1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * RAM Oops/Panic logger
4 *
5 * Copyright (C) 2010 Marco Stornelli <marco.stornelli@gmail.com>
6 * Copyright (C) 2011 Kees Cook <keescook@chromium.org>
7 */
8
9 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
10
11 #include <linux/kernel.h>
12 #include <linux/err.h>
13 #include <linux/module.h>
14 #include <linux/version.h>
15 #include <linux/pstore.h>
16 #include <linux/io.h>
17 #include <linux/ioport.h>
18 #include <linux/platform_device.h>
19 #include <linux/slab.h>
20 #include <linux/compiler.h>
21 #include <linux/of.h>
22 #include <linux/of_address.h>
23 #include <linux/mm.h>
24
25 #include "internal.h"
26 #include "ram_internal.h"
27
28 #define RAMOOPS_KERNMSG_HDR "===="
29 #define MIN_MEM_SIZE 4096UL
30
31 static ulong record_size = MIN_MEM_SIZE;
32 module_param(record_size, ulong, 0400);
33 MODULE_PARM_DESC(record_size,
34 "size of each dump done on oops/panic");
35
36 static ulong ramoops_console_size = MIN_MEM_SIZE;
37 module_param_named(console_size, ramoops_console_size, ulong, 0400);
38 MODULE_PARM_DESC(console_size, "size of kernel console log");
39
40 static ulong ramoops_ftrace_size = MIN_MEM_SIZE;
41 module_param_named(ftrace_size, ramoops_ftrace_size, ulong, 0400);
42 MODULE_PARM_DESC(ftrace_size, "size of ftrace log");
43
44 static ulong ramoops_pmsg_size = MIN_MEM_SIZE;
45 module_param_named(pmsg_size, ramoops_pmsg_size, ulong, 0400);
46 MODULE_PARM_DESC(pmsg_size, "size of user space message log");
47
48 static unsigned long long mem_address;
49 module_param_hw(mem_address, ullong, other, 0400);
50 MODULE_PARM_DESC(mem_address,
51 "start of reserved RAM used to store oops/panic logs");
52
53 static char *mem_name;
54 module_param_named(mem_name, mem_name, charp, 0400);
55 MODULE_PARM_DESC(mem_name, "name of kernel param that holds addr");
56
57 static ulong mem_size;
58 module_param(mem_size, ulong, 0400);
59 MODULE_PARM_DESC(mem_size,
60 "size of reserved RAM used to store oops/panic logs");
61
62 static unsigned int mem_type;
63 module_param(mem_type, uint, 0400);
64 MODULE_PARM_DESC(mem_type,
65 "memory type: 0=write-combined (default), 1=unbuffered, 2=cached");
66
67 static int ramoops_max_reason = -1;
68 module_param_named(max_reason, ramoops_max_reason, int, 0400);
69 MODULE_PARM_DESC(max_reason,
70 "maximum reason for kmsg dump (default 2: Oops and Panic) ");
71
72 static int ramoops_ecc;
73 module_param_named(ecc, ramoops_ecc, int, 0400);
74 MODULE_PARM_DESC(ramoops_ecc,
75 "if non-zero, the option enables ECC support and specifies "
76 "ECC buffer size in bytes (1 is a special value, means 16 "
77 "bytes ECC)");
78
79 static int ramoops_dump_oops = -1;
80 module_param_named(dump_oops, ramoops_dump_oops, int, 0400);
81 MODULE_PARM_DESC(dump_oops,
82 "(deprecated: use max_reason instead) set to 1 to dump oopses & panics, 0 to only dump panics");
83
84 struct ramoops_context {
85 struct persistent_ram_zone **dprzs; /* Oops dump zones */
86 struct persistent_ram_zone *cprz; /* Console zone */
87 struct persistent_ram_zone **fprzs; /* Ftrace zones */
88 struct persistent_ram_zone *mprz; /* PMSG zone */
89 phys_addr_t phys_addr;
90 unsigned long size;
91 unsigned int memtype;
92 size_t record_size;
93 size_t console_size;
94 size_t ftrace_size;
95 size_t pmsg_size;
96 u32 flags;
97 struct persistent_ram_ecc_info ecc_info;
98 unsigned int max_dump_cnt;
99 unsigned int dump_write_cnt;
100 /* _read_cnt need clear on ramoops_pstore_open */
101 unsigned int dump_read_cnt;
102 unsigned int console_read_cnt;
103 unsigned int max_ftrace_cnt;
104 unsigned int ftrace_read_cnt;
105 unsigned int pmsg_read_cnt;
106 struct pstore_info pstore;
107 };
108
109 static struct platform_device *dummy;
110
111 static int ramoops_pstore_open(struct pstore_info *psi)
112 {
113 struct ramoops_context *cxt = psi->data;
114
115 cxt->dump_read_cnt = 0;
116 cxt->console_read_cnt = 0;
117 cxt->ftrace_read_cnt = 0;
118 cxt->pmsg_read_cnt = 0;
119 return 0;
120 }
121
122 static struct persistent_ram_zone *
123 ramoops_get_next_prz(struct persistent_ram_zone *przs[], int id,
124 struct pstore_record *record)
125 {
126 struct persistent_ram_zone *prz;
127
128 /* Give up if we never existed or have hit the end. */
129 if (!przs)
130 return NULL;
131
132 prz = przs[id];
133 if (!prz)
134 return NULL;
135
136 /* Update old/shadowed buffer. */
137 if (prz->type == PSTORE_TYPE_DMESG)
138 persistent_ram_save_old(prz);
139
140 if (!persistent_ram_old_size(prz))
141 return NULL;
142
143 record->type = prz->type;
144 record->id = id;
145
146 return prz;
147 }
148
149 static int ramoops_read_kmsg_hdr(char *buffer, struct timespec64 *time,
150 bool *compressed)
151 {
152 char data_type;
153 int header_length = 0;
154
155 if (sscanf(buffer, RAMOOPS_KERNMSG_HDR "%lld.%lu-%c\n%n",
156 (time64_t *)&time->tv_sec, &time->tv_nsec, &data_type,
157 &header_length) == 3) {
158 time->tv_nsec *= 1000;
159 if (data_type == 'C')
160 *compressed = true;
161 else
162 *compressed = false;
163 } else if (sscanf(buffer, RAMOOPS_KERNMSG_HDR "%lld.%lu\n%n",
164 (time64_t *)&time->tv_sec, &time->tv_nsec,
165 &header_length) == 2) {
166 time->tv_nsec *= 1000;
167 *compressed = false;
168 } else {
169 time->tv_sec = 0;
170 time->tv_nsec = 0;
171 *compressed = false;
172 }
173 return header_length;
174 }
175
176 static bool prz_ok(struct persistent_ram_zone *prz)
177 {
178 return !!prz && !!(persistent_ram_old_size(prz) +
179 persistent_ram_ecc_string(prz, NULL, 0));
180 }
181
182 static ssize_t ramoops_pstore_read(struct pstore_record *record)
183 {
184 ssize_t size = 0;
185 struct ramoops_context *cxt = record->psi->data;
186 struct persistent_ram_zone *prz = NULL;
187 int header_length = 0;
188 bool free_prz = false;
189
190 /*
191 * Ramoops headers provide time stamps for PSTORE_TYPE_DMESG, but
192 * PSTORE_TYPE_CONSOLE and PSTORE_TYPE_FTRACE don't currently have
193 * valid time stamps, so it is initialized to zero.
194 */
195 record->time.tv_sec = 0;
196 record->time.tv_nsec = 0;
197 record->compressed = false;
198
199 /* Find the next valid persistent_ram_zone for DMESG */
200 while (cxt->dump_read_cnt < cxt->max_dump_cnt && !prz) {
201 prz = ramoops_get_next_prz(cxt->dprzs, cxt->dump_read_cnt++,
202 record);
203 if (!prz_ok(prz))
204 continue;
205 header_length = ramoops_read_kmsg_hdr(persistent_ram_old(prz),
206 &record->time,
207 &record->compressed);
208 /* Clear and skip this DMESG record if it has no valid header */
209 if (!header_length) {
210 persistent_ram_free_old(prz);
211 persistent_ram_zap(prz);
212 prz = NULL;
213 }
214 }
215
216 if (!prz_ok(prz) && !cxt->console_read_cnt++)
217 prz = ramoops_get_next_prz(&cxt->cprz, 0 /* single */, record);
218
219 if (!prz_ok(prz) && !cxt->pmsg_read_cnt++)
220 prz = ramoops_get_next_prz(&cxt->mprz, 0 /* single */, record);
221
222 /* ftrace is last since it may want to dynamically allocate memory. */
223 if (!prz_ok(prz)) {
224 if (!(cxt->flags & RAMOOPS_FLAG_FTRACE_PER_CPU) &&
225 !cxt->ftrace_read_cnt++) {
226 prz = ramoops_get_next_prz(cxt->fprzs, 0 /* single */,
227 record);
228 } else {
229 /*
230 * Build a new dummy record which combines all the
231 * per-cpu records including metadata and ecc info.
232 */
233 struct persistent_ram_zone *tmp_prz, *prz_next;
234
235 tmp_prz = kzalloc(sizeof(struct persistent_ram_zone),
236 GFP_KERNEL);
237 if (!tmp_prz)
238 return -ENOMEM;
239 prz = tmp_prz;
240 free_prz = true;
241
242 while (cxt->ftrace_read_cnt < cxt->max_ftrace_cnt) {
243 prz_next = ramoops_get_next_prz(cxt->fprzs,
244 cxt->ftrace_read_cnt++, record);
245
246 if (!prz_ok(prz_next))
247 continue;
248
249 tmp_prz->ecc_info = prz_next->ecc_info;
250 tmp_prz->corrected_bytes +=
251 prz_next->corrected_bytes;
252 tmp_prz->bad_blocks += prz_next->bad_blocks;
253
254 size = pstore_ftrace_combine_log(
255 &tmp_prz->old_log,
256 &tmp_prz->old_log_size,
257 prz_next->old_log,
258 prz_next->old_log_size);
259 if (size)
260 goto out;
261 }
262 record->id = 0;
263 }
264 }
265
266 if (!prz_ok(prz)) {
267 size = 0;
268 goto out;
269 }
270
271 size = persistent_ram_old_size(prz) - header_length;
272
273 /* ECC correction notice */
274 record->ecc_notice_size = persistent_ram_ecc_string(prz, NULL, 0);
275
276 record->buf = kvzalloc(size + record->ecc_notice_size + 1, GFP_KERNEL);
277 if (record->buf == NULL) {
278 size = -ENOMEM;
279 goto out;
280 }
281
282 memcpy(record->buf, (char *)persistent_ram_old(prz) + header_length,
283 size);
284
285 persistent_ram_ecc_string(prz, record->buf + size,
286 record->ecc_notice_size + 1);
287
288 out:
289 if (free_prz) {
290 kvfree(prz->old_log);
291 kfree(prz);
292 }
293
294 return size;
295 }
296
297 static size_t ramoops_write_kmsg_hdr(struct persistent_ram_zone *prz,
298 struct pstore_record *record)
299 {
300 char hdr[36]; /* "===="(4), %lld(20), "."(1), %06lu(6), "-%c\n"(3) */
301 size_t len;
302
303 len = scnprintf(hdr, sizeof(hdr),
304 RAMOOPS_KERNMSG_HDR "%lld.%06lu-%c\n",
305 (time64_t)record->time.tv_sec,
306 record->time.tv_nsec / 1000,
307 record->compressed ? 'C' : 'D');
308 persistent_ram_write(prz, hdr, len);
309
310 return len;
311 }
312
313 static int notrace ramoops_pstore_write(struct pstore_record *record)
314 {
315 struct ramoops_context *cxt = record->psi->data;
316 struct persistent_ram_zone *prz;
317 size_t size, hlen;
318
319 if (record->type == PSTORE_TYPE_CONSOLE) {
320 if (!cxt->cprz)
321 return -ENOMEM;
322 persistent_ram_write(cxt->cprz, record->buf, record->size);
323 return 0;
324 } else if (record->type == PSTORE_TYPE_FTRACE) {
325 int zonenum;
326
327 if (!cxt->fprzs)
328 return -ENOMEM;
329 /*
330 * Choose zone by if we're using per-cpu buffers.
331 */
332 if (cxt->flags & RAMOOPS_FLAG_FTRACE_PER_CPU)
333 zonenum = smp_processor_id();
334 else
335 zonenum = 0;
336
337 persistent_ram_write(cxt->fprzs[zonenum], record->buf,
338 record->size);
339 return 0;
340 } else if (record->type == PSTORE_TYPE_PMSG) {
341 pr_warn_ratelimited("PMSG shouldn't call %s\n", __func__);
342 return -EINVAL;
343 }
344
345 if (record->type != PSTORE_TYPE_DMESG)
346 return -EINVAL;
347
348 /*
349 * We could filter on record->reason here if we wanted to (which
350 * would duplicate what happened before the "max_reason" setting
351 * was added), but that would defeat the purpose of a system
352 * changing printk.always_kmsg_dump, so instead log everything that
353 * the kmsg dumper sends us, since it should be doing the filtering
354 * based on the combination of printk.always_kmsg_dump and our
355 * requested "max_reason".
356 */
357
358 /*
359 * Explicitly only take the first part of any new crash.
360 * If our buffer is larger than kmsg_bytes, this can never happen,
361 * and if our buffer is smaller than kmsg_bytes, we don't want the
362 * report split across multiple records.
363 */
364 if (record->part != 1)
365 return -ENOSPC;
366
367 if (!cxt->dprzs)
368 return -ENOSPC;
369
370 prz = cxt->dprzs[cxt->dump_write_cnt];
371
372 /*
373 * Since this is a new crash dump, we need to reset the buffer in
374 * case it still has an old dump present. Without this, the new dump
375 * will get appended, which would seriously confuse anything trying
376 * to check dump file contents. Specifically, ramoops_read_kmsg_hdr()
377 * expects to find a dump header in the beginning of buffer data, so
378 * we must to reset the buffer values, in order to ensure that the
379 * header will be written to the beginning of the buffer.
380 */
381 persistent_ram_zap(prz);
382
383 /* Build header and append record contents. */
384 hlen = ramoops_write_kmsg_hdr(prz, record);
385 if (!hlen)
386 return -ENOMEM;
387
388 size = record->size;
389 if (size + hlen > prz->buffer_size)
390 size = prz->buffer_size - hlen;
391 persistent_ram_write(prz, record->buf, size);
392
393 cxt->dump_write_cnt = (cxt->dump_write_cnt + 1) % cxt->max_dump_cnt;
394
395 return 0;
396 }
397
398 static int notrace ramoops_pstore_write_user(struct pstore_record *record,
399 const char __user *buf)
400 {
401 if (record->type == PSTORE_TYPE_PMSG) {
402 struct ramoops_context *cxt = record->psi->data;
403
404 if (!cxt->mprz)
405 return -ENOMEM;
406 return persistent_ram_write_user(cxt->mprz, buf, record->size);
407 }
408
409 return -EINVAL;
410 }
411
412 static int ramoops_pstore_erase(struct pstore_record *record)
413 {
414 struct ramoops_context *cxt = record->psi->data;
415 struct persistent_ram_zone *prz;
416
417 switch (record->type) {
418 case PSTORE_TYPE_DMESG:
419 if (record->id >= cxt->max_dump_cnt)
420 return -EINVAL;
421 prz = cxt->dprzs[record->id];
422 break;
423 case PSTORE_TYPE_CONSOLE:
424 prz = cxt->cprz;
425 break;
426 case PSTORE_TYPE_FTRACE:
427 if (record->id >= cxt->max_ftrace_cnt)
428 return -EINVAL;
429 prz = cxt->fprzs[record->id];
430 break;
431 case PSTORE_TYPE_PMSG:
432 prz = cxt->mprz;
433 break;
434 default:
435 return -EINVAL;
436 }
437
438 persistent_ram_free_old(prz);
439 persistent_ram_zap(prz);
440
441 return 0;
442 }
443
444 static struct ramoops_context oops_cxt = {
445 .pstore = {
446 .owner = THIS_MODULE,
447 .name = "ramoops",
448 .open = ramoops_pstore_open,
449 .read = ramoops_pstore_read,
450 .write = ramoops_pstore_write,
451 .write_user = ramoops_pstore_write_user,
452 .erase = ramoops_pstore_erase,
453 },
454 };
455
456 static void ramoops_free_przs(struct ramoops_context *cxt)
457 {
458 int i;
459
460 /* Free pmsg PRZ */
461 persistent_ram_free(&cxt->mprz);
462
463 /* Free console PRZ */
464 persistent_ram_free(&cxt->cprz);
465
466 /* Free dump PRZs */
467 if (cxt->dprzs) {
468 for (i = 0; i < cxt->max_dump_cnt; i++)
469 persistent_ram_free(&cxt->dprzs[i]);
470
471 kfree(cxt->dprzs);
472 cxt->dprzs = NULL;
473 cxt->max_dump_cnt = 0;
474 }
475
476 /* Free ftrace PRZs */
477 if (cxt->fprzs) {
478 for (i = 0; i < cxt->max_ftrace_cnt; i++)
479 persistent_ram_free(&cxt->fprzs[i]);
480 kfree(cxt->fprzs);
481 cxt->fprzs = NULL;
482 cxt->max_ftrace_cnt = 0;
483 }
484 }
485
486 static int ramoops_init_przs(const char *name,
487 struct device *dev, struct ramoops_context *cxt,
488 struct persistent_ram_zone ***przs,
489 phys_addr_t *paddr, size_t mem_sz,
490 ssize_t record_size,
491 unsigned int *cnt, u32 sig, u32 flags)
492 {
493 int err = -ENOMEM;
494 int i;
495 size_t zone_sz;
496 struct persistent_ram_zone **prz_ar;
497
498 /* Allocate nothing for 0 mem_sz or 0 record_size. */
499 if (mem_sz == 0 || record_size == 0) {
500 *cnt = 0;
501 return 0;
502 }
503
504 /*
505 * If we have a negative record size, calculate it based on
506 * mem_sz / *cnt. If we have a positive record size, calculate
507 * cnt from mem_sz / record_size.
508 */
509 if (record_size < 0) {
510 if (*cnt == 0)
511 return 0;
512 record_size = mem_sz / *cnt;
513 if (record_size == 0) {
514 dev_err(dev, "%s record size == 0 (%zu / %u)\n",
515 name, mem_sz, *cnt);
516 goto fail;
517 }
518 } else {
519 *cnt = mem_sz / record_size;
520 if (*cnt == 0) {
521 dev_err(dev, "%s record count == 0 (%zu / %zu)\n",
522 name, mem_sz, record_size);
523 goto fail;
524 }
525 }
526
527 if (*paddr + mem_sz - cxt->phys_addr > cxt->size) {
528 dev_err(dev, "no room for %s mem region (0x%zx@0x%llx) in (0x%lx@0x%llx)\n",
529 name,
530 mem_sz, (unsigned long long)*paddr,
531 cxt->size, (unsigned long long)cxt->phys_addr);
532 goto fail;
533 }
534
535 zone_sz = mem_sz / *cnt;
536 zone_sz = ALIGN_DOWN(zone_sz, 2);
537 if (!zone_sz) {
538 dev_err(dev, "%s zone size == 0\n", name);
539 goto fail;
540 }
541
542 prz_ar = kcalloc(*cnt, sizeof(**przs), GFP_KERNEL);
543 if (!prz_ar)
544 goto fail;
545
546 for (i = 0; i < *cnt; i++) {
547 char *label;
548
549 if (*cnt == 1)
550 label = kasprintf(GFP_KERNEL, "ramoops:%s", name);
551 else
552 label = kasprintf(GFP_KERNEL, "ramoops:%s(%d/%d)",
553 name, i, *cnt - 1);
554 prz_ar[i] = persistent_ram_new(*paddr, zone_sz, sig,
555 &cxt->ecc_info,
556 cxt->memtype, flags, label);
557 kfree(label);
558 if (IS_ERR(prz_ar[i])) {
559 err = PTR_ERR(prz_ar[i]);
560 dev_err(dev, "failed to request %s mem region (0x%zx@0x%llx): %d\n",
561 name, record_size,
562 (unsigned long long)*paddr, err);
563
564 while (i > 0) {
565 i--;
566 persistent_ram_free(&prz_ar[i]);
567 }
568 kfree(prz_ar);
569 prz_ar = NULL;
570 goto fail;
571 }
572 *paddr += zone_sz;
573 prz_ar[i]->type = pstore_name_to_type(name);
574 }
575
576 *przs = prz_ar;
577 return 0;
578
579 fail:
580 *cnt = 0;
581 return err;
582 }
583
584 static int ramoops_init_prz(const char *name,
585 struct device *dev, struct ramoops_context *cxt,
586 struct persistent_ram_zone **prz,
587 phys_addr_t *paddr, size_t sz, u32 sig)
588 {
589 char *label;
590
591 if (!sz)
592 return 0;
593
594 if (*paddr + sz - cxt->phys_addr > cxt->size) {
595 dev_err(dev, "no room for %s mem region (0x%zx@0x%llx) in (0x%lx@0x%llx)\n",
596 name, sz, (unsigned long long)*paddr,
597 cxt->size, (unsigned long long)cxt->phys_addr);
598 return -ENOMEM;
599 }
600
601 label = kasprintf(GFP_KERNEL, "ramoops:%s", name);
602 *prz = persistent_ram_new(*paddr, sz, sig, &cxt->ecc_info,
603 cxt->memtype, PRZ_FLAG_ZAP_OLD, label);
604 kfree(label);
605 if (IS_ERR(*prz)) {
606 int err = PTR_ERR(*prz);
607
608 dev_err(dev, "failed to request %s mem region (0x%zx@0x%llx): %d\n",
609 name, sz, (unsigned long long)*paddr, err);
610 return err;
611 }
612
613 *paddr += sz;
614 (*prz)->type = pstore_name_to_type(name);
615
616 return 0;
617 }
618
619 /* Read a u32 from a dt property and make sure it's safe for an int. */
620 static int ramoops_parse_dt_u32(struct platform_device *pdev,
621 const char *propname,
622 u32 default_value, u32 *value)
623 {
624 u32 val32 = 0;
625 int ret;
626
627 ret = of_property_read_u32(pdev->dev.of_node, propname, &val32);
628 if (ret == -EINVAL) {
629 /* field is missing, use default value. */
630 val32 = default_value;
631 } else if (ret < 0) {
632 dev_err(&pdev->dev, "failed to parse property %s: %d\n",
633 propname, ret);
634 return ret;
635 }
636
637 /* Sanity check our results. */
638 if (val32 > INT_MAX) {
639 dev_err(&pdev->dev, "%s %u > INT_MAX\n", propname, val32);
640 return -EOVERFLOW;
641 }
642
643 *value = val32;
644 return 0;
645 }
646
647 static int ramoops_parse_dt(struct platform_device *pdev,
648 struct ramoops_platform_data *pdata)
649 {
650 struct device_node *of_node = pdev->dev.of_node;
651 struct device_node *parent_node;
652 struct resource *res;
653 u32 value;
654 int ret;
655
656 dev_dbg(&pdev->dev, "using Device Tree\n");
657
658 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
659 if (!res) {
660 dev_err(&pdev->dev,
661 "failed to locate DT /reserved-memory resource\n");
662 return -EINVAL;
663 }
664
665 pdata->mem_size = resource_size(res);
666 pdata->mem_address = res->start;
667 /*
668 * Setting "unbuffered" is deprecated and will be ignored if
669 * "mem_type" is also specified.
670 */
671 pdata->mem_type = of_property_read_bool(of_node, "unbuffered");
672 /*
673 * Setting "no-dump-oops" is deprecated and will be ignored if
674 * "max_reason" is also specified.
675 */
676 if (of_property_read_bool(of_node, "no-dump-oops"))
677 pdata->max_reason = KMSG_DUMP_PANIC;
678 else
679 pdata->max_reason = KMSG_DUMP_OOPS;
680
681 #define parse_u32(name, field, default_value) { \
682 ret = ramoops_parse_dt_u32(pdev, name, default_value, \
683 &value); \
684 if (ret < 0) \
685 return ret; \
686 field = value; \
687 }
688
689 parse_u32("mem-type", pdata->mem_type, pdata->mem_type);
690 parse_u32("record-size", pdata->record_size, 0);
691 parse_u32("console-size", pdata->console_size, 0);
692 parse_u32("ftrace-size", pdata->ftrace_size, 0);
693 parse_u32("pmsg-size", pdata->pmsg_size, 0);
694 parse_u32("ecc-size", pdata->ecc_info.ecc_size, 0);
695 parse_u32("flags", pdata->flags, 0);
696 parse_u32("max-reason", pdata->max_reason, pdata->max_reason);
697
698 #undef parse_u32
699
700 /*
701 * Some old Chromebooks relied on the kernel setting the
702 * console_size and pmsg_size to the record size since that's
703 * what the downstream kernel did. These same Chromebooks had
704 * "ramoops" straight under the root node which isn't
705 * according to the current upstream bindings (though it was
706 * arguably acceptable under a prior version of the bindings).
707 * Let's make those old Chromebooks work by detecting that
708 * we're not a child of "reserved-memory" and mimicking the
709 * expected behavior.
710 */
711 parent_node = of_get_parent(of_node);
712 if (!of_node_name_eq(parent_node, "reserved-memory") &&
713 !pdata->console_size && !pdata->ftrace_size &&
714 !pdata->pmsg_size && !pdata->ecc_info.ecc_size) {
715 pdata->console_size = pdata->record_size;
716 pdata->pmsg_size = pdata->record_size;
717 }
718 of_node_put(parent_node);
719
720 return 0;
721 }
722
723 static int ramoops_probe(struct platform_device *pdev)
724 {
725 struct device *dev = &pdev->dev;
726 struct ramoops_platform_data *pdata = dev->platform_data;
727 struct ramoops_platform_data pdata_local;
728 struct ramoops_context *cxt = &oops_cxt;
729 size_t dump_mem_sz;
730 phys_addr_t paddr;
731 int err = -EINVAL;
732
733 /*
734 * Only a single ramoops area allowed at a time, so fail extra
735 * probes.
736 */
737 if (cxt->max_dump_cnt) {
738 pr_err("already initialized\n");
739 goto fail_out;
740 }
741
742 if (dev_of_node(dev) && !pdata) {
743 pdata = &pdata_local;
744 memset(pdata, 0, sizeof(*pdata));
745
746 err = ramoops_parse_dt(pdev, pdata);
747 if (err < 0)
748 goto fail_out;
749 }
750
751 /* Make sure we didn't get bogus platform data pointer. */
752 if (!pdata) {
753 pr_err("NULL platform data\n");
754 err = -EINVAL;
755 goto fail_out;
756 }
757
758 if (!pdata->mem_size || (!pdata->record_size && !pdata->console_size &&
759 !pdata->ftrace_size && !pdata->pmsg_size)) {
760 pr_err("The memory size and the record/console size must be "
761 "non-zero\n");
762 err = -EINVAL;
763 goto fail_out;
764 }
765
766 if (pdata->record_size && !is_power_of_2(pdata->record_size))
767 pdata->record_size = rounddown_pow_of_two(pdata->record_size);
768 if (pdata->console_size && !is_power_of_2(pdata->console_size))
769 pdata->console_size = rounddown_pow_of_two(pdata->console_size);
770 if (pdata->ftrace_size && !is_power_of_2(pdata->ftrace_size))
771 pdata->ftrace_size = rounddown_pow_of_two(pdata->ftrace_size);
772 if (pdata->pmsg_size && !is_power_of_2(pdata->pmsg_size))
773 pdata->pmsg_size = rounddown_pow_of_two(pdata->pmsg_size);
774
775 cxt->size = pdata->mem_size;
776 cxt->phys_addr = pdata->mem_address;
777 cxt->memtype = pdata->mem_type;
778 cxt->record_size = pdata->record_size;
779 cxt->console_size = pdata->console_size;
780 cxt->ftrace_size = pdata->ftrace_size;
781 cxt->pmsg_size = pdata->pmsg_size;
782 cxt->flags = pdata->flags;
783 cxt->ecc_info = pdata->ecc_info;
784
785 paddr = cxt->phys_addr;
786
787 dump_mem_sz = cxt->size - cxt->console_size - cxt->ftrace_size
788 - cxt->pmsg_size;
789 err = ramoops_init_przs("dmesg", dev, cxt, &cxt->dprzs, &paddr,
790 dump_mem_sz, cxt->record_size,
791 &cxt->max_dump_cnt, 0, 0);
792 if (err)
793 goto fail_init;
794
795 err = ramoops_init_prz("console", dev, cxt, &cxt->cprz, &paddr,
796 cxt->console_size, 0);
797 if (err)
798 goto fail_init;
799
800 err = ramoops_init_prz("pmsg", dev, cxt, &cxt->mprz, &paddr,
801 cxt->pmsg_size, 0);
802 if (err)
803 goto fail_init;
804
805 cxt->max_ftrace_cnt = (cxt->flags & RAMOOPS_FLAG_FTRACE_PER_CPU)
806 ? nr_cpu_ids
807 : 1;
808 err = ramoops_init_przs("ftrace", dev, cxt, &cxt->fprzs, &paddr,
809 cxt->ftrace_size, -1,
810 &cxt->max_ftrace_cnt, LINUX_VERSION_CODE,
811 (cxt->flags & RAMOOPS_FLAG_FTRACE_PER_CPU)
812 ? PRZ_FLAG_NO_LOCK : 0);
813 if (err)
814 goto fail_init;
815
816 cxt->pstore.data = cxt;
817 /*
818 * Prepare frontend flags based on which areas are initialized.
819 * For ramoops_init_przs() cases, the "max count" variable tells
820 * if there are regions present. For ramoops_init_prz() cases,
821 * the single region size is how to check.
822 */
823 cxt->pstore.flags = 0;
824 if (cxt->max_dump_cnt) {
825 cxt->pstore.flags |= PSTORE_FLAGS_DMESG;
826 cxt->pstore.max_reason = pdata->max_reason;
827 }
828 if (cxt->console_size)
829 cxt->pstore.flags |= PSTORE_FLAGS_CONSOLE;
830 if (cxt->max_ftrace_cnt)
831 cxt->pstore.flags |= PSTORE_FLAGS_FTRACE;
832 if (cxt->pmsg_size)
833 cxt->pstore.flags |= PSTORE_FLAGS_PMSG;
834
835 /*
836 * Since bufsize is only used for dmesg crash dumps, it
837 * must match the size of the dprz record (after PRZ header
838 * and ECC bytes have been accounted for).
839 */
840 if (cxt->pstore.flags & PSTORE_FLAGS_DMESG) {
841 cxt->pstore.bufsize = cxt->dprzs[0]->buffer_size;
842 cxt->pstore.buf = kvzalloc(cxt->pstore.bufsize, GFP_KERNEL);
843 if (!cxt->pstore.buf) {
844 pr_err("cannot allocate pstore crash dump buffer\n");
845 err = -ENOMEM;
846 goto fail_clear;
847 }
848 }
849
850 err = pstore_register(&cxt->pstore);
851 if (err) {
852 pr_err("registering with pstore failed\n");
853 goto fail_buf;
854 }
855
856 /*
857 * Update the module parameter variables as well so they are visible
858 * through /sys/module/ramoops/parameters/
859 */
860 mem_size = pdata->mem_size;
861 mem_address = pdata->mem_address;
862 record_size = pdata->record_size;
863 ramoops_max_reason = pdata->max_reason;
864 ramoops_console_size = pdata->console_size;
865 ramoops_pmsg_size = pdata->pmsg_size;
866 ramoops_ftrace_size = pdata->ftrace_size;
867
868 pr_info("using 0x%lx@0x%llx, ecc: %d\n",
869 cxt->size, (unsigned long long)cxt->phys_addr,
870 cxt->ecc_info.ecc_size);
871
872 return 0;
873
874 fail_buf:
875 kvfree(cxt->pstore.buf);
876 fail_clear:
877 cxt->pstore.bufsize = 0;
878 fail_init:
879 ramoops_free_przs(cxt);
880 fail_out:
881 return err;
882 }
883
884 static void ramoops_remove(struct platform_device *pdev)
885 {
886 struct ramoops_context *cxt = &oops_cxt;
887
888 pstore_unregister(&cxt->pstore);
889
890 kvfree(cxt->pstore.buf);
891 cxt->pstore.bufsize = 0;
892
893 ramoops_free_przs(cxt);
894 }
895
896 static const struct of_device_id dt_match[] = {
897 { .compatible = "ramoops" },
898 {}
899 };
900 MODULE_DEVICE_TABLE(of, dt_match);
901
902 static struct platform_driver ramoops_driver = {
903 .probe = ramoops_probe,
904 .remove_new = ramoops_remove,
905 .driver = {
906 .name = "ramoops",
907 .of_match_table = dt_match,
908 },
909 };
910
911 static inline void ramoops_unregister_dummy(void)
912 {
913 platform_device_unregister(dummy);
914 dummy = NULL;
915 }
916
917 static void __init ramoops_register_dummy(void)
918 {
919 struct ramoops_platform_data pdata;
920
921 if (mem_name) {
922 phys_addr_t start;
923 phys_addr_t size;
924
925 if (reserve_mem_find_by_name(mem_name, &start, &size)) {
926 mem_address = start;
927 mem_size = size;
928 }
929 }
930
931 /*
932 * Prepare a dummy platform data structure to carry the module
933 * parameters. If mem_size isn't set, then there are no module
934 * parameters, and we can skip this.
935 */
936 if (!mem_size)
937 return;
938
939 pr_info("using module parameters\n");
940
941 memset(&pdata, 0, sizeof(pdata));
942 pdata.mem_size = mem_size;
943 pdata.mem_address = mem_address;
944 pdata.mem_type = mem_type;
945 pdata.record_size = record_size;
946 pdata.console_size = ramoops_console_size;
947 pdata.ftrace_size = ramoops_ftrace_size;
948 pdata.pmsg_size = ramoops_pmsg_size;
949 /* If "max_reason" is set, its value has priority over "dump_oops". */
950 if (ramoops_max_reason >= 0)
951 pdata.max_reason = ramoops_max_reason;
952 /* Otherwise, if "dump_oops" is set, parse it into "max_reason". */
953 else if (ramoops_dump_oops != -1)
954 pdata.max_reason = ramoops_dump_oops ? KMSG_DUMP_OOPS
955 : KMSG_DUMP_PANIC;
956 /* And if neither are explicitly set, use the default. */
957 else
958 pdata.max_reason = KMSG_DUMP_OOPS;
959 pdata.flags = RAMOOPS_FLAG_FTRACE_PER_CPU;
960
961 /*
962 * For backwards compatibility ramoops.ecc=1 means 16 bytes ECC
963 * (using 1 byte for ECC isn't much of use anyway).
964 */
965 pdata.ecc_info.ecc_size = ramoops_ecc == 1 ? 16 : ramoops_ecc;
966
967 dummy = platform_device_register_data(NULL, "ramoops", -1,
968 &pdata, sizeof(pdata));
969 if (IS_ERR(dummy)) {
970 pr_info("could not create platform device: %ld\n",
971 PTR_ERR(dummy));
972 dummy = NULL;
973 }
974 }
975
976 static int __init ramoops_init(void)
977 {
978 int ret;
979
980 ramoops_register_dummy();
981 ret = platform_driver_register(&ramoops_driver);
982 if (ret != 0)
983 ramoops_unregister_dummy();
984
985 return ret;
986 }
987 postcore_initcall(ramoops_init);
988
989 static void __exit ramoops_exit(void)
990 {
991 platform_driver_unregister(&ramoops_driver);
992 ramoops_unregister_dummy();
993 }
994 module_exit(ramoops_exit);
995
996 MODULE_LICENSE("GPL");
997 MODULE_AUTHOR("Marco Stornelli <marco.stornelli@gmail.com>");
998 MODULE_DESCRIPTION("RAM Oops/Panic logger/driver");
999
Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.