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1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * RAM Oops/Panic logger
4 *
5 * Copyright (C) 2010 Marco Stornelli <marco.stornelli@gmail.com>
6 * Copyright (C) 2011 Kees Cook <keescook@chromium.org>
7 */
8
9#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
10
11#include <linux/kernel.h>
12#include <linux/err.h>
13#include <linux/module.h>
14#include <linux/version.h>
15#include <linux/pstore.h>
16#include <linux/io.h>
17#include <linux/ioport.h>
18#include <linux/platform_device.h>
19#include <linux/slab.h>
20#include <linux/compiler.h>
21#include <linux/of.h>
22#include <linux/of_address.h>
23#include <linux/mm.h>
24
25#include "internal.h"
26#include "ram_internal.h"
27
28#define RAMOOPS_KERNMSG_HDR "===="
29#define MIN_MEM_SIZE 4096UL
30
31static ulong record_size = MIN_MEM_SIZE;
32module_param(record_size, ulong, 0400);
33MODULE_PARM_DESC(record_size,
34 "size of each dump done on oops/panic");
35
36static ulong ramoops_console_size = MIN_MEM_SIZE;
37module_param_named(console_size, ramoops_console_size, ulong, 0400);
38MODULE_PARM_DESC(console_size, "size of kernel console log");
39
40static ulong ramoops_ftrace_size = MIN_MEM_SIZE;
41module_param_named(ftrace_size, ramoops_ftrace_size, ulong, 0400);
42MODULE_PARM_DESC(ftrace_size, "size of ftrace log");
43
44static ulong ramoops_pmsg_size = MIN_MEM_SIZE;
45module_param_named(pmsg_size, ramoops_pmsg_size, ulong, 0400);
46MODULE_PARM_DESC(pmsg_size, "size of user space message log");
47
48static unsigned long long mem_address;
49module_param_hw(mem_address, ullong, other, 0400);
50MODULE_PARM_DESC(mem_address,
51 "start of reserved RAM used to store oops/panic logs");
52
53static ulong mem_size;
54module_param(mem_size, ulong, 0400);
55MODULE_PARM_DESC(mem_size,
56 "size of reserved RAM used to store oops/panic logs");
57
58static unsigned int mem_type;
59module_param(mem_type, uint, 0400);
60MODULE_PARM_DESC(mem_type,
61 "memory type: 0=write-combined (default), 1=unbuffered, 2=cached");
62
63static int ramoops_max_reason = -1;
64module_param_named(max_reason, ramoops_max_reason, int, 0400);
65MODULE_PARM_DESC(max_reason,
66 "maximum reason for kmsg dump (default 2: Oops and Panic) ");
67
68static int ramoops_ecc;
69module_param_named(ecc, ramoops_ecc, int, 0400);
70MODULE_PARM_DESC(ramoops_ecc,
71 "if non-zero, the option enables ECC support and specifies "
72 "ECC buffer size in bytes (1 is a special value, means 16 "
73 "bytes ECC)");
74
75static int ramoops_dump_oops = -1;
76module_param_named(dump_oops, ramoops_dump_oops, int, 0400);
77MODULE_PARM_DESC(dump_oops,
78 "(deprecated: use max_reason instead) set to 1 to dump oopses & panics, 0 to only dump panics");
79
80struct ramoops_context {
81 struct persistent_ram_zone **dprzs; /* Oops dump zones */
82 struct persistent_ram_zone *cprz; /* Console zone */
83 struct persistent_ram_zone **fprzs; /* Ftrace zones */
84 struct persistent_ram_zone *mprz; /* PMSG zone */
85 phys_addr_t phys_addr;
86 unsigned long size;
87 unsigned int memtype;
88 size_t record_size;
89 size_t console_size;
90 size_t ftrace_size;
91 size_t pmsg_size;
92 u32 flags;
93 struct persistent_ram_ecc_info ecc_info;
94 unsigned int max_dump_cnt;
95 unsigned int dump_write_cnt;
96 /* _read_cnt need clear on ramoops_pstore_open */
97 unsigned int dump_read_cnt;
98 unsigned int console_read_cnt;
99 unsigned int max_ftrace_cnt;
100 unsigned int ftrace_read_cnt;
101 unsigned int pmsg_read_cnt;
102 struct pstore_info pstore;
103};
104
105static struct platform_device *dummy;
106
107static int ramoops_pstore_open(struct pstore_info *psi)
108{
109 struct ramoops_context *cxt = psi->data;
110
111 cxt->dump_read_cnt = 0;
112 cxt->console_read_cnt = 0;
113 cxt->ftrace_read_cnt = 0;
114 cxt->pmsg_read_cnt = 0;
115 return 0;
116}
117
118static struct persistent_ram_zone *
119ramoops_get_next_prz(struct persistent_ram_zone *przs[], int id,
120 struct pstore_record *record)
121{
122 struct persistent_ram_zone *prz;
123
124 /* Give up if we never existed or have hit the end. */
125 if (!przs)
126 return NULL;
127
128 prz = przs[id];
129 if (!prz)
130 return NULL;
131
132 /* Update old/shadowed buffer. */
133 if (prz->type == PSTORE_TYPE_DMESG)
134 persistent_ram_save_old(prz);
135
136 if (!persistent_ram_old_size(prz))
137 return NULL;
138
139 record->type = prz->type;
140 record->id = id;
141
142 return prz;
143}
144
145static int ramoops_read_kmsg_hdr(char *buffer, struct timespec64 *time,
146 bool *compressed)
147{
148 char data_type;
149 int header_length = 0;
150
151 if (sscanf(buffer, RAMOOPS_KERNMSG_HDR "%lld.%lu-%c\n%n",
152 (time64_t *)&time->tv_sec, &time->tv_nsec, &data_type,
153 &header_length) == 3) {
154 time->tv_nsec *= 1000;
155 if (data_type == 'C')
156 *compressed = true;
157 else
158 *compressed = false;
159 } else if (sscanf(buffer, RAMOOPS_KERNMSG_HDR "%lld.%lu\n%n",
160 (time64_t *)&time->tv_sec, &time->tv_nsec,
161 &header_length) == 2) {
162 time->tv_nsec *= 1000;
163 *compressed = false;
164 } else {
165 time->tv_sec = 0;
166 time->tv_nsec = 0;
167 *compressed = false;
168 }
169 return header_length;
170}
171
172static bool prz_ok(struct persistent_ram_zone *prz)
173{
174 return !!prz && !!(persistent_ram_old_size(prz) +
175 persistent_ram_ecc_string(prz, NULL, 0));
176}
177
178static ssize_t ramoops_pstore_read(struct pstore_record *record)
179{
180 ssize_t size = 0;
181 struct ramoops_context *cxt = record->psi->data;
182 struct persistent_ram_zone *prz = NULL;
183 int header_length = 0;
184 bool free_prz = false;
185
186 /*
187 * Ramoops headers provide time stamps for PSTORE_TYPE_DMESG, but
188 * PSTORE_TYPE_CONSOLE and PSTORE_TYPE_FTRACE don't currently have
189 * valid time stamps, so it is initialized to zero.
190 */
191 record->time.tv_sec = 0;
192 record->time.tv_nsec = 0;
193 record->compressed = false;
194
195 /* Find the next valid persistent_ram_zone for DMESG */
196 while (cxt->dump_read_cnt < cxt->max_dump_cnt && !prz) {
197 prz = ramoops_get_next_prz(cxt->dprzs, cxt->dump_read_cnt++,
198 record);
199 if (!prz_ok(prz))
200 continue;
201 header_length = ramoops_read_kmsg_hdr(persistent_ram_old(prz),
202 &record->time,
203 &record->compressed);
204 /* Clear and skip this DMESG record if it has no valid header */
205 if (!header_length) {
206 persistent_ram_free_old(prz);
207 persistent_ram_zap(prz);
208 prz = NULL;
209 }
210 }
211
212 if (!prz_ok(prz) && !cxt->console_read_cnt++)
213 prz = ramoops_get_next_prz(&cxt->cprz, 0 /* single */, record);
214
215 if (!prz_ok(prz) && !cxt->pmsg_read_cnt++)
216 prz = ramoops_get_next_prz(&cxt->mprz, 0 /* single */, record);
217
218 /* ftrace is last since it may want to dynamically allocate memory. */
219 if (!prz_ok(prz)) {
220 if (!(cxt->flags & RAMOOPS_FLAG_FTRACE_PER_CPU) &&
221 !cxt->ftrace_read_cnt++) {
222 prz = ramoops_get_next_prz(cxt->fprzs, 0 /* single */,
223 record);
224 } else {
225 /*
226 * Build a new dummy record which combines all the
227 * per-cpu records including metadata and ecc info.
228 */
229 struct persistent_ram_zone *tmp_prz, *prz_next;
230
231 tmp_prz = kzalloc(sizeof(struct persistent_ram_zone),
232 GFP_KERNEL);
233 if (!tmp_prz)
234 return -ENOMEM;
235 prz = tmp_prz;
236 free_prz = true;
237
238 while (cxt->ftrace_read_cnt < cxt->max_ftrace_cnt) {
239 prz_next = ramoops_get_next_prz(cxt->fprzs,
240 cxt->ftrace_read_cnt++, record);
241
242 if (!prz_ok(prz_next))
243 continue;
244
245 tmp_prz->ecc_info = prz_next->ecc_info;
246 tmp_prz->corrected_bytes +=
247 prz_next->corrected_bytes;
248 tmp_prz->bad_blocks += prz_next->bad_blocks;
249
250 size = pstore_ftrace_combine_log(
251 &tmp_prz->old_log,
252 &tmp_prz->old_log_size,
253 prz_next->old_log,
254 prz_next->old_log_size);
255 if (size)
256 goto out;
257 }
258 record->id = 0;
259 }
260 }
261
262 if (!prz_ok(prz)) {
263 size = 0;
264 goto out;
265 }
266
267 size = persistent_ram_old_size(prz) - header_length;
268
269 /* ECC correction notice */
270 record->ecc_notice_size = persistent_ram_ecc_string(prz, NULL, 0);
271
272 record->buf = kvzalloc(size + record->ecc_notice_size + 1, GFP_KERNEL);
273 if (record->buf == NULL) {
274 size = -ENOMEM;
275 goto out;
276 }
277
278 memcpy(record->buf, (char *)persistent_ram_old(prz) + header_length,
279 size);
280
281 persistent_ram_ecc_string(prz, record->buf + size,
282 record->ecc_notice_size + 1);
283
284out:
285 if (free_prz) {
286 kvfree(prz->old_log);
287 kfree(prz);
288 }
289
290 return size;
291}
292
293static size_t ramoops_write_kmsg_hdr(struct persistent_ram_zone *prz,
294 struct pstore_record *record)
295{
296 char hdr[36]; /* "===="(4), %lld(20), "."(1), %06lu(6), "-%c\n"(3) */
297 size_t len;
298
299 len = scnprintf(hdr, sizeof(hdr),
300 RAMOOPS_KERNMSG_HDR "%lld.%06lu-%c\n",
301 (time64_t)record->time.tv_sec,
302 record->time.tv_nsec / 1000,
303 record->compressed ? 'C' : 'D');
304 persistent_ram_write(prz, hdr, len);
305
306 return len;
307}
308
309static int notrace ramoops_pstore_write(struct pstore_record *record)
310{
311 struct ramoops_context *cxt = record->psi->data;
312 struct persistent_ram_zone *prz;
313 size_t size, hlen;
314
315 if (record->type == PSTORE_TYPE_CONSOLE) {
316 if (!cxt->cprz)
317 return -ENOMEM;
318 persistent_ram_write(cxt->cprz, record->buf, record->size);
319 return 0;
320 } else if (record->type == PSTORE_TYPE_FTRACE) {
321 int zonenum;
322
323 if (!cxt->fprzs)
324 return -ENOMEM;
325 /*
326 * Choose zone by if we're using per-cpu buffers.
327 */
328 if (cxt->flags & RAMOOPS_FLAG_FTRACE_PER_CPU)
329 zonenum = smp_processor_id();
330 else
331 zonenum = 0;
332
333 persistent_ram_write(cxt->fprzs[zonenum], record->buf,
334 record->size);
335 return 0;
336 } else if (record->type == PSTORE_TYPE_PMSG) {
337 pr_warn_ratelimited("PMSG shouldn't call %s\n", __func__);
338 return -EINVAL;
339 }
340
341 if (record->type != PSTORE_TYPE_DMESG)
342 return -EINVAL;
343
344 /*
345 * We could filter on record->reason here if we wanted to (which
346 * would duplicate what happened before the "max_reason" setting
347 * was added), but that would defeat the purpose of a system
348 * changing printk.always_kmsg_dump, so instead log everything that
349 * the kmsg dumper sends us, since it should be doing the filtering
350 * based on the combination of printk.always_kmsg_dump and our
351 * requested "max_reason".
352 */
353
354 /*
355 * Explicitly only take the first part of any new crash.
356 * If our buffer is larger than kmsg_bytes, this can never happen,
357 * and if our buffer is smaller than kmsg_bytes, we don't want the
358 * report split across multiple records.
359 */
360 if (record->part != 1)
361 return -ENOSPC;
362
363 if (!cxt->dprzs)
364 return -ENOSPC;
365
366 prz = cxt->dprzs[cxt->dump_write_cnt];
367
368 /*
369 * Since this is a new crash dump, we need to reset the buffer in
370 * case it still has an old dump present. Without this, the new dump
371 * will get appended, which would seriously confuse anything trying
372 * to check dump file contents. Specifically, ramoops_read_kmsg_hdr()
373 * expects to find a dump header in the beginning of buffer data, so
374 * we must to reset the buffer values, in order to ensure that the
375 * header will be written to the beginning of the buffer.
376 */
377 persistent_ram_zap(prz);
378
379 /* Build header and append record contents. */
380 hlen = ramoops_write_kmsg_hdr(prz, record);
381 if (!hlen)
382 return -ENOMEM;
383
384 size = record->size;
385 if (size + hlen > prz->buffer_size)
386 size = prz->buffer_size - hlen;
387 persistent_ram_write(prz, record->buf, size);
388
389 cxt->dump_write_cnt = (cxt->dump_write_cnt + 1) % cxt->max_dump_cnt;
390
391 return 0;
392}
393
394static int notrace ramoops_pstore_write_user(struct pstore_record *record,
395 const char __user *buf)
396{
397 if (record->type == PSTORE_TYPE_PMSG) {
398 struct ramoops_context *cxt = record->psi->data;
399
400 if (!cxt->mprz)
401 return -ENOMEM;
402 return persistent_ram_write_user(cxt->mprz, buf, record->size);
403 }
404
405 return -EINVAL;
406}
407
408static int ramoops_pstore_erase(struct pstore_record *record)
409{
410 struct ramoops_context *cxt = record->psi->data;
411 struct persistent_ram_zone *prz;
412
413 switch (record->type) {
414 case PSTORE_TYPE_DMESG:
415 if (record->id >= cxt->max_dump_cnt)
416 return -EINVAL;
417 prz = cxt->dprzs[record->id];
418 break;
419 case PSTORE_TYPE_CONSOLE:
420 prz = cxt->cprz;
421 break;
422 case PSTORE_TYPE_FTRACE:
423 if (record->id >= cxt->max_ftrace_cnt)
424 return -EINVAL;
425 prz = cxt->fprzs[record->id];
426 break;
427 case PSTORE_TYPE_PMSG:
428 prz = cxt->mprz;
429 break;
430 default:
431 return -EINVAL;
432 }
433
434 persistent_ram_free_old(prz);
435 persistent_ram_zap(prz);
436
437 return 0;
438}
439
440static struct ramoops_context oops_cxt = {
441 .pstore = {
442 .owner = THIS_MODULE,
443 .name = "ramoops",
444 .open = ramoops_pstore_open,
445 .read = ramoops_pstore_read,
446 .write = ramoops_pstore_write,
447 .write_user = ramoops_pstore_write_user,
448 .erase = ramoops_pstore_erase,
449 },
450};
451
452static void ramoops_free_przs(struct ramoops_context *cxt)
453{
454 int i;
455
456 /* Free pmsg PRZ */
457 persistent_ram_free(&cxt->mprz);
458
459 /* Free console PRZ */
460 persistent_ram_free(&cxt->cprz);
461
462 /* Free dump PRZs */
463 if (cxt->dprzs) {
464 for (i = 0; i < cxt->max_dump_cnt; i++)
465 persistent_ram_free(&cxt->dprzs[i]);
466
467 kfree(cxt->dprzs);
468 cxt->dprzs = NULL;
469 cxt->max_dump_cnt = 0;
470 }
471
472 /* Free ftrace PRZs */
473 if (cxt->fprzs) {
474 for (i = 0; i < cxt->max_ftrace_cnt; i++)
475 persistent_ram_free(&cxt->fprzs[i]);
476 kfree(cxt->fprzs);
477 cxt->fprzs = NULL;
478 cxt->max_ftrace_cnt = 0;
479 }
480}
481
482static int ramoops_init_przs(const char *name,
483 struct device *dev, struct ramoops_context *cxt,
484 struct persistent_ram_zone ***przs,
485 phys_addr_t *paddr, size_t mem_sz,
486 ssize_t record_size,
487 unsigned int *cnt, u32 sig, u32 flags)
488{
489 int err = -ENOMEM;
490 int i;
491 size_t zone_sz;
492 struct persistent_ram_zone **prz_ar;
493
494 /* Allocate nothing for 0 mem_sz or 0 record_size. */
495 if (mem_sz == 0 || record_size == 0) {
496 *cnt = 0;
497 return 0;
498 }
499
500 /*
501 * If we have a negative record size, calculate it based on
502 * mem_sz / *cnt. If we have a positive record size, calculate
503 * cnt from mem_sz / record_size.
504 */
505 if (record_size < 0) {
506 if (*cnt == 0)
507 return 0;
508 record_size = mem_sz / *cnt;
509 if (record_size == 0) {
510 dev_err(dev, "%s record size == 0 (%zu / %u)\n",
511 name, mem_sz, *cnt);
512 goto fail;
513 }
514 } else {
515 *cnt = mem_sz / record_size;
516 if (*cnt == 0) {
517 dev_err(dev, "%s record count == 0 (%zu / %zu)\n",
518 name, mem_sz, record_size);
519 goto fail;
520 }
521 }
522
523 if (*paddr + mem_sz - cxt->phys_addr > cxt->size) {
524 dev_err(dev, "no room for %s mem region (0x%zx@0x%llx) in (0x%lx@0x%llx)\n",
525 name,
526 mem_sz, (unsigned long long)*paddr,
527 cxt->size, (unsigned long long)cxt->phys_addr);
528 goto fail;
529 }
530
531 zone_sz = mem_sz / *cnt;
532 zone_sz = ALIGN_DOWN(zone_sz, 2);
533 if (!zone_sz) {
534 dev_err(dev, "%s zone size == 0\n", name);
535 goto fail;
536 }
537
538 prz_ar = kcalloc(*cnt, sizeof(**przs), GFP_KERNEL);
539 if (!prz_ar)
540 goto fail;
541
542 for (i = 0; i < *cnt; i++) {
543 char *label;
544
545 if (*cnt == 1)
546 label = kasprintf(GFP_KERNEL, "ramoops:%s", name);
547 else
548 label = kasprintf(GFP_KERNEL, "ramoops:%s(%d/%d)",
549 name, i, *cnt - 1);
550 prz_ar[i] = persistent_ram_new(*paddr, zone_sz, sig,
551 &cxt->ecc_info,
552 cxt->memtype, flags, label);
553 kfree(label);
554 if (IS_ERR(prz_ar[i])) {
555 err = PTR_ERR(prz_ar[i]);
556 dev_err(dev, "failed to request %s mem region (0x%zx@0x%llx): %d\n",
557 name, record_size,
558 (unsigned long long)*paddr, err);
559
560 while (i > 0) {
561 i--;
562 persistent_ram_free(&prz_ar[i]);
563 }
564 kfree(prz_ar);
565 prz_ar = NULL;
566 goto fail;
567 }
568 *paddr += zone_sz;
569 prz_ar[i]->type = pstore_name_to_type(name);
570 }
571
572 *przs = prz_ar;
573 return 0;
574
575fail:
576 *cnt = 0;
577 return err;
578}
579
580static int ramoops_init_prz(const char *name,
581 struct device *dev, struct ramoops_context *cxt,
582 struct persistent_ram_zone **prz,
583 phys_addr_t *paddr, size_t sz, u32 sig)
584{
585 char *label;
586
587 if (!sz)
588 return 0;
589
590 if (*paddr + sz - cxt->phys_addr > cxt->size) {
591 dev_err(dev, "no room for %s mem region (0x%zx@0x%llx) in (0x%lx@0x%llx)\n",
592 name, sz, (unsigned long long)*paddr,
593 cxt->size, (unsigned long long)cxt->phys_addr);
594 return -ENOMEM;
595 }
596
597 label = kasprintf(GFP_KERNEL, "ramoops:%s", name);
598 *prz = persistent_ram_new(*paddr, sz, sig, &cxt->ecc_info,
599 cxt->memtype, PRZ_FLAG_ZAP_OLD, label);
600 kfree(label);
601 if (IS_ERR(*prz)) {
602 int err = PTR_ERR(*prz);
603
604 dev_err(dev, "failed to request %s mem region (0x%zx@0x%llx): %d\n",
605 name, sz, (unsigned long long)*paddr, err);
606 return err;
607 }
608
609 *paddr += sz;
610 (*prz)->type = pstore_name_to_type(name);
611
612 return 0;
613}
614
615/* Read a u32 from a dt property and make sure it's safe for an int. */
616static int ramoops_parse_dt_u32(struct platform_device *pdev,
617 const char *propname,
618 u32 default_value, u32 *value)
619{
620 u32 val32 = 0;
621 int ret;
622
623 ret = of_property_read_u32(pdev->dev.of_node, propname, &val32);
624 if (ret == -EINVAL) {
625 /* field is missing, use default value. */
626 val32 = default_value;
627 } else if (ret < 0) {
628 dev_err(&pdev->dev, "failed to parse property %s: %d\n",
629 propname, ret);
630 return ret;
631 }
632
633 /* Sanity check our results. */
634 if (val32 > INT_MAX) {
635 dev_err(&pdev->dev, "%s %u > INT_MAX\n", propname, val32);
636 return -EOVERFLOW;
637 }
638
639 *value = val32;
640 return 0;
641}
642
643static int ramoops_parse_dt(struct platform_device *pdev,
644 struct ramoops_platform_data *pdata)
645{
646 struct device_node *of_node = pdev->dev.of_node;
647 struct device_node *parent_node;
648 struct resource *res;
649 u32 value;
650 int ret;
651
652 dev_dbg(&pdev->dev, "using Device Tree\n");
653
654 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
655 if (!res) {
656 dev_err(&pdev->dev,
657 "failed to locate DT /reserved-memory resource\n");
658 return -EINVAL;
659 }
660
661 pdata->mem_size = resource_size(res);
662 pdata->mem_address = res->start;
663 /*
664 * Setting "unbuffered" is deprecated and will be ignored if
665 * "mem_type" is also specified.
666 */
667 pdata->mem_type = of_property_read_bool(of_node, "unbuffered");
668 /*
669 * Setting "no-dump-oops" is deprecated and will be ignored if
670 * "max_reason" is also specified.
671 */
672 if (of_property_read_bool(of_node, "no-dump-oops"))
673 pdata->max_reason = KMSG_DUMP_PANIC;
674 else
675 pdata->max_reason = KMSG_DUMP_OOPS;
676
677#define parse_u32(name, field, default_value) { \
678 ret = ramoops_parse_dt_u32(pdev, name, default_value, \
679 &value); \
680 if (ret < 0) \
681 return ret; \
682 field = value; \
683 }
684
685 parse_u32("mem-type", pdata->mem_type, pdata->mem_type);
686 parse_u32("record-size", pdata->record_size, 0);
687 parse_u32("console-size", pdata->console_size, 0);
688 parse_u32("ftrace-size", pdata->ftrace_size, 0);
689 parse_u32("pmsg-size", pdata->pmsg_size, 0);
690 parse_u32("ecc-size", pdata->ecc_info.ecc_size, 0);
691 parse_u32("flags", pdata->flags, 0);
692 parse_u32("max-reason", pdata->max_reason, pdata->max_reason);
693
694#undef parse_u32
695
696 /*
697 * Some old Chromebooks relied on the kernel setting the
698 * console_size and pmsg_size to the record size since that's
699 * what the downstream kernel did. These same Chromebooks had
700 * "ramoops" straight under the root node which isn't
701 * according to the current upstream bindings (though it was
702 * arguably acceptable under a prior version of the bindings).
703 * Let's make those old Chromebooks work by detecting that
704 * we're not a child of "reserved-memory" and mimicking the
705 * expected behavior.
706 */
707 parent_node = of_get_parent(of_node);
708 if (!of_node_name_eq(parent_node, "reserved-memory") &&
709 !pdata->console_size && !pdata->ftrace_size &&
710 !pdata->pmsg_size && !pdata->ecc_info.ecc_size) {
711 pdata->console_size = pdata->record_size;
712 pdata->pmsg_size = pdata->record_size;
713 }
714 of_node_put(parent_node);
715
716 return 0;
717}
718
719static int ramoops_probe(struct platform_device *pdev)
720{
721 struct device *dev = &pdev->dev;
722 struct ramoops_platform_data *pdata = dev->platform_data;
723 struct ramoops_platform_data pdata_local;
724 struct ramoops_context *cxt = &oops_cxt;
725 size_t dump_mem_sz;
726 phys_addr_t paddr;
727 int err = -EINVAL;
728
729 /*
730 * Only a single ramoops area allowed at a time, so fail extra
731 * probes.
732 */
733 if (cxt->max_dump_cnt) {
734 pr_err("already initialized\n");
735 goto fail_out;
736 }
737
738 if (dev_of_node(dev) && !pdata) {
739 pdata = &pdata_local;
740 memset(pdata, 0, sizeof(*pdata));
741
742 err = ramoops_parse_dt(pdev, pdata);
743 if (err < 0)
744 goto fail_out;
745 }
746
747 /* Make sure we didn't get bogus platform data pointer. */
748 if (!pdata) {
749 pr_err("NULL platform data\n");
750 err = -EINVAL;
751 goto fail_out;
752 }
753
754 if (!pdata->mem_size || (!pdata->record_size && !pdata->console_size &&
755 !pdata->ftrace_size && !pdata->pmsg_size)) {
756 pr_err("The memory size and the record/console size must be "
757 "non-zero\n");
758 err = -EINVAL;
759 goto fail_out;
760 }
761
762 if (pdata->record_size && !is_power_of_2(pdata->record_size))
763 pdata->record_size = rounddown_pow_of_two(pdata->record_size);
764 if (pdata->console_size && !is_power_of_2(pdata->console_size))
765 pdata->console_size = rounddown_pow_of_two(pdata->console_size);
766 if (pdata->ftrace_size && !is_power_of_2(pdata->ftrace_size))
767 pdata->ftrace_size = rounddown_pow_of_two(pdata->ftrace_size);
768 if (pdata->pmsg_size && !is_power_of_2(pdata->pmsg_size))
769 pdata->pmsg_size = rounddown_pow_of_two(pdata->pmsg_size);
770
771 cxt->size = pdata->mem_size;
772 cxt->phys_addr = pdata->mem_address;
773 cxt->memtype = pdata->mem_type;
774 cxt->record_size = pdata->record_size;
775 cxt->console_size = pdata->console_size;
776 cxt->ftrace_size = pdata->ftrace_size;
777 cxt->pmsg_size = pdata->pmsg_size;
778 cxt->flags = pdata->flags;
779 cxt->ecc_info = pdata->ecc_info;
780
781 paddr = cxt->phys_addr;
782
783 dump_mem_sz = cxt->size - cxt->console_size - cxt->ftrace_size
784 - cxt->pmsg_size;
785 err = ramoops_init_przs("dmesg", dev, cxt, &cxt->dprzs, &paddr,
786 dump_mem_sz, cxt->record_size,
787 &cxt->max_dump_cnt, 0, 0);
788 if (err)
789 goto fail_init;
790
791 err = ramoops_init_prz("console", dev, cxt, &cxt->cprz, &paddr,
792 cxt->console_size, 0);
793 if (err)
794 goto fail_init;
795
796 err = ramoops_init_prz("pmsg", dev, cxt, &cxt->mprz, &paddr,
797 cxt->pmsg_size, 0);
798 if (err)
799 goto fail_init;
800
801 cxt->max_ftrace_cnt = (cxt->flags & RAMOOPS_FLAG_FTRACE_PER_CPU)
802 ? nr_cpu_ids
803 : 1;
804 err = ramoops_init_przs("ftrace", dev, cxt, &cxt->fprzs, &paddr,
805 cxt->ftrace_size, -1,
806 &cxt->max_ftrace_cnt, LINUX_VERSION_CODE,
807 (cxt->flags & RAMOOPS_FLAG_FTRACE_PER_CPU)
808 ? PRZ_FLAG_NO_LOCK : 0);
809 if (err)
810 goto fail_init;
811
812 cxt->pstore.data = cxt;
813 /*
814 * Prepare frontend flags based on which areas are initialized.
815 * For ramoops_init_przs() cases, the "max count" variable tells
816 * if there are regions present. For ramoops_init_prz() cases,
817 * the single region size is how to check.
818 */
819 cxt->pstore.flags = 0;
820 if (cxt->max_dump_cnt) {
821 cxt->pstore.flags |= PSTORE_FLAGS_DMESG;
822 cxt->pstore.max_reason = pdata->max_reason;
823 }
824 if (cxt->console_size)
825 cxt->pstore.flags |= PSTORE_FLAGS_CONSOLE;
826 if (cxt->max_ftrace_cnt)
827 cxt->pstore.flags |= PSTORE_FLAGS_FTRACE;
828 if (cxt->pmsg_size)
829 cxt->pstore.flags |= PSTORE_FLAGS_PMSG;
830
831 /*
832 * Since bufsize is only used for dmesg crash dumps, it
833 * must match the size of the dprz record (after PRZ header
834 * and ECC bytes have been accounted for).
835 */
836 if (cxt->pstore.flags & PSTORE_FLAGS_DMESG) {
837 cxt->pstore.bufsize = cxt->dprzs[0]->buffer_size;
838 cxt->pstore.buf = kvzalloc(cxt->pstore.bufsize, GFP_KERNEL);
839 if (!cxt->pstore.buf) {
840 pr_err("cannot allocate pstore crash dump buffer\n");
841 err = -ENOMEM;
842 goto fail_clear;
843 }
844 }
845
846 err = pstore_register(&cxt->pstore);
847 if (err) {
848 pr_err("registering with pstore failed\n");
849 goto fail_buf;
850 }
851
852 /*
853 * Update the module parameter variables as well so they are visible
854 * through /sys/module/ramoops/parameters/
855 */
856 mem_size = pdata->mem_size;
857 mem_address = pdata->mem_address;
858 record_size = pdata->record_size;
859 ramoops_max_reason = pdata->max_reason;
860 ramoops_console_size = pdata->console_size;
861 ramoops_pmsg_size = pdata->pmsg_size;
862 ramoops_ftrace_size = pdata->ftrace_size;
863
864 pr_info("using 0x%lx@0x%llx, ecc: %d\n",
865 cxt->size, (unsigned long long)cxt->phys_addr,
866 cxt->ecc_info.ecc_size);
867
868 return 0;
869
870fail_buf:
871 kvfree(cxt->pstore.buf);
872fail_clear:
873 cxt->pstore.bufsize = 0;
874fail_init:
875 ramoops_free_przs(cxt);
876fail_out:
877 return err;
878}
879
880static void ramoops_remove(struct platform_device *pdev)
881{
882 struct ramoops_context *cxt = &oops_cxt;
883
884 pstore_unregister(&cxt->pstore);
885
886 kvfree(cxt->pstore.buf);
887 cxt->pstore.bufsize = 0;
888
889 ramoops_free_przs(cxt);
890}
891
892static const struct of_device_id dt_match[] = {
893 { .compatible = "ramoops" },
894 {}
895};
896
897static struct platform_driver ramoops_driver = {
898 .probe = ramoops_probe,
899 .remove_new = ramoops_remove,
900 .driver = {
901 .name = "ramoops",
902 .of_match_table = dt_match,
903 },
904};
905
906static inline void ramoops_unregister_dummy(void)
907{
908 platform_device_unregister(dummy);
909 dummy = NULL;
910}
911
912static void __init ramoops_register_dummy(void)
913{
914 struct ramoops_platform_data pdata;
915
916 /*
917 * Prepare a dummy platform data structure to carry the module
918 * parameters. If mem_size isn't set, then there are no module
919 * parameters, and we can skip this.
920 */
921 if (!mem_size)
922 return;
923
924 pr_info("using module parameters\n");
925
926 memset(&pdata, 0, sizeof(pdata));
927 pdata.mem_size = mem_size;
928 pdata.mem_address = mem_address;
929 pdata.mem_type = mem_type;
930 pdata.record_size = record_size;
931 pdata.console_size = ramoops_console_size;
932 pdata.ftrace_size = ramoops_ftrace_size;
933 pdata.pmsg_size = ramoops_pmsg_size;
934 /* If "max_reason" is set, its value has priority over "dump_oops". */
935 if (ramoops_max_reason >= 0)
936 pdata.max_reason = ramoops_max_reason;
937 /* Otherwise, if "dump_oops" is set, parse it into "max_reason". */
938 else if (ramoops_dump_oops != -1)
939 pdata.max_reason = ramoops_dump_oops ? KMSG_DUMP_OOPS
940 : KMSG_DUMP_PANIC;
941 /* And if neither are explicitly set, use the default. */
942 else
943 pdata.max_reason = KMSG_DUMP_OOPS;
944 pdata.flags = RAMOOPS_FLAG_FTRACE_PER_CPU;
945
946 /*
947 * For backwards compatibility ramoops.ecc=1 means 16 bytes ECC
948 * (using 1 byte for ECC isn't much of use anyway).
949 */
950 pdata.ecc_info.ecc_size = ramoops_ecc == 1 ? 16 : ramoops_ecc;
951
952 dummy = platform_device_register_data(NULL, "ramoops", -1,
953 &pdata, sizeof(pdata));
954 if (IS_ERR(dummy)) {
955 pr_info("could not create platform device: %ld\n",
956 PTR_ERR(dummy));
957 dummy = NULL;
958 }
959}
960
961static int __init ramoops_init(void)
962{
963 int ret;
964
965 ramoops_register_dummy();
966 ret = platform_driver_register(&ramoops_driver);
967 if (ret != 0)
968 ramoops_unregister_dummy();
969
970 return ret;
971}
972postcore_initcall(ramoops_init);
973
974static void __exit ramoops_exit(void)
975{
976 platform_driver_unregister(&ramoops_driver);
977 ramoops_unregister_dummy();
978}
979module_exit(ramoops_exit);
980
981MODULE_LICENSE("GPL");
982MODULE_AUTHOR("Marco Stornelli <marco.stornelli@gmail.com>");
983MODULE_DESCRIPTION("RAM Oops/Panic logger/driver");
1/*
2 * RAM Oops/Panic logger
3 *
4 * Copyright (C) 2010 Marco Stornelli <marco.stornelli@gmail.com>
5 * Copyright (C) 2011 Kees Cook <keescook@chromium.org>
6 *
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.
10 *
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.
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., 51 Franklin St, Fifth Floor, Boston, MA
19 * 02110-1301 USA
20 *
21 */
22
23#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
24
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>
37#include <linux/of.h>
38#include <linux/of_address.h>
39
40#define RAMOOPS_KERNMSG_HDR "===="
41#define MIN_MEM_SIZE 4096UL
42
43static ulong record_size = MIN_MEM_SIZE;
44module_param(record_size, ulong, 0400);
45MODULE_PARM_DESC(record_size,
46 "size of each dump done on oops/panic");
47
48static ulong ramoops_console_size = MIN_MEM_SIZE;
49module_param_named(console_size, ramoops_console_size, ulong, 0400);
50MODULE_PARM_DESC(console_size, "size of kernel console log");
51
52static ulong ramoops_ftrace_size = MIN_MEM_SIZE;
53module_param_named(ftrace_size, ramoops_ftrace_size, ulong, 0400);
54MODULE_PARM_DESC(ftrace_size, "size of ftrace log");
55
56static ulong ramoops_pmsg_size = MIN_MEM_SIZE;
57module_param_named(pmsg_size, ramoops_pmsg_size, ulong, 0400);
58MODULE_PARM_DESC(pmsg_size, "size of user space message log");
59
60static unsigned long long mem_address;
61module_param(mem_address, ullong, 0400);
62MODULE_PARM_DESC(mem_address,
63 "start of reserved RAM used to store oops/panic logs");
64
65static ulong mem_size;
66module_param(mem_size, ulong, 0400);
67MODULE_PARM_DESC(mem_size,
68 "size of reserved RAM used to store oops/panic logs");
69
70static unsigned int mem_type;
71module_param(mem_type, uint, 0600);
72MODULE_PARM_DESC(mem_type,
73 "set to 1 to try to use unbuffered memory (default 0)");
74
75static int dump_oops = 1;
76module_param(dump_oops, int, 0600);
77MODULE_PARM_DESC(dump_oops,
78 "set to 1 to dump oopses, 0 to only dump panics (default 1)");
79
80static int ramoops_ecc;
81module_param_named(ecc, ramoops_ecc, int, 0600);
82MODULE_PARM_DESC(ramoops_ecc,
83 "if non-zero, the option enables ECC support and specifies "
84 "ECC buffer size in bytes (1 is a special value, means 16 "
85 "bytes ECC)");
86
87struct ramoops_context {
88 struct persistent_ram_zone **dprzs; /* Oops dump zones */
89 struct persistent_ram_zone *cprz; /* Console zone */
90 struct persistent_ram_zone **fprzs; /* Ftrace zones */
91 struct persistent_ram_zone *mprz; /* PMSG zone */
92 phys_addr_t phys_addr;
93 unsigned long size;
94 unsigned int memtype;
95 size_t record_size;
96 size_t console_size;
97 size_t ftrace_size;
98 size_t pmsg_size;
99 int dump_oops;
100 u32 flags;
101 struct persistent_ram_ecc_info ecc_info;
102 unsigned int max_dump_cnt;
103 unsigned int dump_write_cnt;
104 /* _read_cnt need clear on ramoops_pstore_open */
105 unsigned int dump_read_cnt;
106 unsigned int console_read_cnt;
107 unsigned int max_ftrace_cnt;
108 unsigned int ftrace_read_cnt;
109 unsigned int pmsg_read_cnt;
110 struct pstore_info pstore;
111};
112
113static struct platform_device *dummy;
114static struct ramoops_platform_data *dummy_data;
115
116static int ramoops_pstore_open(struct pstore_info *psi)
117{
118 struct ramoops_context *cxt = psi->data;
119
120 cxt->dump_read_cnt = 0;
121 cxt->console_read_cnt = 0;
122 cxt->ftrace_read_cnt = 0;
123 cxt->pmsg_read_cnt = 0;
124 return 0;
125}
126
127static struct persistent_ram_zone *
128ramoops_get_next_prz(struct persistent_ram_zone *przs[], uint *c, uint max,
129 u64 *id,
130 enum pstore_type_id *typep, enum pstore_type_id type,
131 bool update)
132{
133 struct persistent_ram_zone *prz;
134 int i = (*c)++;
135
136 if (i >= max)
137 return NULL;
138
139 prz = przs[i];
140 if (!prz)
141 return NULL;
142
143 /* Update old/shadowed buffer. */
144 if (update)
145 persistent_ram_save_old(prz);
146
147 if (!persistent_ram_old_size(prz))
148 return NULL;
149
150 *typep = type;
151 *id = i;
152
153 return prz;
154}
155
156static int ramoops_read_kmsg_hdr(char *buffer, struct timespec *time,
157 bool *compressed)
158{
159 char data_type;
160 int header_length = 0;
161
162 if (sscanf(buffer, RAMOOPS_KERNMSG_HDR "%lu.%lu-%c\n%n", &time->tv_sec,
163 &time->tv_nsec, &data_type, &header_length) == 3) {
164 if (data_type == 'C')
165 *compressed = true;
166 else
167 *compressed = false;
168 } else if (sscanf(buffer, RAMOOPS_KERNMSG_HDR "%lu.%lu\n%n",
169 &time->tv_sec, &time->tv_nsec, &header_length) == 2) {
170 *compressed = false;
171 } else {
172 time->tv_sec = 0;
173 time->tv_nsec = 0;
174 *compressed = false;
175 }
176 return header_length;
177}
178
179static bool prz_ok(struct persistent_ram_zone *prz)
180{
181 return !!prz && !!(persistent_ram_old_size(prz) +
182 persistent_ram_ecc_string(prz, NULL, 0));
183}
184
185static ssize_t ftrace_log_combine(struct persistent_ram_zone *dest,
186 struct persistent_ram_zone *src)
187{
188 size_t dest_size, src_size, total, dest_off, src_off;
189 size_t dest_idx = 0, src_idx = 0, merged_idx = 0;
190 void *merged_buf;
191 struct pstore_ftrace_record *drec, *srec, *mrec;
192 size_t record_size = sizeof(struct pstore_ftrace_record);
193
194 dest_off = dest->old_log_size % record_size;
195 dest_size = dest->old_log_size - dest_off;
196
197 src_off = src->old_log_size % record_size;
198 src_size = src->old_log_size - src_off;
199
200 total = dest_size + src_size;
201 merged_buf = kmalloc(total, GFP_KERNEL);
202 if (!merged_buf)
203 return -ENOMEM;
204
205 drec = (struct pstore_ftrace_record *)(dest->old_log + dest_off);
206 srec = (struct pstore_ftrace_record *)(src->old_log + src_off);
207 mrec = (struct pstore_ftrace_record *)(merged_buf);
208
209 while (dest_size > 0 && src_size > 0) {
210 if (pstore_ftrace_read_timestamp(&drec[dest_idx]) <
211 pstore_ftrace_read_timestamp(&srec[src_idx])) {
212 mrec[merged_idx++] = drec[dest_idx++];
213 dest_size -= record_size;
214 } else {
215 mrec[merged_idx++] = srec[src_idx++];
216 src_size -= record_size;
217 }
218 }
219
220 while (dest_size > 0) {
221 mrec[merged_idx++] = drec[dest_idx++];
222 dest_size -= record_size;
223 }
224
225 while (src_size > 0) {
226 mrec[merged_idx++] = srec[src_idx++];
227 src_size -= record_size;
228 }
229
230 kfree(dest->old_log);
231 dest->old_log = merged_buf;
232 dest->old_log_size = total;
233
234 return 0;
235}
236
237static ssize_t ramoops_pstore_read(u64 *id, enum pstore_type_id *type,
238 int *count, struct timespec *time,
239 char **buf, bool *compressed,
240 ssize_t *ecc_notice_size,
241 struct pstore_info *psi)
242{
243 ssize_t size = 0;
244 struct ramoops_context *cxt = psi->data;
245 struct persistent_ram_zone *prz = NULL;
246 int header_length = 0;
247 bool free_prz = false;
248
249 /* Ramoops headers provide time stamps for PSTORE_TYPE_DMESG, but
250 * PSTORE_TYPE_CONSOLE and PSTORE_TYPE_FTRACE don't currently have
251 * valid time stamps, so it is initialized to zero.
252 */
253 time->tv_sec = 0;
254 time->tv_nsec = 0;
255 *compressed = false;
256
257 /* Find the next valid persistent_ram_zone for DMESG */
258 while (cxt->dump_read_cnt < cxt->max_dump_cnt && !prz) {
259 prz = ramoops_get_next_prz(cxt->dprzs, &cxt->dump_read_cnt,
260 cxt->max_dump_cnt, id, type,
261 PSTORE_TYPE_DMESG, 1);
262 if (!prz_ok(prz))
263 continue;
264 header_length = ramoops_read_kmsg_hdr(persistent_ram_old(prz),
265 time, compressed);
266 /* Clear and skip this DMESG record if it has no valid header */
267 if (!header_length) {
268 persistent_ram_free_old(prz);
269 persistent_ram_zap(prz);
270 prz = NULL;
271 }
272 }
273
274 if (!prz_ok(prz))
275 prz = ramoops_get_next_prz(&cxt->cprz, &cxt->console_read_cnt,
276 1, id, type, PSTORE_TYPE_CONSOLE, 0);
277
278 if (!prz_ok(prz))
279 prz = ramoops_get_next_prz(&cxt->mprz, &cxt->pmsg_read_cnt,
280 1, id, type, PSTORE_TYPE_PMSG, 0);
281
282 /* ftrace is last since it may want to dynamically allocate memory. */
283 if (!prz_ok(prz) && cxt->fprzs) {
284 if (!(cxt->flags & RAMOOPS_FLAG_FTRACE_PER_CPU)) {
285 prz = ramoops_get_next_prz(cxt->fprzs,
286 &cxt->ftrace_read_cnt, 1, id, type,
287 PSTORE_TYPE_FTRACE, 0);
288 } else {
289 /*
290 * Build a new dummy record which combines all the
291 * per-cpu records including metadata and ecc info.
292 */
293 struct persistent_ram_zone *tmp_prz, *prz_next;
294
295 tmp_prz = kzalloc(sizeof(struct persistent_ram_zone),
296 GFP_KERNEL);
297 if (!tmp_prz)
298 return -ENOMEM;
299 free_prz = true;
300
301 while (cxt->ftrace_read_cnt < cxt->max_ftrace_cnt) {
302 prz_next = ramoops_get_next_prz(cxt->fprzs,
303 &cxt->ftrace_read_cnt,
304 cxt->max_ftrace_cnt, id,
305 type, PSTORE_TYPE_FTRACE, 0);
306
307 if (!prz_ok(prz_next))
308 continue;
309
310 tmp_prz->ecc_info = prz_next->ecc_info;
311 tmp_prz->corrected_bytes +=
312 prz_next->corrected_bytes;
313 tmp_prz->bad_blocks += prz_next->bad_blocks;
314 size = ftrace_log_combine(tmp_prz, prz_next);
315 if (size)
316 goto out;
317 }
318 *id = 0;
319 prz = tmp_prz;
320 }
321 }
322
323 if (!prz_ok(prz)) {
324 size = 0;
325 goto out;
326 }
327
328 size = persistent_ram_old_size(prz) - header_length;
329
330 /* ECC correction notice */
331 *ecc_notice_size = persistent_ram_ecc_string(prz, NULL, 0);
332
333 *buf = kmalloc(size + *ecc_notice_size + 1, GFP_KERNEL);
334 if (*buf == NULL) {
335 size = -ENOMEM;
336 goto out;
337 }
338
339 memcpy(*buf, (char *)persistent_ram_old(prz) + header_length, size);
340
341 persistent_ram_ecc_string(prz, *buf + size, *ecc_notice_size + 1);
342
343out:
344 if (free_prz) {
345 kfree(prz->old_log);
346 kfree(prz);
347 }
348
349 return size;
350}
351
352static size_t ramoops_write_kmsg_hdr(struct persistent_ram_zone *prz,
353 bool compressed)
354{
355 char *hdr;
356 struct timespec timestamp;
357 size_t len;
358
359 /* Report zeroed timestamp if called before timekeeping has resumed. */
360 if (__getnstimeofday(×tamp)) {
361 timestamp.tv_sec = 0;
362 timestamp.tv_nsec = 0;
363 }
364 hdr = kasprintf(GFP_ATOMIC, RAMOOPS_KERNMSG_HDR "%lu.%lu-%c\n",
365 (long)timestamp.tv_sec, (long)(timestamp.tv_nsec / 1000),
366 compressed ? 'C' : 'D');
367 WARN_ON_ONCE(!hdr);
368 len = hdr ? strlen(hdr) : 0;
369 persistent_ram_write(prz, hdr, len);
370 kfree(hdr);
371
372 return len;
373}
374
375static int notrace ramoops_pstore_write_buf(enum pstore_type_id type,
376 enum kmsg_dump_reason reason,
377 u64 *id, unsigned int part,
378 const char *buf,
379 bool compressed, size_t size,
380 struct pstore_info *psi)
381{
382 struct ramoops_context *cxt = psi->data;
383 struct persistent_ram_zone *prz;
384 size_t hlen;
385
386 if (type == PSTORE_TYPE_CONSOLE) {
387 if (!cxt->cprz)
388 return -ENOMEM;
389 persistent_ram_write(cxt->cprz, buf, size);
390 return 0;
391 } else if (type == PSTORE_TYPE_FTRACE) {
392 int zonenum;
393
394 if (!cxt->fprzs)
395 return -ENOMEM;
396 /*
397 * Choose zone by if we're using per-cpu buffers.
398 */
399 if (cxt->flags & RAMOOPS_FLAG_FTRACE_PER_CPU)
400 zonenum = smp_processor_id();
401 else
402 zonenum = 0;
403
404 persistent_ram_write(cxt->fprzs[zonenum], buf, size);
405 return 0;
406 } else if (type == PSTORE_TYPE_PMSG) {
407 pr_warn_ratelimited("PMSG shouldn't call %s\n", __func__);
408 return -EINVAL;
409 }
410
411 if (type != PSTORE_TYPE_DMESG)
412 return -EINVAL;
413
414 /* Out of the various dmesg dump types, ramoops is currently designed
415 * to only store crash logs, rather than storing general kernel logs.
416 */
417 if (reason != KMSG_DUMP_OOPS &&
418 reason != KMSG_DUMP_PANIC)
419 return -EINVAL;
420
421 /* Skip Oopes when configured to do so. */
422 if (reason == KMSG_DUMP_OOPS && !cxt->dump_oops)
423 return -EINVAL;
424
425 /* Explicitly only take the first part of any new crash.
426 * If our buffer is larger than kmsg_bytes, this can never happen,
427 * and if our buffer is smaller than kmsg_bytes, we don't want the
428 * report split across multiple records.
429 */
430 if (part != 1)
431 return -ENOSPC;
432
433 if (!cxt->dprzs)
434 return -ENOSPC;
435
436 prz = cxt->dprzs[cxt->dump_write_cnt];
437
438 hlen = ramoops_write_kmsg_hdr(prz, compressed);
439 if (size + hlen > prz->buffer_size)
440 size = prz->buffer_size - hlen;
441 persistent_ram_write(prz, buf, size);
442
443 cxt->dump_write_cnt = (cxt->dump_write_cnt + 1) % cxt->max_dump_cnt;
444
445 return 0;
446}
447
448static int notrace ramoops_pstore_write_buf_user(enum pstore_type_id type,
449 enum kmsg_dump_reason reason,
450 u64 *id, unsigned int part,
451 const char __user *buf,
452 bool compressed, size_t size,
453 struct pstore_info *psi)
454{
455 if (type == PSTORE_TYPE_PMSG) {
456 struct ramoops_context *cxt = psi->data;
457
458 if (!cxt->mprz)
459 return -ENOMEM;
460 return persistent_ram_write_user(cxt->mprz, buf, size);
461 }
462
463 return -EINVAL;
464}
465
466static int ramoops_pstore_erase(enum pstore_type_id type, u64 id, int count,
467 struct timespec time, struct pstore_info *psi)
468{
469 struct ramoops_context *cxt = psi->data;
470 struct persistent_ram_zone *prz;
471
472 switch (type) {
473 case PSTORE_TYPE_DMESG:
474 if (id >= cxt->max_dump_cnt)
475 return -EINVAL;
476 prz = cxt->dprzs[id];
477 break;
478 case PSTORE_TYPE_CONSOLE:
479 prz = cxt->cprz;
480 break;
481 case PSTORE_TYPE_FTRACE:
482 if (id >= cxt->max_ftrace_cnt)
483 return -EINVAL;
484 prz = cxt->fprzs[id];
485 break;
486 case PSTORE_TYPE_PMSG:
487 prz = cxt->mprz;
488 break;
489 default:
490 return -EINVAL;
491 }
492
493 persistent_ram_free_old(prz);
494 persistent_ram_zap(prz);
495
496 return 0;
497}
498
499static struct ramoops_context oops_cxt = {
500 .pstore = {
501 .owner = THIS_MODULE,
502 .name = "ramoops",
503 .open = ramoops_pstore_open,
504 .read = ramoops_pstore_read,
505 .write_buf = ramoops_pstore_write_buf,
506 .write_buf_user = ramoops_pstore_write_buf_user,
507 .erase = ramoops_pstore_erase,
508 },
509};
510
511static void ramoops_free_przs(struct ramoops_context *cxt)
512{
513 int i;
514
515 /* Free dump PRZs */
516 if (cxt->dprzs) {
517 for (i = 0; i < cxt->max_dump_cnt; i++)
518 persistent_ram_free(cxt->dprzs[i]);
519
520 kfree(cxt->dprzs);
521 cxt->max_dump_cnt = 0;
522 }
523
524 /* Free ftrace PRZs */
525 if (cxt->fprzs) {
526 for (i = 0; i < cxt->max_ftrace_cnt; i++)
527 persistent_ram_free(cxt->fprzs[i]);
528 kfree(cxt->fprzs);
529 cxt->max_ftrace_cnt = 0;
530 }
531}
532
533static int ramoops_init_przs(const char *name,
534 struct device *dev, struct ramoops_context *cxt,
535 struct persistent_ram_zone ***przs,
536 phys_addr_t *paddr, size_t mem_sz,
537 ssize_t record_size,
538 unsigned int *cnt, u32 sig, u32 flags)
539{
540 int err = -ENOMEM;
541 int i;
542 size_t zone_sz;
543 struct persistent_ram_zone **prz_ar;
544
545 /* Allocate nothing for 0 mem_sz or 0 record_size. */
546 if (mem_sz == 0 || record_size == 0) {
547 *cnt = 0;
548 return 0;
549 }
550
551 /*
552 * If we have a negative record size, calculate it based on
553 * mem_sz / *cnt. If we have a positive record size, calculate
554 * cnt from mem_sz / record_size.
555 */
556 if (record_size < 0) {
557 if (*cnt == 0)
558 return 0;
559 record_size = mem_sz / *cnt;
560 if (record_size == 0) {
561 dev_err(dev, "%s record size == 0 (%zu / %u)\n",
562 name, mem_sz, *cnt);
563 goto fail;
564 }
565 } else {
566 *cnt = mem_sz / record_size;
567 if (*cnt == 0) {
568 dev_err(dev, "%s record count == 0 (%zu / %zu)\n",
569 name, mem_sz, record_size);
570 goto fail;
571 }
572 }
573
574 if (*paddr + mem_sz - cxt->phys_addr > cxt->size) {
575 dev_err(dev, "no room for %s mem region (0x%zx@0x%llx) in (0x%lx@0x%llx)\n",
576 name,
577 mem_sz, (unsigned long long)*paddr,
578 cxt->size, (unsigned long long)cxt->phys_addr);
579 goto fail;
580 }
581
582 zone_sz = mem_sz / *cnt;
583 if (!zone_sz) {
584 dev_err(dev, "%s zone size == 0\n", name);
585 goto fail;
586 }
587
588 prz_ar = kcalloc(*cnt, sizeof(**przs), GFP_KERNEL);
589 if (!prz_ar)
590 goto fail;
591
592 for (i = 0; i < *cnt; i++) {
593 prz_ar[i] = persistent_ram_new(*paddr, zone_sz, sig,
594 &cxt->ecc_info,
595 cxt->memtype, flags);
596 if (IS_ERR(prz_ar[i])) {
597 err = PTR_ERR(prz_ar[i]);
598 dev_err(dev, "failed to request %s mem region (0x%zx@0x%llx): %d\n",
599 name, record_size,
600 (unsigned long long)*paddr, err);
601
602 while (i > 0) {
603 i--;
604 persistent_ram_free(prz_ar[i]);
605 }
606 kfree(prz_ar);
607 goto fail;
608 }
609 *paddr += zone_sz;
610 }
611
612 *przs = prz_ar;
613 return 0;
614
615fail:
616 *cnt = 0;
617 return err;
618}
619
620static int ramoops_init_prz(const char *name,
621 struct device *dev, struct ramoops_context *cxt,
622 struct persistent_ram_zone **prz,
623 phys_addr_t *paddr, size_t sz, u32 sig)
624{
625 if (!sz)
626 return 0;
627
628 if (*paddr + sz - cxt->phys_addr > cxt->size) {
629 dev_err(dev, "no room for %s mem region (0x%zx@0x%llx) in (0x%lx@0x%llx)\n",
630 name, sz, (unsigned long long)*paddr,
631 cxt->size, (unsigned long long)cxt->phys_addr);
632 return -ENOMEM;
633 }
634
635 *prz = persistent_ram_new(*paddr, sz, sig, &cxt->ecc_info,
636 cxt->memtype, 0);
637 if (IS_ERR(*prz)) {
638 int err = PTR_ERR(*prz);
639
640 dev_err(dev, "failed to request %s mem region (0x%zx@0x%llx): %d\n",
641 name, sz, (unsigned long long)*paddr, err);
642 return err;
643 }
644
645 persistent_ram_zap(*prz);
646
647 *paddr += sz;
648
649 return 0;
650}
651
652static int ramoops_parse_dt_size(struct platform_device *pdev,
653 const char *propname, u32 *value)
654{
655 u32 val32 = 0;
656 int ret;
657
658 ret = of_property_read_u32(pdev->dev.of_node, propname, &val32);
659 if (ret < 0 && ret != -EINVAL) {
660 dev_err(&pdev->dev, "failed to parse property %s: %d\n",
661 propname, ret);
662 return ret;
663 }
664
665 if (val32 > INT_MAX) {
666 dev_err(&pdev->dev, "%s %u > INT_MAX\n", propname, val32);
667 return -EOVERFLOW;
668 }
669
670 *value = val32;
671 return 0;
672}
673
674static int ramoops_parse_dt(struct platform_device *pdev,
675 struct ramoops_platform_data *pdata)
676{
677 struct device_node *of_node = pdev->dev.of_node;
678 struct resource *res;
679 u32 value;
680 int ret;
681
682 dev_dbg(&pdev->dev, "using Device Tree\n");
683
684 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
685 if (!res) {
686 dev_err(&pdev->dev,
687 "failed to locate DT /reserved-memory resource\n");
688 return -EINVAL;
689 }
690
691 pdata->mem_size = resource_size(res);
692 pdata->mem_address = res->start;
693 pdata->mem_type = of_property_read_bool(of_node, "unbuffered");
694 pdata->dump_oops = !of_property_read_bool(of_node, "no-dump-oops");
695
696#define parse_size(name, field) { \
697 ret = ramoops_parse_dt_size(pdev, name, &value); \
698 if (ret < 0) \
699 return ret; \
700 field = value; \
701 }
702
703 parse_size("record-size", pdata->record_size);
704 parse_size("console-size", pdata->console_size);
705 parse_size("ftrace-size", pdata->ftrace_size);
706 parse_size("pmsg-size", pdata->pmsg_size);
707 parse_size("ecc-size", pdata->ecc_info.ecc_size);
708 parse_size("flags", pdata->flags);
709
710#undef parse_size
711
712 return 0;
713}
714
715static int ramoops_probe(struct platform_device *pdev)
716{
717 struct device *dev = &pdev->dev;
718 struct ramoops_platform_data *pdata = dev->platform_data;
719 struct ramoops_context *cxt = &oops_cxt;
720 size_t dump_mem_sz;
721 phys_addr_t paddr;
722 int err = -EINVAL;
723
724 if (dev_of_node(dev) && !pdata) {
725 pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
726 if (!pdata) {
727 pr_err("cannot allocate platform data buffer\n");
728 err = -ENOMEM;
729 goto fail_out;
730 }
731
732 err = ramoops_parse_dt(pdev, pdata);
733 if (err < 0)
734 goto fail_out;
735 }
736
737 /*
738 * Only a single ramoops area allowed at a time, so fail extra
739 * probes.
740 */
741 if (cxt->max_dump_cnt) {
742 pr_err("already initialized\n");
743 goto fail_out;
744 }
745
746 /* Make sure we didn't get bogus platform data pointer. */
747 if (!pdata) {
748 pr_err("NULL platform data\n");
749 goto fail_out;
750 }
751
752 if (!pdata->mem_size || (!pdata->record_size && !pdata->console_size &&
753 !pdata->ftrace_size && !pdata->pmsg_size)) {
754 pr_err("The memory size and the record/console size must be "
755 "non-zero\n");
756 goto fail_out;
757 }
758
759 if (pdata->record_size && !is_power_of_2(pdata->record_size))
760 pdata->record_size = rounddown_pow_of_two(pdata->record_size);
761 if (pdata->console_size && !is_power_of_2(pdata->console_size))
762 pdata->console_size = rounddown_pow_of_two(pdata->console_size);
763 if (pdata->ftrace_size && !is_power_of_2(pdata->ftrace_size))
764 pdata->ftrace_size = rounddown_pow_of_two(pdata->ftrace_size);
765 if (pdata->pmsg_size && !is_power_of_2(pdata->pmsg_size))
766 pdata->pmsg_size = rounddown_pow_of_two(pdata->pmsg_size);
767
768 cxt->size = pdata->mem_size;
769 cxt->phys_addr = pdata->mem_address;
770 cxt->memtype = pdata->mem_type;
771 cxt->record_size = pdata->record_size;
772 cxt->console_size = pdata->console_size;
773 cxt->ftrace_size = pdata->ftrace_size;
774 cxt->pmsg_size = pdata->pmsg_size;
775 cxt->dump_oops = pdata->dump_oops;
776 cxt->flags = pdata->flags;
777 cxt->ecc_info = pdata->ecc_info;
778
779 paddr = cxt->phys_addr;
780
781 dump_mem_sz = cxt->size - cxt->console_size - cxt->ftrace_size
782 - cxt->pmsg_size;
783 err = ramoops_init_przs("dump", dev, cxt, &cxt->dprzs, &paddr,
784 dump_mem_sz, cxt->record_size,
785 &cxt->max_dump_cnt, 0, 0);
786 if (err)
787 goto fail_out;
788
789 err = ramoops_init_prz("console", dev, cxt, &cxt->cprz, &paddr,
790 cxt->console_size, 0);
791 if (err)
792 goto fail_init_cprz;
793
794 cxt->max_ftrace_cnt = (cxt->flags & RAMOOPS_FLAG_FTRACE_PER_CPU)
795 ? nr_cpu_ids
796 : 1;
797 err = ramoops_init_przs("ftrace", dev, cxt, &cxt->fprzs, &paddr,
798 cxt->ftrace_size, -1,
799 &cxt->max_ftrace_cnt, LINUX_VERSION_CODE,
800 (cxt->flags & RAMOOPS_FLAG_FTRACE_PER_CPU)
801 ? PRZ_FLAG_NO_LOCK : 0);
802 if (err)
803 goto fail_init_fprz;
804
805 err = ramoops_init_prz("pmsg", dev, cxt, &cxt->mprz, &paddr,
806 cxt->pmsg_size, 0);
807 if (err)
808 goto fail_init_mprz;
809
810 cxt->pstore.data = cxt;
811 /*
812 * Console can handle any buffer size, so prefer LOG_LINE_MAX. If we
813 * have to handle dumps, we must have at least record_size buffer. And
814 * for ftrace, bufsize is irrelevant (if bufsize is 0, buf will be
815 * ZERO_SIZE_PTR).
816 */
817 if (cxt->console_size)
818 cxt->pstore.bufsize = 1024; /* LOG_LINE_MAX */
819 cxt->pstore.bufsize = max(cxt->record_size, cxt->pstore.bufsize);
820 cxt->pstore.buf = kmalloc(cxt->pstore.bufsize, GFP_KERNEL);
821 if (!cxt->pstore.buf) {
822 pr_err("cannot allocate pstore buffer\n");
823 err = -ENOMEM;
824 goto fail_clear;
825 }
826 spin_lock_init(&cxt->pstore.buf_lock);
827
828 cxt->pstore.flags = PSTORE_FLAGS_DMESG;
829 if (cxt->console_size)
830 cxt->pstore.flags |= PSTORE_FLAGS_CONSOLE;
831 if (cxt->ftrace_size)
832 cxt->pstore.flags |= PSTORE_FLAGS_FTRACE;
833 if (cxt->pmsg_size)
834 cxt->pstore.flags |= PSTORE_FLAGS_PMSG;
835
836 err = pstore_register(&cxt->pstore);
837 if (err) {
838 pr_err("registering with pstore failed\n");
839 goto fail_buf;
840 }
841
842 /*
843 * Update the module parameter variables as well so they are visible
844 * through /sys/module/ramoops/parameters/
845 */
846 mem_size = pdata->mem_size;
847 mem_address = pdata->mem_address;
848 record_size = pdata->record_size;
849 dump_oops = pdata->dump_oops;
850 ramoops_console_size = pdata->console_size;
851 ramoops_pmsg_size = pdata->pmsg_size;
852 ramoops_ftrace_size = pdata->ftrace_size;
853
854 pr_info("attached 0x%lx@0x%llx, ecc: %d/%d\n",
855 cxt->size, (unsigned long long)cxt->phys_addr,
856 cxt->ecc_info.ecc_size, cxt->ecc_info.block_size);
857
858 return 0;
859
860fail_buf:
861 kfree(cxt->pstore.buf);
862fail_clear:
863 cxt->pstore.bufsize = 0;
864 persistent_ram_free(cxt->mprz);
865fail_init_mprz:
866fail_init_fprz:
867 persistent_ram_free(cxt->cprz);
868fail_init_cprz:
869 ramoops_free_przs(cxt);
870fail_out:
871 return err;
872}
873
874static int ramoops_remove(struct platform_device *pdev)
875{
876 struct ramoops_context *cxt = &oops_cxt;
877
878 pstore_unregister(&cxt->pstore);
879
880 kfree(cxt->pstore.buf);
881 cxt->pstore.bufsize = 0;
882
883 persistent_ram_free(cxt->mprz);
884 persistent_ram_free(cxt->cprz);
885 ramoops_free_przs(cxt);
886
887 return 0;
888}
889
890static const struct of_device_id dt_match[] = {
891 { .compatible = "ramoops" },
892 {}
893};
894
895static struct platform_driver ramoops_driver = {
896 .probe = ramoops_probe,
897 .remove = ramoops_remove,
898 .driver = {
899 .name = "ramoops",
900 .of_match_table = dt_match,
901 },
902};
903
904static void ramoops_register_dummy(void)
905{
906 if (!mem_size)
907 return;
908
909 pr_info("using module parameters\n");
910
911 dummy_data = kzalloc(sizeof(*dummy_data), GFP_KERNEL);
912 if (!dummy_data) {
913 pr_info("could not allocate pdata\n");
914 return;
915 }
916
917 dummy_data->mem_size = mem_size;
918 dummy_data->mem_address = mem_address;
919 dummy_data->mem_type = mem_type;
920 dummy_data->record_size = record_size;
921 dummy_data->console_size = ramoops_console_size;
922 dummy_data->ftrace_size = ramoops_ftrace_size;
923 dummy_data->pmsg_size = ramoops_pmsg_size;
924 dummy_data->dump_oops = dump_oops;
925 dummy_data->flags = RAMOOPS_FLAG_FTRACE_PER_CPU;
926
927 /*
928 * For backwards compatibility ramoops.ecc=1 means 16 bytes ECC
929 * (using 1 byte for ECC isn't much of use anyway).
930 */
931 dummy_data->ecc_info.ecc_size = ramoops_ecc == 1 ? 16 : ramoops_ecc;
932
933 dummy = platform_device_register_data(NULL, "ramoops", -1,
934 dummy_data, sizeof(struct ramoops_platform_data));
935 if (IS_ERR(dummy)) {
936 pr_info("could not create platform device: %ld\n",
937 PTR_ERR(dummy));
938 }
939}
940
941static int __init ramoops_init(void)
942{
943 ramoops_register_dummy();
944 return platform_driver_register(&ramoops_driver);
945}
946postcore_initcall(ramoops_init);
947
948static void __exit ramoops_exit(void)
949{
950 platform_driver_unregister(&ramoops_driver);
951 platform_device_unregister(dummy);
952 kfree(dummy_data);
953}
954module_exit(ramoops_exit);
955
956MODULE_LICENSE("GPL");
957MODULE_AUTHOR("Marco Stornelli <marco.stornelli@gmail.com>");
958MODULE_DESCRIPTION("RAM Oops/Panic logger/driver");