blob: 691032107f8c78776668a93ca4c546dc2a46282a [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
Kees Cook24ed9602017-08-28 11:28:21 -070064static void pstore_timefunc(struct timer_list *);
Kees Cook1d27e3e2017-10-04 16:27:04 -070065static DEFINE_TIMER(pstore_timer, pstore_timefunc);
Luck, Tony6dda9262011-08-11 15:14:39 -070066
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 */
David Howells349d7432017-07-05 16:24:34 +0100102unsigned long kmsg_bytes = PSTORE_DEFAULT_KMSG_BYTES;
Tony Luckca01d6d2010-12-28 14:25:21 -0800103
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
Bhumika Goyal3faf9352017-02-19 15:07:53 +0530270static const struct pstore_zbackend backend_zlib = {
Geliang Tang8cfc8dd2016-02-18 22:04:22 +0800271 .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
Bhumika Goyal3faf9352017-02-19 15:07:53 +0530331static const struct pstore_zbackend backend_lzo = {
Geliang Tang8cfc8dd2016-02-18 22:04:22 +0800332 .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
Sven Schmidtd21b5ff122017-02-24 15:01:22 -0800345 ret = LZ4_compress_default(in, out, inlen, outlen, workspace);
346 if (!ret) {
347 pr_err("LZ4_compress_default error; compression failed!\n");
Geliang Tang8cfc8dd2016-02-18 22:04:22 +0800348 return -EIO;
349 }
350
Sven Schmidtd21b5ff122017-02-24 15:01:22 -0800351 return ret;
Geliang Tang8cfc8dd2016-02-18 22:04:22 +0800352}
353
354static int decompress_lz4(void *in, void *out, size_t inlen, size_t outlen)
355{
356 int ret;
357
Sven Schmidtd21b5ff122017-02-24 15:01:22 -0800358 ret = LZ4_decompress_safe(in, out, inlen, outlen);
359 if (ret < 0) {
360 /*
361 * LZ4_decompress_safe will return an error code
362 * (< 0) if decompression failed
363 */
364 pr_err("LZ4_decompress_safe error, ret = %d!\n", ret);
Geliang Tang8cfc8dd2016-02-18 22:04:22 +0800365 return -EIO;
366 }
367
Sven Schmidtd21b5ff122017-02-24 15:01:22 -0800368 return ret;
Geliang Tang8cfc8dd2016-02-18 22:04:22 +0800369}
370
371static void allocate_lz4(void)
372{
Sven Schmidtd21b5ff122017-02-24 15:01:22 -0800373 big_oops_buf_sz = LZ4_compressBound(psinfo->bufsize);
Geliang Tang8cfc8dd2016-02-18 22:04:22 +0800374 big_oops_buf = kmalloc(big_oops_buf_sz, GFP_KERNEL);
375 if (big_oops_buf) {
376 workspace = kmalloc(LZ4_MEM_COMPRESS, GFP_KERNEL);
377 if (!workspace) {
378 pr_err("No memory for compression workspace; skipping compression\n");
379 kfree(big_oops_buf);
380 big_oops_buf = NULL;
381 }
382 } else {
383 pr_err("No memory for uncompressed data; skipping compression\n");
384 workspace = NULL;
385 }
386}
387
388static void free_lz4(void)
389{
390 kfree(workspace);
391 kfree(big_oops_buf);
392 big_oops_buf = NULL;
393 big_oops_buf_sz = 0;
394}
395
Bhumika Goyal3faf9352017-02-19 15:07:53 +0530396static const struct pstore_zbackend backend_lz4 = {
Geliang Tang8cfc8dd2016-02-18 22:04:22 +0800397 .compress = compress_lz4,
398 .decompress = decompress_lz4,
399 .allocate = allocate_lz4,
400 .free = free_lz4,
401 .name = "lz4",
402};
403#endif
404
Bhumika Goyal3faf9352017-02-19 15:07:53 +0530405static const struct pstore_zbackend *zbackend =
Geliang Tang8cfc8dd2016-02-18 22:04:22 +0800406#if defined(CONFIG_PSTORE_ZLIB_COMPRESS)
407 &backend_zlib;
408#elif defined(CONFIG_PSTORE_LZO_COMPRESS)
409 &backend_lzo;
410#elif defined(CONFIG_PSTORE_LZ4_COMPRESS)
411 &backend_lz4;
412#else
413 NULL;
414#endif
415
416static int pstore_compress(const void *in, void *out,
417 size_t inlen, size_t outlen)
418{
419 if (zbackend)
420 return zbackend->compress(in, out, inlen, outlen);
421 else
422 return -EIO;
423}
424
425static int pstore_decompress(void *in, void *out, size_t inlen, size_t outlen)
426{
427 if (zbackend)
428 return zbackend->decompress(in, out, inlen, outlen);
429 else
430 return -EIO;
431}
432
433static void allocate_buf_for_compression(void)
434{
435 if (zbackend) {
436 pr_info("using %s compression\n", zbackend->name);
437 zbackend->allocate();
438 } else {
439 pr_err("allocate compression buffer error!\n");
440 }
441}
442
443static void free_buf_for_compression(void)
444{
445 if (zbackend)
446 zbackend->free();
447 else
448 pr_err("free compression buffer error!\n");
Geliang Tangee1d2672015-10-20 00:39:03 -0700449}
450
Aruna Balakrishnaiahb0aad7a2013-08-16 13:53:10 -0700451/*
452 * Called when compression fails, since the printk buffer
453 * would be fetched for compression calling it again when
454 * compression fails would have moved the iterator of
455 * printk buffer which results in fetching old contents.
456 * Copy the recent messages from big_oops_buf to psinfo->buf
457 */
458static size_t copy_kmsg_to_buffer(int hsize, size_t len)
459{
460 size_t total_len;
461 size_t diff;
462
463 total_len = hsize + len;
464
465 if (total_len > psinfo->bufsize) {
466 diff = total_len - psinfo->bufsize + hsize;
467 memcpy(psinfo->buf, big_oops_buf, hsize);
468 memcpy(psinfo->buf + hsize, big_oops_buf + diff,
469 psinfo->bufsize - hsize);
470 total_len = psinfo->bufsize;
471 } else
472 memcpy(psinfo->buf, big_oops_buf, total_len);
473
474 return total_len;
475}
476
Kees Cooke581ca82017-05-19 15:10:31 -0700477void pstore_record_init(struct pstore_record *record,
478 struct pstore_info *psinfo)
479{
480 memset(record, 0, sizeof(*record));
481
482 record->psi = psinfo;
Kees Cookc7f3c5952017-05-19 15:29:10 -0700483
484 /* Report zeroed timestamp if called before timekeeping has resumed. */
Arnd Bergmanndf270672017-11-10 16:25:04 +0100485 record->time = ns_to_timespec(ktime_get_real_fast_ns());
Kees Cooke581ca82017-05-19 15:10:31 -0700486}
487
Tony Luckca01d6d2010-12-28 14:25:21 -0800488/*
489 * callback from kmsg_dump. (s2,l2) has the most recently
490 * written bytes, older bytes are in (s1,l1). Save as much
491 * as we can from the end of the buffer.
492 */
493static void pstore_dump(struct kmsg_dumper *dumper,
Kay Sieverse2ae7152012-06-15 14:07:51 +0200494 enum kmsg_dump_reason reason)
Tony Luckca01d6d2010-12-28 14:25:21 -0800495{
Kay Sieverse2ae7152012-06-15 14:07:51 +0200496 unsigned long total = 0;
Seiji Aguchi381b8722012-03-16 15:36:59 -0700497 const char *why;
Matthew Garrettb94fdd02011-07-21 16:57:54 -0400498 unsigned int part = 1;
Don Zickusabd4d552011-08-12 10:54:51 -0700499 unsigned long flags = 0;
Namhyung Kim98e44fda2016-05-18 21:00:05 +0900500 int is_locked;
Kay Sieverse2ae7152012-06-15 14:07:51 +0200501 int ret;
Tony Luckca01d6d2010-12-28 14:25:21 -0800502
Seiji Aguchi381b8722012-03-16 15:36:59 -0700503 why = get_reason_str(reason);
Tony Luck9f6af272011-03-22 16:01:49 -0700504
Seiji Aguchi9f244e92013-01-11 18:09:41 +0000505 if (pstore_cannot_block_path(reason)) {
506 is_locked = spin_trylock_irqsave(&psinfo->buf_lock, flags);
507 if (!is_locked) {
508 pr_err("pstore dump routine blocked in %s path, may corrupt error record\n"
509 , in_nmi() ? "NMI" : why);
Li Pengcheng959217c82016-11-05 10:15:59 +0800510 return;
Seiji Aguchi9f244e92013-01-11 18:09:41 +0000511 }
Namhyung Kim98e44fda2016-05-18 21:00:05 +0900512 } else {
Don Zickusabd4d552011-08-12 10:54:51 -0700513 spin_lock_irqsave(&psinfo->buf_lock, flags);
Namhyung Kim98e44fda2016-05-18 21:00:05 +0900514 is_locked = 1;
515 }
Tony Luckca01d6d2010-12-28 14:25:21 -0800516 oopscount++;
517 while (total < kmsg_bytes) {
Kay Sieverse2ae7152012-06-15 14:07:51 +0200518 char *dst;
Kees Cook76cc9582017-03-03 23:28:53 -0800519 size_t dst_size;
520 int header_size;
Aruna Balakrishnaiahb0aad7a2013-08-16 13:53:10 -0700521 int zipped_len = -1;
Kees Cook76cc9582017-03-03 23:28:53 -0800522 size_t dump_size;
Kees Cooke581ca82017-05-19 15:10:31 -0700523 struct pstore_record record;
524
525 pstore_record_init(&record, psinfo);
526 record.type = PSTORE_TYPE_DMESG;
527 record.count = oopscount;
528 record.reason = reason;
529 record.part = part;
530 record.buf = psinfo->buf;
Kay Sieverse2ae7152012-06-15 14:07:51 +0200531
Konstantin Khlebnikovf0e2efc2015-05-21 09:26:19 -0700532 if (big_oops_buf && is_locked) {
Aruna Balakrishnaiahb0aad7a2013-08-16 13:53:10 -0700533 dst = big_oops_buf;
Kees Cook76cc9582017-03-03 23:28:53 -0800534 dst_size = big_oops_buf_sz;
Namhyung Kim235f6d12016-05-18 21:00:06 +0900535 } else {
536 dst = psinfo->buf;
Kees Cook76cc9582017-03-03 23:28:53 -0800537 dst_size = psinfo->bufsize;
Namhyung Kim235f6d12016-05-18 21:00:06 +0900538 }
Tony Luckca01d6d2010-12-28 14:25:21 -0800539
Kees Cook76cc9582017-03-03 23:28:53 -0800540 /* Write dump header. */
541 header_size = snprintf(dst, dst_size, "%s#%d Part%u\n", why,
542 oopscount, part);
543 dst_size -= header_size;
Aruna Balakrishnaiahb0aad7a2013-08-16 13:53:10 -0700544
Kees Cook76cc9582017-03-03 23:28:53 -0800545 /* Write dump contents. */
546 if (!kmsg_dump_get_buffer(dumper, true, dst + header_size,
547 dst_size, &dump_size))
Namhyung Kim235f6d12016-05-18 21:00:06 +0900548 break;
549
550 if (big_oops_buf && is_locked) {
Aruna Balakrishnaiahb0aad7a2013-08-16 13:53:10 -0700551 zipped_len = pstore_compress(dst, psinfo->buf,
Kees Cook76cc9582017-03-03 23:28:53 -0800552 header_size + dump_size,
553 psinfo->bufsize);
Aruna Balakrishnaiahb0aad7a2013-08-16 13:53:10 -0700554
555 if (zipped_len > 0) {
Kees Cook76cc9582017-03-03 23:28:53 -0800556 record.compressed = true;
557 record.size = zipped_len;
Aruna Balakrishnaiahb0aad7a2013-08-16 13:53:10 -0700558 } else {
Kees Cook76cc9582017-03-03 23:28:53 -0800559 record.size = copy_kmsg_to_buffer(header_size,
560 dump_size);
Aruna Balakrishnaiahb0aad7a2013-08-16 13:53:10 -0700561 }
562 } else {
Kees Cook76cc9582017-03-03 23:28:53 -0800563 record.size = header_size + dump_size;
Aruna Balakrishnaiahb0aad7a2013-08-16 13:53:10 -0700564 }
Tony Luckca01d6d2010-12-28 14:25:21 -0800565
Kees Cook76cc9582017-03-03 23:28:53 -0800566 ret = psinfo->write(&record);
Chen Gongb238b8f2011-10-12 09:17:24 -0700567 if (ret == 0 && reason == KMSG_DUMP_OOPS && pstore_is_mounted())
Luck, Tony6dda9262011-08-11 15:14:39 -0700568 pstore_new_entry = 1;
Kay Sieverse2ae7152012-06-15 14:07:51 +0200569
Kees Cook76cc9582017-03-03 23:28:53 -0800570 total += record.size;
Matthew Garrett56280682011-07-21 16:57:53 -0400571 part++;
Tony Luckca01d6d2010-12-28 14:25:21 -0800572 }
Namhyung Kim98e44fda2016-05-18 21:00:05 +0900573 if (is_locked)
Don Zickusabd4d552011-08-12 10:54:51 -0700574 spin_unlock_irqrestore(&psinfo->buf_lock, flags);
Tony Luckca01d6d2010-12-28 14:25:21 -0800575}
576
577static struct kmsg_dumper pstore_dumper = {
578 .dump = pstore_dump,
579};
580
Geliang Tang306e5c22015-10-31 23:23:15 +0800581/*
582 * Register with kmsg_dump to save last part of console log on panic.
583 */
Geliang Tang18730412015-10-20 00:39:02 -0700584static void pstore_register_kmsg(void)
585{
586 kmsg_dump_register(&pstore_dumper);
587}
588
Geliang Tangee1d2672015-10-20 00:39:03 -0700589static void pstore_unregister_kmsg(void)
590{
591 kmsg_dump_unregister(&pstore_dumper);
592}
593
Anton Vorontsovf29e5952012-05-26 06:20:19 -0700594#ifdef CONFIG_PSTORE_CONSOLE
595static void pstore_console_write(struct console *con, const char *s, unsigned c)
596{
597 const char *e = s + c;
598
599 while (s < e) {
Kees Cooke581ca82017-05-19 15:10:31 -0700600 struct pstore_record record;
Anton Vorontsovf29e5952012-05-26 06:20:19 -0700601 unsigned long flags;
602
Kees Cooke581ca82017-05-19 15:10:31 -0700603 pstore_record_init(&record, psinfo);
604 record.type = PSTORE_TYPE_CONSOLE;
605
Anton Vorontsovf29e5952012-05-26 06:20:19 -0700606 if (c > psinfo->bufsize)
607 c = psinfo->bufsize;
Chuansheng Liu80c9d032012-09-18 01:43:44 +0800608
609 if (oops_in_progress) {
610 if (!spin_trylock_irqsave(&psinfo->buf_lock, flags))
611 break;
612 } else {
613 spin_lock_irqsave(&psinfo->buf_lock, flags);
614 }
Kees Cookb10b4712017-03-05 00:27:54 -0800615 record.buf = (char *)s;
616 record.size = c;
Kees Cook4c9ec212017-03-05 22:41:10 -0800617 psinfo->write(&record);
Anton Vorontsovf29e5952012-05-26 06:20:19 -0700618 spin_unlock_irqrestore(&psinfo->buf_lock, flags);
619 s += c;
620 c = e - s;
621 }
622}
623
624static struct console pstore_console = {
625 .name = "pstore",
626 .write = pstore_console_write,
627 .flags = CON_PRINTBUFFER | CON_ENABLED | CON_ANYTIME,
628 .index = -1,
629};
630
631static void pstore_register_console(void)
632{
633 register_console(&pstore_console);
634}
Geliang Tangee1d2672015-10-20 00:39:03 -0700635
636static void pstore_unregister_console(void)
637{
638 unregister_console(&pstore_console);
639}
Anton Vorontsovf29e5952012-05-26 06:20:19 -0700640#else
641static void pstore_register_console(void) {}
Geliang Tangee1d2672015-10-20 00:39:03 -0700642static void pstore_unregister_console(void) {}
Anton Vorontsovf29e5952012-05-26 06:20:19 -0700643#endif
644
Kees Cook4c9ec212017-03-05 22:41:10 -0800645static int pstore_write_user_compat(struct pstore_record *record,
646 const char __user *buf)
Mark Salyzyn5bf6d1b2016-09-01 08:13:46 -0700647{
Kees Cook30800d92017-03-07 13:57:11 -0800648 int ret = 0;
Mark Salyzyn5bf6d1b2016-09-01 08:13:46 -0700649
Kees Cook30800d92017-03-07 13:57:11 -0800650 if (record->buf)
651 return -EINVAL;
Mark Salyzyn5bf6d1b2016-09-01 08:13:46 -0700652
Geliang Tang077090a2017-04-29 09:45:16 +0800653 record->buf = memdup_user(buf, record->size);
Hirofumi Nakagawadfd6fa32017-09-26 03:21:27 +0900654 if (IS_ERR(record->buf)) {
Geliang Tang077090a2017-04-29 09:45:16 +0800655 ret = PTR_ERR(record->buf);
Kees Cook30800d92017-03-07 13:57:11 -0800656 goto out;
Mark Salyzyn5bf6d1b2016-09-01 08:13:46 -0700657 }
Kees Cook30800d92017-03-07 13:57:11 -0800658
659 ret = record->psi->write(record);
660
Kees Cook30800d92017-03-07 13:57:11 -0800661 kfree(record->buf);
Geliang Tang077090a2017-04-29 09:45:16 +0800662out:
Kees Cook30800d92017-03-07 13:57:11 -0800663 record->buf = NULL;
664
665 return unlikely(ret < 0) ? ret : record->size;
Mark Salyzyn5bf6d1b2016-09-01 08:13:46 -0700666}
667
Tony Luckca01d6d2010-12-28 14:25:21 -0800668/*
669 * platform specific persistent storage driver registers with
670 * us here. If pstore is already mounted, call the platform
671 * read function right away to populate the file system. If not
672 * then the pstore mount code will call us later to fill out
673 * the file system.
Tony Luckca01d6d2010-12-28 14:25:21 -0800674 */
675int pstore_register(struct pstore_info *psi)
676{
677 struct module *owner = psi->owner;
678
Kees Cook0d7cd092017-03-03 12:11:40 -0800679 if (backend && strcmp(backend, psi->name)) {
680 pr_warn("ignoring unexpected backend '%s'\n", psi->name);
Lenny Szubowicz8e48b1a2013-06-28 17:11:33 -0400681 return -EPERM;
Kees Cook0d7cd092017-03-03 12:11:40 -0800682 }
Lenny Szubowicz8e48b1a2013-06-28 17:11:33 -0400683
Kees Cook4c9ec212017-03-05 22:41:10 -0800684 /* Sanity check flags. */
685 if (!psi->flags) {
686 pr_warn("backend '%s' must support at least one frontend\n",
687 psi->name);
688 return -EINVAL;
689 }
690
691 /* Check for required functions. */
692 if (!psi->read || !psi->write) {
693 pr_warn("backend '%s' must implement read() and write()\n",
694 psi->name);
695 return -EINVAL;
696 }
697
Tony Luckca01d6d2010-12-28 14:25:21 -0800698 spin_lock(&pstore_lock);
699 if (psinfo) {
Kees Cook0d7cd092017-03-03 12:11:40 -0800700 pr_warn("backend '%s' already loaded: ignoring '%s'\n",
701 psinfo->name, psi->name);
Tony Luckca01d6d2010-12-28 14:25:21 -0800702 spin_unlock(&pstore_lock);
703 return -EBUSY;
704 }
Matthew Garrettdee28e72011-07-21 16:57:55 -0400705
Kees Cook4c9ec212017-03-05 22:41:10 -0800706 if (!psi->write_user)
707 psi->write_user = pstore_write_user_compat;
Tony Luckca01d6d2010-12-28 14:25:21 -0800708 psinfo = psi;
Kees Cookf6f82852011-11-17 12:58:07 -0800709 mutex_init(&psinfo->read_mutex);
Tony Luckca01d6d2010-12-28 14:25:21 -0800710 spin_unlock(&pstore_lock);
711
712 if (owner && !try_module_get(owner)) {
713 psinfo = NULL;
714 return -EINVAL;
715 }
716
Aruna Balakrishnaiahb0aad7a2013-08-16 13:53:10 -0700717 allocate_buf_for_compression();
718
Tony Luckca01d6d2010-12-28 14:25:21 -0800719 if (pstore_is_mounted())
Luck, Tony6dda9262011-08-11 15:14:39 -0700720 pstore_get_records(0);
Tony Luckca01d6d2010-12-28 14:25:21 -0800721
Namhyung Kimc950fd62016-07-28 00:08:25 +0900722 if (psi->flags & PSTORE_FLAGS_DMESG)
723 pstore_register_kmsg();
724 if (psi->flags & PSTORE_FLAGS_CONSOLE)
Luck, Tonydf36ac12013-12-18 15:17:10 -0800725 pstore_register_console();
Namhyung Kimc950fd62016-07-28 00:08:25 +0900726 if (psi->flags & PSTORE_FLAGS_FTRACE)
Luck, Tonydf36ac12013-12-18 15:17:10 -0800727 pstore_register_ftrace();
Namhyung Kimc950fd62016-07-28 00:08:25 +0900728 if (psi->flags & PSTORE_FLAGS_PMSG)
Mark Salyzyn9d5438f2015-01-16 16:01:10 -0800729 pstore_register_pmsg();
Tony Luckca01d6d2010-12-28 14:25:21 -0800730
Kees Cook6330d552017-03-06 12:42:12 -0800731 /* Start watching for new records, if desired. */
Anton Vorontsova3f5f072012-05-26 06:20:28 -0700732 if (pstore_update_ms >= 0) {
733 pstore_timer.expires = jiffies +
734 msecs_to_jiffies(pstore_update_ms);
735 add_timer(&pstore_timer);
736 }
Luck, Tony6dda9262011-08-11 15:14:39 -0700737
Wang Long42222c22015-05-21 09:34:22 -0700738 /*
739 * Update the module parameter backend, so it is visible
740 * through /sys/module/pstore/parameters/backend
741 */
742 backend = psi->name;
743
Fabian Frederickef748852014-06-06 14:37:31 -0700744 pr_info("Registered %s as persistent store backend\n", psi->name);
Lenny Szubowicz8e48b1a2013-06-28 17:11:33 -0400745
Kees Cook1344dd82017-03-03 17:45:38 -0800746 module_put(owner);
747
Tony Luckca01d6d2010-12-28 14:25:21 -0800748 return 0;
749}
750EXPORT_SYMBOL_GPL(pstore_register);
751
Geliang Tangee1d2672015-10-20 00:39:03 -0700752void pstore_unregister(struct pstore_info *psi)
753{
Kees Cook6330d552017-03-06 12:42:12 -0800754 /* Stop timer and make sure all work has finished. */
755 pstore_update_ms = -1;
756 del_timer_sync(&pstore_timer);
757 flush_work(&pstore_work);
758
Namhyung Kimc950fd62016-07-28 00:08:25 +0900759 if (psi->flags & PSTORE_FLAGS_PMSG)
Kees Cooka1db8062016-05-19 10:59:03 -0400760 pstore_unregister_pmsg();
Namhyung Kimc950fd62016-07-28 00:08:25 +0900761 if (psi->flags & PSTORE_FLAGS_FTRACE)
Kees Cooka1db8062016-05-19 10:59:03 -0400762 pstore_unregister_ftrace();
Namhyung Kimc950fd62016-07-28 00:08:25 +0900763 if (psi->flags & PSTORE_FLAGS_CONSOLE)
Kees Cooka1db8062016-05-19 10:59:03 -0400764 pstore_unregister_console();
Namhyung Kimc950fd62016-07-28 00:08:25 +0900765 if (psi->flags & PSTORE_FLAGS_DMESG)
766 pstore_unregister_kmsg();
Geliang Tangee1d2672015-10-20 00:39:03 -0700767
768 free_buf_for_compression();
769
770 psinfo = NULL;
771 backend = NULL;
772}
773EXPORT_SYMBOL_GPL(pstore_unregister);
774
Kees Cook634f8f52017-03-03 17:35:25 -0800775static void decompress_record(struct pstore_record *record)
776{
777 int unzipped_len;
Kees Cook7e8cc8d2017-03-04 22:28:46 -0800778 char *decompressed;
Kees Cook634f8f52017-03-03 17:35:25 -0800779
Ankit Kumar4a16d1c2017-05-23 11:16:52 +0530780 if (!record->compressed)
781 return;
782
Kees Cook634f8f52017-03-03 17:35:25 -0800783 /* Only PSTORE_TYPE_DMESG support compression. */
Ankit Kumar4a16d1c2017-05-23 11:16:52 +0530784 if (record->type != PSTORE_TYPE_DMESG) {
Kees Cook634f8f52017-03-03 17:35:25 -0800785 pr_warn("ignored compressed record type %d\n", record->type);
786 return;
787 }
788
789 /* No compression method has created the common buffer. */
790 if (!big_oops_buf) {
791 pr_warn("no decompression buffer allocated\n");
792 return;
793 }
794
795 unzipped_len = pstore_decompress(record->buf, big_oops_buf,
796 record->size, big_oops_buf_sz);
Kees Cook7e8cc8d2017-03-04 22:28:46 -0800797 if (unzipped_len <= 0) {
Kees Cook634f8f52017-03-03 17:35:25 -0800798 pr_err("decompression failed: %d\n", unzipped_len);
Kees Cook7e8cc8d2017-03-04 22:28:46 -0800799 return;
800 }
801
802 /* Build new buffer for decompressed contents. */
803 decompressed = kmalloc(unzipped_len + record->ecc_notice_size,
804 GFP_KERNEL);
805 if (!decompressed) {
806 pr_err("decompression ran out of memory\n");
807 return;
808 }
809 memcpy(decompressed, big_oops_buf, unzipped_len);
810
811 /* Append ECC notice to decompressed buffer. */
812 memcpy(decompressed + unzipped_len, record->buf + record->size,
813 record->ecc_notice_size);
814
815 /* Swap out compresed contents with decompressed contents. */
816 kfree(record->buf);
817 record->buf = decompressed;
818 record->size = unzipped_len;
819 record->compressed = false;
Kees Cook634f8f52017-03-03 17:35:25 -0800820}
821
Tony Luckca01d6d2010-12-28 14:25:21 -0800822/*
Kees Cook3a7d2fd2017-04-27 15:53:21 -0700823 * Read all the records from one persistent store backend. Create
Luck, Tony6dda9262011-08-11 15:14:39 -0700824 * files in our filesystem. Don't warn about -EEXIST errors
825 * when we are re-scanning the backing store looking to add new
826 * error records.
Tony Luckca01d6d2010-12-28 14:25:21 -0800827 */
Kees Cook3a7d2fd2017-04-27 15:53:21 -0700828void pstore_get_backend_records(struct pstore_info *psi,
829 struct dentry *root, int quiet)
Tony Luckca01d6d2010-12-28 14:25:21 -0800830{
Kees Cook2a2b0ac2017-03-04 22:57:26 -0800831 int failed = 0;
Kees Cook656de422017-05-16 12:03:31 -0700832 unsigned int stop_loop = 65536;
Tony Luckca01d6d2010-12-28 14:25:21 -0800833
Kees Cook3a7d2fd2017-04-27 15:53:21 -0700834 if (!psi || !root)
Tony Luckca01d6d2010-12-28 14:25:21 -0800835 return;
836
Kees Cookf6f82852011-11-17 12:58:07 -0800837 mutex_lock(&psi->read_mutex);
Kees Cook2174f6d2011-11-18 13:49:00 -0800838 if (psi->open && psi->open(psi))
Chen Gong06cf91b2011-05-16 11:00:27 -0700839 goto out;
840
Kees Cook1dfff7d2017-03-04 22:46:41 -0800841 /*
842 * Backend callback read() allocates record.buf. decompress_record()
843 * may reallocate record.buf. On success, pstore_mkfile() will keep
844 * the record.buf, so free it only on failure.
845 */
Kees Cook656de422017-05-16 12:03:31 -0700846 for (; stop_loop; stop_loop--) {
Kees Cook2a2b0ac2017-03-04 22:57:26 -0800847 struct pstore_record *record;
848 int rc;
849
850 record = kzalloc(sizeof(*record), GFP_KERNEL);
851 if (!record) {
852 pr_err("out of memory creating record\n");
853 break;
854 }
Kees Cooke581ca82017-05-19 15:10:31 -0700855 pstore_record_init(record, psi);
Kees Cook2a2b0ac2017-03-04 22:57:26 -0800856
857 record->size = psi->read(record);
858
859 /* No more records left in backend? */
Douglas Andersonf6525b92017-05-30 15:50:38 -0700860 if (record->size <= 0) {
861 kfree(record);
Kees Cook2a2b0ac2017-03-04 22:57:26 -0800862 break;
Douglas Andersonf6525b92017-05-30 15:50:38 -0700863 }
Kees Cook2a2b0ac2017-03-04 22:57:26 -0800864
865 decompress_record(record);
Kees Cook3a7d2fd2017-04-27 15:53:21 -0700866 rc = pstore_mkfile(root, record);
Kees Cook1dfff7d2017-03-04 22:46:41 -0800867 if (rc) {
Kees Cook83f70f02017-03-04 23:12:24 -0800868 /* pstore_mkfile() did not take record, so free it. */
Kees Cook2a2b0ac2017-03-04 22:57:26 -0800869 kfree(record->buf);
Kees Cook83f70f02017-03-04 23:12:24 -0800870 kfree(record);
Kees Cook1dfff7d2017-03-04 22:46:41 -0800871 if (rc != -EEXIST || !quiet)
872 failed++;
873 }
Tony Luckca01d6d2010-12-28 14:25:21 -0800874 }
Kees Cook2174f6d2011-11-18 13:49:00 -0800875 if (psi->close)
876 psi->close(psi);
Chen Gong06cf91b2011-05-16 11:00:27 -0700877out:
Kees Cookf6f82852011-11-17 12:58:07 -0800878 mutex_unlock(&psi->read_mutex);
Tony Luckca01d6d2010-12-28 14:25:21 -0800879
880 if (failed)
Kees Cook656de422017-05-16 12:03:31 -0700881 pr_warn("failed to create %d record(s) from '%s'\n",
Fabian Frederickef748852014-06-06 14:37:31 -0700882 failed, psi->name);
Kees Cook656de422017-05-16 12:03:31 -0700883 if (!stop_loop)
884 pr_err("looping? Too many records seen from '%s'\n",
885 psi->name);
Tony Luckca01d6d2010-12-28 14:25:21 -0800886}
887
Luck, Tony6dda9262011-08-11 15:14:39 -0700888static void pstore_dowork(struct work_struct *work)
889{
890 pstore_get_records(1);
891}
892
Kees Cook24ed9602017-08-28 11:28:21 -0700893static void pstore_timefunc(struct timer_list *unused)
Luck, Tony6dda9262011-08-11 15:14:39 -0700894{
895 if (pstore_new_entry) {
896 pstore_new_entry = 0;
897 schedule_work(&pstore_work);
898 }
899
Kees Cook6330d552017-03-06 12:42:12 -0800900 if (pstore_update_ms >= 0)
901 mod_timer(&pstore_timer,
902 jiffies + msecs_to_jiffies(pstore_update_ms));
Luck, Tony6dda9262011-08-11 15:14:39 -0700903}
904
Matthew Garrettdee28e72011-07-21 16:57:55 -0400905module_param(backend, charp, 0444);
906MODULE_PARM_DESC(backend, "Pstore backend to use");