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>

2 files changed, 6 insertions, 14 deletions

diff --git a/drivers/power/power_supply.h b/drivers/power/power_supply.h
index a9880d4..f38ba48 100644
--- a/drivers/power/power_supply.h
+++ b/drivers/power/power_supply.h
@@ -14,8 +14,7 @@
 
 extern int power_supply_create_attrs(struct power_supply *psy);
 extern void power_supply_remove_attrs(struct power_supply *psy);
-extern int power_supply_uevent(struct device *dev, char **envp, int num_envp,
-			       char *buffer, int buffer_size);
+extern int power_supply_uevent(struct device *dev, struct kobj_uevent_env *env);
 
 #else
 
diff --git a/drivers/power/power_supply_sysfs.c b/drivers/power/power_supply_sysfs.c
index de3155b..249f61b 100644
--- a/drivers/power/power_supply_sysfs.c
+++ b/drivers/power/power_supply_sysfs.c
@@ -195,11 +195,10 @@ static char *kstruprdup(const char *str, gfp_t gfp)
 	return ret;
 }
 
-int power_supply_uevent(struct device *dev, char **envp, int num_envp,
-			char *buffer, int buffer_size)
+int power_supply_uevent(struct device *dev, struct kobj_uevent_env *env)
 {
 	struct power_supply *psy = dev_get_drvdata(dev);
-	int i = 0, length = 0, ret = 0, j;
+	int ret = 0, j;
 	char *prop_buf;
 	char *attrname;
 
@@ -212,8 +211,7 @@ int power_supply_uevent(struct device *dev, char **envp, int num_envp,
 
 	dev_dbg(dev, "POWER_SUPPLY_NAME=%s\n", psy->name);
 
-	ret = add_uevent_var(envp, num_envp, &i, buffer, buffer_size,
-			     &length, "POWER_SUPPLY_NAME=%s", psy->name);
+	ret = add_uevent_var(env, "POWER_SUPPLY_NAME=%s", psy->name);
 	if (ret)
 		return ret;
 
@@ -243,9 +241,7 @@ int power_supply_uevent(struct device *dev, char **envp, int num_envp,
 
 		dev_dbg(dev, "Static prop %s=%s\n", attrname, prop_buf);
 
-		ret = add_uevent_var(envp, num_envp, &i, buffer, buffer_size,
-				     &length, "POWER_SUPPLY_%s=%s",
-				     attrname, prop_buf);
+		ret = add_uevent_var(env, "POWER_SUPPLY_%s=%s", attrname, prop_buf);
 		kfree(attrname);
 		if (ret)
 			goto out;
@@ -282,14 +278,11 @@ int power_supply_uevent(struct device *dev, char **envp, int num_envp,
 
 		dev_dbg(dev, "prop %s=%s\n", attrname, prop_buf);
 
-		ret = add_uevent_var(envp, num_envp, &i, buffer, buffer_size,
-				     &length, "POWER_SUPPLY_%s=%s",
-				     attrname, prop_buf);
+		ret = add_uevent_var(env, "POWER_SUPPLY_%s=%s", attrname, prop_buf);
 		kfree(attrname);
 		if (ret)
 			goto out;
 	}
-	envp[i] = NULL;
 
 out:
 	free_page((unsigned long)prop_buf);