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  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 */
 15unsigned char *vmcoreinfo_data;
 16size_t vmcoreinfo_size;
 17u32 *vmcoreinfo_note;
 18
 19/* trusted vmcoreinfo, e.g. we can make a copy in the crash memory */
 20static 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 */
 36static 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 */
122static 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
147static __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 */
160static 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
186static __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		}
217next:
218		p = strstr(p+1, name);
219	}
220
221	if (!ck_cmdline)
222		return NULL;
223
224	return ck_cmdline;
225}
226
227static 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 */
268int __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
277int __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
286int __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
295Elf_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
312void final_note(Elf_Word *buf)
313{
314	memset(buf, 0, sizeof(struct elf_note));
315}
316
317static 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
328void 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
336void 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
349void 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 */
370void __weak arch_crash_save_vmcoreinfo(void)
371{}
372
373phys_addr_t __weak paddr_vmcoreinfo_note(void)
374{
375	return __pa(vmcoreinfo_note);
376}
377EXPORT_SYMBOL(paddr_vmcoreinfo_note);
378
379static 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
475subsys_initcall(crash_save_vmcoreinfo_init);