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