Driver core: change add_uevent_var to use a struct

This changes the uevent buffer functions to use a struct instead of a
long list of parameters. It does no longer require the caller to do the
proper buffer termination and size accounting, which is currently wrong
in some places. It fixes a known bug where parts of the uevent
environment are overwritten because of wrong index calculations.

Many thanks to Mathieu Desnoyers for finding bugs and improving the
error handling.

Signed-off-by: Kay Sievers <kay.sievers@vrfy.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Cc: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>


diff --git a/drivers/infiniband/core/sysfs.c b/drivers/infiniband/core/sysfs.c
index 70b77ae..3d40506 100644
--- a/drivers/infiniband/core/sysfs.c
+++ b/drivers/infiniband/core/sysfs.c
@@ -434,21 +434,18 @@
 	kfree(dev);
 }
 
-static int ib_device_uevent(struct class_device *cdev, char **envp,
-			    int num_envp, char *buf, int size)
+static int ib_device_uevent(struct class_device *cdev,
+			    struct kobj_uevent_env *env)
 {
 	struct ib_device *dev = container_of(cdev, struct ib_device, class_dev);
-	int i = 0, len = 0;
 
-	if (add_uevent_var(envp, num_envp, &i, buf, size, &len,
-			   "NAME=%s", dev->name))
+	if (add_uevent_var(env, "NAME=%s", dev->name))
 		return -ENOMEM;
 
 	/*
 	 * It would be nice to pass the node GUID with the event...
 	 */
 
-	envp[i] = NULL;
 	return 0;
 }