s390: fix race in device_create

There is a race from when a device is created with device_create() and
then the drvdata is set with a call to dev_set_drvdata() in which a
sysfs file could be open, yet the drvdata will be NULL, causing all
sorts of bad things to happen.

This patch fixes the problem by using the new function,
device_create_drvdata().

Cc: Kay Sievers <kay.sievers@vrfy.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 4 insertions, 5 deletions

diff --git a/drivers/s390/char/vmlogrdr.c b/drivers/s390/char/vmlogrdr.c
index e8487347e4d4..2c2428cc05d8 100644
--- a/drivers/s390/char/vmlogrdr.c
+++ b/drivers/s390/char/vmlogrdr.c
@@ -762,10 +762,10 @@ static int vmlogrdr_register_device(struct vmlogrdr_priv_t *priv)
                 device_unregister(dev);
                 return ret;
         }
-        priv->class_device = device_create(vmlogrdr_class, dev,
-                                           MKDEV(vmlogrdr_major,
-                                                 priv->minor_num),
-                                           "%s", dev->bus_id);
+        priv->class_device = device_create_drvdata(vmlogrdr_class, dev,
+                                                   MKDEV(vmlogrdr_major,
+                                                         priv->minor_num),
+                                                   priv, "%s", dev->bus_id);
         if (IS_ERR(priv->class_device)) {
                 ret = PTR_ERR(priv->class_device);
                 priv->class_device=NULL;
@@ -773,7 +773,6 @@ static int vmlogrdr_register_device(struct vmlogrdr_priv_t *priv)
                 device_unregister(dev);
                 return ret;
         }
-        dev->driver_data = priv;
         priv->device = dev;
         return 0;
 }