blob: 14984d902a99286ad19a27a906fa0ac2a7255613 [file] [log] [blame]
Tony Luckca01d6d2010-12-28 14:25:21 -08001/*
2 * Persistent Storage - platform driver interface parts.
3 *
Anton Vorontsovf29e5952012-05-26 06:20:19 -07004 * Copyright (C) 2007-2008 Google, Inc.
Tony Luckca01d6d2010-12-28 14:25:21 -08005 * Copyright (C) 2010 Intel Corporation <tony.luck@intel.com>
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License version 2 as
9 * published by the Free Software Foundation.
10 *
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
15 *
16 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, write to the Free Software
18 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
19 */
20
Fabian Frederickef748852014-06-06 14:37:31 -070021#define pr_fmt(fmt) "pstore: " fmt
22
Tony Luckca01d6d2010-12-28 14:25:21 -080023#include <linux/atomic.h>
24#include <linux/types.h>
25#include <linux/errno.h>
26#include <linux/init.h>
27#include <linux/kmsg_dump.h>
Anton Vorontsovf29e5952012-05-26 06:20:19 -070028#include <linux/console.h>
Tony Luckca01d6d2010-12-28 14:25:21 -080029#include <linux/module.h>
30#include <linux/pstore.h>
Geliang Tang8cfc8dd2016-02-18 22:04:22 +080031#ifdef CONFIG_PSTORE_ZLIB_COMPRESS
Aruna Balakrishnaiahb0aad7a2013-08-16 13:53:10 -070032#include <linux/zlib.h>
Geliang Tang8cfc8dd2016-02-18 22:04:22 +080033#endif
34#ifdef CONFIG_PSTORE_LZO_COMPRESS
35#include <linux/lzo.h>
36#endif
37#ifdef CONFIG_PSTORE_LZ4_COMPRESS
38#include <linux/lz4.h>
39#endif
Tony Luckca01d6d2010-12-28 14:25:21 -080040#include <linux/string.h>
Luck, Tony6dda9262011-08-11 15:14:39 -070041#include <linux/timer.h>
Tony Luckca01d6d2010-12-28 14:25:21 -080042#include <linux/slab.h>
43#include <linux/uaccess.h>
Don Zickusabd4d552011-08-12 10:54:51 -070044#include <linux/hardirq.h>
Anton Vorontsova3f5f072012-05-26 06:20:28 -070045#include <linux/jiffies.h>
Luck, Tony6dda9262011-08-11 15:14:39 -070046#include <linux/workqueue.h>
Tony Luckca01d6d2010-12-28 14:25:21 -080047
48#include "internal.h"
49
50/*
Luck, Tony6dda9262011-08-11 15:14:39 -070051 * We defer making "oops" entries appear in pstore - see
52 * whether the system is actually still running well enough
53 * to let someone see the entry
54 */
Anton Vorontsov521f72882012-05-26 06:20:29 -070055static int pstore_update_ms = -1;
Anton Vorontsova3f5f072012-05-26 06:20:28 -070056module_param_named(update_ms, pstore_update_ms, int, 0600);
57MODULE_PARM_DESC(update_ms, "milliseconds before pstore updates its content "
Anton Vorontsov521f72882012-05-26 06:20:29 -070058 "(default is -1, which means runtime updates are disabled; "
59 "enabling this option is not safe, it may lead to further "
60 "corruption on Oopses)");
Luck, Tony6dda9262011-08-11 15:14:39 -070061
62static int pstore_new_entry;
63
64static void pstore_timefunc(unsigned long);
65static DEFINE_TIMER(pstore_timer, pstore_timefunc, 0, 0);
66
67static void pstore_dowork(struct work_struct *);
68static DECLARE_WORK(pstore_work, pstore_dowork);
69
70/*
Tony Luckca01d6d2010-12-28 14:25:21 -080071 * pstore_lock just protects "psinfo" during
72 * calls to pstore_register()
73 */
74static DEFINE_SPINLOCK(pstore_lock);
Anton Vorontsov060287b2012-07-09 17:10:41 -070075struct pstore_info *psinfo;
Tony Luckca01d6d2010-12-28 14:25:21 -080076
Matthew Garrettdee28e72011-07-21 16:57:55 -040077static char *backend;
78
Aruna Balakrishnaiahb0aad7a2013-08-16 13:53:10 -070079/* Compression parameters */
Geliang Tang8cfc8dd2016-02-18 22:04:22 +080080#ifdef CONFIG_PSTORE_ZLIB_COMPRESS
Aruna Balakrishnaiahb0aad7a2013-08-16 13:53:10 -070081#define COMPR_LEVEL 6
82#define WINDOW_BITS 12
83#define MEM_LEVEL 4
84static struct z_stream_s stream;
Geliang Tang8cfc8dd2016-02-18 22:04:22 +080085#else
86static unsigned char *workspace;
87#endif
88
89struct pstore_zbackend {
90 int (*compress)(const void *in, void *out, size_t inlen, size_t outlen);
91 int (*decompress)(void *in, void *out, size_t inlen, size_t outlen);
92 void (*allocate)(void);
93 void (*free)(void);
94
95 const char *name;
96};
Aruna Balakrishnaiahb0aad7a2013-08-16 13:53:10 -070097
98static char *big_oops_buf;
99static size_t big_oops_buf_sz;
100
Luck, Tony366f7e72011-03-18 15:33:43 -0700101/* How much of the console log to snapshot */
Tony Luckca01d6d2010-12-28 14:25:21 -0800102static unsigned long kmsg_bytes = 10240;
103
Luck, Tony366f7e72011-03-18 15:33:43 -0700104void pstore_set_kmsg_bytes(int bytes)
Tony Luckca01d6d2010-12-28 14:25:21 -0800105{
Luck, Tony366f7e72011-03-18 15:33:43 -0700106 kmsg_bytes = bytes;
Tony Luckca01d6d2010-12-28 14:25:21 -0800107}
108
Tony Luckca01d6d2010-12-28 14:25:21 -0800109/* Tag each group of saved records with a sequence number */
110static int oopscount;
111
Seiji Aguchi381b8722012-03-16 15:36:59 -0700112static const char *get_reason_str(enum kmsg_dump_reason reason)
113{
114 switch (reason) {
115 case KMSG_DUMP_PANIC:
116 return "Panic";
117 case KMSG_DUMP_OOPS:
118 return "Oops";
119 case KMSG_DUMP_EMERG:
120 return "Emergency";
121 case KMSG_DUMP_RESTART:
122 return "Restart";
123 case KMSG_DUMP_HALT:
124 return "Halt";
125 case KMSG_DUMP_POWEROFF:
126 return "Poweroff";
127 default:
128 return "Unknown";
129 }
130}
Tony Luck9f6af272011-03-22 16:01:49 -0700131
Seiji Aguchi9f244e92013-01-11 18:09:41 +0000132bool pstore_cannot_block_path(enum kmsg_dump_reason reason)
133{
134 /*
135 * In case of NMI path, pstore shouldn't be blocked
136 * regardless of reason.
137 */
138 if (in_nmi())
139 return true;
140
141 switch (reason) {
142 /* In panic case, other cpus are stopped by smp_send_stop(). */
143 case KMSG_DUMP_PANIC:
144 /* Emergency restart shouldn't be blocked by spin lock. */
145 case KMSG_DUMP_EMERG:
146 return true;
147 default:
148 return false;
149 }
150}
151EXPORT_SYMBOL_GPL(pstore_cannot_block_path);
152
Geliang Tang8cfc8dd2016-02-18 22:04:22 +0800153#ifdef CONFIG_PSTORE_ZLIB_COMPRESS
Aruna Balakrishnaiahb0aad7a2013-08-16 13:53:10 -0700154/* Derived from logfs_compress() */
Geliang Tang8cfc8dd2016-02-18 22:04:22 +0800155static int compress_zlib(const void *in, void *out, size_t inlen, size_t outlen)
Aruna Balakrishnaiahb0aad7a2013-08-16 13:53:10 -0700156{
157 int err, ret;
158
159 ret = -EIO;
160 err = zlib_deflateInit2(&stream, COMPR_LEVEL, Z_DEFLATED, WINDOW_BITS,
161 MEM_LEVEL, Z_DEFAULT_STRATEGY);
162 if (err != Z_OK)
163 goto error;
164
165 stream.next_in = in;
166 stream.avail_in = inlen;
167 stream.total_in = 0;
168 stream.next_out = out;
169 stream.avail_out = outlen;
170 stream.total_out = 0;
171
172 err = zlib_deflate(&stream, Z_FINISH);
173 if (err != Z_STREAM_END)
174 goto error;
175
176 err = zlib_deflateEnd(&stream);
177 if (err != Z_OK)
178 goto error;
179
180 if (stream.total_out >= stream.total_in)
181 goto error;
182
183 ret = stream.total_out;
184error:
185 return ret;
186}
187
Aruna Balakrishnaiahadb42f52013-08-16 13:53:28 -0700188/* Derived from logfs_uncompress */
Geliang Tang8cfc8dd2016-02-18 22:04:22 +0800189static int decompress_zlib(void *in, void *out, size_t inlen, size_t outlen)
Aruna Balakrishnaiahadb42f52013-08-16 13:53:28 -0700190{
191 int err, ret;
192
193 ret = -EIO;
Aruna Balakrishnaiahb61edf82013-09-11 10:58:03 -0700194 err = zlib_inflateInit2(&stream, WINDOW_BITS);
Aruna Balakrishnaiahadb42f52013-08-16 13:53:28 -0700195 if (err != Z_OK)
196 goto error;
197
198 stream.next_in = in;
199 stream.avail_in = inlen;
200 stream.total_in = 0;
201 stream.next_out = out;
202 stream.avail_out = outlen;
203 stream.total_out = 0;
204
205 err = zlib_inflate(&stream, Z_FINISH);
206 if (err != Z_STREAM_END)
207 goto error;
208
209 err = zlib_inflateEnd(&stream);
210 if (err != Z_OK)
211 goto error;
212
213 ret = stream.total_out;
214error:
215 return ret;
216}
217
Geliang Tang8cfc8dd2016-02-18 22:04:22 +0800218static void allocate_zlib(void)
Aruna Balakrishnaiahb0aad7a2013-08-16 13:53:10 -0700219{
220 size_t size;
Aruna Balakrishnaiah7de8fe22013-09-11 10:57:41 -0700221 size_t cmpr;
Aruna Balakrishnaiahb0aad7a2013-08-16 13:53:10 -0700222
Aruna Balakrishnaiah7de8fe22013-09-11 10:57:41 -0700223 switch (psinfo->bufsize) {
224 /* buffer range for efivars */
225 case 1000 ... 2000:
226 cmpr = 56;
227 break;
228 case 2001 ... 3000:
229 cmpr = 54;
230 break;
231 case 3001 ... 3999:
232 cmpr = 52;
233 break;
234 /* buffer range for nvram, erst */
235 case 4000 ... 10000:
236 cmpr = 45;
237 break;
238 default:
239 cmpr = 60;
240 break;
241 }
242
243 big_oops_buf_sz = (psinfo->bufsize * 100) / cmpr;
Aruna Balakrishnaiahb0aad7a2013-08-16 13:53:10 -0700244 big_oops_buf = kmalloc(big_oops_buf_sz, GFP_KERNEL);
245 if (big_oops_buf) {
246 size = max(zlib_deflate_workspacesize(WINDOW_BITS, MEM_LEVEL),
247 zlib_inflate_workspacesize());
248 stream.workspace = kmalloc(size, GFP_KERNEL);
249 if (!stream.workspace) {
Fabian Frederickef748852014-06-06 14:37:31 -0700250 pr_err("No memory for compression workspace; skipping compression\n");
Aruna Balakrishnaiahb0aad7a2013-08-16 13:53:10 -0700251 kfree(big_oops_buf);
252 big_oops_buf = NULL;
253 }
254 } else {
Fabian Frederickef748852014-06-06 14:37:31 -0700255 pr_err("No memory for uncompressed data; skipping compression\n");
Aruna Balakrishnaiahb0aad7a2013-08-16 13:53:10 -0700256 stream.workspace = NULL;
257 }
258
259}
260
Geliang Tang8cfc8dd2016-02-18 22:04:22 +0800261static void free_zlib(void)
Geliang Tangee1d2672015-10-20 00:39:03 -0700262{
263 kfree(stream.workspace);
264 stream.workspace = NULL;
265 kfree(big_oops_buf);
266 big_oops_buf = NULL;
Geliang Tang8cfc8dd2016-02-18 22:04:22 +0800267 big_oops_buf_sz = 0;
268}
269
270static struct pstore_zbackend backend_zlib = {
271 .compress = compress_zlib,
272 .decompress = decompress_zlib,
273 .allocate = allocate_zlib,
274 .free = free_zlib,
275 .name = "zlib",
276};
277#endif
278
279#ifdef CONFIG_PSTORE_LZO_COMPRESS
280static int compress_lzo(const void *in, void *out, size_t inlen, size_t outlen)
281{
282 int ret;
283
284 ret = lzo1x_1_compress(in, inlen, out, &outlen, workspace);
285 if (ret != LZO_E_OK) {
286 pr_err("lzo_compress error, ret = %d!\n", ret);
287 return -EIO;
288 }
289
290 return outlen;
291}
292
293static int decompress_lzo(void *in, void *out, size_t inlen, size_t outlen)
294{
295 int ret;
296
297 ret = lzo1x_decompress_safe(in, inlen, out, &outlen);
298 if (ret != LZO_E_OK) {
299 pr_err("lzo_decompress error, ret = %d!\n", ret);
300 return -EIO;
301 }
302
303 return outlen;
304}
305
306static void allocate_lzo(void)
307{
308 big_oops_buf_sz = lzo1x_worst_compress(psinfo->bufsize);
309 big_oops_buf = kmalloc(big_oops_buf_sz, GFP_KERNEL);
310 if (big_oops_buf) {
311 workspace = kmalloc(LZO1X_MEM_COMPRESS, GFP_KERNEL);
312 if (!workspace) {
313 pr_err("No memory for compression workspace; skipping compression\n");
314 kfree(big_oops_buf);
315 big_oops_buf = NULL;
316 }
317 } else {
318 pr_err("No memory for uncompressed data; skipping compression\n");
319 workspace = NULL;
320 }
321}
322
323static void free_lzo(void)
324{
325 kfree(workspace);
326 kfree(big_oops_buf);
327 big_oops_buf = NULL;
328 big_oops_buf_sz = 0;
329}
330
331static struct pstore_zbackend backend_lzo = {
332 .compress = compress_lzo,
333 .decompress = decompress_lzo,
334 .allocate = allocate_lzo,
335 .free = free_lzo,
336 .name = "lzo",
337};
338#endif
339
340#ifdef CONFIG_PSTORE_LZ4_COMPRESS
341static int compress_lz4(const void *in, void *out, size_t inlen, size_t outlen)
342{
343 int ret;
344
345 ret = lz4_compress(in, inlen, out, &outlen, workspace);
346 if (ret) {
347 pr_err("lz4_compress error, ret = %d!\n", ret);
348 return -EIO;
349 }
350
351 return outlen;
352}
353
354static int decompress_lz4(void *in, void *out, size_t inlen, size_t outlen)
355{
356 int ret;
357
358 ret = lz4_decompress_unknownoutputsize(in, inlen, out, &outlen);
359 if (ret) {
360 pr_err("lz4_decompress error, ret = %d!\n", ret);
361 return -EIO;
362 }
363
364 return outlen;
365}
366
367static void allocate_lz4(void)
368{
369 big_oops_buf_sz = lz4_compressbound(psinfo->bufsize);
370 big_oops_buf = kmalloc(big_oops_buf_sz, GFP_KERNEL);
371 if (big_oops_buf) {
372 workspace = kmalloc(LZ4_MEM_COMPRESS, GFP_KERNEL);
373 if (!workspace) {
374 pr_err("No memory for compression workspace; skipping compression\n");
375 kfree(big_oops_buf);
376 big_oops_buf = NULL;
377 }
378 } else {
379 pr_err("No memory for uncompressed data; skipping compression\n");
380 workspace = NULL;
381 }
382}
383
384static void free_lz4(void)
385{
386 kfree(workspace);
387 kfree(big_oops_buf);
388 big_oops_buf = NULL;
389 big_oops_buf_sz = 0;
390}
391
392static struct pstore_zbackend backend_lz4 = {
393 .compress = compress_lz4,
394 .decompress = decompress_lz4,
395 .allocate = allocate_lz4,
396 .free = free_lz4,
397 .name = "lz4",
398};
399#endif
400
401static struct pstore_zbackend *zbackend =
402#if defined(CONFIG_PSTORE_ZLIB_COMPRESS)
403 &backend_zlib;
404#elif defined(CONFIG_PSTORE_LZO_COMPRESS)
405 &backend_lzo;
406#elif defined(CONFIG_PSTORE_LZ4_COMPRESS)
407 &backend_lz4;
408#else
409 NULL;
410#endif
411
412static int pstore_compress(const void *in, void *out,
413 size_t inlen, size_t outlen)
414{
415 if (zbackend)
416 return zbackend->compress(in, out, inlen, outlen);
417 else
418 return -EIO;
419}
420
421static int pstore_decompress(void *in, void *out, size_t inlen, size_t outlen)
422{
423 if (zbackend)
424 return zbackend->decompress(in, out, inlen, outlen);
425 else
426 return -EIO;
427}
428
429static void allocate_buf_for_compression(void)
430{
431 if (zbackend) {
432 pr_info("using %s compression\n", zbackend->name);
433 zbackend->allocate();
434 } else {
435 pr_err("allocate compression buffer error!\n");
436 }
437}
438
439static void free_buf_for_compression(void)
440{
441 if (zbackend)
442 zbackend->free();
443 else
444 pr_err("free compression buffer error!\n");
Geliang Tangee1d2672015-10-20 00:39:03 -0700445}
446
Aruna Balakrishnaiahb0aad7a2013-08-16 13:53:10 -0700447/*
448 * Called when compression fails, since the printk buffer
449 * would be fetched for compression calling it again when
450 * compression fails would have moved the iterator of
451 * printk buffer which results in fetching old contents.
452 * Copy the recent messages from big_oops_buf to psinfo->buf
453 */
454static size_t copy_kmsg_to_buffer(int hsize, size_t len)
455{
456 size_t total_len;
457 size_t diff;
458
459 total_len = hsize + len;
460
461 if (total_len > psinfo->bufsize) {
462 diff = total_len - psinfo->bufsize + hsize;
463 memcpy(psinfo->buf, big_oops_buf, hsize);
464 memcpy(psinfo->buf + hsize, big_oops_buf + diff,
465 psinfo->bufsize - hsize);
466 total_len = psinfo->bufsize;
467 } else
468 memcpy(psinfo->buf, big_oops_buf, total_len);
469
470 return total_len;
471}
472
Tony Luckca01d6d2010-12-28 14:25:21 -0800473/*
474 * callback from kmsg_dump. (s2,l2) has the most recently
475 * written bytes, older bytes are in (s1,l1). Save as much
476 * as we can from the end of the buffer.
477 */
478static void pstore_dump(struct kmsg_dumper *dumper,
Kay Sieverse2ae7152012-06-15 14:07:51 +0200479 enum kmsg_dump_reason reason)
Tony Luckca01d6d2010-12-28 14:25:21 -0800480{
Kay Sieverse2ae7152012-06-15 14:07:51 +0200481 unsigned long total = 0;
Seiji Aguchi381b8722012-03-16 15:36:59 -0700482 const char *why;
Tony Luckca01d6d2010-12-28 14:25:21 -0800483 u64 id;
Matthew Garrettb94fdd02011-07-21 16:57:54 -0400484 unsigned int part = 1;
Don Zickusabd4d552011-08-12 10:54:51 -0700485 unsigned long flags = 0;
Namhyung Kim98e44fd2016-05-18 21:00:05 +0900486 int is_locked;
Kay Sieverse2ae7152012-06-15 14:07:51 +0200487 int ret;
Tony Luckca01d6d2010-12-28 14:25:21 -0800488
Seiji Aguchi381b8722012-03-16 15:36:59 -0700489 why = get_reason_str(reason);
Tony Luck9f6af272011-03-22 16:01:49 -0700490
Seiji Aguchi9f244e92013-01-11 18:09:41 +0000491 if (pstore_cannot_block_path(reason)) {
492 is_locked = spin_trylock_irqsave(&psinfo->buf_lock, flags);
493 if (!is_locked) {
494 pr_err("pstore dump routine blocked in %s path, may corrupt error record\n"
495 , in_nmi() ? "NMI" : why);
496 }
Namhyung Kim98e44fd2016-05-18 21:00:05 +0900497 } else {
Don Zickusabd4d552011-08-12 10:54:51 -0700498 spin_lock_irqsave(&psinfo->buf_lock, flags);
Namhyung Kim98e44fd2016-05-18 21:00:05 +0900499 is_locked = 1;
500 }
Tony Luckca01d6d2010-12-28 14:25:21 -0800501 oopscount++;
502 while (total < kmsg_bytes) {
Kay Sieverse2ae7152012-06-15 14:07:51 +0200503 char *dst;
504 unsigned long size;
505 int hsize;
Aruna Balakrishnaiahb0aad7a2013-08-16 13:53:10 -0700506 int zipped_len = -1;
Kay Sieverse2ae7152012-06-15 14:07:51 +0200507 size_t len;
Namhyung Kim235f6d12016-05-18 21:00:06 +0900508 bool compressed = false;
Aruna Balakrishnaiahb0aad7a2013-08-16 13:53:10 -0700509 size_t total_len;
Kay Sieverse2ae7152012-06-15 14:07:51 +0200510
Konstantin Khlebnikovf0e2efc2015-05-21 09:26:19 -0700511 if (big_oops_buf && is_locked) {
Aruna Balakrishnaiahb0aad7a2013-08-16 13:53:10 -0700512 dst = big_oops_buf;
Namhyung Kim235f6d12016-05-18 21:00:06 +0900513 size = big_oops_buf_sz;
514 } else {
515 dst = psinfo->buf;
516 size = psinfo->bufsize;
517 }
Tony Luckca01d6d2010-12-28 14:25:21 -0800518
Namhyung Kim235f6d12016-05-18 21:00:06 +0900519 hsize = sprintf(dst, "%s#%d Part%u\n", why, oopscount, part);
520 size -= hsize;
Aruna Balakrishnaiahb0aad7a2013-08-16 13:53:10 -0700521
Namhyung Kim235f6d12016-05-18 21:00:06 +0900522 if (!kmsg_dump_get_buffer(dumper, true, dst + hsize,
523 size, &len))
524 break;
525
526 if (big_oops_buf && is_locked) {
Aruna Balakrishnaiahb0aad7a2013-08-16 13:53:10 -0700527 zipped_len = pstore_compress(dst, psinfo->buf,
528 hsize + len, psinfo->bufsize);
529
530 if (zipped_len > 0) {
531 compressed = true;
532 total_len = zipped_len;
533 } else {
Aruna Balakrishnaiahb0aad7a2013-08-16 13:53:10 -0700534 total_len = copy_kmsg_to_buffer(hsize, len);
535 }
536 } else {
Aruna Balakrishnaiahb0aad7a2013-08-16 13:53:10 -0700537 total_len = hsize + len;
538 }
Tony Luckca01d6d2010-12-28 14:25:21 -0800539
Kees Cook3d6d8d22011-11-17 13:13:29 -0800540 ret = psinfo->write(PSTORE_TYPE_DMESG, reason, &id, part,
Aruna Balakrishnaiahb0aad7a2013-08-16 13:53:10 -0700541 oopscount, compressed, total_len, psinfo);
Chen Gongb238b8f2011-10-12 09:17:24 -0700542 if (ret == 0 && reason == KMSG_DUMP_OOPS && pstore_is_mounted())
Luck, Tony6dda9262011-08-11 15:14:39 -0700543 pstore_new_entry = 1;
Kay Sieverse2ae7152012-06-15 14:07:51 +0200544
Aruna Balakrishnaiahb0aad7a2013-08-16 13:53:10 -0700545 total += total_len;
Matthew Garrett56280682011-07-21 16:57:53 -0400546 part++;
Tony Luckca01d6d2010-12-28 14:25:21 -0800547 }
Namhyung Kim98e44fd2016-05-18 21:00:05 +0900548 if (is_locked)
Don Zickusabd4d552011-08-12 10:54:51 -0700549 spin_unlock_irqrestore(&psinfo->buf_lock, flags);
Tony Luckca01d6d2010-12-28 14:25:21 -0800550}
551
552static struct kmsg_dumper pstore_dumper = {
553 .dump = pstore_dump,
554};
555
Geliang Tang306e5c22015-10-31 23:23:15 +0800556/*
557 * Register with kmsg_dump to save last part of console log on panic.
558 */
Geliang Tang18730412015-10-20 00:39:02 -0700559static void pstore_register_kmsg(void)
560{
561 kmsg_dump_register(&pstore_dumper);
562}
563
Geliang Tangee1d2672015-10-20 00:39:03 -0700564static void pstore_unregister_kmsg(void)
565{
566 kmsg_dump_unregister(&pstore_dumper);
567}
568
Anton Vorontsovf29e5952012-05-26 06:20:19 -0700569#ifdef CONFIG_PSTORE_CONSOLE
570static void pstore_console_write(struct console *con, const char *s, unsigned c)
571{
572 const char *e = s + c;
573
574 while (s < e) {
575 unsigned long flags;
Colin Ian King70a6f462012-11-14 11:49:53 +0000576 u64 id;
Anton Vorontsovf29e5952012-05-26 06:20:19 -0700577
578 if (c > psinfo->bufsize)
579 c = psinfo->bufsize;
Chuansheng Liu80c9d032012-09-18 01:43:44 +0800580
581 if (oops_in_progress) {
582 if (!spin_trylock_irqsave(&psinfo->buf_lock, flags))
583 break;
584 } else {
585 spin_lock_irqsave(&psinfo->buf_lock, flags);
586 }
Anton Vorontsovf29e5952012-05-26 06:20:19 -0700587 memcpy(psinfo->buf, s, c);
Aruna Balakrishnaiah6bbbca72013-06-27 14:02:56 +0530588 psinfo->write(PSTORE_TYPE_CONSOLE, 0, &id, 0, 0, 0, c, psinfo);
Anton Vorontsovf29e5952012-05-26 06:20:19 -0700589 spin_unlock_irqrestore(&psinfo->buf_lock, flags);
590 s += c;
591 c = e - s;
592 }
593}
594
595static struct console pstore_console = {
596 .name = "pstore",
597 .write = pstore_console_write,
598 .flags = CON_PRINTBUFFER | CON_ENABLED | CON_ANYTIME,
599 .index = -1,
600};
601
602static void pstore_register_console(void)
603{
604 register_console(&pstore_console);
605}
Geliang Tangee1d2672015-10-20 00:39:03 -0700606
607static void pstore_unregister_console(void)
608{
609 unregister_console(&pstore_console);
610}
Anton Vorontsovf29e5952012-05-26 06:20:19 -0700611#else
612static void pstore_register_console(void) {}
Geliang Tangee1d2672015-10-20 00:39:03 -0700613static void pstore_unregister_console(void) {}
Anton Vorontsovf29e5952012-05-26 06:20:19 -0700614#endif
615
Anton Vorontsov897dba02012-07-09 17:10:40 -0700616static int pstore_write_compat(enum pstore_type_id type,
617 enum kmsg_dump_reason reason,
Seiji Aguchi755d4fe2012-11-26 16:07:44 -0800618 u64 *id, unsigned int part, int count,
Aruna Balakrishnaiahb3b515b2013-08-16 13:52:47 -0700619 bool compressed, size_t size,
Aruna Balakrishnaiah6bbbca72013-06-27 14:02:56 +0530620 struct pstore_info *psi)
Anton Vorontsov897dba02012-07-09 17:10:40 -0700621{
Aruna Balakrishnaiahb3b515b2013-08-16 13:52:47 -0700622 return psi->write_buf(type, reason, id, part, psinfo->buf, compressed,
Aruna Balakrishnaiah6bbbca72013-06-27 14:02:56 +0530623 size, psi);
Anton Vorontsov897dba02012-07-09 17:10:40 -0700624}
625
Mark Salyzyn5bf6d1b2016-09-01 08:13:46 -0700626static int pstore_write_buf_user_compat(enum pstore_type_id type,
627 enum kmsg_dump_reason reason,
628 u64 *id, unsigned int part,
629 const char __user *buf,
630 bool compressed, size_t size,
631 struct pstore_info *psi)
632{
633 unsigned long flags = 0;
634 size_t i, bufsize = size;
635 long ret = 0;
636
637 if (unlikely(!access_ok(VERIFY_READ, buf, size)))
638 return -EFAULT;
639 if (bufsize > psinfo->bufsize)
640 bufsize = psinfo->bufsize;
641 spin_lock_irqsave(&psinfo->buf_lock, flags);
642 for (i = 0; i < size; ) {
643 size_t c = min(size - i, bufsize);
644
645 ret = __copy_from_user(psinfo->buf, buf + i, c);
646 if (unlikely(ret != 0)) {
647 ret = -EFAULT;
648 break;
649 }
650 ret = psi->write_buf(type, reason, id, part, psinfo->buf,
651 compressed, c, psi);
652 if (unlikely(ret < 0))
653 break;
654 i += c;
655 }
656 spin_unlock_irqrestore(&psinfo->buf_lock, flags);
657 return unlikely(ret < 0) ? ret : size;
658}
659
Tony Luckca01d6d2010-12-28 14:25:21 -0800660/*
661 * platform specific persistent storage driver registers with
662 * us here. If pstore is already mounted, call the platform
663 * read function right away to populate the file system. If not
664 * then the pstore mount code will call us later to fill out
665 * the file system.
Tony Luckca01d6d2010-12-28 14:25:21 -0800666 */
667int pstore_register(struct pstore_info *psi)
668{
669 struct module *owner = psi->owner;
670
Lenny Szubowicz8e48b1a2013-06-28 17:11:33 -0400671 if (backend && strcmp(backend, psi->name))
672 return -EPERM;
673
Tony Luckca01d6d2010-12-28 14:25:21 -0800674 spin_lock(&pstore_lock);
675 if (psinfo) {
676 spin_unlock(&pstore_lock);
677 return -EBUSY;
678 }
Matthew Garrettdee28e72011-07-21 16:57:55 -0400679
Anton Vorontsov897dba02012-07-09 17:10:40 -0700680 if (!psi->write)
681 psi->write = pstore_write_compat;
Mark Salyzyn5bf6d1b2016-09-01 08:13:46 -0700682 if (!psi->write_buf_user)
683 psi->write_buf_user = pstore_write_buf_user_compat;
Tony Luckca01d6d2010-12-28 14:25:21 -0800684 psinfo = psi;
Kees Cookf6f82852011-11-17 12:58:07 -0800685 mutex_init(&psinfo->read_mutex);
Tony Luckca01d6d2010-12-28 14:25:21 -0800686 spin_unlock(&pstore_lock);
687
688 if (owner && !try_module_get(owner)) {
689 psinfo = NULL;
690 return -EINVAL;
691 }
692
Aruna Balakrishnaiahb0aad7a2013-08-16 13:53:10 -0700693 allocate_buf_for_compression();
694
Tony Luckca01d6d2010-12-28 14:25:21 -0800695 if (pstore_is_mounted())
Luck, Tony6dda9262011-08-11 15:14:39 -0700696 pstore_get_records(0);
Tony Luckca01d6d2010-12-28 14:25:21 -0800697
Namhyung Kimc950fd62016-07-28 00:08:25 +0900698 if (psi->flags & PSTORE_FLAGS_DMESG)
699 pstore_register_kmsg();
700 if (psi->flags & PSTORE_FLAGS_CONSOLE)
Luck, Tonydf36ac12013-12-18 15:17:10 -0800701 pstore_register_console();
Namhyung Kimc950fd62016-07-28 00:08:25 +0900702 if (psi->flags & PSTORE_FLAGS_FTRACE)
Luck, Tonydf36ac12013-12-18 15:17:10 -0800703 pstore_register_ftrace();
Namhyung Kimc950fd62016-07-28 00:08:25 +0900704 if (psi->flags & PSTORE_FLAGS_PMSG)
Mark Salyzyn9d5438f2015-01-16 16:01:10 -0800705 pstore_register_pmsg();
Tony Luckca01d6d2010-12-28 14:25:21 -0800706
Anton Vorontsova3f5f072012-05-26 06:20:28 -0700707 if (pstore_update_ms >= 0) {
708 pstore_timer.expires = jiffies +
709 msecs_to_jiffies(pstore_update_ms);
710 add_timer(&pstore_timer);
711 }
Luck, Tony6dda9262011-08-11 15:14:39 -0700712
Wang Long42222c22015-05-21 09:34:22 -0700713 /*
714 * Update the module parameter backend, so it is visible
715 * through /sys/module/pstore/parameters/backend
716 */
717 backend = psi->name;
718
Geliang Tangee1d2672015-10-20 00:39:03 -0700719 module_put(owner);
720
Fabian Frederickef748852014-06-06 14:37:31 -0700721 pr_info("Registered %s as persistent store backend\n", psi->name);
Lenny Szubowicz8e48b1a2013-06-28 17:11:33 -0400722
Tony Luckca01d6d2010-12-28 14:25:21 -0800723 return 0;
724}
725EXPORT_SYMBOL_GPL(pstore_register);
726
Geliang Tangee1d2672015-10-20 00:39:03 -0700727void pstore_unregister(struct pstore_info *psi)
728{
Namhyung Kimc950fd62016-07-28 00:08:25 +0900729 if (psi->flags & PSTORE_FLAGS_PMSG)
Kees Cooka1db8062016-05-19 10:59:03 -0400730 pstore_unregister_pmsg();
Namhyung Kimc950fd62016-07-28 00:08:25 +0900731 if (psi->flags & PSTORE_FLAGS_FTRACE)
Kees Cooka1db8062016-05-19 10:59:03 -0400732 pstore_unregister_ftrace();
Namhyung Kimc950fd62016-07-28 00:08:25 +0900733 if (psi->flags & PSTORE_FLAGS_CONSOLE)
Kees Cooka1db8062016-05-19 10:59:03 -0400734 pstore_unregister_console();
Namhyung Kimc950fd62016-07-28 00:08:25 +0900735 if (psi->flags & PSTORE_FLAGS_DMESG)
736 pstore_unregister_kmsg();
Geliang Tangee1d2672015-10-20 00:39:03 -0700737
738 free_buf_for_compression();
739
740 psinfo = NULL;
741 backend = NULL;
742}
743EXPORT_SYMBOL_GPL(pstore_unregister);
744
Tony Luckca01d6d2010-12-28 14:25:21 -0800745/*
Luck, Tony6dda9262011-08-11 15:14:39 -0700746 * Read all the records from the persistent store. Create
747 * files in our filesystem. Don't warn about -EEXIST errors
748 * when we are re-scanning the backing store looking to add new
749 * error records.
Tony Luckca01d6d2010-12-28 14:25:21 -0800750 */
Luck, Tony6dda9262011-08-11 15:14:39 -0700751void pstore_get_records(int quiet)
Tony Luckca01d6d2010-12-28 14:25:21 -0800752{
753 struct pstore_info *psi = psinfo;
Kees Cookf6f82852011-11-17 12:58:07 -0800754 char *buf = NULL;
Chen Gong8d38d742011-05-16 10:58:57 -0700755 ssize_t size;
Tony Luckca01d6d2010-12-28 14:25:21 -0800756 u64 id;
Seiji Aguchi755d4fe2012-11-26 16:07:44 -0800757 int count;
Tony Luckca01d6d2010-12-28 14:25:21 -0800758 enum pstore_type_id type;
759 struct timespec time;
Chen Gong06cf91b2011-05-16 11:00:27 -0700760 int failed = 0, rc;
Aruna Balakrishnaiah9a4e1392013-08-16 13:53:19 -0700761 bool compressed;
Aruna Balakrishnaiahadb42f52013-08-16 13:53:28 -0700762 int unzipped_len = -1;
Geliang Tang8cfc8dd2016-02-18 22:04:22 +0800763 ssize_t ecc_notice_size = 0;
Tony Luckca01d6d2010-12-28 14:25:21 -0800764
765 if (!psi)
766 return;
767
Kees Cookf6f82852011-11-17 12:58:07 -0800768 mutex_lock(&psi->read_mutex);
Kees Cook2174f6d2011-11-18 13:49:00 -0800769 if (psi->open && psi->open(psi))
Chen Gong06cf91b2011-05-16 11:00:27 -0700770 goto out;
771
Aruna Balakrishnaiah9a4e1392013-08-16 13:53:19 -0700772 while ((size = psi->read(&id, &type, &count, &time, &buf, &compressed,
Geliang Tang8cfc8dd2016-02-18 22:04:22 +0800773 &ecc_notice_size, psi)) > 0) {
Aruna Balakrishnaiahadb42f52013-08-16 13:53:28 -0700774 if (compressed && (type == PSTORE_TYPE_DMESG)) {
775 if (big_oops_buf)
776 unzipped_len = pstore_decompress(buf,
777 big_oops_buf, size,
778 big_oops_buf_sz);
779
780 if (unzipped_len > 0) {
Geliang Tang8cfc8dd2016-02-18 22:04:22 +0800781 if (ecc_notice_size)
782 memcpy(big_oops_buf + unzipped_len,
783 buf + size, ecc_notice_size);
Liu ShuoXe32634f2014-03-12 21:34:06 +0800784 kfree(buf);
Aruna Balakrishnaiahadb42f52013-08-16 13:53:28 -0700785 buf = big_oops_buf;
786 size = unzipped_len;
Aruna Balakrishnaiah9ad2cbe2013-08-16 13:53:39 -0700787 compressed = false;
Aruna Balakrishnaiahadb42f52013-08-16 13:53:28 -0700788 } else {
Fabian Frederickef748852014-06-06 14:37:31 -0700789 pr_err("decompression failed;returned %d\n",
790 unzipped_len);
Aruna Balakrishnaiah9ad2cbe2013-08-16 13:53:39 -0700791 compressed = true;
Aruna Balakrishnaiahadb42f52013-08-16 13:53:28 -0700792 }
793 }
Seiji Aguchi755d4fe2012-11-26 16:07:44 -0800794 rc = pstore_mkfile(type, psi->name, id, count, buf,
Geliang Tang8cfc8dd2016-02-18 22:04:22 +0800795 compressed, size + ecc_notice_size,
796 time, psi);
Aruna Balakrishnaiahadb42f52013-08-16 13:53:28 -0700797 if (unzipped_len < 0) {
798 /* Free buffer other than big oops */
799 kfree(buf);
800 buf = NULL;
801 } else
802 unzipped_len = -1;
Luck, Tony6dda9262011-08-11 15:14:39 -0700803 if (rc && (rc != -EEXIST || !quiet))
Tony Luckca01d6d2010-12-28 14:25:21 -0800804 failed++;
805 }
Kees Cook2174f6d2011-11-18 13:49:00 -0800806 if (psi->close)
807 psi->close(psi);
Chen Gong06cf91b2011-05-16 11:00:27 -0700808out:
Kees Cookf6f82852011-11-17 12:58:07 -0800809 mutex_unlock(&psi->read_mutex);
Tony Luckca01d6d2010-12-28 14:25:21 -0800810
811 if (failed)
Fabian Frederickef748852014-06-06 14:37:31 -0700812 pr_warn("failed to load %d record(s) from '%s'\n",
813 failed, psi->name);
Tony Luckca01d6d2010-12-28 14:25:21 -0800814}
815
Luck, Tony6dda9262011-08-11 15:14:39 -0700816static void pstore_dowork(struct work_struct *work)
817{
818 pstore_get_records(1);
819}
820
821static void pstore_timefunc(unsigned long dummy)
822{
823 if (pstore_new_entry) {
824 pstore_new_entry = 0;
825 schedule_work(&pstore_work);
826 }
827
Anton Vorontsova3f5f072012-05-26 06:20:28 -0700828 mod_timer(&pstore_timer, jiffies + msecs_to_jiffies(pstore_update_ms));
Luck, Tony6dda9262011-08-11 15:14:39 -0700829}
830
Matthew Garrettdee28e72011-07-21 16:57:55 -0400831module_param(backend, charp, 0444);
832MODULE_PARM_DESC(backend, "Pstore backend to use");