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