Commit | Line | Data |
---|---|---|
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 | |
8f5de3fd GP |
92 | /* How much of the kernel log to snapshot */ |
93 | unsigned long kmsg_bytes = CONFIG_PSTORE_DEFAULT_KMSG_BYTES; | |
94 | module_param(kmsg_bytes, ulong, 0444); | |
95 | MODULE_PARM_DESC(kmsg_bytes, "amount of kernel log to snapshot (in bytes)"); | |
96 | ||
b0aad7a9 | 97 | /* Compression parameters */ |
40158dbf | 98 | static struct crypto_comp *tfm; |
8cfc8ddc GT |
99 | |
100 | struct pstore_zbackend { | |
cb3bee03 | 101 | int (*zbufsize)(size_t size); |
8cfc8ddc GT |
102 | const char *name; |
103 | }; | |
b0aad7a9 AB |
104 | |
105 | static char *big_oops_buf; | |
106 | static size_t big_oops_buf_sz; | |
107 | ||
366f7e7a | 108 | void pstore_set_kmsg_bytes(int bytes) |
ca01d6dd | 109 | { |
366f7e7a | 110 | kmsg_bytes = bytes; |
ca01d6dd TL |
111 | } |
112 | ||
ca01d6dd TL |
113 | /* Tag each group of saved records with a sequence number */ |
114 | static int oopscount; | |
115 | ||
f0f23e54 JFG |
116 | const char *pstore_type_to_name(enum pstore_type_id type) |
117 | { | |
118 | BUILD_BUG_ON(ARRAY_SIZE(pstore_type_names) != PSTORE_TYPE_MAX); | |
119 | ||
120 | if (WARN_ON_ONCE(type >= PSTORE_TYPE_MAX)) | |
121 | return "unknown"; | |
122 | ||
123 | return pstore_type_names[type]; | |
124 | } | |
125 | EXPORT_SYMBOL_GPL(pstore_type_to_name); | |
126 | ||
127 | enum pstore_type_id pstore_name_to_type(const char *name) | |
128 | { | |
129 | int i; | |
130 | ||
131 | for (i = 0; i < PSTORE_TYPE_MAX; i++) { | |
132 | if (!strcmp(pstore_type_names[i], name)) | |
133 | return i; | |
134 | } | |
135 | ||
136 | return PSTORE_TYPE_MAX; | |
137 | } | |
138 | EXPORT_SYMBOL_GPL(pstore_name_to_type); | |
139 | ||
78c83c82 KC |
140 | static void pstore_timer_kick(void) |
141 | { | |
142 | if (pstore_update_ms < 0) | |
143 | return; | |
144 | ||
145 | mod_timer(&pstore_timer, jiffies + msecs_to_jiffies(pstore_update_ms)); | |
146 | } | |
147 | ||
8126b1c7 | 148 | static bool pstore_cannot_block_path(enum kmsg_dump_reason reason) |
9f244e9c | 149 | { |
8126b1c7 JH |
150 | /* |
151 | * In case of NMI path, pstore shouldn't be blocked | |
152 | * regardless of reason. | |
153 | */ | |
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: | |
8126b1c7 JH |
160 | /* |
161 | * Emergency restart shouldn't be blocked by spinning on | |
162 | * pstore_info::buf_lock. | |
163 | */ | |
9f244e9c SA |
164 | case KMSG_DUMP_EMERG: |
165 | return true; | |
166 | default: | |
167 | return false; | |
168 | } | |
169 | } | |
9f244e9c | 170 | |
58eb5b67 | 171 | #if IS_ENABLED(CONFIG_PSTORE_DEFLATE_COMPRESS) |
cb3bee03 | 172 | static int zbufsize_deflate(size_t size) |
adb42f5e | 173 | { |
7de8fe2f AB |
174 | size_t cmpr; |
175 | ||
cb3bee03 | 176 | switch (size) { |
7de8fe2f AB |
177 | /* buffer range for efivars */ |
178 | case 1000 ... 2000: | |
179 | cmpr = 56; | |
180 | break; | |
181 | case 2001 ... 3000: | |
182 | cmpr = 54; | |
183 | break; | |
184 | case 3001 ... 3999: | |
185 | cmpr = 52; | |
186 | break; | |
187 | /* buffer range for nvram, erst */ | |
188 | case 4000 ... 10000: | |
189 | cmpr = 45; | |
190 | break; | |
191 | default: | |
192 | cmpr = 60; | |
193 | break; | |
194 | } | |
b0aad7a9 | 195 | |
cb3bee03 | 196 | return (size * 100) / cmpr; |
8cfc8ddc | 197 | } |
8cfc8ddc GT |
198 | #endif |
199 | ||
58eb5b67 | 200 | #if IS_ENABLED(CONFIG_PSTORE_LZO_COMPRESS) |
cb3bee03 | 201 | static int zbufsize_lzo(size_t size) |
8cfc8ddc | 202 | { |
cb3bee03 | 203 | return lzo1x_worst_compress(size); |
8cfc8ddc | 204 | } |
8cfc8ddc GT |
205 | #endif |
206 | ||
58eb5b67 | 207 | #if IS_ENABLED(CONFIG_PSTORE_LZ4_COMPRESS) || IS_ENABLED(CONFIG_PSTORE_LZ4HC_COMPRESS) |
cb3bee03 | 208 | static int zbufsize_lz4(size_t size) |
8cfc8ddc | 209 | { |
cb3bee03 | 210 | return LZ4_compressBound(size); |
8cfc8ddc | 211 | } |
239b7161 GT |
212 | #endif |
213 | ||
58eb5b67 | 214 | #if IS_ENABLED(CONFIG_PSTORE_842_COMPRESS) |
cb3bee03 | 215 | static int zbufsize_842(size_t size) |
239b7161 | 216 | { |
55597406 | 217 | return size; |
239b7161 | 218 | } |
8cfc8ddc GT |
219 | #endif |
220 | ||
1021bcf4 GT |
221 | #if IS_ENABLED(CONFIG_PSTORE_ZSTD_COMPRESS) |
222 | static int zbufsize_zstd(size_t size) | |
223 | { | |
cf30f6a5 | 224 | return zstd_compress_bound(size); |
1021bcf4 GT |
225 | } |
226 | #endif | |
227 | ||
fe1d4758 KC |
228 | static const struct pstore_zbackend *zbackend __ro_after_init; |
229 | ||
230 | static const struct pstore_zbackend zbackends[] = { | |
58eb5b67 | 231 | #if IS_ENABLED(CONFIG_PSTORE_DEFLATE_COMPRESS) |
fe1d4758 | 232 | { |
cb3bee03 GT |
233 | .zbufsize = zbufsize_deflate, |
234 | .name = "deflate", | |
fe1d4758 KC |
235 | }, |
236 | #endif | |
58eb5b67 | 237 | #if IS_ENABLED(CONFIG_PSTORE_LZO_COMPRESS) |
fe1d4758 | 238 | { |
cb3bee03 | 239 | .zbufsize = zbufsize_lzo, |
fe1d4758 KC |
240 | .name = "lzo", |
241 | }, | |
242 | #endif | |
58eb5b67 | 243 | #if IS_ENABLED(CONFIG_PSTORE_LZ4_COMPRESS) |
fe1d4758 | 244 | { |
cb3bee03 | 245 | .zbufsize = zbufsize_lz4, |
fe1d4758 KC |
246 | .name = "lz4", |
247 | }, | |
248 | #endif | |
58eb5b67 | 249 | #if IS_ENABLED(CONFIG_PSTORE_LZ4HC_COMPRESS) |
fe1d4758 | 250 | { |
cb3bee03 | 251 | .zbufsize = zbufsize_lz4, |
fe1d4758 KC |
252 | .name = "lz4hc", |
253 | }, | |
8cfc8ddc | 254 | #endif |
58eb5b67 | 255 | #if IS_ENABLED(CONFIG_PSTORE_842_COMPRESS) |
fe1d4758 | 256 | { |
cb3bee03 | 257 | .zbufsize = zbufsize_842, |
fe1d4758 KC |
258 | .name = "842", |
259 | }, | |
1021bcf4 GT |
260 | #endif |
261 | #if IS_ENABLED(CONFIG_PSTORE_ZSTD_COMPRESS) | |
262 | { | |
263 | .zbufsize = zbufsize_zstd, | |
264 | .name = "zstd", | |
265 | }, | |
fe1d4758 KC |
266 | #endif |
267 | { } | |
268 | }; | |
8cfc8ddc GT |
269 | |
270 | static int pstore_compress(const void *in, void *out, | |
cb3bee03 | 271 | unsigned int inlen, unsigned int outlen) |
8cfc8ddc | 272 | { |
cb3bee03 GT |
273 | int ret; |
274 | ||
19d8e914 | 275 | if (!IS_ENABLED(CONFIG_PSTORE_COMPRESS)) |
fd49e032 MC |
276 | return -EINVAL; |
277 | ||
40158dbf | 278 | ret = crypto_comp_compress(tfm, in, inlen, out, &outlen); |
cb3bee03 GT |
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 | { | |
40158dbf | 289 | struct crypto_comp *ctx; |
95047b05 KC |
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 | ||
40158dbf | 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 | ||
40158dbf GP |
320 | ctx = crypto_alloc_comp(zbackend->name, 0, 0); |
321 | if (IS_ERR_OR_NULL(ctx)) { | |
95047b05 KC |
322 | kfree(buf); |
323 | pr_err("crypto_alloc_comp('%s') failed: %ld\n", zbackend->name, | |
40158dbf | 324 | PTR_ERR(ctx)); |
cb3bee03 | 325 | return; |
8cfc8ddc | 326 | } |
95047b05 KC |
327 | |
328 | /* A non-NULL big_oops_buf indicates compression is available. */ | |
40158dbf | 329 | tfm = ctx; |
95047b05 KC |
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) { |
40158dbf | 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 | { |
f9f3f02d | 391 | struct kmsg_dump_iter iter; |
e2ae715d | 392 | unsigned long total = 0; |
381b872c | 393 | const char *why; |
b94fdd07 | 394 | unsigned int part = 1; |
8126b1c7 | 395 | unsigned long flags = 0; |
38b91847 | 396 | int saved_ret = 0; |
e2ae715d | 397 | int ret; |
ca01d6dd | 398 | |
fb13cb8a | 399 | why = kmsg_dump_reason_str(reason); |
9f6af27f | 400 | |
8126b1c7 JH |
401 | if (pstore_cannot_block_path(reason)) { |
402 | if (!spin_trylock_irqsave(&psinfo->buf_lock, flags)) { | |
403 | pr_err("dump skipped in %s path because of concurrent dump\n", | |
404 | in_nmi() ? "NMI" : why); | |
959217c8 | 405 | return; |
9f244e9c | 406 | } |
8126b1c7 JH |
407 | } else { |
408 | spin_lock_irqsave(&psinfo->buf_lock, flags); | |
98e44fda | 409 | } |
ea84b580 | 410 | |
f9f3f02d JO |
411 | kmsg_dump_rewind(&iter); |
412 | ||
ca01d6dd TL |
413 | oopscount++; |
414 | while (total < kmsg_bytes) { | |
e2ae715d | 415 | char *dst; |
76cc9580 KC |
416 | size_t dst_size; |
417 | int header_size; | |
b0aad7a9 | 418 | int zipped_len = -1; |
76cc9580 | 419 | size_t dump_size; |
e581ca81 KC |
420 | struct pstore_record record; |
421 | ||
422 | pstore_record_init(&record, psinfo); | |
423 | record.type = PSTORE_TYPE_DMESG; | |
424 | record.count = oopscount; | |
425 | record.reason = reason; | |
426 | record.part = part; | |
427 | record.buf = psinfo->buf; | |
e2ae715d | 428 | |
ea84b580 | 429 | if (big_oops_buf) { |
b0aad7a9 | 430 | dst = big_oops_buf; |
76cc9580 | 431 | dst_size = big_oops_buf_sz; |
235f6d15 NK |
432 | } else { |
433 | dst = psinfo->buf; | |
76cc9580 | 434 | dst_size = psinfo->bufsize; |
235f6d15 NK |
435 | } |
436 | ||
76cc9580 KC |
437 | /* Write dump header. */ |
438 | header_size = snprintf(dst, dst_size, "%s#%d Part%u\n", why, | |
439 | oopscount, part); | |
440 | dst_size -= header_size; | |
ca01d6dd | 441 | |
76cc9580 | 442 | /* Write dump contents. */ |
f9f3f02d | 443 | if (!kmsg_dump_get_buffer(&iter, true, dst + header_size, |
76cc9580 | 444 | dst_size, &dump_size)) |
235f6d15 | 445 | break; |
b0aad7a9 | 446 | |
ea84b580 | 447 | if (big_oops_buf) { |
b0aad7a9 | 448 | zipped_len = pstore_compress(dst, psinfo->buf, |
76cc9580 KC |
449 | header_size + dump_size, |
450 | psinfo->bufsize); | |
b0aad7a9 AB |
451 | |
452 | if (zipped_len > 0) { | |
76cc9580 KC |
453 | record.compressed = true; |
454 | record.size = zipped_len; | |
b0aad7a9 | 455 | } else { |
76cc9580 KC |
456 | record.size = copy_kmsg_to_buffer(header_size, |
457 | dump_size); | |
b0aad7a9 AB |
458 | } |
459 | } else { | |
76cc9580 | 460 | record.size = header_size + dump_size; |
b0aad7a9 | 461 | } |
ca01d6dd | 462 | |
76cc9580 | 463 | ret = psinfo->write(&record); |
78c83c82 | 464 | if (ret == 0 && reason == KMSG_DUMP_OOPS) { |
6dda9266 | 465 | pstore_new_entry = 1; |
78c83c82 | 466 | pstore_timer_kick(); |
38b91847 GP |
467 | } else { |
468 | /* Preserve only the first non-zero returned value. */ | |
469 | if (!saved_ret) | |
470 | saved_ret = ret; | |
78c83c82 | 471 | } |
e2ae715d | 472 | |
76cc9580 | 473 | total += record.size; |
56280682 | 474 | part++; |
ca01d6dd | 475 | } |
8126b1c7 | 476 | spin_unlock_irqrestore(&psinfo->buf_lock, flags); |
38b91847 GP |
477 | |
478 | if (saved_ret) { | |
479 | pr_err_once("backend (%s) writing error (%d)\n", psinfo->name, | |
480 | saved_ret); | |
481 | } | |
ca01d6dd TL |
482 | } |
483 | ||
484 | static struct kmsg_dumper pstore_dumper = { | |
485 | .dump = pstore_dump, | |
486 | }; | |
487 | ||
306e5c2a GT |
488 | /* |
489 | * Register with kmsg_dump to save last part of console log on panic. | |
490 | */ | |
18730411 GT |
491 | static void pstore_register_kmsg(void) |
492 | { | |
493 | kmsg_dump_register(&pstore_dumper); | |
494 | } | |
495 | ||
ee1d2674 GT |
496 | static void pstore_unregister_kmsg(void) |
497 | { | |
498 | kmsg_dump_unregister(&pstore_dumper); | |
499 | } | |
500 | ||
f29e5956 AV |
501 | #ifdef CONFIG_PSTORE_CONSOLE |
502 | static void pstore_console_write(struct console *con, const char *s, unsigned c) | |
503 | { | |
b77fa617 | 504 | struct pstore_record record; |
f29e5956 | 505 | |
4c6c4d34 YH |
506 | if (!c) |
507 | return; | |
508 | ||
b77fa617 KC |
509 | pstore_record_init(&record, psinfo); |
510 | record.type = PSTORE_TYPE_CONSOLE; | |
80c9d03c | 511 | |
b77fa617 KC |
512 | record.buf = (char *)s; |
513 | record.size = c; | |
514 | psinfo->write(&record); | |
f29e5956 AV |
515 | } |
516 | ||
517 | static struct console pstore_console = { | |
f29e5956 | 518 | .write = pstore_console_write, |
f29e5956 AV |
519 | .index = -1, |
520 | }; | |
521 | ||
522 | static void pstore_register_console(void) | |
523 | { | |
d195c390 KC |
524 | /* Show which backend is going to get console writes. */ |
525 | strscpy(pstore_console.name, psinfo->name, | |
526 | sizeof(pstore_console.name)); | |
b7753fc7 KC |
527 | /* |
528 | * Always initialize flags here since prior unregister_console() | |
529 | * calls may have changed settings (specifically CON_ENABLED). | |
530 | */ | |
531 | pstore_console.flags = CON_PRINTBUFFER | CON_ENABLED | CON_ANYTIME; | |
f29e5956 AV |
532 | register_console(&pstore_console); |
533 | } | |
ee1d2674 GT |
534 | |
535 | static void pstore_unregister_console(void) | |
536 | { | |
537 | unregister_console(&pstore_console); | |
538 | } | |
f29e5956 AV |
539 | #else |
540 | static void pstore_register_console(void) {} | |
ee1d2674 | 541 | static void pstore_unregister_console(void) {} |
f29e5956 AV |
542 | #endif |
543 | ||
4c9ec219 KC |
544 | static int pstore_write_user_compat(struct pstore_record *record, |
545 | const char __user *buf) | |
5bf6d1b9 | 546 | { |
30800d99 KC |
547 | int ret = 0; |
548 | ||
549 | if (record->buf) | |
550 | return -EINVAL; | |
551 | ||
077090af | 552 | record->buf = memdup_user(buf, record->size); |
dfd6fa39 | 553 | if (IS_ERR(record->buf)) { |
077090af | 554 | ret = PTR_ERR(record->buf); |
30800d99 | 555 | goto out; |
5bf6d1b9 | 556 | } |
30800d99 KC |
557 | |
558 | ret = record->psi->write(record); | |
559 | ||
30800d99 | 560 | kfree(record->buf); |
077090af | 561 | out: |
30800d99 KC |
562 | record->buf = NULL; |
563 | ||
564 | return unlikely(ret < 0) ? ret : record->size; | |
5bf6d1b9 MS |
565 | } |
566 | ||
ca01d6dd TL |
567 | /* |
568 | * platform specific persistent storage driver registers with | |
569 | * us here. If pstore is already mounted, call the platform | |
570 | * read function right away to populate the file system. If not | |
571 | * then the pstore mount code will call us later to fill out | |
572 | * the file system. | |
ca01d6dd TL |
573 | */ |
574 | int pstore_register(struct pstore_info *psi) | |
575 | { | |
0d7cd09a | 576 | if (backend && strcmp(backend, psi->name)) { |
d85644dc GP |
577 | pr_warn("backend '%s' already in use: ignoring '%s'\n", |
578 | backend, psi->name); | |
579 | return -EBUSY; | |
0d7cd09a | 580 | } |
8e48b1a8 | 581 | |
4c9ec219 KC |
582 | /* Sanity check flags. */ |
583 | if (!psi->flags) { | |
584 | pr_warn("backend '%s' must support at least one frontend\n", | |
585 | psi->name); | |
586 | return -EINVAL; | |
587 | } | |
588 | ||
589 | /* Check for required functions. */ | |
590 | if (!psi->read || !psi->write) { | |
591 | pr_warn("backend '%s' must implement read() and write()\n", | |
592 | psi->name); | |
593 | return -EINVAL; | |
594 | } | |
595 | ||
cab12fd0 | 596 | mutex_lock(&psinfo_lock); |
ca01d6dd | 597 | if (psinfo) { |
0d7cd09a KC |
598 | pr_warn("backend '%s' already loaded: ignoring '%s'\n", |
599 | psinfo->name, psi->name); | |
cab12fd0 | 600 | mutex_unlock(&psinfo_lock); |
ca01d6dd TL |
601 | return -EBUSY; |
602 | } | |
dee28e72 | 603 | |
4c9ec219 KC |
604 | if (!psi->write_user) |
605 | psi->write_user = pstore_write_user_compat; | |
ca01d6dd | 606 | psinfo = psi; |
f6f82851 | 607 | mutex_init(&psinfo->read_mutex); |
8126b1c7 | 608 | spin_lock_init(&psinfo->buf_lock); |
ca01d6dd | 609 | |
8880fa32 KC |
610 | if (psi->flags & PSTORE_FLAGS_DMESG) |
611 | allocate_buf_for_compression(); | |
b0aad7a9 | 612 | |
27e5041a | 613 | pstore_get_records(0); |
ca01d6dd | 614 | |
3524e688 PT |
615 | if (psi->flags & PSTORE_FLAGS_DMESG) { |
616 | pstore_dumper.max_reason = psinfo->max_reason; | |
c950fd6f | 617 | pstore_register_kmsg(); |
3524e688 | 618 | } |
c950fd6f | 619 | if (psi->flags & PSTORE_FLAGS_CONSOLE) |
df36ac1b | 620 | pstore_register_console(); |
c950fd6f | 621 | if (psi->flags & PSTORE_FLAGS_FTRACE) |
df36ac1b | 622 | pstore_register_ftrace(); |
c950fd6f | 623 | if (psi->flags & PSTORE_FLAGS_PMSG) |
9d5438f4 | 624 | pstore_register_pmsg(); |
ca01d6dd | 625 | |
6330d553 | 626 | /* Start watching for new records, if desired. */ |
78c83c82 | 627 | pstore_timer_kick(); |
6dda9266 | 628 | |
42222c2a WL |
629 | /* |
630 | * Update the module parameter backend, so it is visible | |
631 | * through /sys/module/pstore/parameters/backend | |
632 | */ | |
563ca40d | 633 | backend = kstrdup(psi->name, GFP_KERNEL); |
42222c2a | 634 | |
ef748853 | 635 | pr_info("Registered %s as persistent store backend\n", psi->name); |
8e48b1a8 | 636 | |
6248a066 | 637 | mutex_unlock(&psinfo_lock); |
ca01d6dd TL |
638 | return 0; |
639 | } | |
640 | EXPORT_SYMBOL_GPL(pstore_register); | |
641 | ||
ee1d2674 GT |
642 | void pstore_unregister(struct pstore_info *psi) |
643 | { | |
6248a066 KC |
644 | /* It's okay to unregister nothing. */ |
645 | if (!psi) | |
646 | return; | |
647 | ||
648 | mutex_lock(&psinfo_lock); | |
649 | ||
650 | /* Only one backend can be registered at a time. */ | |
651 | if (WARN_ON(psi != psinfo)) { | |
652 | mutex_unlock(&psinfo_lock); | |
653 | return; | |
654 | } | |
655 | ||
78c83c82 | 656 | /* Unregister all callbacks. */ |
c950fd6f | 657 | if (psi->flags & PSTORE_FLAGS_PMSG) |
a1db8060 | 658 | pstore_unregister_pmsg(); |
c950fd6f | 659 | if (psi->flags & PSTORE_FLAGS_FTRACE) |
a1db8060 | 660 | pstore_unregister_ftrace(); |
c950fd6f | 661 | if (psi->flags & PSTORE_FLAGS_CONSOLE) |
a1db8060 | 662 | pstore_unregister_console(); |
c950fd6f NK |
663 | if (psi->flags & PSTORE_FLAGS_DMESG) |
664 | pstore_unregister_kmsg(); | |
ee1d2674 | 665 | |
78c83c82 KC |
666 | /* Stop timer and make sure all work has finished. */ |
667 | del_timer_sync(&pstore_timer); | |
668 | flush_work(&pstore_work); | |
669 | ||
609e28bb KC |
670 | /* Remove all backend records from filesystem tree. */ |
671 | pstore_put_backend_records(psi); | |
672 | ||
ee1d2674 GT |
673 | free_buf_for_compression(); |
674 | ||
675 | psinfo = NULL; | |
563ca40d | 676 | kfree(backend); |
ee1d2674 | 677 | backend = NULL; |
6a14f198 GP |
678 | |
679 | pr_info("Unregistered %s as persistent store backend\n", psi->name); | |
6248a066 | 680 | mutex_unlock(&psinfo_lock); |
ee1d2674 GT |
681 | } |
682 | EXPORT_SYMBOL_GPL(pstore_unregister); | |
683 | ||
634f8f51 KC |
684 | static void decompress_record(struct pstore_record *record) |
685 | { | |
bdabc8e7 | 686 | int ret; |
634f8f51 | 687 | int unzipped_len; |
bdabc8e7 | 688 | char *unzipped, *workspace; |
634f8f51 | 689 | |
19d8e914 | 690 | if (!IS_ENABLED(CONFIG_PSTORE_COMPRESS) || !record->compressed) |
4a16d1cb AK |
691 | return; |
692 | ||
634f8f51 | 693 | /* Only PSTORE_TYPE_DMESG support compression. */ |
4a16d1cb | 694 | if (record->type != PSTORE_TYPE_DMESG) { |
634f8f51 KC |
695 | pr_warn("ignored compressed record type %d\n", record->type); |
696 | return; | |
697 | } | |
698 | ||
bdabc8e7 | 699 | /* Missing compression buffer means compression was not initialized. */ |
634f8f51 | 700 | if (!big_oops_buf) { |
bdabc8e7 | 701 | pr_warn("no decompression method initialized!\n"); |
634f8f51 KC |
702 | return; |
703 | } | |
704 | ||
bdabc8e7 KC |
705 | /* Allocate enough space to hold max decompression and ECC. */ |
706 | unzipped_len = big_oops_buf_sz; | |
707 | workspace = kmalloc(unzipped_len + record->ecc_notice_size, | |
708 | GFP_KERNEL); | |
709 | if (!workspace) | |
7e8cc8dc | 710 | return; |
7e8cc8dc | 711 | |
bdabc8e7 | 712 | /* After decompression "unzipped_len" is almost certainly smaller. */ |
40158dbf GP |
713 | ret = crypto_comp_decompress(tfm, record->buf, record->size, |
714 | workspace, &unzipped_len); | |
bdabc8e7 | 715 | if (ret) { |
40158dbf | 716 | pr_err("crypto_comp_decompress failed, ret = %d!\n", ret); |
bdabc8e7 | 717 | kfree(workspace); |
7e8cc8dc KC |
718 | return; |
719 | } | |
7e8cc8dc KC |
720 | |
721 | /* Append ECC notice to decompressed buffer. */ | |
bdabc8e7 | 722 | memcpy(workspace + unzipped_len, record->buf + record->size, |
7e8cc8dc KC |
723 | record->ecc_notice_size); |
724 | ||
bdabc8e7 KC |
725 | /* Copy decompressed contents into an minimum-sized allocation. */ |
726 | unzipped = kmemdup(workspace, unzipped_len + record->ecc_notice_size, | |
727 | GFP_KERNEL); | |
728 | kfree(workspace); | |
729 | if (!unzipped) | |
730 | return; | |
731 | ||
732 | /* Swap out compressed contents with decompressed contents. */ | |
7e8cc8dc | 733 | kfree(record->buf); |
bdabc8e7 | 734 | record->buf = unzipped; |
7e8cc8dc KC |
735 | record->size = unzipped_len; |
736 | record->compressed = false; | |
634f8f51 KC |
737 | } |
738 | ||
ca01d6dd | 739 | /* |
3a7d2fd1 | 740 | * Read all the records from one persistent store backend. Create |
6dda9266 LT |
741 | * files in our filesystem. Don't warn about -EEXIST errors |
742 | * when we are re-scanning the backing store looking to add new | |
743 | * error records. | |
ca01d6dd | 744 | */ |
3a7d2fd1 KC |
745 | void pstore_get_backend_records(struct pstore_info *psi, |
746 | struct dentry *root, int quiet) | |
ca01d6dd | 747 | { |
2a2b0acf | 748 | int failed = 0; |
656de42e | 749 | unsigned int stop_loop = 65536; |
ca01d6dd | 750 | |
3a7d2fd1 | 751 | if (!psi || !root) |
ca01d6dd TL |
752 | return; |
753 | ||
f6f82851 | 754 | mutex_lock(&psi->read_mutex); |
2174f6df | 755 | if (psi->open && psi->open(psi)) |
06cf91b4 CG |
756 | goto out; |
757 | ||
1dfff7dd KC |
758 | /* |
759 | * Backend callback read() allocates record.buf. decompress_record() | |
760 | * may reallocate record.buf. On success, pstore_mkfile() will keep | |
761 | * the record.buf, so free it only on failure. | |
762 | */ | |
656de42e | 763 | for (; stop_loop; stop_loop--) { |
2a2b0acf KC |
764 | struct pstore_record *record; |
765 | int rc; | |
766 | ||
767 | record = kzalloc(sizeof(*record), GFP_KERNEL); | |
768 | if (!record) { | |
769 | pr_err("out of memory creating record\n"); | |
770 | break; | |
771 | } | |
e581ca81 | 772 | pstore_record_init(record, psi); |
2a2b0acf KC |
773 | |
774 | record->size = psi->read(record); | |
775 | ||
776 | /* No more records left in backend? */ | |
f6525b96 DA |
777 | if (record->size <= 0) { |
778 | kfree(record); | |
2a2b0acf | 779 | break; |
f6525b96 | 780 | } |
2a2b0acf KC |
781 | |
782 | decompress_record(record); | |
3a7d2fd1 | 783 | rc = pstore_mkfile(root, record); |
1dfff7dd | 784 | if (rc) { |
83f70f07 | 785 | /* pstore_mkfile() did not take record, so free it. */ |
2a2b0acf | 786 | kfree(record->buf); |
8ca869b2 | 787 | kfree(record->priv); |
83f70f07 | 788 | kfree(record); |
1dfff7dd KC |
789 | if (rc != -EEXIST || !quiet) |
790 | failed++; | |
791 | } | |
ca01d6dd | 792 | } |
2174f6df KC |
793 | if (psi->close) |
794 | psi->close(psi); | |
06cf91b4 | 795 | out: |
f6f82851 | 796 | mutex_unlock(&psi->read_mutex); |
ca01d6dd TL |
797 | |
798 | if (failed) | |
656de42e | 799 | pr_warn("failed to create %d record(s) from '%s'\n", |
ef748853 | 800 | failed, psi->name); |
656de42e KC |
801 | if (!stop_loop) |
802 | pr_err("looping? Too many records seen from '%s'\n", | |
803 | psi->name); | |
ca01d6dd TL |
804 | } |
805 | ||
6dda9266 LT |
806 | static void pstore_dowork(struct work_struct *work) |
807 | { | |
808 | pstore_get_records(1); | |
809 | } | |
810 | ||
24ed960a | 811 | static void pstore_timefunc(struct timer_list *unused) |
6dda9266 LT |
812 | { |
813 | if (pstore_new_entry) { | |
814 | pstore_new_entry = 0; | |
815 | schedule_work(&pstore_work); | |
816 | } | |
817 | ||
78c83c82 | 818 | pstore_timer_kick(); |
6dda9266 LT |
819 | } |
820 | ||
8d82cee2 | 821 | static void __init pstore_choose_compression(void) |
fe1d4758 KC |
822 | { |
823 | const struct pstore_zbackend *step; | |
824 | ||
825 | if (!compress) | |
826 | return; | |
827 | ||
828 | for (step = zbackends; step->name; step++) { | |
829 | if (!strcmp(compress, step->name)) { | |
830 | zbackend = step; | |
fe1d4758 KC |
831 | return; |
832 | } | |
833 | } | |
834 | } | |
835 | ||
cb095afd KC |
836 | static int __init pstore_init(void) |
837 | { | |
838 | int ret; | |
839 | ||
840 | pstore_choose_compression(); | |
841 | ||
41603165 JFG |
842 | /* |
843 | * Check if any pstore backends registered earlier but did not | |
844 | * initialize compression because crypto was not ready. If so, | |
845 | * initialize compression now. | |
846 | */ | |
95047b05 | 847 | allocate_buf_for_compression(); |
41603165 | 848 | |
cb095afd KC |
849 | ret = pstore_init_fs(); |
850 | if (ret) | |
8a57d6d4 | 851 | free_buf_for_compression(); |
cb095afd | 852 | |
8a57d6d4 | 853 | return ret; |
cb095afd | 854 | } |
41603165 | 855 | late_initcall(pstore_init); |
cb095afd KC |
856 | |
857 | static void __exit pstore_exit(void) | |
858 | { | |
859 | pstore_exit_fs(); | |
860 | } | |
861 | module_exit(pstore_exit) | |
862 | ||
cb095afd KC |
863 | MODULE_AUTHOR("Tony Luck <tony.luck@intel.com>"); |
864 | MODULE_LICENSE("GPL"); |