1 files changed, 34 insertions, 22 deletions

diff --git a/drivers/mtd/mtdchar.c b/drivers/mtd/mtdchar.c
index 9f8658e..72b788e 100644
--- a/drivers/mtd/mtdchar.c
+++ b/drivers/mtd/mtdchar.c
@@ -1064,6 +1064,33 @@ static unsigned long mtd_get_unmapped_area(struct file *file,
 }
 #endif
 
+static inline unsigned long get_vm_size(struct vm_area_struct *vma)
+{
+	return vma->vm_end - vma->vm_start;
+}
+
+static inline resource_size_t get_vm_offset(struct vm_area_struct *vma)
+{
+	return (resource_size_t) vma->vm_pgoff << PAGE_SHIFT;
+}
+
+/*
+ * Set a new vm offset.
+ *
+ * Verify that the incoming offset really works as a page offset,
+ * and that the offset and size fit in a resource_size_t.
+ */
+static inline int set_vm_offset(struct vm_area_struct *vma, resource_size_t off)
+{
+	pgoff_t pgoff = off >> PAGE_SHIFT;
+	if (off != (resource_size_t) pgoff << PAGE_SHIFT)
+		return -EINVAL;
+	if (off + get_vm_size(vma) - 1 < off)
+		return -EINVAL;
+	vma->vm_pgoff = pgoff;
+	return 0;
+}
+
 /*
  * set up a mapping for shared memory segments
  */
@@ -1073,32 +1100,17 @@ static int mtd_mmap(struct file *file, struct vm_area_struct *vma)
 	struct mtd_file_info *mfi = file->private_data;
 	struct mtd_info *mtd = mfi->mtd;
 	struct map_info *map = mtd->priv;
-	unsigned long start;
-	unsigned long off;
-	u32 len;
-
-	if (mtd->type == MTD_RAM || mtd->type == MTD_ROM) {
-		off = vma->vm_pgoff << PAGE_SHIFT;
-		start = map->phys;
-		len = PAGE_ALIGN((start & ~PAGE_MASK) + map->size);
-		start &= PAGE_MASK;
-		if ((vma->vm_end - vma->vm_start + off) > len)
-			return -EINVAL;
-
-		off += start;
-		vma->vm_pgoff = off >> PAGE_SHIFT;
-		vma->vm_flags |= VM_IO | VM_RESERVED;
 
+        /* This is broken because it assumes the MTD device is map-based
+	   and that mtd->priv is a valid struct map_info.  It should be
+	   replaced with something that uses the mtd_get_unmapped_area()
+	   operation properly. */
+	if (0 /*mtd->type == MTD_RAM || mtd->type == MTD_ROM*/) {
 #ifdef pgprot_noncached
-		if (file->f_flags & O_DSYNC || off >= __pa(high_memory))
+		if (file->f_flags & O_DSYNC || map->phys >= __pa(high_memory))
 			vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
 #endif
-		if (io_remap_pfn_range(vma, vma->vm_start, off >> PAGE_SHIFT,
-				       vma->vm_end - vma->vm_start,
-				       vma->vm_page_prot))
-			return -EAGAIN;
-
-		return 0;
+		return vm_iomap_memory(vma, map->phys, map->size);
 	}
 	return -ENOSYS;
 #else