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(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(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
33void module_add_driver(struct module *mod, struct device_driver *drv)
34{
35 char *driver_name;
36 int no_warn;
37 struct module_kobject *mk = NULL;
38
39 if (!drv)
40 return;
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(kobj: mkobj);
55 }
56 }
57
58 if (!mk)
59 return;
60
61 /* Don't check return codes; these calls are idempotent */
62 no_warn = sysfs_create_link(kobj: &drv->p->kobj, target: &mk->kobj, name: "module");
63 driver_name = make_driver_name(drv);
64 if (driver_name) {
65 module_create_drivers_dir(mk);
66 no_warn = sysfs_create_link(kobj: mk->drivers_dir, target: &drv->p->kobj,
67 name: driver_name);
68 kfree(objp: driver_name);
69 }
70}
71
72void module_remove_driver(struct device_driver *drv)
73{
74 struct module_kobject *mk = NULL;
75 char *driver_name;
76
77 if (!drv)
78 return;
79
80 sysfs_remove_link(kobj: &drv->p->kobj, name: "module");
81
82 if (drv->owner)
83 mk = &drv->owner->mkobj;
84 else if (drv->p->mkobj)
85 mk = drv->p->mkobj;
86 if (mk && mk->drivers_dir) {
87 driver_name = make_driver_name(drv);
88 if (driver_name) {
89 sysfs_remove_link(kobj: mk->drivers_dir, name: driver_name);
90 kfree(objp: driver_name);
91 }
92 }
93}
94

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