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