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, 7 insertions, 18 deletions

diff --git a/drivers/s390/cio/device.c b/drivers/s390/cio/device.c
index e44d92eac8e9..606bb53e9fae 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;