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, 10 insertions, 7 deletions

diff --git a/drivers/firmware/dmi-id.c b/drivers/firmware/dmi-id.c
index 59c3b5aa89f4..2678098d4504 100644
--- a/drivers/firmware/dmi-id.c
+++ b/drivers/firmware/dmi-id.c
@@ -134,14 +134,17 @@ static struct attribute_group* sys_dmi_attribute_groups[] = {
         NULL
 };
 
-static int dmi_dev_uevent(struct device *dev, char **envp,
-                            int num_envp, char *buffer, int buffer_size)
+static int dmi_dev_uevent(struct device *dev, struct kobj_uevent_env *env)
 {
-        strcpy(buffer, "MODALIAS=");
-        get_modalias(buffer+9, buffer_size-9);
-        envp[0] = buffer;
-        envp[1] = NULL;
-
+        ssize_t len;
+
+        if (add_uevent_var(env, "MODALIAS="))
+                return -ENOMEM;
+        len = get_modalias(&env->buf[env->buflen - 1],
+                           sizeof(env->buf) - env->buflen);
+        if (len >= (sizeof(env->buf) - env->buflen))
+                return -ENOMEM;
+        env->buflen += len;
         return 0;
 }