot parse, ignored\n");
 	return ret;
 }
 __setup("transparent_hugepage=", setup_transparent_hugepage);
@@ -715,13 +715,20 @@ static int __do_huge_pmd_anonymous_page(struct mm_struct *mm,
 					unsigned long haddr, pmd_t *pmd,
 					struct page *page)
 {
+	struct mem_cgroup *memcg;
 	pgtable_t pgtable;
 	spinlock_t *ptl;
 
 	VM_BUG_ON_PAGE(!PageCompound(page), page);
+
+	if (mem_cgroup_try_charge(page, mm, GFP_TRANSHUGE, &memcg))
+		return VM_FAULT_OOM;
+
 	pgtable = pte_alloc_one(mm, haddr);
-	if (unlikely(!pgtable))
+	if (unlikely(!pgtable)) {
+		mem_cgroup_cancel_charge(page, memcg);
 		return VM_FAULT_OOM;
+	}
 
 	clear_huge_page(page, haddr, HPAGE_PMD_NR);
 	/*
@@ -734,7 +741,7 @@ static int __do_huge_pmd_anonymous_page(struct mm_struct *mm,
 	ptl = pmd_lock(mm, pmd);
 	if (unlikely(!pmd_none(*pmd))) {
 		spin_unlock(ptl);
-		mem_cgroup_uncharge_page(page);
+		mem_cgroup_cancel_charge(page, memcg);
 		put_page(page);
 		pte_free(mm, pgtable);
 	} else {
@@ -742,6 +749,8 @@ static int __do_huge_pmd_anonymous_page(struct mm_struct *mm,
 		entry = mk_huge_pmd(page, vma->vm_page_prot);
 		entry = maybe_pmd_mkwrite(pmd_mkdirty(entry), vma);
 		page_add_new_anon_rmap(page, vma, haddr);
+		mem_cgroup_commit_charge(page, memcg, false);
+		lru_cache_add_active_or_unevictable(page, vma);
 		pgtable_trans_huge_deposit(mm, pmd, pgtable);
 		set_pmd_at(mm, haddr, pmd, entry);
 		add_mm_counter(mm, MM_ANONPAGES, HPAGE_PMD_NR);
@@ -827,13 +836,7 @@ int do_huge_pmd_anonymous_page(struct mm_struct *mm, struct vm_area_struct *vma,
 		count_vm_event(THP_FAULT_FALLBACK);
 		return VM_FAULT_FALLBACK;
 	}
-	if (unlikely(mem_cgroup_newpage_charge(page, mm, GFP_KERNEL))) {
-		put_page(page);
-		count_vm_event(THP_FAULT_FALLBACK);
-		return VM_FAULT_FALLBACK;
-	}
 	if (unlikely(__do_huge_pmd_anonymous_page(mm, vma, haddr, pmd, page))) {
-		mem_cgroup_uncharge_page(page);
 		put_page(page);
 		count_vm_event(THP_FAULT_FALLBACK);
 		return VM_FAULT_FALLBACK;
@@ -941,79 +944,35 @@ unlock:
 	spin_unlock(ptl);
 }
 
-static int do_huge_pmd_wp_zero_page_fallback(struct mm_struct *mm,
-		struct vm_area_struct *vma, unsigned long address,
-		pmd_t *pmd, pmd_t orig_pmd, unsigned long haddr)
+/*
+ * Save CONFIG_DEBUG_PAGEALLOC from faulting falsely on tail pages
+ * during copy_user_huge_page()'s copy_page_rep(): in the case when
+ * the source page gets split and a tail freed before copy completes.
+ * Called under pmd_lock of checked pmd, so safe from splitting itself.
+ */
+static void get_user_huge_page(struct page *page)
 {
-	spinlock_t *ptl;
-	pgtable_t pgtable;
-	pmd_t _pmd;
-	struct page *page;
-	int i, ret = 0;
-	unsigned long mmun_start;	/* For mmu_notifiers */
-	unsigned long mmun_end;		/* For mmu_notifiers */
-
-	page = alloc_page_vma(GFP_HIGHUSER_MOVABLE, vma, address);
-	if (!page) {
-		ret |= VM_FAULT_OOM;
-		goto out;
-	}
+	if (IS_ENABLED(CONFIG_DEBUG_PAGEALLOC)) {
+		struct page *endpage = page + HPAGE_PMD_NR;
 
-	if (mem_cgroup_newpage_charge(page, mm, GFP_KERNEL)) {
-		put_page(page);
-		ret |= VM_FAULT_OOM;
-		goto out;
+		atomic_add(HPAGE_PMD_NR, &page->_count);
+		while (++page < endpage)
+			get_huge_page_tail(page);
+	} else {
+		get_page(page);
 	}
+}
 
-	clear_user_highpage(page, address);
-	__SetPageUptodate(page);
-
-	mmun_start = haddr;
-	mmun_end   = haddr + HPAGE_PMD_SIZE;
-	mmu_notifier_invalidate_range_start(mm, mmun_start, mmun_end);
-
-	ptl = pmd_lock(mm, pmd);
-	if (unlikely(!pmd_same(*pmd, orig_pmd)))
-		goto out_free_page;
-
-	pmdp_clear_flush(vma, haddr, pmd);
-	/* leave pmd empty until pte is filled */
-
-	pgtable = pgtable_trans_huge_withdraw(mm, pmd);
-	pmd_populate(mm, &_pmd, pgtable);
+static void put_user_huge_page(struct page *page)
+{
+	if (IS_ENABLED(CONFIG_DEBUG_PAGEALLOC)) {
+		struct page *endpage = page + HPAGE_PMD_NR;
 
-	for (i = 0; i < HPAGE_PMD_NR; i++, haddr += PAGE_SIZE) {
-		pte_t *pte, entry;
-		if (haddr == (address & PAGE_MASK)) {
-			entry = mk_pte(page, vma->vm_page_prot);
-			entry = maybe_mkwrite(pte_mkdirty(entry), vma);
-			page_add_new_anon_rmap(page, vma, haddr);
-		} else {
-			entry = pfn_pte(my_zero_pfn(haddr), vma->vm_page_prot);
-			entry = pte_mkspecial(entry);
-		}
-		pte = pte_offset_map(&_pmd, haddr);
-		VM_BUG_ON(!pte_none(*pte));
-		set_pte_at(mm, haddr, pte, entry);
-		pte_unmap(pte);
+		while (page < endpage)
+			put_page(page++);
+	} else {
+		put_page(page);
 	}
-	smp_wmb(); /* make pte visible before pmd */
-	pmd_populate(mm, pmd, pgtable);
-	spin_unlock(ptl);
-	put_huge_zero_page();
-	inc_mm_counter(mm, MM_ANONPAGES);
-
-	mmu_notifier_invalidate_range_end(mm, mmun_start, mmun_end);
-
-	ret |= VM_FAULT_WRITE;
-out:
-	return ret;
-out_free_page:
-	spin_unlock(ptl);
-	mmu_notifier_invalidate_range_end(mm, mmun_start, mmun_end);
-	mem_cgroup_uncharge_page(page);
-	put_page(page);
-	goto out;
 }
 
 static int do_huge_pmd_wp_page_fallback(struct mm_struct *mm,
@@ -1023,6 +982,7 @@ static int do_huge_pmd_wp_page_fallback(struct mm_struct *mm,
 					struct page *page,
 					unsigned long haddr)
 {
+	struct mem_cgroup *memcg;
 	spinlock_t *ptl;
 	pgtable_t pgtable;
 	pmd_t _pmd;
@@ -1043,20 +1003,21 @@ static int do_huge_pmd_wp_page_fallback(struct mm_struct *mm,
 					       __GFP_OTHER_NODE,
 					       vma, address, page_to_nid(page));
 		if (unlikely(!pages[i] ||
-			     mem_cgroup_newpage_charge(pages[i], mm,
-						       GFP_KERNEL))) {
+			     mem_cgroup_try_charge(pages[i], mm, GFP_KERNEL,
+						   &memcg))) {
 			if (pages[i])
 				put_page(pages[i]);
-			mem_cgroup_uncharge_start();
 			while (--i >= 0) {
-				mem_cgroup_uncharge_page(pages[i]);
+				memcg = (void *)page_private(pages[i]);
+				set_page_private(pages[i], 0);
+				mem_cgroup_cancel_charge(pages[i], memcg);
 				put_page(pages[i]);
 			}
-			mem_cgroup_uncharge_end();
 			kfree(pages);
 			ret |= VM_FAULT_OOM;
 			goto out;
 		}
+		set_page_private(pages[i], (unsigned long)memcg);
 	}
 
 	for (i = 0; i < HPAGE_PMD_NR; i++) {
@@ -1085,7 +1046,11 @@ static int do_huge_pmd_wp_page_fallback(struct mm_struct *mm,
 		pte_t *pte, entry;
 		entry = mk_pte(pages[i], vma->vm_page_prot);
 		entry = maybe_mkwrite(pte_mkdirty(entry), vma);
+		memcg = (void *)page_private(pages[i]);
+		set_page_private(pages[i], 0);
 		page_add_new_anon_rmap(pages[i], vma, haddr);
+		mem_cgroup_commit_charge(pages[i], memcg, false);
+		lru_cache_add_active_or_unevictable(pages[i], vma);
 		pte = pte_offset_map(&_pmd, haddr);
 		VM_BUG_ON(!pte_none(*pte));
 		set_pte_at(mm, haddr, pte, entry);
@@ -1109,12 +1074,12 @@ out:
 out_free_pages:
 	spin_unlock(ptl);
 	mmu_notifier_invalidate_range_end(mm, mmun_start, mmun_end);
-	mem_cgroup_uncharge_start();
 	for (i = 0; i < HPAGE_PMD_NR; i++) {
-		mem_cgroup_uncharge_page(pages[i]);
+		memcg = (void *)page_private(pages[i]);
+		set_page_private(pages[i], 0);
+		mem_cgroup_cancel_charge(pages[i], memcg);
 		put_page(pages[i]);
 	}
-	mem_cgroup_uncharge_end();
 	kfree(pages);
 	goto out;
 }
@@ -1125,6 +1090,7 @@ int do_huge_pmd_wp_page(struct mm_struct *mm, struct vm_area_struct *vma,
 	spinlock_t *ptl;
 	int ret = 0;
 	struct page *page = NULL, *new_page;
+	struct mem_cgroup *memcg;
 	unsigned long haddr;
 	unsigned long mmun_start;	/* For mmu_notifiers */
 	unsigned long mmun_end;		/* For mmu_notifiers */
@@ -1149,7 +1115,7 @@ int do_huge_pmd_wp_page(struct mm_struct *mm, struct vm_area_struct *vma,
 		ret |= VM_FAULT_WRITE;
 		goto out_unlock;
 	}
-	get_page(page);
+	get_user_huge_page(page);
 	spin_unlock(ptl);
 alloc:
 	if (transparent_hugepage_enabled(vma) &&
@@ -1161,8 +1127,8 @@ alloc:
 
 	if (unlikely(!new_page)) {
 		if (!page) {
-			ret = do_huge_pmd_wp_zero_page_fallback(mm, vma,
-					address, pmd, orig_pmd, haddr);
+			split_huge_page_pmd(vma, address, pmd);
+			ret |= VM_FAULT_FALLBACK;
 		} else {
 			ret = do_huge_pmd_wp_page_fallback(mm, vma, address,
 					pmd, orig_pmd, page, haddr);
@@ -1170,17 +1136,18 @@ alloc:
 				split_huge_page(page);
 				ret |= VM_FAULT_FALLBACK;
 			}
-			put_page(page);
+			put_user_huge_page(page);
 		}
 		count_vm_event(THP_FAULT_FALLBACK);
 		goto out;
 	}
 
-	if (unlikely(mem_cgroup_newpage_charge(new_page, mm, GFP_KERNEL))) {
+	if (unlikely(mem_cgroup_try_charge(new_page, mm,
+					   GFP_TRANSHUGE, &memcg))) {
 		put_page(new_page);
 		if (page) {
 			split_huge_page(page);
-			put_page(page);
+			put_user_huge_page(page);
 		} else
 			split_huge_page_pmd(vma, address, pmd);
 		ret |= VM_FAULT_FALLBACK;
@@ -1202,10 +1169,10 @@ alloc:
 
 	spin_lock(ptl);
 	if (page)
-		put_page(page);
+		put_user_huge_page(page);
 	if (unlikely(!pmd_same(*pmd, orig_pmd))) {
 		spin_unlock(ptl);
-		mem_cgroup_uncharge_page(new_page);
+		mem_cgroup_cancel_charge(new_page, memcg);
 		put_page(new_page);
 		goto out_mn;
 	} else {
@@ -1214,6 +1181,8 @@ alloc:
 		entry = maybe_pmd_mkwrite(pmd_mkdirty(entry), vma);
 		pmdp_clear_flush(vma, haddr, pmd);
 		page_add_new_anon_rmap(new_page, vma, haddr);
+		mem_cgroup_commit_charge(new_page, memcg, false);
+		lru_cache_add_active_or_unevictable(new_page, vma);
 		set_pmd_at(mm, haddr, pmd, entry);
 		update_mmu_cache_pmd(vma, address, pmd);
 		if (!page) {
@@ -1611,16 +1580,23 @@ pmd_t *page_check_address_pmd(struct page *page,
 			      enum page_check_address_pmd_flag flag,
 			      spinlock_t **ptl)
 {
+	pgd_t *pgd;
+	pud_t *pud;
 	pmd_t *pmd;
 
 	if (address & ~HPAGE_PMD_MASK)
 		return NULL;
 
-	pmd = mm_find_pmd(mm, address);
-	if (!pmd)
+	pgd = pgd_offset(mm, address);
+	if (!pgd_present(*pgd))
+		return NULL;
+	pud = pud_offset(pgd, address);
+	if (!pud_present(*pud))
 		return NULL;
+	pmd = pmd_offset(pud, address);
+
 	*ptl = pmd_lock(mm, pmd);
-	if (pmd_none(*pmd))
+	if (!pmd_present(*pmd))
 		goto unlock;
 	if (pmd_page(*pmd) != page)
 		goto unlock;
@@ -1718,7 +1694,7 @@ static void __split_huge_page_refcount(struct page *page,
 			   &page_tail->_count);
 
 		/* after clearing PageTail the gup refcount can be released */
-		smp_mb();
+		smp_mb__after_atomic();
 
 		/*
 		 * retain hwpoison flag of the poisoned tail page:
@@ -1812,21 +1788,24 @@ static int __split_huge_page_map(struct page *page,
 	if (pmd) {
 		pgtable = pgtable_trans_huge_withdraw(mm, pmd);
 		pmd_populate(mm, &_pmd, pgtable);
+		if (pmd_write(*pmd))
+			BUG_ON(page_mapcount(page) != 1);
 
 		haddr = address;
 		for (i = 0; i < HPAGE_PMD_NR; i++, haddr += PAGE_SIZE) {
 			pte_t *pte, entry;
 			BUG_ON(PageCompound(page+i));
+			/*
+			 * Note that pmd_numa is not transferred deliberately
+			 * to avoid any possibility that pte_numa leaks to
+			 * a PROT_NONE VMA by accident.
+			 */
 			entry = mk_pte(page + i, vma->vm_page_prot);
 			entry = maybe_mkwrite(pte_mkdirty(entry), vma);
 			if (!pmd_write(*pmd))
 				entry = pte_wrprotect(entry);
-			else
-				BUG_ON(page_mapcount(page) != 1);
 			if (!pmd_young(*pmd))
 				entry = pte_mkold(entry);
-			if (pmd_numa(*pmd))
-				entry = pte_mknuma(entry);
 			pte = pte_offset_map(&_pmd, haddr);
 			BUG_ON(!pte_none(*pte));
 			set_pte_at(mm, haddr, pte, entry);
@@ -1898,10 +1877,11 @@ static void __split_huge_page(struct page *page,
 	 * the newly established pmd of the child later during the
 	 * walk, to be able to set it as pmd_trans_splitting too.
 	 */
-	if (mapcount != page_mapcount(page))
-		printk(KERN_ERR "mapcount %d page_mapcount %d\n",
-		       mapcount, page_mapcount(page));
-	BUG_ON(mapcount != page_mapcount(page));
+	if (mapcount != page_mapcount(page)) {
+		pr_err("mapcount %d page_mapcount %d\n",
+			mapcount, page_mapcount(page));
+		BUG();
+	}
 
 	__split_huge_page_refcount(page, list);
 
@@ -1912,10 +1892,11 @@ static void __split_huge_page(struct page *page,
 		BUG_ON(is_vma_temporary_stack(vma));
 		mapcount2 += __split_huge_page_map(page, vma, addr);
 	}
-	if (mapcount != mapcount2)
-		printk(KERN_ERR "mapcount %d mapcount2 %d page_mapcount %d\n",
-		       mapcount, mapcount2, page_mapcount(page));
-	BUG_ON(mapcount != mapcount2);
+	if (mapcount != mapcount2) {
+		pr_err("mapcount %d mapcount2 %d page_mapcount %d\n",
+			mapcount, mapcount2, page_mapcount(page));
+		BUG();
+	}
 }
 
 /*
@@ -1966,17 +1947,22 @@ out:
 int hugepage_madvise(struct vm_area_struct *vma,
 		     unsigned long *vm_flags, int advice)
 {
-	struct mm_struct *mm = vma->vm_mm;
-
 	switch (advice) {
 	case MADV_HUGEPAGE:
+#ifdef CONFIG_S390
+		/*
+		 * qemu blindly sets MADV_HUGEPAGE on all allocations, but s390
+		 * can't handle this properly after s390_enable_sie, so we simply
+		 * ignore the madvise to prevent qemu from causing a SIGSEGV.
+		 */
+		if (mm_has_pgste(vma->vm_mm))
+			return 0;
+#endif
 		/*
 		 * Be somewhat over-protective like KSM for now!
 		 */
 		if (*vm_flags & (VM_HUGEPAGE | VM_NO_THP))
 			return -EINVAL;
-		if (mm->def_flags & VM_NOHUGEPAGE)
-			return -EINVAL;
 		*vm_flags &= ~VM_NOHUGEPAGE;
 		*vm_flags |= VM_HUGEPAGE;
 		/*
@@ -2263,6 +2249,30 @@ static void khugepaged_alloc_sleep(void)
 
 static int khugepaged_node_load[MAX_NUMNODES];
 
+static bool khugepaged_scan_abort(int nid)
+{
+	int i;
+
+	/*
+	 * If zone_reclaim_mode is disabled, then no extra effort is made to
+	 * allocate memory locally.
+	 */
+	if (!zone_reclaim_mode)
+		return false;
+
+	/* If there is a count for this node already, it must be acceptable */
+	if (khugepaged_node_load[nid])
+		return false;
+
+	for (i = 0; i < MAX_NUMNODES; i++) {
+		if (!khugepaged_node_load[i])
+			continue;
+		if (node_distance(nid, i) > RECLAIM_DISTANCE)
+			return true;
+	}
+	return false;
+}
+
 #ifdef CONFIG_NUMA
 static int khugepaged_find_target_node(void)
 {
@@ -2419,6 +2429,7 @@ static void collapse_huge_page(struct mm_struct *mm,
 	spinlock_t *pmd_ptl, *pte_ptl;
 	int isolated;
 	unsigned long hstart, hend;
+	struct mem_cgroup *memcg;
 	unsigned long mmun_start;	/* For mmu_notifiers */
 	unsigned long mmun_end;		/* For mmu_notifiers */
 
@@ -2429,7 +2440,8 @@ static void collapse_huge_page(struct mm_struct *mm,
 	if (!new_page)
 		return;
 
-	if (unlikely(mem_cgroup_newpage_charge(new_page, mm, GFP_KERNEL)))
+	if (unlikely(mem_cgroup_try_charge(new_page, mm,
+					   GFP_TRANSHUGE, &memcg)))
 		return;
 
 	/*
@@ -2453,8 +2465,6 @@ static void collapse_huge_page(struct mm_struct *mm,
 	pmd = mm_find_pmd(mm, address);
 	if (!pmd)
 		goto out;
-	if (pmd_trans_huge(*pmd))
-		goto out;
 
 	anon_vma_lock_write(vma->anon_vma);
 
@@ -2518,6 +2528,8 @@ static void collapse_huge_page(struct mm_struct *mm,
 	spin_lock(pmd_ptl);
 	BUG_ON(!pmd_none(*pmd));
 	page_add_new_anon_rmap(new_page, vma, address);
+	mem_cgroup_commit_charge(new_page, memcg, false);
+	lru_cache_add_active_or_unevictable(new_page, vma);
 	pgtable_trans_huge_deposit(mm, pmd, pgtable);
 	set_pmd_at(mm, address, pmd, _pmd);
 	update_mmu_cache_pmd(vma, address, pmd);
@@ -2531,7 +2543,7 @@ out_up_write:
 	return;
 
 out:
-	mem_cgroup_uncharge_page(new_page);
+	mem_cgroup_cancel_charge(new_page, memcg);
 	goto out_up_write;
 }
 
@@ -2553,8 +2565,6 @@ static int khugepaged_scan_pmd(struct mm_struct *mm,
 	pmd = mm_find_pmd(mm, address);
 	if (!pmd)
 		goto out;
-	if (pmd_trans_huge(*pmd))
-		goto out;
 
 	memset(khugepaged_node_load, 0, sizeof(khugepaged_node_load));
 	pte = pte_offset_map_lock(mm, pmd, address, &ptl);
@@ -2579,6 +2589,8 @@ static int khugepaged_scan_pmd(struct mm_struct *mm,
 		 * hit record.
 		 */
 		node = page_to_nid(page);
+		if (khugepaged_scan_abort(node))
+			goto out_unmap;
 		khugepaged_node_load[node]++;
 		VM_BUG_ON_PAGE(PageCompound(page), page);
 		if (!PageLRU(page) || PageLocked(page) || !PageAnon(page))
@@ -2803,7 +2815,7 @@ static int khugepaged(void *none)
 	struct mm_slot *mm_slot;
 
 	set_freezable();
-	set_user_nice(current, 19);
+	set_user_nice(current, MAX_NICE);
 
 	while (!kthread_should_stop()) {
 		khugepaged_do_scan();
@@ -2907,12 +2919,22 @@ void split_huge_page_pmd_mm(struct mm_struct *mm, unsigned long address,
 static void split_huge_page_address(struct mm_struct *mm,
 				    unsigned long address)
 {
+	pgd_t *pgd;
+	pud_t *pud;
 	pmd_t *pmd;
 
 	VM_BUG_ON(!(address & ~HPAGE_PMD_MASK));
 
-	pmd = mm_find_pmd(mm, address);
-	if (!pmd)
+	pgd = pgd_offset(mm, address);
+	if (!pgd_present(*pgd))
+		return;
+
+	pud = pud_offset(pgd, address);
+	if (!pud_present(*pud))
+		return;
+
+	pmd = pmd_offset(pud, address);
+	if (!pmd_present(*pmd))
 		return;
 	/*
 	 * Caller holds the mmap_sem write mode, so a huge pmd cannot