1 files changed, 4 insertions, 0 deletions

diff --git a/drivers/char/mem.c b/drivers/char/mem.c
index e985b1c2730e..1256454b2d43 100644
--- a/drivers/char/mem.c
+++ b/drivers/char/mem.c
@@ -876,6 +876,10 @@ static int memory_open(struct inode *inode, struct file *filp)
         if (dev->dev_info)
                 filp->f_mapping->backing_dev_info = dev->dev_info;
 
+        /* Is /dev/mem or /dev/kmem ? */
+        if (dev->dev_info == &directly_mappable_cdev_bdi)
+                filp->f_mode |= FMODE_UNSIGNED_OFFSET;
+
         if (dev->fops->open)
                 return dev->fops->open(inode, filp);