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 b0a18f5176..5d967c4398 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 e44d92eac8..606bb53e9f 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 90bd220145..e997130415 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;
 }