1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Copyright (C) 2023 Google Corporation
4 */
5
6 #include <linux/devcoredump.h>
7
8 #include <asm/unaligned.h>
9 #include <net/bluetooth/bluetooth.h>
10 #include <net/bluetooth/hci_core.h>
11
12 enum hci_devcoredump_pkt_type {
13 HCI_DEVCOREDUMP_PKT_INIT,
14 HCI_DEVCOREDUMP_PKT_SKB,
15 HCI_DEVCOREDUMP_PKT_PATTERN,
16 HCI_DEVCOREDUMP_PKT_COMPLETE,
17 HCI_DEVCOREDUMP_PKT_ABORT,
18 };
19
20 struct hci_devcoredump_skb_cb {
21 u16 pkt_type;
22 };
23
24 struct hci_devcoredump_skb_pattern {
25 u8 pattern;
26 u32 len;
27 } __packed;
28
29 #define hci_dmp_cb(skb) ((struct hci_devcoredump_skb_cb *)((skb)->cb))
30
31 #define DBG_UNEXPECTED_STATE() \
32 bt_dev_dbg(hdev, \
33 "Unexpected packet (%d) for state (%d). ", \
34 hci_dmp_cb(skb)->pkt_type, hdev->dump.state)
35
36 #define MAX_DEVCOREDUMP_HDR_SIZE 512 /* bytes */
37
38 static int hci_devcd_update_hdr_state(char *buf, size_t size, int state)
39 {
40 int len = 0;
41
42 if (!buf)
43 return 0;
44
45 len = scnprintf(buf, size, "Bluetooth devcoredump\nState: %d\n", state);
46
47 return len + 1; /* scnprintf adds \0 at the end upon state rewrite */
48 }
49
50 /* Call with hci_dev_lock only. */
51 static int hci_devcd_update_state(struct hci_dev *hdev, int state)
52 {
53 bt_dev_dbg(hdev, "Updating devcoredump state from %d to %d.",
54 hdev->dump.state, state);
55
56 hdev->dump.state = state;
57
58 return hci_devcd_update_hdr_state(hdev->dump.head,
59 hdev->dump.alloc_size, state);
60 }
61
62 static int hci_devcd_mkheader(struct hci_dev *hdev, struct sk_buff *skb)
63 {
64 char dump_start[] = "--- Start dump ---\n";
65 char hdr[80];
66 int hdr_len;
67
68 hdr_len = hci_devcd_update_hdr_state(hdr, sizeof(hdr),
69 HCI_DEVCOREDUMP_IDLE);
70 skb_put_data(skb, hdr, hdr_len);
71
72 if (hdev->dump.dmp_hdr)
73 hdev->dump.dmp_hdr(hdev, skb);
74
75 skb_put_data(skb, dump_start, strlen(dump_start));
76
77 return skb->len;
78 }
79
80 /* Do not call with hci_dev_lock since this calls driver code. */
81 static void hci_devcd_notify(struct hci_dev *hdev, int state)
82 {
83 if (hdev->dump.notify_change)
84 hdev->dump.notify_change(hdev, state);
85 }
86
87 /* Call with hci_dev_lock only. */
88 void hci_devcd_reset(struct hci_dev *hdev)
89 {
90 hdev->dump.head = NULL;
91 hdev->dump.tail = NULL;
92 hdev->dump.alloc_size = 0;
93
94 hci_devcd_update_state(hdev, HCI_DEVCOREDUMP_IDLE);
95
96 cancel_delayed_work(&hdev->dump.dump_timeout);
97 skb_queue_purge(&hdev->dump.dump_q);
98 }
99
100 /* Call with hci_dev_lock only. */
101 static void hci_devcd_free(struct hci_dev *hdev)
102 {
103 vfree(hdev->dump.head);
104
105 hci_devcd_reset(hdev);
106 }
107
108 /* Call with hci_dev_lock only. */
109 static int hci_devcd_alloc(struct hci_dev *hdev, u32 size)
110 {
111 hdev->dump.head = vmalloc(size);
112 if (!hdev->dump.head)
113 return -ENOMEM;
114
115 hdev->dump.alloc_size = size;
116 hdev->dump.tail = hdev->dump.head;
117 hdev->dump.end = hdev->dump.head + size;
118
119 hci_devcd_update_state(hdev, HCI_DEVCOREDUMP_IDLE);
120
121 return 0;
122 }
123
124 /* Call with hci_dev_lock only. */
125 static bool hci_devcd_copy(struct hci_dev *hdev, char *buf, u32 size)
126 {
127 if (hdev->dump.tail + size > hdev->dump.end)
128 return false;
129
130 memcpy(hdev->dump.tail, buf, size);
131 hdev->dump.tail += size;
132
133 return true;
134 }
135
136 /* Call with hci_dev_lock only. */
137 static bool hci_devcd_memset(struct hci_dev *hdev, u8 pattern, u32 len)
138 {
139 if (hdev->dump.tail + len > hdev->dump.end)
140 return false;
141
142 memset(hdev->dump.tail, pattern, len);
143 hdev->dump.tail += len;
144
145 return true;
146 }
147
148 /* Call with hci_dev_lock only. */
149 static int hci_devcd_prepare(struct hci_dev *hdev, u32 dump_size)
150 {
151 struct sk_buff *skb;
152 int dump_hdr_size;
153 int err = 0;
154
155 skb = alloc_skb(MAX_DEVCOREDUMP_HDR_SIZE, GFP_ATOMIC);
156 if (!skb)
157 return -ENOMEM;
158
159 dump_hdr_size = hci_devcd_mkheader(hdev, skb);
160
161 if (hci_devcd_alloc(hdev, dump_hdr_size + dump_size)) {
162 err = -ENOMEM;
163 goto hdr_free;
164 }
165
166 /* Insert the device header */
167 if (!hci_devcd_copy(hdev, skb->data, skb->len)) {
168 bt_dev_err(hdev, "Failed to insert header");
169 hci_devcd_free(hdev);
170
171 err = -ENOMEM;
172 goto hdr_free;
173 }
174
175 hdr_free:
176 kfree_skb(skb);
177
178 return err;
179 }
180
181 static void hci_devcd_handle_pkt_init(struct hci_dev *hdev, struct sk_buff *skb)
182 {
183 u32 dump_size;
184
185 if (hdev->dump.state != HCI_DEVCOREDUMP_IDLE) {
186 DBG_UNEXPECTED_STATE();
187 return;
188 }
189
190 if (skb->len != sizeof(dump_size)) {
191 bt_dev_dbg(hdev, "Invalid dump init pkt");
192 return;
193 }
194
195 dump_size = get_unaligned_le32(skb_pull_data(skb, 4));
196 if (!dump_size) {
197 bt_dev_err(hdev, "Zero size dump init pkt");
198 return;
199 }
200
201 if (hci_devcd_prepare(hdev, dump_size)) {
202 bt_dev_err(hdev, "Failed to prepare for dump");
203 return;
204 }
205
206 hci_devcd_update_state(hdev, HCI_DEVCOREDUMP_ACTIVE);
207 queue_delayed_work(hdev->workqueue, &hdev->dump.dump_timeout,
208 hdev->dump.timeout);
209 }
210
211 static void hci_devcd_handle_pkt_skb(struct hci_dev *hdev, struct sk_buff *skb)
212 {
213 if (hdev->dump.state != HCI_DEVCOREDUMP_ACTIVE) {
214 DBG_UNEXPECTED_STATE();
215 return;
216 }
217
218 if (!hci_devcd_copy(hdev, skb->data, skb->len))
219 bt_dev_dbg(hdev, "Failed to insert skb");
220 }
221
222 static void hci_devcd_handle_pkt_pattern(struct hci_dev *hdev,
223 struct sk_buff *skb)
224 {
225 struct hci_devcoredump_skb_pattern *pattern;
226
227 if (hdev->dump.state != HCI_DEVCOREDUMP_ACTIVE) {
228 DBG_UNEXPECTED_STATE();
229 return;
230 }
231
232 if (skb->len != sizeof(*pattern)) {
233 bt_dev_dbg(hdev, "Invalid pattern skb");
234 return;
235 }
236
237 pattern = skb_pull_data(skb, sizeof(*pattern));
238
239 if (!hci_devcd_memset(hdev, pattern->pattern, pattern->len))
240 bt_dev_dbg(hdev, "Failed to set pattern");
241 }
242
243 static void hci_devcd_handle_pkt_complete(struct hci_dev *hdev,
244 struct sk_buff *skb)
245 {
246 u32 dump_size;
247
248 if (hdev->dump.state != HCI_DEVCOREDUMP_ACTIVE) {
249 DBG_UNEXPECTED_STATE();
250 return;
251 }
252
253 hci_devcd_update_state(hdev, HCI_DEVCOREDUMP_DONE);
254 dump_size = hdev->dump.tail - hdev->dump.head;
255
256 bt_dev_dbg(hdev, "complete with size %u (expect %zu)", dump_size,
257 hdev->dump.alloc_size);
258
259 dev_coredumpv(&hdev->dev, hdev->dump.head, dump_size, GFP_KERNEL);
260 }
261
262 static void hci_devcd_handle_pkt_abort(struct hci_dev *hdev,
263 struct sk_buff *skb)
264 {
265 u32 dump_size;
266
267 if (hdev->dump.state != HCI_DEVCOREDUMP_ACTIVE) {
268 DBG_UNEXPECTED_STATE();
269 return;
270 }
271
272 hci_devcd_update_state(hdev, HCI_DEVCOREDUMP_ABORT);
273 dump_size = hdev->dump.tail - hdev->dump.head;
274
275 bt_dev_dbg(hdev, "aborted with size %u (expect %zu)", dump_size,
276 hdev->dump.alloc_size);
277
278 /* Emit a devcoredump with the available data */
279 dev_coredumpv(&hdev->dev, hdev->dump.head, dump_size, GFP_KERNEL);
280 }
281
282 /* Bluetooth devcoredump state machine.
283 *
284 * Devcoredump states:
285 *
286 * HCI_DEVCOREDUMP_IDLE: The default state.
287 *
288 * HCI_DEVCOREDUMP_ACTIVE: A devcoredump will be in this state once it has
289 * been initialized using hci_devcd_init(). Once active, the driver
290 * can append data using hci_devcd_append() or insert a pattern
291 * using hci_devcd_append_pattern().
292 *
293 * HCI_DEVCOREDUMP_DONE: Once the dump collection is complete, the drive
294 * can signal the completion using hci_devcd_complete(). A
295 * devcoredump is generated indicating the completion event and
296 * then the state machine is reset to the default state.
297 *
298 * HCI_DEVCOREDUMP_ABORT: The driver can cancel ongoing dump collection in
299 * case of any error using hci_devcd_abort(). A devcoredump is
300 * still generated with the available data indicating the abort
301 * event and then the state machine is reset to the default state.
302 *
303 * HCI_DEVCOREDUMP_TIMEOUT: A timeout timer for HCI_DEVCOREDUMP_TIMEOUT sec
304 * is started during devcoredump initialization. Once the timeout
305 * occurs, the driver is notified, a devcoredump is generated with
306 * the available data indicating the timeout event and then the
307 * state machine is reset to the default state.
308 *
309 * The driver must register using hci_devcd_register() before using the hci
310 * devcoredump APIs.
311 */
312 void hci_devcd_rx(struct work_struct *work)
313 {
314 struct hci_dev *hdev = container_of(work, struct hci_dev, dump.dump_rx);
315 struct sk_buff *skb;
316 int start_state;
317
318 while ((skb = skb_dequeue(&hdev->dump.dump_q))) {
319 /* Return if timeout occurs. The timeout handler function
320 * hci_devcd_timeout() will report the available dump data.
321 */
322 if (hdev->dump.state == HCI_DEVCOREDUMP_TIMEOUT) {
323 kfree_skb(skb);
324 return;
325 }
326
327 hci_dev_lock(hdev);
328 start_state = hdev->dump.state;
329
330 switch (hci_dmp_cb(skb)->pkt_type) {
331 case HCI_DEVCOREDUMP_PKT_INIT:
332 hci_devcd_handle_pkt_init(hdev, skb);
333 break;
334
335 case HCI_DEVCOREDUMP_PKT_SKB:
336 hci_devcd_handle_pkt_skb(hdev, skb);
337 break;
338
339 case HCI_DEVCOREDUMP_PKT_PATTERN:
340 hci_devcd_handle_pkt_pattern(hdev, skb);
341 break;
342
343 case HCI_DEVCOREDUMP_PKT_COMPLETE:
344 hci_devcd_handle_pkt_complete(hdev, skb);
345 break;
346
347 case HCI_DEVCOREDUMP_PKT_ABORT:
348 hci_devcd_handle_pkt_abort(hdev, skb);
349 break;
350
351 default:
352 bt_dev_dbg(hdev, "Unknown packet (%d) for state (%d). ",
353 hci_dmp_cb(skb)->pkt_type, hdev->dump.state);
354 break;
355 }
356
357 hci_dev_unlock(hdev);
358 kfree_skb(skb);
359
360 /* Notify the driver about any state changes before resetting
361 * the state machine
362 */
363 if (start_state != hdev->dump.state)
364 hci_devcd_notify(hdev, hdev->dump.state);
365
366 /* Reset the state machine if the devcoredump is complete */
367 hci_dev_lock(hdev);
368 if (hdev->dump.state == HCI_DEVCOREDUMP_DONE ||
369 hdev->dump.state == HCI_DEVCOREDUMP_ABORT)
370 hci_devcd_reset(hdev);
371 hci_dev_unlock(hdev);
372 }
373 }
374 EXPORT_SYMBOL(hci_devcd_rx);
375
376 void hci_devcd_timeout(struct work_struct *work)
377 {
378 struct hci_dev *hdev = container_of(work, struct hci_dev,
379 dump.dump_timeout.work);
380 u32 dump_size;
381
382 hci_devcd_notify(hdev, HCI_DEVCOREDUMP_TIMEOUT);
383
384 hci_dev_lock(hdev);
385
386 cancel_work(&hdev->dump.dump_rx);
387
388 hci_devcd_update_state(hdev, HCI_DEVCOREDUMP_TIMEOUT);
389
390 dump_size = hdev->dump.tail - hdev->dump.head;
391 bt_dev_dbg(hdev, "timeout with size %u (expect %zu)", dump_size,
392 hdev->dump.alloc_size);
393
394 /* Emit a devcoredump with the available data */
395 dev_coredumpv(&hdev->dev, hdev->dump.head, dump_size, GFP_KERNEL);
396
397 hci_devcd_reset(hdev);
398
399 hci_dev_unlock(hdev);
400 }
401 EXPORT_SYMBOL(hci_devcd_timeout);
402
403 int hci_devcd_register(struct hci_dev *hdev, coredump_t coredump,
404 dmp_hdr_t dmp_hdr, notify_change_t notify_change)
405 {
406 /* Driver must implement coredump() and dmp_hdr() functions for
407 * bluetooth devcoredump. The coredump() should trigger a coredump
408 * event on the controller when the device's coredump sysfs entry is
409 * written to. The dmp_hdr() should create a dump header to identify
410 * the controller/fw/driver info.
411 */
412 if (!coredump || !dmp_hdr)
413 return -EINVAL;
414
415 hci_dev_lock(hdev);
416 hdev->dump.coredump = coredump;
417 hdev->dump.dmp_hdr = dmp_hdr;
418 hdev->dump.notify_change = notify_change;
419 hdev->dump.supported = true;
420 hdev->dump.timeout = DEVCOREDUMP_TIMEOUT;
421 hci_dev_unlock(hdev);
422
423 return 0;
424 }
425 EXPORT_SYMBOL(hci_devcd_register);
426
427 static inline bool hci_devcd_enabled(struct hci_dev *hdev)
428 {
429 return hdev->dump.supported;
430 }
431
432 int hci_devcd_init(struct hci_dev *hdev, u32 dump_size)
433 {
434 struct sk_buff *skb;
435
436 if (!hci_devcd_enabled(hdev))
437 return -EOPNOTSUPP;
438
439 skb = alloc_skb(sizeof(dump_size), GFP_ATOMIC);
440 if (!skb)
441 return -ENOMEM;
442
443 hci_dmp_cb(skb)->pkt_type = HCI_DEVCOREDUMP_PKT_INIT;
444 put_unaligned_le32(dump_size, skb_put(skb, 4));
445
446 skb_queue_tail(&hdev->dump.dump_q, skb);
447 queue_work(hdev->workqueue, &hdev->dump.dump_rx);
448
449 return 0;
450 }
451 EXPORT_SYMBOL(hci_devcd_init);
452
453 int hci_devcd_append(struct hci_dev *hdev, struct sk_buff *skb)
454 {
455 if (!skb)
456 return -ENOMEM;
457
458 if (!hci_devcd_enabled(hdev)) {
459 kfree_skb(skb);
460 return -EOPNOTSUPP;
461 }
462
463 hci_dmp_cb(skb)->pkt_type = HCI_DEVCOREDUMP_PKT_SKB;
464
465 skb_queue_tail(&hdev->dump.dump_q, skb);
466 queue_work(hdev->workqueue, &hdev->dump.dump_rx);
467
468 return 0;
469 }
470 EXPORT_SYMBOL(hci_devcd_append);
471
472 int hci_devcd_append_pattern(struct hci_dev *hdev, u8 pattern, u32 len)
473 {
474 struct hci_devcoredump_skb_pattern p;
475 struct sk_buff *skb;
476
477 if (!hci_devcd_enabled(hdev))
478 return -EOPNOTSUPP;
479
480 skb = alloc_skb(sizeof(p), GFP_ATOMIC);
481 if (!skb)
482 return -ENOMEM;
483
484 p.pattern = pattern;
485 p.len = len;
486
487 hci_dmp_cb(skb)->pkt_type = HCI_DEVCOREDUMP_PKT_PATTERN;
488 skb_put_data(skb, &p, sizeof(p));
489
490 skb_queue_tail(&hdev->dump.dump_q, skb);
491 queue_work(hdev->workqueue, &hdev->dump.dump_rx);
492
493 return 0;
494 }
495 EXPORT_SYMBOL(hci_devcd_append_pattern);
496
497 int hci_devcd_complete(struct hci_dev *hdev)
498 {
499 struct sk_buff *skb;
500
501 if (!hci_devcd_enabled(hdev))
502 return -EOPNOTSUPP;
503
504 skb = alloc_skb(0, GFP_ATOMIC);
505 if (!skb)
506 return -ENOMEM;
507
508 hci_dmp_cb(skb)->pkt_type = HCI_DEVCOREDUMP_PKT_COMPLETE;
509
510 skb_queue_tail(&hdev->dump.dump_q, skb);
511 queue_work(hdev->workqueue, &hdev->dump.dump_rx);
512
513 return 0;
514 }
515 EXPORT_SYMBOL(hci_devcd_complete);
516
517 int hci_devcd_abort(struct hci_dev *hdev)
518 {
519 struct sk_buff *skb;
520
521 if (!hci_devcd_enabled(hdev))
522 return -EOPNOTSUPP;
523
524 skb = alloc_skb(0, GFP_ATOMIC);
525 if (!skb)
526 return -ENOMEM;
527
528 hci_dmp_cb(skb)->pkt_type = HCI_DEVCOREDUMP_PKT_ABORT;
529
530 skb_queue_tail(&hdev->dump.dump_q, skb);
531 queue_work(hdev->workqueue, &hdev->dump.dump_rx);
532
533 return 0;
534 }
535 EXPORT_SYMBOL(hci_devcd_abort);
536
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