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/ide/ide.c b/drivers/ide/ide.c
index e96212c..a96a8b1 100644
--- a/drivers/ide/ide.c
+++ b/drivers/ide/ide.c
@@ -1663,20 +1663,13 @@
 	__ATTR_NULL
 };
 
-static int ide_uevent(struct device *dev, char **envp, int num_envp,
-		      char *buffer, int buffer_size)
+static int ide_uevent(struct device *dev, struct kobj_uevent_env *env)
 {
 	ide_drive_t *drive = to_ide_device(dev);
-	int i = 0;
-	int length = 0;
 
-	add_uevent_var(envp, num_envp, &i, buffer, buffer_size, &length,
-		       "MEDIA=%s", media_string(drive));
-	add_uevent_var(envp, num_envp, &i, buffer, buffer_size, &length,
-		       "DRIVENAME=%s", drive->name);
-	add_uevent_var(envp, num_envp, &i, buffer, buffer_size, &length,
-		       "MODALIAS=ide:m-%s", media_string(drive));
-	envp[i] = NULL;
+	add_uevent_var(env, "MEDIA=%s", media_string(drive));
+	add_uevent_var(env, "DRIVENAME=%s", drive->name);
+	add_uevent_var(env, "MODALIAS=ide:m-%s", media_string(drive));
 	return 0;
 }