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 */ |
26fecbf7 | 104 | unsigned long kmsg_bytes = CONFIG_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 | ||
8126b1c7 | 146 | static bool pstore_cannot_block_path(enum kmsg_dump_reason reason) |
9f244e9c | 147 | { |
8126b1c7 JH |
148 | /* |
149 | * In case of NMI path, pstore shouldn't be blocked | |
150 | * regardless of reason. | |
151 | */ | |
9f244e9c SA |
152 | if (in_nmi()) |
153 | return true; | |
154 | ||
155 | switch (reason) { | |
156 | /* In panic case, other cpus are stopped by smp_send_stop(). */ | |
157 | case KMSG_DUMP_PANIC: | |
8126b1c7 JH |
158 | /* |
159 | * Emergency restart shouldn't be blocked by spinning on | |
160 | * pstore_info::buf_lock. | |
161 | */ | |
9f244e9c SA |
162 | case KMSG_DUMP_EMERG: |
163 | return true; | |
164 | default: | |
165 | return false; | |
166 | } | |
167 | } | |
9f244e9c | 168 | |
58eb5b67 | 169 | #if IS_ENABLED(CONFIG_PSTORE_DEFLATE_COMPRESS) |
cb3bee03 | 170 | static int zbufsize_deflate(size_t size) |
adb42f5e | 171 | { |
7de8fe2f AB |
172 | size_t cmpr; |
173 | ||
cb3bee03 | 174 | switch (size) { |
7de8fe2f AB |
175 | /* buffer range for efivars */ |
176 | case 1000 ... 2000: | |
177 | cmpr = 56; | |
178 | break; | |
179 | case 2001 ... 3000: | |
180 | cmpr = 54; | |
181 | break; | |
182 | case 3001 ... 3999: | |
183 | cmpr = 52; | |
184 | break; | |
185 | /* buffer range for nvram, erst */ | |
186 | case 4000 ... 10000: | |
187 | cmpr = 45; | |
188 | break; | |
189 | default: | |
190 | cmpr = 60; | |
191 | break; | |
192 | } | |
b0aad7a9 | 193 | |
cb3bee03 | 194 | return (size * 100) / cmpr; |
8cfc8ddc | 195 | } |
8cfc8ddc GT |
196 | #endif |
197 | ||
58eb5b67 | 198 | #if IS_ENABLED(CONFIG_PSTORE_LZO_COMPRESS) |
cb3bee03 | 199 | static int zbufsize_lzo(size_t size) |
8cfc8ddc | 200 | { |
cb3bee03 | 201 | return lzo1x_worst_compress(size); |
8cfc8ddc | 202 | } |
8cfc8ddc GT |
203 | #endif |
204 | ||
58eb5b67 | 205 | #if IS_ENABLED(CONFIG_PSTORE_LZ4_COMPRESS) || IS_ENABLED(CONFIG_PSTORE_LZ4HC_COMPRESS) |
cb3bee03 | 206 | static int zbufsize_lz4(size_t size) |
8cfc8ddc | 207 | { |
cb3bee03 | 208 | return LZ4_compressBound(size); |
8cfc8ddc | 209 | } |
239b7161 GT |
210 | #endif |
211 | ||
58eb5b67 | 212 | #if IS_ENABLED(CONFIG_PSTORE_842_COMPRESS) |
cb3bee03 | 213 | static int zbufsize_842(size_t size) |
239b7161 | 214 | { |
55597406 | 215 | return size; |
239b7161 | 216 | } |
8cfc8ddc GT |
217 | #endif |
218 | ||
1021bcf4 GT |
219 | #if IS_ENABLED(CONFIG_PSTORE_ZSTD_COMPRESS) |
220 | static int zbufsize_zstd(size_t size) | |
221 | { | |
cf30f6a5 | 222 | return zstd_compress_bound(size); |
1021bcf4 GT |
223 | } |
224 | #endif | |
225 | ||
fe1d4758 KC |
226 | static const struct pstore_zbackend *zbackend __ro_after_init; |
227 | ||
228 | static const struct pstore_zbackend zbackends[] = { | |
58eb5b67 | 229 | #if IS_ENABLED(CONFIG_PSTORE_DEFLATE_COMPRESS) |
fe1d4758 | 230 | { |
cb3bee03 GT |
231 | .zbufsize = zbufsize_deflate, |
232 | .name = "deflate", | |
fe1d4758 KC |
233 | }, |
234 | #endif | |
58eb5b67 | 235 | #if IS_ENABLED(CONFIG_PSTORE_LZO_COMPRESS) |
fe1d4758 | 236 | { |
cb3bee03 | 237 | .zbufsize = zbufsize_lzo, |
fe1d4758 KC |
238 | .name = "lzo", |
239 | }, | |
240 | #endif | |
58eb5b67 | 241 | #if IS_ENABLED(CONFIG_PSTORE_LZ4_COMPRESS) |
fe1d4758 | 242 | { |
cb3bee03 | 243 | .zbufsize = zbufsize_lz4, |
fe1d4758 KC |
244 | .name = "lz4", |
245 | }, | |
246 | #endif | |
58eb5b67 | 247 | #if IS_ENABLED(CONFIG_PSTORE_LZ4HC_COMPRESS) |
fe1d4758 | 248 | { |
cb3bee03 | 249 | .zbufsize = zbufsize_lz4, |
fe1d4758 KC |
250 | .name = "lz4hc", |
251 | }, | |
8cfc8ddc | 252 | #endif |
58eb5b67 | 253 | #if IS_ENABLED(CONFIG_PSTORE_842_COMPRESS) |
fe1d4758 | 254 | { |
cb3bee03 | 255 | .zbufsize = zbufsize_842, |
fe1d4758 KC |
256 | .name = "842", |
257 | }, | |
1021bcf4 GT |
258 | #endif |
259 | #if IS_ENABLED(CONFIG_PSTORE_ZSTD_COMPRESS) | |
260 | { | |
261 | .zbufsize = zbufsize_zstd, | |
262 | .name = "zstd", | |
263 | }, | |
fe1d4758 KC |
264 | #endif |
265 | { } | |
266 | }; | |
8cfc8ddc GT |
267 | |
268 | static int pstore_compress(const void *in, void *out, | |
cb3bee03 | 269 | unsigned int inlen, unsigned int outlen) |
8cfc8ddc | 270 | { |
cb3bee03 GT |
271 | int ret; |
272 | ||
19d8e914 | 273 | if (!IS_ENABLED(CONFIG_PSTORE_COMPRESS)) |
fd49e032 MC |
274 | return -EINVAL; |
275 | ||
cb3bee03 GT |
276 | ret = crypto_comp_compress(tfm, in, inlen, out, &outlen); |
277 | if (ret) { | |
278 | pr_err("crypto_comp_compress failed, ret = %d!\n", ret); | |
279 | return ret; | |
280 | } | |
281 | ||
282 | return outlen; | |
8cfc8ddc GT |
283 | } |
284 | ||
8cfc8ddc GT |
285 | static void allocate_buf_for_compression(void) |
286 | { | |
95047b05 KC |
287 | struct crypto_comp *ctx; |
288 | int size; | |
289 | char *buf; | |
290 | ||
291 | /* Skip if not built-in or compression backend not selected yet. */ | |
e698aaf3 | 292 | if (!IS_ENABLED(CONFIG_PSTORE_COMPRESS) || !zbackend) |
cb3bee03 GT |
293 | return; |
294 | ||
95047b05 KC |
295 | /* Skip if no pstore backend yet or compression init already done. */ |
296 | if (!psinfo || tfm) | |
297 | return; | |
298 | ||
cb3bee03 | 299 | if (!crypto_has_comp(zbackend->name, 0, 0)) { |
95047b05 | 300 | pr_err("Unknown compression: %s\n", zbackend->name); |
cb3bee03 GT |
301 | return; |
302 | } | |
303 | ||
95047b05 KC |
304 | size = zbackend->zbufsize(psinfo->bufsize); |
305 | if (size <= 0) { | |
306 | pr_err("Invalid compression size for %s: %d\n", | |
307 | zbackend->name, size); | |
cb3bee03 | 308 | return; |
95047b05 | 309 | } |
cb3bee03 | 310 | |
95047b05 KC |
311 | buf = kmalloc(size, GFP_KERNEL); |
312 | if (!buf) { | |
313 | pr_err("Failed %d byte compression buffer allocation for: %s\n", | |
314 | size, zbackend->name); | |
cb3bee03 GT |
315 | return; |
316 | } | |
317 | ||
95047b05 KC |
318 | ctx = crypto_alloc_comp(zbackend->name, 0, 0); |
319 | if (IS_ERR_OR_NULL(ctx)) { | |
320 | kfree(buf); | |
321 | pr_err("crypto_alloc_comp('%s') failed: %ld\n", zbackend->name, | |
322 | PTR_ERR(ctx)); | |
cb3bee03 | 323 | return; |
8cfc8ddc | 324 | } |
95047b05 KC |
325 | |
326 | /* A non-NULL big_oops_buf indicates compression is available. */ | |
327 | tfm = ctx; | |
328 | big_oops_buf_sz = size; | |
329 | big_oops_buf = buf; | |
330 | ||
0eed84ff | 331 | pr_info("Using crash dump compression: %s\n", zbackend->name); |
8cfc8ddc GT |
332 | } |
333 | ||
334 | static void free_buf_for_compression(void) | |
335 | { | |
a9fb94a9 | 336 | if (IS_ENABLED(CONFIG_PSTORE_COMPRESS) && tfm) { |
cb3bee03 | 337 | crypto_free_comp(tfm); |
a9fb94a9 PHS |
338 | tfm = NULL; |
339 | } | |
cb3bee03 GT |
340 | kfree(big_oops_buf); |
341 | big_oops_buf = NULL; | |
342 | big_oops_buf_sz = 0; | |
ee1d2674 GT |
343 | } |
344 | ||
b0aad7a9 AB |
345 | /* |
346 | * Called when compression fails, since the printk buffer | |
347 | * would be fetched for compression calling it again when | |
348 | * compression fails would have moved the iterator of | |
349 | * printk buffer which results in fetching old contents. | |
350 | * Copy the recent messages from big_oops_buf to psinfo->buf | |
351 | */ | |
352 | static size_t copy_kmsg_to_buffer(int hsize, size_t len) | |
353 | { | |
354 | size_t total_len; | |
355 | size_t diff; | |
356 | ||
357 | total_len = hsize + len; | |
358 | ||
359 | if (total_len > psinfo->bufsize) { | |
360 | diff = total_len - psinfo->bufsize + hsize; | |
361 | memcpy(psinfo->buf, big_oops_buf, hsize); | |
362 | memcpy(psinfo->buf + hsize, big_oops_buf + diff, | |
363 | psinfo->bufsize - hsize); | |
364 | total_len = psinfo->bufsize; | |
365 | } else | |
366 | memcpy(psinfo->buf, big_oops_buf, total_len); | |
367 | ||
368 | return total_len; | |
369 | } | |
370 | ||
e581ca81 KC |
371 | void pstore_record_init(struct pstore_record *record, |
372 | struct pstore_info *psinfo) | |
373 | { | |
374 | memset(record, 0, sizeof(*record)); | |
375 | ||
376 | record->psi = psinfo; | |
c7f3c595 KC |
377 | |
378 | /* Report zeroed timestamp if called before timekeeping has resumed. */ | |
7aaa822e | 379 | record->time = ns_to_timespec64(ktime_get_real_fast_ns()); |
e581ca81 KC |
380 | } |
381 | ||
ca01d6dd | 382 | /* |
0eed84ff KC |
383 | * callback from kmsg_dump. Save as much as we can (up to kmsg_bytes) from the |
384 | * end of the buffer. | |
ca01d6dd TL |
385 | */ |
386 | static void pstore_dump(struct kmsg_dumper *dumper, | |
e2ae715d | 387 | enum kmsg_dump_reason reason) |
ca01d6dd | 388 | { |
f9f3f02d | 389 | struct kmsg_dump_iter iter; |
e2ae715d | 390 | unsigned long total = 0; |
381b872c | 391 | const char *why; |
b94fdd07 | 392 | unsigned int part = 1; |
8126b1c7 | 393 | unsigned long flags = 0; |
e2ae715d | 394 | int ret; |
ca01d6dd | 395 | |
fb13cb8a | 396 | why = kmsg_dump_reason_str(reason); |
9f6af27f | 397 | |
8126b1c7 JH |
398 | if (pstore_cannot_block_path(reason)) { |
399 | if (!spin_trylock_irqsave(&psinfo->buf_lock, flags)) { | |
400 | pr_err("dump skipped in %s path because of concurrent dump\n", | |
401 | in_nmi() ? "NMI" : why); | |
959217c8 | 402 | return; |
9f244e9c | 403 | } |
8126b1c7 JH |
404 | } else { |
405 | spin_lock_irqsave(&psinfo->buf_lock, flags); | |
98e44fda | 406 | } |
ea84b580 | 407 | |
f9f3f02d JO |
408 | kmsg_dump_rewind(&iter); |
409 | ||
ca01d6dd TL |
410 | oopscount++; |
411 | while (total < kmsg_bytes) { | |
e2ae715d | 412 | char *dst; |
76cc9580 KC |
413 | size_t dst_size; |
414 | int header_size; | |
b0aad7a9 | 415 | int zipped_len = -1; |
76cc9580 | 416 | size_t dump_size; |
e581ca81 KC |
417 | struct pstore_record record; |
418 | ||
419 | pstore_record_init(&record, psinfo); | |
420 | record.type = PSTORE_TYPE_DMESG; | |
421 | record.count = oopscount; | |
422 | record.reason = reason; | |
423 | record.part = part; | |
424 | record.buf = psinfo->buf; | |
e2ae715d | 425 | |
ea84b580 | 426 | if (big_oops_buf) { |
b0aad7a9 | 427 | dst = big_oops_buf; |
76cc9580 | 428 | dst_size = big_oops_buf_sz; |
235f6d15 NK |
429 | } else { |
430 | dst = psinfo->buf; | |
76cc9580 | 431 | dst_size = psinfo->bufsize; |
235f6d15 NK |
432 | } |
433 | ||
76cc9580 KC |
434 | /* Write dump header. */ |
435 | header_size = snprintf(dst, dst_size, "%s#%d Part%u\n", why, | |
436 | oopscount, part); | |
437 | dst_size -= header_size; | |
ca01d6dd | 438 | |
76cc9580 | 439 | /* Write dump contents. */ |
f9f3f02d | 440 | if (!kmsg_dump_get_buffer(&iter, true, dst + header_size, |
76cc9580 | 441 | dst_size, &dump_size)) |
235f6d15 | 442 | break; |
b0aad7a9 | 443 | |
ea84b580 | 444 | if (big_oops_buf) { |
b0aad7a9 | 445 | zipped_len = pstore_compress(dst, psinfo->buf, |
76cc9580 KC |
446 | header_size + dump_size, |
447 | psinfo->bufsize); | |
b0aad7a9 AB |
448 | |
449 | if (zipped_len > 0) { | |
76cc9580 KC |
450 | record.compressed = true; |
451 | record.size = zipped_len; | |
b0aad7a9 | 452 | } else { |
76cc9580 KC |
453 | record.size = copy_kmsg_to_buffer(header_size, |
454 | dump_size); | |
b0aad7a9 AB |
455 | } |
456 | } else { | |
76cc9580 | 457 | record.size = header_size + dump_size; |
b0aad7a9 | 458 | } |
ca01d6dd | 459 | |
76cc9580 | 460 | ret = psinfo->write(&record); |
78c83c82 | 461 | if (ret == 0 && reason == KMSG_DUMP_OOPS) { |
6dda9266 | 462 | pstore_new_entry = 1; |
78c83c82 KC |
463 | pstore_timer_kick(); |
464 | } | |
e2ae715d | 465 | |
76cc9580 | 466 | total += record.size; |
56280682 | 467 | part++; |
ca01d6dd | 468 | } |
8126b1c7 | 469 | spin_unlock_irqrestore(&psinfo->buf_lock, flags); |
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 = { | |
f29e5956 | 506 | .write = pstore_console_write, |
f29e5956 AV |
507 | .index = -1, |
508 | }; | |
509 | ||
510 | static void pstore_register_console(void) | |
511 | { | |
d195c390 KC |
512 | /* Show which backend is going to get console writes. */ |
513 | strscpy(pstore_console.name, psinfo->name, | |
514 | sizeof(pstore_console.name)); | |
b7753fc7 KC |
515 | /* |
516 | * Always initialize flags here since prior unregister_console() | |
517 | * calls may have changed settings (specifically CON_ENABLED). | |
518 | */ | |
519 | pstore_console.flags = CON_PRINTBUFFER | CON_ENABLED | CON_ANYTIME; | |
f29e5956 AV |
520 | register_console(&pstore_console); |
521 | } | |
ee1d2674 GT |
522 | |
523 | static void pstore_unregister_console(void) | |
524 | { | |
525 | unregister_console(&pstore_console); | |
526 | } | |
f29e5956 AV |
527 | #else |
528 | static void pstore_register_console(void) {} | |
ee1d2674 | 529 | static void pstore_unregister_console(void) {} |
f29e5956 AV |
530 | #endif |
531 | ||
4c9ec219 KC |
532 | static int pstore_write_user_compat(struct pstore_record *record, |
533 | const char __user *buf) | |
5bf6d1b9 | 534 | { |
30800d99 KC |
535 | int ret = 0; |
536 | ||
537 | if (record->buf) | |
538 | return -EINVAL; | |
539 | ||
077090af | 540 | record->buf = memdup_user(buf, record->size); |
dfd6fa39 | 541 | if (IS_ERR(record->buf)) { |
077090af | 542 | ret = PTR_ERR(record->buf); |
30800d99 | 543 | goto out; |
5bf6d1b9 | 544 | } |
30800d99 KC |
545 | |
546 | ret = record->psi->write(record); | |
547 | ||
30800d99 | 548 | kfree(record->buf); |
077090af | 549 | out: |
30800d99 KC |
550 | record->buf = NULL; |
551 | ||
552 | return unlikely(ret < 0) ? ret : record->size; | |
5bf6d1b9 MS |
553 | } |
554 | ||
ca01d6dd TL |
555 | /* |
556 | * platform specific persistent storage driver registers with | |
557 | * us here. If pstore is already mounted, call the platform | |
558 | * read function right away to populate the file system. If not | |
559 | * then the pstore mount code will call us later to fill out | |
560 | * the file system. | |
ca01d6dd TL |
561 | */ |
562 | int pstore_register(struct pstore_info *psi) | |
563 | { | |
0d7cd09a KC |
564 | if (backend && strcmp(backend, psi->name)) { |
565 | pr_warn("ignoring unexpected backend '%s'\n", psi->name); | |
8e48b1a8 | 566 | return -EPERM; |
0d7cd09a | 567 | } |
8e48b1a8 | 568 | |
4c9ec219 KC |
569 | /* Sanity check flags. */ |
570 | if (!psi->flags) { | |
571 | pr_warn("backend '%s' must support at least one frontend\n", | |
572 | psi->name); | |
573 | return -EINVAL; | |
574 | } | |
575 | ||
576 | /* Check for required functions. */ | |
577 | if (!psi->read || !psi->write) { | |
578 | pr_warn("backend '%s' must implement read() and write()\n", | |
579 | psi->name); | |
580 | return -EINVAL; | |
581 | } | |
582 | ||
cab12fd0 | 583 | mutex_lock(&psinfo_lock); |
ca01d6dd | 584 | if (psinfo) { |
0d7cd09a KC |
585 | pr_warn("backend '%s' already loaded: ignoring '%s'\n", |
586 | psinfo->name, psi->name); | |
cab12fd0 | 587 | mutex_unlock(&psinfo_lock); |
ca01d6dd TL |
588 | return -EBUSY; |
589 | } | |
dee28e72 | 590 | |
4c9ec219 KC |
591 | if (!psi->write_user) |
592 | psi->write_user = pstore_write_user_compat; | |
ca01d6dd | 593 | psinfo = psi; |
f6f82851 | 594 | mutex_init(&psinfo->read_mutex); |
8126b1c7 | 595 | spin_lock_init(&psinfo->buf_lock); |
ca01d6dd | 596 | |
8880fa32 KC |
597 | if (psi->flags & PSTORE_FLAGS_DMESG) |
598 | allocate_buf_for_compression(); | |
b0aad7a9 | 599 | |
27e5041a | 600 | pstore_get_records(0); |
ca01d6dd | 601 | |
3524e688 PT |
602 | if (psi->flags & PSTORE_FLAGS_DMESG) { |
603 | pstore_dumper.max_reason = psinfo->max_reason; | |
c950fd6f | 604 | pstore_register_kmsg(); |
3524e688 | 605 | } |
c950fd6f | 606 | if (psi->flags & PSTORE_FLAGS_CONSOLE) |
df36ac1b | 607 | pstore_register_console(); |
c950fd6f | 608 | if (psi->flags & PSTORE_FLAGS_FTRACE) |
df36ac1b | 609 | pstore_register_ftrace(); |
c950fd6f | 610 | if (psi->flags & PSTORE_FLAGS_PMSG) |
9d5438f4 | 611 | pstore_register_pmsg(); |
ca01d6dd | 612 | |
6330d553 | 613 | /* Start watching for new records, if desired. */ |
78c83c82 | 614 | pstore_timer_kick(); |
6dda9266 | 615 | |
42222c2a WL |
616 | /* |
617 | * Update the module parameter backend, so it is visible | |
618 | * through /sys/module/pstore/parameters/backend | |
619 | */ | |
563ca40d | 620 | backend = kstrdup(psi->name, GFP_KERNEL); |
42222c2a | 621 | |
ef748853 | 622 | pr_info("Registered %s as persistent store backend\n", psi->name); |
8e48b1a8 | 623 | |
6248a066 | 624 | mutex_unlock(&psinfo_lock); |
ca01d6dd TL |
625 | return 0; |
626 | } | |
627 | EXPORT_SYMBOL_GPL(pstore_register); | |
628 | ||
ee1d2674 GT |
629 | void pstore_unregister(struct pstore_info *psi) |
630 | { | |
6248a066 KC |
631 | /* It's okay to unregister nothing. */ |
632 | if (!psi) | |
633 | return; | |
634 | ||
635 | mutex_lock(&psinfo_lock); | |
636 | ||
637 | /* Only one backend can be registered at a time. */ | |
638 | if (WARN_ON(psi != psinfo)) { | |
639 | mutex_unlock(&psinfo_lock); | |
640 | return; | |
641 | } | |
642 | ||
78c83c82 | 643 | /* Unregister all callbacks. */ |
c950fd6f | 644 | if (psi->flags & PSTORE_FLAGS_PMSG) |
a1db8060 | 645 | pstore_unregister_pmsg(); |
c950fd6f | 646 | if (psi->flags & PSTORE_FLAGS_FTRACE) |
a1db8060 | 647 | pstore_unregister_ftrace(); |
c950fd6f | 648 | if (psi->flags & PSTORE_FLAGS_CONSOLE) |
a1db8060 | 649 | pstore_unregister_console(); |
c950fd6f NK |
650 | if (psi->flags & PSTORE_FLAGS_DMESG) |
651 | pstore_unregister_kmsg(); | |
ee1d2674 | 652 | |
78c83c82 KC |
653 | /* Stop timer and make sure all work has finished. */ |
654 | del_timer_sync(&pstore_timer); | |
655 | flush_work(&pstore_work); | |
656 | ||
609e28bb KC |
657 | /* Remove all backend records from filesystem tree. */ |
658 | pstore_put_backend_records(psi); | |
659 | ||
ee1d2674 GT |
660 | free_buf_for_compression(); |
661 | ||
662 | psinfo = NULL; | |
563ca40d | 663 | kfree(backend); |
ee1d2674 | 664 | backend = NULL; |
6248a066 | 665 | mutex_unlock(&psinfo_lock); |
ee1d2674 GT |
666 | } |
667 | EXPORT_SYMBOL_GPL(pstore_unregister); | |
668 | ||
634f8f51 KC |
669 | static void decompress_record(struct pstore_record *record) |
670 | { | |
bdabc8e7 | 671 | int ret; |
634f8f51 | 672 | int unzipped_len; |
bdabc8e7 | 673 | char *unzipped, *workspace; |
634f8f51 | 674 | |
19d8e914 | 675 | if (!IS_ENABLED(CONFIG_PSTORE_COMPRESS) || !record->compressed) |
4a16d1cb AK |
676 | return; |
677 | ||
634f8f51 | 678 | /* Only PSTORE_TYPE_DMESG support compression. */ |
4a16d1cb | 679 | if (record->type != PSTORE_TYPE_DMESG) { |
634f8f51 KC |
680 | pr_warn("ignored compressed record type %d\n", record->type); |
681 | return; | |
682 | } | |
683 | ||
bdabc8e7 | 684 | /* Missing compression buffer means compression was not initialized. */ |
634f8f51 | 685 | if (!big_oops_buf) { |
bdabc8e7 | 686 | pr_warn("no decompression method initialized!\n"); |
634f8f51 KC |
687 | return; |
688 | } | |
689 | ||
bdabc8e7 KC |
690 | /* Allocate enough space to hold max decompression and ECC. */ |
691 | unzipped_len = big_oops_buf_sz; | |
692 | workspace = kmalloc(unzipped_len + record->ecc_notice_size, | |
693 | GFP_KERNEL); | |
694 | if (!workspace) | |
7e8cc8dc | 695 | return; |
7e8cc8dc | 696 | |
bdabc8e7 KC |
697 | /* After decompression "unzipped_len" is almost certainly smaller. */ |
698 | ret = crypto_comp_decompress(tfm, record->buf, record->size, | |
699 | workspace, &unzipped_len); | |
700 | if (ret) { | |
701 | pr_err("crypto_comp_decompress failed, ret = %d!\n", ret); | |
702 | kfree(workspace); | |
7e8cc8dc KC |
703 | return; |
704 | } | |
7e8cc8dc KC |
705 | |
706 | /* Append ECC notice to decompressed buffer. */ | |
bdabc8e7 | 707 | memcpy(workspace + unzipped_len, record->buf + record->size, |
7e8cc8dc KC |
708 | record->ecc_notice_size); |
709 | ||
bdabc8e7 KC |
710 | /* Copy decompressed contents into an minimum-sized allocation. */ |
711 | unzipped = kmemdup(workspace, unzipped_len + record->ecc_notice_size, | |
712 | GFP_KERNEL); | |
713 | kfree(workspace); | |
714 | if (!unzipped) | |
715 | return; | |
716 | ||
717 | /* Swap out compressed contents with decompressed contents. */ | |
7e8cc8dc | 718 | kfree(record->buf); |
bdabc8e7 | 719 | record->buf = unzipped; |
7e8cc8dc KC |
720 | record->size = unzipped_len; |
721 | record->compressed = false; | |
634f8f51 KC |
722 | } |
723 | ||
ca01d6dd | 724 | /* |
3a7d2fd1 | 725 | * Read all the records from one persistent store backend. Create |
6dda9266 LT |
726 | * files in our filesystem. Don't warn about -EEXIST errors |
727 | * when we are re-scanning the backing store looking to add new | |
728 | * error records. | |
ca01d6dd | 729 | */ |
3a7d2fd1 KC |
730 | void pstore_get_backend_records(struct pstore_info *psi, |
731 | struct dentry *root, int quiet) | |
ca01d6dd | 732 | { |
2a2b0acf | 733 | int failed = 0; |
656de42e | 734 | unsigned int stop_loop = 65536; |
ca01d6dd | 735 | |
3a7d2fd1 | 736 | if (!psi || !root) |
ca01d6dd TL |
737 | return; |
738 | ||
f6f82851 | 739 | mutex_lock(&psi->read_mutex); |
2174f6df | 740 | if (psi->open && psi->open(psi)) |
06cf91b4 CG |
741 | goto out; |
742 | ||
1dfff7dd KC |
743 | /* |
744 | * Backend callback read() allocates record.buf. decompress_record() | |
745 | * may reallocate record.buf. On success, pstore_mkfile() will keep | |
746 | * the record.buf, so free it only on failure. | |
747 | */ | |
656de42e | 748 | for (; stop_loop; stop_loop--) { |
2a2b0acf KC |
749 | struct pstore_record *record; |
750 | int rc; | |
751 | ||
752 | record = kzalloc(sizeof(*record), GFP_KERNEL); | |
753 | if (!record) { | |
754 | pr_err("out of memory creating record\n"); | |
755 | break; | |
756 | } | |
e581ca81 | 757 | pstore_record_init(record, psi); |
2a2b0acf KC |
758 | |
759 | record->size = psi->read(record); | |
760 | ||
761 | /* No more records left in backend? */ | |
f6525b96 DA |
762 | if (record->size <= 0) { |
763 | kfree(record); | |
2a2b0acf | 764 | break; |
f6525b96 | 765 | } |
2a2b0acf KC |
766 | |
767 | decompress_record(record); | |
3a7d2fd1 | 768 | rc = pstore_mkfile(root, record); |
1dfff7dd | 769 | if (rc) { |
83f70f07 | 770 | /* pstore_mkfile() did not take record, so free it. */ |
2a2b0acf | 771 | kfree(record->buf); |
83f70f07 | 772 | kfree(record); |
1dfff7dd KC |
773 | if (rc != -EEXIST || !quiet) |
774 | failed++; | |
775 | } | |
ca01d6dd | 776 | } |
2174f6df KC |
777 | if (psi->close) |
778 | psi->close(psi); | |
06cf91b4 | 779 | out: |
f6f82851 | 780 | mutex_unlock(&psi->read_mutex); |
ca01d6dd TL |
781 | |
782 | if (failed) | |
656de42e | 783 | pr_warn("failed to create %d record(s) from '%s'\n", |
ef748853 | 784 | failed, psi->name); |
656de42e KC |
785 | if (!stop_loop) |
786 | pr_err("looping? Too many records seen from '%s'\n", | |
787 | psi->name); | |
ca01d6dd TL |
788 | } |
789 | ||
6dda9266 LT |
790 | static void pstore_dowork(struct work_struct *work) |
791 | { | |
792 | pstore_get_records(1); | |
793 | } | |
794 | ||
24ed960a | 795 | static void pstore_timefunc(struct timer_list *unused) |
6dda9266 LT |
796 | { |
797 | if (pstore_new_entry) { | |
798 | pstore_new_entry = 0; | |
799 | schedule_work(&pstore_work); | |
800 | } | |
801 | ||
78c83c82 | 802 | pstore_timer_kick(); |
6dda9266 LT |
803 | } |
804 | ||
8d82cee2 | 805 | static void __init pstore_choose_compression(void) |
fe1d4758 KC |
806 | { |
807 | const struct pstore_zbackend *step; | |
808 | ||
809 | if (!compress) | |
810 | return; | |
811 | ||
812 | for (step = zbackends; step->name; step++) { | |
813 | if (!strcmp(compress, step->name)) { | |
814 | zbackend = step; | |
fe1d4758 KC |
815 | return; |
816 | } | |
817 | } | |
818 | } | |
819 | ||
cb095afd KC |
820 | static int __init pstore_init(void) |
821 | { | |
822 | int ret; | |
823 | ||
824 | pstore_choose_compression(); | |
825 | ||
41603165 JFG |
826 | /* |
827 | * Check if any pstore backends registered earlier but did not | |
828 | * initialize compression because crypto was not ready. If so, | |
829 | * initialize compression now. | |
830 | */ | |
95047b05 | 831 | allocate_buf_for_compression(); |
41603165 | 832 | |
cb095afd KC |
833 | ret = pstore_init_fs(); |
834 | if (ret) | |
8a57d6d4 | 835 | free_buf_for_compression(); |
cb095afd | 836 | |
8a57d6d4 | 837 | return ret; |
cb095afd | 838 | } |
41603165 | 839 | late_initcall(pstore_init); |
cb095afd KC |
840 | |
841 | static void __exit pstore_exit(void) | |
842 | { | |
843 | pstore_exit_fs(); | |
844 | } | |
845 | module_exit(pstore_exit) | |
846 | ||
cb095afd KC |
847 | MODULE_AUTHOR("Tony Luck <tony.luck@intel.com>"); |
848 | MODULE_LICENSE("GPL"); |