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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> |
e4f0a7ec | 31 | #include <linux/scatterlist.h> |
ca01d6dd TL |
32 | #include <linux/slab.h> |
33 | #include <linux/uaccess.h> | |
a3f5f075 | 34 | #include <linux/jiffies.h> |
6dda9266 | 35 | #include <linux/workqueue.h> |
ca01d6dd | 36 | |
e4f0a7ec AB |
37 | #include <crypto/acompress.h> |
38 | ||
ca01d6dd TL |
39 | #include "internal.h" |
40 | ||
6dda9266 TL |
41 | /* |
42 | * We defer making "oops" entries appear in pstore - see | |
43 | * whether the system is actually still running well enough | |
44 | * to let someone see the entry | |
45 | */ | |
521f7288 | 46 | static int pstore_update_ms = -1; |
a3f5f075 AV |
47 | module_param_named(update_ms, pstore_update_ms, int, 0600); |
48 | MODULE_PARM_DESC(update_ms, "milliseconds before pstore updates its content " | |
521f7288 | 49 | "(default is -1, which means runtime updates are disabled; " |
78c83c82 | 50 | "enabling this option may not be safe; it may lead to further " |
521f7288 | 51 | "corruption on Oopses)"); |
6dda9266 | 52 | |
f0f23e54 JFG |
53 | /* Names should be in the same order as the enum pstore_type_id */ |
54 | static const char * const pstore_type_names[] = { | |
55 | "dmesg", | |
56 | "mce", | |
57 | "console", | |
58 | "ftrace", | |
59 | "rtas", | |
60 | "powerpc-ofw", | |
61 | "powerpc-common", | |
62 | "pmsg", | |
63 | "powerpc-opal", | |
64 | }; | |
65 | ||
6dda9266 TL |
66 | static int pstore_new_entry; |
67 | ||
24ed960a | 68 | static void pstore_timefunc(struct timer_list *); |
1d27e3e2 | 69 | static DEFINE_TIMER(pstore_timer, pstore_timefunc); |
6dda9266 TL |
70 | |
71 | static void pstore_dowork(struct work_struct *); | |
72 | static DECLARE_WORK(pstore_work, pstore_dowork); | |
73 | ||
ca01d6dd | 74 | /* |
6248a066 KC |
75 | * psinfo_lock protects "psinfo" during calls to |
76 | * pstore_register(), pstore_unregister(), and | |
77 | * the filesystem mount/unmount routines. | |
ca01d6dd | 78 | */ |
cab12fd0 | 79 | static DEFINE_MUTEX(psinfo_lock); |
060287b8 | 80 | struct pstore_info *psinfo; |
ca01d6dd | 81 | |
dee28e72 | 82 | static char *backend; |
d973f7d8 KC |
83 | module_param(backend, charp, 0444); |
84 | MODULE_PARM_DESC(backend, "specific backend to use"); | |
85 | ||
fe1d4758 KC |
86 | static char *compress = |
87 | #ifdef CONFIG_PSTORE_COMPRESS_DEFAULT | |
88 | CONFIG_PSTORE_COMPRESS_DEFAULT; | |
89 | #else | |
90 | NULL; | |
91 | #endif | |
d973f7d8 KC |
92 | module_param(compress, charp, 0444); |
93 | MODULE_PARM_DESC(compress, "compression to use"); | |
dee28e72 | 94 | |
b0aad7a9 | 95 | /* Compression parameters */ |
e4f0a7ec AB |
96 | static struct crypto_acomp *tfm; |
97 | static struct acomp_req *creq; | |
8cfc8ddc GT |
98 | |
99 | struct pstore_zbackend { | |
cb3bee03 | 100 | int (*zbufsize)(size_t size); |
8cfc8ddc GT |
101 | const char *name; |
102 | }; | |
b0aad7a9 AB |
103 | |
104 | static char *big_oops_buf; | |
105 | static size_t big_oops_buf_sz; | |
106 | ||
366f7e7a | 107 | /* How much of the console log to snapshot */ |
26fecbf7 | 108 | unsigned long kmsg_bytes = CONFIG_PSTORE_DEFAULT_KMSG_BYTES; |
ca01d6dd | 109 | |
366f7e7a | 110 | void pstore_set_kmsg_bytes(int bytes) |
ca01d6dd | 111 | { |
366f7e7a | 112 | kmsg_bytes = bytes; |
ca01d6dd TL |
113 | } |
114 | ||
ca01d6dd TL |
115 | /* Tag each group of saved records with a sequence number */ |
116 | static int oopscount; | |
117 | ||
f0f23e54 JFG |
118 | const char *pstore_type_to_name(enum pstore_type_id type) |
119 | { | |
120 | BUILD_BUG_ON(ARRAY_SIZE(pstore_type_names) != PSTORE_TYPE_MAX); | |
121 | ||
122 | if (WARN_ON_ONCE(type >= PSTORE_TYPE_MAX)) | |
123 | return "unknown"; | |
124 | ||
125 | return pstore_type_names[type]; | |
126 | } | |
127 | EXPORT_SYMBOL_GPL(pstore_type_to_name); | |
128 | ||
129 | enum pstore_type_id pstore_name_to_type(const char *name) | |
130 | { | |
131 | int i; | |
132 | ||
133 | for (i = 0; i < PSTORE_TYPE_MAX; i++) { | |
134 | if (!strcmp(pstore_type_names[i], name)) | |
135 | return i; | |
136 | } | |
137 | ||
138 | return PSTORE_TYPE_MAX; | |
139 | } | |
140 | EXPORT_SYMBOL_GPL(pstore_name_to_type); | |
141 | ||
78c83c82 KC |
142 | static void pstore_timer_kick(void) |
143 | { | |
144 | if (pstore_update_ms < 0) | |
145 | return; | |
146 | ||
147 | mod_timer(&pstore_timer, jiffies + msecs_to_jiffies(pstore_update_ms)); | |
148 | } | |
149 | ||
8126b1c7 | 150 | static bool pstore_cannot_block_path(enum kmsg_dump_reason reason) |
9f244e9c | 151 | { |
8126b1c7 JH |
152 | /* |
153 | * In case of NMI path, pstore shouldn't be blocked | |
154 | * regardless of reason. | |
155 | */ | |
9f244e9c SA |
156 | if (in_nmi()) |
157 | return true; | |
158 | ||
159 | switch (reason) { | |
160 | /* In panic case, other cpus are stopped by smp_send_stop(). */ | |
161 | case KMSG_DUMP_PANIC: | |
8126b1c7 JH |
162 | /* |
163 | * Emergency restart shouldn't be blocked by spinning on | |
164 | * pstore_info::buf_lock. | |
165 | */ | |
9f244e9c SA |
166 | case KMSG_DUMP_EMERG: |
167 | return true; | |
168 | default: | |
169 | return false; | |
170 | } | |
171 | } | |
9f244e9c | 172 | |
58eb5b67 | 173 | #if IS_ENABLED(CONFIG_PSTORE_DEFLATE_COMPRESS) |
cb3bee03 | 174 | static int zbufsize_deflate(size_t size) |
adb42f5e | 175 | { |
7de8fe2f AB |
176 | size_t cmpr; |
177 | ||
cb3bee03 | 178 | switch (size) { |
7de8fe2f AB |
179 | /* buffer range for efivars */ |
180 | case 1000 ... 2000: | |
181 | cmpr = 56; | |
182 | break; | |
183 | case 2001 ... 3000: | |
184 | cmpr = 54; | |
185 | break; | |
186 | case 3001 ... 3999: | |
187 | cmpr = 52; | |
188 | break; | |
189 | /* buffer range for nvram, erst */ | |
190 | case 4000 ... 10000: | |
191 | cmpr = 45; | |
192 | break; | |
193 | default: | |
194 | cmpr = 60; | |
195 | break; | |
196 | } | |
b0aad7a9 | 197 | |
cb3bee03 | 198 | return (size * 100) / cmpr; |
8cfc8ddc | 199 | } |
8cfc8ddc GT |
200 | #endif |
201 | ||
58eb5b67 | 202 | #if IS_ENABLED(CONFIG_PSTORE_LZO_COMPRESS) |
cb3bee03 | 203 | static int zbufsize_lzo(size_t size) |
8cfc8ddc | 204 | { |
cb3bee03 | 205 | return lzo1x_worst_compress(size); |
8cfc8ddc | 206 | } |
8cfc8ddc GT |
207 | #endif |
208 | ||
58eb5b67 | 209 | #if IS_ENABLED(CONFIG_PSTORE_LZ4_COMPRESS) || IS_ENABLED(CONFIG_PSTORE_LZ4HC_COMPRESS) |
cb3bee03 | 210 | static int zbufsize_lz4(size_t size) |
8cfc8ddc | 211 | { |
cb3bee03 | 212 | return LZ4_compressBound(size); |
8cfc8ddc | 213 | } |
239b7161 GT |
214 | #endif |
215 | ||
58eb5b67 | 216 | #if IS_ENABLED(CONFIG_PSTORE_842_COMPRESS) |
cb3bee03 | 217 | static int zbufsize_842(size_t size) |
239b7161 | 218 | { |
55597406 | 219 | return size; |
239b7161 | 220 | } |
8cfc8ddc GT |
221 | #endif |
222 | ||
1021bcf4 GT |
223 | #if IS_ENABLED(CONFIG_PSTORE_ZSTD_COMPRESS) |
224 | static int zbufsize_zstd(size_t size) | |
225 | { | |
cf30f6a5 | 226 | return zstd_compress_bound(size); |
1021bcf4 GT |
227 | } |
228 | #endif | |
229 | ||
fe1d4758 KC |
230 | static const struct pstore_zbackend *zbackend __ro_after_init; |
231 | ||
232 | static const struct pstore_zbackend zbackends[] = { | |
58eb5b67 | 233 | #if IS_ENABLED(CONFIG_PSTORE_DEFLATE_COMPRESS) |
fe1d4758 | 234 | { |
cb3bee03 GT |
235 | .zbufsize = zbufsize_deflate, |
236 | .name = "deflate", | |
fe1d4758 KC |
237 | }, |
238 | #endif | |
58eb5b67 | 239 | #if IS_ENABLED(CONFIG_PSTORE_LZO_COMPRESS) |
fe1d4758 | 240 | { |
cb3bee03 | 241 | .zbufsize = zbufsize_lzo, |
fe1d4758 KC |
242 | .name = "lzo", |
243 | }, | |
244 | #endif | |
58eb5b67 | 245 | #if IS_ENABLED(CONFIG_PSTORE_LZ4_COMPRESS) |
fe1d4758 | 246 | { |
cb3bee03 | 247 | .zbufsize = zbufsize_lz4, |
fe1d4758 KC |
248 | .name = "lz4", |
249 | }, | |
250 | #endif | |
58eb5b67 | 251 | #if IS_ENABLED(CONFIG_PSTORE_LZ4HC_COMPRESS) |
fe1d4758 | 252 | { |
cb3bee03 | 253 | .zbufsize = zbufsize_lz4, |
fe1d4758 KC |
254 | .name = "lz4hc", |
255 | }, | |
8cfc8ddc | 256 | #endif |
58eb5b67 | 257 | #if IS_ENABLED(CONFIG_PSTORE_842_COMPRESS) |
fe1d4758 | 258 | { |
cb3bee03 | 259 | .zbufsize = zbufsize_842, |
fe1d4758 KC |
260 | .name = "842", |
261 | }, | |
1021bcf4 GT |
262 | #endif |
263 | #if IS_ENABLED(CONFIG_PSTORE_ZSTD_COMPRESS) | |
264 | { | |
265 | .zbufsize = zbufsize_zstd, | |
266 | .name = "zstd", | |
267 | }, | |
fe1d4758 KC |
268 | #endif |
269 | { } | |
270 | }; | |
8cfc8ddc GT |
271 | |
272 | static int pstore_compress(const void *in, void *out, | |
cb3bee03 | 273 | unsigned int inlen, unsigned int outlen) |
8cfc8ddc | 274 | { |
e4f0a7ec | 275 | struct scatterlist src, dst; |
cb3bee03 GT |
276 | int ret; |
277 | ||
19d8e914 | 278 | if (!IS_ENABLED(CONFIG_PSTORE_COMPRESS)) |
fd49e032 MC |
279 | return -EINVAL; |
280 | ||
e4f0a7ec AB |
281 | sg_init_table(&src, 1); |
282 | sg_set_buf(&src, in, inlen); | |
283 | ||
284 | sg_init_table(&dst, 1); | |
285 | sg_set_buf(&dst, out, outlen); | |
286 | ||
287 | acomp_request_set_params(creq, &src, &dst, inlen, outlen); | |
288 | ||
289 | ret = crypto_acomp_compress(creq); | |
cb3bee03 GT |
290 | if (ret) { |
291 | pr_err("crypto_comp_compress failed, ret = %d!\n", ret); | |
292 | return ret; | |
293 | } | |
294 | ||
295 | return outlen; | |
8cfc8ddc GT |
296 | } |
297 | ||
8cfc8ddc GT |
298 | static void allocate_buf_for_compression(void) |
299 | { | |
e4f0a7ec | 300 | struct crypto_acomp *acomp; |
95047b05 KC |
301 | int size; |
302 | char *buf; | |
303 | ||
304 | /* Skip if not built-in or compression backend not selected yet. */ | |
e698aaf3 | 305 | if (!IS_ENABLED(CONFIG_PSTORE_COMPRESS) || !zbackend) |
cb3bee03 GT |
306 | return; |
307 | ||
95047b05 KC |
308 | /* Skip if no pstore backend yet or compression init already done. */ |
309 | if (!psinfo || tfm) | |
310 | return; | |
311 | ||
e4f0a7ec | 312 | if (!crypto_has_acomp(zbackend->name, 0, CRYPTO_ALG_ASYNC)) { |
95047b05 | 313 | pr_err("Unknown compression: %s\n", zbackend->name); |
cb3bee03 GT |
314 | return; |
315 | } | |
316 | ||
95047b05 KC |
317 | size = zbackend->zbufsize(psinfo->bufsize); |
318 | if (size <= 0) { | |
319 | pr_err("Invalid compression size for %s: %d\n", | |
320 | zbackend->name, size); | |
cb3bee03 | 321 | return; |
95047b05 | 322 | } |
cb3bee03 | 323 | |
95047b05 KC |
324 | buf = kmalloc(size, GFP_KERNEL); |
325 | if (!buf) { | |
326 | pr_err("Failed %d byte compression buffer allocation for: %s\n", | |
327 | size, zbackend->name); | |
cb3bee03 GT |
328 | return; |
329 | } | |
330 | ||
e4f0a7ec AB |
331 | acomp = crypto_alloc_acomp(zbackend->name, 0, CRYPTO_ALG_ASYNC); |
332 | if (IS_ERR_OR_NULL(acomp)) { | |
95047b05 KC |
333 | kfree(buf); |
334 | pr_err("crypto_alloc_comp('%s') failed: %ld\n", zbackend->name, | |
e4f0a7ec AB |
335 | PTR_ERR(acomp)); |
336 | return; | |
337 | } | |
338 | ||
339 | creq = acomp_request_alloc(acomp); | |
340 | if (!creq) { | |
341 | crypto_free_acomp(acomp); | |
342 | kfree(buf); | |
343 | pr_err("acomp_request_alloc('%s') failed\n", zbackend->name); | |
cb3bee03 | 344 | return; |
8cfc8ddc | 345 | } |
95047b05 KC |
346 | |
347 | /* A non-NULL big_oops_buf indicates compression is available. */ | |
e4f0a7ec | 348 | tfm = acomp; |
95047b05 KC |
349 | big_oops_buf_sz = size; |
350 | big_oops_buf = buf; | |
351 | ||
0eed84ff | 352 | pr_info("Using crash dump compression: %s\n", zbackend->name); |
8cfc8ddc GT |
353 | } |
354 | ||
355 | static void free_buf_for_compression(void) | |
356 | { | |
a9fb94a9 | 357 | if (IS_ENABLED(CONFIG_PSTORE_COMPRESS) && tfm) { |
e4f0a7ec AB |
358 | acomp_request_free(creq); |
359 | crypto_free_acomp(tfm); | |
a9fb94a9 PHS |
360 | tfm = NULL; |
361 | } | |
cb3bee03 GT |
362 | kfree(big_oops_buf); |
363 | big_oops_buf = NULL; | |
364 | big_oops_buf_sz = 0; | |
ee1d2674 GT |
365 | } |
366 | ||
b0aad7a9 AB |
367 | /* |
368 | * Called when compression fails, since the printk buffer | |
369 | * would be fetched for compression calling it again when | |
370 | * compression fails would have moved the iterator of | |
371 | * printk buffer which results in fetching old contents. | |
372 | * Copy the recent messages from big_oops_buf to psinfo->buf | |
373 | */ | |
374 | static size_t copy_kmsg_to_buffer(int hsize, size_t len) | |
375 | { | |
376 | size_t total_len; | |
377 | size_t diff; | |
378 | ||
379 | total_len = hsize + len; | |
380 | ||
381 | if (total_len > psinfo->bufsize) { | |
382 | diff = total_len - psinfo->bufsize + hsize; | |
383 | memcpy(psinfo->buf, big_oops_buf, hsize); | |
384 | memcpy(psinfo->buf + hsize, big_oops_buf + diff, | |
385 | psinfo->bufsize - hsize); | |
386 | total_len = psinfo->bufsize; | |
387 | } else | |
388 | memcpy(psinfo->buf, big_oops_buf, total_len); | |
389 | ||
390 | return total_len; | |
391 | } | |
392 | ||
e581ca81 KC |
393 | void pstore_record_init(struct pstore_record *record, |
394 | struct pstore_info *psinfo) | |
395 | { | |
396 | memset(record, 0, sizeof(*record)); | |
397 | ||
398 | record->psi = psinfo; | |
c7f3c595 KC |
399 | |
400 | /* Report zeroed timestamp if called before timekeeping has resumed. */ | |
7aaa822e | 401 | record->time = ns_to_timespec64(ktime_get_real_fast_ns()); |
e581ca81 KC |
402 | } |
403 | ||
ca01d6dd | 404 | /* |
0eed84ff KC |
405 | * callback from kmsg_dump. Save as much as we can (up to kmsg_bytes) from the |
406 | * end of the buffer. | |
ca01d6dd TL |
407 | */ |
408 | static void pstore_dump(struct kmsg_dumper *dumper, | |
e2ae715d | 409 | enum kmsg_dump_reason reason) |
ca01d6dd | 410 | { |
f9f3f02d | 411 | struct kmsg_dump_iter iter; |
e2ae715d | 412 | unsigned long total = 0; |
381b872c | 413 | const char *why; |
b94fdd07 | 414 | unsigned int part = 1; |
8126b1c7 | 415 | unsigned long flags = 0; |
e2ae715d | 416 | int ret; |
ca01d6dd | 417 | |
fb13cb8a | 418 | why = kmsg_dump_reason_str(reason); |
9f6af27f | 419 | |
8126b1c7 JH |
420 | if (pstore_cannot_block_path(reason)) { |
421 | if (!spin_trylock_irqsave(&psinfo->buf_lock, flags)) { | |
422 | pr_err("dump skipped in %s path because of concurrent dump\n", | |
423 | in_nmi() ? "NMI" : why); | |
959217c8 | 424 | return; |
9f244e9c | 425 | } |
8126b1c7 JH |
426 | } else { |
427 | spin_lock_irqsave(&psinfo->buf_lock, flags); | |
98e44fda | 428 | } |
ea84b580 | 429 | |
f9f3f02d JO |
430 | kmsg_dump_rewind(&iter); |
431 | ||
ca01d6dd TL |
432 | oopscount++; |
433 | while (total < kmsg_bytes) { | |
e2ae715d | 434 | char *dst; |
76cc9580 KC |
435 | size_t dst_size; |
436 | int header_size; | |
b0aad7a9 | 437 | int zipped_len = -1; |
76cc9580 | 438 | size_t dump_size; |
e581ca81 KC |
439 | struct pstore_record record; |
440 | ||
441 | pstore_record_init(&record, psinfo); | |
442 | record.type = PSTORE_TYPE_DMESG; | |
443 | record.count = oopscount; | |
444 | record.reason = reason; | |
445 | record.part = part; | |
446 | record.buf = psinfo->buf; | |
e2ae715d | 447 | |
ea84b580 | 448 | if (big_oops_buf) { |
b0aad7a9 | 449 | dst = big_oops_buf; |
76cc9580 | 450 | dst_size = big_oops_buf_sz; |
235f6d15 NK |
451 | } else { |
452 | dst = psinfo->buf; | |
76cc9580 | 453 | dst_size = psinfo->bufsize; |
235f6d15 NK |
454 | } |
455 | ||
76cc9580 KC |
456 | /* Write dump header. */ |
457 | header_size = snprintf(dst, dst_size, "%s#%d Part%u\n", why, | |
458 | oopscount, part); | |
459 | dst_size -= header_size; | |
ca01d6dd | 460 | |
76cc9580 | 461 | /* Write dump contents. */ |
f9f3f02d | 462 | if (!kmsg_dump_get_buffer(&iter, true, dst + header_size, |
76cc9580 | 463 | dst_size, &dump_size)) |
235f6d15 | 464 | break; |
b0aad7a9 | 465 | |
ea84b580 | 466 | if (big_oops_buf) { |
b0aad7a9 | 467 | zipped_len = pstore_compress(dst, psinfo->buf, |
76cc9580 KC |
468 | header_size + dump_size, |
469 | psinfo->bufsize); | |
b0aad7a9 AB |
470 | |
471 | if (zipped_len > 0) { | |
76cc9580 KC |
472 | record.compressed = true; |
473 | record.size = zipped_len; | |
b0aad7a9 | 474 | } else { |
76cc9580 KC |
475 | record.size = copy_kmsg_to_buffer(header_size, |
476 | dump_size); | |
b0aad7a9 AB |
477 | } |
478 | } else { | |
76cc9580 | 479 | record.size = header_size + dump_size; |
b0aad7a9 | 480 | } |
ca01d6dd | 481 | |
76cc9580 | 482 | ret = psinfo->write(&record); |
78c83c82 | 483 | if (ret == 0 && reason == KMSG_DUMP_OOPS) { |
6dda9266 | 484 | pstore_new_entry = 1; |
78c83c82 KC |
485 | pstore_timer_kick(); |
486 | } | |
e2ae715d | 487 | |
76cc9580 | 488 | total += record.size; |
56280682 | 489 | part++; |
ca01d6dd | 490 | } |
8126b1c7 | 491 | spin_unlock_irqrestore(&psinfo->buf_lock, flags); |
ca01d6dd TL |
492 | } |
493 | ||
494 | static struct kmsg_dumper pstore_dumper = { | |
495 | .dump = pstore_dump, | |
496 | }; | |
497 | ||
306e5c2a GT |
498 | /* |
499 | * Register with kmsg_dump to save last part of console log on panic. | |
500 | */ | |
18730411 GT |
501 | static void pstore_register_kmsg(void) |
502 | { | |
503 | kmsg_dump_register(&pstore_dumper); | |
504 | } | |
505 | ||
ee1d2674 GT |
506 | static void pstore_unregister_kmsg(void) |
507 | { | |
508 | kmsg_dump_unregister(&pstore_dumper); | |
509 | } | |
510 | ||
f29e5956 AV |
511 | #ifdef CONFIG_PSTORE_CONSOLE |
512 | static void pstore_console_write(struct console *con, const char *s, unsigned c) | |
513 | { | |
b77fa617 | 514 | struct pstore_record record; |
f29e5956 | 515 | |
4c6c4d34 YH |
516 | if (!c) |
517 | return; | |
518 | ||
b77fa617 KC |
519 | pstore_record_init(&record, psinfo); |
520 | record.type = PSTORE_TYPE_CONSOLE; | |
80c9d03c | 521 | |
b77fa617 KC |
522 | record.buf = (char *)s; |
523 | record.size = c; | |
524 | psinfo->write(&record); | |
f29e5956 AV |
525 | } |
526 | ||
527 | static struct console pstore_console = { | |
f29e5956 | 528 | .write = pstore_console_write, |
f29e5956 AV |
529 | .index = -1, |
530 | }; | |
531 | ||
532 | static void pstore_register_console(void) | |
533 | { | |
d195c390 KC |
534 | /* Show which backend is going to get console writes. */ |
535 | strscpy(pstore_console.name, psinfo->name, | |
536 | sizeof(pstore_console.name)); | |
b7753fc7 KC |
537 | /* |
538 | * Always initialize flags here since prior unregister_console() | |
539 | * calls may have changed settings (specifically CON_ENABLED). | |
540 | */ | |
541 | pstore_console.flags = CON_PRINTBUFFER | CON_ENABLED | CON_ANYTIME; | |
f29e5956 AV |
542 | register_console(&pstore_console); |
543 | } | |
ee1d2674 GT |
544 | |
545 | static void pstore_unregister_console(void) | |
546 | { | |
547 | unregister_console(&pstore_console); | |
548 | } | |
f29e5956 AV |
549 | #else |
550 | static void pstore_register_console(void) {} | |
ee1d2674 | 551 | static void pstore_unregister_console(void) {} |
f29e5956 AV |
552 | #endif |
553 | ||
4c9ec219 KC |
554 | static int pstore_write_user_compat(struct pstore_record *record, |
555 | const char __user *buf) | |
5bf6d1b9 | 556 | { |
30800d99 KC |
557 | int ret = 0; |
558 | ||
559 | if (record->buf) | |
560 | return -EINVAL; | |
561 | ||
077090af | 562 | record->buf = memdup_user(buf, record->size); |
dfd6fa39 | 563 | if (IS_ERR(record->buf)) { |
077090af | 564 | ret = PTR_ERR(record->buf); |
30800d99 | 565 | goto out; |
5bf6d1b9 | 566 | } |
30800d99 KC |
567 | |
568 | ret = record->psi->write(record); | |
569 | ||
30800d99 | 570 | kfree(record->buf); |
077090af | 571 | out: |
30800d99 KC |
572 | record->buf = NULL; |
573 | ||
574 | return unlikely(ret < 0) ? ret : record->size; | |
5bf6d1b9 MS |
575 | } |
576 | ||
ca01d6dd TL |
577 | /* |
578 | * platform specific persistent storage driver registers with | |
579 | * us here. If pstore is already mounted, call the platform | |
580 | * read function right away to populate the file system. If not | |
581 | * then the pstore mount code will call us later to fill out | |
582 | * the file system. | |
ca01d6dd TL |
583 | */ |
584 | int pstore_register(struct pstore_info *psi) | |
585 | { | |
0d7cd09a KC |
586 | if (backend && strcmp(backend, psi->name)) { |
587 | pr_warn("ignoring unexpected backend '%s'\n", psi->name); | |
8e48b1a8 | 588 | return -EPERM; |
0d7cd09a | 589 | } |
8e48b1a8 | 590 | |
4c9ec219 KC |
591 | /* Sanity check flags. */ |
592 | if (!psi->flags) { | |
593 | pr_warn("backend '%s' must support at least one frontend\n", | |
594 | psi->name); | |
595 | return -EINVAL; | |
596 | } | |
597 | ||
598 | /* Check for required functions. */ | |
599 | if (!psi->read || !psi->write) { | |
600 | pr_warn("backend '%s' must implement read() and write()\n", | |
601 | psi->name); | |
602 | return -EINVAL; | |
603 | } | |
604 | ||
cab12fd0 | 605 | mutex_lock(&psinfo_lock); |
ca01d6dd | 606 | if (psinfo) { |
0d7cd09a KC |
607 | pr_warn("backend '%s' already loaded: ignoring '%s'\n", |
608 | psinfo->name, psi->name); | |
cab12fd0 | 609 | mutex_unlock(&psinfo_lock); |
ca01d6dd TL |
610 | return -EBUSY; |
611 | } | |
dee28e72 | 612 | |
4c9ec219 KC |
613 | if (!psi->write_user) |
614 | psi->write_user = pstore_write_user_compat; | |
ca01d6dd | 615 | psinfo = psi; |
f6f82851 | 616 | mutex_init(&psinfo->read_mutex); |
8126b1c7 | 617 | spin_lock_init(&psinfo->buf_lock); |
ca01d6dd | 618 | |
8880fa32 KC |
619 | if (psi->flags & PSTORE_FLAGS_DMESG) |
620 | allocate_buf_for_compression(); | |
b0aad7a9 | 621 | |
27e5041a | 622 | pstore_get_records(0); |
ca01d6dd | 623 | |
3524e688 PT |
624 | if (psi->flags & PSTORE_FLAGS_DMESG) { |
625 | pstore_dumper.max_reason = psinfo->max_reason; | |
c950fd6f | 626 | pstore_register_kmsg(); |
3524e688 | 627 | } |
c950fd6f | 628 | if (psi->flags & PSTORE_FLAGS_CONSOLE) |
df36ac1b | 629 | pstore_register_console(); |
c950fd6f | 630 | if (psi->flags & PSTORE_FLAGS_FTRACE) |
df36ac1b | 631 | pstore_register_ftrace(); |
c950fd6f | 632 | if (psi->flags & PSTORE_FLAGS_PMSG) |
9d5438f4 | 633 | pstore_register_pmsg(); |
ca01d6dd | 634 | |
6330d553 | 635 | /* Start watching for new records, if desired. */ |
78c83c82 | 636 | pstore_timer_kick(); |
6dda9266 | 637 | |
42222c2a WL |
638 | /* |
639 | * Update the module parameter backend, so it is visible | |
640 | * through /sys/module/pstore/parameters/backend | |
641 | */ | |
563ca40d | 642 | backend = kstrdup(psi->name, GFP_KERNEL); |
42222c2a | 643 | |
ef748853 | 644 | pr_info("Registered %s as persistent store backend\n", psi->name); |
8e48b1a8 | 645 | |
6248a066 | 646 | mutex_unlock(&psinfo_lock); |
ca01d6dd TL |
647 | return 0; |
648 | } | |
649 | EXPORT_SYMBOL_GPL(pstore_register); | |
650 | ||
ee1d2674 GT |
651 | void pstore_unregister(struct pstore_info *psi) |
652 | { | |
6248a066 KC |
653 | /* It's okay to unregister nothing. */ |
654 | if (!psi) | |
655 | return; | |
656 | ||
657 | mutex_lock(&psinfo_lock); | |
658 | ||
659 | /* Only one backend can be registered at a time. */ | |
660 | if (WARN_ON(psi != psinfo)) { | |
661 | mutex_unlock(&psinfo_lock); | |
662 | return; | |
663 | } | |
664 | ||
78c83c82 | 665 | /* Unregister all callbacks. */ |
c950fd6f | 666 | if (psi->flags & PSTORE_FLAGS_PMSG) |
a1db8060 | 667 | pstore_unregister_pmsg(); |
c950fd6f | 668 | if (psi->flags & PSTORE_FLAGS_FTRACE) |
a1db8060 | 669 | pstore_unregister_ftrace(); |
c950fd6f | 670 | if (psi->flags & PSTORE_FLAGS_CONSOLE) |
a1db8060 | 671 | pstore_unregister_console(); |
c950fd6f NK |
672 | if (psi->flags & PSTORE_FLAGS_DMESG) |
673 | pstore_unregister_kmsg(); | |
ee1d2674 | 674 | |
78c83c82 KC |
675 | /* Stop timer and make sure all work has finished. */ |
676 | del_timer_sync(&pstore_timer); | |
677 | flush_work(&pstore_work); | |
678 | ||
609e28bb KC |
679 | /* Remove all backend records from filesystem tree. */ |
680 | pstore_put_backend_records(psi); | |
681 | ||
ee1d2674 GT |
682 | free_buf_for_compression(); |
683 | ||
684 | psinfo = NULL; | |
563ca40d | 685 | kfree(backend); |
ee1d2674 | 686 | backend = NULL; |
6248a066 | 687 | mutex_unlock(&psinfo_lock); |
ee1d2674 GT |
688 | } |
689 | EXPORT_SYMBOL_GPL(pstore_unregister); | |
690 | ||
634f8f51 KC |
691 | static void decompress_record(struct pstore_record *record) |
692 | { | |
bdabc8e7 | 693 | int ret; |
634f8f51 | 694 | int unzipped_len; |
bdabc8e7 | 695 | char *unzipped, *workspace; |
e4f0a7ec AB |
696 | struct acomp_req *dreq; |
697 | struct scatterlist src, dst; | |
634f8f51 | 698 | |
19d8e914 | 699 | if (!IS_ENABLED(CONFIG_PSTORE_COMPRESS) || !record->compressed) |
4a16d1cb AK |
700 | return; |
701 | ||
634f8f51 | 702 | /* Only PSTORE_TYPE_DMESG support compression. */ |
4a16d1cb | 703 | if (record->type != PSTORE_TYPE_DMESG) { |
634f8f51 KC |
704 | pr_warn("ignored compressed record type %d\n", record->type); |
705 | return; | |
706 | } | |
707 | ||
bdabc8e7 | 708 | /* Missing compression buffer means compression was not initialized. */ |
634f8f51 | 709 | if (!big_oops_buf) { |
bdabc8e7 | 710 | pr_warn("no decompression method initialized!\n"); |
634f8f51 KC |
711 | return; |
712 | } | |
713 | ||
bdabc8e7 KC |
714 | /* Allocate enough space to hold max decompression and ECC. */ |
715 | unzipped_len = big_oops_buf_sz; | |
716 | workspace = kmalloc(unzipped_len + record->ecc_notice_size, | |
717 | GFP_KERNEL); | |
718 | if (!workspace) | |
7e8cc8dc | 719 | return; |
7e8cc8dc | 720 | |
e4f0a7ec AB |
721 | dreq = acomp_request_alloc(tfm); |
722 | if (!dreq) { | |
723 | kfree(workspace); | |
724 | return; | |
725 | } | |
726 | ||
727 | sg_init_table(&src, 1); | |
728 | sg_set_buf(&src, record->buf, record->size); | |
729 | ||
730 | sg_init_table(&dst, 1); | |
731 | sg_set_buf(&dst, workspace, unzipped_len); | |
732 | ||
733 | acomp_request_set_params(dreq, &src, &dst, record->size, unzipped_len); | |
734 | ||
bdabc8e7 | 735 | /* After decompression "unzipped_len" is almost certainly smaller. */ |
e4f0a7ec | 736 | ret = crypto_acomp_decompress(dreq); |
bdabc8e7 | 737 | if (ret) { |
e4f0a7ec | 738 | pr_err("crypto_acomp_decompress failed, ret = %d!\n", ret); |
bdabc8e7 | 739 | kfree(workspace); |
7e8cc8dc KC |
740 | return; |
741 | } | |
7e8cc8dc KC |
742 | |
743 | /* Append ECC notice to decompressed buffer. */ | |
e4f0a7ec | 744 | unzipped_len = dreq->dlen; |
bdabc8e7 | 745 | memcpy(workspace + unzipped_len, record->buf + record->size, |
7e8cc8dc KC |
746 | record->ecc_notice_size); |
747 | ||
bdabc8e7 KC |
748 | /* Copy decompressed contents into an minimum-sized allocation. */ |
749 | unzipped = kmemdup(workspace, unzipped_len + record->ecc_notice_size, | |
750 | GFP_KERNEL); | |
751 | kfree(workspace); | |
e4f0a7ec | 752 | acomp_request_free(dreq); |
bdabc8e7 KC |
753 | if (!unzipped) |
754 | return; | |
755 | ||
756 | /* Swap out compressed contents with decompressed contents. */ | |
7e8cc8dc | 757 | kfree(record->buf); |
bdabc8e7 | 758 | record->buf = unzipped; |
7e8cc8dc KC |
759 | record->size = unzipped_len; |
760 | record->compressed = false; | |
634f8f51 KC |
761 | } |
762 | ||
ca01d6dd | 763 | /* |
3a7d2fd1 | 764 | * Read all the records from one persistent store backend. Create |
6dda9266 TL |
765 | * files in our filesystem. Don't warn about -EEXIST errors |
766 | * when we are re-scanning the backing store looking to add new | |
767 | * error records. | |
ca01d6dd | 768 | */ |
3a7d2fd1 KC |
769 | void pstore_get_backend_records(struct pstore_info *psi, |
770 | struct dentry *root, int quiet) | |
ca01d6dd | 771 | { |
2a2b0acf | 772 | int failed = 0; |
656de42e | 773 | unsigned int stop_loop = 65536; |
ca01d6dd | 774 | |
3a7d2fd1 | 775 | if (!psi || !root) |
ca01d6dd TL |
776 | return; |
777 | ||
f6f82851 | 778 | mutex_lock(&psi->read_mutex); |
2174f6df | 779 | if (psi->open && psi->open(psi)) |
06cf91b4 CG |
780 | goto out; |
781 | ||
1dfff7dd KC |
782 | /* |
783 | * Backend callback read() allocates record.buf. decompress_record() | |
784 | * may reallocate record.buf. On success, pstore_mkfile() will keep | |
785 | * the record.buf, so free it only on failure. | |
786 | */ | |
656de42e | 787 | for (; stop_loop; stop_loop--) { |
2a2b0acf KC |
788 | struct pstore_record *record; |
789 | int rc; | |
790 | ||
791 | record = kzalloc(sizeof(*record), GFP_KERNEL); | |
792 | if (!record) { | |
793 | pr_err("out of memory creating record\n"); | |
794 | break; | |
795 | } | |
e581ca81 | 796 | pstore_record_init(record, psi); |
2a2b0acf KC |
797 | |
798 | record->size = psi->read(record); | |
799 | ||
800 | /* No more records left in backend? */ | |
f6525b96 DA |
801 | if (record->size <= 0) { |
802 | kfree(record); | |
2a2b0acf | 803 | break; |
f6525b96 | 804 | } |
2a2b0acf KC |
805 | |
806 | decompress_record(record); | |
3a7d2fd1 | 807 | rc = pstore_mkfile(root, record); |
1dfff7dd | 808 | if (rc) { |
83f70f07 | 809 | /* pstore_mkfile() did not take record, so free it. */ |
2a2b0acf | 810 | kfree(record->buf); |
8ca869b2 | 811 | kfree(record->priv); |
83f70f07 | 812 | kfree(record); |
1dfff7dd KC |
813 | if (rc != -EEXIST || !quiet) |
814 | failed++; | |
815 | } | |
ca01d6dd | 816 | } |
2174f6df KC |
817 | if (psi->close) |
818 | psi->close(psi); | |
06cf91b4 | 819 | out: |
f6f82851 | 820 | mutex_unlock(&psi->read_mutex); |
ca01d6dd TL |
821 | |
822 | if (failed) | |
656de42e | 823 | pr_warn("failed to create %d record(s) from '%s'\n", |
ef748853 | 824 | failed, psi->name); |
656de42e KC |
825 | if (!stop_loop) |
826 | pr_err("looping? Too many records seen from '%s'\n", | |
827 | psi->name); | |
ca01d6dd TL |
828 | } |
829 | ||
6dda9266 TL |
830 | static void pstore_dowork(struct work_struct *work) |
831 | { | |
832 | pstore_get_records(1); | |
833 | } | |
834 | ||
24ed960a | 835 | static void pstore_timefunc(struct timer_list *unused) |
6dda9266 TL |
836 | { |
837 | if (pstore_new_entry) { | |
838 | pstore_new_entry = 0; | |
839 | schedule_work(&pstore_work); | |
840 | } | |
841 | ||
78c83c82 | 842 | pstore_timer_kick(); |
6dda9266 TL |
843 | } |
844 | ||
8d82cee2 | 845 | static void __init pstore_choose_compression(void) |
fe1d4758 KC |
846 | { |
847 | const struct pstore_zbackend *step; | |
848 | ||
849 | if (!compress) | |
850 | return; | |
851 | ||
852 | for (step = zbackends; step->name; step++) { | |
853 | if (!strcmp(compress, step->name)) { | |
854 | zbackend = step; | |
fe1d4758 KC |
855 | return; |
856 | } | |
857 | } | |
858 | } | |
859 | ||
cb095afd KC |
860 | static int __init pstore_init(void) |
861 | { | |
862 | int ret; | |
863 | ||
864 | pstore_choose_compression(); | |
865 | ||
41603165 JFG |
866 | /* |
867 | * Check if any pstore backends registered earlier but did not | |
868 | * initialize compression because crypto was not ready. If so, | |
869 | * initialize compression now. | |
870 | */ | |
95047b05 | 871 | allocate_buf_for_compression(); |
41603165 | 872 | |
cb095afd KC |
873 | ret = pstore_init_fs(); |
874 | if (ret) | |
8a57d6d4 | 875 | free_buf_for_compression(); |
cb095afd | 876 | |
8a57d6d4 | 877 | return ret; |
cb095afd | 878 | } |
41603165 | 879 | late_initcall(pstore_init); |
cb095afd KC |
880 | |
881 | static void __exit pstore_exit(void) | |
882 | { | |
883 | pstore_exit_fs(); | |
884 | } | |
885 | module_exit(pstore_exit) | |
886 | ||
cb095afd KC |
887 | MODULE_AUTHOR("Tony Luck <tony.luck@intel.com>"); |
888 | MODULE_LICENSE("GPL"); |