[PATCH] driver core: fix built-in drivers sysfs links

built-in drivers had broken sysfs links that caused bootup hangs for
certain driver unregistry sequences.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Acked-by: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg KH <greg@kroah.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/include/linux/device.h b/include/linux/device.h
index caad9bb..5cf30e9 100644 (file)
--- a/include/linux/device.h
+++ b/include/linux/device.h
@@ -128,6 +128,7 @@ struct device_driver {
 
        struct module           * owner;
        const char              * mod_name;     /* used for built-in modules */
+       struct module_kobject   * mkobj;
 
        int     (*probe)        (struct device * dev);
        int     (*remove)       (struct device * dev);

diff --git a/kernel/module.c b/kernel/module.c
index fbc51de..dcdb32b 100644 (file)
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -2384,8 +2384,13 @@ void module_add_driver(struct module *mod, struct device_driver *drv)
 
                /* Lookup built-in module entry in /sys/modules */
                mkobj = kset_find_obj(&module_subsys.kset, drv->mod_name);
-               if (mkobj)
+               if (mkobj) {
                        mk = container_of(mkobj, struct module_kobject, kobj);
+                       /* remember our module structure */
+                       drv->mkobj = mk;
+                       /* kset_find_obj took a reference */
+                       kobject_put(mkobj);
+               }
        }
 
        if (!mk)
@@ -2405,17 +2410,22 @@ EXPORT_SYMBOL(module_add_driver);
 
 void module_remove_driver(struct device_driver *drv)
 {
+       struct module_kobject *mk = NULL;
        char *driver_name;
 
        if (!drv)
                return;
 
        sysfs_remove_link(&drv->kobj, "module");
-       if (drv->owner && drv->owner->mkobj.drivers_dir) {
+
+       if (drv->owner)
+               mk = &drv->owner->mkobj;
+       else if (drv->mkobj)
+               mk = drv->mkobj;
+       if (mk && mk->drivers_dir) {
                driver_name = make_driver_name(drv);
                if (driver_name) {
-                       sysfs_remove_link(drv->owner->mkobj.drivers_dir,
-                                         driver_name);
+                       sysfs_remove_link(mk->drivers_dir, driver_name);
                        kfree(driver_name);
                }
        }