1 files changed, 71 insertions, 20 deletions

diff --git a/kernel/module.c b/kernel/module.c
index d0f2260a021..f77e893e462 100644
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -537,6 +537,8 @@ static int already_uses(struct module *a, struct module *b)
 static int use_module(struct module *a, struct module *b)
 {
 	struct module_use *use;
+	int no_warn;
+
 	if (b == NULL || already_uses(a, b)) return 1;
 
 	if (!strong_try_module_get(b))
@@ -552,6 +554,7 @@ static int use_module(struct module *a, struct module *b)
 
 	use->module_which_uses = a;
 	list_add(&use->list, &b->modules_which_use_me);
+	no_warn = sysfs_create_link(b->holders_dir, &a->mkobj.kobj, a->name);
 	return 1;
 }
 
@@ -569,6 +572,7 @@ static void module_unload_free(struct module *mod)
 				module_put(i);
 				list_del(&use->list);
 				kfree(use);
+				sysfs_remove_link(i->holders_dir, mod->name);
 				/* There can be at most one match. */
 				break;
 			}
@@ -1064,7 +1068,8 @@ static inline void remove_sect_attrs(struct module *mod)
 }
 #endif /* CONFIG_KALLSYMS */
 
-static int module_add_modinfo_attrs(struct module *mod)
+#ifdef CONFIG_SYSFS
+int module_add_modinfo_attrs(struct module *mod)
 {
 	struct module_attribute *attr;
 	struct module_attribute *temp_attr;
@@ -1090,7 +1095,7 @@ static int module_add_modinfo_attrs(struct module *mod)
 	return error;
 }
 
-static void module_remove_modinfo_attrs(struct module *mod)
+void module_remove_modinfo_attrs(struct module *mod)
 {
 	struct module_attribute *attr;
 	int i;
@@ -1105,10 +1110,10 @@ static void module_remove_modinfo_attrs(struct module *mod)
 	}
 	kfree(mod->modinfo_attrs);
 }
+#endif
 
-static int mod_sysfs_setup(struct module *mod,
-			   struct kernel_param *kparam,
-			   unsigned int num_params)
+#ifdef CONFIG_SYSFS
+int mod_sysfs_init(struct module *mod)
 {
 	int err;
 
@@ -1125,21 +1130,30 @@ static int mod_sysfs_setup(struct module *mod,
 	kobj_set_kset_s(&mod->mkobj, module_subsys);
 	mod->mkobj.mod = mod;
 
-	/* delay uevent until full sysfs population */
 	kobject_init(&mod->mkobj.kobj);
+
+out:
+	return err;
+}
+
+int mod_sysfs_setup(struct module *mod,
+			   struct kernel_param *kparam,
+			   unsigned int num_params)
+{
+	int err;
+
+	/* delay uevent until full sysfs population */
 	err = kobject_add(&mod->mkobj.kobj);
 	if (err)
 		goto out;
 
-	mod->drivers_dir = kobject_add_dir(&mod->mkobj.kobj, "drivers");
-	if (!mod->drivers_dir) {
-		err = -ENOMEM;
+	mod->holders_dir = kobject_add_dir(&mod->mkobj.kobj, "holders");
+	if (!mod->holders_dir)
 		goto out_unreg;
-	}
 
 	err = module_param_sysfs_setup(mod, kparam, num_params);
 	if (err)
-		goto out_unreg_drivers;
+		goto out_unreg_holders;
 
 	err = module_add_modinfo_attrs(mod);
 	if (err)
@@ -1150,21 +1164,22 @@ static int mod_sysfs_setup(struct module *mod,
 
 out_unreg_param:
 	module_param_sysfs_remove(mod);
-out_unreg_drivers:
-	kobject_unregister(mod->drivers_dir);
+out_unreg_holders:
+	kobject_unregister(mod->holders_dir);
 out_unreg:
 	kobject_del(&mod->mkobj.kobj);
 	kobject_put(&mod->mkobj.kobj);
 out:
 	return err;
 }
+#endif
 
 static void mod_kobject_remove(struct module *mod)
 {
 	module_remove_modinfo_attrs(mod);
 	module_param_sysfs_remove(mod);
-	kobject_unregister(mod->drivers_dir);
-
+	kobject_unregister(mod->mkobj.drivers_dir);
+	kobject_unregister(mod->holders_dir);
 	kobject_unregister(&mod->mkobj.kobj);
 }
 
@@ -1768,6 +1783,10 @@ static struct module *load_module(void __user *umod,
 	/* Now we've moved module, initialize linked lists, etc. */
 	module_unload_init(mod);
 
+	/* Initialize kobject, so we can reference it. */
+	if (mod_sysfs_init(mod) != 0)
+		goto cleanup;
+
 	/* Set up license info based on the info section */
 	set_license(mod, get_modinfo(sechdrs, infoindex, "license"));
 
@@ -2327,6 +2346,7 @@ void print_modules(void)
 	printk("\n");
 }
 
+#ifdef CONFIG_SYSFS
 static char *make_driver_name(struct device_driver *drv)
 {
 	char *driver_name;
@@ -2340,19 +2360,43 @@ static char *make_driver_name(struct device_driver *drv)
 	return driver_name;
 }
 
+static void module_create_drivers_dir(struct module_kobject *mk)
+{
+	if (!mk || mk->drivers_dir)
+		return;
+
+	mk->drivers_dir = kobject_add_dir(&mk->kobj, "drivers");
+}
+
 void module_add_driver(struct module *mod, struct device_driver *drv)
 {
 	char *driver_name;
 	int no_warn;
+	struct module_kobject *mk = NULL;
 
-	if (!mod || !drv)
+	if (!drv)
+		return;
+
+	if (mod)
+		mk = &mod->mkobj;
+	else if (drv->mod_name) {
+		struct kobject *mkobj;
+
+		/* Lookup built-in module entry in /sys/modules */
+		mkobj = kset_find_obj(&module_subsys.kset, drv->mod_name);
+		if (mkobj)
+			mk = container_of(mkobj, struct module_kobject, kobj);
+	}
+
+	if (!mk)
 		return;
 
 	/* Don't check return codes; these calls are idempotent */
-	no_warn = sysfs_create_link(&drv->kobj, &mod->mkobj.kobj, "module");
+	no_warn = sysfs_create_link(&drv->kobj, &mk->kobj, "module");
 	driver_name = make_driver_name(drv);
 	if (driver_name) {
-		no_warn = sysfs_create_link(mod->drivers_dir, &drv->kobj,
+		module_create_drivers_dir(mk);
+		no_warn = sysfs_create_link(mk->drivers_dir, &drv->kobj,
 					    driver_name);
 		kfree(driver_name);
 	}
@@ -2367,16 +2411,23 @@ void module_remove_driver(struct device_driver *drv)
 		return;
 
 	sysfs_remove_link(&drv->kobj, "module");
-	if (drv->owner && drv->owner->drivers_dir) {
+	if (drv->owner && drv->owner->mkobj.drivers_dir) {
 		driver_name = make_driver_name(drv);
 		if (driver_name) {
-			sysfs_remove_link(drv->owner->drivers_dir,
+			sysfs_remove_link(drv->owner->mkobj.drivers_dir,
 					  driver_name);
 			kfree(driver_name);
 		}
 	}
+	/*
+	 * Undo the additional reference we added in module_add_driver()
+	 * via kset_find_obj()
+	 */
+	if (drv->mod_name)
+		kobject_put(&drv->kobj);
 }
 EXPORT_SYMBOL(module_remove_driver);
+#endif
 
 #ifdef CONFIG_MODVERSIONS
 /* Generate the signature for struct module here, too, for modversions. */