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
12static char *make_driver_name(const struct device_driver *drv)
13{
14 char *driver_name;
15
16 driver_name = kasprintf(GFP_KERNEL, fmt: "%s:%s", drv->bus->name, drv->name);
17 if (!driver_name)
18 return NULL;
19
20 return driver_name;
21}
22
23static 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(name: "drivers", parent: &mk->kobj);
30 mutex_unlock(lock: &drivers_dir_mutex);
31}
32
33int module_add_driver(struct module *mod, const 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 /* Lookup or create built-in module entry in /sys/modules */
46 mk = lookup_or_create_module_kobject(name: drv->mod_name);
47 if (mk) {
48 /* remember our module structure */
49 drv->p->mkobj = mk;
50 /* lookup_or_create_module_kobject took a reference */
51 kobject_put(kobj: &mk->kobj);
52 }
53 }
54
55 if (!mk)
56 return 0;
57
58 ret = sysfs_create_link(kobj: &drv->p->kobj, target: &mk->kobj, name: "module");
59 if (ret)
60 return ret;
61
62 driver_name = make_driver_name(drv);
63 if (!driver_name) {
64 ret = -ENOMEM;
65 goto out_remove_kobj;
66 }
67
68 module_create_drivers_dir(mk);
69 if (!mk->drivers_dir) {
70 ret = -EINVAL;
71 goto out_free_driver_name;
72 }
73
74 ret = sysfs_create_link(kobj: mk->drivers_dir, target: &drv->p->kobj, name: driver_name);
75 if (ret)
76 goto out_remove_drivers_dir;
77
78 kfree(objp: driver_name);
79
80 return 0;
81
82out_remove_drivers_dir:
83 sysfs_remove_link(kobj: mk->drivers_dir, name: driver_name);
84
85out_free_driver_name:
86 kfree(objp: driver_name);
87
88out_remove_kobj:
89 sysfs_remove_link(kobj: &drv->p->kobj, name: "module");
90 return ret;
91}
92
93void 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 sysfs_remove_link(kobj: &drv->p->kobj, name: "module");
102
103 if (drv->owner)
104 mk = &drv->owner->mkobj;
105 else if (drv->p->mkobj)
106 mk = drv->p->mkobj;
107 if (mk && mk->drivers_dir) {
108 driver_name = make_driver_name(drv);
109 if (driver_name) {
110 sysfs_remove_link(kobj: mk->drivers_dir, name: driver_name);
111 kfree(objp: driver_name);
112 }
113 }
114}
115

source code of linux/drivers/base/module.c