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 return ck_cmdline;
226 }
227
__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)228 static int __init __parse_crashkernel(char *cmdline,
229 unsigned long long system_ram,
230 unsigned long long *crash_size,
231 unsigned long long *crash_base,
232 const char *name,
233 const char *suffix)
234 {
235 char *first_colon, *first_space;
236 char *ck_cmdline;
237
238 BUG_ON(!crash_size || !crash_base);
239 *crash_size = 0;
240 *crash_base = 0;
241
242 ck_cmdline = get_last_crashkernel(cmdline, name, suffix);
243 if (!ck_cmdline)
244 return -ENOENT;
245
246 ck_cmdline += strlen(name);
247
248 if (suffix)
249 return parse_crashkernel_suffix(ck_cmdline, crash_size,
250 suffix);
251 /*
252 * if the commandline contains a ':', then that's the extended
253 * syntax -- if not, it must be the classic syntax
254 */
255 first_colon = strchr(ck_cmdline, ':');
256 first_space = strchr(ck_cmdline, ' ');
257 if (first_colon && (!first_space || first_colon < first_space))
258 return parse_crashkernel_mem(ck_cmdline, system_ram,
259 crash_size, crash_base);
260
261 return parse_crashkernel_simple(ck_cmdline, crash_size, crash_base);
262 }
263
264 /*
265 * That function is the entry point for command line parsing and should be
266 * called from the arch-specific code.
267 */
parse_crashkernel(char * cmdline,unsigned long long system_ram,unsigned long long * crash_size,unsigned long long * crash_base)268 int __init parse_crashkernel(char *cmdline,
269 unsigned long long system_ram,
270 unsigned long long *crash_size,
271 unsigned long long *crash_base)
272 {
273 return __parse_crashkernel(cmdline, system_ram, crash_size, crash_base,
274 "crashkernel=", NULL);
275 }
276
parse_crashkernel_high(char * cmdline,unsigned long long system_ram,unsigned long long * crash_size,unsigned long long * crash_base)277 int __init parse_crashkernel_high(char *cmdline,
278 unsigned long long system_ram,
279 unsigned long long *crash_size,
280 unsigned long long *crash_base)
281 {
282 return __parse_crashkernel(cmdline, system_ram, crash_size, crash_base,
283 "crashkernel=", suffix_tbl[SUFFIX_HIGH]);
284 }
285
parse_crashkernel_low(char * cmdline,unsigned long long system_ram,unsigned long long * crash_size,unsigned long long * crash_base)286 int __init parse_crashkernel_low(char *cmdline,
287 unsigned long long system_ram,
288 unsigned long long *crash_size,
289 unsigned long long *crash_base)
290 {
291 return __parse_crashkernel(cmdline, system_ram, crash_size, crash_base,
292 "crashkernel=", suffix_tbl[SUFFIX_LOW]);
293 }
294
295 /*
296 * Add a dummy early_param handler to mark crashkernel= as a known command line
297 * parameter and suppress incorrect warnings in init/main.c.
298 */
parse_crashkernel_dummy(char * arg)299 static int __init parse_crashkernel_dummy(char *arg)
300 {
301 return 0;
302 }
303 early_param("crashkernel", parse_crashkernel_dummy);
304
append_elf_note(Elf_Word * buf,char * name,unsigned int type,void * data,size_t data_len)305 Elf_Word *append_elf_note(Elf_Word *buf, char *name, unsigned int type,
306 void *data, size_t data_len)
307 {
308 struct elf_note *note = (struct elf_note *)buf;
309
310 note->n_namesz = strlen(name) + 1;
311 note->n_descsz = data_len;
312 note->n_type = type;
313 buf += DIV_ROUND_UP(sizeof(*note), sizeof(Elf_Word));
314 memcpy(buf, name, note->n_namesz);
315 buf += DIV_ROUND_UP(note->n_namesz, sizeof(Elf_Word));
316 memcpy(buf, data, data_len);
317 buf += DIV_ROUND_UP(data_len, sizeof(Elf_Word));
318
319 return buf;
320 }
321
final_note(Elf_Word * buf)322 void final_note(Elf_Word *buf)
323 {
324 memset(buf, 0, sizeof(struct elf_note));
325 }
326
update_vmcoreinfo_note(void)327 static void update_vmcoreinfo_note(void)
328 {
329 u32 *buf = vmcoreinfo_note;
330
331 if (!vmcoreinfo_size)
332 return;
333 buf = append_elf_note(buf, VMCOREINFO_NOTE_NAME, 0, vmcoreinfo_data,
334 vmcoreinfo_size);
335 final_note(buf);
336 }
337
crash_update_vmcoreinfo_safecopy(void * ptr)338 void crash_update_vmcoreinfo_safecopy(void *ptr)
339 {
340 if (ptr)
341 memcpy(ptr, vmcoreinfo_data, vmcoreinfo_size);
342
343 vmcoreinfo_data_safecopy = ptr;
344 }
345
crash_save_vmcoreinfo(void)346 void crash_save_vmcoreinfo(void)
347 {
348 if (!vmcoreinfo_note)
349 return;
350
351 /* Use the safe copy to generate vmcoreinfo note if have */
352 if (vmcoreinfo_data_safecopy)
353 vmcoreinfo_data = vmcoreinfo_data_safecopy;
354
355 vmcoreinfo_append_str("CRASHTIME=%lld\n", ktime_get_real_seconds());
356 update_vmcoreinfo_note();
357 }
358
vmcoreinfo_append_str(const char * fmt,...)359 void vmcoreinfo_append_str(const char *fmt, ...)
360 {
361 va_list args;
362 char buf[0x50];
363 size_t r;
364
365 va_start(args, fmt);
366 r = vscnprintf(buf, sizeof(buf), fmt, args);
367 va_end(args);
368
369 r = min(r, (size_t)VMCOREINFO_BYTES - vmcoreinfo_size);
370
371 memcpy(&vmcoreinfo_data[vmcoreinfo_size], buf, r);
372
373 vmcoreinfo_size += r;
374 }
375
376 /*
377 * provide an empty default implementation here -- architecture
378 * code may override this
379 */
arch_crash_save_vmcoreinfo(void)380 void __weak arch_crash_save_vmcoreinfo(void)
381 {}
382
paddr_vmcoreinfo_note(void)383 phys_addr_t __weak paddr_vmcoreinfo_note(void)
384 {
385 return __pa(vmcoreinfo_note);
386 }
387 EXPORT_SYMBOL(paddr_vmcoreinfo_note);
388
crash_save_vmcoreinfo_init(void)389 static int __init crash_save_vmcoreinfo_init(void)
390 {
391 vmcoreinfo_data = (unsigned char *)get_zeroed_page(GFP_KERNEL);
392 if (!vmcoreinfo_data) {
393 pr_warn("Memory allocation for vmcoreinfo_data failed\n");
394 return -ENOMEM;
395 }
396
397 vmcoreinfo_note = alloc_pages_exact(VMCOREINFO_NOTE_SIZE,
398 GFP_KERNEL | __GFP_ZERO);
399 if (!vmcoreinfo_note) {
400 free_page((unsigned long)vmcoreinfo_data);
401 vmcoreinfo_data = NULL;
402 pr_warn("Memory allocation for vmcoreinfo_note failed\n");
403 return -ENOMEM;
404 }
405
406 VMCOREINFO_OSRELEASE(init_uts_ns.name.release);
407 VMCOREINFO_BUILD_ID();
408 VMCOREINFO_PAGESIZE(PAGE_SIZE);
409
410 VMCOREINFO_SYMBOL(init_uts_ns);
411 VMCOREINFO_OFFSET(uts_namespace, name);
412 VMCOREINFO_SYMBOL(node_online_map);
413 #ifdef CONFIG_MMU
414 VMCOREINFO_SYMBOL_ARRAY(swapper_pg_dir);
415 #endif
416 VMCOREINFO_SYMBOL(_stext);
417 VMCOREINFO_SYMBOL(vmap_area_list);
418
419 #ifndef CONFIG_NUMA
420 VMCOREINFO_SYMBOL(mem_map);
421 VMCOREINFO_SYMBOL(contig_page_data);
422 #endif
423 #ifdef CONFIG_SPARSEMEM
424 VMCOREINFO_SYMBOL_ARRAY(mem_section);
425 VMCOREINFO_LENGTH(mem_section, NR_SECTION_ROOTS);
426 VMCOREINFO_STRUCT_SIZE(mem_section);
427 VMCOREINFO_OFFSET(mem_section, section_mem_map);
428 VMCOREINFO_NUMBER(SECTION_SIZE_BITS);
429 VMCOREINFO_NUMBER(MAX_PHYSMEM_BITS);
430 #endif
431 VMCOREINFO_STRUCT_SIZE(page);
432 VMCOREINFO_STRUCT_SIZE(pglist_data);
433 VMCOREINFO_STRUCT_SIZE(zone);
434 VMCOREINFO_STRUCT_SIZE(free_area);
435 VMCOREINFO_STRUCT_SIZE(list_head);
436 VMCOREINFO_SIZE(nodemask_t);
437 VMCOREINFO_OFFSET(page, flags);
438 VMCOREINFO_OFFSET(page, _refcount);
439 VMCOREINFO_OFFSET(page, mapping);
440 VMCOREINFO_OFFSET(page, lru);
441 VMCOREINFO_OFFSET(page, _mapcount);
442 VMCOREINFO_OFFSET(page, private);
443 VMCOREINFO_OFFSET(page, compound_dtor);
444 VMCOREINFO_OFFSET(page, compound_order);
445 VMCOREINFO_OFFSET(page, compound_head);
446 VMCOREINFO_OFFSET(pglist_data, node_zones);
447 VMCOREINFO_OFFSET(pglist_data, nr_zones);
448 #ifdef CONFIG_FLATMEM
449 VMCOREINFO_OFFSET(pglist_data, node_mem_map);
450 #endif
451 VMCOREINFO_OFFSET(pglist_data, node_start_pfn);
452 VMCOREINFO_OFFSET(pglist_data, node_spanned_pages);
453 VMCOREINFO_OFFSET(pglist_data, node_id);
454 VMCOREINFO_OFFSET(zone, free_area);
455 VMCOREINFO_OFFSET(zone, vm_stat);
456 VMCOREINFO_OFFSET(zone, spanned_pages);
457 VMCOREINFO_OFFSET(free_area, free_list);
458 VMCOREINFO_OFFSET(list_head, next);
459 VMCOREINFO_OFFSET(list_head, prev);
460 VMCOREINFO_OFFSET(vmap_area, va_start);
461 VMCOREINFO_OFFSET(vmap_area, list);
462 VMCOREINFO_LENGTH(zone.free_area, MAX_ORDER);
463 log_buf_vmcoreinfo_setup();
464 VMCOREINFO_LENGTH(free_area.free_list, MIGRATE_TYPES);
465 VMCOREINFO_NUMBER(NR_FREE_PAGES);
466 VMCOREINFO_NUMBER(PG_lru);
467 VMCOREINFO_NUMBER(PG_private);
468 VMCOREINFO_NUMBER(PG_swapcache);
469 VMCOREINFO_NUMBER(PG_swapbacked);
470 VMCOREINFO_NUMBER(PG_slab);
471 #ifdef CONFIG_MEMORY_FAILURE
472 VMCOREINFO_NUMBER(PG_hwpoison);
473 #endif
474 VMCOREINFO_NUMBER(PG_head_mask);
475 #define PAGE_BUDDY_MAPCOUNT_VALUE (~PG_buddy)
476 VMCOREINFO_NUMBER(PAGE_BUDDY_MAPCOUNT_VALUE);
477 #ifdef CONFIG_HUGETLB_PAGE
478 VMCOREINFO_NUMBER(HUGETLB_PAGE_DTOR);
479 #define PAGE_OFFLINE_MAPCOUNT_VALUE (~PG_offline)
480 VMCOREINFO_NUMBER(PAGE_OFFLINE_MAPCOUNT_VALUE);
481 #endif
482
483 arch_crash_save_vmcoreinfo();
484 update_vmcoreinfo_note();
485
486 return 0;
487 }
488
489 subsys_initcall(crash_save_vmcoreinfo_init);
490