xref: /openbmc/linux/kernel/crash_core.c (revision 2127c01b)
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  */
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  */
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  */
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 
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 
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  */
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 
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 
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 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 
312 void final_note(Elf_Word *buf)
313 {
314 	memset(buf, 0, sizeof(struct elf_note));
315 }
316 
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 
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 
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 
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  */
370 void __weak arch_crash_save_vmcoreinfo(void)
371 {}
372 
373 phys_addr_t __weak paddr_vmcoreinfo_note(void)
374 {
375 	return __pa(vmcoreinfo_note);
376 }
377 EXPORT_SYMBOL(paddr_vmcoreinfo_note);
378 
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