1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * crash.c - kernel crash support code.
4 * Copyright (C) 2002-2004 Eric Biederman <ebiederm@xmission.com>
5 */
6
7 #include <linux/crash_core.h>
8 #include <linux/utsname.h>
9 #include <linux/vmalloc.h>
10
11 #include <asm/page.h>
12 #include <asm/sections.h>
13
14 #include <crypto/sha1.h>
15
16 /* vmcoreinfo stuff */
17 unsigned char *vmcoreinfo_data;
18 size_t vmcoreinfo_size;
19 u32 *vmcoreinfo_note;
20
21 /* trusted vmcoreinfo, e.g. we can make a copy in the crash memory */
22 static unsigned char *vmcoreinfo_data_safecopy;
23
24 /*
25 * parsing the "crashkernel" commandline
26 *
27 * this code is intended to be called from architecture specific code
28 */
29
30
31 /*
32 * This function parses command lines in the format
33 *
34 * crashkernel=ramsize-range:size[,...][@offset]
35 *
36 * The function returns 0 on success and -EINVAL on failure.
37 */
parse_crashkernel_mem(char * cmdline,unsigned long long system_ram,unsigned long long * crash_size,unsigned long long * crash_base)38 static int __init parse_crashkernel_mem(char *cmdline,
39 unsigned long long system_ram,
40 unsigned long long *crash_size,
41 unsigned long long *crash_base)
42 {
43 char *cur = cmdline, *tmp;
44
45 /* for each entry of the comma-separated list */
46 do {
47 unsigned long long start, end = ULLONG_MAX, size;
48
49 /* get the start of the range */
50 start = memparse(cur, &tmp);
51 if (cur == tmp) {
52 pr_warn("crashkernel: Memory value expected\n");
53 return -EINVAL;
54 }
55 cur = tmp;
56 if (*cur != '-') {
57 pr_warn("crashkernel: '-' expected\n");
58 return -EINVAL;
59 }
60 cur++;
61
62 /* if no ':' is here, than we read the end */
63 if (*cur != ':') {
64 end = memparse(cur, &tmp);
65 if (cur == tmp) {
66 pr_warn("crashkernel: Memory value expected\n");
67 return -EINVAL;
68 }
69 cur = tmp;
70 if (end <= start) {
71 pr_warn("crashkernel: end <= start\n");
72 return -EINVAL;
73 }
74 }
75
76 if (*cur != ':') {
77 pr_warn("crashkernel: ':' expected\n");
78 return -EINVAL;
79 }
80 cur++;
81
82 size = memparse(cur, &tmp);
83 if (cur == tmp) {
84 pr_warn("Memory value expected\n");
85 return -EINVAL;
86 }
87 cur = tmp;
88 if (size >= system_ram) {
89 pr_warn("crashkernel: invalid size\n");
90 return -EINVAL;
91 }
92
93 /* match ? */
94 if (system_ram >= start && system_ram < end) {
95 *crash_size = size;
96 break;
97 }
98 } while (*cur++ == ',');
99
100 if (*crash_size > 0) {
101 while (*cur && *cur != ' ' && *cur != '@')
102 cur++;
103 if (*cur == '@') {
104 cur++;
105 *crash_base = memparse(cur, &tmp);
106 if (cur == tmp) {
107 pr_warn("Memory value expected after '@'\n");
108 return -EINVAL;
109 }
110 }
111 } else
112 pr_info("crashkernel size resulted in zero bytes\n");
113
114 return 0;
115 }
116
117 /*
118 * That function parses "simple" (old) crashkernel command lines like
119 *
120 * crashkernel=size[@offset]
121 *
122 * It returns 0 on success and -EINVAL on failure.
123 */
parse_crashkernel_simple(char * cmdline,unsigned long long * crash_size,unsigned long long * crash_base)124 static int __init parse_crashkernel_simple(char *cmdline,
125 unsigned long long *crash_size,
126 unsigned long long *crash_base)
127 {
128 char *cur = cmdline;
129
130 *crash_size = memparse(cmdline, &cur);
131 if (cmdline == cur) {
132 pr_warn("crashkernel: memory value expected\n");
133 return -EINVAL;
134 }
135
136 if (*cur == '@')
137 *crash_base = memparse(cur+1, &cur);
138 else if (*cur != ' ' && *cur != '\0') {
139 pr_warn("crashkernel: unrecognized char: %c\n", *cur);
140 return -EINVAL;
141 }
142
143 return 0;
144 }
145
146 #define SUFFIX_HIGH 0
147 #define SUFFIX_LOW 1
148 #define SUFFIX_NULL 2
149 static __initdata char *suffix_tbl[] = {
150 [SUFFIX_HIGH] = ",high",
151 [SUFFIX_LOW] = ",low",
152 [SUFFIX_NULL] = NULL,
153 };
154
155 /*
156 * That function parses "suffix" crashkernel command lines like
157 *
158 * crashkernel=size,[high|low]
159 *
160 * It returns 0 on success and -EINVAL on failure.
161 */
parse_crashkernel_suffix(char * cmdline,unsigned long long * crash_size,const char * suffix)162 static int __init parse_crashkernel_suffix(char *cmdline,
163 unsigned long long *crash_size,
164 const char *suffix)
165 {
166 char *cur = cmdline;
167
168 *crash_size = memparse(cmdline, &cur);
169 if (cmdline == cur) {
170 pr_warn("crashkernel: memory value expected\n");
171 return -EINVAL;
172 }
173
174 /* check with suffix */
175 if (strncmp(cur, suffix, strlen(suffix))) {
176 pr_warn("crashkernel: unrecognized char: %c\n", *cur);
177 return -EINVAL;
178 }
179 cur += strlen(suffix);
180 if (*cur != ' ' && *cur != '\0') {
181 pr_warn("crashkernel: unrecognized char: %c\n", *cur);
182 return -EINVAL;
183 }
184
185 return 0;
186 }
187
get_last_crashkernel(char * cmdline,const char * name,const char * suffix)188 static __init char *get_last_crashkernel(char *cmdline,
189 const char *name,
190 const char *suffix)
191 {
192 char *p = cmdline, *ck_cmdline = NULL;
193
194 /* find crashkernel and use the last one if there are more */
195 p = strstr(p, name);
196 while (p) {
197 char *end_p = strchr(p, ' ');
198 char *q;
199
200 if (!end_p)
201 end_p = p + strlen(p);
202
203 if (!suffix) {
204 int i;
205
206 /* skip the one with any known suffix */
207 for (i = 0; suffix_tbl[i]; i++) {
208 q = end_p - strlen(suffix_tbl[i]);
209 if (!strncmp(q, suffix_tbl[i],
210 strlen(suffix_tbl[i])))
211 goto next;
212 }
213 ck_cmdline = p;
214 } else {
215 q = end_p - strlen(suffix);
216 if (!strncmp(q, suffix, strlen(suffix)))
217 ck_cmdline = p;
218 }
219 next:
220 p = strstr(p+1, name);
221 }
222
223 if (!ck_cmdline)
224 return NULL;
225
226 return ck_cmdline;
227 }
228
__parse_crashkernel(char * cmdline,unsigned long long system_ram,unsigned long long * crash_size,unsigned long long * crash_base,const char * name,const char * suffix)229 static int __init __parse_crashkernel(char *cmdline,
230 unsigned long long system_ram,
231 unsigned long long *crash_size,
232 unsigned long long *crash_base,
233 const char *name,
234 const char *suffix)
235 {
236 char *first_colon, *first_space;
237 char *ck_cmdline;
238
239 BUG_ON(!crash_size || !crash_base);
240 *crash_size = 0;
241 *crash_base = 0;
242
243 ck_cmdline = get_last_crashkernel(cmdline, name, suffix);
244
245 if (!ck_cmdline)
246 return -EINVAL;
247
248 ck_cmdline += strlen(name);
249
250 if (suffix)
251 return parse_crashkernel_suffix(ck_cmdline, crash_size,
252 suffix);
253 /*
254 * if the commandline contains a ':', then that's the extended
255 * syntax -- if not, it must be the classic syntax
256 */
257 first_colon = strchr(ck_cmdline, ':');
258 first_space = strchr(ck_cmdline, ' ');
259 if (first_colon && (!first_space || first_colon < first_space))
260 return parse_crashkernel_mem(ck_cmdline, system_ram,
261 crash_size, crash_base);
262
263 return parse_crashkernel_simple(ck_cmdline, crash_size, crash_base);
264 }
265
266 /*
267 * That function is the entry point for command line parsing and should be
268 * called from the arch-specific code.
269 */
parse_crashkernel(char * cmdline,unsigned long long system_ram,unsigned long long * crash_size,unsigned long long * crash_base)270 int __init parse_crashkernel(char *cmdline,
271 unsigned long long system_ram,
272 unsigned long long *crash_size,
273 unsigned long long *crash_base)
274 {
275 return __parse_crashkernel(cmdline, system_ram, crash_size, crash_base,
276 "crashkernel=", NULL);
277 }
278
parse_crashkernel_high(char * cmdline,unsigned long long system_ram,unsigned long long * crash_size,unsigned long long * crash_base)279 int __init parse_crashkernel_high(char *cmdline,
280 unsigned long long system_ram,
281 unsigned long long *crash_size,
282 unsigned long long *crash_base)
283 {
284 return __parse_crashkernel(cmdline, system_ram, crash_size, crash_base,
285 "crashkernel=", suffix_tbl[SUFFIX_HIGH]);
286 }
287
parse_crashkernel_low(char * cmdline,unsigned long long system_ram,unsigned long long * crash_size,unsigned long long * crash_base)288 int __init parse_crashkernel_low(char *cmdline,
289 unsigned long long system_ram,
290 unsigned long long *crash_size,
291 unsigned long long *crash_base)
292 {
293 return __parse_crashkernel(cmdline, system_ram, crash_size, crash_base,
294 "crashkernel=", suffix_tbl[SUFFIX_LOW]);
295 }
296
append_elf_note(Elf_Word * buf,char * name,unsigned int type,void * data,size_t data_len)297 Elf_Word *append_elf_note(Elf_Word *buf, char *name, unsigned int type,
298 void *data, size_t data_len)
299 {
300 struct elf_note *note = (struct elf_note *)buf;
301
302 note->n_namesz = strlen(name) + 1;
303 note->n_descsz = data_len;
304 note->n_type = type;
305 buf += DIV_ROUND_UP(sizeof(*note), sizeof(Elf_Word));
306 memcpy(buf, name, note->n_namesz);
307 buf += DIV_ROUND_UP(note->n_namesz, sizeof(Elf_Word));
308 memcpy(buf, data, data_len);
309 buf += DIV_ROUND_UP(data_len, sizeof(Elf_Word));
310
311 return buf;
312 }
313
final_note(Elf_Word * buf)314 void final_note(Elf_Word *buf)
315 {
316 memset(buf, 0, sizeof(struct elf_note));
317 }
318
update_vmcoreinfo_note(void)319 static void update_vmcoreinfo_note(void)
320 {
321 u32 *buf = vmcoreinfo_note;
322
323 if (!vmcoreinfo_size)
324 return;
325 buf = append_elf_note(buf, VMCOREINFO_NOTE_NAME, 0, vmcoreinfo_data,
326 vmcoreinfo_size);
327 final_note(buf);
328 }
329
crash_update_vmcoreinfo_safecopy(void * ptr)330 void crash_update_vmcoreinfo_safecopy(void *ptr)
331 {
332 if (ptr)
333 memcpy(ptr, vmcoreinfo_data, vmcoreinfo_size);
334
335 vmcoreinfo_data_safecopy = ptr;
336 }
337
crash_save_vmcoreinfo(void)338 void crash_save_vmcoreinfo(void)
339 {
340 if (!vmcoreinfo_note)
341 return;
342
343 /* Use the safe copy to generate vmcoreinfo note if have */
344 if (vmcoreinfo_data_safecopy)
345 vmcoreinfo_data = vmcoreinfo_data_safecopy;
346
347 vmcoreinfo_append_str("CRASHTIME=%lld\n", ktime_get_real_seconds());
348 update_vmcoreinfo_note();
349 }
350
vmcoreinfo_append_str(const char * fmt,...)351 void vmcoreinfo_append_str(const char *fmt, ...)
352 {
353 va_list args;
354 char buf[0x50];
355 size_t r;
356
357 va_start(args, fmt);
358 r = vscnprintf(buf, sizeof(buf), fmt, args);
359 va_end(args);
360
361 r = min(r, (size_t)VMCOREINFO_BYTES - vmcoreinfo_size);
362
363 memcpy(&vmcoreinfo_data[vmcoreinfo_size], buf, r);
364
365 vmcoreinfo_size += r;
366 }
367
368 /*
369 * provide an empty default implementation here -- architecture
370 * code may override this
371 */
arch_crash_save_vmcoreinfo(void)372 void __weak arch_crash_save_vmcoreinfo(void)
373 {}
374
paddr_vmcoreinfo_note(void)375 phys_addr_t __weak paddr_vmcoreinfo_note(void)
376 {
377 return __pa(vmcoreinfo_note);
378 }
379 EXPORT_SYMBOL(paddr_vmcoreinfo_note);
380
381 #define NOTES_SIZE (&__stop_notes - &__start_notes)
382 #define BUILD_ID_MAX SHA1_DIGEST_SIZE
383 #define NT_GNU_BUILD_ID 3
384
385 struct elf_note_section {
386 struct elf_note n_hdr;
387 u8 n_data[];
388 };
389
390 /*
391 * Add build ID from .notes section as generated by the GNU ld(1)
392 * or LLVM lld(1) --build-id option.
393 */
add_build_id_vmcoreinfo(void)394 static void add_build_id_vmcoreinfo(void)
395 {
396 char build_id[BUILD_ID_MAX * 2 + 1];
397 int n_remain = NOTES_SIZE;
398
399 while (n_remain >= sizeof(struct elf_note)) {
400 const struct elf_note_section *note_sec =
401 &__start_notes + NOTES_SIZE - n_remain;
402 const u32 n_namesz = note_sec->n_hdr.n_namesz;
403
404 if (note_sec->n_hdr.n_type == NT_GNU_BUILD_ID &&
405 n_namesz != 0 &&
406 !strcmp((char *)¬e_sec->n_data[0], "GNU")) {
407 if (note_sec->n_hdr.n_descsz <= BUILD_ID_MAX) {
408 const u32 n_descsz = note_sec->n_hdr.n_descsz;
409 const u8 *s = ¬e_sec->n_data[n_namesz];
410
411 s = PTR_ALIGN(s, 4);
412 bin2hex(build_id, s, n_descsz);
413 build_id[2 * n_descsz] = '\0';
414 VMCOREINFO_BUILD_ID(build_id);
415 return;
416 }
417 pr_warn("Build ID is too large to include in vmcoreinfo: %u > %u\n",
418 note_sec->n_hdr.n_descsz,
419 BUILD_ID_MAX);
420 return;
421 }
422 n_remain -= sizeof(struct elf_note) +
423 ALIGN(note_sec->n_hdr.n_namesz, 4) +
424 ALIGN(note_sec->n_hdr.n_descsz, 4);
425 }
426 }
427
crash_save_vmcoreinfo_init(void)428 static int __init crash_save_vmcoreinfo_init(void)
429 {
430 vmcoreinfo_data = (unsigned char *)get_zeroed_page(GFP_KERNEL);
431 if (!vmcoreinfo_data) {
432 pr_warn("Memory allocation for vmcoreinfo_data failed\n");
433 return -ENOMEM;
434 }
435
436 vmcoreinfo_note = alloc_pages_exact(VMCOREINFO_NOTE_SIZE,
437 GFP_KERNEL | __GFP_ZERO);
438 if (!vmcoreinfo_note) {
439 free_page((unsigned long)vmcoreinfo_data);
440 vmcoreinfo_data = NULL;
441 pr_warn("Memory allocation for vmcoreinfo_note failed\n");
442 return -ENOMEM;
443 }
444
445 VMCOREINFO_OSRELEASE(init_uts_ns.name.release);
446 add_build_id_vmcoreinfo();
447 VMCOREINFO_PAGESIZE(PAGE_SIZE);
448
449 VMCOREINFO_SYMBOL(init_uts_ns);
450 VMCOREINFO_OFFSET(uts_namespace, name);
451 VMCOREINFO_SYMBOL(node_online_map);
452 #ifdef CONFIG_MMU
453 VMCOREINFO_SYMBOL_ARRAY(swapper_pg_dir);
454 #endif
455 VMCOREINFO_SYMBOL(_stext);
456 VMCOREINFO_SYMBOL(vmap_area_list);
457
458 #ifndef CONFIG_NEED_MULTIPLE_NODES
459 VMCOREINFO_SYMBOL(mem_map);
460 VMCOREINFO_SYMBOL(contig_page_data);
461 #endif
462 #ifdef CONFIG_SPARSEMEM
463 VMCOREINFO_SYMBOL_ARRAY(mem_section);
464 VMCOREINFO_LENGTH(mem_section, NR_SECTION_ROOTS);
465 VMCOREINFO_STRUCT_SIZE(mem_section);
466 VMCOREINFO_OFFSET(mem_section, section_mem_map);
467 VMCOREINFO_NUMBER(MAX_PHYSMEM_BITS);
468 #endif
469 VMCOREINFO_STRUCT_SIZE(page);
470 VMCOREINFO_STRUCT_SIZE(pglist_data);
471 VMCOREINFO_STRUCT_SIZE(zone);
472 VMCOREINFO_STRUCT_SIZE(free_area);
473 VMCOREINFO_STRUCT_SIZE(list_head);
474 VMCOREINFO_SIZE(nodemask_t);
475 VMCOREINFO_OFFSET(page, flags);
476 VMCOREINFO_OFFSET(page, _refcount);
477 VMCOREINFO_OFFSET(page, mapping);
478 VMCOREINFO_OFFSET(page, lru);
479 VMCOREINFO_OFFSET(page, _mapcount);
480 VMCOREINFO_OFFSET(page, private);
481 VMCOREINFO_OFFSET(page, compound_dtor);
482 VMCOREINFO_OFFSET(page, compound_order);
483 VMCOREINFO_OFFSET(page, compound_head);
484 VMCOREINFO_OFFSET(pglist_data, node_zones);
485 VMCOREINFO_OFFSET(pglist_data, nr_zones);
486 #ifdef CONFIG_FLAT_NODE_MEM_MAP
487 VMCOREINFO_OFFSET(pglist_data, node_mem_map);
488 #endif
489 VMCOREINFO_OFFSET(pglist_data, node_start_pfn);
490 VMCOREINFO_OFFSET(pglist_data, node_spanned_pages);
491 VMCOREINFO_OFFSET(pglist_data, node_id);
492 VMCOREINFO_OFFSET(zone, free_area);
493 VMCOREINFO_OFFSET(zone, vm_stat);
494 VMCOREINFO_OFFSET(zone, spanned_pages);
495 VMCOREINFO_OFFSET(free_area, free_list);
496 VMCOREINFO_OFFSET(list_head, next);
497 VMCOREINFO_OFFSET(list_head, prev);
498 VMCOREINFO_OFFSET(vmap_area, va_start);
499 VMCOREINFO_OFFSET(vmap_area, list);
500 VMCOREINFO_LENGTH(zone.free_area, MAX_ORDER);
501 log_buf_vmcoreinfo_setup();
502 VMCOREINFO_LENGTH(free_area.free_list, MIGRATE_TYPES);
503 VMCOREINFO_NUMBER(NR_FREE_PAGES);
504 VMCOREINFO_NUMBER(PG_lru);
505 VMCOREINFO_NUMBER(PG_private);
506 VMCOREINFO_NUMBER(PG_swapcache);
507 VMCOREINFO_NUMBER(PG_swapbacked);
508 VMCOREINFO_NUMBER(PG_slab);
509 #ifdef CONFIG_MEMORY_FAILURE
510 VMCOREINFO_NUMBER(PG_hwpoison);
511 #endif
512 VMCOREINFO_NUMBER(PG_head_mask);
513 #define PAGE_BUDDY_MAPCOUNT_VALUE (~PG_buddy)
514 VMCOREINFO_NUMBER(PAGE_BUDDY_MAPCOUNT_VALUE);
515 #ifdef CONFIG_HUGETLB_PAGE
516 VMCOREINFO_NUMBER(HUGETLB_PAGE_DTOR);
517 #define PAGE_OFFLINE_MAPCOUNT_VALUE (~PG_offline)
518 VMCOREINFO_NUMBER(PAGE_OFFLINE_MAPCOUNT_VALUE);
519 #endif
520
521 arch_crash_save_vmcoreinfo();
522 update_vmcoreinfo_note();
523
524 return 0;
525 }
526
527 subsys_initcall(crash_save_vmcoreinfo_init);
528