]> Pileus Git - ~andy/linux/blob - tools/perf/util/symbol.c
perf symbols: Prevent the use of kcore if the kernel has moved
[~andy/linux] / tools / perf / util / symbol.c
1 #include <dirent.h>
2 #include <errno.h>
3 #include <stdlib.h>
4 #include <stdio.h>
5 #include <string.h>
6 #include <sys/types.h>
7 #include <sys/stat.h>
8 #include <sys/param.h>
9 #include <fcntl.h>
10 #include <unistd.h>
11 #include <inttypes.h>
12 #include "build-id.h"
13 #include "util.h"
14 #include "debug.h"
15 #include "machine.h"
16 #include "symbol.h"
17 #include "strlist.h"
18
19 #include <elf.h>
20 #include <limits.h>
21 #include <symbol/kallsyms.h>
22 #include <sys/utsname.h>
23
24 static int dso__load_kernel_sym(struct dso *dso, struct map *map,
25                                 symbol_filter_t filter);
26 static int dso__load_guest_kernel_sym(struct dso *dso, struct map *map,
27                         symbol_filter_t filter);
28 int vmlinux_path__nr_entries;
29 char **vmlinux_path;
30
31 struct symbol_conf symbol_conf = {
32         .use_modules      = true,
33         .try_vmlinux_path = true,
34         .annotate_src     = true,
35         .demangle         = true,
36         .symfs            = "",
37 };
38
39 static enum dso_binary_type binary_type_symtab[] = {
40         DSO_BINARY_TYPE__KALLSYMS,
41         DSO_BINARY_TYPE__GUEST_KALLSYMS,
42         DSO_BINARY_TYPE__JAVA_JIT,
43         DSO_BINARY_TYPE__DEBUGLINK,
44         DSO_BINARY_TYPE__BUILD_ID_CACHE,
45         DSO_BINARY_TYPE__FEDORA_DEBUGINFO,
46         DSO_BINARY_TYPE__UBUNTU_DEBUGINFO,
47         DSO_BINARY_TYPE__BUILDID_DEBUGINFO,
48         DSO_BINARY_TYPE__SYSTEM_PATH_DSO,
49         DSO_BINARY_TYPE__GUEST_KMODULE,
50         DSO_BINARY_TYPE__SYSTEM_PATH_KMODULE,
51         DSO_BINARY_TYPE__OPENEMBEDDED_DEBUGINFO,
52         DSO_BINARY_TYPE__NOT_FOUND,
53 };
54
55 #define DSO_BINARY_TYPE__SYMTAB_CNT ARRAY_SIZE(binary_type_symtab)
56
57 bool symbol_type__is_a(char symbol_type, enum map_type map_type)
58 {
59         symbol_type = toupper(symbol_type);
60
61         switch (map_type) {
62         case MAP__FUNCTION:
63                 return symbol_type == 'T' || symbol_type == 'W';
64         case MAP__VARIABLE:
65                 return symbol_type == 'D';
66         default:
67                 return false;
68         }
69 }
70
71 static int prefix_underscores_count(const char *str)
72 {
73         const char *tail = str;
74
75         while (*tail == '_')
76                 tail++;
77
78         return tail - str;
79 }
80
81 #define SYMBOL_A 0
82 #define SYMBOL_B 1
83
84 static int choose_best_symbol(struct symbol *syma, struct symbol *symb)
85 {
86         s64 a;
87         s64 b;
88         size_t na, nb;
89
90         /* Prefer a symbol with non zero length */
91         a = syma->end - syma->start;
92         b = symb->end - symb->start;
93         if ((b == 0) && (a > 0))
94                 return SYMBOL_A;
95         else if ((a == 0) && (b > 0))
96                 return SYMBOL_B;
97
98         /* Prefer a non weak symbol over a weak one */
99         a = syma->binding == STB_WEAK;
100         b = symb->binding == STB_WEAK;
101         if (b && !a)
102                 return SYMBOL_A;
103         if (a && !b)
104                 return SYMBOL_B;
105
106         /* Prefer a global symbol over a non global one */
107         a = syma->binding == STB_GLOBAL;
108         b = symb->binding == STB_GLOBAL;
109         if (a && !b)
110                 return SYMBOL_A;
111         if (b && !a)
112                 return SYMBOL_B;
113
114         /* Prefer a symbol with less underscores */
115         a = prefix_underscores_count(syma->name);
116         b = prefix_underscores_count(symb->name);
117         if (b > a)
118                 return SYMBOL_A;
119         else if (a > b)
120                 return SYMBOL_B;
121
122         /* Choose the symbol with the longest name */
123         na = strlen(syma->name);
124         nb = strlen(symb->name);
125         if (na > nb)
126                 return SYMBOL_A;
127         else if (na < nb)
128                 return SYMBOL_B;
129
130         /* Avoid "SyS" kernel syscall aliases */
131         if (na >= 3 && !strncmp(syma->name, "SyS", 3))
132                 return SYMBOL_B;
133         if (na >= 10 && !strncmp(syma->name, "compat_SyS", 10))
134                 return SYMBOL_B;
135
136         return SYMBOL_A;
137 }
138
139 void symbols__fixup_duplicate(struct rb_root *symbols)
140 {
141         struct rb_node *nd;
142         struct symbol *curr, *next;
143
144         nd = rb_first(symbols);
145
146         while (nd) {
147                 curr = rb_entry(nd, struct symbol, rb_node);
148 again:
149                 nd = rb_next(&curr->rb_node);
150                 next = rb_entry(nd, struct symbol, rb_node);
151
152                 if (!nd)
153                         break;
154
155                 if (curr->start != next->start)
156                         continue;
157
158                 if (choose_best_symbol(curr, next) == SYMBOL_A) {
159                         rb_erase(&next->rb_node, symbols);
160                         symbol__delete(next);
161                         goto again;
162                 } else {
163                         nd = rb_next(&curr->rb_node);
164                         rb_erase(&curr->rb_node, symbols);
165                         symbol__delete(curr);
166                 }
167         }
168 }
169
170 void symbols__fixup_end(struct rb_root *symbols)
171 {
172         struct rb_node *nd, *prevnd = rb_first(symbols);
173         struct symbol *curr, *prev;
174
175         if (prevnd == NULL)
176                 return;
177
178         curr = rb_entry(prevnd, struct symbol, rb_node);
179
180         for (nd = rb_next(prevnd); nd; nd = rb_next(nd)) {
181                 prev = curr;
182                 curr = rb_entry(nd, struct symbol, rb_node);
183
184                 if (prev->end == prev->start && prev->end != curr->start)
185                         prev->end = curr->start - 1;
186         }
187
188         /* Last entry */
189         if (curr->end == curr->start)
190                 curr->end = roundup(curr->start, 4096);
191 }
192
193 void __map_groups__fixup_end(struct map_groups *mg, enum map_type type)
194 {
195         struct map *prev, *curr;
196         struct rb_node *nd, *prevnd = rb_first(&mg->maps[type]);
197
198         if (prevnd == NULL)
199                 return;
200
201         curr = rb_entry(prevnd, struct map, rb_node);
202
203         for (nd = rb_next(prevnd); nd; nd = rb_next(nd)) {
204                 prev = curr;
205                 curr = rb_entry(nd, struct map, rb_node);
206                 prev->end = curr->start - 1;
207         }
208
209         /*
210          * We still haven't the actual symbols, so guess the
211          * last map final address.
212          */
213         curr->end = ~0ULL;
214 }
215
216 struct symbol *symbol__new(u64 start, u64 len, u8 binding, const char *name)
217 {
218         size_t namelen = strlen(name) + 1;
219         struct symbol *sym = calloc(1, (symbol_conf.priv_size +
220                                         sizeof(*sym) + namelen));
221         if (sym == NULL)
222                 return NULL;
223
224         if (symbol_conf.priv_size)
225                 sym = ((void *)sym) + symbol_conf.priv_size;
226
227         sym->start   = start;
228         sym->end     = len ? start + len - 1 : start;
229         sym->binding = binding;
230         sym->namelen = namelen - 1;
231
232         pr_debug4("%s: %s %#" PRIx64 "-%#" PRIx64 "\n",
233                   __func__, name, start, sym->end);
234         memcpy(sym->name, name, namelen);
235
236         return sym;
237 }
238
239 void symbol__delete(struct symbol *sym)
240 {
241         free(((void *)sym) - symbol_conf.priv_size);
242 }
243
244 size_t symbol__fprintf(struct symbol *sym, FILE *fp)
245 {
246         return fprintf(fp, " %" PRIx64 "-%" PRIx64 " %c %s\n",
247                        sym->start, sym->end,
248                        sym->binding == STB_GLOBAL ? 'g' :
249                        sym->binding == STB_LOCAL  ? 'l' : 'w',
250                        sym->name);
251 }
252
253 size_t symbol__fprintf_symname_offs(const struct symbol *sym,
254                                     const struct addr_location *al, FILE *fp)
255 {
256         unsigned long offset;
257         size_t length;
258
259         if (sym && sym->name) {
260                 length = fprintf(fp, "%s", sym->name);
261                 if (al) {
262                         if (al->addr < sym->end)
263                                 offset = al->addr - sym->start;
264                         else
265                                 offset = al->addr - al->map->start - sym->start;
266                         length += fprintf(fp, "+0x%lx", offset);
267                 }
268                 return length;
269         } else
270                 return fprintf(fp, "[unknown]");
271 }
272
273 size_t symbol__fprintf_symname(const struct symbol *sym, FILE *fp)
274 {
275         return symbol__fprintf_symname_offs(sym, NULL, fp);
276 }
277
278 void symbols__delete(struct rb_root *symbols)
279 {
280         struct symbol *pos;
281         struct rb_node *next = rb_first(symbols);
282
283         while (next) {
284                 pos = rb_entry(next, struct symbol, rb_node);
285                 next = rb_next(&pos->rb_node);
286                 rb_erase(&pos->rb_node, symbols);
287                 symbol__delete(pos);
288         }
289 }
290
291 void symbols__insert(struct rb_root *symbols, struct symbol *sym)
292 {
293         struct rb_node **p = &symbols->rb_node;
294         struct rb_node *parent = NULL;
295         const u64 ip = sym->start;
296         struct symbol *s;
297
298         while (*p != NULL) {
299                 parent = *p;
300                 s = rb_entry(parent, struct symbol, rb_node);
301                 if (ip < s->start)
302                         p = &(*p)->rb_left;
303                 else
304                         p = &(*p)->rb_right;
305         }
306         rb_link_node(&sym->rb_node, parent, p);
307         rb_insert_color(&sym->rb_node, symbols);
308 }
309
310 static struct symbol *symbols__find(struct rb_root *symbols, u64 ip)
311 {
312         struct rb_node *n;
313
314         if (symbols == NULL)
315                 return NULL;
316
317         n = symbols->rb_node;
318
319         while (n) {
320                 struct symbol *s = rb_entry(n, struct symbol, rb_node);
321
322                 if (ip < s->start)
323                         n = n->rb_left;
324                 else if (ip > s->end)
325                         n = n->rb_right;
326                 else
327                         return s;
328         }
329
330         return NULL;
331 }
332
333 static struct symbol *symbols__first(struct rb_root *symbols)
334 {
335         struct rb_node *n = rb_first(symbols);
336
337         if (n)
338                 return rb_entry(n, struct symbol, rb_node);
339
340         return NULL;
341 }
342
343 struct symbol_name_rb_node {
344         struct rb_node  rb_node;
345         struct symbol   sym;
346 };
347
348 static void symbols__insert_by_name(struct rb_root *symbols, struct symbol *sym)
349 {
350         struct rb_node **p = &symbols->rb_node;
351         struct rb_node *parent = NULL;
352         struct symbol_name_rb_node *symn, *s;
353
354         symn = container_of(sym, struct symbol_name_rb_node, sym);
355
356         while (*p != NULL) {
357                 parent = *p;
358                 s = rb_entry(parent, struct symbol_name_rb_node, rb_node);
359                 if (strcmp(sym->name, s->sym.name) < 0)
360                         p = &(*p)->rb_left;
361                 else
362                         p = &(*p)->rb_right;
363         }
364         rb_link_node(&symn->rb_node, parent, p);
365         rb_insert_color(&symn->rb_node, symbols);
366 }
367
368 static void symbols__sort_by_name(struct rb_root *symbols,
369                                   struct rb_root *source)
370 {
371         struct rb_node *nd;
372
373         for (nd = rb_first(source); nd; nd = rb_next(nd)) {
374                 struct symbol *pos = rb_entry(nd, struct symbol, rb_node);
375                 symbols__insert_by_name(symbols, pos);
376         }
377 }
378
379 static struct symbol *symbols__find_by_name(struct rb_root *symbols,
380                                             const char *name)
381 {
382         struct rb_node *n;
383
384         if (symbols == NULL)
385                 return NULL;
386
387         n = symbols->rb_node;
388
389         while (n) {
390                 struct symbol_name_rb_node *s;
391                 int cmp;
392
393                 s = rb_entry(n, struct symbol_name_rb_node, rb_node);
394                 cmp = strcmp(name, s->sym.name);
395
396                 if (cmp < 0)
397                         n = n->rb_left;
398                 else if (cmp > 0)
399                         n = n->rb_right;
400                 else
401                         return &s->sym;
402         }
403
404         return NULL;
405 }
406
407 struct symbol *dso__find_symbol(struct dso *dso,
408                                 enum map_type type, u64 addr)
409 {
410         return symbols__find(&dso->symbols[type], addr);
411 }
412
413 struct symbol *dso__first_symbol(struct dso *dso, enum map_type type)
414 {
415         return symbols__first(&dso->symbols[type]);
416 }
417
418 struct symbol *dso__find_symbol_by_name(struct dso *dso, enum map_type type,
419                                         const char *name)
420 {
421         return symbols__find_by_name(&dso->symbol_names[type], name);
422 }
423
424 void dso__sort_by_name(struct dso *dso, enum map_type type)
425 {
426         dso__set_sorted_by_name(dso, type);
427         return symbols__sort_by_name(&dso->symbol_names[type],
428                                      &dso->symbols[type]);
429 }
430
431 size_t dso__fprintf_symbols_by_name(struct dso *dso,
432                                     enum map_type type, FILE *fp)
433 {
434         size_t ret = 0;
435         struct rb_node *nd;
436         struct symbol_name_rb_node *pos;
437
438         for (nd = rb_first(&dso->symbol_names[type]); nd; nd = rb_next(nd)) {
439                 pos = rb_entry(nd, struct symbol_name_rb_node, rb_node);
440                 fprintf(fp, "%s\n", pos->sym.name);
441         }
442
443         return ret;
444 }
445
446 int modules__parse(const char *filename, void *arg,
447                    int (*process_module)(void *arg, const char *name,
448                                          u64 start))
449 {
450         char *line = NULL;
451         size_t n;
452         FILE *file;
453         int err = 0;
454
455         file = fopen(filename, "r");
456         if (file == NULL)
457                 return -1;
458
459         while (1) {
460                 char name[PATH_MAX];
461                 u64 start;
462                 char *sep;
463                 ssize_t line_len;
464
465                 line_len = getline(&line, &n, file);
466                 if (line_len < 0) {
467                         if (feof(file))
468                                 break;
469                         err = -1;
470                         goto out;
471                 }
472
473                 if (!line) {
474                         err = -1;
475                         goto out;
476                 }
477
478                 line[--line_len] = '\0'; /* \n */
479
480                 sep = strrchr(line, 'x');
481                 if (sep == NULL)
482                         continue;
483
484                 hex2u64(sep + 1, &start);
485
486                 sep = strchr(line, ' ');
487                 if (sep == NULL)
488                         continue;
489
490                 *sep = '\0';
491
492                 scnprintf(name, sizeof(name), "[%s]", line);
493
494                 err = process_module(arg, name, start);
495                 if (err)
496                         break;
497         }
498 out:
499         free(line);
500         fclose(file);
501         return err;
502 }
503
504 struct process_kallsyms_args {
505         struct map *map;
506         struct dso *dso;
507 };
508
509 bool symbol__is_idle(struct symbol *sym)
510 {
511         const char * const idle_symbols[] = {
512                 "cpu_idle",
513                 "intel_idle",
514                 "default_idle",
515                 "native_safe_halt",
516                 "enter_idle",
517                 "exit_idle",
518                 "mwait_idle",
519                 "mwait_idle_with_hints",
520                 "poll_idle",
521                 "ppc64_runlatch_off",
522                 "pseries_dedicated_idle_sleep",
523                 NULL
524         };
525
526         int i;
527
528         if (!sym)
529                 return false;
530
531         for (i = 0; idle_symbols[i]; i++) {
532                 if (!strcmp(idle_symbols[i], sym->name))
533                         return true;
534         }
535
536         return false;
537 }
538
539 static int map__process_kallsym_symbol(void *arg, const char *name,
540                                        char type, u64 start)
541 {
542         struct symbol *sym;
543         struct process_kallsyms_args *a = arg;
544         struct rb_root *root = &a->dso->symbols[a->map->type];
545
546         if (!symbol_type__is_a(type, a->map->type))
547                 return 0;
548
549         /*
550          * module symbols are not sorted so we add all
551          * symbols, setting length to 0, and rely on
552          * symbols__fixup_end() to fix it up.
553          */
554         sym = symbol__new(start, 0, kallsyms2elf_type(type), name);
555         if (sym == NULL)
556                 return -ENOMEM;
557         /*
558          * We will pass the symbols to the filter later, in
559          * map__split_kallsyms, when we have split the maps per module
560          */
561         symbols__insert(root, sym);
562
563         return 0;
564 }
565
566 /*
567  * Loads the function entries in /proc/kallsyms into kernel_map->dso,
568  * so that we can in the next step set the symbol ->end address and then
569  * call kernel_maps__split_kallsyms.
570  */
571 static int dso__load_all_kallsyms(struct dso *dso, const char *filename,
572                                   struct map *map)
573 {
574         struct process_kallsyms_args args = { .map = map, .dso = dso, };
575         return kallsyms__parse(filename, &args, map__process_kallsym_symbol);
576 }
577
578 static int dso__split_kallsyms_for_kcore(struct dso *dso, struct map *map,
579                                          symbol_filter_t filter)
580 {
581         struct map_groups *kmaps = map__kmap(map)->kmaps;
582         struct map *curr_map;
583         struct symbol *pos;
584         int count = 0, moved = 0;
585         struct rb_root *root = &dso->symbols[map->type];
586         struct rb_node *next = rb_first(root);
587
588         while (next) {
589                 char *module;
590
591                 pos = rb_entry(next, struct symbol, rb_node);
592                 next = rb_next(&pos->rb_node);
593
594                 module = strchr(pos->name, '\t');
595                 if (module)
596                         *module = '\0';
597
598                 curr_map = map_groups__find(kmaps, map->type, pos->start);
599
600                 if (!curr_map || (filter && filter(curr_map, pos))) {
601                         rb_erase(&pos->rb_node, root);
602                         symbol__delete(pos);
603                 } else {
604                         pos->start -= curr_map->start - curr_map->pgoff;
605                         if (pos->end)
606                                 pos->end -= curr_map->start - curr_map->pgoff;
607                         if (curr_map != map) {
608                                 rb_erase(&pos->rb_node, root);
609                                 symbols__insert(
610                                         &curr_map->dso->symbols[curr_map->type],
611                                         pos);
612                                 ++moved;
613                         } else {
614                                 ++count;
615                         }
616                 }
617         }
618
619         /* Symbols have been adjusted */
620         dso->adjust_symbols = 1;
621
622         return count + moved;
623 }
624
625 /*
626  * Split the symbols into maps, making sure there are no overlaps, i.e. the
627  * kernel range is broken in several maps, named [kernel].N, as we don't have
628  * the original ELF section names vmlinux have.
629  */
630 static int dso__split_kallsyms(struct dso *dso, struct map *map,
631                                symbol_filter_t filter)
632 {
633         struct map_groups *kmaps = map__kmap(map)->kmaps;
634         struct machine *machine = kmaps->machine;
635         struct map *curr_map = map;
636         struct symbol *pos;
637         int count = 0, moved = 0;       
638         struct rb_root *root = &dso->symbols[map->type];
639         struct rb_node *next = rb_first(root);
640         int kernel_range = 0;
641
642         while (next) {
643                 char *module;
644
645                 pos = rb_entry(next, struct symbol, rb_node);
646                 next = rb_next(&pos->rb_node);
647
648                 module = strchr(pos->name, '\t');
649                 if (module) {
650                         if (!symbol_conf.use_modules)
651                                 goto discard_symbol;
652
653                         *module++ = '\0';
654
655                         if (strcmp(curr_map->dso->short_name, module)) {
656                                 if (curr_map != map &&
657                                     dso->kernel == DSO_TYPE_GUEST_KERNEL &&
658                                     machine__is_default_guest(machine)) {
659                                         /*
660                                          * We assume all symbols of a module are
661                                          * continuous in * kallsyms, so curr_map
662                                          * points to a module and all its
663                                          * symbols are in its kmap. Mark it as
664                                          * loaded.
665                                          */
666                                         dso__set_loaded(curr_map->dso,
667                                                         curr_map->type);
668                                 }
669
670                                 curr_map = map_groups__find_by_name(kmaps,
671                                                         map->type, module);
672                                 if (curr_map == NULL) {
673                                         pr_debug("%s/proc/{kallsyms,modules} "
674                                                  "inconsistency while looking "
675                                                  "for \"%s\" module!\n",
676                                                  machine->root_dir, module);
677                                         curr_map = map;
678                                         goto discard_symbol;
679                                 }
680
681                                 if (curr_map->dso->loaded &&
682                                     !machine__is_default_guest(machine))
683                                         goto discard_symbol;
684                         }
685                         /*
686                          * So that we look just like we get from .ko files,
687                          * i.e. not prelinked, relative to map->start.
688                          */
689                         pos->start = curr_map->map_ip(curr_map, pos->start);
690                         pos->end   = curr_map->map_ip(curr_map, pos->end);
691                 } else if (curr_map != map) {
692                         char dso_name[PATH_MAX];
693                         struct dso *ndso;
694
695                         if (count == 0) {
696                                 curr_map = map;
697                                 goto filter_symbol;
698                         }
699
700                         if (dso->kernel == DSO_TYPE_GUEST_KERNEL)
701                                 snprintf(dso_name, sizeof(dso_name),
702                                         "[guest.kernel].%d",
703                                         kernel_range++);
704                         else
705                                 snprintf(dso_name, sizeof(dso_name),
706                                         "[kernel].%d",
707                                         kernel_range++);
708
709                         ndso = dso__new(dso_name);
710                         if (ndso == NULL)
711                                 return -1;
712
713                         ndso->kernel = dso->kernel;
714
715                         curr_map = map__new2(pos->start, ndso, map->type);
716                         if (curr_map == NULL) {
717                                 dso__delete(ndso);
718                                 return -1;
719                         }
720
721                         curr_map->map_ip = curr_map->unmap_ip = identity__map_ip;
722                         map_groups__insert(kmaps, curr_map);
723                         ++kernel_range;
724                 }
725 filter_symbol:
726                 if (filter && filter(curr_map, pos)) {
727 discard_symbol:         rb_erase(&pos->rb_node, root);
728                         symbol__delete(pos);
729                 } else {
730                         if (curr_map != map) {
731                                 rb_erase(&pos->rb_node, root);
732                                 symbols__insert(&curr_map->dso->symbols[curr_map->type], pos);
733                                 ++moved;
734                         } else
735                                 ++count;
736                 }
737         }
738
739         if (curr_map != map &&
740             dso->kernel == DSO_TYPE_GUEST_KERNEL &&
741             machine__is_default_guest(kmaps->machine)) {
742                 dso__set_loaded(curr_map->dso, curr_map->type);
743         }
744
745         return count + moved;
746 }
747
748 bool symbol__restricted_filename(const char *filename,
749                                  const char *restricted_filename)
750 {
751         bool restricted = false;
752
753         if (symbol_conf.kptr_restrict) {
754                 char *r = realpath(filename, NULL);
755
756                 if (r != NULL) {
757                         restricted = strcmp(r, restricted_filename) == 0;
758                         free(r);
759                         return restricted;
760                 }
761         }
762
763         return restricted;
764 }
765
766 struct module_info {
767         struct rb_node rb_node;
768         char *name;
769         u64 start;
770 };
771
772 static void add_module(struct module_info *mi, struct rb_root *modules)
773 {
774         struct rb_node **p = &modules->rb_node;
775         struct rb_node *parent = NULL;
776         struct module_info *m;
777
778         while (*p != NULL) {
779                 parent = *p;
780                 m = rb_entry(parent, struct module_info, rb_node);
781                 if (strcmp(mi->name, m->name) < 0)
782                         p = &(*p)->rb_left;
783                 else
784                         p = &(*p)->rb_right;
785         }
786         rb_link_node(&mi->rb_node, parent, p);
787         rb_insert_color(&mi->rb_node, modules);
788 }
789
790 static void delete_modules(struct rb_root *modules)
791 {
792         struct module_info *mi;
793         struct rb_node *next = rb_first(modules);
794
795         while (next) {
796                 mi = rb_entry(next, struct module_info, rb_node);
797                 next = rb_next(&mi->rb_node);
798                 rb_erase(&mi->rb_node, modules);
799                 zfree(&mi->name);
800                 free(mi);
801         }
802 }
803
804 static struct module_info *find_module(const char *name,
805                                        struct rb_root *modules)
806 {
807         struct rb_node *n = modules->rb_node;
808
809         while (n) {
810                 struct module_info *m;
811                 int cmp;
812
813                 m = rb_entry(n, struct module_info, rb_node);
814                 cmp = strcmp(name, m->name);
815                 if (cmp < 0)
816                         n = n->rb_left;
817                 else if (cmp > 0)
818                         n = n->rb_right;
819                 else
820                         return m;
821         }
822
823         return NULL;
824 }
825
826 static int __read_proc_modules(void *arg, const char *name, u64 start)
827 {
828         struct rb_root *modules = arg;
829         struct module_info *mi;
830
831         mi = zalloc(sizeof(struct module_info));
832         if (!mi)
833                 return -ENOMEM;
834
835         mi->name = strdup(name);
836         mi->start = start;
837
838         if (!mi->name) {
839                 free(mi);
840                 return -ENOMEM;
841         }
842
843         add_module(mi, modules);
844
845         return 0;
846 }
847
848 static int read_proc_modules(const char *filename, struct rb_root *modules)
849 {
850         if (symbol__restricted_filename(filename, "/proc/modules"))
851                 return -1;
852
853         if (modules__parse(filename, modules, __read_proc_modules)) {
854                 delete_modules(modules);
855                 return -1;
856         }
857
858         return 0;
859 }
860
861 int compare_proc_modules(const char *from, const char *to)
862 {
863         struct rb_root from_modules = RB_ROOT;
864         struct rb_root to_modules = RB_ROOT;
865         struct rb_node *from_node, *to_node;
866         struct module_info *from_m, *to_m;
867         int ret = -1;
868
869         if (read_proc_modules(from, &from_modules))
870                 return -1;
871
872         if (read_proc_modules(to, &to_modules))
873                 goto out_delete_from;
874
875         from_node = rb_first(&from_modules);
876         to_node = rb_first(&to_modules);
877         while (from_node) {
878                 if (!to_node)
879                         break;
880
881                 from_m = rb_entry(from_node, struct module_info, rb_node);
882                 to_m = rb_entry(to_node, struct module_info, rb_node);
883
884                 if (from_m->start != to_m->start ||
885                     strcmp(from_m->name, to_m->name))
886                         break;
887
888                 from_node = rb_next(from_node);
889                 to_node = rb_next(to_node);
890         }
891
892         if (!from_node && !to_node)
893                 ret = 0;
894
895         delete_modules(&to_modules);
896 out_delete_from:
897         delete_modules(&from_modules);
898
899         return ret;
900 }
901
902 static int do_validate_kcore_modules(const char *filename, struct map *map,
903                                   struct map_groups *kmaps)
904 {
905         struct rb_root modules = RB_ROOT;
906         struct map *old_map;
907         int err;
908
909         err = read_proc_modules(filename, &modules);
910         if (err)
911                 return err;
912
913         old_map = map_groups__first(kmaps, map->type);
914         while (old_map) {
915                 struct map *next = map_groups__next(old_map);
916                 struct module_info *mi;
917
918                 if (old_map == map || old_map->start == map->start) {
919                         /* The kernel map */
920                         old_map = next;
921                         continue;
922                 }
923
924                 /* Module must be in memory at the same address */
925                 mi = find_module(old_map->dso->short_name, &modules);
926                 if (!mi || mi->start != old_map->start) {
927                         err = -EINVAL;
928                         goto out;
929                 }
930
931                 old_map = next;
932         }
933 out:
934         delete_modules(&modules);
935         return err;
936 }
937
938 /*
939  * If kallsyms is referenced by name then we look for filename in the same
940  * directory.
941  */
942 static bool filename_from_kallsyms_filename(char *filename,
943                                             const char *base_name,
944                                             const char *kallsyms_filename)
945 {
946         char *name;
947
948         strcpy(filename, kallsyms_filename);
949         name = strrchr(filename, '/');
950         if (!name)
951                 return false;
952
953         name += 1;
954
955         if (!strcmp(name, "kallsyms")) {
956                 strcpy(name, base_name);
957                 return true;
958         }
959
960         return false;
961 }
962
963 static int validate_kcore_modules(const char *kallsyms_filename,
964                                   struct map *map)
965 {
966         struct map_groups *kmaps = map__kmap(map)->kmaps;
967         char modules_filename[PATH_MAX];
968
969         if (!filename_from_kallsyms_filename(modules_filename, "modules",
970                                              kallsyms_filename))
971                 return -EINVAL;
972
973         if (do_validate_kcore_modules(modules_filename, map, kmaps))
974                 return -EINVAL;
975
976         return 0;
977 }
978
979 static int validate_kcore_addresses(const char *kallsyms_filename,
980                                     struct map *map)
981 {
982         struct kmap *kmap = map__kmap(map);
983
984         if (kmap->ref_reloc_sym && kmap->ref_reloc_sym->name) {
985                 u64 start;
986
987                 start = kallsyms__get_function_start(kallsyms_filename,
988                                                      kmap->ref_reloc_sym->name);
989                 if (start != kmap->ref_reloc_sym->addr)
990                         return -EINVAL;
991         }
992
993         return validate_kcore_modules(kallsyms_filename, map);
994 }
995
996 struct kcore_mapfn_data {
997         struct dso *dso;
998         enum map_type type;
999         struct list_head maps;
1000 };
1001
1002 static int kcore_mapfn(u64 start, u64 len, u64 pgoff, void *data)
1003 {
1004         struct kcore_mapfn_data *md = data;
1005         struct map *map;
1006
1007         map = map__new2(start, md->dso, md->type);
1008         if (map == NULL)
1009                 return -ENOMEM;
1010
1011         map->end = map->start + len;
1012         map->pgoff = pgoff;
1013
1014         list_add(&map->node, &md->maps);
1015
1016         return 0;
1017 }
1018
1019 static int dso__load_kcore(struct dso *dso, struct map *map,
1020                            const char *kallsyms_filename)
1021 {
1022         struct map_groups *kmaps = map__kmap(map)->kmaps;
1023         struct machine *machine = kmaps->machine;
1024         struct kcore_mapfn_data md;
1025         struct map *old_map, *new_map, *replacement_map = NULL;
1026         bool is_64_bit;
1027         int err, fd;
1028         char kcore_filename[PATH_MAX];
1029         struct symbol *sym;
1030
1031         /* This function requires that the map is the kernel map */
1032         if (map != machine->vmlinux_maps[map->type])
1033                 return -EINVAL;
1034
1035         if (!filename_from_kallsyms_filename(kcore_filename, "kcore",
1036                                              kallsyms_filename))
1037                 return -EINVAL;
1038
1039         /* Modules and kernel must be present at their original addresses */
1040         if (validate_kcore_addresses(kallsyms_filename, map))
1041                 return -EINVAL;
1042
1043         md.dso = dso;
1044         md.type = map->type;
1045         INIT_LIST_HEAD(&md.maps);
1046
1047         fd = open(kcore_filename, O_RDONLY);
1048         if (fd < 0)
1049                 return -EINVAL;
1050
1051         /* Read new maps into temporary lists */
1052         err = file__read_maps(fd, md.type == MAP__FUNCTION, kcore_mapfn, &md,
1053                               &is_64_bit);
1054         if (err)
1055                 goto out_err;
1056
1057         if (list_empty(&md.maps)) {
1058                 err = -EINVAL;
1059                 goto out_err;
1060         }
1061
1062         /* Remove old maps */
1063         old_map = map_groups__first(kmaps, map->type);
1064         while (old_map) {
1065                 struct map *next = map_groups__next(old_map);
1066
1067                 if (old_map != map)
1068                         map_groups__remove(kmaps, old_map);
1069                 old_map = next;
1070         }
1071
1072         /* Find the kernel map using the first symbol */
1073         sym = dso__first_symbol(dso, map->type);
1074         list_for_each_entry(new_map, &md.maps, node) {
1075                 if (sym && sym->start >= new_map->start &&
1076                     sym->start < new_map->end) {
1077                         replacement_map = new_map;
1078                         break;
1079                 }
1080         }
1081
1082         if (!replacement_map)
1083                 replacement_map = list_entry(md.maps.next, struct map, node);
1084
1085         /* Add new maps */
1086         while (!list_empty(&md.maps)) {
1087                 new_map = list_entry(md.maps.next, struct map, node);
1088                 list_del(&new_map->node);
1089                 if (new_map == replacement_map) {
1090                         map->start      = new_map->start;
1091                         map->end        = new_map->end;
1092                         map->pgoff      = new_map->pgoff;
1093                         map->map_ip     = new_map->map_ip;
1094                         map->unmap_ip   = new_map->unmap_ip;
1095                         map__delete(new_map);
1096                         /* Ensure maps are correctly ordered */
1097                         map_groups__remove(kmaps, map);
1098                         map_groups__insert(kmaps, map);
1099                 } else {
1100                         map_groups__insert(kmaps, new_map);
1101                 }
1102         }
1103
1104         /*
1105          * Set the data type and long name so that kcore can be read via
1106          * dso__data_read_addr().
1107          */
1108         if (dso->kernel == DSO_TYPE_GUEST_KERNEL)
1109                 dso->binary_type = DSO_BINARY_TYPE__GUEST_KCORE;
1110         else
1111                 dso->binary_type = DSO_BINARY_TYPE__KCORE;
1112         dso__set_long_name(dso, strdup(kcore_filename), true);
1113
1114         close(fd);
1115
1116         if (map->type == MAP__FUNCTION)
1117                 pr_debug("Using %s for kernel object code\n", kcore_filename);
1118         else
1119                 pr_debug("Using %s for kernel data\n", kcore_filename);
1120
1121         return 0;
1122
1123 out_err:
1124         while (!list_empty(&md.maps)) {
1125                 map = list_entry(md.maps.next, struct map, node);
1126                 list_del(&map->node);
1127                 map__delete(map);
1128         }
1129         close(fd);
1130         return -EINVAL;
1131 }
1132
1133 int dso__load_kallsyms(struct dso *dso, const char *filename,
1134                        struct map *map, symbol_filter_t filter)
1135 {
1136         if (symbol__restricted_filename(filename, "/proc/kallsyms"))
1137                 return -1;
1138
1139         if (dso__load_all_kallsyms(dso, filename, map) < 0)
1140                 return -1;
1141
1142         symbols__fixup_duplicate(&dso->symbols[map->type]);
1143         symbols__fixup_end(&dso->symbols[map->type]);
1144
1145         if (dso->kernel == DSO_TYPE_GUEST_KERNEL)
1146                 dso->symtab_type = DSO_BINARY_TYPE__GUEST_KALLSYMS;
1147         else
1148                 dso->symtab_type = DSO_BINARY_TYPE__KALLSYMS;
1149
1150         if (!dso__load_kcore(dso, map, filename))
1151                 return dso__split_kallsyms_for_kcore(dso, map, filter);
1152         else
1153                 return dso__split_kallsyms(dso, map, filter);
1154 }
1155
1156 static int dso__load_perf_map(struct dso *dso, struct map *map,
1157                               symbol_filter_t filter)
1158 {
1159         char *line = NULL;
1160         size_t n;
1161         FILE *file;
1162         int nr_syms = 0;
1163
1164         file = fopen(dso->long_name, "r");
1165         if (file == NULL)
1166                 goto out_failure;
1167
1168         while (!feof(file)) {
1169                 u64 start, size;
1170                 struct symbol *sym;
1171                 int line_len, len;
1172
1173                 line_len = getline(&line, &n, file);
1174                 if (line_len < 0)
1175                         break;
1176
1177                 if (!line)
1178                         goto out_failure;
1179
1180                 line[--line_len] = '\0'; /* \n */
1181
1182                 len = hex2u64(line, &start);
1183
1184                 len++;
1185                 if (len + 2 >= line_len)
1186                         continue;
1187
1188                 len += hex2u64(line + len, &size);
1189
1190                 len++;
1191                 if (len + 2 >= line_len)
1192                         continue;
1193
1194                 sym = symbol__new(start, size, STB_GLOBAL, line + len);
1195
1196                 if (sym == NULL)
1197                         goto out_delete_line;
1198
1199                 if (filter && filter(map, sym))
1200                         symbol__delete(sym);
1201                 else {
1202                         symbols__insert(&dso->symbols[map->type], sym);
1203                         nr_syms++;
1204                 }
1205         }
1206
1207         free(line);
1208         fclose(file);
1209
1210         return nr_syms;
1211
1212 out_delete_line:
1213         free(line);
1214 out_failure:
1215         return -1;
1216 }
1217
1218 int dso__load(struct dso *dso, struct map *map, symbol_filter_t filter)
1219 {
1220         char *name;
1221         int ret = -1;
1222         u_int i;
1223         struct machine *machine;
1224         char *root_dir = (char *) "";
1225         int ss_pos = 0;
1226         struct symsrc ss_[2];
1227         struct symsrc *syms_ss = NULL, *runtime_ss = NULL;
1228
1229         dso__set_loaded(dso, map->type);
1230
1231         if (dso->kernel == DSO_TYPE_KERNEL)
1232                 return dso__load_kernel_sym(dso, map, filter);
1233         else if (dso->kernel == DSO_TYPE_GUEST_KERNEL)
1234                 return dso__load_guest_kernel_sym(dso, map, filter);
1235
1236         if (map->groups && map->groups->machine)
1237                 machine = map->groups->machine;
1238         else
1239                 machine = NULL;
1240
1241         dso->adjust_symbols = 0;
1242
1243         if (strncmp(dso->name, "/tmp/perf-", 10) == 0) {
1244                 struct stat st;
1245
1246                 if (lstat(dso->name, &st) < 0)
1247                         return -1;
1248
1249                 if (st.st_uid && (st.st_uid != geteuid())) {
1250                         pr_warning("File %s not owned by current user or root, "
1251                                 "ignoring it.\n", dso->name);
1252                         return -1;
1253                 }
1254
1255                 ret = dso__load_perf_map(dso, map, filter);
1256                 dso->symtab_type = ret > 0 ? DSO_BINARY_TYPE__JAVA_JIT :
1257                                              DSO_BINARY_TYPE__NOT_FOUND;
1258                 return ret;
1259         }
1260
1261         if (machine)
1262                 root_dir = machine->root_dir;
1263
1264         name = malloc(PATH_MAX);
1265         if (!name)
1266                 return -1;
1267
1268         /* Iterate over candidate debug images.
1269          * Keep track of "interesting" ones (those which have a symtab, dynsym,
1270          * and/or opd section) for processing.
1271          */
1272         for (i = 0; i < DSO_BINARY_TYPE__SYMTAB_CNT; i++) {
1273                 struct symsrc *ss = &ss_[ss_pos];
1274                 bool next_slot = false;
1275
1276                 enum dso_binary_type symtab_type = binary_type_symtab[i];
1277
1278                 if (dso__read_binary_type_filename(dso, symtab_type,
1279                                                    root_dir, name, PATH_MAX))
1280                         continue;
1281
1282                 /* Name is now the name of the next image to try */
1283                 if (symsrc__init(ss, dso, name, symtab_type) < 0)
1284                         continue;
1285
1286                 if (!syms_ss && symsrc__has_symtab(ss)) {
1287                         syms_ss = ss;
1288                         next_slot = true;
1289                         if (!dso->symsrc_filename)
1290                                 dso->symsrc_filename = strdup(name);
1291                 }
1292
1293                 if (!runtime_ss && symsrc__possibly_runtime(ss)) {
1294                         runtime_ss = ss;
1295                         next_slot = true;
1296                 }
1297
1298                 if (next_slot) {
1299                         ss_pos++;
1300
1301                         if (syms_ss && runtime_ss)
1302                                 break;
1303                 }
1304
1305         }
1306
1307         if (!runtime_ss && !syms_ss)
1308                 goto out_free;
1309
1310         if (runtime_ss && !syms_ss) {
1311                 syms_ss = runtime_ss;
1312         }
1313
1314         /* We'll have to hope for the best */
1315         if (!runtime_ss && syms_ss)
1316                 runtime_ss = syms_ss;
1317
1318         if (syms_ss) {
1319                 int km;
1320
1321                 km = dso->symtab_type == DSO_BINARY_TYPE__SYSTEM_PATH_KMODULE ||
1322                      dso->symtab_type == DSO_BINARY_TYPE__GUEST_KMODULE;
1323                 ret = dso__load_sym(dso, map, syms_ss, runtime_ss, filter, km);
1324         } else {
1325                 ret = -1;
1326         }
1327
1328         if (ret > 0) {
1329                 int nr_plt;
1330
1331                 nr_plt = dso__synthesize_plt_symbols(dso, runtime_ss, map, filter);
1332                 if (nr_plt > 0)
1333                         ret += nr_plt;
1334         }
1335
1336         for (; ss_pos > 0; ss_pos--)
1337                 symsrc__destroy(&ss_[ss_pos - 1]);
1338 out_free:
1339         free(name);
1340         if (ret < 0 && strstr(dso->name, " (deleted)") != NULL)
1341                 return 0;
1342         return ret;
1343 }
1344
1345 struct map *map_groups__find_by_name(struct map_groups *mg,
1346                                      enum map_type type, const char *name)
1347 {
1348         struct rb_node *nd;
1349
1350         for (nd = rb_first(&mg->maps[type]); nd; nd = rb_next(nd)) {
1351                 struct map *map = rb_entry(nd, struct map, rb_node);
1352
1353                 if (map->dso && strcmp(map->dso->short_name, name) == 0)
1354                         return map;
1355         }
1356
1357         return NULL;
1358 }
1359
1360 int dso__load_vmlinux(struct dso *dso, struct map *map,
1361                       const char *vmlinux, bool vmlinux_allocated,
1362                       symbol_filter_t filter)
1363 {
1364         int err = -1;
1365         struct symsrc ss;
1366         char symfs_vmlinux[PATH_MAX];
1367         enum dso_binary_type symtab_type;
1368
1369         if (vmlinux[0] == '/')
1370                 snprintf(symfs_vmlinux, sizeof(symfs_vmlinux), "%s", vmlinux);
1371         else
1372                 snprintf(symfs_vmlinux, sizeof(symfs_vmlinux), "%s%s",
1373                          symbol_conf.symfs, vmlinux);
1374
1375         if (dso->kernel == DSO_TYPE_GUEST_KERNEL)
1376                 symtab_type = DSO_BINARY_TYPE__GUEST_VMLINUX;
1377         else
1378                 symtab_type = DSO_BINARY_TYPE__VMLINUX;
1379
1380         if (symsrc__init(&ss, dso, symfs_vmlinux, symtab_type))
1381                 return -1;
1382
1383         err = dso__load_sym(dso, map, &ss, &ss, filter, 0);
1384         symsrc__destroy(&ss);
1385
1386         if (err > 0) {
1387                 if (dso->kernel == DSO_TYPE_GUEST_KERNEL)
1388                         dso->binary_type = DSO_BINARY_TYPE__GUEST_VMLINUX;
1389                 else
1390                         dso->binary_type = DSO_BINARY_TYPE__VMLINUX;
1391                 dso__set_long_name(dso, vmlinux, vmlinux_allocated);
1392                 dso__set_loaded(dso, map->type);
1393                 pr_debug("Using %s for symbols\n", symfs_vmlinux);
1394         }
1395
1396         return err;
1397 }
1398
1399 int dso__load_vmlinux_path(struct dso *dso, struct map *map,
1400                            symbol_filter_t filter)
1401 {
1402         int i, err = 0;
1403         char *filename;
1404
1405         pr_debug("Looking at the vmlinux_path (%d entries long)\n",
1406                  vmlinux_path__nr_entries + 1);
1407
1408         filename = dso__build_id_filename(dso, NULL, 0);
1409         if (filename != NULL) {
1410                 err = dso__load_vmlinux(dso, map, filename, true, filter);
1411                 if (err > 0)
1412                         goto out;
1413                 free(filename);
1414         }
1415
1416         for (i = 0; i < vmlinux_path__nr_entries; ++i) {
1417                 err = dso__load_vmlinux(dso, map, vmlinux_path[i], false, filter);
1418                 if (err > 0)
1419                         break;
1420         }
1421 out:
1422         return err;
1423 }
1424
1425 static int find_matching_kcore(struct map *map, char *dir, size_t dir_sz)
1426 {
1427         char kallsyms_filename[PATH_MAX];
1428         struct dirent *dent;
1429         int ret = -1;
1430         DIR *d;
1431
1432         d = opendir(dir);
1433         if (!d)
1434                 return -1;
1435
1436         while (1) {
1437                 dent = readdir(d);
1438                 if (!dent)
1439                         break;
1440                 if (dent->d_type != DT_DIR)
1441                         continue;
1442                 scnprintf(kallsyms_filename, sizeof(kallsyms_filename),
1443                           "%s/%s/kallsyms", dir, dent->d_name);
1444                 if (!validate_kcore_addresses(kallsyms_filename, map)) {
1445                         strlcpy(dir, kallsyms_filename, dir_sz);
1446                         ret = 0;
1447                         break;
1448                 }
1449         }
1450
1451         closedir(d);
1452
1453         return ret;
1454 }
1455
1456 static char *dso__find_kallsyms(struct dso *dso, struct map *map)
1457 {
1458         u8 host_build_id[BUILD_ID_SIZE];
1459         char sbuild_id[BUILD_ID_SIZE * 2 + 1];
1460         bool is_host = false;
1461         char path[PATH_MAX];
1462
1463         if (!dso->has_build_id) {
1464                 /*
1465                  * Last resort, if we don't have a build-id and couldn't find
1466                  * any vmlinux file, try the running kernel kallsyms table.
1467                  */
1468                 goto proc_kallsyms;
1469         }
1470
1471         if (sysfs__read_build_id("/sys/kernel/notes", host_build_id,
1472                                  sizeof(host_build_id)) == 0)
1473                 is_host = dso__build_id_equal(dso, host_build_id);
1474
1475         build_id__sprintf(dso->build_id, sizeof(dso->build_id), sbuild_id);
1476
1477         scnprintf(path, sizeof(path), "%s/[kernel.kcore]/%s", buildid_dir,
1478                   sbuild_id);
1479
1480         /* Use /proc/kallsyms if possible */
1481         if (is_host) {
1482                 DIR *d;
1483                 int fd;
1484
1485                 /* If no cached kcore go with /proc/kallsyms */
1486                 d = opendir(path);
1487                 if (!d)
1488                         goto proc_kallsyms;
1489                 closedir(d);
1490
1491                 /*
1492                  * Do not check the build-id cache, until we know we cannot use
1493                  * /proc/kcore.
1494                  */
1495                 fd = open("/proc/kcore", O_RDONLY);
1496                 if (fd != -1) {
1497                         close(fd);
1498                         /* If module maps match go with /proc/kallsyms */
1499                         if (!validate_kcore_addresses("/proc/kallsyms", map))
1500                                 goto proc_kallsyms;
1501                 }
1502
1503                 /* Find kallsyms in build-id cache with kcore */
1504                 if (!find_matching_kcore(map, path, sizeof(path)))
1505                         return strdup(path);
1506
1507                 goto proc_kallsyms;
1508         }
1509
1510         /* Find kallsyms in build-id cache with kcore */
1511         if (!find_matching_kcore(map, path, sizeof(path)))
1512                 return strdup(path);
1513
1514         scnprintf(path, sizeof(path), "%s/[kernel.kallsyms]/%s",
1515                   buildid_dir, sbuild_id);
1516
1517         if (access(path, F_OK)) {
1518                 pr_err("No kallsyms or vmlinux with build-id %s was found\n",
1519                        sbuild_id);
1520                 return NULL;
1521         }
1522
1523         return strdup(path);
1524
1525 proc_kallsyms:
1526         return strdup("/proc/kallsyms");
1527 }
1528
1529 static int dso__load_kernel_sym(struct dso *dso, struct map *map,
1530                                 symbol_filter_t filter)
1531 {
1532         int err;
1533         const char *kallsyms_filename = NULL;
1534         char *kallsyms_allocated_filename = NULL;
1535         /*
1536          * Step 1: if the user specified a kallsyms or vmlinux filename, use
1537          * it and only it, reporting errors to the user if it cannot be used.
1538          *
1539          * For instance, try to analyse an ARM perf.data file _without_ a
1540          * build-id, or if the user specifies the wrong path to the right
1541          * vmlinux file, obviously we can't fallback to another vmlinux (a
1542          * x86_86 one, on the machine where analysis is being performed, say),
1543          * or worse, /proc/kallsyms.
1544          *
1545          * If the specified file _has_ a build-id and there is a build-id
1546          * section in the perf.data file, we will still do the expected
1547          * validation in dso__load_vmlinux and will bail out if they don't
1548          * match.
1549          */
1550         if (symbol_conf.kallsyms_name != NULL) {
1551                 kallsyms_filename = symbol_conf.kallsyms_name;
1552                 goto do_kallsyms;
1553         }
1554
1555         if (!symbol_conf.ignore_vmlinux && symbol_conf.vmlinux_name != NULL) {
1556                 return dso__load_vmlinux(dso, map, symbol_conf.vmlinux_name,
1557                                          false, filter);
1558         }
1559
1560         if (!symbol_conf.ignore_vmlinux && vmlinux_path != NULL) {
1561                 err = dso__load_vmlinux_path(dso, map, filter);
1562                 if (err > 0)
1563                         return err;
1564         }
1565
1566         /* do not try local files if a symfs was given */
1567         if (symbol_conf.symfs[0] != 0)
1568                 return -1;
1569
1570         kallsyms_allocated_filename = dso__find_kallsyms(dso, map);
1571         if (!kallsyms_allocated_filename)
1572                 return -1;
1573
1574         kallsyms_filename = kallsyms_allocated_filename;
1575
1576 do_kallsyms:
1577         err = dso__load_kallsyms(dso, kallsyms_filename, map, filter);
1578         if (err > 0)
1579                 pr_debug("Using %s for symbols\n", kallsyms_filename);
1580         free(kallsyms_allocated_filename);
1581
1582         if (err > 0 && !dso__is_kcore(dso)) {
1583                 dso__set_long_name(dso, "[kernel.kallsyms]", false);
1584                 map__fixup_start(map);
1585                 map__fixup_end(map);
1586         }
1587
1588         return err;
1589 }
1590
1591 static int dso__load_guest_kernel_sym(struct dso *dso, struct map *map,
1592                                       symbol_filter_t filter)
1593 {
1594         int err;
1595         const char *kallsyms_filename = NULL;
1596         struct machine *machine;
1597         char path[PATH_MAX];
1598
1599         if (!map->groups) {
1600                 pr_debug("Guest kernel map hasn't the point to groups\n");
1601                 return -1;
1602         }
1603         machine = map->groups->machine;
1604
1605         if (machine__is_default_guest(machine)) {
1606                 /*
1607                  * if the user specified a vmlinux filename, use it and only
1608                  * it, reporting errors to the user if it cannot be used.
1609                  * Or use file guest_kallsyms inputted by user on commandline
1610                  */
1611                 if (symbol_conf.default_guest_vmlinux_name != NULL) {
1612                         err = dso__load_vmlinux(dso, map,
1613                                                 symbol_conf.default_guest_vmlinux_name,
1614                                                 false, filter);
1615                         return err;
1616                 }
1617
1618                 kallsyms_filename = symbol_conf.default_guest_kallsyms;
1619                 if (!kallsyms_filename)
1620                         return -1;
1621         } else {
1622                 sprintf(path, "%s/proc/kallsyms", machine->root_dir);
1623                 kallsyms_filename = path;
1624         }
1625
1626         err = dso__load_kallsyms(dso, kallsyms_filename, map, filter);
1627         if (err > 0)
1628                 pr_debug("Using %s for symbols\n", kallsyms_filename);
1629         if (err > 0 && !dso__is_kcore(dso)) {
1630                 machine__mmap_name(machine, path, sizeof(path));
1631                 dso__set_long_name(dso, strdup(path), true);
1632                 map__fixup_start(map);
1633                 map__fixup_end(map);
1634         }
1635
1636         return err;
1637 }
1638
1639 static void vmlinux_path__exit(void)
1640 {
1641         while (--vmlinux_path__nr_entries >= 0)
1642                 zfree(&vmlinux_path[vmlinux_path__nr_entries]);
1643
1644         zfree(&vmlinux_path);
1645 }
1646
1647 static int vmlinux_path__init(void)
1648 {
1649         struct utsname uts;
1650         char bf[PATH_MAX];
1651
1652         vmlinux_path = malloc(sizeof(char *) * 5);
1653         if (vmlinux_path == NULL)
1654                 return -1;
1655
1656         vmlinux_path[vmlinux_path__nr_entries] = strdup("vmlinux");
1657         if (vmlinux_path[vmlinux_path__nr_entries] == NULL)
1658                 goto out_fail;
1659         ++vmlinux_path__nr_entries;
1660         vmlinux_path[vmlinux_path__nr_entries] = strdup("/boot/vmlinux");
1661         if (vmlinux_path[vmlinux_path__nr_entries] == NULL)
1662                 goto out_fail;
1663         ++vmlinux_path__nr_entries;
1664
1665         /* only try running kernel version if no symfs was given */
1666         if (symbol_conf.symfs[0] != 0)
1667                 return 0;
1668
1669         if (uname(&uts) < 0)
1670                 return -1;
1671
1672         snprintf(bf, sizeof(bf), "/boot/vmlinux-%s", uts.release);
1673         vmlinux_path[vmlinux_path__nr_entries] = strdup(bf);
1674         if (vmlinux_path[vmlinux_path__nr_entries] == NULL)
1675                 goto out_fail;
1676         ++vmlinux_path__nr_entries;
1677         snprintf(bf, sizeof(bf), "/lib/modules/%s/build/vmlinux", uts.release);
1678         vmlinux_path[vmlinux_path__nr_entries] = strdup(bf);
1679         if (vmlinux_path[vmlinux_path__nr_entries] == NULL)
1680                 goto out_fail;
1681         ++vmlinux_path__nr_entries;
1682         snprintf(bf, sizeof(bf), "/usr/lib/debug/lib/modules/%s/vmlinux",
1683                  uts.release);
1684         vmlinux_path[vmlinux_path__nr_entries] = strdup(bf);
1685         if (vmlinux_path[vmlinux_path__nr_entries] == NULL)
1686                 goto out_fail;
1687         ++vmlinux_path__nr_entries;
1688
1689         return 0;
1690
1691 out_fail:
1692         vmlinux_path__exit();
1693         return -1;
1694 }
1695
1696 int setup_list(struct strlist **list, const char *list_str,
1697                       const char *list_name)
1698 {
1699         if (list_str == NULL)
1700                 return 0;
1701
1702         *list = strlist__new(true, list_str);
1703         if (!*list) {
1704                 pr_err("problems parsing %s list\n", list_name);
1705                 return -1;
1706         }
1707         return 0;
1708 }
1709
1710 static bool symbol__read_kptr_restrict(void)
1711 {
1712         bool value = false;
1713
1714         if (geteuid() != 0) {
1715                 FILE *fp = fopen("/proc/sys/kernel/kptr_restrict", "r");
1716                 if (fp != NULL) {
1717                         char line[8];
1718
1719                         if (fgets(line, sizeof(line), fp) != NULL)
1720                                 value = atoi(line) != 0;
1721
1722                         fclose(fp);
1723                 }
1724         }
1725
1726         return value;
1727 }
1728
1729 int symbol__init(void)
1730 {
1731         const char *symfs;
1732
1733         if (symbol_conf.initialized)
1734                 return 0;
1735
1736         symbol_conf.priv_size = PERF_ALIGN(symbol_conf.priv_size, sizeof(u64));
1737
1738         symbol__elf_init();
1739
1740         if (symbol_conf.sort_by_name)
1741                 symbol_conf.priv_size += (sizeof(struct symbol_name_rb_node) -
1742                                           sizeof(struct symbol));
1743
1744         if (symbol_conf.try_vmlinux_path && vmlinux_path__init() < 0)
1745                 return -1;
1746
1747         if (symbol_conf.field_sep && *symbol_conf.field_sep == '.') {
1748                 pr_err("'.' is the only non valid --field-separator argument\n");
1749                 return -1;
1750         }
1751
1752         if (setup_list(&symbol_conf.dso_list,
1753                        symbol_conf.dso_list_str, "dso") < 0)
1754                 return -1;
1755
1756         if (setup_list(&symbol_conf.comm_list,
1757                        symbol_conf.comm_list_str, "comm") < 0)
1758                 goto out_free_dso_list;
1759
1760         if (setup_list(&symbol_conf.sym_list,
1761                        symbol_conf.sym_list_str, "symbol") < 0)
1762                 goto out_free_comm_list;
1763
1764         /*
1765          * A path to symbols of "/" is identical to ""
1766          * reset here for simplicity.
1767          */
1768         symfs = realpath(symbol_conf.symfs, NULL);
1769         if (symfs == NULL)
1770                 symfs = symbol_conf.symfs;
1771         if (strcmp(symfs, "/") == 0)
1772                 symbol_conf.symfs = "";
1773         if (symfs != symbol_conf.symfs)
1774                 free((void *)symfs);
1775
1776         symbol_conf.kptr_restrict = symbol__read_kptr_restrict();
1777
1778         symbol_conf.initialized = true;
1779         return 0;
1780
1781 out_free_comm_list:
1782         strlist__delete(symbol_conf.comm_list);
1783 out_free_dso_list:
1784         strlist__delete(symbol_conf.dso_list);
1785         return -1;
1786 }
1787
1788 void symbol__exit(void)
1789 {
1790         if (!symbol_conf.initialized)
1791                 return;
1792         strlist__delete(symbol_conf.sym_list);
1793         strlist__delete(symbol_conf.dso_list);
1794         strlist__delete(symbol_conf.comm_list);
1795         vmlinux_path__exit();
1796         symbol_conf.sym_list = symbol_conf.dso_list = symbol_conf.comm_list = NULL;
1797         symbol_conf.initialized = false;
1798 }