Commit | Line | Data |
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45051539 | 1 | // SPDX-License-Identifier: GPL-2.0-only |
ca01d6dd TL |
2 | /* |
3 | * Persistent Storage - platform driver interface parts. | |
4 | * | |
f29e5956 | 5 | * Copyright (C) 2007-2008 Google, Inc. |
ca01d6dd | 6 | * Copyright (C) 2010 Intel Corporation <tony.luck@intel.com> |
ca01d6dd TL |
7 | */ |
8 | ||
ef748853 FF |
9 | #define pr_fmt(fmt) "pstore: " fmt |
10 | ||
ca01d6dd TL |
11 | #include <linux/atomic.h> |
12 | #include <linux/types.h> | |
13 | #include <linux/errno.h> | |
14 | #include <linux/init.h> | |
15 | #include <linux/kmsg_dump.h> | |
f29e5956 | 16 | #include <linux/console.h> |
ca01d6dd TL |
17 | #include <linux/module.h> |
18 | #include <linux/pstore.h> | |
58eb5b67 | 19 | #if IS_ENABLED(CONFIG_PSTORE_LZO_COMPRESS) |
8cfc8ddc GT |
20 | #include <linux/lzo.h> |
21 | #endif | |
58eb5b67 | 22 | #if IS_ENABLED(CONFIG_PSTORE_LZ4_COMPRESS) || IS_ENABLED(CONFIG_PSTORE_LZ4HC_COMPRESS) |
8cfc8ddc GT |
23 | #include <linux/lz4.h> |
24 | #endif | |
1021bcf4 GT |
25 | #if IS_ENABLED(CONFIG_PSTORE_ZSTD_COMPRESS) |
26 | #include <linux/zstd.h> | |
27 | #endif | |
cb3bee03 | 28 | #include <linux/crypto.h> |
ca01d6dd | 29 | #include <linux/string.h> |
6dda9266 | 30 | #include <linux/timer.h> |
ca01d6dd TL |
31 | #include <linux/slab.h> |
32 | #include <linux/uaccess.h> | |
a3f5f075 | 33 | #include <linux/jiffies.h> |
6dda9266 | 34 | #include <linux/workqueue.h> |
ca01d6dd TL |
35 | |
36 | #include "internal.h" | |
37 | ||
6dda9266 LT |
38 | /* |
39 | * We defer making "oops" entries appear in pstore - see | |
40 | * whether the system is actually still running well enough | |
41 | * to let someone see the entry | |
42 | */ | |
521f7288 | 43 | static int pstore_update_ms = -1; |
a3f5f075 AV |
44 | module_param_named(update_ms, pstore_update_ms, int, 0600); |
45 | MODULE_PARM_DESC(update_ms, "milliseconds before pstore updates its content " | |
521f7288 | 46 | "(default is -1, which means runtime updates are disabled; " |
78c83c82 | 47 | "enabling this option may not be safe; it may lead to further " |
521f7288 | 48 | "corruption on Oopses)"); |
6dda9266 | 49 | |
f0f23e54 JFG |
50 | /* Names should be in the same order as the enum pstore_type_id */ |
51 | static const char * const pstore_type_names[] = { | |
52 | "dmesg", | |
53 | "mce", | |
54 | "console", | |
55 | "ftrace", | |
56 | "rtas", | |
57 | "powerpc-ofw", | |
58 | "powerpc-common", | |
59 | "pmsg", | |
60 | "powerpc-opal", | |
61 | }; | |
62 | ||
6dda9266 LT |
63 | static int pstore_new_entry; |
64 | ||
24ed960a | 65 | static void pstore_timefunc(struct timer_list *); |
1d27e3e2 | 66 | static DEFINE_TIMER(pstore_timer, pstore_timefunc); |
6dda9266 LT |
67 | |
68 | static void pstore_dowork(struct work_struct *); | |
69 | static DECLARE_WORK(pstore_work, pstore_dowork); | |
70 | ||
ca01d6dd | 71 | /* |
6248a066 KC |
72 | * psinfo_lock protects "psinfo" during calls to |
73 | * pstore_register(), pstore_unregister(), and | |
74 | * the filesystem mount/unmount routines. | |
ca01d6dd | 75 | */ |
cab12fd0 | 76 | static DEFINE_MUTEX(psinfo_lock); |
060287b8 | 77 | struct pstore_info *psinfo; |
ca01d6dd | 78 | |
dee28e72 | 79 | static char *backend; |
d973f7d8 KC |
80 | module_param(backend, charp, 0444); |
81 | MODULE_PARM_DESC(backend, "specific backend to use"); | |
82 | ||
fe1d4758 KC |
83 | static char *compress = |
84 | #ifdef CONFIG_PSTORE_COMPRESS_DEFAULT | |
85 | CONFIG_PSTORE_COMPRESS_DEFAULT; | |
86 | #else | |
87 | NULL; | |
88 | #endif | |
d973f7d8 KC |
89 | module_param(compress, charp, 0444); |
90 | MODULE_PARM_DESC(compress, "compression to use"); | |
dee28e72 | 91 | |
b0aad7a9 | 92 | /* Compression parameters */ |
cb3bee03 | 93 | static struct crypto_comp *tfm; |
8cfc8ddc GT |
94 | |
95 | struct pstore_zbackend { | |
cb3bee03 | 96 | int (*zbufsize)(size_t size); |
8cfc8ddc GT |
97 | const char *name; |
98 | }; | |
b0aad7a9 AB |
99 | |
100 | static char *big_oops_buf; | |
101 | static size_t big_oops_buf_sz; | |
102 | ||
366f7e7a | 103 | /* How much of the console log to snapshot */ |
349d7438 | 104 | unsigned long kmsg_bytes = PSTORE_DEFAULT_KMSG_BYTES; |
ca01d6dd | 105 | |
366f7e7a | 106 | void pstore_set_kmsg_bytes(int bytes) |
ca01d6dd | 107 | { |
366f7e7a | 108 | kmsg_bytes = bytes; |
ca01d6dd TL |
109 | } |
110 | ||
ca01d6dd TL |
111 | /* Tag each group of saved records with a sequence number */ |
112 | static int oopscount; | |
113 | ||
f0f23e54 JFG |
114 | const char *pstore_type_to_name(enum pstore_type_id type) |
115 | { | |
116 | BUILD_BUG_ON(ARRAY_SIZE(pstore_type_names) != PSTORE_TYPE_MAX); | |
117 | ||
118 | if (WARN_ON_ONCE(type >= PSTORE_TYPE_MAX)) | |
119 | return "unknown"; | |
120 | ||
121 | return pstore_type_names[type]; | |
122 | } | |
123 | EXPORT_SYMBOL_GPL(pstore_type_to_name); | |
124 | ||
125 | enum pstore_type_id pstore_name_to_type(const char *name) | |
126 | { | |
127 | int i; | |
128 | ||
129 | for (i = 0; i < PSTORE_TYPE_MAX; i++) { | |
130 | if (!strcmp(pstore_type_names[i], name)) | |
131 | return i; | |
132 | } | |
133 | ||
134 | return PSTORE_TYPE_MAX; | |
135 | } | |
136 | EXPORT_SYMBOL_GPL(pstore_name_to_type); | |
137 | ||
78c83c82 KC |
138 | static void pstore_timer_kick(void) |
139 | { | |
140 | if (pstore_update_ms < 0) | |
141 | return; | |
142 | ||
143 | mod_timer(&pstore_timer, jiffies + msecs_to_jiffies(pstore_update_ms)); | |
144 | } | |
145 | ||
ea84b580 KC |
146 | /* |
147 | * Should pstore_dump() wait for a concurrent pstore_dump()? If | |
148 | * not, the current pstore_dump() will report a failure to dump | |
149 | * and return. | |
150 | */ | |
151 | static bool pstore_cannot_wait(enum kmsg_dump_reason reason) | |
9f244e9c | 152 | { |
ea84b580 | 153 | /* In NMI path, pstore shouldn't block regardless of reason. */ |
9f244e9c SA |
154 | if (in_nmi()) |
155 | return true; | |
156 | ||
157 | switch (reason) { | |
158 | /* In panic case, other cpus are stopped by smp_send_stop(). */ | |
159 | case KMSG_DUMP_PANIC: | |
ea84b580 | 160 | /* Emergency restart shouldn't be blocked. */ |
9f244e9c SA |
161 | case KMSG_DUMP_EMERG: |
162 | return true; | |
163 | default: | |
164 | return false; | |
165 | } | |
166 | } | |
9f244e9c | 167 | |
58eb5b67 | 168 | #if IS_ENABLED(CONFIG_PSTORE_DEFLATE_COMPRESS) |
cb3bee03 | 169 | static int zbufsize_deflate(size_t size) |
adb42f5e | 170 | { |
7de8fe2f AB |
171 | size_t cmpr; |
172 | ||
cb3bee03 | 173 | switch (size) { |
7de8fe2f AB |
174 | /* buffer range for efivars */ |
175 | case 1000 ... 2000: | |
176 | cmpr = 56; | |
177 | break; | |
178 | case 2001 ... 3000: | |
179 | cmpr = 54; | |
180 | break; | |
181 | case 3001 ... 3999: | |
182 | cmpr = 52; | |
183 | break; | |
184 | /* buffer range for nvram, erst */ | |
185 | case 4000 ... 10000: | |
186 | cmpr = 45; | |
187 | break; | |
188 | default: | |
189 | cmpr = 60; | |
190 | break; | |
191 | } | |
b0aad7a9 | 192 | |
cb3bee03 | 193 | return (size * 100) / cmpr; |
8cfc8ddc | 194 | } |
8cfc8ddc GT |
195 | #endif |
196 | ||
58eb5b67 | 197 | #if IS_ENABLED(CONFIG_PSTORE_LZO_COMPRESS) |
cb3bee03 | 198 | static int zbufsize_lzo(size_t size) |
8cfc8ddc | 199 | { |
cb3bee03 | 200 | return lzo1x_worst_compress(size); |
8cfc8ddc | 201 | } |
8cfc8ddc GT |
202 | #endif |
203 | ||
58eb5b67 | 204 | #if IS_ENABLED(CONFIG_PSTORE_LZ4_COMPRESS) || IS_ENABLED(CONFIG_PSTORE_LZ4HC_COMPRESS) |
cb3bee03 | 205 | static int zbufsize_lz4(size_t size) |
8cfc8ddc | 206 | { |
cb3bee03 | 207 | return LZ4_compressBound(size); |
8cfc8ddc | 208 | } |
239b7161 GT |
209 | #endif |
210 | ||
58eb5b67 | 211 | #if IS_ENABLED(CONFIG_PSTORE_842_COMPRESS) |
cb3bee03 | 212 | static int zbufsize_842(size_t size) |
239b7161 | 213 | { |
55597406 | 214 | return size; |
239b7161 | 215 | } |
8cfc8ddc GT |
216 | #endif |
217 | ||
1021bcf4 GT |
218 | #if IS_ENABLED(CONFIG_PSTORE_ZSTD_COMPRESS) |
219 | static int zbufsize_zstd(size_t size) | |
220 | { | |
221 | return ZSTD_compressBound(size); | |
222 | } | |
223 | #endif | |
224 | ||
fe1d4758 KC |
225 | static const struct pstore_zbackend *zbackend __ro_after_init; |
226 | ||
227 | static const struct pstore_zbackend zbackends[] = { | |
58eb5b67 | 228 | #if IS_ENABLED(CONFIG_PSTORE_DEFLATE_COMPRESS) |
fe1d4758 | 229 | { |
cb3bee03 GT |
230 | .zbufsize = zbufsize_deflate, |
231 | .name = "deflate", | |
fe1d4758 KC |
232 | }, |
233 | #endif | |
58eb5b67 | 234 | #if IS_ENABLED(CONFIG_PSTORE_LZO_COMPRESS) |
fe1d4758 | 235 | { |
cb3bee03 | 236 | .zbufsize = zbufsize_lzo, |
fe1d4758 KC |
237 | .name = "lzo", |
238 | }, | |
239 | #endif | |
58eb5b67 | 240 | #if IS_ENABLED(CONFIG_PSTORE_LZ4_COMPRESS) |
fe1d4758 | 241 | { |
cb3bee03 | 242 | .zbufsize = zbufsize_lz4, |
fe1d4758 KC |
243 | .name = "lz4", |
244 | }, | |
245 | #endif | |
58eb5b67 | 246 | #if IS_ENABLED(CONFIG_PSTORE_LZ4HC_COMPRESS) |
fe1d4758 | 247 | { |
cb3bee03 | 248 | .zbufsize = zbufsize_lz4, |
fe1d4758 KC |
249 | .name = "lz4hc", |
250 | }, | |
8cfc8ddc | 251 | #endif |
58eb5b67 | 252 | #if IS_ENABLED(CONFIG_PSTORE_842_COMPRESS) |
fe1d4758 | 253 | { |
cb3bee03 | 254 | .zbufsize = zbufsize_842, |
fe1d4758 KC |
255 | .name = "842", |
256 | }, | |
1021bcf4 GT |
257 | #endif |
258 | #if IS_ENABLED(CONFIG_PSTORE_ZSTD_COMPRESS) | |
259 | { | |
260 | .zbufsize = zbufsize_zstd, | |
261 | .name = "zstd", | |
262 | }, | |
fe1d4758 KC |
263 | #endif |
264 | { } | |
265 | }; | |
8cfc8ddc GT |
266 | |
267 | static int pstore_compress(const void *in, void *out, | |
cb3bee03 | 268 | unsigned int inlen, unsigned int outlen) |
8cfc8ddc | 269 | { |
cb3bee03 GT |
270 | int ret; |
271 | ||
272 | ret = crypto_comp_compress(tfm, in, inlen, out, &outlen); | |
273 | if (ret) { | |
274 | pr_err("crypto_comp_compress failed, ret = %d!\n", ret); | |
275 | return ret; | |
276 | } | |
277 | ||
278 | return outlen; | |
8cfc8ddc GT |
279 | } |
280 | ||
8cfc8ddc GT |
281 | static void allocate_buf_for_compression(void) |
282 | { | |
95047b05 KC |
283 | struct crypto_comp *ctx; |
284 | int size; | |
285 | char *buf; | |
286 | ||
287 | /* Skip if not built-in or compression backend not selected yet. */ | |
e698aaf3 | 288 | if (!IS_ENABLED(CONFIG_PSTORE_COMPRESS) || !zbackend) |
cb3bee03 GT |
289 | return; |
290 | ||
95047b05 KC |
291 | /* Skip if no pstore backend yet or compression init already done. */ |
292 | if (!psinfo || tfm) | |
293 | return; | |
294 | ||
cb3bee03 | 295 | if (!crypto_has_comp(zbackend->name, 0, 0)) { |
95047b05 | 296 | pr_err("Unknown compression: %s\n", zbackend->name); |
cb3bee03 GT |
297 | return; |
298 | } | |
299 | ||
95047b05 KC |
300 | size = zbackend->zbufsize(psinfo->bufsize); |
301 | if (size <= 0) { | |
302 | pr_err("Invalid compression size for %s: %d\n", | |
303 | zbackend->name, size); | |
cb3bee03 | 304 | return; |
95047b05 | 305 | } |
cb3bee03 | 306 | |
95047b05 KC |
307 | buf = kmalloc(size, GFP_KERNEL); |
308 | if (!buf) { | |
309 | pr_err("Failed %d byte compression buffer allocation for: %s\n", | |
310 | size, zbackend->name); | |
cb3bee03 GT |
311 | return; |
312 | } | |
313 | ||
95047b05 KC |
314 | ctx = crypto_alloc_comp(zbackend->name, 0, 0); |
315 | if (IS_ERR_OR_NULL(ctx)) { | |
316 | kfree(buf); | |
317 | pr_err("crypto_alloc_comp('%s') failed: %ld\n", zbackend->name, | |
318 | PTR_ERR(ctx)); | |
cb3bee03 | 319 | return; |
8cfc8ddc | 320 | } |
95047b05 KC |
321 | |
322 | /* A non-NULL big_oops_buf indicates compression is available. */ | |
323 | tfm = ctx; | |
324 | big_oops_buf_sz = size; | |
325 | big_oops_buf = buf; | |
326 | ||
0eed84ff | 327 | pr_info("Using crash dump compression: %s\n", zbackend->name); |
8cfc8ddc GT |
328 | } |
329 | ||
330 | static void free_buf_for_compression(void) | |
331 | { | |
a9fb94a9 | 332 | if (IS_ENABLED(CONFIG_PSTORE_COMPRESS) && tfm) { |
cb3bee03 | 333 | crypto_free_comp(tfm); |
a9fb94a9 PHS |
334 | tfm = NULL; |
335 | } | |
cb3bee03 GT |
336 | kfree(big_oops_buf); |
337 | big_oops_buf = NULL; | |
338 | big_oops_buf_sz = 0; | |
ee1d2674 GT |
339 | } |
340 | ||
b0aad7a9 AB |
341 | /* |
342 | * Called when compression fails, since the printk buffer | |
343 | * would be fetched for compression calling it again when | |
344 | * compression fails would have moved the iterator of | |
345 | * printk buffer which results in fetching old contents. | |
346 | * Copy the recent messages from big_oops_buf to psinfo->buf | |
347 | */ | |
348 | static size_t copy_kmsg_to_buffer(int hsize, size_t len) | |
349 | { | |
350 | size_t total_len; | |
351 | size_t diff; | |
352 | ||
353 | total_len = hsize + len; | |
354 | ||
355 | if (total_len > psinfo->bufsize) { | |
356 | diff = total_len - psinfo->bufsize + hsize; | |
357 | memcpy(psinfo->buf, big_oops_buf, hsize); | |
358 | memcpy(psinfo->buf + hsize, big_oops_buf + diff, | |
359 | psinfo->bufsize - hsize); | |
360 | total_len = psinfo->bufsize; | |
361 | } else | |
362 | memcpy(psinfo->buf, big_oops_buf, total_len); | |
363 | ||
364 | return total_len; | |
365 | } | |
366 | ||
e581ca81 KC |
367 | void pstore_record_init(struct pstore_record *record, |
368 | struct pstore_info *psinfo) | |
369 | { | |
370 | memset(record, 0, sizeof(*record)); | |
371 | ||
372 | record->psi = psinfo; | |
c7f3c595 KC |
373 | |
374 | /* Report zeroed timestamp if called before timekeeping has resumed. */ | |
7aaa822e | 375 | record->time = ns_to_timespec64(ktime_get_real_fast_ns()); |
e581ca81 KC |
376 | } |
377 | ||
ca01d6dd | 378 | /* |
0eed84ff KC |
379 | * callback from kmsg_dump. Save as much as we can (up to kmsg_bytes) from the |
380 | * end of the buffer. | |
ca01d6dd TL |
381 | */ |
382 | static void pstore_dump(struct kmsg_dumper *dumper, | |
e2ae715d | 383 | enum kmsg_dump_reason reason) |
ca01d6dd | 384 | { |
e2ae715d | 385 | unsigned long total = 0; |
381b872c | 386 | const char *why; |
b94fdd07 | 387 | unsigned int part = 1; |
e2ae715d | 388 | int ret; |
ca01d6dd | 389 | |
fb13cb8a | 390 | why = kmsg_dump_reason_str(reason); |
9f6af27f | 391 | |
ea84b580 KC |
392 | if (down_trylock(&psinfo->buf_lock)) { |
393 | /* Failed to acquire lock: give up if we cannot wait. */ | |
394 | if (pstore_cannot_wait(reason)) { | |
395 | pr_err("dump skipped in %s path: may corrupt error record\n", | |
396 | in_nmi() ? "NMI" : why); | |
397 | return; | |
398 | } | |
399 | if (down_interruptible(&psinfo->buf_lock)) { | |
400 | pr_err("could not grab semaphore?!\n"); | |
959217c8 | 401 | return; |
9f244e9c | 402 | } |
98e44fda | 403 | } |
ea84b580 | 404 | |
ca01d6dd TL |
405 | oopscount++; |
406 | while (total < kmsg_bytes) { | |
e2ae715d | 407 | char *dst; |
76cc9580 KC |
408 | size_t dst_size; |
409 | int header_size; | |
b0aad7a9 | 410 | int zipped_len = -1; |
76cc9580 | 411 | size_t dump_size; |
e581ca81 KC |
412 | struct pstore_record record; |
413 | ||
414 | pstore_record_init(&record, psinfo); | |
415 | record.type = PSTORE_TYPE_DMESG; | |
416 | record.count = oopscount; | |
417 | record.reason = reason; | |
418 | record.part = part; | |
419 | record.buf = psinfo->buf; | |
e2ae715d | 420 | |
ea84b580 | 421 | if (big_oops_buf) { |
b0aad7a9 | 422 | dst = big_oops_buf; |
76cc9580 | 423 | dst_size = big_oops_buf_sz; |
235f6d15 NK |
424 | } else { |
425 | dst = psinfo->buf; | |
76cc9580 | 426 | dst_size = psinfo->bufsize; |
235f6d15 NK |
427 | } |
428 | ||
76cc9580 KC |
429 | /* Write dump header. */ |
430 | header_size = snprintf(dst, dst_size, "%s#%d Part%u\n", why, | |
431 | oopscount, part); | |
432 | dst_size -= header_size; | |
ca01d6dd | 433 | |
76cc9580 KC |
434 | /* Write dump contents. */ |
435 | if (!kmsg_dump_get_buffer(dumper, true, dst + header_size, | |
436 | dst_size, &dump_size)) | |
235f6d15 | 437 | break; |
b0aad7a9 | 438 | |
ea84b580 | 439 | if (big_oops_buf) { |
b0aad7a9 | 440 | zipped_len = pstore_compress(dst, psinfo->buf, |
76cc9580 KC |
441 | header_size + dump_size, |
442 | psinfo->bufsize); | |
b0aad7a9 AB |
443 | |
444 | if (zipped_len > 0) { | |
76cc9580 KC |
445 | record.compressed = true; |
446 | record.size = zipped_len; | |
b0aad7a9 | 447 | } else { |
76cc9580 KC |
448 | record.size = copy_kmsg_to_buffer(header_size, |
449 | dump_size); | |
b0aad7a9 AB |
450 | } |
451 | } else { | |
76cc9580 | 452 | record.size = header_size + dump_size; |
b0aad7a9 | 453 | } |
ca01d6dd | 454 | |
76cc9580 | 455 | ret = psinfo->write(&record); |
78c83c82 | 456 | if (ret == 0 && reason == KMSG_DUMP_OOPS) { |
6dda9266 | 457 | pstore_new_entry = 1; |
78c83c82 KC |
458 | pstore_timer_kick(); |
459 | } | |
e2ae715d | 460 | |
76cc9580 | 461 | total += record.size; |
56280682 | 462 | part++; |
ca01d6dd | 463 | } |
ea84b580 KC |
464 | |
465 | up(&psinfo->buf_lock); | |
ca01d6dd TL |
466 | } |
467 | ||
468 | static struct kmsg_dumper pstore_dumper = { | |
469 | .dump = pstore_dump, | |
470 | }; | |
471 | ||
306e5c2a GT |
472 | /* |
473 | * Register with kmsg_dump to save last part of console log on panic. | |
474 | */ | |
18730411 GT |
475 | static void pstore_register_kmsg(void) |
476 | { | |
477 | kmsg_dump_register(&pstore_dumper); | |
478 | } | |
479 | ||
ee1d2674 GT |
480 | static void pstore_unregister_kmsg(void) |
481 | { | |
482 | kmsg_dump_unregister(&pstore_dumper); | |
483 | } | |
484 | ||
f29e5956 AV |
485 | #ifdef CONFIG_PSTORE_CONSOLE |
486 | static void pstore_console_write(struct console *con, const char *s, unsigned c) | |
487 | { | |
b77fa617 | 488 | struct pstore_record record; |
f29e5956 | 489 | |
4c6c4d34 YH |
490 | if (!c) |
491 | return; | |
492 | ||
b77fa617 KC |
493 | pstore_record_init(&record, psinfo); |
494 | record.type = PSTORE_TYPE_CONSOLE; | |
80c9d03c | 495 | |
b77fa617 KC |
496 | record.buf = (char *)s; |
497 | record.size = c; | |
498 | psinfo->write(&record); | |
f29e5956 AV |
499 | } |
500 | ||
501 | static struct console pstore_console = { | |
f29e5956 | 502 | .write = pstore_console_write, |
f29e5956 AV |
503 | .index = -1, |
504 | }; | |
505 | ||
506 | static void pstore_register_console(void) | |
507 | { | |
d195c390 KC |
508 | /* Show which backend is going to get console writes. */ |
509 | strscpy(pstore_console.name, psinfo->name, | |
510 | sizeof(pstore_console.name)); | |
b7753fc7 KC |
511 | /* |
512 | * Always initialize flags here since prior unregister_console() | |
513 | * calls may have changed settings (specifically CON_ENABLED). | |
514 | */ | |
515 | pstore_console.flags = CON_PRINTBUFFER | CON_ENABLED | CON_ANYTIME; | |
f29e5956 AV |
516 | register_console(&pstore_console); |
517 | } | |
ee1d2674 GT |
518 | |
519 | static void pstore_unregister_console(void) | |
520 | { | |
521 | unregister_console(&pstore_console); | |
522 | } | |
f29e5956 AV |
523 | #else |
524 | static void pstore_register_console(void) {} | |
ee1d2674 | 525 | static void pstore_unregister_console(void) {} |
f29e5956 AV |
526 | #endif |
527 | ||
4c9ec219 KC |
528 | static int pstore_write_user_compat(struct pstore_record *record, |
529 | const char __user *buf) | |
5bf6d1b9 | 530 | { |
30800d99 KC |
531 | int ret = 0; |
532 | ||
533 | if (record->buf) | |
534 | return -EINVAL; | |
535 | ||
077090af | 536 | record->buf = memdup_user(buf, record->size); |
dfd6fa39 | 537 | if (IS_ERR(record->buf)) { |
077090af | 538 | ret = PTR_ERR(record->buf); |
30800d99 | 539 | goto out; |
5bf6d1b9 | 540 | } |
30800d99 KC |
541 | |
542 | ret = record->psi->write(record); | |
543 | ||
30800d99 | 544 | kfree(record->buf); |
077090af | 545 | out: |
30800d99 KC |
546 | record->buf = NULL; |
547 | ||
548 | return unlikely(ret < 0) ? ret : record->size; | |
5bf6d1b9 MS |
549 | } |
550 | ||
ca01d6dd TL |
551 | /* |
552 | * platform specific persistent storage driver registers with | |
553 | * us here. If pstore is already mounted, call the platform | |
554 | * read function right away to populate the file system. If not | |
555 | * then the pstore mount code will call us later to fill out | |
556 | * the file system. | |
ca01d6dd TL |
557 | */ |
558 | int pstore_register(struct pstore_info *psi) | |
559 | { | |
0d7cd09a KC |
560 | if (backend && strcmp(backend, psi->name)) { |
561 | pr_warn("ignoring unexpected backend '%s'\n", psi->name); | |
8e48b1a8 | 562 | return -EPERM; |
0d7cd09a | 563 | } |
8e48b1a8 | 564 | |
4c9ec219 KC |
565 | /* Sanity check flags. */ |
566 | if (!psi->flags) { | |
567 | pr_warn("backend '%s' must support at least one frontend\n", | |
568 | psi->name); | |
569 | return -EINVAL; | |
570 | } | |
571 | ||
572 | /* Check for required functions. */ | |
573 | if (!psi->read || !psi->write) { | |
574 | pr_warn("backend '%s' must implement read() and write()\n", | |
575 | psi->name); | |
576 | return -EINVAL; | |
577 | } | |
578 | ||
cab12fd0 | 579 | mutex_lock(&psinfo_lock); |
ca01d6dd | 580 | if (psinfo) { |
0d7cd09a KC |
581 | pr_warn("backend '%s' already loaded: ignoring '%s'\n", |
582 | psinfo->name, psi->name); | |
cab12fd0 | 583 | mutex_unlock(&psinfo_lock); |
ca01d6dd TL |
584 | return -EBUSY; |
585 | } | |
dee28e72 | 586 | |
4c9ec219 KC |
587 | if (!psi->write_user) |
588 | psi->write_user = pstore_write_user_compat; | |
ca01d6dd | 589 | psinfo = psi; |
f6f82851 | 590 | mutex_init(&psinfo->read_mutex); |
ea84b580 | 591 | sema_init(&psinfo->buf_lock, 1); |
ca01d6dd | 592 | |
8880fa32 KC |
593 | if (psi->flags & PSTORE_FLAGS_DMESG) |
594 | allocate_buf_for_compression(); | |
b0aad7a9 | 595 | |
27e5041a | 596 | pstore_get_records(0); |
ca01d6dd | 597 | |
c950fd6f NK |
598 | if (psi->flags & PSTORE_FLAGS_DMESG) |
599 | pstore_register_kmsg(); | |
600 | if (psi->flags & PSTORE_FLAGS_CONSOLE) | |
df36ac1b | 601 | pstore_register_console(); |
c950fd6f | 602 | if (psi->flags & PSTORE_FLAGS_FTRACE) |
df36ac1b | 603 | pstore_register_ftrace(); |
c950fd6f | 604 | if (psi->flags & PSTORE_FLAGS_PMSG) |
9d5438f4 | 605 | pstore_register_pmsg(); |
ca01d6dd | 606 | |
6330d553 | 607 | /* Start watching for new records, if desired. */ |
78c83c82 | 608 | pstore_timer_kick(); |
6dda9266 | 609 | |
42222c2a WL |
610 | /* |
611 | * Update the module parameter backend, so it is visible | |
612 | * through /sys/module/pstore/parameters/backend | |
613 | */ | |
563ca40d | 614 | backend = kstrdup(psi->name, GFP_KERNEL); |
42222c2a | 615 | |
ef748853 | 616 | pr_info("Registered %s as persistent store backend\n", psi->name); |
8e48b1a8 | 617 | |
6248a066 | 618 | mutex_unlock(&psinfo_lock); |
ca01d6dd TL |
619 | return 0; |
620 | } | |
621 | EXPORT_SYMBOL_GPL(pstore_register); | |
622 | ||
ee1d2674 GT |
623 | void pstore_unregister(struct pstore_info *psi) |
624 | { | |
6248a066 KC |
625 | /* It's okay to unregister nothing. */ |
626 | if (!psi) | |
627 | return; | |
628 | ||
629 | mutex_lock(&psinfo_lock); | |
630 | ||
631 | /* Only one backend can be registered at a time. */ | |
632 | if (WARN_ON(psi != psinfo)) { | |
633 | mutex_unlock(&psinfo_lock); | |
634 | return; | |
635 | } | |
636 | ||
78c83c82 | 637 | /* Unregister all callbacks. */ |
c950fd6f | 638 | if (psi->flags & PSTORE_FLAGS_PMSG) |
a1db8060 | 639 | pstore_unregister_pmsg(); |
c950fd6f | 640 | if (psi->flags & PSTORE_FLAGS_FTRACE) |
a1db8060 | 641 | pstore_unregister_ftrace(); |
c950fd6f | 642 | if (psi->flags & PSTORE_FLAGS_CONSOLE) |
a1db8060 | 643 | pstore_unregister_console(); |
c950fd6f NK |
644 | if (psi->flags & PSTORE_FLAGS_DMESG) |
645 | pstore_unregister_kmsg(); | |
ee1d2674 | 646 | |
78c83c82 KC |
647 | /* Stop timer and make sure all work has finished. */ |
648 | del_timer_sync(&pstore_timer); | |
649 | flush_work(&pstore_work); | |
650 | ||
609e28bb KC |
651 | /* Remove all backend records from filesystem tree. */ |
652 | pstore_put_backend_records(psi); | |
653 | ||
ee1d2674 GT |
654 | free_buf_for_compression(); |
655 | ||
656 | psinfo = NULL; | |
563ca40d | 657 | kfree(backend); |
ee1d2674 | 658 | backend = NULL; |
6248a066 | 659 | mutex_unlock(&psinfo_lock); |
ee1d2674 GT |
660 | } |
661 | EXPORT_SYMBOL_GPL(pstore_unregister); | |
662 | ||
634f8f51 KC |
663 | static void decompress_record(struct pstore_record *record) |
664 | { | |
bdabc8e7 | 665 | int ret; |
634f8f51 | 666 | int unzipped_len; |
bdabc8e7 | 667 | char *unzipped, *workspace; |
634f8f51 | 668 | |
4a16d1cb AK |
669 | if (!record->compressed) |
670 | return; | |
671 | ||
634f8f51 | 672 | /* Only PSTORE_TYPE_DMESG support compression. */ |
4a16d1cb | 673 | if (record->type != PSTORE_TYPE_DMESG) { |
634f8f51 KC |
674 | pr_warn("ignored compressed record type %d\n", record->type); |
675 | return; | |
676 | } | |
677 | ||
bdabc8e7 | 678 | /* Missing compression buffer means compression was not initialized. */ |
634f8f51 | 679 | if (!big_oops_buf) { |
bdabc8e7 | 680 | pr_warn("no decompression method initialized!\n"); |
634f8f51 KC |
681 | return; |
682 | } | |
683 | ||
bdabc8e7 KC |
684 | /* Allocate enough space to hold max decompression and ECC. */ |
685 | unzipped_len = big_oops_buf_sz; | |
686 | workspace = kmalloc(unzipped_len + record->ecc_notice_size, | |
687 | GFP_KERNEL); | |
688 | if (!workspace) | |
7e8cc8dc | 689 | return; |
7e8cc8dc | 690 | |
bdabc8e7 KC |
691 | /* After decompression "unzipped_len" is almost certainly smaller. */ |
692 | ret = crypto_comp_decompress(tfm, record->buf, record->size, | |
693 | workspace, &unzipped_len); | |
694 | if (ret) { | |
695 | pr_err("crypto_comp_decompress failed, ret = %d!\n", ret); | |
696 | kfree(workspace); | |
7e8cc8dc KC |
697 | return; |
698 | } | |
7e8cc8dc KC |
699 | |
700 | /* Append ECC notice to decompressed buffer. */ | |
bdabc8e7 | 701 | memcpy(workspace + unzipped_len, record->buf + record->size, |
7e8cc8dc KC |
702 | record->ecc_notice_size); |
703 | ||
bdabc8e7 KC |
704 | /* Copy decompressed contents into an minimum-sized allocation. */ |
705 | unzipped = kmemdup(workspace, unzipped_len + record->ecc_notice_size, | |
706 | GFP_KERNEL); | |
707 | kfree(workspace); | |
708 | if (!unzipped) | |
709 | return; | |
710 | ||
711 | /* Swap out compressed contents with decompressed contents. */ | |
7e8cc8dc | 712 | kfree(record->buf); |
bdabc8e7 | 713 | record->buf = unzipped; |
7e8cc8dc KC |
714 | record->size = unzipped_len; |
715 | record->compressed = false; | |
634f8f51 KC |
716 | } |
717 | ||
ca01d6dd | 718 | /* |
3a7d2fd1 | 719 | * Read all the records from one persistent store backend. Create |
6dda9266 LT |
720 | * files in our filesystem. Don't warn about -EEXIST errors |
721 | * when we are re-scanning the backing store looking to add new | |
722 | * error records. | |
ca01d6dd | 723 | */ |
3a7d2fd1 KC |
724 | void pstore_get_backend_records(struct pstore_info *psi, |
725 | struct dentry *root, int quiet) | |
ca01d6dd | 726 | { |
2a2b0acf | 727 | int failed = 0; |
656de42e | 728 | unsigned int stop_loop = 65536; |
ca01d6dd | 729 | |
3a7d2fd1 | 730 | if (!psi || !root) |
ca01d6dd TL |
731 | return; |
732 | ||
f6f82851 | 733 | mutex_lock(&psi->read_mutex); |
2174f6df | 734 | if (psi->open && psi->open(psi)) |
06cf91b4 CG |
735 | goto out; |
736 | ||
1dfff7dd KC |
737 | /* |
738 | * Backend callback read() allocates record.buf. decompress_record() | |
739 | * may reallocate record.buf. On success, pstore_mkfile() will keep | |
740 | * the record.buf, so free it only on failure. | |
741 | */ | |
656de42e | 742 | for (; stop_loop; stop_loop--) { |
2a2b0acf KC |
743 | struct pstore_record *record; |
744 | int rc; | |
745 | ||
746 | record = kzalloc(sizeof(*record), GFP_KERNEL); | |
747 | if (!record) { | |
748 | pr_err("out of memory creating record\n"); | |
749 | break; | |
750 | } | |
e581ca81 | 751 | pstore_record_init(record, psi); |
2a2b0acf KC |
752 | |
753 | record->size = psi->read(record); | |
754 | ||
755 | /* No more records left in backend? */ | |
f6525b96 DA |
756 | if (record->size <= 0) { |
757 | kfree(record); | |
2a2b0acf | 758 | break; |
f6525b96 | 759 | } |
2a2b0acf KC |
760 | |
761 | decompress_record(record); | |
3a7d2fd1 | 762 | rc = pstore_mkfile(root, record); |
1dfff7dd | 763 | if (rc) { |
83f70f07 | 764 | /* pstore_mkfile() did not take record, so free it. */ |
2a2b0acf | 765 | kfree(record->buf); |
83f70f07 | 766 | kfree(record); |
1dfff7dd KC |
767 | if (rc != -EEXIST || !quiet) |
768 | failed++; | |
769 | } | |
ca01d6dd | 770 | } |
2174f6df KC |
771 | if (psi->close) |
772 | psi->close(psi); | |
06cf91b4 | 773 | out: |
f6f82851 | 774 | mutex_unlock(&psi->read_mutex); |
ca01d6dd TL |
775 | |
776 | if (failed) | |
656de42e | 777 | pr_warn("failed to create %d record(s) from '%s'\n", |
ef748853 | 778 | failed, psi->name); |
656de42e KC |
779 | if (!stop_loop) |
780 | pr_err("looping? Too many records seen from '%s'\n", | |
781 | psi->name); | |
ca01d6dd TL |
782 | } |
783 | ||
6dda9266 LT |
784 | static void pstore_dowork(struct work_struct *work) |
785 | { | |
786 | pstore_get_records(1); | |
787 | } | |
788 | ||
24ed960a | 789 | static void pstore_timefunc(struct timer_list *unused) |
6dda9266 LT |
790 | { |
791 | if (pstore_new_entry) { | |
792 | pstore_new_entry = 0; | |
793 | schedule_work(&pstore_work); | |
794 | } | |
795 | ||
78c83c82 | 796 | pstore_timer_kick(); |
6dda9266 LT |
797 | } |
798 | ||
8d82cee2 | 799 | static void __init pstore_choose_compression(void) |
fe1d4758 KC |
800 | { |
801 | const struct pstore_zbackend *step; | |
802 | ||
803 | if (!compress) | |
804 | return; | |
805 | ||
806 | for (step = zbackends; step->name; step++) { | |
807 | if (!strcmp(compress, step->name)) { | |
808 | zbackend = step; | |
fe1d4758 KC |
809 | return; |
810 | } | |
811 | } | |
812 | } | |
813 | ||
cb095afd KC |
814 | static int __init pstore_init(void) |
815 | { | |
816 | int ret; | |
817 | ||
818 | pstore_choose_compression(); | |
819 | ||
41603165 JFG |
820 | /* |
821 | * Check if any pstore backends registered earlier but did not | |
822 | * initialize compression because crypto was not ready. If so, | |
823 | * initialize compression now. | |
824 | */ | |
95047b05 | 825 | allocate_buf_for_compression(); |
41603165 | 826 | |
cb095afd KC |
827 | ret = pstore_init_fs(); |
828 | if (ret) | |
8a57d6d4 | 829 | free_buf_for_compression(); |
cb095afd | 830 | |
8a57d6d4 | 831 | return ret; |
cb095afd | 832 | } |
41603165 | 833 | late_initcall(pstore_init); |
cb095afd KC |
834 | |
835 | static void __exit pstore_exit(void) | |
836 | { | |
837 | pstore_exit_fs(); | |
838 | } | |
839 | module_exit(pstore_exit) | |
840 | ||
cb095afd KC |
841 | MODULE_AUTHOR("Tony Luck <tony.luck@intel.com>"); |
842 | MODULE_LICENSE("GPL"); |