Commit | Line | Data |
---|---|---|
ca01d6dd TL |
1 | /* |
2 | * Persistent Storage - platform driver interface parts. | |
3 | * | |
f29e5956 | 4 | * Copyright (C) 2007-2008 Google, Inc. |
ca01d6dd TL |
5 | * Copyright (C) 2010 Intel Corporation <tony.luck@intel.com> |
6 | * | |
7 | * This program is free software; you can redistribute it and/or modify | |
8 | * it under the terms of the GNU General Public License version 2 as | |
9 | * published by the Free Software Foundation. | |
10 | * | |
11 | * This program is distributed in the hope that it will be useful, | |
12 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
13 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
14 | * GNU General Public License for more details. | |
15 | * | |
16 | * You should have received a copy of the GNU General Public License | |
17 | * along with this program; if not, write to the Free Software | |
18 | * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA | |
19 | */ | |
20 | ||
ef748853 FF |
21 | #define pr_fmt(fmt) "pstore: " fmt |
22 | ||
ca01d6dd TL |
23 | #include <linux/atomic.h> |
24 | #include <linux/types.h> | |
25 | #include <linux/errno.h> | |
26 | #include <linux/init.h> | |
27 | #include <linux/kmsg_dump.h> | |
f29e5956 | 28 | #include <linux/console.h> |
ca01d6dd TL |
29 | #include <linux/module.h> |
30 | #include <linux/pstore.h> | |
8cfc8ddc GT |
31 | #ifdef CONFIG_PSTORE_LZO_COMPRESS |
32 | #include <linux/lzo.h> | |
33 | #endif | |
239b7161 | 34 | #if defined(CONFIG_PSTORE_LZ4_COMPRESS) || defined(CONFIG_PSTORE_LZ4HC_COMPRESS) |
8cfc8ddc GT |
35 | #include <linux/lz4.h> |
36 | #endif | |
cb3bee03 | 37 | #include <linux/crypto.h> |
ca01d6dd | 38 | #include <linux/string.h> |
6dda9266 | 39 | #include <linux/timer.h> |
ca01d6dd TL |
40 | #include <linux/slab.h> |
41 | #include <linux/uaccess.h> | |
a3f5f075 | 42 | #include <linux/jiffies.h> |
6dda9266 | 43 | #include <linux/workqueue.h> |
ca01d6dd TL |
44 | |
45 | #include "internal.h" | |
46 | ||
6dda9266 LT |
47 | /* |
48 | * We defer making "oops" entries appear in pstore - see | |
49 | * whether the system is actually still running well enough | |
50 | * to let someone see the entry | |
51 | */ | |
521f7288 | 52 | static int pstore_update_ms = -1; |
a3f5f075 AV |
53 | module_param_named(update_ms, pstore_update_ms, int, 0600); |
54 | MODULE_PARM_DESC(update_ms, "milliseconds before pstore updates its content " | |
521f7288 AV |
55 | "(default is -1, which means runtime updates are disabled; " |
56 | "enabling this option is not safe, it may lead to further " | |
57 | "corruption on Oopses)"); | |
6dda9266 LT |
58 | |
59 | static int pstore_new_entry; | |
60 | ||
24ed960a | 61 | static void pstore_timefunc(struct timer_list *); |
1d27e3e2 | 62 | static DEFINE_TIMER(pstore_timer, pstore_timefunc); |
6dda9266 LT |
63 | |
64 | static void pstore_dowork(struct work_struct *); | |
65 | static DECLARE_WORK(pstore_work, pstore_dowork); | |
66 | ||
ca01d6dd TL |
67 | /* |
68 | * pstore_lock just protects "psinfo" during | |
69 | * calls to pstore_register() | |
70 | */ | |
71 | static DEFINE_SPINLOCK(pstore_lock); | |
060287b8 | 72 | struct pstore_info *psinfo; |
ca01d6dd | 73 | |
dee28e72 | 74 | static char *backend; |
fe1d4758 KC |
75 | static char *compress = |
76 | #ifdef CONFIG_PSTORE_COMPRESS_DEFAULT | |
77 | CONFIG_PSTORE_COMPRESS_DEFAULT; | |
78 | #else | |
79 | NULL; | |
80 | #endif | |
dee28e72 | 81 | |
b0aad7a9 | 82 | /* Compression parameters */ |
cb3bee03 | 83 | static struct crypto_comp *tfm; |
8cfc8ddc GT |
84 | |
85 | struct pstore_zbackend { | |
cb3bee03 | 86 | int (*zbufsize)(size_t size); |
8cfc8ddc GT |
87 | const char *name; |
88 | }; | |
b0aad7a9 AB |
89 | |
90 | static char *big_oops_buf; | |
91 | static size_t big_oops_buf_sz; | |
92 | ||
366f7e7a | 93 | /* How much of the console log to snapshot */ |
349d7438 | 94 | unsigned long kmsg_bytes = PSTORE_DEFAULT_KMSG_BYTES; |
ca01d6dd | 95 | |
366f7e7a | 96 | void pstore_set_kmsg_bytes(int bytes) |
ca01d6dd | 97 | { |
366f7e7a | 98 | kmsg_bytes = bytes; |
ca01d6dd TL |
99 | } |
100 | ||
ca01d6dd TL |
101 | /* Tag each group of saved records with a sequence number */ |
102 | static int oopscount; | |
103 | ||
381b872c SA |
104 | static const char *get_reason_str(enum kmsg_dump_reason reason) |
105 | { | |
106 | switch (reason) { | |
107 | case KMSG_DUMP_PANIC: | |
108 | return "Panic"; | |
109 | case KMSG_DUMP_OOPS: | |
110 | return "Oops"; | |
111 | case KMSG_DUMP_EMERG: | |
112 | return "Emergency"; | |
113 | case KMSG_DUMP_RESTART: | |
114 | return "Restart"; | |
115 | case KMSG_DUMP_HALT: | |
116 | return "Halt"; | |
117 | case KMSG_DUMP_POWEROFF: | |
118 | return "Poweroff"; | |
119 | default: | |
120 | return "Unknown"; | |
121 | } | |
122 | } | |
9f6af27f | 123 | |
9f244e9c SA |
124 | bool pstore_cannot_block_path(enum kmsg_dump_reason reason) |
125 | { | |
126 | /* | |
127 | * In case of NMI path, pstore shouldn't be blocked | |
128 | * regardless of reason. | |
129 | */ | |
130 | if (in_nmi()) | |
131 | return true; | |
132 | ||
133 | switch (reason) { | |
134 | /* In panic case, other cpus are stopped by smp_send_stop(). */ | |
135 | case KMSG_DUMP_PANIC: | |
136 | /* Emergency restart shouldn't be blocked by spin lock. */ | |
137 | case KMSG_DUMP_EMERG: | |
138 | return true; | |
139 | default: | |
140 | return false; | |
141 | } | |
142 | } | |
143 | EXPORT_SYMBOL_GPL(pstore_cannot_block_path); | |
144 | ||
cb3bee03 GT |
145 | #ifdef CONFIG_PSTORE_DEFLATE_COMPRESS |
146 | static int zbufsize_deflate(size_t size) | |
adb42f5e | 147 | { |
7de8fe2f AB |
148 | size_t cmpr; |
149 | ||
cb3bee03 | 150 | switch (size) { |
7de8fe2f AB |
151 | /* buffer range for efivars */ |
152 | case 1000 ... 2000: | |
153 | cmpr = 56; | |
154 | break; | |
155 | case 2001 ... 3000: | |
156 | cmpr = 54; | |
157 | break; | |
158 | case 3001 ... 3999: | |
159 | cmpr = 52; | |
160 | break; | |
161 | /* buffer range for nvram, erst */ | |
162 | case 4000 ... 10000: | |
163 | cmpr = 45; | |
164 | break; | |
165 | default: | |
166 | cmpr = 60; | |
167 | break; | |
168 | } | |
b0aad7a9 | 169 | |
cb3bee03 | 170 | return (size * 100) / cmpr; |
8cfc8ddc | 171 | } |
8cfc8ddc GT |
172 | #endif |
173 | ||
174 | #ifdef CONFIG_PSTORE_LZO_COMPRESS | |
cb3bee03 | 175 | static int zbufsize_lzo(size_t size) |
8cfc8ddc | 176 | { |
cb3bee03 | 177 | return lzo1x_worst_compress(size); |
8cfc8ddc | 178 | } |
8cfc8ddc GT |
179 | #endif |
180 | ||
239b7161 | 181 | #if defined(CONFIG_PSTORE_LZ4_COMPRESS) || defined(CONFIG_PSTORE_LZ4HC_COMPRESS) |
cb3bee03 | 182 | static int zbufsize_lz4(size_t size) |
8cfc8ddc | 183 | { |
cb3bee03 | 184 | return LZ4_compressBound(size); |
8cfc8ddc | 185 | } |
239b7161 GT |
186 | #endif |
187 | ||
188 | #ifdef CONFIG_PSTORE_842_COMPRESS | |
cb3bee03 | 189 | static int zbufsize_842(size_t size) |
239b7161 | 190 | { |
55597406 | 191 | return size; |
239b7161 | 192 | } |
8cfc8ddc GT |
193 | #endif |
194 | ||
fe1d4758 KC |
195 | static const struct pstore_zbackend *zbackend __ro_after_init; |
196 | ||
197 | static const struct pstore_zbackend zbackends[] = { | |
cb3bee03 | 198 | #ifdef CONFIG_PSTORE_DEFLATE_COMPRESS |
fe1d4758 | 199 | { |
cb3bee03 GT |
200 | .zbufsize = zbufsize_deflate, |
201 | .name = "deflate", | |
fe1d4758 KC |
202 | }, |
203 | #endif | |
204 | #ifdef CONFIG_PSTORE_LZO_COMPRESS | |
205 | { | |
cb3bee03 | 206 | .zbufsize = zbufsize_lzo, |
fe1d4758 KC |
207 | .name = "lzo", |
208 | }, | |
209 | #endif | |
210 | #ifdef CONFIG_PSTORE_LZ4_COMPRESS | |
211 | { | |
cb3bee03 | 212 | .zbufsize = zbufsize_lz4, |
fe1d4758 KC |
213 | .name = "lz4", |
214 | }, | |
215 | #endif | |
216 | #ifdef CONFIG_PSTORE_LZ4HC_COMPRESS | |
217 | { | |
cb3bee03 | 218 | .zbufsize = zbufsize_lz4, |
fe1d4758 KC |
219 | .name = "lz4hc", |
220 | }, | |
8cfc8ddc | 221 | #endif |
fe1d4758 KC |
222 | #ifdef CONFIG_PSTORE_842_COMPRESS |
223 | { | |
cb3bee03 | 224 | .zbufsize = zbufsize_842, |
fe1d4758 KC |
225 | .name = "842", |
226 | }, | |
227 | #endif | |
228 | { } | |
229 | }; | |
8cfc8ddc GT |
230 | |
231 | static int pstore_compress(const void *in, void *out, | |
cb3bee03 | 232 | unsigned int inlen, unsigned int outlen) |
8cfc8ddc | 233 | { |
cb3bee03 GT |
234 | int ret; |
235 | ||
236 | ret = crypto_comp_compress(tfm, in, inlen, out, &outlen); | |
237 | if (ret) { | |
238 | pr_err("crypto_comp_compress failed, ret = %d!\n", ret); | |
239 | return ret; | |
240 | } | |
241 | ||
242 | return outlen; | |
8cfc8ddc GT |
243 | } |
244 | ||
cb3bee03 GT |
245 | static int pstore_decompress(void *in, void *out, |
246 | unsigned int inlen, unsigned int outlen) | |
8cfc8ddc | 247 | { |
cb3bee03 GT |
248 | int ret; |
249 | ||
250 | ret = crypto_comp_decompress(tfm, in, inlen, out, &outlen); | |
251 | if (ret) { | |
252 | pr_err("crypto_comp_decompress failed, ret = %d!\n", ret); | |
253 | return ret; | |
254 | } | |
255 | ||
256 | return outlen; | |
8cfc8ddc GT |
257 | } |
258 | ||
259 | static void allocate_buf_for_compression(void) | |
260 | { | |
cb3bee03 GT |
261 | if (!zbackend) |
262 | return; | |
263 | ||
264 | if (!crypto_has_comp(zbackend->name, 0, 0)) { | |
265 | pr_err("No %s compression\n", zbackend->name); | |
266 | return; | |
267 | } | |
268 | ||
269 | big_oops_buf_sz = zbackend->zbufsize(psinfo->bufsize); | |
270 | if (big_oops_buf_sz <= 0) | |
271 | return; | |
272 | ||
273 | big_oops_buf = kmalloc(big_oops_buf_sz, GFP_KERNEL); | |
274 | if (!big_oops_buf) { | |
8cfc8ddc | 275 | pr_err("allocate compression buffer error!\n"); |
cb3bee03 GT |
276 | return; |
277 | } | |
278 | ||
279 | tfm = crypto_alloc_comp(zbackend->name, 0, 0); | |
280 | if (IS_ERR_OR_NULL(tfm)) { | |
281 | kfree(big_oops_buf); | |
282 | big_oops_buf = NULL; | |
283 | pr_err("crypto_alloc_comp() failed!\n"); | |
284 | return; | |
8cfc8ddc GT |
285 | } |
286 | } | |
287 | ||
288 | static void free_buf_for_compression(void) | |
289 | { | |
cb3bee03 GT |
290 | if (!IS_ERR_OR_NULL(tfm)) |
291 | crypto_free_comp(tfm); | |
292 | kfree(big_oops_buf); | |
293 | big_oops_buf = NULL; | |
294 | big_oops_buf_sz = 0; | |
ee1d2674 GT |
295 | } |
296 | ||
b0aad7a9 AB |
297 | /* |
298 | * Called when compression fails, since the printk buffer | |
299 | * would be fetched for compression calling it again when | |
300 | * compression fails would have moved the iterator of | |
301 | * printk buffer which results in fetching old contents. | |
302 | * Copy the recent messages from big_oops_buf to psinfo->buf | |
303 | */ | |
304 | static size_t copy_kmsg_to_buffer(int hsize, size_t len) | |
305 | { | |
306 | size_t total_len; | |
307 | size_t diff; | |
308 | ||
309 | total_len = hsize + len; | |
310 | ||
311 | if (total_len > psinfo->bufsize) { | |
312 | diff = total_len - psinfo->bufsize + hsize; | |
313 | memcpy(psinfo->buf, big_oops_buf, hsize); | |
314 | memcpy(psinfo->buf + hsize, big_oops_buf + diff, | |
315 | psinfo->bufsize - hsize); | |
316 | total_len = psinfo->bufsize; | |
317 | } else | |
318 | memcpy(psinfo->buf, big_oops_buf, total_len); | |
319 | ||
320 | return total_len; | |
321 | } | |
322 | ||
e581ca81 KC |
323 | void pstore_record_init(struct pstore_record *record, |
324 | struct pstore_info *psinfo) | |
325 | { | |
326 | memset(record, 0, sizeof(*record)); | |
327 | ||
328 | record->psi = psinfo; | |
c7f3c595 KC |
329 | |
330 | /* Report zeroed timestamp if called before timekeeping has resumed. */ | |
df27067e | 331 | record->time = ns_to_timespec(ktime_get_real_fast_ns()); |
e581ca81 KC |
332 | } |
333 | ||
ca01d6dd TL |
334 | /* |
335 | * callback from kmsg_dump. (s2,l2) has the most recently | |
336 | * written bytes, older bytes are in (s1,l1). Save as much | |
337 | * as we can from the end of the buffer. | |
338 | */ | |
339 | static void pstore_dump(struct kmsg_dumper *dumper, | |
e2ae715d | 340 | enum kmsg_dump_reason reason) |
ca01d6dd | 341 | { |
e2ae715d | 342 | unsigned long total = 0; |
381b872c | 343 | const char *why; |
b94fdd07 | 344 | unsigned int part = 1; |
abd4d558 | 345 | unsigned long flags = 0; |
98e44fda | 346 | int is_locked; |
e2ae715d | 347 | int ret; |
ca01d6dd | 348 | |
381b872c | 349 | why = get_reason_str(reason); |
9f6af27f | 350 | |
9f244e9c SA |
351 | if (pstore_cannot_block_path(reason)) { |
352 | is_locked = spin_trylock_irqsave(&psinfo->buf_lock, flags); | |
353 | if (!is_locked) { | |
354 | pr_err("pstore dump routine blocked in %s path, may corrupt error record\n" | |
355 | , in_nmi() ? "NMI" : why); | |
959217c8 | 356 | return; |
9f244e9c | 357 | } |
98e44fda | 358 | } else { |
abd4d558 | 359 | spin_lock_irqsave(&psinfo->buf_lock, flags); |
98e44fda NK |
360 | is_locked = 1; |
361 | } | |
ca01d6dd TL |
362 | oopscount++; |
363 | while (total < kmsg_bytes) { | |
e2ae715d | 364 | char *dst; |
76cc9580 KC |
365 | size_t dst_size; |
366 | int header_size; | |
b0aad7a9 | 367 | int zipped_len = -1; |
76cc9580 | 368 | size_t dump_size; |
e581ca81 KC |
369 | struct pstore_record record; |
370 | ||
371 | pstore_record_init(&record, psinfo); | |
372 | record.type = PSTORE_TYPE_DMESG; | |
373 | record.count = oopscount; | |
374 | record.reason = reason; | |
375 | record.part = part; | |
376 | record.buf = psinfo->buf; | |
e2ae715d | 377 | |
f0e2efcf | 378 | if (big_oops_buf && is_locked) { |
b0aad7a9 | 379 | dst = big_oops_buf; |
76cc9580 | 380 | dst_size = big_oops_buf_sz; |
235f6d15 NK |
381 | } else { |
382 | dst = psinfo->buf; | |
76cc9580 | 383 | dst_size = psinfo->bufsize; |
235f6d15 NK |
384 | } |
385 | ||
76cc9580 KC |
386 | /* Write dump header. */ |
387 | header_size = snprintf(dst, dst_size, "%s#%d Part%u\n", why, | |
388 | oopscount, part); | |
389 | dst_size -= header_size; | |
ca01d6dd | 390 | |
76cc9580 KC |
391 | /* Write dump contents. */ |
392 | if (!kmsg_dump_get_buffer(dumper, true, dst + header_size, | |
393 | dst_size, &dump_size)) | |
235f6d15 | 394 | break; |
b0aad7a9 | 395 | |
235f6d15 | 396 | if (big_oops_buf && is_locked) { |
b0aad7a9 | 397 | zipped_len = pstore_compress(dst, psinfo->buf, |
76cc9580 KC |
398 | header_size + dump_size, |
399 | psinfo->bufsize); | |
b0aad7a9 AB |
400 | |
401 | if (zipped_len > 0) { | |
76cc9580 KC |
402 | record.compressed = true; |
403 | record.size = zipped_len; | |
b0aad7a9 | 404 | } else { |
76cc9580 KC |
405 | record.size = copy_kmsg_to_buffer(header_size, |
406 | dump_size); | |
b0aad7a9 AB |
407 | } |
408 | } else { | |
76cc9580 | 409 | record.size = header_size + dump_size; |
b0aad7a9 | 410 | } |
ca01d6dd | 411 | |
76cc9580 | 412 | ret = psinfo->write(&record); |
b238b8fa | 413 | if (ret == 0 && reason == KMSG_DUMP_OOPS && pstore_is_mounted()) |
6dda9266 | 414 | pstore_new_entry = 1; |
e2ae715d | 415 | |
76cc9580 | 416 | total += record.size; |
56280682 | 417 | part++; |
ca01d6dd | 418 | } |
98e44fda | 419 | if (is_locked) |
abd4d558 | 420 | spin_unlock_irqrestore(&psinfo->buf_lock, flags); |
ca01d6dd TL |
421 | } |
422 | ||
423 | static struct kmsg_dumper pstore_dumper = { | |
424 | .dump = pstore_dump, | |
425 | }; | |
426 | ||
306e5c2a GT |
427 | /* |
428 | * Register with kmsg_dump to save last part of console log on panic. | |
429 | */ | |
18730411 GT |
430 | static void pstore_register_kmsg(void) |
431 | { | |
432 | kmsg_dump_register(&pstore_dumper); | |
433 | } | |
434 | ||
ee1d2674 GT |
435 | static void pstore_unregister_kmsg(void) |
436 | { | |
437 | kmsg_dump_unregister(&pstore_dumper); | |
438 | } | |
439 | ||
f29e5956 AV |
440 | #ifdef CONFIG_PSTORE_CONSOLE |
441 | static void pstore_console_write(struct console *con, const char *s, unsigned c) | |
442 | { | |
443 | const char *e = s + c; | |
444 | ||
445 | while (s < e) { | |
e581ca81 | 446 | struct pstore_record record; |
f29e5956 AV |
447 | unsigned long flags; |
448 | ||
e581ca81 KC |
449 | pstore_record_init(&record, psinfo); |
450 | record.type = PSTORE_TYPE_CONSOLE; | |
451 | ||
f29e5956 AV |
452 | if (c > psinfo->bufsize) |
453 | c = psinfo->bufsize; | |
80c9d03c CL |
454 | |
455 | if (oops_in_progress) { | |
456 | if (!spin_trylock_irqsave(&psinfo->buf_lock, flags)) | |
457 | break; | |
458 | } else { | |
459 | spin_lock_irqsave(&psinfo->buf_lock, flags); | |
460 | } | |
b10b4711 KC |
461 | record.buf = (char *)s; |
462 | record.size = c; | |
4c9ec219 | 463 | psinfo->write(&record); |
f29e5956 AV |
464 | spin_unlock_irqrestore(&psinfo->buf_lock, flags); |
465 | s += c; | |
466 | c = e - s; | |
467 | } | |
468 | } | |
469 | ||
470 | static struct console pstore_console = { | |
471 | .name = "pstore", | |
472 | .write = pstore_console_write, | |
473 | .flags = CON_PRINTBUFFER | CON_ENABLED | CON_ANYTIME, | |
474 | .index = -1, | |
475 | }; | |
476 | ||
477 | static void pstore_register_console(void) | |
478 | { | |
479 | register_console(&pstore_console); | |
480 | } | |
ee1d2674 GT |
481 | |
482 | static void pstore_unregister_console(void) | |
483 | { | |
484 | unregister_console(&pstore_console); | |
485 | } | |
f29e5956 AV |
486 | #else |
487 | static void pstore_register_console(void) {} | |
ee1d2674 | 488 | static void pstore_unregister_console(void) {} |
f29e5956 AV |
489 | #endif |
490 | ||
4c9ec219 KC |
491 | static int pstore_write_user_compat(struct pstore_record *record, |
492 | const char __user *buf) | |
5bf6d1b9 | 493 | { |
30800d99 KC |
494 | int ret = 0; |
495 | ||
496 | if (record->buf) | |
497 | return -EINVAL; | |
498 | ||
077090af | 499 | record->buf = memdup_user(buf, record->size); |
dfd6fa39 | 500 | if (IS_ERR(record->buf)) { |
077090af | 501 | ret = PTR_ERR(record->buf); |
30800d99 | 502 | goto out; |
5bf6d1b9 | 503 | } |
30800d99 KC |
504 | |
505 | ret = record->psi->write(record); | |
506 | ||
30800d99 | 507 | kfree(record->buf); |
077090af | 508 | out: |
30800d99 KC |
509 | record->buf = NULL; |
510 | ||
511 | return unlikely(ret < 0) ? ret : record->size; | |
5bf6d1b9 MS |
512 | } |
513 | ||
ca01d6dd TL |
514 | /* |
515 | * platform specific persistent storage driver registers with | |
516 | * us here. If pstore is already mounted, call the platform | |
517 | * read function right away to populate the file system. If not | |
518 | * then the pstore mount code will call us later to fill out | |
519 | * the file system. | |
ca01d6dd TL |
520 | */ |
521 | int pstore_register(struct pstore_info *psi) | |
522 | { | |
523 | struct module *owner = psi->owner; | |
524 | ||
0d7cd09a KC |
525 | if (backend && strcmp(backend, psi->name)) { |
526 | pr_warn("ignoring unexpected backend '%s'\n", psi->name); | |
8e48b1a8 | 527 | return -EPERM; |
0d7cd09a | 528 | } |
8e48b1a8 | 529 | |
4c9ec219 KC |
530 | /* Sanity check flags. */ |
531 | if (!psi->flags) { | |
532 | pr_warn("backend '%s' must support at least one frontend\n", | |
533 | psi->name); | |
534 | return -EINVAL; | |
535 | } | |
536 | ||
537 | /* Check for required functions. */ | |
538 | if (!psi->read || !psi->write) { | |
539 | pr_warn("backend '%s' must implement read() and write()\n", | |
540 | psi->name); | |
541 | return -EINVAL; | |
542 | } | |
543 | ||
ca01d6dd TL |
544 | spin_lock(&pstore_lock); |
545 | if (psinfo) { | |
0d7cd09a KC |
546 | pr_warn("backend '%s' already loaded: ignoring '%s'\n", |
547 | psinfo->name, psi->name); | |
ca01d6dd TL |
548 | spin_unlock(&pstore_lock); |
549 | return -EBUSY; | |
550 | } | |
dee28e72 | 551 | |
4c9ec219 KC |
552 | if (!psi->write_user) |
553 | psi->write_user = pstore_write_user_compat; | |
ca01d6dd | 554 | psinfo = psi; |
f6f82851 | 555 | mutex_init(&psinfo->read_mutex); |
ca01d6dd TL |
556 | spin_unlock(&pstore_lock); |
557 | ||
558 | if (owner && !try_module_get(owner)) { | |
559 | psinfo = NULL; | |
560 | return -EINVAL; | |
561 | } | |
562 | ||
b0aad7a9 AB |
563 | allocate_buf_for_compression(); |
564 | ||
ca01d6dd | 565 | if (pstore_is_mounted()) |
6dda9266 | 566 | pstore_get_records(0); |
ca01d6dd | 567 | |
c950fd6f NK |
568 | if (psi->flags & PSTORE_FLAGS_DMESG) |
569 | pstore_register_kmsg(); | |
570 | if (psi->flags & PSTORE_FLAGS_CONSOLE) | |
df36ac1b | 571 | pstore_register_console(); |
c950fd6f | 572 | if (psi->flags & PSTORE_FLAGS_FTRACE) |
df36ac1b | 573 | pstore_register_ftrace(); |
c950fd6f | 574 | if (psi->flags & PSTORE_FLAGS_PMSG) |
9d5438f4 | 575 | pstore_register_pmsg(); |
ca01d6dd | 576 | |
6330d553 | 577 | /* Start watching for new records, if desired. */ |
a3f5f075 AV |
578 | if (pstore_update_ms >= 0) { |
579 | pstore_timer.expires = jiffies + | |
580 | msecs_to_jiffies(pstore_update_ms); | |
581 | add_timer(&pstore_timer); | |
582 | } | |
6dda9266 | 583 | |
42222c2a WL |
584 | /* |
585 | * Update the module parameter backend, so it is visible | |
586 | * through /sys/module/pstore/parameters/backend | |
587 | */ | |
588 | backend = psi->name; | |
589 | ||
ef748853 | 590 | pr_info("Registered %s as persistent store backend\n", psi->name); |
8e48b1a8 | 591 | |
1344dd86 KC |
592 | module_put(owner); |
593 | ||
ca01d6dd TL |
594 | return 0; |
595 | } | |
596 | EXPORT_SYMBOL_GPL(pstore_register); | |
597 | ||
ee1d2674 GT |
598 | void pstore_unregister(struct pstore_info *psi) |
599 | { | |
6330d553 KC |
600 | /* Stop timer and make sure all work has finished. */ |
601 | pstore_update_ms = -1; | |
602 | del_timer_sync(&pstore_timer); | |
603 | flush_work(&pstore_work); | |
604 | ||
c950fd6f | 605 | if (psi->flags & PSTORE_FLAGS_PMSG) |
a1db8060 | 606 | pstore_unregister_pmsg(); |
c950fd6f | 607 | if (psi->flags & PSTORE_FLAGS_FTRACE) |
a1db8060 | 608 | pstore_unregister_ftrace(); |
c950fd6f | 609 | if (psi->flags & PSTORE_FLAGS_CONSOLE) |
a1db8060 | 610 | pstore_unregister_console(); |
c950fd6f NK |
611 | if (psi->flags & PSTORE_FLAGS_DMESG) |
612 | pstore_unregister_kmsg(); | |
ee1d2674 GT |
613 | |
614 | free_buf_for_compression(); | |
615 | ||
616 | psinfo = NULL; | |
617 | backend = NULL; | |
618 | } | |
619 | EXPORT_SYMBOL_GPL(pstore_unregister); | |
620 | ||
634f8f51 KC |
621 | static void decompress_record(struct pstore_record *record) |
622 | { | |
623 | int unzipped_len; | |
7e8cc8dc | 624 | char *decompressed; |
634f8f51 | 625 | |
4a16d1cb AK |
626 | if (!record->compressed) |
627 | return; | |
628 | ||
634f8f51 | 629 | /* Only PSTORE_TYPE_DMESG support compression. */ |
4a16d1cb | 630 | if (record->type != PSTORE_TYPE_DMESG) { |
634f8f51 KC |
631 | pr_warn("ignored compressed record type %d\n", record->type); |
632 | return; | |
633 | } | |
634 | ||
635 | /* No compression method has created the common buffer. */ | |
636 | if (!big_oops_buf) { | |
637 | pr_warn("no decompression buffer allocated\n"); | |
638 | return; | |
639 | } | |
640 | ||
641 | unzipped_len = pstore_decompress(record->buf, big_oops_buf, | |
642 | record->size, big_oops_buf_sz); | |
7e8cc8dc | 643 | if (unzipped_len <= 0) { |
634f8f51 | 644 | pr_err("decompression failed: %d\n", unzipped_len); |
7e8cc8dc KC |
645 | return; |
646 | } | |
647 | ||
648 | /* Build new buffer for decompressed contents. */ | |
649 | decompressed = kmalloc(unzipped_len + record->ecc_notice_size, | |
650 | GFP_KERNEL); | |
651 | if (!decompressed) { | |
652 | pr_err("decompression ran out of memory\n"); | |
653 | return; | |
654 | } | |
655 | memcpy(decompressed, big_oops_buf, unzipped_len); | |
656 | ||
657 | /* Append ECC notice to decompressed buffer. */ | |
658 | memcpy(decompressed + unzipped_len, record->buf + record->size, | |
659 | record->ecc_notice_size); | |
660 | ||
661 | /* Swap out compresed contents with decompressed contents. */ | |
662 | kfree(record->buf); | |
663 | record->buf = decompressed; | |
664 | record->size = unzipped_len; | |
665 | record->compressed = false; | |
634f8f51 KC |
666 | } |
667 | ||
ca01d6dd | 668 | /* |
3a7d2fd1 | 669 | * Read all the records from one persistent store backend. Create |
6dda9266 LT |
670 | * files in our filesystem. Don't warn about -EEXIST errors |
671 | * when we are re-scanning the backing store looking to add new | |
672 | * error records. | |
ca01d6dd | 673 | */ |
3a7d2fd1 KC |
674 | void pstore_get_backend_records(struct pstore_info *psi, |
675 | struct dentry *root, int quiet) | |
ca01d6dd | 676 | { |
2a2b0acf | 677 | int failed = 0; |
656de42e | 678 | unsigned int stop_loop = 65536; |
ca01d6dd | 679 | |
3a7d2fd1 | 680 | if (!psi || !root) |
ca01d6dd TL |
681 | return; |
682 | ||
f6f82851 | 683 | mutex_lock(&psi->read_mutex); |
2174f6df | 684 | if (psi->open && psi->open(psi)) |
06cf91b4 CG |
685 | goto out; |
686 | ||
1dfff7dd KC |
687 | /* |
688 | * Backend callback read() allocates record.buf. decompress_record() | |
689 | * may reallocate record.buf. On success, pstore_mkfile() will keep | |
690 | * the record.buf, so free it only on failure. | |
691 | */ | |
656de42e | 692 | for (; stop_loop; stop_loop--) { |
2a2b0acf KC |
693 | struct pstore_record *record; |
694 | int rc; | |
695 | ||
696 | record = kzalloc(sizeof(*record), GFP_KERNEL); | |
697 | if (!record) { | |
698 | pr_err("out of memory creating record\n"); | |
699 | break; | |
700 | } | |
e581ca81 | 701 | pstore_record_init(record, psi); |
2a2b0acf KC |
702 | |
703 | record->size = psi->read(record); | |
704 | ||
705 | /* No more records left in backend? */ | |
f6525b96 DA |
706 | if (record->size <= 0) { |
707 | kfree(record); | |
2a2b0acf | 708 | break; |
f6525b96 | 709 | } |
2a2b0acf KC |
710 | |
711 | decompress_record(record); | |
3a7d2fd1 | 712 | rc = pstore_mkfile(root, record); |
1dfff7dd | 713 | if (rc) { |
83f70f07 | 714 | /* pstore_mkfile() did not take record, so free it. */ |
2a2b0acf | 715 | kfree(record->buf); |
83f70f07 | 716 | kfree(record); |
1dfff7dd KC |
717 | if (rc != -EEXIST || !quiet) |
718 | failed++; | |
719 | } | |
ca01d6dd | 720 | } |
2174f6df KC |
721 | if (psi->close) |
722 | psi->close(psi); | |
06cf91b4 | 723 | out: |
f6f82851 | 724 | mutex_unlock(&psi->read_mutex); |
ca01d6dd TL |
725 | |
726 | if (failed) | |
656de42e | 727 | pr_warn("failed to create %d record(s) from '%s'\n", |
ef748853 | 728 | failed, psi->name); |
656de42e KC |
729 | if (!stop_loop) |
730 | pr_err("looping? Too many records seen from '%s'\n", | |
731 | psi->name); | |
ca01d6dd TL |
732 | } |
733 | ||
6dda9266 LT |
734 | static void pstore_dowork(struct work_struct *work) |
735 | { | |
736 | pstore_get_records(1); | |
737 | } | |
738 | ||
24ed960a | 739 | static void pstore_timefunc(struct timer_list *unused) |
6dda9266 LT |
740 | { |
741 | if (pstore_new_entry) { | |
742 | pstore_new_entry = 0; | |
743 | schedule_work(&pstore_work); | |
744 | } | |
745 | ||
6330d553 KC |
746 | if (pstore_update_ms >= 0) |
747 | mod_timer(&pstore_timer, | |
748 | jiffies + msecs_to_jiffies(pstore_update_ms)); | |
6dda9266 LT |
749 | } |
750 | ||
fe1d4758 KC |
751 | void __init pstore_choose_compression(void) |
752 | { | |
753 | const struct pstore_zbackend *step; | |
754 | ||
755 | if (!compress) | |
756 | return; | |
757 | ||
758 | for (step = zbackends; step->name; step++) { | |
759 | if (!strcmp(compress, step->name)) { | |
760 | zbackend = step; | |
761 | pr_info("using %s compression\n", zbackend->name); | |
762 | return; | |
763 | } | |
764 | } | |
765 | } | |
766 | ||
767 | module_param(compress, charp, 0444); | |
768 | MODULE_PARM_DESC(compress, "Pstore compression to use"); | |
769 | ||
dee28e72 MG |
770 | module_param(backend, charp, 0444); |
771 | MODULE_PARM_DESC(backend, "Pstore backend to use"); |