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