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