blob: 86d1038b5a1292b464c561ba7086518cdd7eaf80 [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
21#include <linux/atomic.h>
22#include <linux/types.h>
23#include <linux/errno.h>
24#include <linux/init.h>
25#include <linux/kmsg_dump.h>
Anton Vorontsovf29e5952012-05-26 06:20:19 -070026#include <linux/console.h>
Tony Luckca01d6d2010-12-28 14:25:21 -080027#include <linux/module.h>
28#include <linux/pstore.h>
29#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>
Don Zickusabd4d552011-08-12 10:54:51 -070033#include <linux/hardirq.h>
Anton Vorontsova3f5f072012-05-26 06:20:28 -070034#include <linux/jiffies.h>
Luck, Tony6dda9262011-08-11 15:14:39 -070035#include <linux/workqueue.h>
Tony Luckca01d6d2010-12-28 14:25:21 -080036
37#include "internal.h"
38
39/*
Luck, Tony6dda9262011-08-11 15:14:39 -070040 * We defer making "oops" entries appear in pstore - see
41 * whether the system is actually still running well enough
42 * to let someone see the entry
43 */
Anton Vorontsov521f72882012-05-26 06:20:29 -070044static int pstore_update_ms = -1;
Anton Vorontsova3f5f072012-05-26 06:20:28 -070045module_param_named(update_ms, pstore_update_ms, int, 0600);
46MODULE_PARM_DESC(update_ms, "milliseconds before pstore updates its content "
Anton Vorontsov521f72882012-05-26 06:20:29 -070047 "(default is -1, which means runtime updates are disabled; "
48 "enabling this option is not safe, it may lead to further "
49 "corruption on Oopses)");
Luck, Tony6dda9262011-08-11 15:14:39 -070050
51static int pstore_new_entry;
52
53static void pstore_timefunc(unsigned long);
54static DEFINE_TIMER(pstore_timer, pstore_timefunc, 0, 0);
55
56static void pstore_dowork(struct work_struct *);
57static DECLARE_WORK(pstore_work, pstore_dowork);
58
59/*
Tony Luckca01d6d2010-12-28 14:25:21 -080060 * pstore_lock just protects "psinfo" during
61 * calls to pstore_register()
62 */
63static DEFINE_SPINLOCK(pstore_lock);
Anton Vorontsov060287b2012-07-09 17:10:41 -070064struct pstore_info *psinfo;
Tony Luckca01d6d2010-12-28 14:25:21 -080065
Matthew Garrettdee28e72011-07-21 16:57:55 -040066static char *backend;
67
Luck, Tony366f7e72011-03-18 15:33:43 -070068/* How much of the console log to snapshot */
Tony Luckca01d6d2010-12-28 14:25:21 -080069static unsigned long kmsg_bytes = 10240;
70
Luck, Tony366f7e72011-03-18 15:33:43 -070071void pstore_set_kmsg_bytes(int bytes)
Tony Luckca01d6d2010-12-28 14:25:21 -080072{
Luck, Tony366f7e72011-03-18 15:33:43 -070073 kmsg_bytes = bytes;
Tony Luckca01d6d2010-12-28 14:25:21 -080074}
75
Tony Luckca01d6d2010-12-28 14:25:21 -080076/* Tag each group of saved records with a sequence number */
77static int oopscount;
78
Seiji Aguchi381b8722012-03-16 15:36:59 -070079static const char *get_reason_str(enum kmsg_dump_reason reason)
80{
81 switch (reason) {
82 case KMSG_DUMP_PANIC:
83 return "Panic";
84 case KMSG_DUMP_OOPS:
85 return "Oops";
86 case KMSG_DUMP_EMERG:
87 return "Emergency";
88 case KMSG_DUMP_RESTART:
89 return "Restart";
90 case KMSG_DUMP_HALT:
91 return "Halt";
92 case KMSG_DUMP_POWEROFF:
93 return "Poweroff";
94 default:
95 return "Unknown";
96 }
97}
Tony Luck9f6af272011-03-22 16:01:49 -070098
Seiji Aguchi9f244e92013-01-11 18:09:41 +000099bool pstore_cannot_block_path(enum kmsg_dump_reason reason)
100{
101 /*
102 * In case of NMI path, pstore shouldn't be blocked
103 * regardless of reason.
104 */
105 if (in_nmi())
106 return true;
107
108 switch (reason) {
109 /* In panic case, other cpus are stopped by smp_send_stop(). */
110 case KMSG_DUMP_PANIC:
111 /* Emergency restart shouldn't be blocked by spin lock. */
112 case KMSG_DUMP_EMERG:
113 return true;
114 default:
115 return false;
116 }
117}
118EXPORT_SYMBOL_GPL(pstore_cannot_block_path);
119
Tony Luckca01d6d2010-12-28 14:25:21 -0800120/*
121 * callback from kmsg_dump. (s2,l2) has the most recently
122 * written bytes, older bytes are in (s1,l1). Save as much
123 * as we can from the end of the buffer.
124 */
125static void pstore_dump(struct kmsg_dumper *dumper,
Kay Sieverse2ae7152012-06-15 14:07:51 +0200126 enum kmsg_dump_reason reason)
Tony Luckca01d6d2010-12-28 14:25:21 -0800127{
Kay Sieverse2ae7152012-06-15 14:07:51 +0200128 unsigned long total = 0;
Seiji Aguchi381b8722012-03-16 15:36:59 -0700129 const char *why;
Tony Luckca01d6d2010-12-28 14:25:21 -0800130 u64 id;
Matthew Garrettb94fdd02011-07-21 16:57:54 -0400131 unsigned int part = 1;
Don Zickusabd4d552011-08-12 10:54:51 -0700132 unsigned long flags = 0;
133 int is_locked = 0;
Kay Sieverse2ae7152012-06-15 14:07:51 +0200134 int ret;
Tony Luckca01d6d2010-12-28 14:25:21 -0800135
Seiji Aguchi381b8722012-03-16 15:36:59 -0700136 why = get_reason_str(reason);
Tony Luck9f6af272011-03-22 16:01:49 -0700137
Seiji Aguchi9f244e92013-01-11 18:09:41 +0000138 if (pstore_cannot_block_path(reason)) {
139 is_locked = spin_trylock_irqsave(&psinfo->buf_lock, flags);
140 if (!is_locked) {
141 pr_err("pstore dump routine blocked in %s path, may corrupt error record\n"
142 , in_nmi() ? "NMI" : why);
143 }
Don Zickusabd4d552011-08-12 10:54:51 -0700144 } else
145 spin_lock_irqsave(&psinfo->buf_lock, flags);
Tony Luckca01d6d2010-12-28 14:25:21 -0800146 oopscount++;
147 while (total < kmsg_bytes) {
Kay Sieverse2ae7152012-06-15 14:07:51 +0200148 char *dst;
149 unsigned long size;
150 int hsize;
151 size_t len;
152
Tony Luckca01d6d2010-12-28 14:25:21 -0800153 dst = psinfo->buf;
Matthew Garrett56280682011-07-21 16:57:53 -0400154 hsize = sprintf(dst, "%s#%d Part%d\n", why, oopscount, part);
Tony Luckca01d6d2010-12-28 14:25:21 -0800155 size = psinfo->bufsize - hsize;
156 dst += hsize;
157
Kay Sieverse2ae7152012-06-15 14:07:51 +0200158 if (!kmsg_dump_get_buffer(dumper, true, dst, size, &len))
Tony Luckca01d6d2010-12-28 14:25:21 -0800159 break;
160
Kees Cook3d6d8d22011-11-17 13:13:29 -0800161 ret = psinfo->write(PSTORE_TYPE_DMESG, reason, &id, part,
Seiji Aguchi755d4fe2012-11-26 16:07:44 -0800162 oopscount, hsize + len, psinfo);
Chen Gongb238b8f2011-10-12 09:17:24 -0700163 if (ret == 0 && reason == KMSG_DUMP_OOPS && pstore_is_mounted())
Luck, Tony6dda9262011-08-11 15:14:39 -0700164 pstore_new_entry = 1;
Kay Sieverse2ae7152012-06-15 14:07:51 +0200165
166 total += hsize + len;
Matthew Garrett56280682011-07-21 16:57:53 -0400167 part++;
Tony Luckca01d6d2010-12-28 14:25:21 -0800168 }
Seiji Aguchi9f244e92013-01-11 18:09:41 +0000169 if (pstore_cannot_block_path(reason)) {
Don Zickusabd4d552011-08-12 10:54:51 -0700170 if (is_locked)
Seiji Aguchi9f244e92013-01-11 18:09:41 +0000171 spin_unlock_irqrestore(&psinfo->buf_lock, flags);
Don Zickusabd4d552011-08-12 10:54:51 -0700172 } else
173 spin_unlock_irqrestore(&psinfo->buf_lock, flags);
Tony Luckca01d6d2010-12-28 14:25:21 -0800174}
175
176static struct kmsg_dumper pstore_dumper = {
177 .dump = pstore_dump,
178};
179
Anton Vorontsovf29e5952012-05-26 06:20:19 -0700180#ifdef CONFIG_PSTORE_CONSOLE
181static void pstore_console_write(struct console *con, const char *s, unsigned c)
182{
183 const char *e = s + c;
184
185 while (s < e) {
186 unsigned long flags;
Colin Ian King70a6f462012-11-14 11:49:53 +0000187 u64 id;
Anton Vorontsovf29e5952012-05-26 06:20:19 -0700188
189 if (c > psinfo->bufsize)
190 c = psinfo->bufsize;
Chuansheng Liu80c9d032012-09-18 01:43:44 +0800191
192 if (oops_in_progress) {
193 if (!spin_trylock_irqsave(&psinfo->buf_lock, flags))
194 break;
195 } else {
196 spin_lock_irqsave(&psinfo->buf_lock, flags);
197 }
Anton Vorontsovf29e5952012-05-26 06:20:19 -0700198 memcpy(psinfo->buf, s, c);
Seiji Aguchi755d4fe2012-11-26 16:07:44 -0800199 psinfo->write(PSTORE_TYPE_CONSOLE, 0, &id, 0, 0, c, psinfo);
Anton Vorontsovf29e5952012-05-26 06:20:19 -0700200 spin_unlock_irqrestore(&psinfo->buf_lock, flags);
201 s += c;
202 c = e - s;
203 }
204}
205
206static struct console pstore_console = {
207 .name = "pstore",
208 .write = pstore_console_write,
209 .flags = CON_PRINTBUFFER | CON_ENABLED | CON_ANYTIME,
210 .index = -1,
211};
212
213static void pstore_register_console(void)
214{
215 register_console(&pstore_console);
216}
217#else
218static void pstore_register_console(void) {}
219#endif
220
Anton Vorontsov897dba02012-07-09 17:10:40 -0700221static int pstore_write_compat(enum pstore_type_id type,
222 enum kmsg_dump_reason reason,
Seiji Aguchi755d4fe2012-11-26 16:07:44 -0800223 u64 *id, unsigned int part, int count,
Anton Vorontsov897dba02012-07-09 17:10:40 -0700224 size_t size, struct pstore_info *psi)
225{
226 return psi->write_buf(type, reason, id, part, psinfo->buf, size, psi);
227}
228
Tony Luckca01d6d2010-12-28 14:25:21 -0800229/*
230 * platform specific persistent storage driver registers with
231 * us here. If pstore is already mounted, call the platform
232 * read function right away to populate the file system. If not
233 * then the pstore mount code will call us later to fill out
234 * the file system.
235 *
236 * Register with kmsg_dump to save last part of console log on panic.
237 */
238int pstore_register(struct pstore_info *psi)
239{
240 struct module *owner = psi->owner;
241
242 spin_lock(&pstore_lock);
243 if (psinfo) {
244 spin_unlock(&pstore_lock);
245 return -EBUSY;
246 }
Matthew Garrettdee28e72011-07-21 16:57:55 -0400247
248 if (backend && strcmp(backend, psi->name)) {
249 spin_unlock(&pstore_lock);
250 return -EINVAL;
251 }
252
Anton Vorontsov897dba02012-07-09 17:10:40 -0700253 if (!psi->write)
254 psi->write = pstore_write_compat;
Tony Luckca01d6d2010-12-28 14:25:21 -0800255 psinfo = psi;
Kees Cookf6f82852011-11-17 12:58:07 -0800256 mutex_init(&psinfo->read_mutex);
Tony Luckca01d6d2010-12-28 14:25:21 -0800257 spin_unlock(&pstore_lock);
258
259 if (owner && !try_module_get(owner)) {
260 psinfo = NULL;
261 return -EINVAL;
262 }
263
264 if (pstore_is_mounted())
Luck, Tony6dda9262011-08-11 15:14:39 -0700265 pstore_get_records(0);
Tony Luckca01d6d2010-12-28 14:25:21 -0800266
267 kmsg_dump_register(&pstore_dumper);
Anton Vorontsovf29e5952012-05-26 06:20:19 -0700268 pstore_register_console();
Anton Vorontsov65f8c952012-07-17 14:26:15 -0700269 pstore_register_ftrace();
Tony Luckca01d6d2010-12-28 14:25:21 -0800270
Anton Vorontsova3f5f072012-05-26 06:20:28 -0700271 if (pstore_update_ms >= 0) {
272 pstore_timer.expires = jiffies +
273 msecs_to_jiffies(pstore_update_ms);
274 add_timer(&pstore_timer);
275 }
Luck, Tony6dda9262011-08-11 15:14:39 -0700276
Tony Luckca01d6d2010-12-28 14:25:21 -0800277 return 0;
278}
279EXPORT_SYMBOL_GPL(pstore_register);
280
281/*
Luck, Tony6dda9262011-08-11 15:14:39 -0700282 * Read all the records from the persistent store. Create
283 * files in our filesystem. Don't warn about -EEXIST errors
284 * when we are re-scanning the backing store looking to add new
285 * error records.
Tony Luckca01d6d2010-12-28 14:25:21 -0800286 */
Luck, Tony6dda9262011-08-11 15:14:39 -0700287void pstore_get_records(int quiet)
Tony Luckca01d6d2010-12-28 14:25:21 -0800288{
289 struct pstore_info *psi = psinfo;
Kees Cookf6f82852011-11-17 12:58:07 -0800290 char *buf = NULL;
Chen Gong8d38d742011-05-16 10:58:57 -0700291 ssize_t size;
Tony Luckca01d6d2010-12-28 14:25:21 -0800292 u64 id;
Seiji Aguchi755d4fe2012-11-26 16:07:44 -0800293 int count;
Tony Luckca01d6d2010-12-28 14:25:21 -0800294 enum pstore_type_id type;
295 struct timespec time;
Chen Gong06cf91b2011-05-16 11:00:27 -0700296 int failed = 0, rc;
Tony Luckca01d6d2010-12-28 14:25:21 -0800297
298 if (!psi)
299 return;
300
Kees Cookf6f82852011-11-17 12:58:07 -0800301 mutex_lock(&psi->read_mutex);
Kees Cook2174f6d2011-11-18 13:49:00 -0800302 if (psi->open && psi->open(psi))
Chen Gong06cf91b2011-05-16 11:00:27 -0700303 goto out;
304
Seiji Aguchi755d4fe2012-11-26 16:07:44 -0800305 while ((size = psi->read(&id, &type, &count, &time, &buf, psi)) > 0) {
306 rc = pstore_mkfile(type, psi->name, id, count, buf,
307 (size_t)size, time, psi);
Kees Cookf6f82852011-11-17 12:58:07 -0800308 kfree(buf);
309 buf = NULL;
Luck, Tony6dda9262011-08-11 15:14:39 -0700310 if (rc && (rc != -EEXIST || !quiet))
Tony Luckca01d6d2010-12-28 14:25:21 -0800311 failed++;
312 }
Kees Cook2174f6d2011-11-18 13:49:00 -0800313 if (psi->close)
314 psi->close(psi);
Chen Gong06cf91b2011-05-16 11:00:27 -0700315out:
Kees Cookf6f82852011-11-17 12:58:07 -0800316 mutex_unlock(&psi->read_mutex);
Tony Luckca01d6d2010-12-28 14:25:21 -0800317
318 if (failed)
319 printk(KERN_WARNING "pstore: failed to load %d record(s) from '%s'\n",
320 failed, psi->name);
321}
322
Luck, Tony6dda9262011-08-11 15:14:39 -0700323static void pstore_dowork(struct work_struct *work)
324{
325 pstore_get_records(1);
326}
327
328static void pstore_timefunc(unsigned long dummy)
329{
330 if (pstore_new_entry) {
331 pstore_new_entry = 0;
332 schedule_work(&pstore_work);
333 }
334
Anton Vorontsova3f5f072012-05-26 06:20:28 -0700335 mod_timer(&pstore_timer, jiffies + msecs_to_jiffies(pstore_update_ms));
Luck, Tony6dda9262011-08-11 15:14:39 -0700336}
337
Matthew Garrettdee28e72011-07-21 16:57:55 -0400338module_param(backend, charp, 0444);
339MODULE_PARM_DESC(backend, "Pstore backend to use");