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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 char *mem_name;
54module_param_named(mem_name, mem_name, charp, 0400);
55MODULE_PARM_DESC(mem_name, "name of kernel param that holds addr");
56
57static ulong mem_size;
58module_param(mem_size, ulong, 0400);
59MODULE_PARM_DESC(mem_size,
60 "size of reserved RAM used to store oops/panic logs");
61
62static unsigned int mem_type;
63module_param(mem_type, uint, 0400);
64MODULE_PARM_DESC(mem_type,
65 "memory type: 0=write-combined (default), 1=unbuffered, 2=cached");
66
67static int ramoops_max_reason = -1;
68module_param_named(max_reason, ramoops_max_reason, int, 0400);
69MODULE_PARM_DESC(max_reason,
70 "maximum reason for kmsg dump (default 2: Oops and Panic) ");
71
72static int ramoops_ecc;
73module_param_named(ecc, ramoops_ecc, int, 0400);
74MODULE_PARM_DESC(ramoops_ecc,
75 "if non-zero, the option enables ECC support and specifies "
76 "ECC buffer size in bytes (1 is a special value, means 16 "
77 "bytes ECC)");
78
79static int ramoops_dump_oops = -1;
80module_param_named(dump_oops, ramoops_dump_oops, int, 0400);
81MODULE_PARM_DESC(dump_oops,
82 "(deprecated: use max_reason instead) set to 1 to dump oopses & panics, 0 to only dump panics");
83
84struct ramoops_context {
85 struct persistent_ram_zone **dprzs; /* Oops dump zones */
86 struct persistent_ram_zone *cprz; /* Console zone */
87 struct persistent_ram_zone **fprzs; /* Ftrace zones */
88 struct persistent_ram_zone *mprz; /* PMSG zone */
89 phys_addr_t phys_addr;
90 unsigned long size;
91 unsigned int memtype;
92 size_t record_size;
93 size_t console_size;
94 size_t ftrace_size;
95 size_t pmsg_size;
96 u32 flags;
97 struct persistent_ram_ecc_info ecc_info;
98 unsigned int max_dump_cnt;
99 unsigned int dump_write_cnt;
100 /* _read_cnt need clear on ramoops_pstore_open */
101 unsigned int dump_read_cnt;
102 unsigned int console_read_cnt;
103 unsigned int max_ftrace_cnt;
104 unsigned int ftrace_read_cnt;
105 unsigned int pmsg_read_cnt;
106 struct pstore_info pstore;
107};
108
109static struct platform_device *dummy;
110
111static int ramoops_pstore_open(struct pstore_info *psi)
112{
113 struct ramoops_context *cxt = psi->data;
114
115 cxt->dump_read_cnt = 0;
116 cxt->console_read_cnt = 0;
117 cxt->ftrace_read_cnt = 0;
118 cxt->pmsg_read_cnt = 0;
119 return 0;
120}
121
122static struct persistent_ram_zone *
123ramoops_get_next_prz(struct persistent_ram_zone *przs[], int id,
124 struct pstore_record *record)
125{
126 struct persistent_ram_zone *prz;
127
128 /* Give up if we never existed or have hit the end. */
129 if (!przs)
130 return NULL;
131
132 prz = przs[id];
133 if (!prz)
134 return NULL;
135
136 /* Update old/shadowed buffer. */
137 if (prz->type == PSTORE_TYPE_DMESG)
138 persistent_ram_save_old(prz);
139
140 if (!persistent_ram_old_size(prz))
141 return NULL;
142
143 record->type = prz->type;
144 record->id = id;
145
146 return prz;
147}
148
149static int ramoops_read_kmsg_hdr(char *buffer, struct timespec64 *time,
150 bool *compressed)
151{
152 char data_type;
153 int header_length = 0;
154
155 if (sscanf(buffer, RAMOOPS_KERNMSG_HDR "%lld.%lu-%c\n%n",
156 (time64_t *)&time->tv_sec, &time->tv_nsec, &data_type,
157 &header_length) == 3) {
158 time->tv_nsec *= 1000;
159 if (data_type == 'C')
160 *compressed = true;
161 else
162 *compressed = false;
163 } else if (sscanf(buffer, RAMOOPS_KERNMSG_HDR "%lld.%lu\n%n",
164 (time64_t *)&time->tv_sec, &time->tv_nsec,
165 &header_length) == 2) {
166 time->tv_nsec *= 1000;
167 *compressed = false;
168 } else {
169 time->tv_sec = 0;
170 time->tv_nsec = 0;
171 *compressed = false;
172 }
173 return header_length;
174}
175
176static bool prz_ok(struct persistent_ram_zone *prz)
177{
178 return !!prz && !!(persistent_ram_old_size(prz) +
179 persistent_ram_ecc_string(prz, NULL, 0));
180}
181
182static ssize_t ramoops_pstore_read(struct pstore_record *record)
183{
184 ssize_t size = 0;
185 struct ramoops_context *cxt = record->psi->data;
186 struct persistent_ram_zone *prz = NULL;
187 int header_length = 0;
188 bool free_prz = false;
189
190 /*
191 * Ramoops headers provide time stamps for PSTORE_TYPE_DMESG, but
192 * PSTORE_TYPE_CONSOLE and PSTORE_TYPE_FTRACE don't currently have
193 * valid time stamps, so it is initialized to zero.
194 */
195 record->time.tv_sec = 0;
196 record->time.tv_nsec = 0;
197 record->compressed = false;
198
199 /* Find the next valid persistent_ram_zone for DMESG */
200 while (cxt->dump_read_cnt < cxt->max_dump_cnt && !prz) {
201 prz = ramoops_get_next_prz(cxt->dprzs, cxt->dump_read_cnt++,
202 record);
203 if (!prz_ok(prz))
204 continue;
205 header_length = ramoops_read_kmsg_hdr(persistent_ram_old(prz),
206 &record->time,
207 &record->compressed);
208 /* Clear and skip this DMESG record if it has no valid header */
209 if (!header_length) {
210 persistent_ram_free_old(prz);
211 persistent_ram_zap(prz);
212 prz = NULL;
213 }
214 }
215
216 if (!prz_ok(prz) && !cxt->console_read_cnt++)
217 prz = ramoops_get_next_prz(&cxt->cprz, 0 /* single */, record);
218
219 if (!prz_ok(prz) && !cxt->pmsg_read_cnt++)
220 prz = ramoops_get_next_prz(&cxt->mprz, 0 /* single */, record);
221
222 /* ftrace is last since it may want to dynamically allocate memory. */
223 if (!prz_ok(prz)) {
224 if (!(cxt->flags & RAMOOPS_FLAG_FTRACE_PER_CPU) &&
225 !cxt->ftrace_read_cnt++) {
226 prz = ramoops_get_next_prz(cxt->fprzs, 0 /* single */,
227 record);
228 } else {
229 /*
230 * Build a new dummy record which combines all the
231 * per-cpu records including metadata and ecc info.
232 */
233 struct persistent_ram_zone *tmp_prz, *prz_next;
234
235 tmp_prz = kzalloc(sizeof(struct persistent_ram_zone),
236 GFP_KERNEL);
237 if (!tmp_prz)
238 return -ENOMEM;
239 prz = tmp_prz;
240 free_prz = true;
241
242 while (cxt->ftrace_read_cnt < cxt->max_ftrace_cnt) {
243 prz_next = ramoops_get_next_prz(cxt->fprzs,
244 cxt->ftrace_read_cnt++, record);
245
246 if (!prz_ok(prz_next))
247 continue;
248
249 tmp_prz->ecc_info = prz_next->ecc_info;
250 tmp_prz->corrected_bytes +=
251 prz_next->corrected_bytes;
252 tmp_prz->bad_blocks += prz_next->bad_blocks;
253
254 size = pstore_ftrace_combine_log(
255 &tmp_prz->old_log,
256 &tmp_prz->old_log_size,
257 prz_next->old_log,
258 prz_next->old_log_size);
259 if (size)
260 goto out;
261 }
262 record->id = 0;
263 }
264 }
265
266 if (!prz_ok(prz)) {
267 size = 0;
268 goto out;
269 }
270
271 size = persistent_ram_old_size(prz) - header_length;
272
273 /* ECC correction notice */
274 record->ecc_notice_size = persistent_ram_ecc_string(prz, NULL, 0);
275
276 record->buf = kvzalloc(size + record->ecc_notice_size + 1, GFP_KERNEL);
277 if (record->buf == NULL) {
278 size = -ENOMEM;
279 goto out;
280 }
281
282 memcpy(record->buf, (char *)persistent_ram_old(prz) + header_length,
283 size);
284
285 persistent_ram_ecc_string(prz, record->buf + size,
286 record->ecc_notice_size + 1);
287
288out:
289 if (free_prz) {
290 kvfree(prz->old_log);
291 kfree(prz);
292 }
293
294 return size;
295}
296
297static size_t ramoops_write_kmsg_hdr(struct persistent_ram_zone *prz,
298 struct pstore_record *record)
299{
300 char hdr[36]; /* "===="(4), %lld(20), "."(1), %06lu(6), "-%c\n"(3) */
301 size_t len;
302
303 len = scnprintf(hdr, sizeof(hdr),
304 RAMOOPS_KERNMSG_HDR "%lld.%06lu-%c\n",
305 (time64_t)record->time.tv_sec,
306 record->time.tv_nsec / 1000,
307 record->compressed ? 'C' : 'D');
308 persistent_ram_write(prz, hdr, len);
309
310 return len;
311}
312
313static int notrace ramoops_pstore_write(struct pstore_record *record)
314{
315 struct ramoops_context *cxt = record->psi->data;
316 struct persistent_ram_zone *prz;
317 size_t size, hlen;
318
319 if (record->type == PSTORE_TYPE_CONSOLE) {
320 if (!cxt->cprz)
321 return -ENOMEM;
322 persistent_ram_write(cxt->cprz, record->buf, record->size);
323 return 0;
324 } else if (record->type == PSTORE_TYPE_FTRACE) {
325 int zonenum;
326
327 if (!cxt->fprzs)
328 return -ENOMEM;
329 /*
330 * Choose zone by if we're using per-cpu buffers.
331 */
332 if (cxt->flags & RAMOOPS_FLAG_FTRACE_PER_CPU)
333 zonenum = smp_processor_id();
334 else
335 zonenum = 0;
336
337 persistent_ram_write(cxt->fprzs[zonenum], record->buf,
338 record->size);
339 return 0;
340 } else if (record->type == PSTORE_TYPE_PMSG) {
341 pr_warn_ratelimited("PMSG shouldn't call %s\n", __func__);
342 return -EINVAL;
343 }
344
345 if (record->type != PSTORE_TYPE_DMESG)
346 return -EINVAL;
347
348 /*
349 * We could filter on record->reason here if we wanted to (which
350 * would duplicate what happened before the "max_reason" setting
351 * was added), but that would defeat the purpose of a system
352 * changing printk.always_kmsg_dump, so instead log everything that
353 * the kmsg dumper sends us, since it should be doing the filtering
354 * based on the combination of printk.always_kmsg_dump and our
355 * requested "max_reason".
356 */
357
358 /*
359 * Explicitly only take the first part of any new crash.
360 * If our buffer is larger than kmsg_bytes, this can never happen,
361 * and if our buffer is smaller than kmsg_bytes, we don't want the
362 * report split across multiple records.
363 */
364 if (record->part != 1)
365 return -ENOSPC;
366
367 if (!cxt->dprzs)
368 return -ENOSPC;
369
370 prz = cxt->dprzs[cxt->dump_write_cnt];
371
372 /*
373 * Since this is a new crash dump, we need to reset the buffer in
374 * case it still has an old dump present. Without this, the new dump
375 * will get appended, which would seriously confuse anything trying
376 * to check dump file contents. Specifically, ramoops_read_kmsg_hdr()
377 * expects to find a dump header in the beginning of buffer data, so
378 * we must to reset the buffer values, in order to ensure that the
379 * header will be written to the beginning of the buffer.
380 */
381 persistent_ram_zap(prz);
382
383 /* Build header and append record contents. */
384 hlen = ramoops_write_kmsg_hdr(prz, record);
385 if (!hlen)
386 return -ENOMEM;
387
388 size = record->size;
389 if (size + hlen > prz->buffer_size)
390 size = prz->buffer_size - hlen;
391 persistent_ram_write(prz, record->buf, size);
392
393 cxt->dump_write_cnt = (cxt->dump_write_cnt + 1) % cxt->max_dump_cnt;
394
395 return 0;
396}
397
398static int notrace ramoops_pstore_write_user(struct pstore_record *record,
399 const char __user *buf)
400{
401 if (record->type == PSTORE_TYPE_PMSG) {
402 struct ramoops_context *cxt = record->psi->data;
403
404 if (!cxt->mprz)
405 return -ENOMEM;
406 return persistent_ram_write_user(cxt->mprz, buf, record->size);
407 }
408
409 return -EINVAL;
410}
411
412static int ramoops_pstore_erase(struct pstore_record *record)
413{
414 struct ramoops_context *cxt = record->psi->data;
415 struct persistent_ram_zone *prz;
416
417 switch (record->type) {
418 case PSTORE_TYPE_DMESG:
419 if (record->id >= cxt->max_dump_cnt)
420 return -EINVAL;
421 prz = cxt->dprzs[record->id];
422 break;
423 case PSTORE_TYPE_CONSOLE:
424 prz = cxt->cprz;
425 break;
426 case PSTORE_TYPE_FTRACE:
427 if (record->id >= cxt->max_ftrace_cnt)
428 return -EINVAL;
429 prz = cxt->fprzs[record->id];
430 break;
431 case PSTORE_TYPE_PMSG:
432 prz = cxt->mprz;
433 break;
434 default:
435 return -EINVAL;
436 }
437
438 persistent_ram_free_old(prz);
439 persistent_ram_zap(prz);
440
441 return 0;
442}
443
444static struct ramoops_context oops_cxt = {
445 .pstore = {
446 .owner = THIS_MODULE,
447 .name = "ramoops",
448 .open = ramoops_pstore_open,
449 .read = ramoops_pstore_read,
450 .write = ramoops_pstore_write,
451 .write_user = ramoops_pstore_write_user,
452 .erase = ramoops_pstore_erase,
453 },
454};
455
456static void ramoops_free_przs(struct ramoops_context *cxt)
457{
458 int i;
459
460 /* Free pmsg PRZ */
461 persistent_ram_free(&cxt->mprz);
462
463 /* Free console PRZ */
464 persistent_ram_free(&cxt->cprz);
465
466 /* Free dump PRZs */
467 if (cxt->dprzs) {
468 for (i = 0; i < cxt->max_dump_cnt; i++)
469 persistent_ram_free(&cxt->dprzs[i]);
470
471 kfree(cxt->dprzs);
472 cxt->dprzs = NULL;
473 cxt->max_dump_cnt = 0;
474 }
475
476 /* Free ftrace PRZs */
477 if (cxt->fprzs) {
478 for (i = 0; i < cxt->max_ftrace_cnt; i++)
479 persistent_ram_free(&cxt->fprzs[i]);
480 kfree(cxt->fprzs);
481 cxt->fprzs = NULL;
482 cxt->max_ftrace_cnt = 0;
483 }
484}
485
486static int ramoops_init_przs(const char *name,
487 struct device *dev, struct ramoops_context *cxt,
488 struct persistent_ram_zone ***przs,
489 phys_addr_t *paddr, size_t mem_sz,
490 ssize_t record_size,
491 unsigned int *cnt, u32 sig, u32 flags)
492{
493 int err = -ENOMEM;
494 int i;
495 size_t zone_sz;
496 struct persistent_ram_zone **prz_ar;
497
498 /* Allocate nothing for 0 mem_sz or 0 record_size. */
499 if (mem_sz == 0 || record_size == 0) {
500 *cnt = 0;
501 return 0;
502 }
503
504 /*
505 * If we have a negative record size, calculate it based on
506 * mem_sz / *cnt. If we have a positive record size, calculate
507 * cnt from mem_sz / record_size.
508 */
509 if (record_size < 0) {
510 if (*cnt == 0)
511 return 0;
512 record_size = mem_sz / *cnt;
513 if (record_size == 0) {
514 dev_err(dev, "%s record size == 0 (%zu / %u)\n",
515 name, mem_sz, *cnt);
516 goto fail;
517 }
518 } else {
519 *cnt = mem_sz / record_size;
520 if (*cnt == 0) {
521 dev_err(dev, "%s record count == 0 (%zu / %zu)\n",
522 name, mem_sz, record_size);
523 goto fail;
524 }
525 }
526
527 if (*paddr + mem_sz - cxt->phys_addr > cxt->size) {
528 dev_err(dev, "no room for %s mem region (0x%zx@0x%llx) in (0x%lx@0x%llx)\n",
529 name,
530 mem_sz, (unsigned long long)*paddr,
531 cxt->size, (unsigned long long)cxt->phys_addr);
532 goto fail;
533 }
534
535 zone_sz = mem_sz / *cnt;
536 zone_sz = ALIGN_DOWN(zone_sz, 2);
537 if (!zone_sz) {
538 dev_err(dev, "%s zone size == 0\n", name);
539 goto fail;
540 }
541
542 prz_ar = kcalloc(*cnt, sizeof(**przs), GFP_KERNEL);
543 if (!prz_ar)
544 goto fail;
545
546 for (i = 0; i < *cnt; i++) {
547 char *label;
548
549 if (*cnt == 1)
550 label = kasprintf(GFP_KERNEL, "ramoops:%s", name);
551 else
552 label = kasprintf(GFP_KERNEL, "ramoops:%s(%d/%d)",
553 name, i, *cnt - 1);
554 prz_ar[i] = persistent_ram_new(*paddr, zone_sz, sig,
555 &cxt->ecc_info,
556 cxt->memtype, flags, label);
557 kfree(label);
558 if (IS_ERR(prz_ar[i])) {
559 err = PTR_ERR(prz_ar[i]);
560 dev_err(dev, "failed to request %s mem region (0x%zx@0x%llx): %d\n",
561 name, record_size,
562 (unsigned long long)*paddr, err);
563
564 while (i > 0) {
565 i--;
566 persistent_ram_free(&prz_ar[i]);
567 }
568 kfree(prz_ar);
569 prz_ar = NULL;
570 goto fail;
571 }
572 *paddr += zone_sz;
573 prz_ar[i]->type = pstore_name_to_type(name);
574 }
575
576 *przs = prz_ar;
577 return 0;
578
579fail:
580 *cnt = 0;
581 return err;
582}
583
584static int ramoops_init_prz(const char *name,
585 struct device *dev, struct ramoops_context *cxt,
586 struct persistent_ram_zone **prz,
587 phys_addr_t *paddr, size_t sz, u32 sig)
588{
589 char *label;
590
591 if (!sz)
592 return 0;
593
594 if (*paddr + sz - cxt->phys_addr > cxt->size) {
595 dev_err(dev, "no room for %s mem region (0x%zx@0x%llx) in (0x%lx@0x%llx)\n",
596 name, sz, (unsigned long long)*paddr,
597 cxt->size, (unsigned long long)cxt->phys_addr);
598 return -ENOMEM;
599 }
600
601 label = kasprintf(GFP_KERNEL, "ramoops:%s", name);
602 *prz = persistent_ram_new(*paddr, sz, sig, &cxt->ecc_info,
603 cxt->memtype, PRZ_FLAG_ZAP_OLD, label);
604 kfree(label);
605 if (IS_ERR(*prz)) {
606 int err = PTR_ERR(*prz);
607
608 dev_err(dev, "failed to request %s mem region (0x%zx@0x%llx): %d\n",
609 name, sz, (unsigned long long)*paddr, err);
610 return err;
611 }
612
613 *paddr += sz;
614 (*prz)->type = pstore_name_to_type(name);
615
616 return 0;
617}
618
619/* Read a u32 from a dt property and make sure it's safe for an int. */
620static int ramoops_parse_dt_u32(struct platform_device *pdev,
621 const char *propname,
622 u32 default_value, u32 *value)
623{
624 u32 val32 = 0;
625 int ret;
626
627 ret = of_property_read_u32(pdev->dev.of_node, propname, &val32);
628 if (ret == -EINVAL) {
629 /* field is missing, use default value. */
630 val32 = default_value;
631 } else if (ret < 0) {
632 dev_err(&pdev->dev, "failed to parse property %s: %d\n",
633 propname, ret);
634 return ret;
635 }
636
637 /* Sanity check our results. */
638 if (val32 > INT_MAX) {
639 dev_err(&pdev->dev, "%s %u > INT_MAX\n", propname, val32);
640 return -EOVERFLOW;
641 }
642
643 *value = val32;
644 return 0;
645}
646
647static int ramoops_parse_dt(struct platform_device *pdev,
648 struct ramoops_platform_data *pdata)
649{
650 struct device_node *of_node = pdev->dev.of_node;
651 struct device_node *parent_node;
652 struct resource *res;
653 u32 value;
654 int ret;
655
656 dev_dbg(&pdev->dev, "using Device Tree\n");
657
658 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
659 if (!res) {
660 dev_err(&pdev->dev,
661 "failed to locate DT /reserved-memory resource\n");
662 return -EINVAL;
663 }
664
665 pdata->mem_size = resource_size(res);
666 pdata->mem_address = res->start;
667 /*
668 * Setting "unbuffered" is deprecated and will be ignored if
669 * "mem_type" is also specified.
670 */
671 pdata->mem_type = of_property_read_bool(of_node, "unbuffered");
672 /*
673 * Setting "no-dump-oops" is deprecated and will be ignored if
674 * "max_reason" is also specified.
675 */
676 if (of_property_read_bool(of_node, "no-dump-oops"))
677 pdata->max_reason = KMSG_DUMP_PANIC;
678 else
679 pdata->max_reason = KMSG_DUMP_OOPS;
680
681#define parse_u32(name, field, default_value) { \
682 ret = ramoops_parse_dt_u32(pdev, name, default_value, \
683 &value); \
684 if (ret < 0) \
685 return ret; \
686 field = value; \
687 }
688
689 parse_u32("mem-type", pdata->mem_type, pdata->mem_type);
690 parse_u32("record-size", pdata->record_size, 0);
691 parse_u32("console-size", pdata->console_size, 0);
692 parse_u32("ftrace-size", pdata->ftrace_size, 0);
693 parse_u32("pmsg-size", pdata->pmsg_size, 0);
694 parse_u32("ecc-size", pdata->ecc_info.ecc_size, 0);
695 parse_u32("flags", pdata->flags, 0);
696 parse_u32("max-reason", pdata->max_reason, pdata->max_reason);
697
698#undef parse_u32
699
700 /*
701 * Some old Chromebooks relied on the kernel setting the
702 * console_size and pmsg_size to the record size since that's
703 * what the downstream kernel did. These same Chromebooks had
704 * "ramoops" straight under the root node which isn't
705 * according to the current upstream bindings (though it was
706 * arguably acceptable under a prior version of the bindings).
707 * Let's make those old Chromebooks work by detecting that
708 * we're not a child of "reserved-memory" and mimicking the
709 * expected behavior.
710 */
711 parent_node = of_get_parent(of_node);
712 if (!of_node_name_eq(parent_node, "reserved-memory") &&
713 !pdata->console_size && !pdata->ftrace_size &&
714 !pdata->pmsg_size && !pdata->ecc_info.ecc_size) {
715 pdata->console_size = pdata->record_size;
716 pdata->pmsg_size = pdata->record_size;
717 }
718 of_node_put(parent_node);
719
720 return 0;
721}
722
723static int ramoops_probe(struct platform_device *pdev)
724{
725 struct device *dev = &pdev->dev;
726 struct ramoops_platform_data *pdata = dev->platform_data;
727 struct ramoops_platform_data pdata_local;
728 struct ramoops_context *cxt = &oops_cxt;
729 size_t dump_mem_sz;
730 phys_addr_t paddr;
731 int err = -EINVAL;
732
733 /*
734 * Only a single ramoops area allowed at a time, so fail extra
735 * probes.
736 */
737 if (cxt->max_dump_cnt) {
738 pr_err("already initialized\n");
739 goto fail_out;
740 }
741
742 if (dev_of_node(dev) && !pdata) {
743 pdata = &pdata_local;
744 memset(pdata, 0, sizeof(*pdata));
745
746 err = ramoops_parse_dt(pdev, pdata);
747 if (err < 0)
748 goto fail_out;
749 }
750
751 /* Make sure we didn't get bogus platform data pointer. */
752 if (!pdata) {
753 pr_err("NULL platform data\n");
754 err = -EINVAL;
755 goto fail_out;
756 }
757
758 if (!pdata->mem_size || (!pdata->record_size && !pdata->console_size &&
759 !pdata->ftrace_size && !pdata->pmsg_size)) {
760 pr_err("The memory size and the record/console size must be "
761 "non-zero\n");
762 err = -EINVAL;
763 goto fail_out;
764 }
765
766 if (pdata->record_size && !is_power_of_2(pdata->record_size))
767 pdata->record_size = rounddown_pow_of_two(pdata->record_size);
768 if (pdata->console_size && !is_power_of_2(pdata->console_size))
769 pdata->console_size = rounddown_pow_of_two(pdata->console_size);
770 if (pdata->ftrace_size && !is_power_of_2(pdata->ftrace_size))
771 pdata->ftrace_size = rounddown_pow_of_two(pdata->ftrace_size);
772 if (pdata->pmsg_size && !is_power_of_2(pdata->pmsg_size))
773 pdata->pmsg_size = rounddown_pow_of_two(pdata->pmsg_size);
774
775 cxt->size = pdata->mem_size;
776 cxt->phys_addr = pdata->mem_address;
777 cxt->memtype = pdata->mem_type;
778 cxt->record_size = pdata->record_size;
779 cxt->console_size = pdata->console_size;
780 cxt->ftrace_size = pdata->ftrace_size;
781 cxt->pmsg_size = pdata->pmsg_size;
782 cxt->flags = pdata->flags;
783 cxt->ecc_info = pdata->ecc_info;
784
785 paddr = cxt->phys_addr;
786
787 dump_mem_sz = cxt->size - cxt->console_size - cxt->ftrace_size
788 - cxt->pmsg_size;
789 err = ramoops_init_przs("dmesg", dev, cxt, &cxt->dprzs, &paddr,
790 dump_mem_sz, cxt->record_size,
791 &cxt->max_dump_cnt, 0, 0);
792 if (err)
793 goto fail_init;
794
795 err = ramoops_init_prz("console", dev, cxt, &cxt->cprz, &paddr,
796 cxt->console_size, 0);
797 if (err)
798 goto fail_init;
799
800 err = ramoops_init_prz("pmsg", dev, cxt, &cxt->mprz, &paddr,
801 cxt->pmsg_size, 0);
802 if (err)
803 goto fail_init;
804
805 cxt->max_ftrace_cnt = (cxt->flags & RAMOOPS_FLAG_FTRACE_PER_CPU)
806 ? nr_cpu_ids
807 : 1;
808 err = ramoops_init_przs("ftrace", dev, cxt, &cxt->fprzs, &paddr,
809 cxt->ftrace_size, -1,
810 &cxt->max_ftrace_cnt, LINUX_VERSION_CODE,
811 (cxt->flags & RAMOOPS_FLAG_FTRACE_PER_CPU)
812 ? PRZ_FLAG_NO_LOCK : 0);
813 if (err)
814 goto fail_init;
815
816 cxt->pstore.data = cxt;
817 /*
818 * Prepare frontend flags based on which areas are initialized.
819 * For ramoops_init_przs() cases, the "max count" variable tells
820 * if there are regions present. For ramoops_init_prz() cases,
821 * the single region size is how to check.
822 */
823 cxt->pstore.flags = 0;
824 if (cxt->max_dump_cnt) {
825 cxt->pstore.flags |= PSTORE_FLAGS_DMESG;
826 cxt->pstore.max_reason = pdata->max_reason;
827 }
828 if (cxt->console_size)
829 cxt->pstore.flags |= PSTORE_FLAGS_CONSOLE;
830 if (cxt->max_ftrace_cnt)
831 cxt->pstore.flags |= PSTORE_FLAGS_FTRACE;
832 if (cxt->pmsg_size)
833 cxt->pstore.flags |= PSTORE_FLAGS_PMSG;
834
835 /*
836 * Since bufsize is only used for dmesg crash dumps, it
837 * must match the size of the dprz record (after PRZ header
838 * and ECC bytes have been accounted for).
839 */
840 if (cxt->pstore.flags & PSTORE_FLAGS_DMESG) {
841 cxt->pstore.bufsize = cxt->dprzs[0]->buffer_size;
842 cxt->pstore.buf = kvzalloc(cxt->pstore.bufsize, GFP_KERNEL);
843 if (!cxt->pstore.buf) {
844 pr_err("cannot allocate pstore crash dump buffer\n");
845 err = -ENOMEM;
846 goto fail_clear;
847 }
848 }
849
850 err = pstore_register(&cxt->pstore);
851 if (err) {
852 pr_err("registering with pstore failed\n");
853 goto fail_buf;
854 }
855
856 /*
857 * Update the module parameter variables as well so they are visible
858 * through /sys/module/ramoops/parameters/
859 */
860 mem_size = pdata->mem_size;
861 mem_address = pdata->mem_address;
862 record_size = pdata->record_size;
863 ramoops_max_reason = pdata->max_reason;
864 ramoops_console_size = pdata->console_size;
865 ramoops_pmsg_size = pdata->pmsg_size;
866 ramoops_ftrace_size = pdata->ftrace_size;
867
868 pr_info("using 0x%lx@0x%llx, ecc: %d\n",
869 cxt->size, (unsigned long long)cxt->phys_addr,
870 cxt->ecc_info.ecc_size);
871
872 return 0;
873
874fail_buf:
875 kvfree(cxt->pstore.buf);
876fail_clear:
877 cxt->pstore.bufsize = 0;
878fail_init:
879 ramoops_free_przs(cxt);
880fail_out:
881 return err;
882}
883
884static void ramoops_remove(struct platform_device *pdev)
885{
886 struct ramoops_context *cxt = &oops_cxt;
887
888 pstore_unregister(&cxt->pstore);
889
890 kvfree(cxt->pstore.buf);
891 cxt->pstore.bufsize = 0;
892
893 ramoops_free_przs(cxt);
894}
895
896static const struct of_device_id dt_match[] = {
897 { .compatible = "ramoops" },
898 {}
899};
900MODULE_DEVICE_TABLE(of, dt_match);
901
902static struct platform_driver ramoops_driver = {
903 .probe = ramoops_probe,
904 .remove = ramoops_remove,
905 .driver = {
906 .name = "ramoops",
907 .of_match_table = dt_match,
908 },
909};
910
911static inline void ramoops_unregister_dummy(void)
912{
913 platform_device_unregister(dummy);
914 dummy = NULL;
915}
916
917static void __init ramoops_register_dummy(void)
918{
919 struct ramoops_platform_data pdata;
920
921 if (mem_name) {
922 phys_addr_t start;
923 phys_addr_t size;
924
925 if (reserve_mem_find_by_name(mem_name, &start, &size)) {
926 mem_address = start;
927 mem_size = size;
928 }
929 }
930
931 /*
932 * Prepare a dummy platform data structure to carry the module
933 * parameters. If mem_size isn't set, then there are no module
934 * parameters, and we can skip this.
935 */
936 if (!mem_size)
937 return;
938
939 pr_info("using module parameters\n");
940
941 memset(&pdata, 0, sizeof(pdata));
942 pdata.mem_size = mem_size;
943 pdata.mem_address = mem_address;
944 pdata.mem_type = mem_type;
945 pdata.record_size = record_size;
946 pdata.console_size = ramoops_console_size;
947 pdata.ftrace_size = ramoops_ftrace_size;
948 pdata.pmsg_size = ramoops_pmsg_size;
949 /* If "max_reason" is set, its value has priority over "dump_oops". */
950 if (ramoops_max_reason >= 0)
951 pdata.max_reason = ramoops_max_reason;
952 /* Otherwise, if "dump_oops" is set, parse it into "max_reason". */
953 else if (ramoops_dump_oops != -1)
954 pdata.max_reason = ramoops_dump_oops ? KMSG_DUMP_OOPS
955 : KMSG_DUMP_PANIC;
956 /* And if neither are explicitly set, use the default. */
957 else
958 pdata.max_reason = KMSG_DUMP_OOPS;
959 pdata.flags = RAMOOPS_FLAG_FTRACE_PER_CPU;
960
961 /*
962 * For backwards compatibility ramoops.ecc=1 means 16 bytes ECC
963 * (using 1 byte for ECC isn't much of use anyway).
964 */
965 pdata.ecc_info.ecc_size = ramoops_ecc == 1 ? 16 : ramoops_ecc;
966
967 dummy = platform_device_register_data(NULL, "ramoops", -1,
968 &pdata, sizeof(pdata));
969 if (IS_ERR(dummy)) {
970 pr_info("could not create platform device: %ld\n",
971 PTR_ERR(dummy));
972 dummy = NULL;
973 }
974}
975
976static int __init ramoops_init(void)
977{
978 int ret;
979
980 ramoops_register_dummy();
981 ret = platform_driver_register(&ramoops_driver);
982 if (ret != 0)
983 ramoops_unregister_dummy();
984
985 return ret;
986}
987postcore_initcall(ramoops_init);
988
989static void __exit ramoops_exit(void)
990{
991 platform_driver_unregister(&ramoops_driver);
992 ramoops_unregister_dummy();
993}
994module_exit(ramoops_exit);
995
996MODULE_LICENSE("GPL");
997MODULE_AUTHOR("Marco Stornelli <marco.stornelli@gmail.com>");
998MODULE_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/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};
896MODULE_DEVICE_TABLE(of, dt_match);
897
898static struct platform_driver ramoops_driver = {
899 .probe = ramoops_probe,
900 .remove_new = ramoops_remove,
901 .driver = {
902 .name = "ramoops",
903 .of_match_table = dt_match,
904 },
905};
906
907static inline void ramoops_unregister_dummy(void)
908{
909 platform_device_unregister(dummy);
910 dummy = NULL;
911}
912
913static void __init ramoops_register_dummy(void)
914{
915 struct ramoops_platform_data pdata;
916
917 /*
918 * Prepare a dummy platform data structure to carry the module
919 * parameters. If mem_size isn't set, then there are no module
920 * parameters, and we can skip this.
921 */
922 if (!mem_size)
923 return;
924
925 pr_info("using module parameters\n");
926
927 memset(&pdata, 0, sizeof(pdata));
928 pdata.mem_size = mem_size;
929 pdata.mem_address = mem_address;
930 pdata.mem_type = mem_type;
931 pdata.record_size = record_size;
932 pdata.console_size = ramoops_console_size;
933 pdata.ftrace_size = ramoops_ftrace_size;
934 pdata.pmsg_size = ramoops_pmsg_size;
935 /* If "max_reason" is set, its value has priority over "dump_oops". */
936 if (ramoops_max_reason >= 0)
937 pdata.max_reason = ramoops_max_reason;
938 /* Otherwise, if "dump_oops" is set, parse it into "max_reason". */
939 else if (ramoops_dump_oops != -1)
940 pdata.max_reason = ramoops_dump_oops ? KMSG_DUMP_OOPS
941 : KMSG_DUMP_PANIC;
942 /* And if neither are explicitly set, use the default. */
943 else
944 pdata.max_reason = KMSG_DUMP_OOPS;
945 pdata.flags = RAMOOPS_FLAG_FTRACE_PER_CPU;
946
947 /*
948 * For backwards compatibility ramoops.ecc=1 means 16 bytes ECC
949 * (using 1 byte for ECC isn't much of use anyway).
950 */
951 pdata.ecc_info.ecc_size = ramoops_ecc == 1 ? 16 : ramoops_ecc;
952
953 dummy = platform_device_register_data(NULL, "ramoops", -1,
954 &pdata, sizeof(pdata));
955 if (IS_ERR(dummy)) {
956 pr_info("could not create platform device: %ld\n",
957 PTR_ERR(dummy));
958 dummy = NULL;
959 }
960}
961
962static int __init ramoops_init(void)
963{
964 int ret;
965
966 ramoops_register_dummy();
967 ret = platform_driver_register(&ramoops_driver);
968 if (ret != 0)
969 ramoops_unregister_dummy();
970
971 return ret;
972}
973postcore_initcall(ramoops_init);
974
975static void __exit ramoops_exit(void)
976{
977 platform_driver_unregister(&ramoops_driver);
978 ramoops_unregister_dummy();
979}
980module_exit(ramoops_exit);
981
982MODULE_LICENSE("GPL");
983MODULE_AUTHOR("Marco Stornelli <marco.stornelli@gmail.com>");
984MODULE_DESCRIPTION("RAM Oops/Panic logger/driver");