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