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d26c3321 WL |
1 | // SPDX-License-Identifier: GPL-2.0 |
2 | /* | |
3 | * Provide a pstore intermediate backend, organized into kernel memory | |
4 | * allocated zones that are then mapped and flushed into a single | |
5 | * contiguous region on a storage backend of some kind (block, mtd, etc). | |
6 | */ | |
7 | ||
8 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt | |
9 | ||
10 | #include <linux/kernel.h> | |
11 | #include <linux/module.h> | |
12 | #include <linux/slab.h> | |
13 | #include <linux/mount.h> | |
14 | #include <linux/printk.h> | |
15 | #include <linux/fs.h> | |
16 | #include <linux/pstore_zone.h> | |
17 | #include <linux/kdev_t.h> | |
18 | #include <linux/device.h> | |
19 | #include <linux/namei.h> | |
20 | #include <linux/fcntl.h> | |
21 | #include <linux/uio.h> | |
22 | #include <linux/writeback.h> | |
23 | #include "internal.h" | |
24 | ||
25 | /** | |
4fd15eaf | 26 | * struct psz_buffer - header of zone to flush to storage |
d26c3321 WL |
27 | * |
28 | * @sig: signature to indicate header (PSZ_SIG xor PSZONE-type value) | |
29 | * @datalen: length of data in @data | |
0dc06826 | 30 | * @start: offset into @data where the beginning of the stored bytes begin |
d26c3321 WL |
31 | * @data: zone data. |
32 | */ | |
33 | struct psz_buffer { | |
34 | #define PSZ_SIG (0x43474244) /* DBGC */ | |
35 | uint32_t sig; | |
36 | atomic_t datalen; | |
0dc06826 | 37 | atomic_t start; |
d26c3321 WL |
38 | uint8_t data[]; |
39 | }; | |
40 | ||
41 | /** | |
42 | * struct psz_kmsg_header - kmsg dump-specific header to flush to storage | |
43 | * | |
44 | * @magic: magic num for kmsg dump header | |
45 | * @time: kmsg dump trigger time | |
46 | * @compressed: whether conpressed | |
47 | * @counter: kmsg dump counter | |
48 | * @reason: the kmsg dump reason (e.g. oops, panic, etc) | |
49 | * @data: pointer to log data | |
50 | * | |
51 | * This is a sub-header for a kmsg dump, trailing after &psz_buffer. | |
52 | */ | |
53 | struct psz_kmsg_header { | |
54 | #define PSTORE_KMSG_HEADER_MAGIC 0x4dfc3ae5 /* Just a random number */ | |
55 | uint32_t magic; | |
56 | struct timespec64 time; | |
57 | bool compressed; | |
58 | uint32_t counter; | |
59 | enum kmsg_dump_reason reason; | |
60 | uint8_t data[]; | |
61 | }; | |
62 | ||
63 | /** | |
64 | * struct pstore_zone - single stored buffer | |
65 | * | |
66 | * @off: zone offset of storage | |
67 | * @type: front-end type for this zone | |
68 | * @name: front-end name for this zone | |
69 | * @buffer: pointer to data buffer managed by this zone | |
70 | * @oldbuf: pointer to old data buffer | |
71 | * @buffer_size: bytes in @buffer->data | |
72 | * @should_recover: whether this zone should recover from storage | |
73 | * @dirty: whether the data in @buffer dirty | |
74 | * | |
75 | * zone structure in memory. | |
76 | */ | |
77 | struct pstore_zone { | |
78 | loff_t off; | |
79 | const char *name; | |
80 | enum pstore_type_id type; | |
81 | ||
82 | struct psz_buffer *buffer; | |
83 | struct psz_buffer *oldbuf; | |
84 | size_t buffer_size; | |
85 | bool should_recover; | |
86 | atomic_t dirty; | |
87 | }; | |
88 | ||
89 | /** | |
90 | * struct psz_context - all about running state of pstore/zone | |
91 | * | |
92 | * @kpszs: kmsg dump storage zones | |
0dc06826 | 93 | * @ppsz: pmsg storage zone |
cc9c4d1b | 94 | * @cpsz: console storage zone |
34327e9f | 95 | * @fpszs: ftrace storage zones |
d26c3321 WL |
96 | * @kmsg_max_cnt: max count of @kpszs |
97 | * @kmsg_read_cnt: counter of total read kmsg dumps | |
98 | * @kmsg_write_cnt: counter of total kmsg dump writes | |
0dc06826 | 99 | * @pmsg_read_cnt: counter of total read pmsg zone |
cc9c4d1b | 100 | * @console_read_cnt: counter of total read console zone |
34327e9f WL |
101 | * @ftrace_max_cnt: max count of @fpszs |
102 | * @ftrace_read_cnt: counter of max read ftrace zone | |
d26c3321 WL |
103 | * @oops_counter: counter of oops dumps |
104 | * @panic_counter: counter of panic dumps | |
105 | * @recovered: whether finished recovering data from storage | |
106 | * @on_panic: whether panic is happening | |
107 | * @pstore_zone_info_lock: lock to @pstore_zone_info | |
108 | * @pstore_zone_info: information from backend | |
109 | * @pstore: structure for pstore | |
110 | */ | |
111 | struct psz_context { | |
112 | struct pstore_zone **kpszs; | |
0dc06826 | 113 | struct pstore_zone *ppsz; |
cc9c4d1b | 114 | struct pstore_zone *cpsz; |
34327e9f | 115 | struct pstore_zone **fpszs; |
d26c3321 WL |
116 | unsigned int kmsg_max_cnt; |
117 | unsigned int kmsg_read_cnt; | |
118 | unsigned int kmsg_write_cnt; | |
0dc06826 | 119 | unsigned int pmsg_read_cnt; |
cc9c4d1b | 120 | unsigned int console_read_cnt; |
34327e9f WL |
121 | unsigned int ftrace_max_cnt; |
122 | unsigned int ftrace_read_cnt; | |
d26c3321 WL |
123 | /* |
124 | * These counters should be calculated during recovery. | |
125 | * It records the oops/panic times after crashes rather than boots. | |
126 | */ | |
127 | unsigned int oops_counter; | |
128 | unsigned int panic_counter; | |
129 | atomic_t recovered; | |
130 | atomic_t on_panic; | |
131 | ||
132 | /* | |
133 | * pstore_zone_info_lock protects this entire structure during calls | |
134 | * to register_pstore_zone()/unregister_pstore_zone(). | |
135 | */ | |
136 | struct mutex pstore_zone_info_lock; | |
137 | struct pstore_zone_info *pstore_zone_info; | |
138 | struct pstore_info pstore; | |
139 | }; | |
140 | static struct psz_context pstore_zone_cxt; | |
141 | ||
cc9c4d1b WL |
142 | static void psz_flush_all_dirty_zones(struct work_struct *); |
143 | static DECLARE_DELAYED_WORK(psz_cleaner, psz_flush_all_dirty_zones); | |
144 | ||
d26c3321 WL |
145 | /** |
146 | * enum psz_flush_mode - flush mode for psz_zone_write() | |
147 | * | |
148 | * @FLUSH_NONE: do not flush to storage but update data on memory | |
149 | * @FLUSH_PART: just flush part of data including meta data to storage | |
150 | * @FLUSH_META: just flush meta data of zone to storage | |
151 | * @FLUSH_ALL: flush all of zone | |
152 | */ | |
153 | enum psz_flush_mode { | |
154 | FLUSH_NONE = 0, | |
155 | FLUSH_PART, | |
156 | FLUSH_META, | |
157 | FLUSH_ALL, | |
158 | }; | |
159 | ||
160 | static inline int buffer_datalen(struct pstore_zone *zone) | |
161 | { | |
162 | return atomic_read(&zone->buffer->datalen); | |
163 | } | |
164 | ||
0dc06826 WL |
165 | static inline int buffer_start(struct pstore_zone *zone) |
166 | { | |
167 | return atomic_read(&zone->buffer->start); | |
168 | } | |
169 | ||
d26c3321 WL |
170 | static inline bool is_on_panic(void) |
171 | { | |
172 | return atomic_read(&pstore_zone_cxt.on_panic); | |
173 | } | |
174 | ||
0dc06826 | 175 | static ssize_t psz_zone_read_buffer(struct pstore_zone *zone, char *buf, |
d26c3321 WL |
176 | size_t len, unsigned long off) |
177 | { | |
0dc06826 | 178 | if (!buf || !zone || !zone->buffer) |
d26c3321 WL |
179 | return -EINVAL; |
180 | if (off > zone->buffer_size) | |
181 | return -EINVAL; | |
182 | len = min_t(size_t, len, zone->buffer_size - off); | |
183 | memcpy(buf, zone->buffer->data + off, len); | |
184 | return len; | |
185 | } | |
186 | ||
0dc06826 WL |
187 | static int psz_zone_read_oldbuf(struct pstore_zone *zone, char *buf, |
188 | size_t len, unsigned long off) | |
189 | { | |
190 | if (!buf || !zone || !zone->oldbuf) | |
191 | return -EINVAL; | |
192 | if (off > zone->buffer_size) | |
193 | return -EINVAL; | |
194 | len = min_t(size_t, len, zone->buffer_size - off); | |
195 | memcpy(buf, zone->oldbuf->data + off, len); | |
196 | return 0; | |
197 | } | |
198 | ||
d26c3321 WL |
199 | static int psz_zone_write(struct pstore_zone *zone, |
200 | enum psz_flush_mode flush_mode, const char *buf, | |
201 | size_t len, unsigned long off) | |
202 | { | |
203 | struct pstore_zone_info *info = pstore_zone_cxt.pstore_zone_info; | |
204 | ssize_t wcnt = 0; | |
205 | ssize_t (*writeop)(const char *buf, size_t bytes, loff_t pos); | |
206 | size_t wlen; | |
207 | ||
208 | if (off > zone->buffer_size) | |
209 | return -EINVAL; | |
210 | ||
211 | wlen = min_t(size_t, len, zone->buffer_size - off); | |
212 | if (buf && wlen) { | |
213 | memcpy(zone->buffer->data + off, buf, wlen); | |
214 | atomic_set(&zone->buffer->datalen, wlen + off); | |
215 | } | |
216 | ||
217 | /* avoid to damage old records */ | |
218 | if (!is_on_panic() && !atomic_read(&pstore_zone_cxt.recovered)) | |
219 | goto dirty; | |
220 | ||
221 | writeop = is_on_panic() ? info->panic_write : info->write; | |
222 | if (!writeop) | |
223 | goto dirty; | |
224 | ||
225 | switch (flush_mode) { | |
226 | case FLUSH_NONE: | |
227 | if (unlikely(buf && wlen)) | |
228 | goto dirty; | |
229 | return 0; | |
230 | case FLUSH_PART: | |
231 | wcnt = writeop((const char *)zone->buffer->data + off, wlen, | |
232 | zone->off + sizeof(*zone->buffer) + off); | |
233 | if (wcnt != wlen) | |
234 | goto dirty; | |
235 | fallthrough; | |
236 | case FLUSH_META: | |
237 | wlen = sizeof(struct psz_buffer); | |
238 | wcnt = writeop((const char *)zone->buffer, wlen, zone->off); | |
239 | if (wcnt != wlen) | |
240 | goto dirty; | |
241 | break; | |
242 | case FLUSH_ALL: | |
243 | wlen = zone->buffer_size + sizeof(*zone->buffer); | |
244 | wcnt = writeop((const char *)zone->buffer, wlen, zone->off); | |
245 | if (wcnt != wlen) | |
246 | goto dirty; | |
247 | break; | |
248 | } | |
249 | ||
250 | return 0; | |
251 | dirty: | |
335426c6 WL |
252 | /* no need to mark dirty if going to try next zone */ |
253 | if (wcnt == -ENOMSG) | |
254 | return -ENOMSG; | |
d26c3321 | 255 | atomic_set(&zone->dirty, true); |
cc9c4d1b WL |
256 | /* flush dirty zones nicely */ |
257 | if (wcnt == -EBUSY && !is_on_panic()) | |
258 | schedule_delayed_work(&psz_cleaner, msecs_to_jiffies(500)); | |
d26c3321 WL |
259 | return -EBUSY; |
260 | } | |
261 | ||
262 | static int psz_flush_dirty_zone(struct pstore_zone *zone) | |
263 | { | |
264 | int ret; | |
265 | ||
266 | if (unlikely(!zone)) | |
267 | return -EINVAL; | |
268 | ||
269 | if (unlikely(!atomic_read(&pstore_zone_cxt.recovered))) | |
270 | return -EBUSY; | |
271 | ||
272 | if (!atomic_xchg(&zone->dirty, false)) | |
273 | return 0; | |
274 | ||
275 | ret = psz_zone_write(zone, FLUSH_ALL, NULL, 0, 0); | |
276 | if (ret) | |
277 | atomic_set(&zone->dirty, true); | |
278 | return ret; | |
279 | } | |
280 | ||
281 | static int psz_flush_dirty_zones(struct pstore_zone **zones, unsigned int cnt) | |
282 | { | |
283 | int i, ret; | |
284 | struct pstore_zone *zone; | |
285 | ||
286 | if (!zones) | |
287 | return -EINVAL; | |
288 | ||
289 | for (i = 0; i < cnt; i++) { | |
290 | zone = zones[i]; | |
291 | if (!zone) | |
292 | return -EINVAL; | |
293 | ret = psz_flush_dirty_zone(zone); | |
294 | if (ret) | |
295 | return ret; | |
296 | } | |
297 | return 0; | |
298 | } | |
299 | ||
300 | static int psz_move_zone(struct pstore_zone *old, struct pstore_zone *new) | |
301 | { | |
302 | const char *data = (const char *)old->buffer->data; | |
303 | int ret; | |
304 | ||
305 | ret = psz_zone_write(new, FLUSH_ALL, data, buffer_datalen(old), 0); | |
306 | if (ret) { | |
307 | atomic_set(&new->buffer->datalen, 0); | |
308 | atomic_set(&new->dirty, false); | |
309 | return ret; | |
310 | } | |
311 | atomic_set(&old->buffer->datalen, 0); | |
312 | return 0; | |
313 | } | |
314 | ||
cc9c4d1b WL |
315 | static void psz_flush_all_dirty_zones(struct work_struct *work) |
316 | { | |
317 | struct psz_context *cxt = &pstore_zone_cxt; | |
318 | int ret = 0; | |
319 | ||
320 | if (cxt->ppsz) | |
321 | ret |= psz_flush_dirty_zone(cxt->ppsz); | |
322 | if (cxt->cpsz) | |
323 | ret |= psz_flush_dirty_zone(cxt->cpsz); | |
324 | if (cxt->kpszs) | |
325 | ret |= psz_flush_dirty_zones(cxt->kpszs, cxt->kmsg_max_cnt); | |
34327e9f WL |
326 | if (cxt->fpszs) |
327 | ret |= psz_flush_dirty_zones(cxt->fpszs, cxt->ftrace_max_cnt); | |
cc9c4d1b WL |
328 | if (ret && cxt->pstore_zone_info) |
329 | schedule_delayed_work(&psz_cleaner, msecs_to_jiffies(1000)); | |
330 | } | |
331 | ||
d26c3321 WL |
332 | static int psz_kmsg_recover_data(struct psz_context *cxt) |
333 | { | |
334 | struct pstore_zone_info *info = cxt->pstore_zone_info; | |
335 | struct pstore_zone *zone = NULL; | |
336 | struct psz_buffer *buf; | |
337 | unsigned long i; | |
338 | ssize_t rcnt; | |
339 | ||
340 | if (!info->read) | |
341 | return -EINVAL; | |
342 | ||
343 | for (i = 0; i < cxt->kmsg_max_cnt; i++) { | |
344 | zone = cxt->kpszs[i]; | |
345 | if (unlikely(!zone)) | |
346 | return -EINVAL; | |
347 | if (atomic_read(&zone->dirty)) { | |
348 | unsigned int wcnt = cxt->kmsg_write_cnt; | |
349 | struct pstore_zone *new = cxt->kpszs[wcnt]; | |
350 | int ret; | |
351 | ||
352 | ret = psz_move_zone(zone, new); | |
353 | if (ret) { | |
354 | pr_err("move zone from %lu to %d failed\n", | |
355 | i, wcnt); | |
356 | return ret; | |
357 | } | |
358 | cxt->kmsg_write_cnt = (wcnt + 1) % cxt->kmsg_max_cnt; | |
359 | } | |
360 | if (!zone->should_recover) | |
361 | continue; | |
362 | buf = zone->buffer; | |
363 | rcnt = info->read((char *)buf, zone->buffer_size + sizeof(*buf), | |
364 | zone->off); | |
365 | if (rcnt != zone->buffer_size + sizeof(*buf)) | |
2c09d144 | 366 | return rcnt < 0 ? rcnt : -EIO; |
d26c3321 WL |
367 | } |
368 | return 0; | |
369 | } | |
370 | ||
371 | static int psz_kmsg_recover_meta(struct psz_context *cxt) | |
372 | { | |
373 | struct pstore_zone_info *info = cxt->pstore_zone_info; | |
374 | struct pstore_zone *zone; | |
2c09d144 | 375 | ssize_t rcnt, len; |
d26c3321 WL |
376 | struct psz_buffer *buf; |
377 | struct psz_kmsg_header *hdr; | |
378 | struct timespec64 time = { }; | |
379 | unsigned long i; | |
380 | /* | |
381 | * Recover may on panic, we can't allocate any memory by kmalloc. | |
382 | * So, we use local array instead. | |
383 | */ | |
384 | char buffer_header[sizeof(*buf) + sizeof(*hdr)] = {0}; | |
385 | ||
386 | if (!info->read) | |
387 | return -EINVAL; | |
388 | ||
389 | len = sizeof(*buf) + sizeof(*hdr); | |
390 | buf = (struct psz_buffer *)buffer_header; | |
391 | for (i = 0; i < cxt->kmsg_max_cnt; i++) { | |
392 | zone = cxt->kpszs[i]; | |
393 | if (unlikely(!zone)) | |
394 | return -EINVAL; | |
395 | ||
396 | rcnt = info->read((char *)buf, len, zone->off); | |
335426c6 WL |
397 | if (rcnt == -ENOMSG) { |
398 | pr_debug("%s with id %lu may be broken, skip\n", | |
399 | zone->name, i); | |
400 | continue; | |
401 | } else if (rcnt != len) { | |
d26c3321 | 402 | pr_err("read %s with id %lu failed\n", zone->name, i); |
2c09d144 | 403 | return rcnt < 0 ? rcnt : -EIO; |
d26c3321 WL |
404 | } |
405 | ||
406 | if (buf->sig != zone->buffer->sig) { | |
407 | pr_debug("no valid data in kmsg dump zone %lu\n", i); | |
408 | continue; | |
409 | } | |
410 | ||
411 | if (zone->buffer_size < atomic_read(&buf->datalen)) { | |
412 | pr_info("found overtop zone: %s: id %lu, off %lld, size %zu\n", | |
413 | zone->name, i, zone->off, | |
414 | zone->buffer_size); | |
415 | continue; | |
416 | } | |
417 | ||
418 | hdr = (struct psz_kmsg_header *)buf->data; | |
419 | if (hdr->magic != PSTORE_KMSG_HEADER_MAGIC) { | |
420 | pr_info("found invalid zone: %s: id %lu, off %lld, size %zu\n", | |
421 | zone->name, i, zone->off, | |
422 | zone->buffer_size); | |
423 | continue; | |
424 | } | |
425 | ||
426 | /* | |
427 | * we get the newest zone, and the next one must be the oldest | |
428 | * or unused zone, because we do write one by one like a circle. | |
429 | */ | |
430 | if (hdr->time.tv_sec >= time.tv_sec) { | |
431 | time.tv_sec = hdr->time.tv_sec; | |
432 | cxt->kmsg_write_cnt = (i + 1) % cxt->kmsg_max_cnt; | |
433 | } | |
434 | ||
435 | if (hdr->reason == KMSG_DUMP_OOPS) | |
436 | cxt->oops_counter = | |
437 | max(cxt->oops_counter, hdr->counter); | |
438 | else if (hdr->reason == KMSG_DUMP_PANIC) | |
439 | cxt->panic_counter = | |
440 | max(cxt->panic_counter, hdr->counter); | |
441 | ||
442 | if (!atomic_read(&buf->datalen)) { | |
443 | pr_debug("found erased zone: %s: id %lu, off %lld, size %zu, datalen %d\n", | |
444 | zone->name, i, zone->off, | |
445 | zone->buffer_size, | |
446 | atomic_read(&buf->datalen)); | |
447 | continue; | |
448 | } | |
449 | ||
450 | if (!is_on_panic()) | |
451 | zone->should_recover = true; | |
452 | pr_debug("found nice zone: %s: id %lu, off %lld, size %zu, datalen %d\n", | |
453 | zone->name, i, zone->off, | |
454 | zone->buffer_size, atomic_read(&buf->datalen)); | |
455 | } | |
456 | ||
457 | return 0; | |
458 | } | |
459 | ||
460 | static int psz_kmsg_recover(struct psz_context *cxt) | |
461 | { | |
462 | int ret; | |
463 | ||
464 | if (!cxt->kpszs) | |
465 | return 0; | |
466 | ||
467 | ret = psz_kmsg_recover_meta(cxt); | |
468 | if (ret) | |
469 | goto recover_fail; | |
470 | ||
471 | ret = psz_kmsg_recover_data(cxt); | |
472 | if (ret) | |
473 | goto recover_fail; | |
474 | ||
475 | return 0; | |
476 | recover_fail: | |
477 | pr_debug("psz_recover_kmsg failed\n"); | |
478 | return ret; | |
479 | } | |
480 | ||
0dc06826 WL |
481 | static int psz_recover_zone(struct psz_context *cxt, struct pstore_zone *zone) |
482 | { | |
483 | struct pstore_zone_info *info = cxt->pstore_zone_info; | |
484 | struct psz_buffer *oldbuf, tmpbuf; | |
485 | int ret = 0; | |
486 | char *buf; | |
487 | ssize_t rcnt, len, start, off; | |
488 | ||
489 | if (!zone || zone->oldbuf) | |
490 | return 0; | |
491 | ||
492 | if (is_on_panic()) { | |
493 | /* save data as much as possible */ | |
494 | psz_flush_dirty_zone(zone); | |
495 | return 0; | |
496 | } | |
497 | ||
498 | if (unlikely(!info->read)) | |
499 | return -EINVAL; | |
500 | ||
501 | len = sizeof(struct psz_buffer); | |
502 | rcnt = info->read((char *)&tmpbuf, len, zone->off); | |
503 | if (rcnt != len) { | |
504 | pr_debug("read zone %s failed\n", zone->name); | |
2c09d144 | 505 | return rcnt < 0 ? rcnt : -EIO; |
0dc06826 WL |
506 | } |
507 | ||
508 | if (tmpbuf.sig != zone->buffer->sig) { | |
509 | pr_debug("no valid data in zone %s\n", zone->name); | |
510 | return 0; | |
511 | } | |
512 | ||
513 | if (zone->buffer_size < atomic_read(&tmpbuf.datalen) || | |
514 | zone->buffer_size < atomic_read(&tmpbuf.start)) { | |
515 | pr_info("found overtop zone: %s: off %lld, size %zu\n", | |
516 | zone->name, zone->off, zone->buffer_size); | |
517 | /* just keep going */ | |
518 | return 0; | |
519 | } | |
520 | ||
521 | if (!atomic_read(&tmpbuf.datalen)) { | |
522 | pr_debug("found erased zone: %s: off %lld, size %zu, datalen %d\n", | |
523 | zone->name, zone->off, zone->buffer_size, | |
524 | atomic_read(&tmpbuf.datalen)); | |
525 | return 0; | |
526 | } | |
527 | ||
528 | pr_debug("found nice zone: %s: off %lld, size %zu, datalen %d\n", | |
529 | zone->name, zone->off, zone->buffer_size, | |
530 | atomic_read(&tmpbuf.datalen)); | |
531 | ||
532 | len = atomic_read(&tmpbuf.datalen) + sizeof(*oldbuf); | |
533 | oldbuf = kzalloc(len, GFP_KERNEL); | |
534 | if (!oldbuf) | |
535 | return -ENOMEM; | |
536 | ||
537 | memcpy(oldbuf, &tmpbuf, sizeof(*oldbuf)); | |
538 | buf = (char *)oldbuf + sizeof(*oldbuf); | |
539 | len = atomic_read(&oldbuf->datalen); | |
540 | start = atomic_read(&oldbuf->start); | |
541 | off = zone->off + sizeof(*oldbuf); | |
542 | ||
543 | /* get part of data */ | |
544 | rcnt = info->read(buf, len - start, off + start); | |
545 | if (rcnt != len - start) { | |
546 | pr_err("read zone %s failed\n", zone->name); | |
2c09d144 | 547 | ret = rcnt < 0 ? rcnt : -EIO; |
0dc06826 WL |
548 | goto free_oldbuf; |
549 | } | |
550 | ||
551 | /* get the rest of data */ | |
552 | rcnt = info->read(buf + len - start, start, off); | |
553 | if (rcnt != start) { | |
554 | pr_err("read zone %s failed\n", zone->name); | |
2c09d144 | 555 | ret = rcnt < 0 ? rcnt : -EIO; |
0dc06826 WL |
556 | goto free_oldbuf; |
557 | } | |
558 | ||
559 | zone->oldbuf = oldbuf; | |
560 | psz_flush_dirty_zone(zone); | |
561 | return 0; | |
562 | ||
563 | free_oldbuf: | |
564 | kfree(oldbuf); | |
565 | return ret; | |
566 | } | |
567 | ||
34327e9f WL |
568 | static int psz_recover_zones(struct psz_context *cxt, |
569 | struct pstore_zone **zones, unsigned int cnt) | |
570 | { | |
571 | int ret; | |
572 | unsigned int i; | |
573 | struct pstore_zone *zone; | |
574 | ||
575 | if (!zones) | |
576 | return 0; | |
577 | ||
578 | for (i = 0; i < cnt; i++) { | |
579 | zone = zones[i]; | |
580 | if (unlikely(!zone)) | |
581 | continue; | |
582 | ret = psz_recover_zone(cxt, zone); | |
583 | if (ret) | |
584 | goto recover_fail; | |
585 | } | |
586 | ||
587 | return 0; | |
588 | recover_fail: | |
589 | pr_debug("recover %s[%u] failed\n", zone->name, i); | |
590 | return ret; | |
591 | } | |
592 | ||
d26c3321 WL |
593 | /** |
594 | * psz_recovery() - recover data from storage | |
595 | * @cxt: the context of pstore/zone | |
596 | * | |
597 | * recovery means reading data back from storage after rebooting | |
598 | * | |
599 | * Return: 0 on success, others on failure. | |
600 | */ | |
601 | static inline int psz_recovery(struct psz_context *cxt) | |
602 | { | |
603 | int ret; | |
604 | ||
605 | if (atomic_read(&cxt->recovered)) | |
606 | return 0; | |
607 | ||
608 | ret = psz_kmsg_recover(cxt); | |
0dc06826 WL |
609 | if (ret) |
610 | goto out; | |
d26c3321 | 611 | |
0dc06826 | 612 | ret = psz_recover_zone(cxt, cxt->ppsz); |
cc9c4d1b WL |
613 | if (ret) |
614 | goto out; | |
615 | ||
616 | ret = psz_recover_zone(cxt, cxt->cpsz); | |
34327e9f WL |
617 | if (ret) |
618 | goto out; | |
619 | ||
620 | ret = psz_recover_zones(cxt, cxt->fpszs, cxt->ftrace_max_cnt); | |
0dc06826 WL |
621 | |
622 | out: | |
d26c3321 WL |
623 | if (unlikely(ret)) |
624 | pr_err("recover failed\n"); | |
625 | else { | |
626 | pr_debug("recover end!\n"); | |
627 | atomic_set(&cxt->recovered, 1); | |
628 | } | |
629 | return ret; | |
630 | } | |
631 | ||
632 | static int psz_pstore_open(struct pstore_info *psi) | |
633 | { | |
634 | struct psz_context *cxt = psi->data; | |
635 | ||
636 | cxt->kmsg_read_cnt = 0; | |
0dc06826 | 637 | cxt->pmsg_read_cnt = 0; |
cc9c4d1b | 638 | cxt->console_read_cnt = 0; |
34327e9f | 639 | cxt->ftrace_read_cnt = 0; |
d26c3321 WL |
640 | return 0; |
641 | } | |
642 | ||
0dc06826 WL |
643 | static inline bool psz_old_ok(struct pstore_zone *zone) |
644 | { | |
645 | if (zone && zone->oldbuf && atomic_read(&zone->oldbuf->datalen)) | |
646 | return true; | |
647 | return false; | |
648 | } | |
649 | ||
d26c3321 WL |
650 | static inline bool psz_ok(struct pstore_zone *zone) |
651 | { | |
652 | if (zone && zone->buffer && buffer_datalen(zone)) | |
653 | return true; | |
654 | return false; | |
655 | } | |
656 | ||
657 | static inline int psz_kmsg_erase(struct psz_context *cxt, | |
658 | struct pstore_zone *zone, struct pstore_record *record) | |
659 | { | |
660 | struct psz_buffer *buffer = zone->buffer; | |
661 | struct psz_kmsg_header *hdr = | |
662 | (struct psz_kmsg_header *)buffer->data; | |
7dcb7848 | 663 | size_t size; |
d26c3321 WL |
664 | |
665 | if (unlikely(!psz_ok(zone))) | |
666 | return 0; | |
7dcb7848 | 667 | |
d26c3321 WL |
668 | /* this zone is already updated, no need to erase */ |
669 | if (record->count != hdr->counter) | |
670 | return 0; | |
671 | ||
7dcb7848 | 672 | size = buffer_datalen(zone) + sizeof(*zone->buffer); |
d26c3321 | 673 | atomic_set(&zone->buffer->datalen, 0); |
7dcb7848 WL |
674 | if (cxt->pstore_zone_info->erase) |
675 | return cxt->pstore_zone_info->erase(size, zone->off); | |
676 | else | |
677 | return psz_zone_write(zone, FLUSH_META, NULL, 0, 0); | |
d26c3321 WL |
678 | } |
679 | ||
0dc06826 WL |
680 | static inline int psz_record_erase(struct psz_context *cxt, |
681 | struct pstore_zone *zone) | |
682 | { | |
683 | if (unlikely(!psz_old_ok(zone))) | |
684 | return 0; | |
685 | ||
686 | kfree(zone->oldbuf); | |
687 | zone->oldbuf = NULL; | |
688 | /* | |
689 | * if there are new data in zone buffer, that means the old data | |
690 | * are already invalid. It is no need to flush 0 (erase) to | |
691 | * block device. | |
692 | */ | |
693 | if (!buffer_datalen(zone)) | |
694 | return psz_zone_write(zone, FLUSH_META, NULL, 0, 0); | |
695 | psz_flush_dirty_zone(zone); | |
696 | return 0; | |
697 | } | |
698 | ||
d26c3321 WL |
699 | static int psz_pstore_erase(struct pstore_record *record) |
700 | { | |
701 | struct psz_context *cxt = record->psi->data; | |
702 | ||
703 | switch (record->type) { | |
704 | case PSTORE_TYPE_DMESG: | |
705 | if (record->id >= cxt->kmsg_max_cnt) | |
706 | return -EINVAL; | |
707 | return psz_kmsg_erase(cxt, cxt->kpszs[record->id], record); | |
0dc06826 WL |
708 | case PSTORE_TYPE_PMSG: |
709 | return psz_record_erase(cxt, cxt->ppsz); | |
cc9c4d1b WL |
710 | case PSTORE_TYPE_CONSOLE: |
711 | return psz_record_erase(cxt, cxt->cpsz); | |
34327e9f WL |
712 | case PSTORE_TYPE_FTRACE: |
713 | if (record->id >= cxt->ftrace_max_cnt) | |
714 | return -EINVAL; | |
715 | return psz_record_erase(cxt, cxt->fpszs[record->id]); | |
cc9c4d1b | 716 | default: return -EINVAL; |
d26c3321 WL |
717 | } |
718 | } | |
719 | ||
720 | static void psz_write_kmsg_hdr(struct pstore_zone *zone, | |
721 | struct pstore_record *record) | |
722 | { | |
723 | struct psz_context *cxt = record->psi->data; | |
724 | struct psz_buffer *buffer = zone->buffer; | |
725 | struct psz_kmsg_header *hdr = | |
726 | (struct psz_kmsg_header *)buffer->data; | |
727 | ||
728 | hdr->magic = PSTORE_KMSG_HEADER_MAGIC; | |
729 | hdr->compressed = record->compressed; | |
730 | hdr->time.tv_sec = record->time.tv_sec; | |
731 | hdr->time.tv_nsec = record->time.tv_nsec; | |
732 | hdr->reason = record->reason; | |
733 | if (hdr->reason == KMSG_DUMP_OOPS) | |
734 | hdr->counter = ++cxt->oops_counter; | |
735 | else if (hdr->reason == KMSG_DUMP_PANIC) | |
736 | hdr->counter = ++cxt->panic_counter; | |
737 | else | |
738 | hdr->counter = 0; | |
739 | } | |
740 | ||
335426c6 WL |
741 | /* |
742 | * In case zone is broken, which may occur to MTD device, we try each zones, | |
743 | * start at cxt->kmsg_write_cnt. | |
744 | */ | |
d26c3321 WL |
745 | static inline int notrace psz_kmsg_write_record(struct psz_context *cxt, |
746 | struct pstore_record *record) | |
747 | { | |
748 | size_t size, hlen; | |
749 | struct pstore_zone *zone; | |
335426c6 | 750 | unsigned int i; |
d26c3321 | 751 | |
335426c6 WL |
752 | for (i = 0; i < cxt->kmsg_max_cnt; i++) { |
753 | unsigned int zonenum, len; | |
754 | int ret; | |
d26c3321 | 755 | |
335426c6 WL |
756 | zonenum = (cxt->kmsg_write_cnt + i) % cxt->kmsg_max_cnt; |
757 | zone = cxt->kpszs[zonenum]; | |
758 | if (unlikely(!zone)) | |
759 | return -ENOSPC; | |
760 | ||
761 | /* avoid destroying old data, allocate a new one */ | |
762 | len = zone->buffer_size + sizeof(*zone->buffer); | |
763 | zone->oldbuf = zone->buffer; | |
764 | zone->buffer = kzalloc(len, GFP_KERNEL); | |
765 | if (!zone->buffer) { | |
766 | zone->buffer = zone->oldbuf; | |
767 | return -ENOMEM; | |
768 | } | |
769 | zone->buffer->sig = zone->oldbuf->sig; | |
770 | ||
771 | pr_debug("write %s to zone id %d\n", zone->name, zonenum); | |
772 | psz_write_kmsg_hdr(zone, record); | |
773 | hlen = sizeof(struct psz_kmsg_header); | |
774 | size = min_t(size_t, record->size, zone->buffer_size - hlen); | |
775 | ret = psz_zone_write(zone, FLUSH_ALL, record->buf, size, hlen); | |
776 | if (likely(!ret || ret != -ENOMSG)) { | |
777 | cxt->kmsg_write_cnt = zonenum + 1; | |
778 | cxt->kmsg_write_cnt %= cxt->kmsg_max_cnt; | |
779 | /* no need to try next zone, free last zone buffer */ | |
780 | kfree(zone->oldbuf); | |
781 | zone->oldbuf = NULL; | |
782 | return ret; | |
783 | } | |
784 | ||
785 | pr_debug("zone %u may be broken, try next dmesg zone\n", | |
786 | zonenum); | |
787 | kfree(zone->buffer); | |
788 | zone->buffer = zone->oldbuf; | |
789 | zone->oldbuf = NULL; | |
790 | } | |
791 | ||
792 | return -EBUSY; | |
d26c3321 WL |
793 | } |
794 | ||
795 | static int notrace psz_kmsg_write(struct psz_context *cxt, | |
796 | struct pstore_record *record) | |
797 | { | |
798 | int ret; | |
799 | ||
800 | /* | |
801 | * Explicitly only take the first part of any new crash. | |
802 | * If our buffer is larger than kmsg_bytes, this can never happen, | |
803 | * and if our buffer is smaller than kmsg_bytes, we don't want the | |
804 | * report split across multiple records. | |
805 | */ | |
806 | if (record->part != 1) | |
807 | return -ENOSPC; | |
808 | ||
809 | if (!cxt->kpszs) | |
810 | return -ENOSPC; | |
811 | ||
812 | ret = psz_kmsg_write_record(cxt, record); | |
cc9c4d1b WL |
813 | if (!ret && is_on_panic()) { |
814 | /* ensure all data are flushed to storage when panic */ | |
d26c3321 | 815 | pr_debug("try to flush other dirty zones\n"); |
cc9c4d1b | 816 | psz_flush_all_dirty_zones(NULL); |
d26c3321 WL |
817 | } |
818 | ||
819 | /* always return 0 as we had handled it on buffer */ | |
820 | return 0; | |
821 | } | |
822 | ||
0dc06826 WL |
823 | static int notrace psz_record_write(struct pstore_zone *zone, |
824 | struct pstore_record *record) | |
825 | { | |
826 | size_t start, rem; | |
827 | bool is_full_data = false; | |
828 | char *buf; | |
829 | int cnt; | |
830 | ||
831 | if (!zone || !record) | |
832 | return -ENOSPC; | |
833 | ||
834 | if (atomic_read(&zone->buffer->datalen) >= zone->buffer_size) | |
835 | is_full_data = true; | |
836 | ||
837 | cnt = record->size; | |
838 | buf = record->buf; | |
839 | if (unlikely(cnt > zone->buffer_size)) { | |
840 | buf += cnt - zone->buffer_size; | |
841 | cnt = zone->buffer_size; | |
842 | } | |
843 | ||
844 | start = buffer_start(zone); | |
845 | rem = zone->buffer_size - start; | |
846 | if (unlikely(rem < cnt)) { | |
847 | psz_zone_write(zone, FLUSH_PART, buf, rem, start); | |
848 | buf += rem; | |
849 | cnt -= rem; | |
850 | start = 0; | |
851 | is_full_data = true; | |
852 | } | |
853 | ||
854 | atomic_set(&zone->buffer->start, cnt + start); | |
855 | psz_zone_write(zone, FLUSH_PART, buf, cnt, start); | |
856 | ||
857 | /** | |
858 | * psz_zone_write will set datalen as start + cnt. | |
859 | * It work if actual data length lesser than buffer size. | |
860 | * If data length greater than buffer size, pmsg will rewrite to | |
861 | * beginning of zone, which make buffer->datalen wrongly. | |
862 | * So we should reset datalen as buffer size once actual data length | |
863 | * greater than buffer size. | |
864 | */ | |
865 | if (is_full_data) { | |
866 | atomic_set(&zone->buffer->datalen, zone->buffer_size); | |
867 | psz_zone_write(zone, FLUSH_META, NULL, 0, 0); | |
868 | } | |
869 | return 0; | |
870 | } | |
871 | ||
d26c3321 WL |
872 | static int notrace psz_pstore_write(struct pstore_record *record) |
873 | { | |
874 | struct psz_context *cxt = record->psi->data; | |
875 | ||
876 | if (record->type == PSTORE_TYPE_DMESG && | |
877 | record->reason == KMSG_DUMP_PANIC) | |
878 | atomic_set(&cxt->on_panic, 1); | |
879 | ||
cc9c4d1b WL |
880 | /* |
881 | * if on panic, do not write except panic records | |
882 | * Fix case that panic_write prints log which wakes up console backend. | |
883 | */ | |
884 | if (is_on_panic() && record->type != PSTORE_TYPE_DMESG) | |
885 | return -EBUSY; | |
886 | ||
d26c3321 WL |
887 | switch (record->type) { |
888 | case PSTORE_TYPE_DMESG: | |
889 | return psz_kmsg_write(cxt, record); | |
cc9c4d1b WL |
890 | case PSTORE_TYPE_CONSOLE: |
891 | return psz_record_write(cxt->cpsz, record); | |
0dc06826 WL |
892 | case PSTORE_TYPE_PMSG: |
893 | return psz_record_write(cxt->ppsz, record); | |
34327e9f WL |
894 | case PSTORE_TYPE_FTRACE: { |
895 | int zonenum = smp_processor_id(); | |
896 | ||
897 | if (!cxt->fpszs) | |
898 | return -ENOSPC; | |
899 | return psz_record_write(cxt->fpszs[zonenum], record); | |
900 | } | |
d26c3321 WL |
901 | default: |
902 | return -EINVAL; | |
903 | } | |
904 | } | |
905 | ||
906 | static struct pstore_zone *psz_read_next_zone(struct psz_context *cxt) | |
907 | { | |
908 | struct pstore_zone *zone = NULL; | |
909 | ||
910 | while (cxt->kmsg_read_cnt < cxt->kmsg_max_cnt) { | |
911 | zone = cxt->kpszs[cxt->kmsg_read_cnt++]; | |
912 | if (psz_ok(zone)) | |
913 | return zone; | |
914 | } | |
915 | ||
34327e9f WL |
916 | if (cxt->ftrace_read_cnt < cxt->ftrace_max_cnt) |
917 | /* | |
918 | * No need psz_old_ok(). Let psz_ftrace_read() do so for | |
919 | * combination. psz_ftrace_read() should traverse over | |
920 | * all zones in case of some zone without data. | |
921 | */ | |
922 | return cxt->fpszs[cxt->ftrace_read_cnt++]; | |
923 | ||
0dc06826 WL |
924 | if (cxt->pmsg_read_cnt == 0) { |
925 | cxt->pmsg_read_cnt++; | |
926 | zone = cxt->ppsz; | |
927 | if (psz_old_ok(zone)) | |
928 | return zone; | |
929 | } | |
930 | ||
cc9c4d1b WL |
931 | if (cxt->console_read_cnt == 0) { |
932 | cxt->console_read_cnt++; | |
933 | zone = cxt->cpsz; | |
934 | if (psz_old_ok(zone)) | |
935 | return zone; | |
936 | } | |
937 | ||
d26c3321 WL |
938 | return NULL; |
939 | } | |
940 | ||
941 | static int psz_kmsg_read_hdr(struct pstore_zone *zone, | |
942 | struct pstore_record *record) | |
943 | { | |
944 | struct psz_buffer *buffer = zone->buffer; | |
945 | struct psz_kmsg_header *hdr = | |
946 | (struct psz_kmsg_header *)buffer->data; | |
947 | ||
948 | if (hdr->magic != PSTORE_KMSG_HEADER_MAGIC) | |
949 | return -EINVAL; | |
950 | record->compressed = hdr->compressed; | |
951 | record->time.tv_sec = hdr->time.tv_sec; | |
952 | record->time.tv_nsec = hdr->time.tv_nsec; | |
953 | record->reason = hdr->reason; | |
954 | record->count = hdr->counter; | |
955 | return 0; | |
956 | } | |
957 | ||
958 | static ssize_t psz_kmsg_read(struct pstore_zone *zone, | |
959 | struct pstore_record *record) | |
960 | { | |
961 | ssize_t size, hlen = 0; | |
962 | ||
963 | size = buffer_datalen(zone); | |
964 | /* Clear and skip this kmsg dump record if it has no valid header */ | |
965 | if (psz_kmsg_read_hdr(zone, record)) { | |
966 | atomic_set(&zone->buffer->datalen, 0); | |
967 | atomic_set(&zone->dirty, 0); | |
968 | return -ENOMSG; | |
969 | } | |
970 | size -= sizeof(struct psz_kmsg_header); | |
971 | ||
972 | if (!record->compressed) { | |
973 | char *buf = kasprintf(GFP_KERNEL, "%s: Total %d times\n", | |
974 | kmsg_dump_reason_str(record->reason), | |
975 | record->count); | |
976 | hlen = strlen(buf); | |
977 | record->buf = krealloc(buf, hlen + size, GFP_KERNEL); | |
978 | if (!record->buf) { | |
979 | kfree(buf); | |
980 | return -ENOMEM; | |
981 | } | |
982 | } else { | |
983 | record->buf = kmalloc(size, GFP_KERNEL); | |
984 | if (!record->buf) | |
985 | return -ENOMEM; | |
986 | } | |
987 | ||
0dc06826 | 988 | size = psz_zone_read_buffer(zone, record->buf + hlen, size, |
d26c3321 WL |
989 | sizeof(struct psz_kmsg_header)); |
990 | if (unlikely(size < 0)) { | |
991 | kfree(record->buf); | |
992 | return -ENOMSG; | |
993 | } | |
994 | ||
995 | return size + hlen; | |
996 | } | |
997 | ||
34327e9f WL |
998 | /* try to combine all ftrace zones */ |
999 | static ssize_t psz_ftrace_read(struct pstore_zone *zone, | |
1000 | struct pstore_record *record) | |
1001 | { | |
1002 | struct psz_context *cxt; | |
1003 | struct psz_buffer *buf; | |
1004 | int ret; | |
1005 | ||
1006 | if (!zone || !record) | |
1007 | return -ENOSPC; | |
1008 | ||
1009 | if (!psz_old_ok(zone)) | |
1010 | goto out; | |
1011 | ||
1012 | buf = (struct psz_buffer *)zone->oldbuf; | |
1013 | if (!buf) | |
1014 | return -ENOMSG; | |
1015 | ||
1016 | ret = pstore_ftrace_combine_log(&record->buf, &record->size, | |
1017 | (char *)buf->data, atomic_read(&buf->datalen)); | |
1018 | if (unlikely(ret)) | |
1019 | return ret; | |
1020 | ||
1021 | out: | |
1022 | cxt = record->psi->data; | |
1023 | if (cxt->ftrace_read_cnt < cxt->ftrace_max_cnt) | |
1024 | /* then, read next ftrace zone */ | |
1025 | return -ENOMSG; | |
1026 | record->id = 0; | |
1027 | return record->size ? record->size : -ENOMSG; | |
1028 | } | |
1029 | ||
0dc06826 WL |
1030 | static ssize_t psz_record_read(struct pstore_zone *zone, |
1031 | struct pstore_record *record) | |
1032 | { | |
1033 | size_t len; | |
1034 | struct psz_buffer *buf; | |
1035 | ||
1036 | if (!zone || !record) | |
1037 | return -ENOSPC; | |
1038 | ||
1039 | buf = (struct psz_buffer *)zone->oldbuf; | |
1040 | if (!buf) | |
1041 | return -ENOMSG; | |
1042 | ||
1043 | len = atomic_read(&buf->datalen); | |
1044 | record->buf = kmalloc(len, GFP_KERNEL); | |
1045 | if (!record->buf) | |
1046 | return -ENOMEM; | |
1047 | ||
1048 | if (unlikely(psz_zone_read_oldbuf(zone, record->buf, len, 0))) { | |
1049 | kfree(record->buf); | |
1050 | return -ENOMSG; | |
1051 | } | |
1052 | ||
1053 | return len; | |
1054 | } | |
1055 | ||
d26c3321 WL |
1056 | static ssize_t psz_pstore_read(struct pstore_record *record) |
1057 | { | |
1058 | struct psz_context *cxt = record->psi->data; | |
1059 | ssize_t (*readop)(struct pstore_zone *zone, | |
1060 | struct pstore_record *record); | |
1061 | struct pstore_zone *zone; | |
1062 | ssize_t ret; | |
1063 | ||
1064 | /* before read, we must recover from storage */ | |
1065 | ret = psz_recovery(cxt); | |
1066 | if (ret) | |
1067 | return ret; | |
1068 | ||
1069 | next_zone: | |
1070 | zone = psz_read_next_zone(cxt); | |
1071 | if (!zone) | |
1072 | return 0; | |
1073 | ||
1074 | record->type = zone->type; | |
1075 | switch (record->type) { | |
1076 | case PSTORE_TYPE_DMESG: | |
1077 | readop = psz_kmsg_read; | |
1078 | record->id = cxt->kmsg_read_cnt - 1; | |
1079 | break; | |
34327e9f WL |
1080 | case PSTORE_TYPE_FTRACE: |
1081 | readop = psz_ftrace_read; | |
1082 | break; | |
cc9c4d1b | 1083 | case PSTORE_TYPE_CONSOLE: |
0dc06826 WL |
1084 | case PSTORE_TYPE_PMSG: |
1085 | readop = psz_record_read; | |
1086 | break; | |
d26c3321 WL |
1087 | default: |
1088 | goto next_zone; | |
1089 | } | |
1090 | ||
1091 | ret = readop(zone, record); | |
1092 | if (ret == -ENOMSG) | |
1093 | goto next_zone; | |
1094 | return ret; | |
1095 | } | |
1096 | ||
1097 | static struct psz_context pstore_zone_cxt = { | |
1098 | .pstore_zone_info_lock = | |
1099 | __MUTEX_INITIALIZER(pstore_zone_cxt.pstore_zone_info_lock), | |
1100 | .recovered = ATOMIC_INIT(0), | |
1101 | .on_panic = ATOMIC_INIT(0), | |
1102 | .pstore = { | |
1103 | .owner = THIS_MODULE, | |
1104 | .open = psz_pstore_open, | |
1105 | .read = psz_pstore_read, | |
1106 | .write = psz_pstore_write, | |
1107 | .erase = psz_pstore_erase, | |
1108 | }, | |
1109 | }; | |
1110 | ||
1111 | static void psz_free_zone(struct pstore_zone **pszone) | |
1112 | { | |
1113 | struct pstore_zone *zone = *pszone; | |
1114 | ||
1115 | if (!zone) | |
1116 | return; | |
1117 | ||
1118 | kfree(zone->buffer); | |
1119 | kfree(zone); | |
1120 | *pszone = NULL; | |
1121 | } | |
1122 | ||
1123 | static void psz_free_zones(struct pstore_zone ***pszones, unsigned int *cnt) | |
1124 | { | |
1125 | struct pstore_zone **zones = *pszones; | |
1126 | ||
1127 | if (!zones) | |
1128 | return; | |
1129 | ||
1130 | while (*cnt > 0) { | |
1131 | (*cnt)--; | |
1132 | psz_free_zone(&(zones[*cnt])); | |
1133 | } | |
1134 | kfree(zones); | |
1135 | *pszones = NULL; | |
1136 | } | |
1137 | ||
1138 | static void psz_free_all_zones(struct psz_context *cxt) | |
1139 | { | |
1140 | if (cxt->kpszs) | |
1141 | psz_free_zones(&cxt->kpszs, &cxt->kmsg_max_cnt); | |
0dc06826 WL |
1142 | if (cxt->ppsz) |
1143 | psz_free_zone(&cxt->ppsz); | |
cc9c4d1b WL |
1144 | if (cxt->cpsz) |
1145 | psz_free_zone(&cxt->cpsz); | |
34327e9f WL |
1146 | if (cxt->fpszs) |
1147 | psz_free_zones(&cxt->fpszs, &cxt->ftrace_max_cnt); | |
d26c3321 WL |
1148 | } |
1149 | ||
1150 | static struct pstore_zone *psz_init_zone(enum pstore_type_id type, | |
1151 | loff_t *off, size_t size) | |
1152 | { | |
1153 | struct pstore_zone_info *info = pstore_zone_cxt.pstore_zone_info; | |
1154 | struct pstore_zone *zone; | |
1155 | const char *name = pstore_type_to_name(type); | |
1156 | ||
1157 | if (!size) | |
1158 | return NULL; | |
1159 | ||
1160 | if (*off + size > info->total_size) { | |
1161 | pr_err("no room for %s (0x%zx@0x%llx over 0x%lx)\n", | |
1162 | name, size, *off, info->total_size); | |
1163 | return ERR_PTR(-ENOMEM); | |
1164 | } | |
1165 | ||
1166 | zone = kzalloc(sizeof(struct pstore_zone), GFP_KERNEL); | |
1167 | if (!zone) | |
1168 | return ERR_PTR(-ENOMEM); | |
1169 | ||
1170 | zone->buffer = kmalloc(size, GFP_KERNEL); | |
1171 | if (!zone->buffer) { | |
1172 | kfree(zone); | |
1173 | return ERR_PTR(-ENOMEM); | |
1174 | } | |
1175 | memset(zone->buffer, 0xFF, size); | |
1176 | zone->off = *off; | |
1177 | zone->name = name; | |
1178 | zone->type = type; | |
1179 | zone->buffer_size = size - sizeof(struct psz_buffer); | |
1180 | zone->buffer->sig = type ^ PSZ_SIG; | |
0dc06826 | 1181 | zone->oldbuf = NULL; |
d26c3321 WL |
1182 | atomic_set(&zone->dirty, 0); |
1183 | atomic_set(&zone->buffer->datalen, 0); | |
0dc06826 | 1184 | atomic_set(&zone->buffer->start, 0); |
d26c3321 WL |
1185 | |
1186 | *off += size; | |
1187 | ||
1188 | pr_debug("pszone %s: off 0x%llx, %zu header, %zu data\n", zone->name, | |
1189 | zone->off, sizeof(*zone->buffer), zone->buffer_size); | |
1190 | return zone; | |
1191 | } | |
1192 | ||
1193 | static struct pstore_zone **psz_init_zones(enum pstore_type_id type, | |
1194 | loff_t *off, size_t total_size, ssize_t record_size, | |
1195 | unsigned int *cnt) | |
1196 | { | |
1197 | struct pstore_zone_info *info = pstore_zone_cxt.pstore_zone_info; | |
1198 | struct pstore_zone **zones, *zone; | |
1199 | const char *name = pstore_type_to_name(type); | |
1200 | int c, i; | |
1201 | ||
1202 | *cnt = 0; | |
1203 | if (!total_size || !record_size) | |
1204 | return NULL; | |
1205 | ||
1206 | if (*off + total_size > info->total_size) { | |
1207 | pr_err("no room for zones %s (0x%zx@0x%llx over 0x%lx)\n", | |
1208 | name, total_size, *off, info->total_size); | |
1209 | return ERR_PTR(-ENOMEM); | |
1210 | } | |
1211 | ||
1212 | c = total_size / record_size; | |
1213 | zones = kcalloc(c, sizeof(*zones), GFP_KERNEL); | |
1214 | if (!zones) { | |
1215 | pr_err("allocate for zones %s failed\n", name); | |
1216 | return ERR_PTR(-ENOMEM); | |
1217 | } | |
1218 | memset(zones, 0, c * sizeof(*zones)); | |
1219 | ||
1220 | for (i = 0; i < c; i++) { | |
1221 | zone = psz_init_zone(type, off, record_size); | |
1222 | if (!zone || IS_ERR(zone)) { | |
1223 | pr_err("initialize zones %s failed\n", name); | |
1224 | psz_free_zones(&zones, &i); | |
1225 | return (void *)zone; | |
1226 | } | |
1227 | zones[i] = zone; | |
1228 | } | |
1229 | ||
1230 | *cnt = c; | |
1231 | return zones; | |
1232 | } | |
1233 | ||
1234 | static int psz_alloc_zones(struct psz_context *cxt) | |
1235 | { | |
1236 | struct pstore_zone_info *info = cxt->pstore_zone_info; | |
1237 | loff_t off = 0; | |
1238 | int err; | |
0dc06826 WL |
1239 | size_t off_size = 0; |
1240 | ||
1241 | off_size += info->pmsg_size; | |
1242 | cxt->ppsz = psz_init_zone(PSTORE_TYPE_PMSG, &off, info->pmsg_size); | |
1243 | if (IS_ERR(cxt->ppsz)) { | |
1244 | err = PTR_ERR(cxt->ppsz); | |
1245 | cxt->ppsz = NULL; | |
1246 | goto free_out; | |
1247 | } | |
d26c3321 | 1248 | |
cc9c4d1b WL |
1249 | off_size += info->console_size; |
1250 | cxt->cpsz = psz_init_zone(PSTORE_TYPE_CONSOLE, &off, | |
1251 | info->console_size); | |
1252 | if (IS_ERR(cxt->cpsz)) { | |
1253 | err = PTR_ERR(cxt->cpsz); | |
1254 | cxt->cpsz = NULL; | |
1255 | goto free_out; | |
1256 | } | |
1257 | ||
34327e9f WL |
1258 | off_size += info->ftrace_size; |
1259 | cxt->fpszs = psz_init_zones(PSTORE_TYPE_FTRACE, &off, | |
1260 | info->ftrace_size, | |
1261 | info->ftrace_size / nr_cpu_ids, | |
1262 | &cxt->ftrace_max_cnt); | |
1263 | if (IS_ERR(cxt->fpszs)) { | |
1264 | err = PTR_ERR(cxt->fpszs); | |
1265 | cxt->fpszs = NULL; | |
1266 | goto free_out; | |
1267 | } | |
1268 | ||
0dc06826 WL |
1269 | cxt->kpszs = psz_init_zones(PSTORE_TYPE_DMESG, &off, |
1270 | info->total_size - off_size, | |
d26c3321 WL |
1271 | info->kmsg_size, &cxt->kmsg_max_cnt); |
1272 | if (IS_ERR(cxt->kpszs)) { | |
1273 | err = PTR_ERR(cxt->kpszs); | |
1274 | cxt->kpszs = NULL; | |
0dc06826 | 1275 | goto free_out; |
d26c3321 WL |
1276 | } |
1277 | ||
1278 | return 0; | |
0dc06826 WL |
1279 | free_out: |
1280 | psz_free_all_zones(cxt); | |
d26c3321 WL |
1281 | return err; |
1282 | } | |
1283 | ||
1284 | /** | |
1285 | * register_pstore_zone() - register to pstore/zone | |
1286 | * | |
1287 | * @info: back-end driver information. See &struct pstore_zone_info. | |
1288 | * | |
1289 | * Only one back-end at one time. | |
1290 | * | |
1291 | * Return: 0 on success, others on failure. | |
1292 | */ | |
1293 | int register_pstore_zone(struct pstore_zone_info *info) | |
1294 | { | |
1295 | int err = -EINVAL; | |
1296 | struct psz_context *cxt = &pstore_zone_cxt; | |
1297 | ||
1298 | if (info->total_size < 4096) { | |
1299 | pr_warn("total_size must be >= 4096\n"); | |
1300 | return -EINVAL; | |
1301 | } | |
cbf82e35 CH |
1302 | if (info->total_size > SZ_128M) { |
1303 | pr_warn("capping size to 128MiB\n"); | |
1304 | info->total_size = SZ_128M; | |
1305 | } | |
d26c3321 | 1306 | |
34327e9f WL |
1307 | if (!info->kmsg_size && !info->pmsg_size && !info->console_size && |
1308 | !info->ftrace_size) { | |
d26c3321 WL |
1309 | pr_warn("at least one record size must be non-zero\n"); |
1310 | return -EINVAL; | |
1311 | } | |
1312 | ||
1313 | if (!info->name || !info->name[0]) | |
1314 | return -EINVAL; | |
1315 | ||
1316 | #define check_size(name, size) { \ | |
1317 | if (info->name > 0 && info->name < (size)) { \ | |
1318 | pr_err(#name " must be over %d\n", (size)); \ | |
1319 | return -EINVAL; \ | |
1320 | } \ | |
1321 | if (info->name & (size - 1)) { \ | |
1322 | pr_err(#name " must be a multiple of %d\n", \ | |
1323 | (size)); \ | |
1324 | return -EINVAL; \ | |
1325 | } \ | |
1326 | } | |
1327 | ||
1328 | check_size(total_size, 4096); | |
1329 | check_size(kmsg_size, SECTOR_SIZE); | |
0dc06826 | 1330 | check_size(pmsg_size, SECTOR_SIZE); |
cc9c4d1b | 1331 | check_size(console_size, SECTOR_SIZE); |
34327e9f | 1332 | check_size(ftrace_size, SECTOR_SIZE); |
d26c3321 WL |
1333 | |
1334 | #undef check_size | |
1335 | ||
1336 | /* | |
1337 | * the @read and @write must be applied. | |
1338 | * if no @read, pstore may mount failed. | |
1339 | * if no @write, pstore do not support to remove record file. | |
1340 | */ | |
1341 | if (!info->read || !info->write) { | |
1342 | pr_err("no valid general read/write interface\n"); | |
1343 | return -EINVAL; | |
1344 | } | |
1345 | ||
1346 | mutex_lock(&cxt->pstore_zone_info_lock); | |
1347 | if (cxt->pstore_zone_info) { | |
1348 | pr_warn("'%s' already loaded: ignoring '%s'\n", | |
1349 | cxt->pstore_zone_info->name, info->name); | |
1350 | mutex_unlock(&cxt->pstore_zone_info_lock); | |
1351 | return -EBUSY; | |
1352 | } | |
1353 | cxt->pstore_zone_info = info; | |
1354 | ||
1355 | pr_debug("register %s with properties:\n", info->name); | |
1356 | pr_debug("\ttotal size : %ld Bytes\n", info->total_size); | |
1357 | pr_debug("\tkmsg size : %ld Bytes\n", info->kmsg_size); | |
0dc06826 | 1358 | pr_debug("\tpmsg size : %ld Bytes\n", info->pmsg_size); |
cc9c4d1b | 1359 | pr_debug("\tconsole size : %ld Bytes\n", info->console_size); |
34327e9f | 1360 | pr_debug("\tftrace size : %ld Bytes\n", info->ftrace_size); |
d26c3321 WL |
1361 | |
1362 | err = psz_alloc_zones(cxt); | |
1363 | if (err) { | |
1364 | pr_err("alloc zones failed\n"); | |
1365 | goto fail_out; | |
1366 | } | |
1367 | ||
1368 | if (info->kmsg_size) { | |
1369 | cxt->pstore.bufsize = cxt->kpszs[0]->buffer_size - | |
1370 | sizeof(struct psz_kmsg_header); | |
1371 | cxt->pstore.buf = kzalloc(cxt->pstore.bufsize, GFP_KERNEL); | |
1372 | if (!cxt->pstore.buf) { | |
1373 | err = -ENOMEM; | |
1374 | goto fail_free; | |
1375 | } | |
1376 | } | |
1377 | cxt->pstore.data = cxt; | |
1378 | ||
1379 | pr_info("registered %s as backend for", info->name); | |
1380 | cxt->pstore.max_reason = info->max_reason; | |
1381 | cxt->pstore.name = info->name; | |
1382 | if (info->kmsg_size) { | |
1383 | cxt->pstore.flags |= PSTORE_FLAGS_DMESG; | |
1384 | pr_cont(" kmsg(%s", | |
1385 | kmsg_dump_reason_str(cxt->pstore.max_reason)); | |
1386 | if (cxt->pstore_zone_info->panic_write) | |
1387 | pr_cont(",panic_write"); | |
1388 | pr_cont(")"); | |
1389 | } | |
0dc06826 WL |
1390 | if (info->pmsg_size) { |
1391 | cxt->pstore.flags |= PSTORE_FLAGS_PMSG; | |
1392 | pr_cont(" pmsg"); | |
1393 | } | |
cc9c4d1b WL |
1394 | if (info->console_size) { |
1395 | cxt->pstore.flags |= PSTORE_FLAGS_CONSOLE; | |
1396 | pr_cont(" console"); | |
1397 | } | |
34327e9f WL |
1398 | if (info->ftrace_size) { |
1399 | cxt->pstore.flags |= PSTORE_FLAGS_FTRACE; | |
1400 | pr_cont(" ftrace"); | |
1401 | } | |
d26c3321 WL |
1402 | pr_cont("\n"); |
1403 | ||
1404 | err = pstore_register(&cxt->pstore); | |
1405 | if (err) { | |
1406 | pr_err("registering with pstore failed\n"); | |
1407 | goto fail_free; | |
1408 | } | |
1409 | mutex_unlock(&pstore_zone_cxt.pstore_zone_info_lock); | |
1410 | ||
1411 | return 0; | |
1412 | ||
1413 | fail_free: | |
1414 | kfree(cxt->pstore.buf); | |
1415 | cxt->pstore.buf = NULL; | |
1416 | cxt->pstore.bufsize = 0; | |
1417 | psz_free_all_zones(cxt); | |
1418 | fail_out: | |
1419 | pstore_zone_cxt.pstore_zone_info = NULL; | |
1420 | mutex_unlock(&pstore_zone_cxt.pstore_zone_info_lock); | |
1421 | return err; | |
1422 | } | |
1423 | EXPORT_SYMBOL_GPL(register_pstore_zone); | |
1424 | ||
1425 | /** | |
1426 | * unregister_pstore_zone() - unregister to pstore/zone | |
1427 | * | |
1428 | * @info: back-end driver information. See struct pstore_zone_info. | |
1429 | */ | |
1430 | void unregister_pstore_zone(struct pstore_zone_info *info) | |
1431 | { | |
1432 | struct psz_context *cxt = &pstore_zone_cxt; | |
1433 | ||
1434 | mutex_lock(&cxt->pstore_zone_info_lock); | |
1435 | if (!cxt->pstore_zone_info) { | |
1436 | mutex_unlock(&cxt->pstore_zone_info_lock); | |
1437 | return; | |
1438 | } | |
1439 | ||
1440 | /* Stop incoming writes from pstore. */ | |
1441 | pstore_unregister(&cxt->pstore); | |
1442 | ||
cc9c4d1b WL |
1443 | /* Flush any pending writes. */ |
1444 | psz_flush_all_dirty_zones(NULL); | |
1445 | flush_delayed_work(&psz_cleaner); | |
1446 | ||
d26c3321 WL |
1447 | /* Clean up allocations. */ |
1448 | kfree(cxt->pstore.buf); | |
1449 | cxt->pstore.buf = NULL; | |
1450 | cxt->pstore.bufsize = 0; | |
1451 | cxt->pstore_zone_info = NULL; | |
1452 | ||
1453 | psz_free_all_zones(cxt); | |
1454 | ||
1455 | /* Clear counters and zone state. */ | |
1456 | cxt->oops_counter = 0; | |
1457 | cxt->panic_counter = 0; | |
1458 | atomic_set(&cxt->recovered, 0); | |
1459 | atomic_set(&cxt->on_panic, 0); | |
1460 | ||
1461 | mutex_unlock(&cxt->pstore_zone_info_lock); | |
1462 | } | |
1463 | EXPORT_SYMBOL_GPL(unregister_pstore_zone); | |
1464 | ||
1465 | MODULE_LICENSE("GPL"); | |
1466 | MODULE_AUTHOR("WeiXiong Liao <liaoweixiong@allwinnertech.com>"); | |
1467 | MODULE_AUTHOR("Kees Cook <keescook@chromium.org>"); | |
1468 | MODULE_DESCRIPTION("Storage Manager for pstore/blk"); |