blob: 327ee70e881dcfe29cf6a12490a0875614aacbf5 [file] [log] [blame]
Thomas Gleixner45051532019-05-29 16:57:47 -07001// SPDX-License-Identifier: GPL-2.0-only
Tony Luckca01d6d2010-12-28 14:25:21 -08002/*
3 * Persistent Storage - platform driver interface parts.
4 *
Anton Vorontsovf29e5952012-05-26 06:20:19 -07005 * Copyright (C) 2007-2008 Google, Inc.
Tony Luckca01d6d2010-12-28 14:25:21 -08006 * Copyright (C) 2010 Intel Corporation <tony.luck@intel.com>
Tony Luckca01d6d2010-12-28 14:25:21 -08007 */
8
Fabian Frederickef748852014-06-06 14:37:31 -07009#define pr_fmt(fmt) "pstore: " fmt
10
Tony Luckca01d6d2010-12-28 14:25:21 -080011#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>
Anton Vorontsovf29e5952012-05-26 06:20:19 -070016#include <linux/console.h>
Tony Luckca01d6d2010-12-28 14:25:21 -080017#include <linux/module.h>
18#include <linux/pstore.h>
Arnd Bergmann58eb5b672018-03-15 16:34:08 +010019#if IS_ENABLED(CONFIG_PSTORE_LZO_COMPRESS)
Geliang Tang8cfc8dd2016-02-18 22:04:22 +080020#include <linux/lzo.h>
21#endif
Arnd Bergmann58eb5b672018-03-15 16:34:08 +010022#if IS_ENABLED(CONFIG_PSTORE_LZ4_COMPRESS) || IS_ENABLED(CONFIG_PSTORE_LZ4HC_COMPRESS)
Geliang Tang8cfc8dd2016-02-18 22:04:22 +080023#include <linux/lz4.h>
24#endif
Geliang Tang1021bcf2018-08-01 19:23:37 +080025#if IS_ENABLED(CONFIG_PSTORE_ZSTD_COMPRESS)
26#include <linux/zstd.h>
27#endif
Geliang Tangcb3bee02018-03-09 18:51:07 +080028#include <linux/crypto.h>
Tony Luckca01d6d2010-12-28 14:25:21 -080029#include <linux/string.h>
Luck, Tony6dda9262011-08-11 15:14:39 -070030#include <linux/timer.h>
Tony Luckca01d6d2010-12-28 14:25:21 -080031#include <linux/slab.h>
32#include <linux/uaccess.h>
Anton Vorontsova3f5f072012-05-26 06:20:28 -070033#include <linux/jiffies.h>
Luck, Tony6dda9262011-08-11 15:14:39 -070034#include <linux/workqueue.h>
Tony Luckca01d6d2010-12-28 14:25:21 -080035
36#include "internal.h"
37
38/*
Luck, Tony6dda9262011-08-11 15:14:39 -070039 * We defer making "oops" entries appear in pstore - see
40 * whether the system is actually still running well enough
41 * to let someone see the entry
42 */
Anton Vorontsov521f72882012-05-26 06:20:29 -070043static int pstore_update_ms = -1;
Anton Vorontsova3f5f072012-05-26 06:20:28 -070044module_param_named(update_ms, pstore_update_ms, int, 0600);
45MODULE_PARM_DESC(update_ms, "milliseconds before pstore updates its content "
Anton Vorontsov521f72882012-05-26 06:20:29 -070046 "(default is -1, which means runtime updates are disabled; "
Kees Cook78c83c82020-05-05 21:36:15 -070047 "enabling this option may not be safe; it may lead to further "
Anton Vorontsov521f72882012-05-26 06:20:29 -070048 "corruption on Oopses)");
Luck, Tony6dda9262011-08-11 15:14:39 -070049
Joel Fernandes (Google)f0f23e52018-11-03 16:38:16 -070050/* Names should be in the same order as the enum pstore_type_id */
51static const char * const pstore_type_names[] = {
52 "dmesg",
53 "mce",
54 "console",
55 "ftrace",
56 "rtas",
57 "powerpc-ofw",
58 "powerpc-common",
59 "pmsg",
60 "powerpc-opal",
61};
62
Luck, Tony6dda9262011-08-11 15:14:39 -070063static int pstore_new_entry;
64
Kees Cook24ed9602017-08-28 11:28:21 -070065static void pstore_timefunc(struct timer_list *);
Kees Cook1d27e3e2017-10-04 16:27:04 -070066static DEFINE_TIMER(pstore_timer, pstore_timefunc);
Luck, Tony6dda9262011-08-11 15:14:39 -070067
68static void pstore_dowork(struct work_struct *);
69static DECLARE_WORK(pstore_work, pstore_dowork);
70
71/*
Kees Cook6248a0662020-05-04 19:33:54 -070072 * psinfo_lock protects "psinfo" during calls to
73 * pstore_register(), pstore_unregister(), and
74 * the filesystem mount/unmount routines.
Tony Luckca01d6d2010-12-28 14:25:21 -080075 */
Kees Cookcab12fd2020-05-04 19:31:36 -070076static DEFINE_MUTEX(psinfo_lock);
Anton Vorontsov060287b2012-07-09 17:10:41 -070077struct pstore_info *psinfo;
Tony Luckca01d6d2010-12-28 14:25:21 -080078
Matthew Garrettdee28e72011-07-21 16:57:55 -040079static char *backend;
Kees Cookfe1d4752018-03-06 15:57:38 -080080static char *compress =
81#ifdef CONFIG_PSTORE_COMPRESS_DEFAULT
82 CONFIG_PSTORE_COMPRESS_DEFAULT;
83#else
84 NULL;
85#endif
Matthew Garrettdee28e72011-07-21 16:57:55 -040086
Aruna Balakrishnaiahb0aad7a2013-08-16 13:53:10 -070087/* Compression parameters */
Geliang Tangcb3bee02018-03-09 18:51:07 +080088static struct crypto_comp *tfm;
Geliang Tang8cfc8dd2016-02-18 22:04:22 +080089
90struct pstore_zbackend {
Geliang Tangcb3bee02018-03-09 18:51:07 +080091 int (*zbufsize)(size_t size);
Geliang Tang8cfc8dd2016-02-18 22:04:22 +080092 const char *name;
93};
Aruna Balakrishnaiahb0aad7a2013-08-16 13:53:10 -070094
95static char *big_oops_buf;
96static size_t big_oops_buf_sz;
97
Luck, Tony366f7e72011-03-18 15:33:43 -070098/* How much of the console log to snapshot */
David Howells349d7432017-07-05 16:24:34 +010099unsigned long kmsg_bytes = PSTORE_DEFAULT_KMSG_BYTES;
Tony Luckca01d6d2010-12-28 14:25:21 -0800100
Luck, Tony366f7e72011-03-18 15:33:43 -0700101void pstore_set_kmsg_bytes(int bytes)
Tony Luckca01d6d2010-12-28 14:25:21 -0800102{
Luck, Tony366f7e72011-03-18 15:33:43 -0700103 kmsg_bytes = bytes;
Tony Luckca01d6d2010-12-28 14:25:21 -0800104}
105
Tony Luckca01d6d2010-12-28 14:25:21 -0800106/* Tag each group of saved records with a sequence number */
107static int oopscount;
108
Joel Fernandes (Google)f0f23e52018-11-03 16:38:16 -0700109const char *pstore_type_to_name(enum pstore_type_id type)
110{
111 BUILD_BUG_ON(ARRAY_SIZE(pstore_type_names) != PSTORE_TYPE_MAX);
112
113 if (WARN_ON_ONCE(type >= PSTORE_TYPE_MAX))
114 return "unknown";
115
116 return pstore_type_names[type];
117}
118EXPORT_SYMBOL_GPL(pstore_type_to_name);
119
120enum pstore_type_id pstore_name_to_type(const char *name)
121{
122 int i;
123
124 for (i = 0; i < PSTORE_TYPE_MAX; i++) {
125 if (!strcmp(pstore_type_names[i], name))
126 return i;
127 }
128
129 return PSTORE_TYPE_MAX;
130}
131EXPORT_SYMBOL_GPL(pstore_name_to_type);
132
Seiji Aguchi381b8722012-03-16 15:36:59 -0700133static const char *get_reason_str(enum kmsg_dump_reason reason)
134{
135 switch (reason) {
136 case KMSG_DUMP_PANIC:
137 return "Panic";
138 case KMSG_DUMP_OOPS:
139 return "Oops";
140 case KMSG_DUMP_EMERG:
141 return "Emergency";
142 case KMSG_DUMP_RESTART:
143 return "Restart";
144 case KMSG_DUMP_HALT:
145 return "Halt";
146 case KMSG_DUMP_POWEROFF:
147 return "Poweroff";
148 default:
149 return "Unknown";
150 }
151}
Tony Luck9f6af272011-03-22 16:01:49 -0700152
Kees Cook78c83c82020-05-05 21:36:15 -0700153static void pstore_timer_kick(void)
154{
155 if (pstore_update_ms < 0)
156 return;
157
158 mod_timer(&pstore_timer, jiffies + msecs_to_jiffies(pstore_update_ms));
159}
160
Kees Cookea84b582018-11-30 14:36:58 -0800161/*
162 * Should pstore_dump() wait for a concurrent pstore_dump()? If
163 * not, the current pstore_dump() will report a failure to dump
164 * and return.
165 */
166static bool pstore_cannot_wait(enum kmsg_dump_reason reason)
Seiji Aguchi9f244e92013-01-11 18:09:41 +0000167{
Kees Cookea84b582018-11-30 14:36:58 -0800168 /* In NMI path, pstore shouldn't block regardless of reason. */
Seiji Aguchi9f244e92013-01-11 18:09:41 +0000169 if (in_nmi())
170 return true;
171
172 switch (reason) {
173 /* In panic case, other cpus are stopped by smp_send_stop(). */
174 case KMSG_DUMP_PANIC:
Kees Cookea84b582018-11-30 14:36:58 -0800175 /* Emergency restart shouldn't be blocked. */
Seiji Aguchi9f244e92013-01-11 18:09:41 +0000176 case KMSG_DUMP_EMERG:
177 return true;
178 default:
179 return false;
180 }
181}
Seiji Aguchi9f244e92013-01-11 18:09:41 +0000182
Arnd Bergmann58eb5b672018-03-15 16:34:08 +0100183#if IS_ENABLED(CONFIG_PSTORE_DEFLATE_COMPRESS)
Geliang Tangcb3bee02018-03-09 18:51:07 +0800184static int zbufsize_deflate(size_t size)
Aruna Balakrishnaiahb0aad7a2013-08-16 13:53:10 -0700185{
Aruna Balakrishnaiah7de8fe22013-09-11 10:57:41 -0700186 size_t cmpr;
Aruna Balakrishnaiahb0aad7a2013-08-16 13:53:10 -0700187
Geliang Tangcb3bee02018-03-09 18:51:07 +0800188 switch (size) {
Aruna Balakrishnaiah7de8fe22013-09-11 10:57:41 -0700189 /* buffer range for efivars */
190 case 1000 ... 2000:
191 cmpr = 56;
192 break;
193 case 2001 ... 3000:
194 cmpr = 54;
195 break;
196 case 3001 ... 3999:
197 cmpr = 52;
198 break;
199 /* buffer range for nvram, erst */
200 case 4000 ... 10000:
201 cmpr = 45;
202 break;
203 default:
204 cmpr = 60;
205 break;
206 }
207
Geliang Tangcb3bee02018-03-09 18:51:07 +0800208 return (size * 100) / cmpr;
Geliang Tang8cfc8dd2016-02-18 22:04:22 +0800209}
Geliang Tang8cfc8dd2016-02-18 22:04:22 +0800210#endif
211
Arnd Bergmann58eb5b672018-03-15 16:34:08 +0100212#if IS_ENABLED(CONFIG_PSTORE_LZO_COMPRESS)
Geliang Tangcb3bee02018-03-09 18:51:07 +0800213static int zbufsize_lzo(size_t size)
Geliang Tang8cfc8dd2016-02-18 22:04:22 +0800214{
Geliang Tangcb3bee02018-03-09 18:51:07 +0800215 return lzo1x_worst_compress(size);
Geliang Tang8cfc8dd2016-02-18 22:04:22 +0800216}
Geliang Tang8cfc8dd2016-02-18 22:04:22 +0800217#endif
218
Arnd Bergmann58eb5b672018-03-15 16:34:08 +0100219#if IS_ENABLED(CONFIG_PSTORE_LZ4_COMPRESS) || IS_ENABLED(CONFIG_PSTORE_LZ4HC_COMPRESS)
Geliang Tangcb3bee02018-03-09 18:51:07 +0800220static int zbufsize_lz4(size_t size)
Geliang Tang8cfc8dd2016-02-18 22:04:22 +0800221{
Geliang Tangcb3bee02018-03-09 18:51:07 +0800222 return LZ4_compressBound(size);
Geliang Tang239b7162018-02-13 14:40:39 +0800223}
Geliang Tang239b7162018-02-13 14:40:39 +0800224#endif
225
Arnd Bergmann58eb5b672018-03-15 16:34:08 +0100226#if IS_ENABLED(CONFIG_PSTORE_842_COMPRESS)
Geliang Tangcb3bee02018-03-09 18:51:07 +0800227static int zbufsize_842(size_t size)
Geliang Tang239b7162018-02-13 14:40:39 +0800228{
Kees Cook55597402018-03-06 15:15:24 -0800229 return size;
Geliang Tang239b7162018-02-13 14:40:39 +0800230}
Kees Cookfe1d4752018-03-06 15:57:38 -0800231#endif
Geliang Tang8cfc8dd2016-02-18 22:04:22 +0800232
Geliang Tang1021bcf2018-08-01 19:23:37 +0800233#if IS_ENABLED(CONFIG_PSTORE_ZSTD_COMPRESS)
234static int zbufsize_zstd(size_t size)
235{
236 return ZSTD_compressBound(size);
237}
238#endif
239
Kees Cookfe1d4752018-03-06 15:57:38 -0800240static const struct pstore_zbackend *zbackend __ro_after_init;
241
242static const struct pstore_zbackend zbackends[] = {
Arnd Bergmann58eb5b672018-03-15 16:34:08 +0100243#if IS_ENABLED(CONFIG_PSTORE_DEFLATE_COMPRESS)
Kees Cookfe1d4752018-03-06 15:57:38 -0800244 {
Geliang Tangcb3bee02018-03-09 18:51:07 +0800245 .zbufsize = zbufsize_deflate,
246 .name = "deflate",
Kees Cookfe1d4752018-03-06 15:57:38 -0800247 },
248#endif
Arnd Bergmann58eb5b672018-03-15 16:34:08 +0100249#if IS_ENABLED(CONFIG_PSTORE_LZO_COMPRESS)
Kees Cookfe1d4752018-03-06 15:57:38 -0800250 {
Geliang Tangcb3bee02018-03-09 18:51:07 +0800251 .zbufsize = zbufsize_lzo,
Kees Cookfe1d4752018-03-06 15:57:38 -0800252 .name = "lzo",
253 },
254#endif
Arnd Bergmann58eb5b672018-03-15 16:34:08 +0100255#if IS_ENABLED(CONFIG_PSTORE_LZ4_COMPRESS)
Kees Cookfe1d4752018-03-06 15:57:38 -0800256 {
Geliang Tangcb3bee02018-03-09 18:51:07 +0800257 .zbufsize = zbufsize_lz4,
Kees Cookfe1d4752018-03-06 15:57:38 -0800258 .name = "lz4",
259 },
260#endif
Arnd Bergmann58eb5b672018-03-15 16:34:08 +0100261#if IS_ENABLED(CONFIG_PSTORE_LZ4HC_COMPRESS)
Kees Cookfe1d4752018-03-06 15:57:38 -0800262 {
Geliang Tangcb3bee02018-03-09 18:51:07 +0800263 .zbufsize = zbufsize_lz4,
Kees Cookfe1d4752018-03-06 15:57:38 -0800264 .name = "lz4hc",
265 },
266#endif
Arnd Bergmann58eb5b672018-03-15 16:34:08 +0100267#if IS_ENABLED(CONFIG_PSTORE_842_COMPRESS)
Kees Cookfe1d4752018-03-06 15:57:38 -0800268 {
Geliang Tangcb3bee02018-03-09 18:51:07 +0800269 .zbufsize = zbufsize_842,
Kees Cookfe1d4752018-03-06 15:57:38 -0800270 .name = "842",
271 },
272#endif
Geliang Tang1021bcf2018-08-01 19:23:37 +0800273#if IS_ENABLED(CONFIG_PSTORE_ZSTD_COMPRESS)
274 {
275 .zbufsize = zbufsize_zstd,
276 .name = "zstd",
277 },
278#endif
Kees Cookfe1d4752018-03-06 15:57:38 -0800279 { }
Geliang Tang8cfc8dd2016-02-18 22:04:22 +0800280};
Geliang Tang8cfc8dd2016-02-18 22:04:22 +0800281
282static int pstore_compress(const void *in, void *out,
Geliang Tangcb3bee02018-03-09 18:51:07 +0800283 unsigned int inlen, unsigned int outlen)
Geliang Tang8cfc8dd2016-02-18 22:04:22 +0800284{
Geliang Tangcb3bee02018-03-09 18:51:07 +0800285 int ret;
286
287 ret = crypto_comp_compress(tfm, in, inlen, out, &outlen);
288 if (ret) {
289 pr_err("crypto_comp_compress failed, ret = %d!\n", ret);
290 return ret;
291 }
292
293 return outlen;
Geliang Tang8cfc8dd2016-02-18 22:04:22 +0800294}
295
Geliang Tang8cfc8dd2016-02-18 22:04:22 +0800296static void allocate_buf_for_compression(void)
297{
Kees Cook95047b02018-10-17 14:00:12 -0700298 struct crypto_comp *ctx;
299 int size;
300 char *buf;
301
302 /* Skip if not built-in or compression backend not selected yet. */
Tobias Regnerye698aaf2018-04-06 09:25:17 +0200303 if (!IS_ENABLED(CONFIG_PSTORE_COMPRESS) || !zbackend)
Geliang Tangcb3bee02018-03-09 18:51:07 +0800304 return;
305
Kees Cook95047b02018-10-17 14:00:12 -0700306 /* Skip if no pstore backend yet or compression init already done. */
307 if (!psinfo || tfm)
308 return;
309
Geliang Tangcb3bee02018-03-09 18:51:07 +0800310 if (!crypto_has_comp(zbackend->name, 0, 0)) {
Kees Cook95047b02018-10-17 14:00:12 -0700311 pr_err("Unknown compression: %s\n", zbackend->name);
Geliang Tangcb3bee02018-03-09 18:51:07 +0800312 return;
313 }
314
Kees Cook95047b02018-10-17 14:00:12 -0700315 size = zbackend->zbufsize(psinfo->bufsize);
316 if (size <= 0) {
317 pr_err("Invalid compression size for %s: %d\n",
318 zbackend->name, size);
Geliang Tangcb3bee02018-03-09 18:51:07 +0800319 return;
320 }
321
Kees Cook95047b02018-10-17 14:00:12 -0700322 buf = kmalloc(size, GFP_KERNEL);
323 if (!buf) {
324 pr_err("Failed %d byte compression buffer allocation for: %s\n",
325 size, zbackend->name);
Geliang Tangcb3bee02018-03-09 18:51:07 +0800326 return;
Geliang Tang8cfc8dd2016-02-18 22:04:22 +0800327 }
Kees Cook95047b02018-10-17 14:00:12 -0700328
329 ctx = crypto_alloc_comp(zbackend->name, 0, 0);
330 if (IS_ERR_OR_NULL(ctx)) {
331 kfree(buf);
332 pr_err("crypto_alloc_comp('%s') failed: %ld\n", zbackend->name,
333 PTR_ERR(ctx));
334 return;
335 }
336
337 /* A non-NULL big_oops_buf indicates compression is available. */
338 tfm = ctx;
339 big_oops_buf_sz = size;
340 big_oops_buf = buf;
341
Kees Cook0eed84f2018-11-01 14:03:07 -0700342 pr_info("Using crash dump compression: %s\n", zbackend->name);
Geliang Tang8cfc8dd2016-02-18 22:04:22 +0800343}
344
345static void free_buf_for_compression(void)
346{
Pi-Hsun Shiha9fb94a2019-05-20 14:51:19 +0800347 if (IS_ENABLED(CONFIG_PSTORE_COMPRESS) && tfm) {
Geliang Tangcb3bee02018-03-09 18:51:07 +0800348 crypto_free_comp(tfm);
Pi-Hsun Shiha9fb94a2019-05-20 14:51:19 +0800349 tfm = NULL;
350 }
Geliang Tangcb3bee02018-03-09 18:51:07 +0800351 kfree(big_oops_buf);
352 big_oops_buf = NULL;
353 big_oops_buf_sz = 0;
Geliang Tangee1d2672015-10-20 00:39:03 -0700354}
355
Aruna Balakrishnaiahb0aad7a2013-08-16 13:53:10 -0700356/*
357 * Called when compression fails, since the printk buffer
358 * would be fetched for compression calling it again when
359 * compression fails would have moved the iterator of
360 * printk buffer which results in fetching old contents.
361 * Copy the recent messages from big_oops_buf to psinfo->buf
362 */
363static size_t copy_kmsg_to_buffer(int hsize, size_t len)
364{
365 size_t total_len;
366 size_t diff;
367
368 total_len = hsize + len;
369
370 if (total_len > psinfo->bufsize) {
371 diff = total_len - psinfo->bufsize + hsize;
372 memcpy(psinfo->buf, big_oops_buf, hsize);
373 memcpy(psinfo->buf + hsize, big_oops_buf + diff,
374 psinfo->bufsize - hsize);
375 total_len = psinfo->bufsize;
376 } else
377 memcpy(psinfo->buf, big_oops_buf, total_len);
378
379 return total_len;
380}
381
Kees Cooke581ca82017-05-19 15:10:31 -0700382void pstore_record_init(struct pstore_record *record,
383 struct pstore_info *psinfo)
384{
385 memset(record, 0, sizeof(*record));
386
387 record->psi = psinfo;
Kees Cookc7f3c5952017-05-19 15:29:10 -0700388
389 /* Report zeroed timestamp if called before timekeeping has resumed. */
Kees Cook7aaa8222018-05-14 15:50:52 -0700390 record->time = ns_to_timespec64(ktime_get_real_fast_ns());
Kees Cooke581ca82017-05-19 15:10:31 -0700391}
392
Tony Luckca01d6d2010-12-28 14:25:21 -0800393/*
Kees Cook0eed84f2018-11-01 14:03:07 -0700394 * callback from kmsg_dump. Save as much as we can (up to kmsg_bytes) from the
395 * end of the buffer.
Tony Luckca01d6d2010-12-28 14:25:21 -0800396 */
397static void pstore_dump(struct kmsg_dumper *dumper,
Kay Sieverse2ae7152012-06-15 14:07:51 +0200398 enum kmsg_dump_reason reason)
Tony Luckca01d6d2010-12-28 14:25:21 -0800399{
Kay Sieverse2ae7152012-06-15 14:07:51 +0200400 unsigned long total = 0;
Seiji Aguchi381b8722012-03-16 15:36:59 -0700401 const char *why;
Matthew Garrettb94fdd02011-07-21 16:57:54 -0400402 unsigned int part = 1;
Kay Sieverse2ae7152012-06-15 14:07:51 +0200403 int ret;
Tony Luckca01d6d2010-12-28 14:25:21 -0800404
Seiji Aguchi381b8722012-03-16 15:36:59 -0700405 why = get_reason_str(reason);
Tony Luck9f6af272011-03-22 16:01:49 -0700406
Kees Cookea84b582018-11-30 14:36:58 -0800407 if (down_trylock(&psinfo->buf_lock)) {
408 /* Failed to acquire lock: give up if we cannot wait. */
409 if (pstore_cannot_wait(reason)) {
410 pr_err("dump skipped in %s path: may corrupt error record\n",
411 in_nmi() ? "NMI" : why);
Li Pengcheng959217c82016-11-05 10:15:59 +0800412 return;
Seiji Aguchi9f244e92013-01-11 18:09:41 +0000413 }
Kees Cookea84b582018-11-30 14:36:58 -0800414 if (down_interruptible(&psinfo->buf_lock)) {
415 pr_err("could not grab semaphore?!\n");
416 return;
417 }
Namhyung Kim98e44fda2016-05-18 21:00:05 +0900418 }
Kees Cookea84b582018-11-30 14:36:58 -0800419
Tony Luckca01d6d2010-12-28 14:25:21 -0800420 oopscount++;
421 while (total < kmsg_bytes) {
Kay Sieverse2ae7152012-06-15 14:07:51 +0200422 char *dst;
Kees Cook76cc9582017-03-03 23:28:53 -0800423 size_t dst_size;
424 int header_size;
Aruna Balakrishnaiahb0aad7a2013-08-16 13:53:10 -0700425 int zipped_len = -1;
Kees Cook76cc9582017-03-03 23:28:53 -0800426 size_t dump_size;
Kees Cooke581ca82017-05-19 15:10:31 -0700427 struct pstore_record record;
428
429 pstore_record_init(&record, psinfo);
430 record.type = PSTORE_TYPE_DMESG;
431 record.count = oopscount;
432 record.reason = reason;
433 record.part = part;
434 record.buf = psinfo->buf;
Kay Sieverse2ae7152012-06-15 14:07:51 +0200435
Kees Cookea84b582018-11-30 14:36:58 -0800436 if (big_oops_buf) {
Aruna Balakrishnaiahb0aad7a2013-08-16 13:53:10 -0700437 dst = big_oops_buf;
Kees Cook76cc9582017-03-03 23:28:53 -0800438 dst_size = big_oops_buf_sz;
Namhyung Kim235f6d12016-05-18 21:00:06 +0900439 } else {
440 dst = psinfo->buf;
Kees Cook76cc9582017-03-03 23:28:53 -0800441 dst_size = psinfo->bufsize;
Namhyung Kim235f6d12016-05-18 21:00:06 +0900442 }
Tony Luckca01d6d2010-12-28 14:25:21 -0800443
Kees Cook76cc9582017-03-03 23:28:53 -0800444 /* Write dump header. */
445 header_size = snprintf(dst, dst_size, "%s#%d Part%u\n", why,
446 oopscount, part);
447 dst_size -= header_size;
Aruna Balakrishnaiahb0aad7a2013-08-16 13:53:10 -0700448
Kees Cook76cc9582017-03-03 23:28:53 -0800449 /* Write dump contents. */
450 if (!kmsg_dump_get_buffer(dumper, true, dst + header_size,
451 dst_size, &dump_size))
Namhyung Kim235f6d12016-05-18 21:00:06 +0900452 break;
453
Kees Cookea84b582018-11-30 14:36:58 -0800454 if (big_oops_buf) {
Aruna Balakrishnaiahb0aad7a2013-08-16 13:53:10 -0700455 zipped_len = pstore_compress(dst, psinfo->buf,
Kees Cook76cc9582017-03-03 23:28:53 -0800456 header_size + dump_size,
457 psinfo->bufsize);
Aruna Balakrishnaiahb0aad7a2013-08-16 13:53:10 -0700458
459 if (zipped_len > 0) {
Kees Cook76cc9582017-03-03 23:28:53 -0800460 record.compressed = true;
461 record.size = zipped_len;
Aruna Balakrishnaiahb0aad7a2013-08-16 13:53:10 -0700462 } else {
Kees Cook76cc9582017-03-03 23:28:53 -0800463 record.size = copy_kmsg_to_buffer(header_size,
464 dump_size);
Aruna Balakrishnaiahb0aad7a2013-08-16 13:53:10 -0700465 }
466 } else {
Kees Cook76cc9582017-03-03 23:28:53 -0800467 record.size = header_size + dump_size;
Aruna Balakrishnaiahb0aad7a2013-08-16 13:53:10 -0700468 }
Tony Luckca01d6d2010-12-28 14:25:21 -0800469
Kees Cook76cc9582017-03-03 23:28:53 -0800470 ret = psinfo->write(&record);
Kees Cook78c83c82020-05-05 21:36:15 -0700471 if (ret == 0 && reason == KMSG_DUMP_OOPS) {
Luck, Tony6dda9262011-08-11 15:14:39 -0700472 pstore_new_entry = 1;
Kees Cook78c83c82020-05-05 21:36:15 -0700473 pstore_timer_kick();
474 }
Kay Sieverse2ae7152012-06-15 14:07:51 +0200475
Kees Cook76cc9582017-03-03 23:28:53 -0800476 total += record.size;
Matthew Garrett56280682011-07-21 16:57:53 -0400477 part++;
Tony Luckca01d6d2010-12-28 14:25:21 -0800478 }
Kees Cookea84b582018-11-30 14:36:58 -0800479
480 up(&psinfo->buf_lock);
Tony Luckca01d6d2010-12-28 14:25:21 -0800481}
482
483static struct kmsg_dumper pstore_dumper = {
484 .dump = pstore_dump,
485};
486
Geliang Tang306e5c22015-10-31 23:23:15 +0800487/*
488 * Register with kmsg_dump to save last part of console log on panic.
489 */
Geliang Tang18730412015-10-20 00:39:02 -0700490static void pstore_register_kmsg(void)
491{
492 kmsg_dump_register(&pstore_dumper);
493}
494
Geliang Tangee1d2672015-10-20 00:39:03 -0700495static void pstore_unregister_kmsg(void)
496{
497 kmsg_dump_unregister(&pstore_dumper);
498}
499
Anton Vorontsovf29e5952012-05-26 06:20:19 -0700500#ifdef CONFIG_PSTORE_CONSOLE
501static void pstore_console_write(struct console *con, const char *s, unsigned c)
502{
Kees Cookb77fa612018-11-01 14:08:07 -0700503 struct pstore_record record;
Anton Vorontsovf29e5952012-05-26 06:20:19 -0700504
Yue Hu4c6c4d32019-01-31 18:12:46 +0800505 if (!c)
506 return;
507
Kees Cookb77fa612018-11-01 14:08:07 -0700508 pstore_record_init(&record, psinfo);
509 record.type = PSTORE_TYPE_CONSOLE;
Anton Vorontsovf29e5952012-05-26 06:20:19 -0700510
Kees Cookb77fa612018-11-01 14:08:07 -0700511 record.buf = (char *)s;
512 record.size = c;
513 psinfo->write(&record);
Anton Vorontsovf29e5952012-05-26 06:20:19 -0700514}
515
516static struct console pstore_console = {
517 .name = "pstore",
518 .write = pstore_console_write,
519 .flags = CON_PRINTBUFFER | CON_ENABLED | CON_ANYTIME,
520 .index = -1,
521};
522
523static void pstore_register_console(void)
524{
525 register_console(&pstore_console);
526}
Geliang Tangee1d2672015-10-20 00:39:03 -0700527
528static void pstore_unregister_console(void)
529{
530 unregister_console(&pstore_console);
531}
Anton Vorontsovf29e5952012-05-26 06:20:19 -0700532#else
533static void pstore_register_console(void) {}
Geliang Tangee1d2672015-10-20 00:39:03 -0700534static void pstore_unregister_console(void) {}
Anton Vorontsovf29e5952012-05-26 06:20:19 -0700535#endif
536
Kees Cook4c9ec212017-03-05 22:41:10 -0800537static int pstore_write_user_compat(struct pstore_record *record,
538 const char __user *buf)
Mark Salyzyn5bf6d1b2016-09-01 08:13:46 -0700539{
Kees Cook30800d92017-03-07 13:57:11 -0800540 int ret = 0;
Mark Salyzyn5bf6d1b2016-09-01 08:13:46 -0700541
Kees Cook30800d92017-03-07 13:57:11 -0800542 if (record->buf)
543 return -EINVAL;
Mark Salyzyn5bf6d1b2016-09-01 08:13:46 -0700544
Geliang Tang077090a2017-04-29 09:45:16 +0800545 record->buf = memdup_user(buf, record->size);
Hirofumi Nakagawadfd6fa32017-09-26 03:21:27 +0900546 if (IS_ERR(record->buf)) {
Geliang Tang077090a2017-04-29 09:45:16 +0800547 ret = PTR_ERR(record->buf);
Kees Cook30800d92017-03-07 13:57:11 -0800548 goto out;
Mark Salyzyn5bf6d1b2016-09-01 08:13:46 -0700549 }
Kees Cook30800d92017-03-07 13:57:11 -0800550
551 ret = record->psi->write(record);
552
Kees Cook30800d92017-03-07 13:57:11 -0800553 kfree(record->buf);
Geliang Tang077090a2017-04-29 09:45:16 +0800554out:
Kees Cook30800d92017-03-07 13:57:11 -0800555 record->buf = NULL;
556
557 return unlikely(ret < 0) ? ret : record->size;
Mark Salyzyn5bf6d1b2016-09-01 08:13:46 -0700558}
559
Tony Luckca01d6d2010-12-28 14:25:21 -0800560/*
561 * platform specific persistent storage driver registers with
562 * us here. If pstore is already mounted, call the platform
563 * read function right away to populate the file system. If not
564 * then the pstore mount code will call us later to fill out
565 * the file system.
Tony Luckca01d6d2010-12-28 14:25:21 -0800566 */
567int pstore_register(struct pstore_info *psi)
568{
Kees Cook0d7cd092017-03-03 12:11:40 -0800569 if (backend && strcmp(backend, psi->name)) {
570 pr_warn("ignoring unexpected backend '%s'\n", psi->name);
Lenny Szubowicz8e48b1a2013-06-28 17:11:33 -0400571 return -EPERM;
Kees Cook0d7cd092017-03-03 12:11:40 -0800572 }
Lenny Szubowicz8e48b1a2013-06-28 17:11:33 -0400573
Kees Cook4c9ec212017-03-05 22:41:10 -0800574 /* Sanity check flags. */
575 if (!psi->flags) {
576 pr_warn("backend '%s' must support at least one frontend\n",
577 psi->name);
578 return -EINVAL;
579 }
580
581 /* Check for required functions. */
582 if (!psi->read || !psi->write) {
583 pr_warn("backend '%s' must implement read() and write()\n",
584 psi->name);
585 return -EINVAL;
586 }
587
Kees Cookcab12fd2020-05-04 19:31:36 -0700588 mutex_lock(&psinfo_lock);
Tony Luckca01d6d2010-12-28 14:25:21 -0800589 if (psinfo) {
Kees Cook0d7cd092017-03-03 12:11:40 -0800590 pr_warn("backend '%s' already loaded: ignoring '%s'\n",
591 psinfo->name, psi->name);
Kees Cookcab12fd2020-05-04 19:31:36 -0700592 mutex_unlock(&psinfo_lock);
Tony Luckca01d6d2010-12-28 14:25:21 -0800593 return -EBUSY;
594 }
Matthew Garrettdee28e72011-07-21 16:57:55 -0400595
Kees Cook4c9ec212017-03-05 22:41:10 -0800596 if (!psi->write_user)
597 psi->write_user = pstore_write_user_compat;
Tony Luckca01d6d2010-12-28 14:25:21 -0800598 psinfo = psi;
Kees Cookf6f82852011-11-17 12:58:07 -0800599 mutex_init(&psinfo->read_mutex);
Kees Cookea84b582018-11-30 14:36:58 -0800600 sema_init(&psinfo->buf_lock, 1);
Tony Luckca01d6d2010-12-28 14:25:21 -0800601
Kees Cook8880fa32019-05-30 23:37:29 -0700602 if (psi->flags & PSTORE_FLAGS_DMESG)
603 allocate_buf_for_compression();
Aruna Balakrishnaiahb0aad7a2013-08-16 13:53:10 -0700604
Kees Cook27e50412020-05-04 19:43:41 -0700605 pstore_get_records(0);
Tony Luckca01d6d2010-12-28 14:25:21 -0800606
Namhyung Kimc950fd62016-07-28 00:08:25 +0900607 if (psi->flags & PSTORE_FLAGS_DMESG)
608 pstore_register_kmsg();
609 if (psi->flags & PSTORE_FLAGS_CONSOLE)
Luck, Tonydf36ac12013-12-18 15:17:10 -0800610 pstore_register_console();
Namhyung Kimc950fd62016-07-28 00:08:25 +0900611 if (psi->flags & PSTORE_FLAGS_FTRACE)
Luck, Tonydf36ac12013-12-18 15:17:10 -0800612 pstore_register_ftrace();
Namhyung Kimc950fd62016-07-28 00:08:25 +0900613 if (psi->flags & PSTORE_FLAGS_PMSG)
Mark Salyzyn9d5438f2015-01-16 16:01:10 -0800614 pstore_register_pmsg();
Tony Luckca01d6d2010-12-28 14:25:21 -0800615
Kees Cook6330d552017-03-06 12:42:12 -0800616 /* Start watching for new records, if desired. */
Kees Cook78c83c82020-05-05 21:36:15 -0700617 pstore_timer_kick();
Luck, Tony6dda9262011-08-11 15:14:39 -0700618
Wang Long42222c22015-05-21 09:34:22 -0700619 /*
620 * Update the module parameter backend, so it is visible
621 * through /sys/module/pstore/parameters/backend
622 */
623 backend = psi->name;
624
Fabian Frederickef748852014-06-06 14:37:31 -0700625 pr_info("Registered %s as persistent store backend\n", psi->name);
Lenny Szubowicz8e48b1a2013-06-28 17:11:33 -0400626
Kees Cook6248a0662020-05-04 19:33:54 -0700627 mutex_unlock(&psinfo_lock);
Tony Luckca01d6d2010-12-28 14:25:21 -0800628 return 0;
629}
630EXPORT_SYMBOL_GPL(pstore_register);
631
Geliang Tangee1d2672015-10-20 00:39:03 -0700632void pstore_unregister(struct pstore_info *psi)
633{
Kees Cook6248a0662020-05-04 19:33:54 -0700634 /* It's okay to unregister nothing. */
635 if (!psi)
636 return;
637
638 mutex_lock(&psinfo_lock);
639
640 /* Only one backend can be registered at a time. */
641 if (WARN_ON(psi != psinfo)) {
642 mutex_unlock(&psinfo_lock);
643 return;
644 }
645
Kees Cook78c83c82020-05-05 21:36:15 -0700646 /* Unregister all callbacks. */
Namhyung Kimc950fd62016-07-28 00:08:25 +0900647 if (psi->flags & PSTORE_FLAGS_PMSG)
Kees Cooka1db8062016-05-19 10:59:03 -0400648 pstore_unregister_pmsg();
Namhyung Kimc950fd62016-07-28 00:08:25 +0900649 if (psi->flags & PSTORE_FLAGS_FTRACE)
Kees Cooka1db8062016-05-19 10:59:03 -0400650 pstore_unregister_ftrace();
Namhyung Kimc950fd62016-07-28 00:08:25 +0900651 if (psi->flags & PSTORE_FLAGS_CONSOLE)
Kees Cooka1db8062016-05-19 10:59:03 -0400652 pstore_unregister_console();
Namhyung Kimc950fd62016-07-28 00:08:25 +0900653 if (psi->flags & PSTORE_FLAGS_DMESG)
654 pstore_unregister_kmsg();
Geliang Tangee1d2672015-10-20 00:39:03 -0700655
Kees Cook78c83c82020-05-05 21:36:15 -0700656 /* Stop timer and make sure all work has finished. */
657 del_timer_sync(&pstore_timer);
658 flush_work(&pstore_work);
659
Geliang Tangee1d2672015-10-20 00:39:03 -0700660 free_buf_for_compression();
661
662 psinfo = NULL;
663 backend = NULL;
Kees Cook6248a0662020-05-04 19:33:54 -0700664 mutex_unlock(&psinfo_lock);
Geliang Tangee1d2672015-10-20 00:39:03 -0700665}
666EXPORT_SYMBOL_GPL(pstore_unregister);
667
Kees Cook634f8f52017-03-03 17:35:25 -0800668static void decompress_record(struct pstore_record *record)
669{
Kees Cookbdabc8e2018-10-26 01:17:07 -0700670 int ret;
Kees Cook634f8f52017-03-03 17:35:25 -0800671 int unzipped_len;
Kees Cookbdabc8e2018-10-26 01:17:07 -0700672 char *unzipped, *workspace;
Kees Cook634f8f52017-03-03 17:35:25 -0800673
Ankit Kumar4a16d1c2017-05-23 11:16:52 +0530674 if (!record->compressed)
675 return;
676
Kees Cook634f8f52017-03-03 17:35:25 -0800677 /* Only PSTORE_TYPE_DMESG support compression. */
Ankit Kumar4a16d1c2017-05-23 11:16:52 +0530678 if (record->type != PSTORE_TYPE_DMESG) {
Kees Cook634f8f52017-03-03 17:35:25 -0800679 pr_warn("ignored compressed record type %d\n", record->type);
680 return;
681 }
682
Kees Cookbdabc8e2018-10-26 01:17:07 -0700683 /* Missing compression buffer means compression was not initialized. */
Kees Cook634f8f52017-03-03 17:35:25 -0800684 if (!big_oops_buf) {
Kees Cookbdabc8e2018-10-26 01:17:07 -0700685 pr_warn("no decompression method initialized!\n");
Kees Cook634f8f52017-03-03 17:35:25 -0800686 return;
687 }
688
Kees Cookbdabc8e2018-10-26 01:17:07 -0700689 /* Allocate enough space to hold max decompression and ECC. */
690 unzipped_len = big_oops_buf_sz;
691 workspace = kmalloc(unzipped_len + record->ecc_notice_size,
692 GFP_KERNEL);
693 if (!workspace)
Kees Cook7e8cc8d2017-03-04 22:28:46 -0800694 return;
Kees Cook7e8cc8d2017-03-04 22:28:46 -0800695
Kees Cookbdabc8e2018-10-26 01:17:07 -0700696 /* After decompression "unzipped_len" is almost certainly smaller. */
697 ret = crypto_comp_decompress(tfm, record->buf, record->size,
698 workspace, &unzipped_len);
699 if (ret) {
700 pr_err("crypto_comp_decompress failed, ret = %d!\n", ret);
701 kfree(workspace);
Kees Cook7e8cc8d2017-03-04 22:28:46 -0800702 return;
703 }
Kees Cook7e8cc8d2017-03-04 22:28:46 -0800704
705 /* Append ECC notice to decompressed buffer. */
Kees Cookbdabc8e2018-10-26 01:17:07 -0700706 memcpy(workspace + unzipped_len, record->buf + record->size,
Kees Cook7e8cc8d2017-03-04 22:28:46 -0800707 record->ecc_notice_size);
708
Kees Cookbdabc8e2018-10-26 01:17:07 -0700709 /* Copy decompressed contents into an minimum-sized allocation. */
710 unzipped = kmemdup(workspace, unzipped_len + record->ecc_notice_size,
711 GFP_KERNEL);
712 kfree(workspace);
713 if (!unzipped)
714 return;
715
716 /* Swap out compressed contents with decompressed contents. */
Kees Cook7e8cc8d2017-03-04 22:28:46 -0800717 kfree(record->buf);
Kees Cookbdabc8e2018-10-26 01:17:07 -0700718 record->buf = unzipped;
Kees Cook7e8cc8d2017-03-04 22:28:46 -0800719 record->size = unzipped_len;
720 record->compressed = false;
Kees Cook634f8f52017-03-03 17:35:25 -0800721}
722
Tony Luckca01d6d2010-12-28 14:25:21 -0800723/*
Kees Cook3a7d2fd2017-04-27 15:53:21 -0700724 * Read all the records from one persistent store backend. Create
Luck, Tony6dda9262011-08-11 15:14:39 -0700725 * files in our filesystem. Don't warn about -EEXIST errors
726 * when we are re-scanning the backing store looking to add new
727 * error records.
Tony Luckca01d6d2010-12-28 14:25:21 -0800728 */
Kees Cook3a7d2fd2017-04-27 15:53:21 -0700729void pstore_get_backend_records(struct pstore_info *psi,
730 struct dentry *root, int quiet)
Tony Luckca01d6d2010-12-28 14:25:21 -0800731{
Kees Cook2a2b0ac2017-03-04 22:57:26 -0800732 int failed = 0;
Kees Cook656de422017-05-16 12:03:31 -0700733 unsigned int stop_loop = 65536;
Tony Luckca01d6d2010-12-28 14:25:21 -0800734
Kees Cook3a7d2fd2017-04-27 15:53:21 -0700735 if (!psi || !root)
Tony Luckca01d6d2010-12-28 14:25:21 -0800736 return;
737
Kees Cookf6f82852011-11-17 12:58:07 -0800738 mutex_lock(&psi->read_mutex);
Kees Cook2174f6d2011-11-18 13:49:00 -0800739 if (psi->open && psi->open(psi))
Chen Gong06cf91b2011-05-16 11:00:27 -0700740 goto out;
741
Kees Cook1dfff7d2017-03-04 22:46:41 -0800742 /*
743 * Backend callback read() allocates record.buf. decompress_record()
744 * may reallocate record.buf. On success, pstore_mkfile() will keep
745 * the record.buf, so free it only on failure.
746 */
Kees Cook656de422017-05-16 12:03:31 -0700747 for (; stop_loop; stop_loop--) {
Kees Cook2a2b0ac2017-03-04 22:57:26 -0800748 struct pstore_record *record;
749 int rc;
750
751 record = kzalloc(sizeof(*record), GFP_KERNEL);
752 if (!record) {
753 pr_err("out of memory creating record\n");
754 break;
755 }
Kees Cooke581ca82017-05-19 15:10:31 -0700756 pstore_record_init(record, psi);
Kees Cook2a2b0ac2017-03-04 22:57:26 -0800757
758 record->size = psi->read(record);
759
760 /* No more records left in backend? */
Douglas Andersonf6525b92017-05-30 15:50:38 -0700761 if (record->size <= 0) {
762 kfree(record);
Kees Cook2a2b0ac2017-03-04 22:57:26 -0800763 break;
Douglas Andersonf6525b92017-05-30 15:50:38 -0700764 }
Kees Cook2a2b0ac2017-03-04 22:57:26 -0800765
766 decompress_record(record);
Kees Cook3a7d2fd2017-04-27 15:53:21 -0700767 rc = pstore_mkfile(root, record);
Kees Cook1dfff7d2017-03-04 22:46:41 -0800768 if (rc) {
Kees Cook83f70f02017-03-04 23:12:24 -0800769 /* pstore_mkfile() did not take record, so free it. */
Kees Cook2a2b0ac2017-03-04 22:57:26 -0800770 kfree(record->buf);
Kees Cook83f70f02017-03-04 23:12:24 -0800771 kfree(record);
Kees Cook1dfff7d2017-03-04 22:46:41 -0800772 if (rc != -EEXIST || !quiet)
773 failed++;
774 }
Tony Luckca01d6d2010-12-28 14:25:21 -0800775 }
Kees Cook2174f6d2011-11-18 13:49:00 -0800776 if (psi->close)
777 psi->close(psi);
Chen Gong06cf91b2011-05-16 11:00:27 -0700778out:
Kees Cookf6f82852011-11-17 12:58:07 -0800779 mutex_unlock(&psi->read_mutex);
Tony Luckca01d6d2010-12-28 14:25:21 -0800780
781 if (failed)
Kees Cook656de422017-05-16 12:03:31 -0700782 pr_warn("failed to create %d record(s) from '%s'\n",
Fabian Frederickef748852014-06-06 14:37:31 -0700783 failed, psi->name);
Kees Cook656de422017-05-16 12:03:31 -0700784 if (!stop_loop)
785 pr_err("looping? Too many records seen from '%s'\n",
786 psi->name);
Tony Luckca01d6d2010-12-28 14:25:21 -0800787}
788
Luck, Tony6dda9262011-08-11 15:14:39 -0700789static void pstore_dowork(struct work_struct *work)
790{
791 pstore_get_records(1);
792}
793
Kees Cook24ed9602017-08-28 11:28:21 -0700794static void pstore_timefunc(struct timer_list *unused)
Luck, Tony6dda9262011-08-11 15:14:39 -0700795{
796 if (pstore_new_entry) {
797 pstore_new_entry = 0;
798 schedule_work(&pstore_work);
799 }
800
Kees Cook78c83c82020-05-05 21:36:15 -0700801 pstore_timer_kick();
Luck, Tony6dda9262011-08-11 15:14:39 -0700802}
803
Ben Dooks (Codethink)8d82cee2019-10-16 13:33:17 +0100804static void __init pstore_choose_compression(void)
Kees Cookfe1d4752018-03-06 15:57:38 -0800805{
806 const struct pstore_zbackend *step;
807
808 if (!compress)
809 return;
810
811 for (step = zbackends; step->name; step++) {
812 if (!strcmp(compress, step->name)) {
813 zbackend = step;
Kees Cookfe1d4752018-03-06 15:57:38 -0800814 return;
815 }
816 }
817}
818
Kees Cookcb095af2018-10-18 11:17:42 -0700819static int __init pstore_init(void)
820{
821 int ret;
822
823 pstore_choose_compression();
824
Joel Fernandes (Google)41603162018-10-17 03:13:55 -0700825 /*
826 * Check if any pstore backends registered earlier but did not
827 * initialize compression because crypto was not ready. If so,
828 * initialize compression now.
829 */
Kees Cook95047b02018-10-17 14:00:12 -0700830 allocate_buf_for_compression();
Joel Fernandes (Google)41603162018-10-17 03:13:55 -0700831
Kees Cookcb095af2018-10-18 11:17:42 -0700832 ret = pstore_init_fs();
833 if (ret)
chenqiwu8a57d6d2020-02-07 17:46:39 +0800834 free_buf_for_compression();
Kees Cookcb095af2018-10-18 11:17:42 -0700835
chenqiwu8a57d6d2020-02-07 17:46:39 +0800836 return ret;
Kees Cookcb095af2018-10-18 11:17:42 -0700837}
Joel Fernandes (Google)41603162018-10-17 03:13:55 -0700838late_initcall(pstore_init);
Kees Cookcb095af2018-10-18 11:17:42 -0700839
840static void __exit pstore_exit(void)
841{
842 pstore_exit_fs();
843}
844module_exit(pstore_exit)
845
Kees Cookfe1d4752018-03-06 15:57:38 -0800846module_param(compress, charp, 0444);
847MODULE_PARM_DESC(compress, "Pstore compression to use");
848
Matthew Garrettdee28e72011-07-21 16:57:55 -0400849module_param(backend, charp, 0444);
850MODULE_PARM_DESC(backend, "Pstore backend to use");
Kees Cookcb095af2018-10-18 11:17:42 -0700851
852MODULE_AUTHOR("Tony Luck <tony.luck@intel.com>");
853MODULE_LICENSE("GPL");