1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * module.c - module sysfs fun for drivers 4 */ 5 #include <linux/device.h> 6 #include <linux/module.h> 7 #include <linux/errno.h> 8 #include <linux/slab.h> 9 #include <linux/string.h> 10 #include <linux/rcupdate.h> 11 #include "base.h" 12 13 static char *make_driver_name(const struct device_driver *drv) 14 { 15 char *driver_name; 16 17 driver_name = kasprintf(GFP_KERNEL, "%s:%s", drv->bus->name, drv->name); 18 if (!driver_name) 19 return NULL; 20 21 return driver_name; 22 } 23 24 static void module_create_drivers_dir(struct module_kobject *mk) 25 { 26 static DEFINE_MUTEX(drivers_dir_mutex); 27 28 mutex_lock(&drivers_dir_mutex); 29 if (mk && !mk->drivers_dir) 30 mk->drivers_dir = kobject_create_and_add("drivers", &mk->kobj); 31 mutex_unlock(&drivers_dir_mutex); 32 } 33 34 int module_add_driver(struct module *mod, const struct device_driver *drv) 35 { 36 char *driver_name; 37 struct module_kobject *mk = NULL; 38 int ret; 39 40 if (!drv) 41 return 0; 42 43 if (mod) 44 mk = &mod->mkobj; 45 else if (drv->mod_name) { 46 struct kobject *mkobj; 47 48 /* Lookup built-in module entry in /sys/modules */ 49 mkobj = kset_find_obj(module_kset, drv->mod_name); 50 if (mkobj) { 51 mk = container_of(mkobj, struct module_kobject, kobj); 52 /* remember our module structure */ 53 drv->p->mkobj = mk; 54 /* kset_find_obj took a reference */ 55 kobject_put(mkobj); 56 } 57 } 58 59 if (!mk) 60 return 0; 61 62 ret = sysfs_create_link(&drv->p->kobj, &mk->kobj, "module"); 63 if (ret) 64 return ret; 65 66 driver_name = make_driver_name(drv); 67 if (!driver_name) { 68 ret = -ENOMEM; 69 goto out; 70 } 71 72 module_create_drivers_dir(mk); 73 if (!mk->drivers_dir) { 74 ret = -EINVAL; 75 goto out; 76 } 77 78 ret = sysfs_create_link(mk->drivers_dir, &drv->p->kobj, driver_name); 79 if (ret) 80 goto out; 81 82 kfree(driver_name); 83 84 return 0; 85 out: 86 sysfs_remove_link(&drv->p->kobj, "module"); 87 sysfs_remove_link(mk->drivers_dir, driver_name); 88 kfree(driver_name); 89 90 return ret; 91 } 92 93 void module_remove_driver(const struct device_driver *drv) 94 { 95 struct module_kobject *mk = NULL; 96 char *driver_name; 97 98 if (!drv) 99 return; 100 101 /* Synchronize with dev_uevent() */ 102 synchronize_rcu(); 103 104 sysfs_remove_link(&drv->p->kobj, "module"); 105 106 if (drv->owner) 107 mk = &drv->owner->mkobj; 108 else if (drv->p->mkobj) 109 mk = drv->p->mkobj; 110 if (mk && mk->drivers_dir) { 111 driver_name = make_driver_name(drv); 112 if (driver_name) { 113 sysfs_remove_link(mk->drivers_dir, driver_name); 114 kfree(driver_name); 115 } 116 } 117 } 118