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