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1// SPDX-License-Identifier: GPL-2.0
2/*
3 * The USB Monitor, inspired by Dave Harding's USBMon.
4 *
5 * mon_main.c: Main file, module initiation and exit, registrations, etc.
6 *
7 * Copyright (C) 2005 Pete Zaitcev (zaitcev@redhat.com)
8 */
9
10#include <linux/kernel.h>
11#include <linux/module.h>
12#include <linux/usb.h>
13#include <linux/usb/hcd.h>
14#include <linux/slab.h>
15#include <linux/notifier.h>
16#include <linux/mutex.h>
17
18#include "usb_mon.h"
19
20
21static void mon_stop(struct mon_bus *mbus);
22static void mon_dissolve(struct mon_bus *mbus, struct usb_bus *ubus);
23static void mon_bus_drop(struct kref *r);
24static void mon_bus_init(struct usb_bus *ubus);
25
26DEFINE_MUTEX(mon_lock);
27
28struct mon_bus mon_bus0; /* Pseudo bus meaning "all buses" */
29static LIST_HEAD(mon_buses); /* All buses we know: struct mon_bus */
30
31/*
32 * Link a reader into the bus.
33 *
34 * This must be called with mon_lock taken because of mbus->ref.
35 */
36void mon_reader_add(struct mon_bus *mbus, struct mon_reader *r)
37{
38 unsigned long flags;
39 struct list_head *p;
40
41 spin_lock_irqsave(&mbus->lock, flags);
42 if (mbus->nreaders == 0) {
43 if (mbus == &mon_bus0) {
44 list_for_each (p, &mon_buses) {
45 struct mon_bus *m1;
46 m1 = list_entry(p, struct mon_bus, bus_link);
47 m1->u_bus->monitored = 1;
48 }
49 } else {
50 mbus->u_bus->monitored = 1;
51 }
52 }
53 mbus->nreaders++;
54 list_add_tail(&r->r_link, &mbus->r_list);
55 spin_unlock_irqrestore(&mbus->lock, flags);
56
57 kref_get(&mbus->ref);
58}
59
60/*
61 * Unlink reader from the bus.
62 *
63 * This is called with mon_lock taken, so we can decrement mbus->ref.
64 */
65void mon_reader_del(struct mon_bus *mbus, struct mon_reader *r)
66{
67 unsigned long flags;
68
69 spin_lock_irqsave(&mbus->lock, flags);
70 list_del(&r->r_link);
71 --mbus->nreaders;
72 if (mbus->nreaders == 0)
73 mon_stop(mbus);
74 spin_unlock_irqrestore(&mbus->lock, flags);
75
76 kref_put(&mbus->ref, mon_bus_drop);
77}
78
79/*
80 */
81static void mon_bus_submit(struct mon_bus *mbus, struct urb *urb)
82{
83 unsigned long flags;
84 struct mon_reader *r;
85
86 spin_lock_irqsave(&mbus->lock, flags);
87 mbus->cnt_events++;
88 list_for_each_entry(r, &mbus->r_list, r_link)
89 r->rnf_submit(r->r_data, urb);
90 spin_unlock_irqrestore(&mbus->lock, flags);
91}
92
93static void mon_submit(struct usb_bus *ubus, struct urb *urb)
94{
95 struct mon_bus *mbus;
96
97 mbus = ubus->mon_bus;
98 if (mbus != NULL)
99 mon_bus_submit(mbus, urb);
100 mon_bus_submit(&mon_bus0, urb);
101}
102
103/*
104 */
105static void mon_bus_submit_error(struct mon_bus *mbus, struct urb *urb, int error)
106{
107 unsigned long flags;
108 struct mon_reader *r;
109
110 spin_lock_irqsave(&mbus->lock, flags);
111 mbus->cnt_events++;
112 list_for_each_entry(r, &mbus->r_list, r_link)
113 r->rnf_error(r->r_data, urb, error);
114 spin_unlock_irqrestore(&mbus->lock, flags);
115}
116
117static void mon_submit_error(struct usb_bus *ubus, struct urb *urb, int error)
118{
119 struct mon_bus *mbus;
120
121 mbus = ubus->mon_bus;
122 if (mbus != NULL)
123 mon_bus_submit_error(mbus, urb, error);
124 mon_bus_submit_error(&mon_bus0, urb, error);
125}
126
127/*
128 */
129static void mon_bus_complete(struct mon_bus *mbus, struct urb *urb, int status)
130{
131 unsigned long flags;
132 struct mon_reader *r;
133
134 spin_lock_irqsave(&mbus->lock, flags);
135 mbus->cnt_events++;
136 list_for_each_entry(r, &mbus->r_list, r_link)
137 r->rnf_complete(r->r_data, urb, status);
138 spin_unlock_irqrestore(&mbus->lock, flags);
139}
140
141static void mon_complete(struct usb_bus *ubus, struct urb *urb, int status)
142{
143 struct mon_bus *mbus;
144
145 mbus = ubus->mon_bus;
146 if (mbus != NULL)
147 mon_bus_complete(mbus, urb, status);
148 mon_bus_complete(&mon_bus0, urb, status);
149}
150
151/* int (*unlink_urb) (struct urb *urb, int status); */
152
153/*
154 * Stop monitoring.
155 */
156static void mon_stop(struct mon_bus *mbus)
157{
158 struct usb_bus *ubus;
159
160 if (mbus == &mon_bus0) {
161 list_for_each_entry(mbus, &mon_buses, bus_link) {
162 /*
163 * We do not change nreaders here, so rely on mon_lock.
164 */
165 if (mbus->nreaders == 0 && (ubus = mbus->u_bus) != NULL)
166 ubus->monitored = 0;
167 }
168 } else {
169 /*
170 * A stop can be called for a dissolved mon_bus in case of
171 * a reader staying across an rmmod foo_hcd, so test ->u_bus.
172 */
173 if (mon_bus0.nreaders == 0 && (ubus = mbus->u_bus) != NULL) {
174 ubus->monitored = 0;
175 mb();
176 }
177 }
178}
179
180/*
181 * Add a USB bus (usually by a modprobe foo-hcd)
182 *
183 * This does not return an error code because the core cannot care less
184 * if monitoring is not established.
185 */
186static void mon_bus_add(struct usb_bus *ubus)
187{
188 mon_bus_init(ubus);
189 mutex_lock(&mon_lock);
190 if (mon_bus0.nreaders != 0)
191 ubus->monitored = 1;
192 mutex_unlock(&mon_lock);
193}
194
195/*
196 * Remove a USB bus (either from rmmod foo-hcd or from a hot-remove event).
197 */
198static void mon_bus_remove(struct usb_bus *ubus)
199{
200 struct mon_bus *mbus = ubus->mon_bus;
201
202 mutex_lock(&mon_lock);
203 list_del(&mbus->bus_link);
204 if (mbus->text_inited)
205 mon_text_del(mbus);
206 if (mbus->bin_inited)
207 mon_bin_del(mbus);
208
209 mon_dissolve(mbus, ubus);
210 kref_put(&mbus->ref, mon_bus_drop);
211 mutex_unlock(&mon_lock);
212}
213
214static int mon_notify(struct notifier_block *self, unsigned long action,
215 void *dev)
216{
217 switch (action) {
218 case USB_BUS_ADD:
219 mon_bus_add(dev);
220 break;
221 case USB_BUS_REMOVE:
222 mon_bus_remove(dev);
223 }
224 return NOTIFY_OK;
225}
226
227static struct notifier_block mon_nb = {
228 .notifier_call = mon_notify,
229};
230
231/*
232 * Ops
233 */
234static const struct usb_mon_operations mon_ops_0 = {
235 .urb_submit = mon_submit,
236 .urb_submit_error = mon_submit_error,
237 .urb_complete = mon_complete,
238};
239
240/*
241 * Tear usb_bus and mon_bus apart.
242 */
243static void mon_dissolve(struct mon_bus *mbus, struct usb_bus *ubus)
244{
245
246 if (ubus->monitored) {
247 ubus->monitored = 0;
248 mb();
249 }
250
251 ubus->mon_bus = NULL;
252 mbus->u_bus = NULL;
253 mb();
254
255 /* We want synchronize_irq() here, but that needs an argument. */
256}
257
258/*
259 */
260static void mon_bus_drop(struct kref *r)
261{
262 struct mon_bus *mbus = container_of(r, struct mon_bus, ref);
263 kfree(mbus);
264}
265
266/*
267 * Initialize a bus for us:
268 * - allocate mon_bus
269 * - refcount USB bus struct
270 * - link
271 */
272static void mon_bus_init(struct usb_bus *ubus)
273{
274 struct mon_bus *mbus;
275
276 mbus = kzalloc(sizeof(struct mon_bus), GFP_KERNEL);
277 if (mbus == NULL)
278 goto err_alloc;
279 kref_init(&mbus->ref);
280 spin_lock_init(&mbus->lock);
281 INIT_LIST_HEAD(&mbus->r_list);
282
283 /*
284 * We don't need to take a reference to ubus, because we receive
285 * a notification if the bus is about to be removed.
286 */
287 mbus->u_bus = ubus;
288 ubus->mon_bus = mbus;
289
290 mbus->text_inited = mon_text_add(mbus, ubus);
291 mbus->bin_inited = mon_bin_add(mbus, ubus);
292
293 mutex_lock(&mon_lock);
294 list_add_tail(&mbus->bus_link, &mon_buses);
295 mutex_unlock(&mon_lock);
296 return;
297
298err_alloc:
299 return;
300}
301
302static void mon_bus0_init(void)
303{
304 struct mon_bus *mbus = &mon_bus0;
305
306 kref_init(&mbus->ref);
307 spin_lock_init(&mbus->lock);
308 INIT_LIST_HEAD(&mbus->r_list);
309
310 mbus->text_inited = mon_text_add(mbus, NULL);
311 mbus->bin_inited = mon_bin_add(mbus, NULL);
312}
313
314/*
315 * Search a USB bus by number. Notice that USB bus numbers start from one,
316 * which we may later use to identify "all" with zero.
317 *
318 * This function must be called with mon_lock held.
319 *
320 * This is obviously inefficient and may be revised in the future.
321 */
322struct mon_bus *mon_bus_lookup(unsigned int num)
323{
324 struct mon_bus *mbus;
325
326 if (num == 0) {
327 return &mon_bus0;
328 }
329 list_for_each_entry(mbus, &mon_buses, bus_link) {
330 if (mbus->u_bus->busnum == num) {
331 return mbus;
332 }
333 }
334 return NULL;
335}
336
337static int __init mon_init(void)
338{
339 struct usb_bus *ubus;
340 int rc, id;
341
342 if ((rc = mon_text_init()) != 0)
343 goto err_text;
344 if ((rc = mon_bin_init()) != 0)
345 goto err_bin;
346
347 mon_bus0_init();
348
349 if (usb_mon_register(&mon_ops_0) != 0) {
350 printk(KERN_NOTICE TAG ": unable to register with the core\n");
351 rc = -ENODEV;
352 goto err_reg;
353 }
354 // MOD_INC_USE_COUNT(which_module?);
355
356 mutex_lock(&usb_bus_idr_lock);
357 idr_for_each_entry(&usb_bus_idr, ubus, id)
358 mon_bus_init(ubus);
359 usb_register_notify(&mon_nb);
360 mutex_unlock(&usb_bus_idr_lock);
361 return 0;
362
363err_reg:
364 mon_bin_exit();
365err_bin:
366 mon_text_exit();
367err_text:
368 return rc;
369}
370
371static void __exit mon_exit(void)
372{
373 struct mon_bus *mbus;
374 struct list_head *p;
375
376 usb_unregister_notify(&mon_nb);
377 usb_mon_deregister();
378
379 mutex_lock(&mon_lock);
380
381 while (!list_empty(&mon_buses)) {
382 p = mon_buses.next;
383 mbus = list_entry(p, struct mon_bus, bus_link);
384 list_del(p);
385
386 if (mbus->text_inited)
387 mon_text_del(mbus);
388 if (mbus->bin_inited)
389 mon_bin_del(mbus);
390
391 /*
392 * This never happens, because the open/close paths in
393 * file level maintain module use counters and so rmmod fails
394 * before reaching here. However, better be safe...
395 */
396 if (mbus->nreaders) {
397 printk(KERN_ERR TAG
398 ": Outstanding opens (%d) on usb%d, leaking...\n",
399 mbus->nreaders, mbus->u_bus->busnum);
400 kref_get(&mbus->ref); /* Force leak */
401 }
402
403 mon_dissolve(mbus, mbus->u_bus);
404 kref_put(&mbus->ref, mon_bus_drop);
405 }
406
407 mbus = &mon_bus0;
408 if (mbus->text_inited)
409 mon_text_del(mbus);
410 if (mbus->bin_inited)
411 mon_bin_del(mbus);
412
413 mutex_unlock(&mon_lock);
414
415 mon_text_exit();
416 mon_bin_exit();
417}
418
419module_init(mon_init);
420module_exit(mon_exit);
421
422MODULE_LICENSE("GPL");
1/*
2 * The USB Monitor, inspired by Dave Harding's USBMon.
3 *
4 * mon_main.c: Main file, module initiation and exit, registrations, etc.
5 *
6 * Copyright (C) 2005 Pete Zaitcev (zaitcev@redhat.com)
7 */
8
9#include <linux/kernel.h>
10#include <linux/module.h>
11#include <linux/usb.h>
12#include <linux/usb/hcd.h>
13#include <linux/slab.h>
14#include <linux/notifier.h>
15#include <linux/mutex.h>
16
17#include "usb_mon.h"
18
19
20static void mon_stop(struct mon_bus *mbus);
21static void mon_dissolve(struct mon_bus *mbus, struct usb_bus *ubus);
22static void mon_bus_drop(struct kref *r);
23static void mon_bus_init(struct usb_bus *ubus);
24
25DEFINE_MUTEX(mon_lock);
26
27struct mon_bus mon_bus0; /* Pseudo bus meaning "all buses" */
28static LIST_HEAD(mon_buses); /* All buses we know: struct mon_bus */
29
30/*
31 * Link a reader into the bus.
32 *
33 * This must be called with mon_lock taken because of mbus->ref.
34 */
35void mon_reader_add(struct mon_bus *mbus, struct mon_reader *r)
36{
37 unsigned long flags;
38 struct list_head *p;
39
40 spin_lock_irqsave(&mbus->lock, flags);
41 if (mbus->nreaders == 0) {
42 if (mbus == &mon_bus0) {
43 list_for_each (p, &mon_buses) {
44 struct mon_bus *m1;
45 m1 = list_entry(p, struct mon_bus, bus_link);
46 m1->u_bus->monitored = 1;
47 }
48 } else {
49 mbus->u_bus->monitored = 1;
50 }
51 }
52 mbus->nreaders++;
53 list_add_tail(&r->r_link, &mbus->r_list);
54 spin_unlock_irqrestore(&mbus->lock, flags);
55
56 kref_get(&mbus->ref);
57}
58
59/*
60 * Unlink reader from the bus.
61 *
62 * This is called with mon_lock taken, so we can decrement mbus->ref.
63 */
64void mon_reader_del(struct mon_bus *mbus, struct mon_reader *r)
65{
66 unsigned long flags;
67
68 spin_lock_irqsave(&mbus->lock, flags);
69 list_del(&r->r_link);
70 --mbus->nreaders;
71 if (mbus->nreaders == 0)
72 mon_stop(mbus);
73 spin_unlock_irqrestore(&mbus->lock, flags);
74
75 kref_put(&mbus->ref, mon_bus_drop);
76}
77
78/*
79 */
80static void mon_bus_submit(struct mon_bus *mbus, struct urb *urb)
81{
82 unsigned long flags;
83 struct list_head *pos;
84 struct mon_reader *r;
85
86 spin_lock_irqsave(&mbus->lock, flags);
87 mbus->cnt_events++;
88 list_for_each (pos, &mbus->r_list) {
89 r = list_entry(pos, struct mon_reader, r_link);
90 r->rnf_submit(r->r_data, urb);
91 }
92 spin_unlock_irqrestore(&mbus->lock, flags);
93}
94
95static void mon_submit(struct usb_bus *ubus, struct urb *urb)
96{
97 struct mon_bus *mbus;
98
99 mbus = ubus->mon_bus;
100 if (mbus != NULL)
101 mon_bus_submit(mbus, urb);
102 mon_bus_submit(&mon_bus0, urb);
103}
104
105/*
106 */
107static void mon_bus_submit_error(struct mon_bus *mbus, struct urb *urb, int error)
108{
109 unsigned long flags;
110 struct list_head *pos;
111 struct mon_reader *r;
112
113 spin_lock_irqsave(&mbus->lock, flags);
114 mbus->cnt_events++;
115 list_for_each (pos, &mbus->r_list) {
116 r = list_entry(pos, struct mon_reader, r_link);
117 r->rnf_error(r->r_data, urb, error);
118 }
119 spin_unlock_irqrestore(&mbus->lock, flags);
120}
121
122static void mon_submit_error(struct usb_bus *ubus, struct urb *urb, int error)
123{
124 struct mon_bus *mbus;
125
126 mbus = ubus->mon_bus;
127 if (mbus != NULL)
128 mon_bus_submit_error(mbus, urb, error);
129 mon_bus_submit_error(&mon_bus0, urb, error);
130}
131
132/*
133 */
134static void mon_bus_complete(struct mon_bus *mbus, struct urb *urb, int status)
135{
136 unsigned long flags;
137 struct list_head *pos;
138 struct mon_reader *r;
139
140 spin_lock_irqsave(&mbus->lock, flags);
141 mbus->cnt_events++;
142 list_for_each (pos, &mbus->r_list) {
143 r = list_entry(pos, struct mon_reader, r_link);
144 r->rnf_complete(r->r_data, urb, status);
145 }
146 spin_unlock_irqrestore(&mbus->lock, flags);
147}
148
149static void mon_complete(struct usb_bus *ubus, struct urb *urb, int status)
150{
151 struct mon_bus *mbus;
152
153 mbus = ubus->mon_bus;
154 if (mbus != NULL)
155 mon_bus_complete(mbus, urb, status);
156 mon_bus_complete(&mon_bus0, urb, status);
157}
158
159/* int (*unlink_urb) (struct urb *urb, int status); */
160
161/*
162 * Stop monitoring.
163 */
164static void mon_stop(struct mon_bus *mbus)
165{
166 struct usb_bus *ubus;
167 struct list_head *p;
168
169 if (mbus == &mon_bus0) {
170 list_for_each (p, &mon_buses) {
171 mbus = list_entry(p, struct mon_bus, bus_link);
172 /*
173 * We do not change nreaders here, so rely on mon_lock.
174 */
175 if (mbus->nreaders == 0 && (ubus = mbus->u_bus) != NULL)
176 ubus->monitored = 0;
177 }
178 } else {
179 /*
180 * A stop can be called for a dissolved mon_bus in case of
181 * a reader staying across an rmmod foo_hcd, so test ->u_bus.
182 */
183 if (mon_bus0.nreaders == 0 && (ubus = mbus->u_bus) != NULL) {
184 ubus->monitored = 0;
185 mb();
186 }
187 }
188}
189
190/*
191 * Add a USB bus (usually by a modprobe foo-hcd)
192 *
193 * This does not return an error code because the core cannot care less
194 * if monitoring is not established.
195 */
196static void mon_bus_add(struct usb_bus *ubus)
197{
198 mon_bus_init(ubus);
199 mutex_lock(&mon_lock);
200 if (mon_bus0.nreaders != 0)
201 ubus->monitored = 1;
202 mutex_unlock(&mon_lock);
203}
204
205/*
206 * Remove a USB bus (either from rmmod foo-hcd or from a hot-remove event).
207 */
208static void mon_bus_remove(struct usb_bus *ubus)
209{
210 struct mon_bus *mbus = ubus->mon_bus;
211
212 mutex_lock(&mon_lock);
213 list_del(&mbus->bus_link);
214 if (mbus->text_inited)
215 mon_text_del(mbus);
216 if (mbus->bin_inited)
217 mon_bin_del(mbus);
218
219 mon_dissolve(mbus, ubus);
220 kref_put(&mbus->ref, mon_bus_drop);
221 mutex_unlock(&mon_lock);
222}
223
224static int mon_notify(struct notifier_block *self, unsigned long action,
225 void *dev)
226{
227 switch (action) {
228 case USB_BUS_ADD:
229 mon_bus_add(dev);
230 break;
231 case USB_BUS_REMOVE:
232 mon_bus_remove(dev);
233 }
234 return NOTIFY_OK;
235}
236
237static struct notifier_block mon_nb = {
238 .notifier_call = mon_notify,
239};
240
241/*
242 * Ops
243 */
244static const struct usb_mon_operations mon_ops_0 = {
245 .urb_submit = mon_submit,
246 .urb_submit_error = mon_submit_error,
247 .urb_complete = mon_complete,
248};
249
250/*
251 * Tear usb_bus and mon_bus apart.
252 */
253static void mon_dissolve(struct mon_bus *mbus, struct usb_bus *ubus)
254{
255
256 if (ubus->monitored) {
257 ubus->monitored = 0;
258 mb();
259 }
260
261 ubus->mon_bus = NULL;
262 mbus->u_bus = NULL;
263 mb();
264
265 /* We want synchronize_irq() here, but that needs an argument. */
266}
267
268/*
269 */
270static void mon_bus_drop(struct kref *r)
271{
272 struct mon_bus *mbus = container_of(r, struct mon_bus, ref);
273 kfree(mbus);
274}
275
276/*
277 * Initialize a bus for us:
278 * - allocate mon_bus
279 * - refcount USB bus struct
280 * - link
281 */
282static void mon_bus_init(struct usb_bus *ubus)
283{
284 struct mon_bus *mbus;
285
286 mbus = kzalloc(sizeof(struct mon_bus), GFP_KERNEL);
287 if (mbus == NULL)
288 goto err_alloc;
289 kref_init(&mbus->ref);
290 spin_lock_init(&mbus->lock);
291 INIT_LIST_HEAD(&mbus->r_list);
292
293 /*
294 * We don't need to take a reference to ubus, because we receive
295 * a notification if the bus is about to be removed.
296 */
297 mbus->u_bus = ubus;
298 ubus->mon_bus = mbus;
299
300 mbus->text_inited = mon_text_add(mbus, ubus);
301 mbus->bin_inited = mon_bin_add(mbus, ubus);
302
303 mutex_lock(&mon_lock);
304 list_add_tail(&mbus->bus_link, &mon_buses);
305 mutex_unlock(&mon_lock);
306 return;
307
308err_alloc:
309 return;
310}
311
312static void mon_bus0_init(void)
313{
314 struct mon_bus *mbus = &mon_bus0;
315
316 kref_init(&mbus->ref);
317 spin_lock_init(&mbus->lock);
318 INIT_LIST_HEAD(&mbus->r_list);
319
320 mbus->text_inited = mon_text_add(mbus, NULL);
321 mbus->bin_inited = mon_bin_add(mbus, NULL);
322}
323
324/*
325 * Search a USB bus by number. Notice that USB bus numbers start from one,
326 * which we may later use to identify "all" with zero.
327 *
328 * This function must be called with mon_lock held.
329 *
330 * This is obviously inefficient and may be revised in the future.
331 */
332struct mon_bus *mon_bus_lookup(unsigned int num)
333{
334 struct list_head *p;
335 struct mon_bus *mbus;
336
337 if (num == 0) {
338 return &mon_bus0;
339 }
340 list_for_each (p, &mon_buses) {
341 mbus = list_entry(p, struct mon_bus, bus_link);
342 if (mbus->u_bus->busnum == num) {
343 return mbus;
344 }
345 }
346 return NULL;
347}
348
349static int __init mon_init(void)
350{
351 struct usb_bus *ubus;
352 int rc, id;
353
354 if ((rc = mon_text_init()) != 0)
355 goto err_text;
356 if ((rc = mon_bin_init()) != 0)
357 goto err_bin;
358
359 mon_bus0_init();
360
361 if (usb_mon_register(&mon_ops_0) != 0) {
362 printk(KERN_NOTICE TAG ": unable to register with the core\n");
363 rc = -ENODEV;
364 goto err_reg;
365 }
366 // MOD_INC_USE_COUNT(which_module?);
367
368 mutex_lock(&usb_bus_idr_lock);
369 idr_for_each_entry(&usb_bus_idr, ubus, id)
370 mon_bus_init(ubus);
371 usb_register_notify(&mon_nb);
372 mutex_unlock(&usb_bus_idr_lock);
373 return 0;
374
375err_reg:
376 mon_bin_exit();
377err_bin:
378 mon_text_exit();
379err_text:
380 return rc;
381}
382
383static void __exit mon_exit(void)
384{
385 struct mon_bus *mbus;
386 struct list_head *p;
387
388 usb_unregister_notify(&mon_nb);
389 usb_mon_deregister();
390
391 mutex_lock(&mon_lock);
392
393 while (!list_empty(&mon_buses)) {
394 p = mon_buses.next;
395 mbus = list_entry(p, struct mon_bus, bus_link);
396 list_del(p);
397
398 if (mbus->text_inited)
399 mon_text_del(mbus);
400 if (mbus->bin_inited)
401 mon_bin_del(mbus);
402
403 /*
404 * This never happens, because the open/close paths in
405 * file level maintain module use counters and so rmmod fails
406 * before reaching here. However, better be safe...
407 */
408 if (mbus->nreaders) {
409 printk(KERN_ERR TAG
410 ": Outstanding opens (%d) on usb%d, leaking...\n",
411 mbus->nreaders, mbus->u_bus->busnum);
412 atomic_set(&mbus->ref.refcount, 2); /* Force leak */
413 }
414
415 mon_dissolve(mbus, mbus->u_bus);
416 kref_put(&mbus->ref, mon_bus_drop);
417 }
418
419 mbus = &mon_bus0;
420 if (mbus->text_inited)
421 mon_text_del(mbus);
422 if (mbus->bin_inited)
423 mon_bin_del(mbus);
424
425 mutex_unlock(&mon_lock);
426
427 mon_text_exit();
428 mon_bin_exit();
429}
430
431module_init(mon_init);
432module_exit(mon_exit);
433
434MODULE_LICENSE("GPL");