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 AV |
46 | "(default is -1, which means runtime updates are disabled; " |
47 | "enabling this option is not safe, it may lead to further " | |
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 TL |
71 | /* |
72 | * pstore_lock just protects "psinfo" during | |
73 | * calls to pstore_register() | |
74 | */ | |
75 | static DEFINE_SPINLOCK(pstore_lock); | |
060287b8 | 76 | struct pstore_info *psinfo; |
ca01d6dd | 77 | |
dee28e72 | 78 | static char *backend; |
fe1d4758 KC |
79 | static char *compress = |
80 | #ifdef CONFIG_PSTORE_COMPRESS_DEFAULT | |
81 | CONFIG_PSTORE_COMPRESS_DEFAULT; | |
82 | #else | |
83 | NULL; | |
84 | #endif | |
dee28e72 | 85 | |
b0aad7a9 | 86 | /* Compression parameters */ |
cb3bee03 | 87 | static struct crypto_comp *tfm; |
8cfc8ddc GT |
88 | |
89 | struct pstore_zbackend { | |
cb3bee03 | 90 | int (*zbufsize)(size_t size); |
8cfc8ddc GT |
91 | const char *name; |
92 | }; | |
b0aad7a9 AB |
93 | |
94 | static char *big_oops_buf; | |
95 | static size_t big_oops_buf_sz; | |
96 | ||
366f7e7a | 97 | /* How much of the console log to snapshot */ |
349d7438 | 98 | unsigned long kmsg_bytes = PSTORE_DEFAULT_KMSG_BYTES; |
ca01d6dd | 99 | |
366f7e7a | 100 | void pstore_set_kmsg_bytes(int bytes) |
ca01d6dd | 101 | { |
366f7e7a | 102 | kmsg_bytes = bytes; |
ca01d6dd TL |
103 | } |
104 | ||
ca01d6dd TL |
105 | /* Tag each group of saved records with a sequence number */ |
106 | static int oopscount; | |
107 | ||
f0f23e54 JFG |
108 | const char *pstore_type_to_name(enum pstore_type_id type) |
109 | { | |
110 | BUILD_BUG_ON(ARRAY_SIZE(pstore_type_names) != PSTORE_TYPE_MAX); | |
111 | ||
112 | if (WARN_ON_ONCE(type >= PSTORE_TYPE_MAX)) | |
113 | return "unknown"; | |
114 | ||
115 | return pstore_type_names[type]; | |
116 | } | |
117 | EXPORT_SYMBOL_GPL(pstore_type_to_name); | |
118 | ||
119 | enum pstore_type_id pstore_name_to_type(const char *name) | |
120 | { | |
121 | int i; | |
122 | ||
123 | for (i = 0; i < PSTORE_TYPE_MAX; i++) { | |
124 | if (!strcmp(pstore_type_names[i], name)) | |
125 | return i; | |
126 | } | |
127 | ||
128 | return PSTORE_TYPE_MAX; | |
129 | } | |
130 | EXPORT_SYMBOL_GPL(pstore_name_to_type); | |
131 | ||
381b872c SA |
132 | static const char *get_reason_str(enum kmsg_dump_reason reason) |
133 | { | |
134 | switch (reason) { | |
135 | case KMSG_DUMP_PANIC: | |
136 | return "Panic"; | |
137 | case KMSG_DUMP_OOPS: | |
138 | return "Oops"; | |
139 | case KMSG_DUMP_EMERG: | |
140 | return "Emergency"; | |
141 | case KMSG_DUMP_RESTART: | |
142 | return "Restart"; | |
143 | case KMSG_DUMP_HALT: | |
144 | return "Halt"; | |
145 | case KMSG_DUMP_POWEROFF: | |
146 | return "Poweroff"; | |
147 | default: | |
148 | return "Unknown"; | |
149 | } | |
150 | } | |
9f6af27f | 151 | |
ea84b580 KC |
152 | /* |
153 | * Should pstore_dump() wait for a concurrent pstore_dump()? If | |
154 | * not, the current pstore_dump() will report a failure to dump | |
155 | * and return. | |
156 | */ | |
157 | static bool pstore_cannot_wait(enum kmsg_dump_reason reason) | |
9f244e9c | 158 | { |
ea84b580 | 159 | /* In NMI path, pstore shouldn't block regardless of reason. */ |
9f244e9c SA |
160 | if (in_nmi()) |
161 | return true; | |
162 | ||
163 | switch (reason) { | |
164 | /* In panic case, other cpus are stopped by smp_send_stop(). */ | |
165 | case KMSG_DUMP_PANIC: | |
ea84b580 | 166 | /* Emergency restart shouldn't be blocked. */ |
9f244e9c SA |
167 | case KMSG_DUMP_EMERG: |
168 | return true; | |
169 | default: | |
170 | return false; | |
171 | } | |
172 | } | |
9f244e9c | 173 | |
58eb5b67 | 174 | #if IS_ENABLED(CONFIG_PSTORE_DEFLATE_COMPRESS) |
cb3bee03 | 175 | static int zbufsize_deflate(size_t size) |
adb42f5e | 176 | { |
7de8fe2f AB |
177 | size_t cmpr; |
178 | ||
cb3bee03 | 179 | switch (size) { |
7de8fe2f AB |
180 | /* buffer range for efivars */ |
181 | case 1000 ... 2000: | |
182 | cmpr = 56; | |
183 | break; | |
184 | case 2001 ... 3000: | |
185 | cmpr = 54; | |
186 | break; | |
187 | case 3001 ... 3999: | |
188 | cmpr = 52; | |
189 | break; | |
190 | /* buffer range for nvram, erst */ | |
191 | case 4000 ... 10000: | |
192 | cmpr = 45; | |
193 | break; | |
194 | default: | |
195 | cmpr = 60; | |
196 | break; | |
197 | } | |
b0aad7a9 | 198 | |
cb3bee03 | 199 | return (size * 100) / cmpr; |
8cfc8ddc | 200 | } |
8cfc8ddc GT |
201 | #endif |
202 | ||
58eb5b67 | 203 | #if IS_ENABLED(CONFIG_PSTORE_LZO_COMPRESS) |
cb3bee03 | 204 | static int zbufsize_lzo(size_t size) |
8cfc8ddc | 205 | { |
cb3bee03 | 206 | return lzo1x_worst_compress(size); |
8cfc8ddc | 207 | } |
8cfc8ddc GT |
208 | #endif |
209 | ||
58eb5b67 | 210 | #if IS_ENABLED(CONFIG_PSTORE_LZ4_COMPRESS) || IS_ENABLED(CONFIG_PSTORE_LZ4HC_COMPRESS) |
cb3bee03 | 211 | static int zbufsize_lz4(size_t size) |
8cfc8ddc | 212 | { |
cb3bee03 | 213 | return LZ4_compressBound(size); |
8cfc8ddc | 214 | } |
239b7161 GT |
215 | #endif |
216 | ||
58eb5b67 | 217 | #if IS_ENABLED(CONFIG_PSTORE_842_COMPRESS) |
cb3bee03 | 218 | static int zbufsize_842(size_t size) |
239b7161 | 219 | { |
55597406 | 220 | return size; |
239b7161 | 221 | } |
8cfc8ddc GT |
222 | #endif |
223 | ||
1021bcf4 GT |
224 | #if IS_ENABLED(CONFIG_PSTORE_ZSTD_COMPRESS) |
225 | static int zbufsize_zstd(size_t size) | |
226 | { | |
227 | return ZSTD_compressBound(size); | |
228 | } | |
229 | #endif | |
230 | ||
fe1d4758 KC |
231 | static const struct pstore_zbackend *zbackend __ro_after_init; |
232 | ||
233 | static const struct pstore_zbackend zbackends[] = { | |
58eb5b67 | 234 | #if IS_ENABLED(CONFIG_PSTORE_DEFLATE_COMPRESS) |
fe1d4758 | 235 | { |
cb3bee03 GT |
236 | .zbufsize = zbufsize_deflate, |
237 | .name = "deflate", | |
fe1d4758 KC |
238 | }, |
239 | #endif | |
58eb5b67 | 240 | #if IS_ENABLED(CONFIG_PSTORE_LZO_COMPRESS) |
fe1d4758 | 241 | { |
cb3bee03 | 242 | .zbufsize = zbufsize_lzo, |
fe1d4758 KC |
243 | .name = "lzo", |
244 | }, | |
245 | #endif | |
58eb5b67 | 246 | #if IS_ENABLED(CONFIG_PSTORE_LZ4_COMPRESS) |
fe1d4758 | 247 | { |
cb3bee03 | 248 | .zbufsize = zbufsize_lz4, |
fe1d4758 KC |
249 | .name = "lz4", |
250 | }, | |
251 | #endif | |
58eb5b67 | 252 | #if IS_ENABLED(CONFIG_PSTORE_LZ4HC_COMPRESS) |
fe1d4758 | 253 | { |
cb3bee03 | 254 | .zbufsize = zbufsize_lz4, |
fe1d4758 KC |
255 | .name = "lz4hc", |
256 | }, | |
8cfc8ddc | 257 | #endif |
58eb5b67 | 258 | #if IS_ENABLED(CONFIG_PSTORE_842_COMPRESS) |
fe1d4758 | 259 | { |
cb3bee03 | 260 | .zbufsize = zbufsize_842, |
fe1d4758 KC |
261 | .name = "842", |
262 | }, | |
1021bcf4 GT |
263 | #endif |
264 | #if IS_ENABLED(CONFIG_PSTORE_ZSTD_COMPRESS) | |
265 | { | |
266 | .zbufsize = zbufsize_zstd, | |
267 | .name = "zstd", | |
268 | }, | |
fe1d4758 KC |
269 | #endif |
270 | { } | |
271 | }; | |
8cfc8ddc GT |
272 | |
273 | static int pstore_compress(const void *in, void *out, | |
cb3bee03 | 274 | unsigned int inlen, unsigned int outlen) |
8cfc8ddc | 275 | { |
cb3bee03 GT |
276 | int ret; |
277 | ||
278 | ret = crypto_comp_compress(tfm, in, inlen, out, &outlen); | |
279 | if (ret) { | |
280 | pr_err("crypto_comp_compress failed, ret = %d!\n", ret); | |
281 | return ret; | |
282 | } | |
283 | ||
284 | return outlen; | |
8cfc8ddc GT |
285 | } |
286 | ||
8cfc8ddc GT |
287 | static void allocate_buf_for_compression(void) |
288 | { | |
95047b05 KC |
289 | struct crypto_comp *ctx; |
290 | int size; | |
291 | char *buf; | |
292 | ||
293 | /* Skip if not built-in or compression backend not selected yet. */ | |
e698aaf3 | 294 | if (!IS_ENABLED(CONFIG_PSTORE_COMPRESS) || !zbackend) |
cb3bee03 GT |
295 | return; |
296 | ||
95047b05 KC |
297 | /* Skip if no pstore backend yet or compression init already done. */ |
298 | if (!psinfo || tfm) | |
299 | return; | |
300 | ||
cb3bee03 | 301 | if (!crypto_has_comp(zbackend->name, 0, 0)) { |
95047b05 | 302 | pr_err("Unknown compression: %s\n", zbackend->name); |
cb3bee03 GT |
303 | return; |
304 | } | |
305 | ||
95047b05 KC |
306 | size = zbackend->zbufsize(psinfo->bufsize); |
307 | if (size <= 0) { | |
308 | pr_err("Invalid compression size for %s: %d\n", | |
309 | zbackend->name, size); | |
cb3bee03 | 310 | return; |
95047b05 | 311 | } |
cb3bee03 | 312 | |
95047b05 KC |
313 | buf = kmalloc(size, GFP_KERNEL); |
314 | if (!buf) { | |
315 | pr_err("Failed %d byte compression buffer allocation for: %s\n", | |
316 | size, zbackend->name); | |
cb3bee03 GT |
317 | return; |
318 | } | |
319 | ||
95047b05 KC |
320 | ctx = crypto_alloc_comp(zbackend->name, 0, 0); |
321 | if (IS_ERR_OR_NULL(ctx)) { | |
322 | kfree(buf); | |
323 | pr_err("crypto_alloc_comp('%s') failed: %ld\n", zbackend->name, | |
324 | PTR_ERR(ctx)); | |
cb3bee03 | 325 | return; |
8cfc8ddc | 326 | } |
95047b05 KC |
327 | |
328 | /* A non-NULL big_oops_buf indicates compression is available. */ | |
329 | tfm = ctx; | |
330 | big_oops_buf_sz = size; | |
331 | big_oops_buf = buf; | |
332 | ||
0eed84ff | 333 | pr_info("Using crash dump compression: %s\n", zbackend->name); |
8cfc8ddc GT |
334 | } |
335 | ||
336 | static void free_buf_for_compression(void) | |
337 | { | |
a9fb94a9 | 338 | if (IS_ENABLED(CONFIG_PSTORE_COMPRESS) && tfm) { |
cb3bee03 | 339 | crypto_free_comp(tfm); |
a9fb94a9 PHS |
340 | tfm = NULL; |
341 | } | |
cb3bee03 GT |
342 | kfree(big_oops_buf); |
343 | big_oops_buf = NULL; | |
344 | big_oops_buf_sz = 0; | |
ee1d2674 GT |
345 | } |
346 | ||
b0aad7a9 AB |
347 | /* |
348 | * Called when compression fails, since the printk buffer | |
349 | * would be fetched for compression calling it again when | |
350 | * compression fails would have moved the iterator of | |
351 | * printk buffer which results in fetching old contents. | |
352 | * Copy the recent messages from big_oops_buf to psinfo->buf | |
353 | */ | |
354 | static size_t copy_kmsg_to_buffer(int hsize, size_t len) | |
355 | { | |
356 | size_t total_len; | |
357 | size_t diff; | |
358 | ||
359 | total_len = hsize + len; | |
360 | ||
361 | if (total_len > psinfo->bufsize) { | |
362 | diff = total_len - psinfo->bufsize + hsize; | |
363 | memcpy(psinfo->buf, big_oops_buf, hsize); | |
364 | memcpy(psinfo->buf + hsize, big_oops_buf + diff, | |
365 | psinfo->bufsize - hsize); | |
366 | total_len = psinfo->bufsize; | |
367 | } else | |
368 | memcpy(psinfo->buf, big_oops_buf, total_len); | |
369 | ||
370 | return total_len; | |
371 | } | |
372 | ||
e581ca81 KC |
373 | void pstore_record_init(struct pstore_record *record, |
374 | struct pstore_info *psinfo) | |
375 | { | |
376 | memset(record, 0, sizeof(*record)); | |
377 | ||
378 | record->psi = psinfo; | |
c7f3c595 KC |
379 | |
380 | /* Report zeroed timestamp if called before timekeeping has resumed. */ | |
7aaa822e | 381 | record->time = ns_to_timespec64(ktime_get_real_fast_ns()); |
e581ca81 KC |
382 | } |
383 | ||
ca01d6dd | 384 | /* |
0eed84ff KC |
385 | * callback from kmsg_dump. Save as much as we can (up to kmsg_bytes) from the |
386 | * end of the buffer. | |
ca01d6dd TL |
387 | */ |
388 | static void pstore_dump(struct kmsg_dumper *dumper, | |
e2ae715d | 389 | enum kmsg_dump_reason reason) |
ca01d6dd | 390 | { |
e2ae715d | 391 | unsigned long total = 0; |
381b872c | 392 | const char *why; |
b94fdd07 | 393 | unsigned int part = 1; |
e2ae715d | 394 | int ret; |
ca01d6dd | 395 | |
381b872c | 396 | why = get_reason_str(reason); |
9f6af27f | 397 | |
ea84b580 KC |
398 | if (down_trylock(&psinfo->buf_lock)) { |
399 | /* Failed to acquire lock: give up if we cannot wait. */ | |
400 | if (pstore_cannot_wait(reason)) { | |
401 | pr_err("dump skipped in %s path: may corrupt error record\n", | |
402 | in_nmi() ? "NMI" : why); | |
403 | return; | |
404 | } | |
405 | if (down_interruptible(&psinfo->buf_lock)) { | |
406 | pr_err("could not grab semaphore?!\n"); | |
959217c8 | 407 | return; |
9f244e9c | 408 | } |
98e44fda | 409 | } |
ea84b580 | 410 | |
ca01d6dd TL |
411 | oopscount++; |
412 | while (total < kmsg_bytes) { | |
e2ae715d | 413 | char *dst; |
76cc9580 KC |
414 | size_t dst_size; |
415 | int header_size; | |
b0aad7a9 | 416 | int zipped_len = -1; |
76cc9580 | 417 | size_t dump_size; |
e581ca81 KC |
418 | struct pstore_record record; |
419 | ||
420 | pstore_record_init(&record, psinfo); | |
421 | record.type = PSTORE_TYPE_DMESG; | |
422 | record.count = oopscount; | |
423 | record.reason = reason; | |
424 | record.part = part; | |
425 | record.buf = psinfo->buf; | |
e2ae715d | 426 | |
ea84b580 | 427 | if (big_oops_buf) { |
b0aad7a9 | 428 | dst = big_oops_buf; |
76cc9580 | 429 | dst_size = big_oops_buf_sz; |
235f6d15 NK |
430 | } else { |
431 | dst = psinfo->buf; | |
76cc9580 | 432 | dst_size = psinfo->bufsize; |
235f6d15 NK |
433 | } |
434 | ||
76cc9580 KC |
435 | /* Write dump header. */ |
436 | header_size = snprintf(dst, dst_size, "%s#%d Part%u\n", why, | |
437 | oopscount, part); | |
438 | dst_size -= header_size; | |
ca01d6dd | 439 | |
76cc9580 KC |
440 | /* Write dump contents. */ |
441 | if (!kmsg_dump_get_buffer(dumper, true, dst + header_size, | |
442 | dst_size, &dump_size)) | |
235f6d15 | 443 | break; |
b0aad7a9 | 444 | |
ea84b580 | 445 | if (big_oops_buf) { |
b0aad7a9 | 446 | zipped_len = pstore_compress(dst, psinfo->buf, |
76cc9580 KC |
447 | header_size + dump_size, |
448 | psinfo->bufsize); | |
b0aad7a9 AB |
449 | |
450 | if (zipped_len > 0) { | |
76cc9580 KC |
451 | record.compressed = true; |
452 | record.size = zipped_len; | |
b0aad7a9 | 453 | } else { |
76cc9580 KC |
454 | record.size = copy_kmsg_to_buffer(header_size, |
455 | dump_size); | |
b0aad7a9 AB |
456 | } |
457 | } else { | |
76cc9580 | 458 | record.size = header_size + dump_size; |
b0aad7a9 | 459 | } |
ca01d6dd | 460 | |
76cc9580 | 461 | ret = psinfo->write(&record); |
b238b8fa | 462 | if (ret == 0 && reason == KMSG_DUMP_OOPS && pstore_is_mounted()) |
6dda9266 | 463 | pstore_new_entry = 1; |
e2ae715d | 464 | |
76cc9580 | 465 | total += record.size; |
56280682 | 466 | part++; |
ca01d6dd | 467 | } |
ea84b580 KC |
468 | |
469 | up(&psinfo->buf_lock); | |
ca01d6dd TL |
470 | } |
471 | ||
472 | static struct kmsg_dumper pstore_dumper = { | |
473 | .dump = pstore_dump, | |
474 | }; | |
475 | ||
306e5c2a GT |
476 | /* |
477 | * Register with kmsg_dump to save last part of console log on panic. | |
478 | */ | |
18730411 GT |
479 | static void pstore_register_kmsg(void) |
480 | { | |
481 | kmsg_dump_register(&pstore_dumper); | |
482 | } | |
483 | ||
ee1d2674 GT |
484 | static void pstore_unregister_kmsg(void) |
485 | { | |
486 | kmsg_dump_unregister(&pstore_dumper); | |
487 | } | |
488 | ||
f29e5956 AV |
489 | #ifdef CONFIG_PSTORE_CONSOLE |
490 | static void pstore_console_write(struct console *con, const char *s, unsigned c) | |
491 | { | |
b77fa617 | 492 | struct pstore_record record; |
f29e5956 | 493 | |
4c6c4d34 YH |
494 | if (!c) |
495 | return; | |
496 | ||
b77fa617 KC |
497 | pstore_record_init(&record, psinfo); |
498 | record.type = PSTORE_TYPE_CONSOLE; | |
80c9d03c | 499 | |
b77fa617 KC |
500 | record.buf = (char *)s; |
501 | record.size = c; | |
502 | psinfo->write(&record); | |
f29e5956 AV |
503 | } |
504 | ||
505 | static struct console pstore_console = { | |
506 | .name = "pstore", | |
507 | .write = pstore_console_write, | |
508 | .flags = CON_PRINTBUFFER | CON_ENABLED | CON_ANYTIME, | |
509 | .index = -1, | |
510 | }; | |
511 | ||
512 | static void pstore_register_console(void) | |
513 | { | |
514 | register_console(&pstore_console); | |
515 | } | |
ee1d2674 GT |
516 | |
517 | static void pstore_unregister_console(void) | |
518 | { | |
519 | unregister_console(&pstore_console); | |
520 | } | |
f29e5956 AV |
521 | #else |
522 | static void pstore_register_console(void) {} | |
ee1d2674 | 523 | static void pstore_unregister_console(void) {} |
f29e5956 AV |
524 | #endif |
525 | ||
4c9ec219 KC |
526 | static int pstore_write_user_compat(struct pstore_record *record, |
527 | const char __user *buf) | |
5bf6d1b9 | 528 | { |
30800d99 KC |
529 | int ret = 0; |
530 | ||
531 | if (record->buf) | |
532 | return -EINVAL; | |
533 | ||
077090af | 534 | record->buf = memdup_user(buf, record->size); |
dfd6fa39 | 535 | if (IS_ERR(record->buf)) { |
077090af | 536 | ret = PTR_ERR(record->buf); |
30800d99 | 537 | goto out; |
5bf6d1b9 | 538 | } |
30800d99 KC |
539 | |
540 | ret = record->psi->write(record); | |
541 | ||
30800d99 | 542 | kfree(record->buf); |
077090af | 543 | out: |
30800d99 KC |
544 | record->buf = NULL; |
545 | ||
546 | return unlikely(ret < 0) ? ret : record->size; | |
5bf6d1b9 MS |
547 | } |
548 | ||
ca01d6dd TL |
549 | /* |
550 | * platform specific persistent storage driver registers with | |
551 | * us here. If pstore is already mounted, call the platform | |
552 | * read function right away to populate the file system. If not | |
553 | * then the pstore mount code will call us later to fill out | |
554 | * the file system. | |
ca01d6dd TL |
555 | */ |
556 | int pstore_register(struct pstore_info *psi) | |
557 | { | |
558 | struct module *owner = psi->owner; | |
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 | ||
ca01d6dd TL |
579 | spin_lock(&pstore_lock); |
580 | if (psinfo) { | |
0d7cd09a KC |
581 | pr_warn("backend '%s' already loaded: ignoring '%s'\n", |
582 | psinfo->name, psi->name); | |
ca01d6dd TL |
583 | spin_unlock(&pstore_lock); |
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 TL |
592 | spin_unlock(&pstore_lock); |
593 | ||
594 | if (owner && !try_module_get(owner)) { | |
595 | psinfo = NULL; | |
596 | return -EINVAL; | |
597 | } | |
598 | ||
8880fa32 KC |
599 | if (psi->flags & PSTORE_FLAGS_DMESG) |
600 | allocate_buf_for_compression(); | |
b0aad7a9 | 601 | |
ca01d6dd | 602 | if (pstore_is_mounted()) |
6dda9266 | 603 | pstore_get_records(0); |
ca01d6dd | 604 | |
c950fd6f NK |
605 | if (psi->flags & PSTORE_FLAGS_DMESG) |
606 | pstore_register_kmsg(); | |
607 | if (psi->flags & PSTORE_FLAGS_CONSOLE) | |
df36ac1b | 608 | pstore_register_console(); |
c950fd6f | 609 | if (psi->flags & PSTORE_FLAGS_FTRACE) |
df36ac1b | 610 | pstore_register_ftrace(); |
c950fd6f | 611 | if (psi->flags & PSTORE_FLAGS_PMSG) |
9d5438f4 | 612 | pstore_register_pmsg(); |
ca01d6dd | 613 | |
6330d553 | 614 | /* Start watching for new records, if desired. */ |
a3f5f075 AV |
615 | if (pstore_update_ms >= 0) { |
616 | pstore_timer.expires = jiffies + | |
617 | msecs_to_jiffies(pstore_update_ms); | |
618 | add_timer(&pstore_timer); | |
619 | } | |
6dda9266 | 620 | |
42222c2a WL |
621 | /* |
622 | * Update the module parameter backend, so it is visible | |
623 | * through /sys/module/pstore/parameters/backend | |
624 | */ | |
625 | backend = psi->name; | |
626 | ||
ef748853 | 627 | pr_info("Registered %s as persistent store backend\n", psi->name); |
8e48b1a8 | 628 | |
1344dd86 KC |
629 | module_put(owner); |
630 | ||
ca01d6dd TL |
631 | return 0; |
632 | } | |
633 | EXPORT_SYMBOL_GPL(pstore_register); | |
634 | ||
ee1d2674 GT |
635 | void pstore_unregister(struct pstore_info *psi) |
636 | { | |
6330d553 KC |
637 | /* Stop timer and make sure all work has finished. */ |
638 | pstore_update_ms = -1; | |
639 | del_timer_sync(&pstore_timer); | |
640 | flush_work(&pstore_work); | |
641 | ||
c950fd6f | 642 | if (psi->flags & PSTORE_FLAGS_PMSG) |
a1db8060 | 643 | pstore_unregister_pmsg(); |
c950fd6f | 644 | if (psi->flags & PSTORE_FLAGS_FTRACE) |
a1db8060 | 645 | pstore_unregister_ftrace(); |
c950fd6f | 646 | if (psi->flags & PSTORE_FLAGS_CONSOLE) |
a1db8060 | 647 | pstore_unregister_console(); |
c950fd6f NK |
648 | if (psi->flags & PSTORE_FLAGS_DMESG) |
649 | pstore_unregister_kmsg(); | |
ee1d2674 GT |
650 | |
651 | free_buf_for_compression(); | |
652 | ||
653 | psinfo = NULL; | |
654 | backend = NULL; | |
655 | } | |
656 | EXPORT_SYMBOL_GPL(pstore_unregister); | |
657 | ||
634f8f51 KC |
658 | static void decompress_record(struct pstore_record *record) |
659 | { | |
bdabc8e7 | 660 | int ret; |
634f8f51 | 661 | int unzipped_len; |
bdabc8e7 | 662 | char *unzipped, *workspace; |
634f8f51 | 663 | |
4a16d1cb AK |
664 | if (!record->compressed) |
665 | return; | |
666 | ||
634f8f51 | 667 | /* Only PSTORE_TYPE_DMESG support compression. */ |
4a16d1cb | 668 | if (record->type != PSTORE_TYPE_DMESG) { |
634f8f51 KC |
669 | pr_warn("ignored compressed record type %d\n", record->type); |
670 | return; | |
671 | } | |
672 | ||
bdabc8e7 | 673 | /* Missing compression buffer means compression was not initialized. */ |
634f8f51 | 674 | if (!big_oops_buf) { |
bdabc8e7 | 675 | pr_warn("no decompression method initialized!\n"); |
634f8f51 KC |
676 | return; |
677 | } | |
678 | ||
bdabc8e7 KC |
679 | /* Allocate enough space to hold max decompression and ECC. */ |
680 | unzipped_len = big_oops_buf_sz; | |
681 | workspace = kmalloc(unzipped_len + record->ecc_notice_size, | |
682 | GFP_KERNEL); | |
683 | if (!workspace) | |
7e8cc8dc | 684 | return; |
7e8cc8dc | 685 | |
bdabc8e7 KC |
686 | /* After decompression "unzipped_len" is almost certainly smaller. */ |
687 | ret = crypto_comp_decompress(tfm, record->buf, record->size, | |
688 | workspace, &unzipped_len); | |
689 | if (ret) { | |
690 | pr_err("crypto_comp_decompress failed, ret = %d!\n", ret); | |
691 | kfree(workspace); | |
7e8cc8dc KC |
692 | return; |
693 | } | |
7e8cc8dc KC |
694 | |
695 | /* Append ECC notice to decompressed buffer. */ | |
bdabc8e7 | 696 | memcpy(workspace + unzipped_len, record->buf + record->size, |
7e8cc8dc KC |
697 | record->ecc_notice_size); |
698 | ||
bdabc8e7 KC |
699 | /* Copy decompressed contents into an minimum-sized allocation. */ |
700 | unzipped = kmemdup(workspace, unzipped_len + record->ecc_notice_size, | |
701 | GFP_KERNEL); | |
702 | kfree(workspace); | |
703 | if (!unzipped) | |
704 | return; | |
705 | ||
706 | /* Swap out compressed contents with decompressed contents. */ | |
7e8cc8dc | 707 | kfree(record->buf); |
bdabc8e7 | 708 | record->buf = unzipped; |
7e8cc8dc KC |
709 | record->size = unzipped_len; |
710 | record->compressed = false; | |
634f8f51 KC |
711 | } |
712 | ||
ca01d6dd | 713 | /* |
3a7d2fd1 | 714 | * Read all the records from one persistent store backend. Create |
6dda9266 LT |
715 | * files in our filesystem. Don't warn about -EEXIST errors |
716 | * when we are re-scanning the backing store looking to add new | |
717 | * error records. | |
ca01d6dd | 718 | */ |
3a7d2fd1 KC |
719 | void pstore_get_backend_records(struct pstore_info *psi, |
720 | struct dentry *root, int quiet) | |
ca01d6dd | 721 | { |
2a2b0acf | 722 | int failed = 0; |
656de42e | 723 | unsigned int stop_loop = 65536; |
ca01d6dd | 724 | |
3a7d2fd1 | 725 | if (!psi || !root) |
ca01d6dd TL |
726 | return; |
727 | ||
f6f82851 | 728 | mutex_lock(&psi->read_mutex); |
2174f6df | 729 | if (psi->open && psi->open(psi)) |
06cf91b4 CG |
730 | goto out; |
731 | ||
1dfff7dd KC |
732 | /* |
733 | * Backend callback read() allocates record.buf. decompress_record() | |
734 | * may reallocate record.buf. On success, pstore_mkfile() will keep | |
735 | * the record.buf, so free it only on failure. | |
736 | */ | |
656de42e | 737 | for (; stop_loop; stop_loop--) { |
2a2b0acf KC |
738 | struct pstore_record *record; |
739 | int rc; | |
740 | ||
741 | record = kzalloc(sizeof(*record), GFP_KERNEL); | |
742 | if (!record) { | |
743 | pr_err("out of memory creating record\n"); | |
744 | break; | |
745 | } | |
e581ca81 | 746 | pstore_record_init(record, psi); |
2a2b0acf KC |
747 | |
748 | record->size = psi->read(record); | |
749 | ||
750 | /* No more records left in backend? */ | |
f6525b96 DA |
751 | if (record->size <= 0) { |
752 | kfree(record); | |
2a2b0acf | 753 | break; |
f6525b96 | 754 | } |
2a2b0acf KC |
755 | |
756 | decompress_record(record); | |
3a7d2fd1 | 757 | rc = pstore_mkfile(root, record); |
1dfff7dd | 758 | if (rc) { |
83f70f07 | 759 | /* pstore_mkfile() did not take record, so free it. */ |
2a2b0acf | 760 | kfree(record->buf); |
83f70f07 | 761 | kfree(record); |
1dfff7dd KC |
762 | if (rc != -EEXIST || !quiet) |
763 | failed++; | |
764 | } | |
ca01d6dd | 765 | } |
2174f6df KC |
766 | if (psi->close) |
767 | psi->close(psi); | |
06cf91b4 | 768 | out: |
f6f82851 | 769 | mutex_unlock(&psi->read_mutex); |
ca01d6dd TL |
770 | |
771 | if (failed) | |
656de42e | 772 | pr_warn("failed to create %d record(s) from '%s'\n", |
ef748853 | 773 | failed, psi->name); |
656de42e KC |
774 | if (!stop_loop) |
775 | pr_err("looping? Too many records seen from '%s'\n", | |
776 | psi->name); | |
ca01d6dd TL |
777 | } |
778 | ||
6dda9266 LT |
779 | static void pstore_dowork(struct work_struct *work) |
780 | { | |
781 | pstore_get_records(1); | |
782 | } | |
783 | ||
24ed960a | 784 | static void pstore_timefunc(struct timer_list *unused) |
6dda9266 LT |
785 | { |
786 | if (pstore_new_entry) { | |
787 | pstore_new_entry = 0; | |
788 | schedule_work(&pstore_work); | |
789 | } | |
790 | ||
6330d553 KC |
791 | if (pstore_update_ms >= 0) |
792 | mod_timer(&pstore_timer, | |
793 | jiffies + msecs_to_jiffies(pstore_update_ms)); | |
6dda9266 LT |
794 | } |
795 | ||
fe1d4758 KC |
796 | void __init pstore_choose_compression(void) |
797 | { | |
798 | const struct pstore_zbackend *step; | |
799 | ||
800 | if (!compress) | |
801 | return; | |
802 | ||
803 | for (step = zbackends; step->name; step++) { | |
804 | if (!strcmp(compress, step->name)) { | |
805 | zbackend = step; | |
fe1d4758 KC |
806 | return; |
807 | } | |
808 | } | |
809 | } | |
810 | ||
cb095afd KC |
811 | static int __init pstore_init(void) |
812 | { | |
813 | int ret; | |
814 | ||
815 | pstore_choose_compression(); | |
816 | ||
41603165 JFG |
817 | /* |
818 | * Check if any pstore backends registered earlier but did not | |
819 | * initialize compression because crypto was not ready. If so, | |
820 | * initialize compression now. | |
821 | */ | |
95047b05 | 822 | allocate_buf_for_compression(); |
41603165 | 823 | |
cb095afd KC |
824 | ret = pstore_init_fs(); |
825 | if (ret) | |
826 | return ret; | |
827 | ||
828 | return 0; | |
829 | } | |
41603165 | 830 | late_initcall(pstore_init); |
cb095afd KC |
831 | |
832 | static void __exit pstore_exit(void) | |
833 | { | |
834 | pstore_exit_fs(); | |
835 | } | |
836 | module_exit(pstore_exit) | |
837 | ||
fe1d4758 KC |
838 | module_param(compress, charp, 0444); |
839 | MODULE_PARM_DESC(compress, "Pstore compression to use"); | |
840 | ||
dee28e72 MG |
841 | module_param(backend, charp, 0444); |
842 | MODULE_PARM_DESC(backend, "Pstore backend to use"); | |
cb095afd KC |
843 | |
844 | MODULE_AUTHOR("Tony Luck <tony.luck@intel.com>"); | |
845 | MODULE_LICENSE("GPL"); |