1 files changed, 43 insertions, 7 deletions

diff --git a/tools/testing/vma/vma_internal.h b/tools/testing/vma/vma_internal.h
index 4505b1c31be1..816e7e057585 100644
--- a/tools/testing/vma/vma_internal.h
+++ b/tools/testing/vma/vma_internal.h
@@ -159,6 +159,14 @@ typedef __bitwise unsigned int vm_fault_t;
 
 #define ASSERT_EXCLUSIVE_WRITER(x)
 
+/**
+ * swap - swap values of @a and @b
+ * @a: first value
+ * @b: second value
+ */
+#define swap(a, b) \
+	do { typeof(a) __tmp = (a); (a) = (b); (b) = __tmp; } while (0)
+
 struct kref {
 	refcount_t refcount;
 };
@@ -1434,8 +1442,29 @@ static inline void free_anon_vma_name(struct vm_area_struct *vma)
 	(void)vma;
 }
 
+/* Declared in vma.h. */
+static inline void set_vma_from_desc(struct vm_area_struct *vma,
+		struct vm_area_desc *desc);
+
+static inline struct vm_area_desc *vma_to_desc(struct vm_area_struct *vma,
+		struct vm_area_desc *desc);
+
+static int compat_vma_mmap_prepare(struct file *file,
+		struct vm_area_struct *vma)
+{
+	struct vm_area_desc desc;
+	int err;
+
+	err = file->f_op->mmap_prepare(vma_to_desc(vma, &desc));
+	if (err)
+		return err;
+	set_vma_from_desc(vma, &desc);
+
+	return 0;
+}
+
 /* Did the driver provide valid mmap hook configuration? */
-static inline bool file_has_valid_mmap_hooks(struct file *file)
+static inline bool can_mmap_file(struct file *file)
 {
 	bool has_mmap = file->f_op->mmap;
 	bool has_mmap_prepare = file->f_op->mmap_prepare;
@@ -1443,22 +1472,21 @@ static inline bool file_has_valid_mmap_hooks(struct file *file)
 	/* Hooks are mutually exclusive. */
 	if (WARN_ON_ONCE(has_mmap && has_mmap_prepare))
 		return false;
-	if (WARN_ON_ONCE(!has_mmap && !has_mmap_prepare))
+	if (!has_mmap && !has_mmap_prepare)
 		return false;
 
 	return true;
 }
 
-static inline int call_mmap(struct file *file, struct vm_area_struct *vma)
+static inline int vfs_mmap(struct file *file, struct vm_area_struct *vma)
 {
-	if (WARN_ON_ONCE(file->f_op->mmap_prepare))
-		return -EINVAL;
+	if (file->f_op->mmap_prepare)
+		return compat_vma_mmap_prepare(file, vma);
 
 	return file->f_op->mmap(file, vma);
 }
 
-static inline int __call_mmap_prepare(struct file *file,
-		struct vm_area_desc *desc)
+static inline int vfs_mmap_prepare(struct file *file, struct vm_area_desc *desc)
 {
 	return file->f_op->mmap_prepare(desc);
 }
@@ -1468,4 +1496,12 @@ static inline void fixup_hugetlb_reservations(struct vm_area_struct *vma)
 	(void)vma;
 }
 
+static inline void vma_set_file(struct vm_area_struct *vma, struct file *file)
+{
+	/* Changing an anonymous vma with this is illegal */
+	get_file(file);
+	swap(vma->vm_file, file);
+	fput(file);
+}
+
 #endif	/* __MM_VMA_INTERNAL_H */