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, 12 insertions, 30 deletions

diff --git a/drivers/s390/cio/ccwgroup.c b/drivers/s390/cio/ccwgroup.c
index b0a18f5176a..5d967c43982 100644
--- a/drivers/s390/cio/ccwgroup.c
+++ b/drivers/s390/cio/ccwgroup.c
@@ -44,8 +44,7 @@ ccwgroup_bus_match (struct device * dev, struct device_driver * drv)
 	return 0;
 }
 static int
-ccwgroup_uevent (struct device *dev, char **envp, int num_envp, char *buffer,
-		  int buffer_size)
+ccwgroup_uevent (struct device *dev, struct kobj_uevent_env *env)
 {
 	/* TODO */
 	return 0;
diff --git a/drivers/s390/cio/device.c b/drivers/s390/cio/device.c
index e44d92eac8e..606bb53e9fa 100644
--- a/drivers/s390/cio/device.c
+++ b/drivers/s390/cio/device.c
@@ -78,49 +78,38 @@ static int snprint_alias(char *buf, size_t size,
 
 /* Set up environment variables for ccw device uevent. Return 0 on success,
  * non-zero otherwise. */
-static int ccw_uevent(struct device *dev, char **envp, int num_envp,
-		      char *buffer, int buffer_size)
+static int ccw_uevent(struct device *dev, struct kobj_uevent_env *env)
 {
 	struct ccw_device *cdev = to_ccwdev(dev);
 	struct ccw_device_id *id = &(cdev->id);
-	int i = 0;
-	int len = 0;
 	int ret;
 	char modalias_buf[30];
 
 	/* CU_TYPE= */
-	ret = add_uevent_var(envp, num_envp, &i, buffer, buffer_size, &len,
-			     "CU_TYPE=%04X", id->cu_type);
+	ret = add_uevent_var(env, "CU_TYPE=%04X", id->cu_type);
 	if (ret)
 		return ret;
 
 	/* CU_MODEL= */
-	ret = add_uevent_var(envp, num_envp, &i, buffer, buffer_size, &len,
-			     "CU_MODEL=%02X", id->cu_model);
+	ret = add_uevent_var(env, "CU_MODEL=%02X", id->cu_model);
 	if (ret)
 		return ret;
 
 	/* The next two can be zero, that's ok for us */
 	/* DEV_TYPE= */
-	ret = add_uevent_var(envp, num_envp, &i, buffer, buffer_size, &len,
-			     "DEV_TYPE=%04X", id->dev_type);
+	ret = add_uevent_var(env, "DEV_TYPE=%04X", id->dev_type);
 	if (ret)
 		return ret;
 
 	/* DEV_MODEL= */
-	ret = add_uevent_var(envp, num_envp, &i, buffer, buffer_size, &len,
-			     "DEV_MODEL=%02X", id->dev_model);
+	ret = add_uevent_var(env, "DEV_MODEL=%02X", id->dev_model);
 	if (ret)
 		return ret;
 
 	/* MODALIAS=  */
 	snprint_alias(modalias_buf, sizeof(modalias_buf), id, "");
-	ret = add_uevent_var(envp, num_envp, &i, buffer, buffer_size, &len,
-			     "MODALIAS=%s", modalias_buf);
-	if (ret)
-		return ret;
-	envp[i] = NULL;
-	return 0;
+	ret = add_uevent_var(env, "MODALIAS=%s", modalias_buf);
+	return ret;
 }
 
 struct bus_type ccw_bus_type;
diff --git a/drivers/s390/crypto/ap_bus.c b/drivers/s390/crypto/ap_bus.c
index 90bd2201451..e9971304159 100644
--- a/drivers/s390/crypto/ap_bus.c
+++ b/drivers/s390/crypto/ap_bus.c
@@ -458,28 +458,22 @@ static int ap_bus_match(struct device *dev, struct device_driver *drv)
  * uevent function for AP devices. It sets up a single environment
  * variable DEV_TYPE which contains the hardware device type.
  */
-static int ap_uevent (struct device *dev, char **envp, int num_envp,
-		       char *buffer, int buffer_size)
+static int ap_uevent (struct device *dev, struct kobj_uevent_env *env)
 {
 	struct ap_device *ap_dev = to_ap_dev(dev);
-	int retval = 0, length = 0, i = 0;
+	int retval = 0;
 
 	if (!ap_dev)
 		return -ENODEV;
 
 	/* Set up DEV_TYPE environment variable. */
-	retval = add_uevent_var(envp, num_envp, &i,
-				buffer, buffer_size, &length,
-				"DEV_TYPE=%04X", ap_dev->device_type);
+	retval = add_uevent_var(env, "DEV_TYPE=%04X", ap_dev->device_type);
 	if (retval)
 		return retval;
 
 	/* Add MODALIAS= */
-	retval = add_uevent_var(envp, num_envp, &i,
-				buffer, buffer_size, &length,
-				"MODALIAS=ap:t%02X", ap_dev->device_type);
+	retval = add_uevent_var(env, "MODALIAS=ap:t%02X", ap_dev->device_type);
 
-	envp[i] = NULL;
 	return retval;
 }