pstore: add lzo/lz4 compression support
[linux-stable.git] / fs / pstore / ram.c
blobd9668c2b43cbde7ba4235b5a2e99f820899ee161
1 /*
2 * RAM Oops/Panic logger
4 * Copyright (C) 2010 Marco Stornelli <marco.stornelli@gmail.com>
5 * Copyright (C) 2011 Kees Cook <keescook@chromium.org>
7 * This program is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU General Public License
9 * version 2 as published by the Free Software Foundation.
11 * This program is distributed in the hope that it will be useful, but
12 * WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 * General Public License for more details.
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., 51 Franklin St, Fifth Floor, Boston, MA
19 * 02110-1301 USA
23 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
25 #include <linux/kernel.h>
26 #include <linux/err.h>
27 #include <linux/module.h>
28 #include <linux/version.h>
29 #include <linux/pstore.h>
30 #include <linux/time.h>
31 #include <linux/io.h>
32 #include <linux/ioport.h>
33 #include <linux/platform_device.h>
34 #include <linux/slab.h>
35 #include <linux/compiler.h>
36 #include <linux/pstore_ram.h>
38 #define RAMOOPS_KERNMSG_HDR "===="
39 #define MIN_MEM_SIZE 4096UL
41 static ulong record_size = MIN_MEM_SIZE;
42 module_param(record_size, ulong, 0400);
43 MODULE_PARM_DESC(record_size,
44 "size of each dump done on oops/panic");
46 static ulong ramoops_console_size = MIN_MEM_SIZE;
47 module_param_named(console_size, ramoops_console_size, ulong, 0400);
48 MODULE_PARM_DESC(console_size, "size of kernel console log");
50 static ulong ramoops_ftrace_size = MIN_MEM_SIZE;
51 module_param_named(ftrace_size, ramoops_ftrace_size, ulong, 0400);
52 MODULE_PARM_DESC(ftrace_size, "size of ftrace log");
54 static ulong ramoops_pmsg_size = MIN_MEM_SIZE;
55 module_param_named(pmsg_size, ramoops_pmsg_size, ulong, 0400);
56 MODULE_PARM_DESC(pmsg_size, "size of user space message log");
58 static unsigned long long mem_address;
59 module_param(mem_address, ullong, 0400);
60 MODULE_PARM_DESC(mem_address,
61 "start of reserved RAM used to store oops/panic logs");
63 static ulong mem_size;
64 module_param(mem_size, ulong, 0400);
65 MODULE_PARM_DESC(mem_size,
66 "size of reserved RAM used to store oops/panic logs");
68 static unsigned int mem_type;
69 module_param(mem_type, uint, 0600);
70 MODULE_PARM_DESC(mem_type,
71 "set to 1 to try to use unbuffered memory (default 0)");
73 static int dump_oops = 1;
74 module_param(dump_oops, int, 0600);
75 MODULE_PARM_DESC(dump_oops,
76 "set to 1 to dump oopses, 0 to only dump panics (default 1)");
78 static int ramoops_ecc;
79 module_param_named(ecc, ramoops_ecc, int, 0600);
80 MODULE_PARM_DESC(ramoops_ecc,
81 "if non-zero, the option enables ECC support and specifies "
82 "ECC buffer size in bytes (1 is a special value, means 16 "
83 "bytes ECC)");
85 struct ramoops_context {
86 struct persistent_ram_zone **przs;
87 struct persistent_ram_zone *cprz;
88 struct persistent_ram_zone *fprz;
89 struct persistent_ram_zone *mprz;
90 phys_addr_t phys_addr;
91 unsigned long size;
92 unsigned int memtype;
93 size_t record_size;
94 size_t console_size;
95 size_t ftrace_size;
96 size_t pmsg_size;
97 int dump_oops;
98 struct persistent_ram_ecc_info ecc_info;
99 unsigned int max_dump_cnt;
100 unsigned int dump_write_cnt;
101 /* _read_cnt need clear on ramoops_pstore_open */
102 unsigned int dump_read_cnt;
103 unsigned int console_read_cnt;
104 unsigned int ftrace_read_cnt;
105 unsigned int pmsg_read_cnt;
106 struct pstore_info pstore;
109 static struct platform_device *dummy;
110 static struct ramoops_platform_data *dummy_data;
112 static int ramoops_pstore_open(struct pstore_info *psi)
114 struct ramoops_context *cxt = psi->data;
116 cxt->dump_read_cnt = 0;
117 cxt->console_read_cnt = 0;
118 cxt->ftrace_read_cnt = 0;
119 cxt->pmsg_read_cnt = 0;
120 return 0;
123 static struct persistent_ram_zone *
124 ramoops_get_next_prz(struct persistent_ram_zone *przs[], uint *c, uint max,
125 u64 *id,
126 enum pstore_type_id *typep, enum pstore_type_id type,
127 bool update)
129 struct persistent_ram_zone *prz;
130 int i = (*c)++;
132 if (i >= max)
133 return NULL;
135 prz = przs[i];
136 if (!prz)
137 return NULL;
139 /* Update old/shadowed buffer. */
140 if (update)
141 persistent_ram_save_old(prz);
143 if (!persistent_ram_old_size(prz))
144 return NULL;
146 *typep = type;
147 *id = i;
149 return prz;
152 static int ramoops_read_kmsg_hdr(char *buffer, struct timespec *time,
153 bool *compressed)
155 char data_type;
156 int header_length = 0;
158 if (sscanf(buffer, RAMOOPS_KERNMSG_HDR "%lu.%lu-%c\n%n", &time->tv_sec,
159 &time->tv_nsec, &data_type, &header_length) == 3) {
160 if (data_type == 'C')
161 *compressed = true;
162 else
163 *compressed = false;
164 } else if (sscanf(buffer, RAMOOPS_KERNMSG_HDR "%lu.%lu\n%n",
165 &time->tv_sec, &time->tv_nsec, &header_length) == 2) {
166 *compressed = false;
167 } else {
168 time->tv_sec = 0;
169 time->tv_nsec = 0;
170 *compressed = false;
172 return header_length;
175 static bool prz_ok(struct persistent_ram_zone *prz)
177 return !!prz && !!(persistent_ram_old_size(prz) +
178 persistent_ram_ecc_string(prz, NULL, 0));
181 static ssize_t ramoops_pstore_read(u64 *id, enum pstore_type_id *type,
182 int *count, struct timespec *time,
183 char **buf, bool *compressed,
184 ssize_t *ecc_notice_size,
185 struct pstore_info *psi)
187 ssize_t size;
188 struct ramoops_context *cxt = psi->data;
189 struct persistent_ram_zone *prz = NULL;
190 int header_length = 0;
192 /* Ramoops headers provide time stamps for PSTORE_TYPE_DMESG, but
193 * PSTORE_TYPE_CONSOLE and PSTORE_TYPE_FTRACE don't currently have
194 * valid time stamps, so it is initialized to zero.
196 time->tv_sec = 0;
197 time->tv_nsec = 0;
198 *compressed = false;
200 /* Find the next valid persistent_ram_zone for DMESG */
201 while (cxt->dump_read_cnt < cxt->max_dump_cnt && !prz) {
202 prz = ramoops_get_next_prz(cxt->przs, &cxt->dump_read_cnt,
203 cxt->max_dump_cnt, id, type,
204 PSTORE_TYPE_DMESG, 1);
205 if (!prz_ok(prz))
206 continue;
207 header_length = ramoops_read_kmsg_hdr(persistent_ram_old(prz),
208 time, compressed);
209 /* Clear and skip this DMESG record if it has no valid header */
210 if (!header_length) {
211 persistent_ram_free_old(prz);
212 persistent_ram_zap(prz);
213 prz = NULL;
217 if (!prz_ok(prz))
218 prz = ramoops_get_next_prz(&cxt->cprz, &cxt->console_read_cnt,
219 1, id, type, PSTORE_TYPE_CONSOLE, 0);
220 if (!prz_ok(prz))
221 prz = ramoops_get_next_prz(&cxt->fprz, &cxt->ftrace_read_cnt,
222 1, id, type, PSTORE_TYPE_FTRACE, 0);
223 if (!prz_ok(prz))
224 prz = ramoops_get_next_prz(&cxt->mprz, &cxt->pmsg_read_cnt,
225 1, id, type, PSTORE_TYPE_PMSG, 0);
226 if (!prz_ok(prz))
227 return 0;
229 size = persistent_ram_old_size(prz) - header_length;
231 /* ECC correction notice */
232 *ecc_notice_size = persistent_ram_ecc_string(prz, NULL, 0);
234 *buf = kmalloc(size + *ecc_notice_size + 1, GFP_KERNEL);
235 if (*buf == NULL)
236 return -ENOMEM;
238 memcpy(*buf, (char *)persistent_ram_old(prz) + header_length, size);
239 persistent_ram_ecc_string(prz, *buf + size, *ecc_notice_size + 1);
241 return size;
244 static size_t ramoops_write_kmsg_hdr(struct persistent_ram_zone *prz,
245 bool compressed)
247 char *hdr;
248 struct timespec timestamp;
249 size_t len;
251 /* Report zeroed timestamp if called before timekeeping has resumed. */
252 if (__getnstimeofday(&timestamp)) {
253 timestamp.tv_sec = 0;
254 timestamp.tv_nsec = 0;
256 hdr = kasprintf(GFP_ATOMIC, RAMOOPS_KERNMSG_HDR "%lu.%lu-%c\n",
257 (long)timestamp.tv_sec, (long)(timestamp.tv_nsec / 1000),
258 compressed ? 'C' : 'D');
259 WARN_ON_ONCE(!hdr);
260 len = hdr ? strlen(hdr) : 0;
261 persistent_ram_write(prz, hdr, len);
262 kfree(hdr);
264 return len;
267 static int notrace ramoops_pstore_write_buf(enum pstore_type_id type,
268 enum kmsg_dump_reason reason,
269 u64 *id, unsigned int part,
270 const char *buf,
271 bool compressed, size_t size,
272 struct pstore_info *psi)
274 struct ramoops_context *cxt = psi->data;
275 struct persistent_ram_zone *prz;
276 size_t hlen;
278 if (type == PSTORE_TYPE_CONSOLE) {
279 if (!cxt->cprz)
280 return -ENOMEM;
281 persistent_ram_write(cxt->cprz, buf, size);
282 return 0;
283 } else if (type == PSTORE_TYPE_FTRACE) {
284 if (!cxt->fprz)
285 return -ENOMEM;
286 persistent_ram_write(cxt->fprz, buf, size);
287 return 0;
288 } else if (type == PSTORE_TYPE_PMSG) {
289 if (!cxt->mprz)
290 return -ENOMEM;
291 persistent_ram_write(cxt->mprz, buf, size);
292 return 0;
295 if (type != PSTORE_TYPE_DMESG)
296 return -EINVAL;
298 /* Out of the various dmesg dump types, ramoops is currently designed
299 * to only store crash logs, rather than storing general kernel logs.
301 if (reason != KMSG_DUMP_OOPS &&
302 reason != KMSG_DUMP_PANIC)
303 return -EINVAL;
305 /* Skip Oopes when configured to do so. */
306 if (reason == KMSG_DUMP_OOPS && !cxt->dump_oops)
307 return -EINVAL;
309 /* Explicitly only take the first part of any new crash.
310 * If our buffer is larger than kmsg_bytes, this can never happen,
311 * and if our buffer is smaller than kmsg_bytes, we don't want the
312 * report split across multiple records.
314 if (part != 1)
315 return -ENOSPC;
317 if (!cxt->przs)
318 return -ENOSPC;
320 prz = cxt->przs[cxt->dump_write_cnt];
322 hlen = ramoops_write_kmsg_hdr(prz, compressed);
323 if (size + hlen > prz->buffer_size)
324 size = prz->buffer_size - hlen;
325 persistent_ram_write(prz, buf, size);
327 cxt->dump_write_cnt = (cxt->dump_write_cnt + 1) % cxt->max_dump_cnt;
329 return 0;
332 static int ramoops_pstore_erase(enum pstore_type_id type, u64 id, int count,
333 struct timespec time, struct pstore_info *psi)
335 struct ramoops_context *cxt = psi->data;
336 struct persistent_ram_zone *prz;
338 switch (type) {
339 case PSTORE_TYPE_DMESG:
340 if (id >= cxt->max_dump_cnt)
341 return -EINVAL;
342 prz = cxt->przs[id];
343 break;
344 case PSTORE_TYPE_CONSOLE:
345 prz = cxt->cprz;
346 break;
347 case PSTORE_TYPE_FTRACE:
348 prz = cxt->fprz;
349 break;
350 case PSTORE_TYPE_PMSG:
351 prz = cxt->mprz;
352 break;
353 default:
354 return -EINVAL;
357 persistent_ram_free_old(prz);
358 persistent_ram_zap(prz);
360 return 0;
363 static struct ramoops_context oops_cxt = {
364 .pstore = {
365 .owner = THIS_MODULE,
366 .name = "ramoops",
367 .open = ramoops_pstore_open,
368 .read = ramoops_pstore_read,
369 .write_buf = ramoops_pstore_write_buf,
370 .erase = ramoops_pstore_erase,
374 static void ramoops_free_przs(struct ramoops_context *cxt)
376 int i;
378 cxt->max_dump_cnt = 0;
379 if (!cxt->przs)
380 return;
382 for (i = 0; !IS_ERR_OR_NULL(cxt->przs[i]); i++)
383 persistent_ram_free(cxt->przs[i]);
384 kfree(cxt->przs);
387 static int ramoops_init_przs(struct device *dev, struct ramoops_context *cxt,
388 phys_addr_t *paddr, size_t dump_mem_sz)
390 int err = -ENOMEM;
391 int i;
393 if (!cxt->record_size)
394 return 0;
396 if (*paddr + dump_mem_sz - cxt->phys_addr > cxt->size) {
397 dev_err(dev, "no room for dumps\n");
398 return -ENOMEM;
401 cxt->max_dump_cnt = dump_mem_sz / cxt->record_size;
402 if (!cxt->max_dump_cnt)
403 return -ENOMEM;
405 cxt->przs = kzalloc(sizeof(*cxt->przs) * cxt->max_dump_cnt,
406 GFP_KERNEL);
407 if (!cxt->przs) {
408 dev_err(dev, "failed to initialize a prz array for dumps\n");
409 goto fail_prz;
412 for (i = 0; i < cxt->max_dump_cnt; i++) {
413 cxt->przs[i] = persistent_ram_new(*paddr, cxt->record_size, 0,
414 &cxt->ecc_info,
415 cxt->memtype);
416 if (IS_ERR(cxt->przs[i])) {
417 err = PTR_ERR(cxt->przs[i]);
418 dev_err(dev, "failed to request mem region (0x%zx@0x%llx): %d\n",
419 cxt->record_size, (unsigned long long)*paddr, err);
420 goto fail_prz;
422 *paddr += cxt->record_size;
425 return 0;
426 fail_prz:
427 ramoops_free_przs(cxt);
428 return err;
431 static int ramoops_init_prz(struct device *dev, struct ramoops_context *cxt,
432 struct persistent_ram_zone **prz,
433 phys_addr_t *paddr, size_t sz, u32 sig)
435 if (!sz)
436 return 0;
438 if (*paddr + sz - cxt->phys_addr > cxt->size) {
439 dev_err(dev, "no room for mem region (0x%zx@0x%llx) in (0x%lx@0x%llx)\n",
440 sz, (unsigned long long)*paddr,
441 cxt->size, (unsigned long long)cxt->phys_addr);
442 return -ENOMEM;
445 *prz = persistent_ram_new(*paddr, sz, sig, &cxt->ecc_info, cxt->memtype);
446 if (IS_ERR(*prz)) {
447 int err = PTR_ERR(*prz);
449 dev_err(dev, "failed to request mem region (0x%zx@0x%llx): %d\n",
450 sz, (unsigned long long)*paddr, err);
451 return err;
454 persistent_ram_zap(*prz);
456 *paddr += sz;
458 return 0;
461 static int ramoops_probe(struct platform_device *pdev)
463 struct device *dev = &pdev->dev;
464 struct ramoops_platform_data *pdata = pdev->dev.platform_data;
465 struct ramoops_context *cxt = &oops_cxt;
466 size_t dump_mem_sz;
467 phys_addr_t paddr;
468 int err = -EINVAL;
470 /* Only a single ramoops area allowed at a time, so fail extra
471 * probes.
473 if (cxt->max_dump_cnt)
474 goto fail_out;
476 if (!pdata->mem_size || (!pdata->record_size && !pdata->console_size &&
477 !pdata->ftrace_size && !pdata->pmsg_size)) {
478 pr_err("The memory size and the record/console size must be "
479 "non-zero\n");
480 goto fail_out;
483 if (pdata->record_size && !is_power_of_2(pdata->record_size))
484 pdata->record_size = rounddown_pow_of_two(pdata->record_size);
485 if (pdata->console_size && !is_power_of_2(pdata->console_size))
486 pdata->console_size = rounddown_pow_of_two(pdata->console_size);
487 if (pdata->ftrace_size && !is_power_of_2(pdata->ftrace_size))
488 pdata->ftrace_size = rounddown_pow_of_two(pdata->ftrace_size);
489 if (pdata->pmsg_size && !is_power_of_2(pdata->pmsg_size))
490 pdata->pmsg_size = rounddown_pow_of_two(pdata->pmsg_size);
492 cxt->size = pdata->mem_size;
493 cxt->phys_addr = pdata->mem_address;
494 cxt->memtype = pdata->mem_type;
495 cxt->record_size = pdata->record_size;
496 cxt->console_size = pdata->console_size;
497 cxt->ftrace_size = pdata->ftrace_size;
498 cxt->pmsg_size = pdata->pmsg_size;
499 cxt->dump_oops = pdata->dump_oops;
500 cxt->ecc_info = pdata->ecc_info;
502 paddr = cxt->phys_addr;
504 dump_mem_sz = cxt->size - cxt->console_size - cxt->ftrace_size
505 - cxt->pmsg_size;
506 err = ramoops_init_przs(dev, cxt, &paddr, dump_mem_sz);
507 if (err)
508 goto fail_out;
510 err = ramoops_init_prz(dev, cxt, &cxt->cprz, &paddr,
511 cxt->console_size, 0);
512 if (err)
513 goto fail_init_cprz;
515 err = ramoops_init_prz(dev, cxt, &cxt->fprz, &paddr, cxt->ftrace_size,
516 LINUX_VERSION_CODE);
517 if (err)
518 goto fail_init_fprz;
520 err = ramoops_init_prz(dev, cxt, &cxt->mprz, &paddr, cxt->pmsg_size, 0);
521 if (err)
522 goto fail_init_mprz;
524 cxt->pstore.data = cxt;
526 * Console can handle any buffer size, so prefer LOG_LINE_MAX. If we
527 * have to handle dumps, we must have at least record_size buffer. And
528 * for ftrace, bufsize is irrelevant (if bufsize is 0, buf will be
529 * ZERO_SIZE_PTR).
531 if (cxt->console_size)
532 cxt->pstore.bufsize = 1024; /* LOG_LINE_MAX */
533 cxt->pstore.bufsize = max(cxt->record_size, cxt->pstore.bufsize);
534 cxt->pstore.buf = kmalloc(cxt->pstore.bufsize, GFP_KERNEL);
535 spin_lock_init(&cxt->pstore.buf_lock);
536 if (!cxt->pstore.buf) {
537 pr_err("cannot allocate pstore buffer\n");
538 err = -ENOMEM;
539 goto fail_clear;
542 err = pstore_register(&cxt->pstore);
543 if (err) {
544 pr_err("registering with pstore failed\n");
545 goto fail_buf;
549 * Update the module parameter variables as well so they are visible
550 * through /sys/module/ramoops/parameters/
552 mem_size = pdata->mem_size;
553 mem_address = pdata->mem_address;
554 record_size = pdata->record_size;
555 dump_oops = pdata->dump_oops;
556 ramoops_console_size = pdata->console_size;
557 ramoops_pmsg_size = pdata->pmsg_size;
558 ramoops_ftrace_size = pdata->ftrace_size;
560 pr_info("attached 0x%lx@0x%llx, ecc: %d/%d\n",
561 cxt->size, (unsigned long long)cxt->phys_addr,
562 cxt->ecc_info.ecc_size, cxt->ecc_info.block_size);
564 return 0;
566 fail_buf:
567 kfree(cxt->pstore.buf);
568 fail_clear:
569 cxt->pstore.bufsize = 0;
570 kfree(cxt->mprz);
571 fail_init_mprz:
572 kfree(cxt->fprz);
573 fail_init_fprz:
574 kfree(cxt->cprz);
575 fail_init_cprz:
576 ramoops_free_przs(cxt);
577 fail_out:
578 return err;
581 static int ramoops_remove(struct platform_device *pdev)
583 struct ramoops_context *cxt = &oops_cxt;
585 pstore_unregister(&cxt->pstore);
586 cxt->max_dump_cnt = 0;
588 kfree(cxt->pstore.buf);
589 cxt->pstore.bufsize = 0;
591 persistent_ram_free(cxt->mprz);
592 persistent_ram_free(cxt->fprz);
593 persistent_ram_free(cxt->cprz);
594 ramoops_free_przs(cxt);
596 return 0;
599 static struct platform_driver ramoops_driver = {
600 .probe = ramoops_probe,
601 .remove = ramoops_remove,
602 .driver = {
603 .name = "ramoops",
607 static void ramoops_register_dummy(void)
609 if (!mem_size)
610 return;
612 pr_info("using module parameters\n");
614 dummy_data = kzalloc(sizeof(*dummy_data), GFP_KERNEL);
615 if (!dummy_data) {
616 pr_info("could not allocate pdata\n");
617 return;
620 dummy_data->mem_size = mem_size;
621 dummy_data->mem_address = mem_address;
622 dummy_data->mem_type = mem_type;
623 dummy_data->record_size = record_size;
624 dummy_data->console_size = ramoops_console_size;
625 dummy_data->ftrace_size = ramoops_ftrace_size;
626 dummy_data->pmsg_size = ramoops_pmsg_size;
627 dummy_data->dump_oops = dump_oops;
629 * For backwards compatibility ramoops.ecc=1 means 16 bytes ECC
630 * (using 1 byte for ECC isn't much of use anyway).
632 dummy_data->ecc_info.ecc_size = ramoops_ecc == 1 ? 16 : ramoops_ecc;
634 dummy = platform_device_register_data(NULL, "ramoops", -1,
635 dummy_data, sizeof(struct ramoops_platform_data));
636 if (IS_ERR(dummy)) {
637 pr_info("could not create platform device: %ld\n",
638 PTR_ERR(dummy));
642 static int __init ramoops_init(void)
644 ramoops_register_dummy();
645 return platform_driver_register(&ramoops_driver);
647 postcore_initcall(ramoops_init);
649 static void __exit ramoops_exit(void)
651 platform_driver_unregister(&ramoops_driver);
652 platform_device_unregister(dummy);
653 kfree(dummy_data);
655 module_exit(ramoops_exit);
657 MODULE_LICENSE("GPL");
658 MODULE_AUTHOR("Marco Stornelli <marco.stornelli@gmail.com>");
659 MODULE_DESCRIPTION("RAM Oops/Panic logger/driver");