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