Linux 5.2-rc6
[sfrench/cifs-2.6.git] / kernel / crash_core.c
1 /*
2  * crash.c - kernel crash support code.
3  * Copyright (C) 2002-2004 Eric Biederman  <ebiederm@xmission.com>
4  *
5  * This source code is licensed under the GNU General Public License,
6  * Version 2.  See the file COPYING for more details.
7  */
8
9 #include <linux/crash_core.h>
10 #include <linux/utsname.h>
11 #include <linux/vmalloc.h>
12
13 #include <asm/page.h>
14 #include <asm/sections.h>
15
16 /* vmcoreinfo stuff */
17 unsigned char *vmcoreinfo_data;
18 size_t vmcoreinfo_size;
19 u32 *vmcoreinfo_note;
20
21 /* trusted vmcoreinfo, e.g. we can make a copy in the crash memory */
22 static unsigned char *vmcoreinfo_data_safecopy;
23
24 /*
25  * parsing the "crashkernel" commandline
26  *
27  * this code is intended to be called from architecture specific code
28  */
29
30
31 /*
32  * This function parses command lines in the format
33  *
34  *   crashkernel=ramsize-range:size[,...][@offset]
35  *
36  * The function returns 0 on success and -EINVAL on failure.
37  */
38 static int __init parse_crashkernel_mem(char *cmdline,
39                                         unsigned long long system_ram,
40                                         unsigned long long *crash_size,
41                                         unsigned long long *crash_base)
42 {
43         char *cur = cmdline, *tmp;
44
45         /* for each entry of the comma-separated list */
46         do {
47                 unsigned long long start, end = ULLONG_MAX, size;
48
49                 /* get the start of the range */
50                 start = memparse(cur, &tmp);
51                 if (cur == tmp) {
52                         pr_warn("crashkernel: Memory value expected\n");
53                         return -EINVAL;
54                 }
55                 cur = tmp;
56                 if (*cur != '-') {
57                         pr_warn("crashkernel: '-' expected\n");
58                         return -EINVAL;
59                 }
60                 cur++;
61
62                 /* if no ':' is here, than we read the end */
63                 if (*cur != ':') {
64                         end = memparse(cur, &tmp);
65                         if (cur == tmp) {
66                                 pr_warn("crashkernel: Memory value expected\n");
67                                 return -EINVAL;
68                         }
69                         cur = tmp;
70                         if (end <= start) {
71                                 pr_warn("crashkernel: end <= start\n");
72                                 return -EINVAL;
73                         }
74                 }
75
76                 if (*cur != ':') {
77                         pr_warn("crashkernel: ':' expected\n");
78                         return -EINVAL;
79                 }
80                 cur++;
81
82                 size = memparse(cur, &tmp);
83                 if (cur == tmp) {
84                         pr_warn("Memory value expected\n");
85                         return -EINVAL;
86                 }
87                 cur = tmp;
88                 if (size >= system_ram) {
89                         pr_warn("crashkernel: invalid size\n");
90                         return -EINVAL;
91                 }
92
93                 /* match ? */
94                 if (system_ram >= start && system_ram < end) {
95                         *crash_size = size;
96                         break;
97                 }
98         } while (*cur++ == ',');
99
100         if (*crash_size > 0) {
101                 while (*cur && *cur != ' ' && *cur != '@')
102                         cur++;
103                 if (*cur == '@') {
104                         cur++;
105                         *crash_base = memparse(cur, &tmp);
106                         if (cur == tmp) {
107                                 pr_warn("Memory value expected after '@'\n");
108                                 return -EINVAL;
109                         }
110                 }
111         } else
112                 pr_info("crashkernel size resulted in zero bytes\n");
113
114         return 0;
115 }
116
117 /*
118  * That function parses "simple" (old) crashkernel command lines like
119  *
120  *      crashkernel=size[@offset]
121  *
122  * It returns 0 on success and -EINVAL on failure.
123  */
124 static int __init parse_crashkernel_simple(char *cmdline,
125                                            unsigned long long *crash_size,
126                                            unsigned long long *crash_base)
127 {
128         char *cur = cmdline;
129
130         *crash_size = memparse(cmdline, &cur);
131         if (cmdline == cur) {
132                 pr_warn("crashkernel: memory value expected\n");
133                 return -EINVAL;
134         }
135
136         if (*cur == '@')
137                 *crash_base = memparse(cur+1, &cur);
138         else if (*cur != ' ' && *cur != '\0') {
139                 pr_warn("crashkernel: unrecognized char: %c\n", *cur);
140                 return -EINVAL;
141         }
142
143         return 0;
144 }
145
146 #define SUFFIX_HIGH 0
147 #define SUFFIX_LOW  1
148 #define SUFFIX_NULL 2
149 static __initdata char *suffix_tbl[] = {
150         [SUFFIX_HIGH] = ",high",
151         [SUFFIX_LOW]  = ",low",
152         [SUFFIX_NULL] = NULL,
153 };
154
155 /*
156  * That function parses "suffix"  crashkernel command lines like
157  *
158  *      crashkernel=size,[high|low]
159  *
160  * It returns 0 on success and -EINVAL on failure.
161  */
162 static int __init parse_crashkernel_suffix(char *cmdline,
163                                            unsigned long long   *crash_size,
164                                            const char *suffix)
165 {
166         char *cur = cmdline;
167
168         *crash_size = memparse(cmdline, &cur);
169         if (cmdline == cur) {
170                 pr_warn("crashkernel: memory value expected\n");
171                 return -EINVAL;
172         }
173
174         /* check with suffix */
175         if (strncmp(cur, suffix, strlen(suffix))) {
176                 pr_warn("crashkernel: unrecognized char: %c\n", *cur);
177                 return -EINVAL;
178         }
179         cur += strlen(suffix);
180         if (*cur != ' ' && *cur != '\0') {
181                 pr_warn("crashkernel: unrecognized char: %c\n", *cur);
182                 return -EINVAL;
183         }
184
185         return 0;
186 }
187
188 static __init char *get_last_crashkernel(char *cmdline,
189                              const char *name,
190                              const char *suffix)
191 {
192         char *p = cmdline, *ck_cmdline = NULL;
193
194         /* find crashkernel and use the last one if there are more */
195         p = strstr(p, name);
196         while (p) {
197                 char *end_p = strchr(p, ' ');
198                 char *q;
199
200                 if (!end_p)
201                         end_p = p + strlen(p);
202
203                 if (!suffix) {
204                         int i;
205
206                         /* skip the one with any known suffix */
207                         for (i = 0; suffix_tbl[i]; i++) {
208                                 q = end_p - strlen(suffix_tbl[i]);
209                                 if (!strncmp(q, suffix_tbl[i],
210                                              strlen(suffix_tbl[i])))
211                                         goto next;
212                         }
213                         ck_cmdline = p;
214                 } else {
215                         q = end_p - strlen(suffix);
216                         if (!strncmp(q, suffix, strlen(suffix)))
217                                 ck_cmdline = p;
218                 }
219 next:
220                 p = strstr(p+1, name);
221         }
222
223         if (!ck_cmdline)
224                 return NULL;
225
226         return ck_cmdline;
227 }
228
229 static int __init __parse_crashkernel(char *cmdline,
230                              unsigned long long system_ram,
231                              unsigned long long *crash_size,
232                              unsigned long long *crash_base,
233                              const char *name,
234                              const char *suffix)
235 {
236         char    *first_colon, *first_space;
237         char    *ck_cmdline;
238
239         BUG_ON(!crash_size || !crash_base);
240         *crash_size = 0;
241         *crash_base = 0;
242
243         ck_cmdline = get_last_crashkernel(cmdline, name, suffix);
244
245         if (!ck_cmdline)
246                 return -EINVAL;
247
248         ck_cmdline += strlen(name);
249
250         if (suffix)
251                 return parse_crashkernel_suffix(ck_cmdline, crash_size,
252                                 suffix);
253         /*
254          * if the commandline contains a ':', then that's the extended
255          * syntax -- if not, it must be the classic syntax
256          */
257         first_colon = strchr(ck_cmdline, ':');
258         first_space = strchr(ck_cmdline, ' ');
259         if (first_colon && (!first_space || first_colon < first_space))
260                 return parse_crashkernel_mem(ck_cmdline, system_ram,
261                                 crash_size, crash_base);
262
263         return parse_crashkernel_simple(ck_cmdline, crash_size, crash_base);
264 }
265
266 /*
267  * That function is the entry point for command line parsing and should be
268  * called from the arch-specific code.
269  */
270 int __init parse_crashkernel(char *cmdline,
271                              unsigned long long system_ram,
272                              unsigned long long *crash_size,
273                              unsigned long long *crash_base)
274 {
275         return __parse_crashkernel(cmdline, system_ram, crash_size, crash_base,
276                                         "crashkernel=", NULL);
277 }
278
279 int __init parse_crashkernel_high(char *cmdline,
280                              unsigned long long system_ram,
281                              unsigned long long *crash_size,
282                              unsigned long long *crash_base)
283 {
284         return __parse_crashkernel(cmdline, system_ram, crash_size, crash_base,
285                                 "crashkernel=", suffix_tbl[SUFFIX_HIGH]);
286 }
287
288 int __init parse_crashkernel_low(char *cmdline,
289                              unsigned long long system_ram,
290                              unsigned long long *crash_size,
291                              unsigned long long *crash_base)
292 {
293         return __parse_crashkernel(cmdline, system_ram, crash_size, crash_base,
294                                 "crashkernel=", suffix_tbl[SUFFIX_LOW]);
295 }
296
297 Elf_Word *append_elf_note(Elf_Word *buf, char *name, unsigned int type,
298                           void *data, size_t data_len)
299 {
300         struct elf_note *note = (struct elf_note *)buf;
301
302         note->n_namesz = strlen(name) + 1;
303         note->n_descsz = data_len;
304         note->n_type   = type;
305         buf += DIV_ROUND_UP(sizeof(*note), sizeof(Elf_Word));
306         memcpy(buf, name, note->n_namesz);
307         buf += DIV_ROUND_UP(note->n_namesz, sizeof(Elf_Word));
308         memcpy(buf, data, data_len);
309         buf += DIV_ROUND_UP(data_len, sizeof(Elf_Word));
310
311         return buf;
312 }
313
314 void final_note(Elf_Word *buf)
315 {
316         memset(buf, 0, sizeof(struct elf_note));
317 }
318
319 static void update_vmcoreinfo_note(void)
320 {
321         u32 *buf = vmcoreinfo_note;
322
323         if (!vmcoreinfo_size)
324                 return;
325         buf = append_elf_note(buf, VMCOREINFO_NOTE_NAME, 0, vmcoreinfo_data,
326                               vmcoreinfo_size);
327         final_note(buf);
328 }
329
330 void crash_update_vmcoreinfo_safecopy(void *ptr)
331 {
332         if (ptr)
333                 memcpy(ptr, vmcoreinfo_data, vmcoreinfo_size);
334
335         vmcoreinfo_data_safecopy = ptr;
336 }
337
338 void crash_save_vmcoreinfo(void)
339 {
340         if (!vmcoreinfo_note)
341                 return;
342
343         /* Use the safe copy to generate vmcoreinfo note if have */
344         if (vmcoreinfo_data_safecopy)
345                 vmcoreinfo_data = vmcoreinfo_data_safecopy;
346
347         vmcoreinfo_append_str("CRASHTIME=%lld\n", ktime_get_real_seconds());
348         update_vmcoreinfo_note();
349 }
350
351 void vmcoreinfo_append_str(const char *fmt, ...)
352 {
353         va_list args;
354         char buf[0x50];
355         size_t r;
356
357         va_start(args, fmt);
358         r = vscnprintf(buf, sizeof(buf), fmt, args);
359         va_end(args);
360
361         r = min(r, (size_t)VMCOREINFO_BYTES - vmcoreinfo_size);
362
363         memcpy(&vmcoreinfo_data[vmcoreinfo_size], buf, r);
364
365         vmcoreinfo_size += r;
366 }
367
368 /*
369  * provide an empty default implementation here -- architecture
370  * code may override this
371  */
372 void __weak arch_crash_save_vmcoreinfo(void)
373 {}
374
375 phys_addr_t __weak paddr_vmcoreinfo_note(void)
376 {
377         return __pa(vmcoreinfo_note);
378 }
379 EXPORT_SYMBOL(paddr_vmcoreinfo_note);
380
381 static int __init crash_save_vmcoreinfo_init(void)
382 {
383         vmcoreinfo_data = (unsigned char *)get_zeroed_page(GFP_KERNEL);
384         if (!vmcoreinfo_data) {
385                 pr_warn("Memory allocation for vmcoreinfo_data failed\n");
386                 return -ENOMEM;
387         }
388
389         vmcoreinfo_note = alloc_pages_exact(VMCOREINFO_NOTE_SIZE,
390                                                 GFP_KERNEL | __GFP_ZERO);
391         if (!vmcoreinfo_note) {
392                 free_page((unsigned long)vmcoreinfo_data);
393                 vmcoreinfo_data = NULL;
394                 pr_warn("Memory allocation for vmcoreinfo_note failed\n");
395                 return -ENOMEM;
396         }
397
398         VMCOREINFO_OSRELEASE(init_uts_ns.name.release);
399         VMCOREINFO_PAGESIZE(PAGE_SIZE);
400
401         VMCOREINFO_SYMBOL(init_uts_ns);
402         VMCOREINFO_SYMBOL(node_online_map);
403 #ifdef CONFIG_MMU
404         VMCOREINFO_SYMBOL_ARRAY(swapper_pg_dir);
405 #endif
406         VMCOREINFO_SYMBOL(_stext);
407         VMCOREINFO_SYMBOL(vmap_area_list);
408
409 #ifndef CONFIG_NEED_MULTIPLE_NODES
410         VMCOREINFO_SYMBOL(mem_map);
411         VMCOREINFO_SYMBOL(contig_page_data);
412 #endif
413 #ifdef CONFIG_SPARSEMEM
414         VMCOREINFO_SYMBOL_ARRAY(mem_section);
415         VMCOREINFO_LENGTH(mem_section, NR_SECTION_ROOTS);
416         VMCOREINFO_STRUCT_SIZE(mem_section);
417         VMCOREINFO_OFFSET(mem_section, section_mem_map);
418 #endif
419         VMCOREINFO_STRUCT_SIZE(page);
420         VMCOREINFO_STRUCT_SIZE(pglist_data);
421         VMCOREINFO_STRUCT_SIZE(zone);
422         VMCOREINFO_STRUCT_SIZE(free_area);
423         VMCOREINFO_STRUCT_SIZE(list_head);
424         VMCOREINFO_SIZE(nodemask_t);
425         VMCOREINFO_OFFSET(page, flags);
426         VMCOREINFO_OFFSET(page, _refcount);
427         VMCOREINFO_OFFSET(page, mapping);
428         VMCOREINFO_OFFSET(page, lru);
429         VMCOREINFO_OFFSET(page, _mapcount);
430         VMCOREINFO_OFFSET(page, private);
431         VMCOREINFO_OFFSET(page, compound_dtor);
432         VMCOREINFO_OFFSET(page, compound_order);
433         VMCOREINFO_OFFSET(page, compound_head);
434         VMCOREINFO_OFFSET(pglist_data, node_zones);
435         VMCOREINFO_OFFSET(pglist_data, nr_zones);
436 #ifdef CONFIG_FLAT_NODE_MEM_MAP
437         VMCOREINFO_OFFSET(pglist_data, node_mem_map);
438 #endif
439         VMCOREINFO_OFFSET(pglist_data, node_start_pfn);
440         VMCOREINFO_OFFSET(pglist_data, node_spanned_pages);
441         VMCOREINFO_OFFSET(pglist_data, node_id);
442         VMCOREINFO_OFFSET(zone, free_area);
443         VMCOREINFO_OFFSET(zone, vm_stat);
444         VMCOREINFO_OFFSET(zone, spanned_pages);
445         VMCOREINFO_OFFSET(free_area, free_list);
446         VMCOREINFO_OFFSET(list_head, next);
447         VMCOREINFO_OFFSET(list_head, prev);
448         VMCOREINFO_OFFSET(vmap_area, va_start);
449         VMCOREINFO_OFFSET(vmap_area, list);
450         VMCOREINFO_LENGTH(zone.free_area, MAX_ORDER);
451         log_buf_vmcoreinfo_setup();
452         VMCOREINFO_LENGTH(free_area.free_list, MIGRATE_TYPES);
453         VMCOREINFO_NUMBER(NR_FREE_PAGES);
454         VMCOREINFO_NUMBER(PG_lru);
455         VMCOREINFO_NUMBER(PG_private);
456         VMCOREINFO_NUMBER(PG_swapcache);
457         VMCOREINFO_NUMBER(PG_swapbacked);
458         VMCOREINFO_NUMBER(PG_slab);
459 #ifdef CONFIG_MEMORY_FAILURE
460         VMCOREINFO_NUMBER(PG_hwpoison);
461 #endif
462         VMCOREINFO_NUMBER(PG_head_mask);
463 #define PAGE_BUDDY_MAPCOUNT_VALUE       (~PG_buddy)
464         VMCOREINFO_NUMBER(PAGE_BUDDY_MAPCOUNT_VALUE);
465 #ifdef CONFIG_HUGETLB_PAGE
466         VMCOREINFO_NUMBER(HUGETLB_PAGE_DTOR);
467 #define PAGE_OFFLINE_MAPCOUNT_VALUE     (~PG_offline)
468         VMCOREINFO_NUMBER(PAGE_OFFLINE_MAPCOUNT_VALUE);
469 #endif
470
471         arch_crash_save_vmcoreinfo();
472         update_vmcoreinfo_note();
473
474         return 0;
475 }
476
477 subsys_initcall(crash_save_vmcoreinfo_init);