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>

1 files changed, 10 insertions, 23 deletions

diff --git a/sound/aoa/soundbus/core.c b/sound/aoa/soundbus/core.c
index 64d1639..f84f3e5 100644
--- a/sound/aoa/soundbus/core.c
+++ b/sound/aoa/soundbus/core.c
@@ -56,13 +56,12 @@ static int soundbus_probe(struct device *dev)
 }
 
 
-static int soundbus_uevent(struct device *dev, char **envp, int num_envp,
-			   char *buffer, int buffer_size)
+static int soundbus_uevent(struct device *dev, struct kobj_uevent_env *env)
 {
 	struct soundbus_dev * soundbus_dev;
 	struct of_device * of;
 	const char *compat;
-	int retval = 0, i = 0, length = 0;
+	int retval = 0;
 	int cplen, seen = 0;
 
 	if (!dev)
@@ -75,15 +74,11 @@ static int soundbus_uevent(struct device *dev, char **envp, int num_envp,
 	of = &soundbus_dev->ofdev;
 
 	/* stuff we want to pass to /sbin/hotplug */
-	retval = add_uevent_var(envp, num_envp, &i,
-				buffer, buffer_size, &length,
-				"OF_NAME=%s", of->node->name);
+	retval = add_uevent_var(env, "OF_NAME=%s", of->node->name);
 	if (retval)
 		return retval;
 
-	retval = add_uevent_var(envp, num_envp, &i,
-				buffer, buffer_size, &length,
-				"OF_TYPE=%s", of->node->type);
+	retval = add_uevent_var(env, "OF_TYPE=%s", of->node->type);
 	if (retval)
 		return retval;
 
@@ -93,27 +88,19 @@ static int soundbus_uevent(struct device *dev, char **envp, int num_envp,
 
 	compat = of_get_property(of->node, "compatible", &cplen);
 	while (compat && cplen > 0) {
-		int tmp = length;
-		retval = add_uevent_var(envp, num_envp, &i,
-					buffer, buffer_size, &length,
-					"OF_COMPATIBLE_%d=%s", seen, compat);
+		int tmp = env->buflen;
+		retval = add_uevent_var(env, "OF_COMPATIBLE_%d=%s", seen, compat);
 		if (retval)
 			return retval;
-		compat += length - tmp;
-		cplen -= length - tmp;
+		compat += env->buflen - tmp;
+		cplen -= env->buflen - tmp;
 		seen += 1;
 	}
 
-	retval = add_uevent_var(envp, num_envp, &i,
-				buffer, buffer_size, &length,
-				"OF_COMPATIBLE_N=%d", seen);
+	retval = add_uevent_var(env, "OF_COMPATIBLE_N=%d", seen);
 	if (retval)
 		return retval;
-	retval = add_uevent_var(envp, num_envp, &i,
-				buffer, buffer_size, &length,
-				"MODALIAS=%s", soundbus_dev->modalias);
-
-	envp[i] = NULL;
+	retval = add_uevent_var(env, "MODALIAS=%s", soundbus_dev->modalias);
 
 	return retval;
 }