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, 3 insertions, 13 deletions

diff --git a/arch/powerpc/kernel/vio.c b/arch/powerpc/kernel/vio.c
index cb22a3557c4e..19a5656001c0 100644
--- a/arch/powerpc/kernel/vio.c
+++ b/arch/powerpc/kernel/vio.c
@@ -317,30 +317,20 @@ static int vio_bus_match(struct device *dev, struct device_driver *drv)
         return (ids != NULL) && (vio_match_device(ids, vio_dev) != NULL);
 }
 
-static int vio_hotplug(struct device *dev, char **envp, int num_envp,
-                        char *buffer, int buffer_size)
+static int vio_hotplug(struct device *dev, struct kobj_uevent_env *env)
 {
         const struct vio_dev *vio_dev = to_vio_dev(dev);
         struct device_node *dn;
         const char *cp;
-        int length;
-
-        if (!num_envp)
-                return -ENOMEM;
 
         dn = dev->archdata.of_node;
         if (!dn)
                 return -ENODEV;
-        cp = of_get_property(dn, "compatible", &length);
+        cp = of_get_property(dn, "compatible", NULL);
         if (!cp)
                 return -ENODEV;
 
-        envp[0] = buffer;
-        length = scnprintf(buffer, buffer_size, "MODALIAS=vio:T%sS%s",
-                                vio_dev->type, cp);
-        if ((buffer_size - length) <= 0)
-                return -ENOMEM;
-        envp[1] = NULL;
+        add_uevent_var(env, "MODALIAS=vio:T%sS%s", vio_dev->type, cp);
         return 0;
 }