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>

3 files changed, 7 insertions, 17 deletions

diff --git a/net/atm/atm_sysfs.c b/net/atm/atm_sysfs.c
index f094a08..9ef07ed 100644
--- a/net/atm/atm_sysfs.c
+++ b/net/atm/atm_sysfs.c
@@ -105,10 +105,9 @@ static struct class_device_attribute *atm_attrs[] = {
 	NULL
 };
 
-static int atm_uevent(struct class_device *cdev, char **envp, int num_envp, char *buf, int size)
+static int atm_uevent(struct class_device *cdev, struct kobj_uevent_env *env)
 {
 	struct atm_dev *adev;
-	int i = 0, len = 0;
 
 	if (!cdev)
 		return -ENODEV;
@@ -117,11 +116,9 @@ static int atm_uevent(struct class_device *cdev, char **envp, int num_envp, char
 	if (!adev)
 		return -ENODEV;
 
-	if (add_uevent_var(envp, num_envp, &i, buf, size, &len,
-			   "NAME=%s%d", adev->type, adev->number))
+	if (add_uevent_var(env, "NAME=%s%d", adev->type, adev->number))
 		return -ENOMEM;
 
-	envp[i] = NULL;
 	return 0;
 }
 
diff --git a/net/core/net-sysfs.c b/net/core/net-sysfs.c
index 909a03d..6628e45 100644
--- a/net/core/net-sysfs.c
+++ b/net/core/net-sysfs.c
@@ -396,28 +396,22 @@ static struct attribute_group wireless_group = {
 #endif /* CONFIG_SYSFS */
 
 #ifdef CONFIG_HOTPLUG
-static int netdev_uevent(struct device *d, char **envp,
-			 int num_envp, char *buf, int size)
+static int netdev_uevent(struct device *d, struct kobj_uevent_env *env)
 {
 	struct net_device *dev = to_net_dev(d);
-	int retval, len = 0, i = 0;
+	int retval;
 
 	/* pass interface to uevent. */
-	retval = add_uevent_var(envp, num_envp, &i,
-				buf, size, &len,
-				"INTERFACE=%s", dev->name);
+	retval = add_uevent_var(env, "INTERFACE=%s", dev->name);
 	if (retval)
 		goto exit;
 
 	/* pass ifindex to uevent.
 	 * ifindex is useful as it won't change (interface name may change)
 	 * and is what RtNetlink uses natively. */
-	retval = add_uevent_var(envp, num_envp, &i,
-				buf, size, &len,
-				"IFINDEX=%d", dev->ifindex);
+	retval = add_uevent_var(env, "IFINDEX=%d", dev->ifindex);
 
 exit:
-	envp[i] = NULL;
 	return retval;
 }
 #endif
diff --git a/net/wireless/sysfs.c b/net/wireless/sysfs.c
index 2d5d225..29f820e 100644
--- a/net/wireless/sysfs.c
+++ b/net/wireless/sysfs.c
@@ -53,8 +53,7 @@ static void wiphy_dev_release(struct device *dev)
 }
 
 #ifdef CONFIG_HOTPLUG
-static int wiphy_uevent(struct device *dev, char **envp,
-			int num_envp, char *buf, int size)
+static int wiphy_uevent(struct device *dev, struct kobj_uevent_env *env)
 {
 	/* TODO, we probably need stuff here */
 	return 0;