[MM]: PTRS_PER_{PUD,PMD} are not necessarily compile time constants.

Signed-off-by: David S. Miller <davem@davemloft.net>

mm/memory.c

@@ -2089,7 +2089,6 @@ int handle_mm_fault(struct mm_struct *mm, struct vm_area_struct * vma,
 }
 
 #ifndef __ARCH_HAS_4LEVEL_HACK
-#if (PTRS_PER_PUD > 1)
 /*
  * Allocate page upper directory.
  *
@@ -2101,6 +2100,7 @@ int handle_mm_fault(struct mm_struct *mm, struct vm_area_struct * vma,
  */
 pud_t fastcall *__pud_alloc(struct mm_struct *mm, pgd_t *pgd, unsigned long address)
 {
+	if (PTRS_PER_PUD > 1) {
 		pud_t *new;
 
 		spin_unlock(&mm->page_table_lock);
@@ -2118,12 +2118,12 @@ pud_t fastcall *__pud_alloc(struct mm_struct *mm, pgd_t *pgd, unsigned long addr
 			goto out;
 		}
 		pgd_populate(mm, pgd, new);
-out:
+	out:
 		return pud_offset(pgd, address);
+	}
+	return NULL;
 }
-#endif
 
-#if (PTRS_PER_PMD > 1)
 /*
  * Allocate page middle directory.
  *
@@ -2135,6 +2135,7 @@ pud_t fastcall *__pud_alloc(struct mm_struct *mm, pgd_t *pgd, unsigned long addr
  */
 pmd_t fastcall *__pmd_alloc(struct mm_struct *mm, pud_t *pud, unsigned long address)
 {
+	if (PTRS_PER_PMD > 1) {
 		pmd_t *new;
 
 		spin_unlock(&mm->page_table_lock);
@@ -2152,10 +2153,11 @@ pmd_t fastcall *__pmd_alloc(struct mm_struct *mm, pud_t *pud, unsigned long addr
 			goto out;
 		}
 		pud_populate(mm, pud, new);
-out:
+	out:
 		return pmd_offset(pud, address);
+	}
+	return NULL;
 }
-#endif
 #else
 pmd_t fastcall *__pmd_alloc(struct mm_struct *mm, pud_t *pud, unsigned long address)
 {