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 #include <linux/sizes.h>
13 
14 #include <asm/page.h>
15 #include <asm/sections.h>
16 
17 #include <crypto/sha1.h>
18 
19 #include "kallsyms_internal.h"
20 
21 /* vmcoreinfo stuff */
22 unsigned char *vmcoreinfo_data;
23 size_t vmcoreinfo_size;
24 u32 *vmcoreinfo_note;
25 
26 /* trusted vmcoreinfo, e.g. we can make a copy in the crash memory */
27 static unsigned char *vmcoreinfo_data_safecopy;
28 
29 /*
30  * parsing the "crashkernel" commandline
31  *
32  * this code is intended to be called from architecture specific code
33  */
34 
35 
36 /*
37  * This function parses command lines in the format
38  *
39  *   crashkernel=ramsize-range:size[,...][@offset]
40  *
41  * The function returns 0 on success and -EINVAL on failure.
42  */
parse_crashkernel_mem(char * cmdline,unsigned long long system_ram,unsigned long long * crash_size,unsigned long long * crash_base)43 static int __init parse_crashkernel_mem(char *cmdline,
44 					unsigned long long system_ram,
45 					unsigned long long *crash_size,
46 					unsigned long long *crash_base)
47 {
48 	char *cur = cmdline, *tmp;
49 	unsigned long long total_mem = system_ram;
50 
51 	/*
52 	 * Firmware sometimes reserves some memory regions for its own use,
53 	 * so the system memory size is less than the actual physical memory
54 	 * size. Work around this by rounding up the total size to 128M,
55 	 * which is enough for most test cases.
56 	 */
57 	total_mem = roundup(total_mem, SZ_128M);
58 
59 	/* for each entry of the comma-separated list */
60 	do {
61 		unsigned long long start, end = ULLONG_MAX, size;
62 
63 		/* get the start of the range */
64 		start = memparse(cur, &tmp);
65 		if (cur == tmp) {
66 			pr_warn("crashkernel: Memory value expected\n");
67 			return -EINVAL;
68 		}
69 		cur = tmp;
70 		if (*cur != '-') {
71 			pr_warn("crashkernel: '-' expected\n");
72 			return -EINVAL;
73 		}
74 		cur++;
75 
76 		/* if no ':' is here, than we read the end */
77 		if (*cur != ':') {
78 			end = memparse(cur, &tmp);
79 			if (cur == tmp) {
80 				pr_warn("crashkernel: Memory value expected\n");
81 				return -EINVAL;
82 			}
83 			cur = tmp;
84 			if (end <= start) {
85 				pr_warn("crashkernel: end <= start\n");
86 				return -EINVAL;
87 			}
88 		}
89 
90 		if (*cur != ':') {
91 			pr_warn("crashkernel: ':' expected\n");
92 			return -EINVAL;
93 		}
94 		cur++;
95 
96 		size = memparse(cur, &tmp);
97 		if (cur == tmp) {
98 			pr_warn("Memory value expected\n");
99 			return -EINVAL;
100 		}
101 		cur = tmp;
102 		if (size >= total_mem) {
103 			pr_warn("crashkernel: invalid size\n");
104 			return -EINVAL;
105 		}
106 
107 		/* match ? */
108 		if (total_mem >= start && total_mem < end) {
109 			*crash_size = size;
110 			break;
111 		}
112 	} while (*cur++ == ',');
113 
114 	if (*crash_size > 0) {
115 		while (*cur && *cur != ' ' && *cur != '@')
116 			cur++;
117 		if (*cur == '@') {
118 			cur++;
119 			*crash_base = memparse(cur, &tmp);
120 			if (cur == tmp) {
121 				pr_warn("Memory value expected after '@'\n");
122 				return -EINVAL;
123 			}
124 		}
125 	} else
126 		pr_info("crashkernel size resulted in zero bytes\n");
127 
128 	return 0;
129 }
130 
131 /*
132  * That function parses "simple" (old) crashkernel command lines like
133  *
134  *	crashkernel=size[@offset]
135  *
136  * It returns 0 on success and -EINVAL on failure.
137  */
parse_crashkernel_simple(char * cmdline,unsigned long long * crash_size,unsigned long long * crash_base)138 static int __init parse_crashkernel_simple(char *cmdline,
139 					   unsigned long long *crash_size,
140 					   unsigned long long *crash_base)
141 {
142 	char *cur = cmdline;
143 
144 	*crash_size = memparse(cmdline, &cur);
145 	if (cmdline == cur) {
146 		pr_warn("crashkernel: memory value expected\n");
147 		return -EINVAL;
148 	}
149 
150 	if (*cur == '@')
151 		*crash_base = memparse(cur+1, &cur);
152 	else if (*cur != ' ' && *cur != '\0') {
153 		pr_warn("crashkernel: unrecognized char: %c\n", *cur);
154 		return -EINVAL;
155 	}
156 
157 	return 0;
158 }
159 
160 #define SUFFIX_HIGH 0
161 #define SUFFIX_LOW  1
162 #define SUFFIX_NULL 2
163 static __initdata char *suffix_tbl[] = {
164 	[SUFFIX_HIGH] = ",high",
165 	[SUFFIX_LOW]  = ",low",
166 	[SUFFIX_NULL] = NULL,
167 };
168 
169 /*
170  * That function parses "suffix"  crashkernel command lines like
171  *
172  *	crashkernel=size,[high|low]
173  *
174  * It returns 0 on success and -EINVAL on failure.
175  */
parse_crashkernel_suffix(char * cmdline,unsigned long long * crash_size,const char * suffix)176 static int __init parse_crashkernel_suffix(char *cmdline,
177 					   unsigned long long	*crash_size,
178 					   const char *suffix)
179 {
180 	char *cur = cmdline;
181 
182 	*crash_size = memparse(cmdline, &cur);
183 	if (cmdline == cur) {
184 		pr_warn("crashkernel: memory value expected\n");
185 		return -EINVAL;
186 	}
187 
188 	/* check with suffix */
189 	if (strncmp(cur, suffix, strlen(suffix))) {
190 		pr_warn("crashkernel: unrecognized char: %c\n", *cur);
191 		return -EINVAL;
192 	}
193 	cur += strlen(suffix);
194 	if (*cur != ' ' && *cur != '\0') {
195 		pr_warn("crashkernel: unrecognized char: %c\n", *cur);
196 		return -EINVAL;
197 	}
198 
199 	return 0;
200 }
201 
get_last_crashkernel(char * cmdline,const char * name,const char * suffix)202 static __init char *get_last_crashkernel(char *cmdline,
203 			     const char *name,
204 			     const char *suffix)
205 {
206 	char *p = cmdline, *ck_cmdline = NULL;
207 
208 	/* find crashkernel and use the last one if there are more */
209 	p = strstr(p, name);
210 	while (p) {
211 		char *end_p = strchr(p, ' ');
212 		char *q;
213 
214 		if (!end_p)
215 			end_p = p + strlen(p);
216 
217 		if (!suffix) {
218 			int i;
219 
220 			/* skip the one with any known suffix */
221 			for (i = 0; suffix_tbl[i]; i++) {
222 				q = end_p - strlen(suffix_tbl[i]);
223 				if (!strncmp(q, suffix_tbl[i],
224 					     strlen(suffix_tbl[i])))
225 					goto next;
226 			}
227 			ck_cmdline = p;
228 		} else {
229 			q = end_p - strlen(suffix);
230 			if (!strncmp(q, suffix, strlen(suffix)))
231 				ck_cmdline = p;
232 		}
233 next:
234 		p = strstr(p+1, name);
235 	}
236 
237 	return ck_cmdline;
238 }
239 
__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)240 static int __init __parse_crashkernel(char *cmdline,
241 			     unsigned long long system_ram,
242 			     unsigned long long *crash_size,
243 			     unsigned long long *crash_base,
244 			     const char *name,
245 			     const char *suffix)
246 {
247 	char	*first_colon, *first_space;
248 	char	*ck_cmdline;
249 
250 	BUG_ON(!crash_size || !crash_base);
251 	*crash_size = 0;
252 	*crash_base = 0;
253 
254 	ck_cmdline = get_last_crashkernel(cmdline, name, suffix);
255 	if (!ck_cmdline)
256 		return -ENOENT;
257 
258 	ck_cmdline += strlen(name);
259 
260 	if (suffix)
261 		return parse_crashkernel_suffix(ck_cmdline, crash_size,
262 				suffix);
263 	/*
264 	 * if the commandline contains a ':', then that's the extended
265 	 * syntax -- if not, it must be the classic syntax
266 	 */
267 	first_colon = strchr(ck_cmdline, ':');
268 	first_space = strchr(ck_cmdline, ' ');
269 	if (first_colon && (!first_space || first_colon < first_space))
270 		return parse_crashkernel_mem(ck_cmdline, system_ram,
271 				crash_size, crash_base);
272 
273 	return parse_crashkernel_simple(ck_cmdline, crash_size, crash_base);
274 }
275 
276 /*
277  * That function is the entry point for command line parsing and should be
278  * called from the arch-specific code.
279  */
parse_crashkernel(char * cmdline,unsigned long long system_ram,unsigned long long * crash_size,unsigned long long * crash_base)280 int __init parse_crashkernel(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=", NULL);
287 }
288 
parse_crashkernel_high(char * cmdline,unsigned long long system_ram,unsigned long long * crash_size,unsigned long long * crash_base)289 int __init parse_crashkernel_high(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_HIGH]);
296 }
297 
parse_crashkernel_low(char * cmdline,unsigned long long system_ram,unsigned long long * crash_size,unsigned long long * crash_base)298 int __init parse_crashkernel_low(char *cmdline,
299 			     unsigned long long system_ram,
300 			     unsigned long long *crash_size,
301 			     unsigned long long *crash_base)
302 {
303 	return __parse_crashkernel(cmdline, system_ram, crash_size, crash_base,
304 				"crashkernel=", suffix_tbl[SUFFIX_LOW]);
305 }
306 
307 /*
308  * Add a dummy early_param handler to mark crashkernel= as a known command line
309  * parameter and suppress incorrect warnings in init/main.c.
310  */
parse_crashkernel_dummy(char * arg)311 static int __init parse_crashkernel_dummy(char *arg)
312 {
313 	return 0;
314 }
315 early_param("crashkernel", parse_crashkernel_dummy);
316 
append_elf_note(Elf_Word * buf,char * name,unsigned int type,void * data,size_t data_len)317 Elf_Word *append_elf_note(Elf_Word *buf, char *name, unsigned int type,
318 			  void *data, size_t data_len)
319 {
320 	struct elf_note *note = (struct elf_note *)buf;
321 
322 	note->n_namesz = strlen(name) + 1;
323 	note->n_descsz = data_len;
324 	note->n_type   = type;
325 	buf += DIV_ROUND_UP(sizeof(*note), sizeof(Elf_Word));
326 	memcpy(buf, name, note->n_namesz);
327 	buf += DIV_ROUND_UP(note->n_namesz, sizeof(Elf_Word));
328 	memcpy(buf, data, data_len);
329 	buf += DIV_ROUND_UP(data_len, sizeof(Elf_Word));
330 
331 	return buf;
332 }
333 
final_note(Elf_Word * buf)334 void final_note(Elf_Word *buf)
335 {
336 	memset(buf, 0, sizeof(struct elf_note));
337 }
338 
update_vmcoreinfo_note(void)339 static void update_vmcoreinfo_note(void)
340 {
341 	u32 *buf = vmcoreinfo_note;
342 
343 	if (!vmcoreinfo_size)
344 		return;
345 	buf = append_elf_note(buf, VMCOREINFO_NOTE_NAME, 0, vmcoreinfo_data,
346 			      vmcoreinfo_size);
347 	final_note(buf);
348 }
349 
crash_update_vmcoreinfo_safecopy(void * ptr)350 void crash_update_vmcoreinfo_safecopy(void *ptr)
351 {
352 	if (ptr)
353 		memcpy(ptr, vmcoreinfo_data, vmcoreinfo_size);
354 
355 	vmcoreinfo_data_safecopy = ptr;
356 }
357 
crash_save_vmcoreinfo(void)358 void crash_save_vmcoreinfo(void)
359 {
360 	if (!vmcoreinfo_note)
361 		return;
362 
363 	/* Use the safe copy to generate vmcoreinfo note if have */
364 	if (vmcoreinfo_data_safecopy)
365 		vmcoreinfo_data = vmcoreinfo_data_safecopy;
366 
367 	vmcoreinfo_append_str("CRASHTIME=%lld\n", ktime_get_real_seconds());
368 	update_vmcoreinfo_note();
369 }
370 
vmcoreinfo_append_str(const char * fmt,...)371 void vmcoreinfo_append_str(const char *fmt, ...)
372 {
373 	va_list args;
374 	char buf[0x50];
375 	size_t r;
376 
377 	va_start(args, fmt);
378 	r = vscnprintf(buf, sizeof(buf), fmt, args);
379 	va_end(args);
380 
381 	r = min(r, (size_t)VMCOREINFO_BYTES - vmcoreinfo_size);
382 
383 	memcpy(&vmcoreinfo_data[vmcoreinfo_size], buf, r);
384 
385 	vmcoreinfo_size += r;
386 }
387 
388 /*
389  * provide an empty default implementation here -- architecture
390  * code may override this
391  */
arch_crash_save_vmcoreinfo(void)392 void __weak arch_crash_save_vmcoreinfo(void)
393 {}
394 
paddr_vmcoreinfo_note(void)395 phys_addr_t __weak paddr_vmcoreinfo_note(void)
396 {
397 	return __pa(vmcoreinfo_note);
398 }
399 EXPORT_SYMBOL(paddr_vmcoreinfo_note);
400 
crash_save_vmcoreinfo_init(void)401 static int __init crash_save_vmcoreinfo_init(void)
402 {
403 	vmcoreinfo_data = (unsigned char *)get_zeroed_page(GFP_KERNEL);
404 	if (!vmcoreinfo_data) {
405 		pr_warn("Memory allocation for vmcoreinfo_data failed\n");
406 		return -ENOMEM;
407 	}
408 
409 	vmcoreinfo_note = alloc_pages_exact(VMCOREINFO_NOTE_SIZE,
410 						GFP_KERNEL | __GFP_ZERO);
411 	if (!vmcoreinfo_note) {
412 		free_page((unsigned long)vmcoreinfo_data);
413 		vmcoreinfo_data = NULL;
414 		pr_warn("Memory allocation for vmcoreinfo_note failed\n");
415 		return -ENOMEM;
416 	}
417 
418 	VMCOREINFO_OSRELEASE(init_uts_ns.name.release);
419 	VMCOREINFO_BUILD_ID();
420 	VMCOREINFO_PAGESIZE(PAGE_SIZE);
421 
422 	VMCOREINFO_SYMBOL(init_uts_ns);
423 	VMCOREINFO_OFFSET(uts_namespace, name);
424 	VMCOREINFO_SYMBOL(node_online_map);
425 #ifdef CONFIG_MMU
426 	VMCOREINFO_SYMBOL_ARRAY(swapper_pg_dir);
427 #endif
428 	VMCOREINFO_SYMBOL(_stext);
429 	VMCOREINFO_SYMBOL(vmap_area_list);
430 
431 #ifndef CONFIG_NUMA
432 	VMCOREINFO_SYMBOL(mem_map);
433 	VMCOREINFO_SYMBOL(contig_page_data);
434 #endif
435 #ifdef CONFIG_SPARSEMEM
436 	VMCOREINFO_SYMBOL_ARRAY(mem_section);
437 	VMCOREINFO_LENGTH(mem_section, NR_SECTION_ROOTS);
438 	VMCOREINFO_STRUCT_SIZE(mem_section);
439 	VMCOREINFO_OFFSET(mem_section, section_mem_map);
440 	VMCOREINFO_NUMBER(SECTION_SIZE_BITS);
441 	VMCOREINFO_NUMBER(MAX_PHYSMEM_BITS);
442 #endif
443 	VMCOREINFO_STRUCT_SIZE(page);
444 	VMCOREINFO_STRUCT_SIZE(pglist_data);
445 	VMCOREINFO_STRUCT_SIZE(zone);
446 	VMCOREINFO_STRUCT_SIZE(free_area);
447 	VMCOREINFO_STRUCT_SIZE(list_head);
448 	VMCOREINFO_SIZE(nodemask_t);
449 	VMCOREINFO_OFFSET(page, flags);
450 	VMCOREINFO_OFFSET(page, _refcount);
451 	VMCOREINFO_OFFSET(page, mapping);
452 	VMCOREINFO_OFFSET(page, lru);
453 	VMCOREINFO_OFFSET(page, _mapcount);
454 	VMCOREINFO_OFFSET(page, private);
455 	VMCOREINFO_OFFSET(page, compound_dtor);
456 	VMCOREINFO_OFFSET(page, compound_order);
457 	VMCOREINFO_OFFSET(page, compound_head);
458 	VMCOREINFO_OFFSET(pglist_data, node_zones);
459 	VMCOREINFO_OFFSET(pglist_data, nr_zones);
460 #ifdef CONFIG_FLATMEM
461 	VMCOREINFO_OFFSET(pglist_data, node_mem_map);
462 #endif
463 	VMCOREINFO_OFFSET(pglist_data, node_start_pfn);
464 	VMCOREINFO_OFFSET(pglist_data, node_spanned_pages);
465 	VMCOREINFO_OFFSET(pglist_data, node_id);
466 	VMCOREINFO_OFFSET(zone, free_area);
467 	VMCOREINFO_OFFSET(zone, vm_stat);
468 	VMCOREINFO_OFFSET(zone, spanned_pages);
469 	VMCOREINFO_OFFSET(free_area, free_list);
470 	VMCOREINFO_OFFSET(list_head, next);
471 	VMCOREINFO_OFFSET(list_head, prev);
472 	VMCOREINFO_OFFSET(vmap_area, va_start);
473 	VMCOREINFO_OFFSET(vmap_area, list);
474 	VMCOREINFO_LENGTH(zone.free_area, MAX_ORDER);
475 	log_buf_vmcoreinfo_setup();
476 	VMCOREINFO_LENGTH(free_area.free_list, MIGRATE_TYPES);
477 	VMCOREINFO_NUMBER(NR_FREE_PAGES);
478 	VMCOREINFO_NUMBER(PG_lru);
479 	VMCOREINFO_NUMBER(PG_private);
480 	VMCOREINFO_NUMBER(PG_swapcache);
481 	VMCOREINFO_NUMBER(PG_swapbacked);
482 	VMCOREINFO_NUMBER(PG_slab);
483 #ifdef CONFIG_MEMORY_FAILURE
484 	VMCOREINFO_NUMBER(PG_hwpoison);
485 #endif
486 	VMCOREINFO_NUMBER(PG_head_mask);
487 #define PAGE_BUDDY_MAPCOUNT_VALUE	(~PG_buddy)
488 	VMCOREINFO_NUMBER(PAGE_BUDDY_MAPCOUNT_VALUE);
489 #ifdef CONFIG_HUGETLB_PAGE
490 	VMCOREINFO_NUMBER(HUGETLB_PAGE_DTOR);
491 #define PAGE_OFFLINE_MAPCOUNT_VALUE	(~PG_offline)
492 	VMCOREINFO_NUMBER(PAGE_OFFLINE_MAPCOUNT_VALUE);
493 #endif
494 
495 #ifdef CONFIG_KALLSYMS
496 	VMCOREINFO_SYMBOL(kallsyms_names);
497 	VMCOREINFO_SYMBOL(kallsyms_num_syms);
498 	VMCOREINFO_SYMBOL(kallsyms_token_table);
499 	VMCOREINFO_SYMBOL(kallsyms_token_index);
500 #ifdef CONFIG_KALLSYMS_BASE_RELATIVE
501 	VMCOREINFO_SYMBOL(kallsyms_offsets);
502 	VMCOREINFO_SYMBOL(kallsyms_relative_base);
503 #else
504 	VMCOREINFO_SYMBOL(kallsyms_addresses);
505 #endif /* CONFIG_KALLSYMS_BASE_RELATIVE */
506 #endif /* CONFIG_KALLSYMS */
507 
508 	arch_crash_save_vmcoreinfo();
509 	update_vmcoreinfo_note();
510 
511 	return 0;
512 }
513 
514 subsys_initcall(crash_save_vmcoreinfo_init);
515