1 files changed, 10 insertions, 39 deletions

diff --git a/mm/mmap.c b/mm/mmap.c
index 1971bfffcc03..b78e83d351d2 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -1829,6 +1829,9 @@ get_unmapped_area(struct file *file, unsigned long addr, unsigned long len,
 		 */
 		pgoff = 0;
 		get_area = shmem_get_unmapped_area;
+	} else if (IS_ENABLED(CONFIG_TRANSPARENT_HUGEPAGE)) {
+		/* Ensures that larger anonymous mappings are THP aligned. */
+		get_area = thp_get_unmapped_area;
 	}
 
 	addr = get_area(file, addr, len, pgoff, flags);
@@ -2207,42 +2210,7 @@ struct vm_area_struct *find_extend_vma_locked(struct mm_struct *mm, unsigned lon
 }
 #endif
 
-/*
- * IA64 has some horrid mapping rules: it can expand both up and down,
- * but with various special rules.
- *
- * We'll get rid of this architecture eventually, so the ugliness is
- * temporary.
- */
-#ifdef CONFIG_IA64
-static inline bool vma_expand_ok(struct vm_area_struct *vma, unsigned long addr)
-{
-	return REGION_NUMBER(addr) == REGION_NUMBER(vma->vm_start) &&
-		REGION_OFFSET(addr) < RGN_MAP_LIMIT;
-}
-
-/*
- * IA64 stacks grow down, but there's a special register backing store
- * that can grow up. Only sequentially, though, so the new address must
- * match vm_end.
- */
-static inline int vma_expand_up(struct vm_area_struct *vma, unsigned long addr)
-{
-	if (!vma_expand_ok(vma, addr))
-		return -EFAULT;
-	if (vma->vm_end != (addr & PAGE_MASK))
-		return -EFAULT;
-	return expand_upwards(vma, addr);
-}
-
-static inline bool vma_expand_down(struct vm_area_struct *vma, unsigned long addr)
-{
-	if (!vma_expand_ok(vma, addr))
-		return -EFAULT;
-	return expand_downwards(vma, addr);
-}
-
-#elif defined(CONFIG_STACK_GROWSUP)
+#if defined(CONFIG_STACK_GROWSUP)
 
 #define vma_expand_up(vma,addr) expand_upwards(vma, addr)
 #define vma_expand_down(vma, addr) (-EFAULT)
@@ -3294,10 +3262,11 @@ void exit_mmap(struct mm_struct *mm)
 	arch_exit_mmap(mm);
 
 	vma = mas_find(&mas, ULONG_MAX);
-	if (!vma) {
+	if (!vma || unlikely(xa_is_zero(vma))) {
 		/* Can happen if dup_mmap() received an OOM */
 		mmap_read_unlock(mm);
-		return;
+		mmap_write_lock(mm);
+		goto destroy;
 	}
 
 	lru_add_drain();
@@ -3332,11 +3301,13 @@ void exit_mmap(struct mm_struct *mm)
 		remove_vma(vma, true);
 		count++;
 		cond_resched();
-	} while ((vma = mas_find(&mas, ULONG_MAX)) != NULL);
+		vma = mas_find(&mas, ULONG_MAX);
+	} while (vma && likely(!xa_is_zero(vma)));
 
 	BUG_ON(count != mm->map_count);
 
 	trace_exit_mmap(mm);
+destroy:
 	__mt_destroy(&mm->mm_mt);
 	mmap_write_unlock(mm);
 	vm_unacct_memory(nr_accounted);