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