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Commit | Line | Data |
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ca01d6dd TL |
1 | /* |
2 | * Persistent Storage - platform driver interface parts. | |
3 | * | |
f29e5956 | 4 | * Copyright (C) 2007-2008 Google, Inc. |
ca01d6dd TL |
5 | * 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> | |
f29e5956 | 26 | #include <linux/console.h> |
ca01d6dd TL |
27 | #include <linux/module.h> |
28 | #include <linux/pstore.h> | |
29 | #include <linux/string.h> | |
6dda9266 | 30 | #include <linux/timer.h> |
ca01d6dd TL |
31 | #include <linux/slab.h> |
32 | #include <linux/uaccess.h> | |
abd4d558 | 33 | #include <linux/hardirq.h> |
a3f5f075 | 34 | #include <linux/jiffies.h> |
6dda9266 | 35 | #include <linux/workqueue.h> |
ca01d6dd TL |
36 | |
37 | #include "internal.h" | |
38 | ||
6dda9266 TL |
39 | /* |
40 | * 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 | */ | |
521f7288 | 44 | static int pstore_update_ms = -1; |
a3f5f075 AV |
45 | module_param_named(update_ms, pstore_update_ms, int, 0600); |
46 | MODULE_PARM_DESC(update_ms, "milliseconds before pstore updates its content " | |
521f7288 AV |
47 | "(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)"); | |
6dda9266 TL |
50 | |
51 | static int pstore_new_entry; | |
52 | ||
53 | static void pstore_timefunc(unsigned long); | |
54 | static DEFINE_TIMER(pstore_timer, pstore_timefunc, 0, 0); | |
55 | ||
56 | static void pstore_dowork(struct work_struct *); | |
57 | static DECLARE_WORK(pstore_work, pstore_dowork); | |
58 | ||
ca01d6dd TL |
59 | /* |
60 | * pstore_lock just protects "psinfo" during | |
61 | * calls to pstore_register() | |
62 | */ | |
63 | static DEFINE_SPINLOCK(pstore_lock); | |
060287b8 | 64 | struct pstore_info *psinfo; |
ca01d6dd | 65 | |
dee28e72 MG |
66 | static char *backend; |
67 | ||
366f7e7a | 68 | /* How much of the console log to snapshot */ |
ca01d6dd TL |
69 | static unsigned long kmsg_bytes = 10240; |
70 | ||
366f7e7a | 71 | void pstore_set_kmsg_bytes(int bytes) |
ca01d6dd | 72 | { |
366f7e7a | 73 | kmsg_bytes = bytes; |
ca01d6dd TL |
74 | } |
75 | ||
ca01d6dd TL |
76 | /* Tag each group of saved records with a sequence number */ |
77 | static int oopscount; | |
78 | ||
381b872c SA |
79 | static 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 | } | |
9f6af27f | 98 | |
ca01d6dd TL |
99 | /* |
100 | * callback from kmsg_dump. (s2,l2) has the most recently | |
101 | * written bytes, older bytes are in (s1,l1). Save as much | |
102 | * as we can from the end of the buffer. | |
103 | */ | |
104 | static void pstore_dump(struct kmsg_dumper *dumper, | |
e2ae715d | 105 | enum kmsg_dump_reason reason) |
ca01d6dd | 106 | { |
e2ae715d | 107 | unsigned long total = 0; |
381b872c | 108 | const char *why; |
ca01d6dd | 109 | u64 id; |
b94fdd07 | 110 | unsigned int part = 1; |
abd4d558 DZ |
111 | unsigned long flags = 0; |
112 | int is_locked = 0; | |
e2ae715d | 113 | int ret; |
ca01d6dd | 114 | |
381b872c | 115 | why = get_reason_str(reason); |
9f6af27f | 116 | |
abd4d558 DZ |
117 | if (in_nmi()) { |
118 | is_locked = spin_trylock(&psinfo->buf_lock); | |
119 | if (!is_locked) | |
120 | pr_err("pstore dump routine blocked in NMI, may corrupt error record\n"); | |
121 | } else | |
122 | spin_lock_irqsave(&psinfo->buf_lock, flags); | |
ca01d6dd TL |
123 | oopscount++; |
124 | while (total < kmsg_bytes) { | |
e2ae715d KS |
125 | char *dst; |
126 | unsigned long size; | |
127 | int hsize; | |
128 | size_t len; | |
129 | ||
ca01d6dd | 130 | dst = psinfo->buf; |
56280682 | 131 | hsize = sprintf(dst, "%s#%d Part%d\n", why, oopscount, part); |
ca01d6dd TL |
132 | size = psinfo->bufsize - hsize; |
133 | dst += hsize; | |
134 | ||
e2ae715d | 135 | if (!kmsg_dump_get_buffer(dumper, true, dst, size, &len)) |
ca01d6dd TL |
136 | break; |
137 | ||
3d6d8d20 | 138 | ret = psinfo->write(PSTORE_TYPE_DMESG, reason, &id, part, |
e2ae715d | 139 | hsize + len, psinfo); |
b238b8fa | 140 | if (ret == 0 && reason == KMSG_DUMP_OOPS && pstore_is_mounted()) |
6dda9266 | 141 | pstore_new_entry = 1; |
e2ae715d KS |
142 | |
143 | total += hsize + len; | |
56280682 | 144 | part++; |
ca01d6dd | 145 | } |
abd4d558 DZ |
146 | if (in_nmi()) { |
147 | if (is_locked) | |
148 | spin_unlock(&psinfo->buf_lock); | |
149 | } else | |
150 | spin_unlock_irqrestore(&psinfo->buf_lock, flags); | |
ca01d6dd TL |
151 | } |
152 | ||
153 | static struct kmsg_dumper pstore_dumper = { | |
154 | .dump = pstore_dump, | |
155 | }; | |
156 | ||
f29e5956 AV |
157 | #ifdef CONFIG_PSTORE_CONSOLE |
158 | static void pstore_console_write(struct console *con, const char *s, unsigned c) | |
159 | { | |
160 | const char *e = s + c; | |
161 | ||
162 | while (s < e) { | |
163 | unsigned long flags; | |
70a6f46d | 164 | u64 id; |
f29e5956 AV |
165 | |
166 | if (c > psinfo->bufsize) | |
167 | c = psinfo->bufsize; | |
80c9d03c CL |
168 | |
169 | if (oops_in_progress) { | |
170 | if (!spin_trylock_irqsave(&psinfo->buf_lock, flags)) | |
171 | break; | |
172 | } else { | |
173 | spin_lock_irqsave(&psinfo->buf_lock, flags); | |
174 | } | |
f29e5956 | 175 | memcpy(psinfo->buf, s, c); |
70a6f46d | 176 | psinfo->write(PSTORE_TYPE_CONSOLE, 0, &id, 0, c, psinfo); |
f29e5956 AV |
177 | spin_unlock_irqrestore(&psinfo->buf_lock, flags); |
178 | s += c; | |
179 | c = e - s; | |
180 | } | |
181 | } | |
182 | ||
183 | static struct console pstore_console = { | |
184 | .name = "pstore", | |
185 | .write = pstore_console_write, | |
186 | .flags = CON_PRINTBUFFER | CON_ENABLED | CON_ANYTIME, | |
187 | .index = -1, | |
188 | }; | |
189 | ||
190 | static void pstore_register_console(void) | |
191 | { | |
192 | register_console(&pstore_console); | |
193 | } | |
194 | #else | |
195 | static void pstore_register_console(void) {} | |
196 | #endif | |
197 | ||
897dba02 AV |
198 | static int pstore_write_compat(enum pstore_type_id type, |
199 | enum kmsg_dump_reason reason, | |
200 | u64 *id, unsigned int part, | |
201 | size_t size, struct pstore_info *psi) | |
202 | { | |
203 | return psi->write_buf(type, reason, id, part, psinfo->buf, size, psi); | |
204 | } | |
205 | ||
ca01d6dd TL |
206 | /* |
207 | * platform specific persistent storage driver registers with | |
208 | * us here. If pstore is already mounted, call the platform | |
209 | * read function right away to populate the file system. If not | |
210 | * then the pstore mount code will call us later to fill out | |
211 | * the file system. | |
212 | * | |
213 | * Register with kmsg_dump to save last part of console log on panic. | |
214 | */ | |
215 | int pstore_register(struct pstore_info *psi) | |
216 | { | |
217 | struct module *owner = psi->owner; | |
218 | ||
219 | spin_lock(&pstore_lock); | |
220 | if (psinfo) { | |
221 | spin_unlock(&pstore_lock); | |
222 | return -EBUSY; | |
223 | } | |
dee28e72 MG |
224 | |
225 | if (backend && strcmp(backend, psi->name)) { | |
226 | spin_unlock(&pstore_lock); | |
227 | return -EINVAL; | |
228 | } | |
229 | ||
897dba02 AV |
230 | if (!psi->write) |
231 | psi->write = pstore_write_compat; | |
ca01d6dd | 232 | psinfo = psi; |
f6f82851 | 233 | mutex_init(&psinfo->read_mutex); |
ca01d6dd TL |
234 | spin_unlock(&pstore_lock); |
235 | ||
236 | if (owner && !try_module_get(owner)) { | |
237 | psinfo = NULL; | |
238 | return -EINVAL; | |
239 | } | |
240 | ||
241 | if (pstore_is_mounted()) | |
6dda9266 | 242 | pstore_get_records(0); |
ca01d6dd TL |
243 | |
244 | kmsg_dump_register(&pstore_dumper); | |
f29e5956 | 245 | pstore_register_console(); |
65f8c95e | 246 | pstore_register_ftrace(); |
ca01d6dd | 247 | |
a3f5f075 AV |
248 | if (pstore_update_ms >= 0) { |
249 | pstore_timer.expires = jiffies + | |
250 | msecs_to_jiffies(pstore_update_ms); | |
251 | add_timer(&pstore_timer); | |
252 | } | |
6dda9266 | 253 | |
ca01d6dd TL |
254 | return 0; |
255 | } | |
256 | EXPORT_SYMBOL_GPL(pstore_register); | |
257 | ||
258 | /* | |
6dda9266 TL |
259 | * Read all the records from the persistent store. Create |
260 | * files in our filesystem. Don't warn about -EEXIST errors | |
261 | * when we are re-scanning the backing store looking to add new | |
262 | * error records. | |
ca01d6dd | 263 | */ |
6dda9266 | 264 | void pstore_get_records(int quiet) |
ca01d6dd TL |
265 | { |
266 | struct pstore_info *psi = psinfo; | |
f6f82851 | 267 | char *buf = NULL; |
8d38d74b | 268 | ssize_t size; |
ca01d6dd TL |
269 | u64 id; |
270 | enum pstore_type_id type; | |
271 | struct timespec time; | |
06cf91b4 | 272 | int failed = 0, rc; |
ca01d6dd TL |
273 | |
274 | if (!psi) | |
275 | return; | |
276 | ||
f6f82851 | 277 | mutex_lock(&psi->read_mutex); |
2174f6df | 278 | if (psi->open && psi->open(psi)) |
06cf91b4 CG |
279 | goto out; |
280 | ||
f6f82851 KC |
281 | while ((size = psi->read(&id, &type, &time, &buf, psi)) > 0) { |
282 | rc = pstore_mkfile(type, psi->name, id, buf, (size_t)size, | |
6dda9266 | 283 | time, psi); |
f6f82851 KC |
284 | kfree(buf); |
285 | buf = NULL; | |
6dda9266 | 286 | if (rc && (rc != -EEXIST || !quiet)) |
ca01d6dd TL |
287 | failed++; |
288 | } | |
2174f6df KC |
289 | if (psi->close) |
290 | psi->close(psi); | |
06cf91b4 | 291 | out: |
f6f82851 | 292 | mutex_unlock(&psi->read_mutex); |
ca01d6dd TL |
293 | |
294 | if (failed) | |
295 | printk(KERN_WARNING "pstore: failed to load %d record(s) from '%s'\n", | |
296 | failed, psi->name); | |
297 | } | |
298 | ||
6dda9266 TL |
299 | static void pstore_dowork(struct work_struct *work) |
300 | { | |
301 | pstore_get_records(1); | |
302 | } | |
303 | ||
304 | static void pstore_timefunc(unsigned long dummy) | |
305 | { | |
306 | if (pstore_new_entry) { | |
307 | pstore_new_entry = 0; | |
308 | schedule_work(&pstore_work); | |
309 | } | |
310 | ||
a3f5f075 | 311 | mod_timer(&pstore_timer, jiffies + msecs_to_jiffies(pstore_update_ms)); |
6dda9266 TL |
312 | } |
313 | ||
dee28e72 MG |
314 | module_param(backend, charp, 0444); |
315 | MODULE_PARM_DESC(backend, "Pstore backend to use"); |