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TOMOYO Linux Cross Reference
Linux/tools/perf/util/symbol.c

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  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 <sys/utsname.h>
 22 
 23 #ifndef KSYM_NAME_LEN
 24 #define KSYM_NAME_LEN 256
 25 #endif
 26 
 27 static int dso__load_kernel_sym(struct dso *dso, struct map *map,
 28                                 symbol_filter_t filter);
 29 static int dso__load_guest_kernel_sym(struct dso *dso, struct map *map,
 30                         symbol_filter_t filter);
 31 int vmlinux_path__nr_entries;
 32 char **vmlinux_path;
 33 
 34 struct symbol_conf symbol_conf = {
 35         .exclude_other    = true,
 36         .use_modules      = true,
 37         .try_vmlinux_path = true,
 38         .annotate_src     = true,
 39         .symfs            = "",
 40 };
 41 
 42 static enum dso_binary_type binary_type_symtab[] = {
 43         DSO_BINARY_TYPE__KALLSYMS,
 44         DSO_BINARY_TYPE__GUEST_KALLSYMS,
 45         DSO_BINARY_TYPE__JAVA_JIT,
 46         DSO_BINARY_TYPE__DEBUGLINK,
 47         DSO_BINARY_TYPE__BUILD_ID_CACHE,
 48         DSO_BINARY_TYPE__FEDORA_DEBUGINFO,
 49         DSO_BINARY_TYPE__UBUNTU_DEBUGINFO,
 50         DSO_BINARY_TYPE__BUILDID_DEBUGINFO,
 51         DSO_BINARY_TYPE__SYSTEM_PATH_DSO,
 52         DSO_BINARY_TYPE__GUEST_KMODULE,
 53         DSO_BINARY_TYPE__SYSTEM_PATH_KMODULE,
 54         DSO_BINARY_TYPE__NOT_FOUND,
 55 };
 56 
 57 #define DSO_BINARY_TYPE__SYMTAB_CNT ARRAY_SIZE(binary_type_symtab)
 58 
 59 bool symbol_type__is_a(char symbol_type, enum map_type map_type)
 60 {
 61         symbol_type = toupper(symbol_type);
 62 
 63         switch (map_type) {
 64         case MAP__FUNCTION:
 65                 return symbol_type == 'T' || symbol_type == 'W';
 66         case MAP__VARIABLE:
 67                 return symbol_type == 'D';
 68         default:
 69                 return false;
 70         }
 71 }
 72 
 73 static int prefix_underscores_count(const char *str)
 74 {
 75         const char *tail = str;
 76 
 77         while (*tail == '_')
 78                 tail++;
 79 
 80         return tail - str;
 81 }
 82 
 83 #define SYMBOL_A 0
 84 #define SYMBOL_B 1
 85 
 86 static int choose_best_symbol(struct symbol *syma, struct symbol *symb)
 87 {
 88         s64 a;
 89         s64 b;
 90 
 91         /* Prefer a symbol with non zero length */
 92         a = syma->end - syma->start;
 93         b = symb->end - symb->start;
 94         if ((b == 0) && (a > 0))
 95                 return SYMBOL_A;
 96         else if ((a == 0) && (b > 0))
 97                 return SYMBOL_B;
 98 
 99         /* Prefer a non weak symbol over a weak one */
100         a = syma->binding == STB_WEAK;
101         b = symb->binding == STB_WEAK;
102         if (b && !a)
103                 return SYMBOL_A;
104         if (a && !b)
105                 return SYMBOL_B;
106 
107         /* Prefer a global symbol over a non global one */
108         a = syma->binding == STB_GLOBAL;
109         b = symb->binding == STB_GLOBAL;
110         if (a && !b)
111                 return SYMBOL_A;
112         if (b && !a)
113                 return SYMBOL_B;
114 
115         /* Prefer a symbol with less underscores */
116         a = prefix_underscores_count(syma->name);
117         b = prefix_underscores_count(symb->name);
118         if (b > a)
119                 return SYMBOL_A;
120         else if (a > b)
121                 return SYMBOL_B;
122 
123         /* If all else fails, choose the symbol with the longest name */
124         if (strlen(syma->name) >= strlen(symb->name))
125                 return SYMBOL_A;
126         else
127                 return SYMBOL_B;
128 }
129 
130 void symbols__fixup_duplicate(struct rb_root *symbols)
131 {
132         struct rb_node *nd;
133         struct symbol *curr, *next;
134 
135         nd = rb_first(symbols);
136 
137         while (nd) {
138                 curr = rb_entry(nd, struct symbol, rb_node);
139 again:
140                 nd = rb_next(&curr->rb_node);
141                 next = rb_entry(nd, struct symbol, rb_node);
142 
143                 if (!nd)
144                         break;
145 
146                 if (curr->start != next->start)
147                         continue;
148 
149                 if (choose_best_symbol(curr, next) == SYMBOL_A) {
150                         rb_erase(&next->rb_node, symbols);
151                         goto again;
152                 } else {
153                         nd = rb_next(&curr->rb_node);
154                         rb_erase(&curr->rb_node, symbols);
155                 }
156         }
157 }
158 
159 void symbols__fixup_end(struct rb_root *symbols)
160 {
161         struct rb_node *nd, *prevnd = rb_first(symbols);
162         struct symbol *curr, *prev;
163 
164         if (prevnd == NULL)
165                 return;
166 
167         curr = rb_entry(prevnd, struct symbol, rb_node);
168 
169         for (nd = rb_next(prevnd); nd; nd = rb_next(nd)) {
170                 prev = curr;
171                 curr = rb_entry(nd, struct symbol, rb_node);
172 
173                 if (prev->end == prev->start && prev->end != curr->start)
174                         prev->end = curr->start - 1;
175         }
176 
177         /* Last entry */
178         if (curr->end == curr->start)
179                 curr->end = roundup(curr->start, 4096);
180 }
181 
182 void __map_groups__fixup_end(struct map_groups *mg, enum map_type type)
183 {
184         struct map *prev, *curr;
185         struct rb_node *nd, *prevnd = rb_first(&mg->maps[type]);
186 
187         if (prevnd == NULL)
188                 return;
189 
190         curr = rb_entry(prevnd, struct map, rb_node);
191 
192         for (nd = rb_next(prevnd); nd; nd = rb_next(nd)) {
193                 prev = curr;
194                 curr = rb_entry(nd, struct map, rb_node);
195                 prev->end = curr->start - 1;
196         }
197 
198         /*
199          * We still haven't the actual symbols, so guess the
200          * last map final address.
201          */
202         curr->end = ~0ULL;
203 }
204 
205 struct symbol *symbol__new(u64 start, u64 len, u8 binding, const char *name)
206 {
207         size_t namelen = strlen(name) + 1;
208         struct symbol *sym = calloc(1, (symbol_conf.priv_size +
209                                         sizeof(*sym) + namelen));
210         if (sym == NULL)
211                 return NULL;
212 
213         if (symbol_conf.priv_size)
214                 sym = ((void *)sym) + symbol_conf.priv_size;
215 
216         sym->start   = start;
217         sym->end     = len ? start + len - 1 : start;
218         sym->binding = binding;
219         sym->namelen = namelen - 1;
220 
221         pr_debug4("%s: %s %#" PRIx64 "-%#" PRIx64 "\n",
222                   __func__, name, start, sym->end);
223         memcpy(sym->name, name, namelen);
224 
225         return sym;
226 }
227 
228 void symbol__delete(struct symbol *sym)
229 {
230         free(((void *)sym) - symbol_conf.priv_size);
231 }
232 
233 size_t symbol__fprintf(struct symbol *sym, FILE *fp)
234 {
235         return fprintf(fp, " %" PRIx64 "-%" PRIx64 " %c %s\n",
236                        sym->start, sym->end,
237                        sym->binding == STB_GLOBAL ? 'g' :
238                        sym->binding == STB_LOCAL  ? 'l' : 'w',
239                        sym->name);
240 }
241 
242 size_t symbol__fprintf_symname_offs(const struct symbol *sym,
243                                     const struct addr_location *al, FILE *fp)
244 {
245         unsigned long offset;
246         size_t length;
247 
248         if (sym && sym->name) {
249                 length = fprintf(fp, "%s", sym->name);
250                 if (al) {
251                         offset = al->addr - sym->start;
252                         length += fprintf(fp, "+0x%lx", offset);
253                 }
254                 return length;
255         } else
256                 return fprintf(fp, "[unknown]");
257 }
258 
259 size_t symbol__fprintf_symname(const struct symbol *sym, FILE *fp)
260 {
261         return symbol__fprintf_symname_offs(sym, NULL, fp);
262 }
263 
264 void symbols__delete(struct rb_root *symbols)
265 {
266         struct symbol *pos;
267         struct rb_node *next = rb_first(symbols);
268 
269         while (next) {
270                 pos = rb_entry(next, struct symbol, rb_node);
271                 next = rb_next(&pos->rb_node);
272                 rb_erase(&pos->rb_node, symbols);
273                 symbol__delete(pos);
274         }
275 }
276 
277 void symbols__insert(struct rb_root *symbols, struct symbol *sym)
278 {
279         struct rb_node **p = &symbols->rb_node;
280         struct rb_node *parent = NULL;
281         const u64 ip = sym->start;
282         struct symbol *s;
283 
284         while (*p != NULL) {
285                 parent = *p;
286                 s = rb_entry(parent, struct symbol, rb_node);
287                 if (ip < s->start)
288                         p = &(*p)->rb_left;
289                 else
290                         p = &(*p)->rb_right;
291         }
292         rb_link_node(&sym->rb_node, parent, p);
293         rb_insert_color(&sym->rb_node, symbols);
294 }
295 
296 static struct symbol *symbols__find(struct rb_root *symbols, u64 ip)
297 {
298         struct rb_node *n;
299 
300         if (symbols == NULL)
301                 return NULL;
302 
303         n = symbols->rb_node;
304 
305         while (n) {
306                 struct symbol *s = rb_entry(n, struct symbol, rb_node);
307 
308                 if (ip < s->start)
309                         n = n->rb_left;
310                 else if (ip > s->end)
311                         n = n->rb_right;
312                 else
313                         return s;
314         }
315 
316         return NULL;
317 }
318 
319 struct symbol_name_rb_node {
320         struct rb_node  rb_node;
321         struct symbol   sym;
322 };
323 
324 static void symbols__insert_by_name(struct rb_root *symbols, struct symbol *sym)
325 {
326         struct rb_node **p = &symbols->rb_node;
327         struct rb_node *parent = NULL;
328         struct symbol_name_rb_node *symn, *s;
329 
330         symn = container_of(sym, struct symbol_name_rb_node, sym);
331 
332         while (*p != NULL) {
333                 parent = *p;
334                 s = rb_entry(parent, struct symbol_name_rb_node, rb_node);
335                 if (strcmp(sym->name, s->sym.name) < 0)
336                         p = &(*p)->rb_left;
337                 else
338                         p = &(*p)->rb_right;
339         }
340         rb_link_node(&symn->rb_node, parent, p);
341         rb_insert_color(&symn->rb_node, symbols);
342 }
343 
344 static void symbols__sort_by_name(struct rb_root *symbols,
345                                   struct rb_root *source)
346 {
347         struct rb_node *nd;
348 
349         for (nd = rb_first(source); nd; nd = rb_next(nd)) {
350                 struct symbol *pos = rb_entry(nd, struct symbol, rb_node);
351                 symbols__insert_by_name(symbols, pos);
352         }
353 }
354 
355 static struct symbol *symbols__find_by_name(struct rb_root *symbols,
356                                             const char *name)
357 {
358         struct rb_node *n;
359 
360         if (symbols == NULL)
361                 return NULL;
362 
363         n = symbols->rb_node;
364 
365         while (n) {
366                 struct symbol_name_rb_node *s;
367                 int cmp;
368 
369                 s = rb_entry(n, struct symbol_name_rb_node, rb_node);
370                 cmp = strcmp(name, s->sym.name);
371 
372                 if (cmp < 0)
373                         n = n->rb_left;
374                 else if (cmp > 0)
375                         n = n->rb_right;
376                 else
377                         return &s->sym;
378         }
379 
380         return NULL;
381 }
382 
383 struct symbol *dso__find_symbol(struct dso *dso,
384                                 enum map_type type, u64 addr)
385 {
386         return symbols__find(&dso->symbols[type], addr);
387 }
388 
389 struct symbol *dso__find_symbol_by_name(struct dso *dso, enum map_type type,
390                                         const char *name)
391 {
392         return symbols__find_by_name(&dso->symbol_names[type], name);
393 }
394 
395 void dso__sort_by_name(struct dso *dso, enum map_type type)
396 {
397         dso__set_sorted_by_name(dso, type);
398         return symbols__sort_by_name(&dso->symbol_names[type],
399                                      &dso->symbols[type]);
400 }
401 
402 size_t dso__fprintf_symbols_by_name(struct dso *dso,
403                                     enum map_type type, FILE *fp)
404 {
405         size_t ret = 0;
406         struct rb_node *nd;
407         struct symbol_name_rb_node *pos;
408 
409         for (nd = rb_first(&dso->symbol_names[type]); nd; nd = rb_next(nd)) {
410                 pos = rb_entry(nd, struct symbol_name_rb_node, rb_node);
411                 fprintf(fp, "%s\n", pos->sym.name);
412         }
413 
414         return ret;
415 }
416 
417 int kallsyms__parse(const char *filename, void *arg,
418                     int (*process_symbol)(void *arg, const char *name,
419                                           char type, u64 start))
420 {
421         char *line = NULL;
422         size_t n;
423         int err = -1;
424         FILE *file = fopen(filename, "r");
425 
426         if (file == NULL)
427                 goto out_failure;
428 
429         err = 0;
430 
431         while (!feof(file)) {
432                 u64 start;
433                 int line_len, len;
434                 char symbol_type;
435                 char *symbol_name;
436 
437                 line_len = getline(&line, &n, file);
438                 if (line_len < 0 || !line)
439                         break;
440 
441                 line[--line_len] = '\0'; /* \n */
442 
443                 len = hex2u64(line, &start);
444 
445                 len++;
446                 if (len + 2 >= line_len)
447                         continue;
448 
449                 symbol_type = line[len];
450                 len += 2;
451                 symbol_name = line + len;
452                 len = line_len - len;
453 
454                 if (len >= KSYM_NAME_LEN) {
455                         err = -1;
456                         break;
457                 }
458 
459                 err = process_symbol(arg, symbol_name,
460                                      symbol_type, start);
461                 if (err)
462                         break;
463         }
464 
465         free(line);
466         fclose(file);
467         return err;
468 
469 out_failure:
470         return -1;
471 }
472 
473 struct process_kallsyms_args {
474         struct map *map;
475         struct dso *dso;
476 };
477 
478 static u8 kallsyms2elf_type(char type)
479 {
480         if (type == 'W')
481                 return STB_WEAK;
482 
483         return isupper(type) ? STB_GLOBAL : STB_LOCAL;
484 }
485 
486 static int map__process_kallsym_symbol(void *arg, const char *name,
487                                        char type, u64 start)
488 {
489         struct symbol *sym;
490         struct process_kallsyms_args *a = arg;
491         struct rb_root *root = &a->dso->symbols[a->map->type];
492 
493         if (!symbol_type__is_a(type, a->map->type))
494                 return 0;
495 
496         /*
497          * module symbols are not sorted so we add all
498          * symbols, setting length to 0, and rely on
499          * symbols__fixup_end() to fix it up.
500          */
501         sym = symbol__new(start, 0, kallsyms2elf_type(type), name);
502         if (sym == NULL)
503                 return -ENOMEM;
504         /*
505          * We will pass the symbols to the filter later, in
506          * map__split_kallsyms, when we have split the maps per module
507          */
508         symbols__insert(root, sym);
509 
510         return 0;
511 }
512 
513 /*
514  * Loads the function entries in /proc/kallsyms into kernel_map->dso,
515  * so that we can in the next step set the symbol ->end address and then
516  * call kernel_maps__split_kallsyms.
517  */
518 static int dso__load_all_kallsyms(struct dso *dso, const char *filename,
519                                   struct map *map)
520 {
521         struct process_kallsyms_args args = { .map = map, .dso = dso, };
522         return kallsyms__parse(filename, &args, map__process_kallsym_symbol);
523 }
524 
525 /*
526  * Split the symbols into maps, making sure there are no overlaps, i.e. the
527  * kernel range is broken in several maps, named [kernel].N, as we don't have
528  * the original ELF section names vmlinux have.
529  */
530 static int dso__split_kallsyms(struct dso *dso, struct map *map,
531                                symbol_filter_t filter)
532 {
533         struct map_groups *kmaps = map__kmap(map)->kmaps;
534         struct machine *machine = kmaps->machine;
535         struct map *curr_map = map;
536         struct symbol *pos;
537         int count = 0, moved = 0;       
538         struct rb_root *root = &dso->symbols[map->type];
539         struct rb_node *next = rb_first(root);
540         int kernel_range = 0;
541 
542         while (next) {
543                 char *module;
544 
545                 pos = rb_entry(next, struct symbol, rb_node);
546                 next = rb_next(&pos->rb_node);
547 
548                 module = strchr(pos->name, '\t');
549                 if (module) {
550                         if (!symbol_conf.use_modules)
551                                 goto discard_symbol;
552 
553                         *module++ = '\0';
554 
555                         if (strcmp(curr_map->dso->short_name, module)) {
556                                 if (curr_map != map &&
557                                     dso->kernel == DSO_TYPE_GUEST_KERNEL &&
558                                     machine__is_default_guest(machine)) {
559                                         /*
560                                          * We assume all symbols of a module are
561                                          * continuous in * kallsyms, so curr_map
562                                          * points to a module and all its
563                                          * symbols are in its kmap. Mark it as
564                                          * loaded.
565                                          */
566                                         dso__set_loaded(curr_map->dso,
567                                                         curr_map->type);
568                                 }
569 
570                                 curr_map = map_groups__find_by_name(kmaps,
571                                                         map->type, module);
572                                 if (curr_map == NULL) {
573                                         pr_debug("%s/proc/{kallsyms,modules} "
574                                                  "inconsistency while looking "
575                                                  "for \"%s\" module!\n",
576                                                  machine->root_dir, module);
577                                         curr_map = map;
578                                         goto discard_symbol;
579                                 }
580 
581                                 if (curr_map->dso->loaded &&
582                                     !machine__is_default_guest(machine))
583                                         goto discard_symbol;
584                         }
585                         /*
586                          * So that we look just like we get from .ko files,
587                          * i.e. not prelinked, relative to map->start.
588                          */
589                         pos->start = curr_map->map_ip(curr_map, pos->start);
590                         pos->end   = curr_map->map_ip(curr_map, pos->end);
591                 } else if (curr_map != map) {
592                         char dso_name[PATH_MAX];
593                         struct dso *ndso;
594 
595                         if (count == 0) {
596                                 curr_map = map;
597                                 goto filter_symbol;
598                         }
599 
600                         if (dso->kernel == DSO_TYPE_GUEST_KERNEL)
601                                 snprintf(dso_name, sizeof(dso_name),
602                                         "[guest.kernel].%d",
603                                         kernel_range++);
604                         else
605                                 snprintf(dso_name, sizeof(dso_name),
606                                         "[kernel].%d",
607                                         kernel_range++);
608 
609                         ndso = dso__new(dso_name);
610                         if (ndso == NULL)
611                                 return -1;
612 
613                         ndso->kernel = dso->kernel;
614 
615                         curr_map = map__new2(pos->start, ndso, map->type);
616                         if (curr_map == NULL) {
617                                 dso__delete(ndso);
618                                 return -1;
619                         }
620 
621                         curr_map->map_ip = curr_map->unmap_ip = identity__map_ip;
622                         map_groups__insert(kmaps, curr_map);
623                         ++kernel_range;
624                 }
625 filter_symbol:
626                 if (filter && filter(curr_map, pos)) {
627 discard_symbol:         rb_erase(&pos->rb_node, root);
628                         symbol__delete(pos);
629                 } else {
630                         if (curr_map != map) {
631                                 rb_erase(&pos->rb_node, root);
632                                 symbols__insert(&curr_map->dso->symbols[curr_map->type], pos);
633                                 ++moved;
634                         } else
635                                 ++count;
636                 }
637         }
638 
639         if (curr_map != map &&
640             dso->kernel == DSO_TYPE_GUEST_KERNEL &&
641             machine__is_default_guest(kmaps->machine)) {
642                 dso__set_loaded(curr_map->dso, curr_map->type);
643         }
644 
645         return count + moved;
646 }
647 
648 bool symbol__restricted_filename(const char *filename,
649                                  const char *restricted_filename)
650 {
651         bool restricted = false;
652 
653         if (symbol_conf.kptr_restrict) {
654                 char *r = realpath(filename, NULL);
655 
656                 if (r != NULL) {
657                         restricted = strcmp(r, restricted_filename) == 0;
658                         free(r);
659                         return restricted;
660                 }
661         }
662 
663         return restricted;
664 }
665 
666 int dso__load_kallsyms(struct dso *dso, const char *filename,
667                        struct map *map, symbol_filter_t filter)
668 {
669         if (symbol__restricted_filename(filename, "/proc/kallsyms"))
670                 return -1;
671 
672         if (dso__load_all_kallsyms(dso, filename, map) < 0)
673                 return -1;
674 
675         symbols__fixup_duplicate(&dso->symbols[map->type]);
676         symbols__fixup_end(&dso->symbols[map->type]);
677 
678         if (dso->kernel == DSO_TYPE_GUEST_KERNEL)
679                 dso->symtab_type = DSO_BINARY_TYPE__GUEST_KALLSYMS;
680         else
681                 dso->symtab_type = DSO_BINARY_TYPE__KALLSYMS;
682 
683         return dso__split_kallsyms(dso, map, filter);
684 }
685 
686 static int dso__load_perf_map(struct dso *dso, struct map *map,
687                               symbol_filter_t filter)
688 {
689         char *line = NULL;
690         size_t n;
691         FILE *file;
692         int nr_syms = 0;
693 
694         file = fopen(dso->long_name, "r");
695         if (file == NULL)
696                 goto out_failure;
697 
698         while (!feof(file)) {
699                 u64 start, size;
700                 struct symbol *sym;
701                 int line_len, len;
702 
703                 line_len = getline(&line, &n, file);
704                 if (line_len < 0)
705                         break;
706 
707                 if (!line)
708                         goto out_failure;
709 
710                 line[--line_len] = '\0'; /* \n */
711 
712                 len = hex2u64(line, &start);
713 
714                 len++;
715                 if (len + 2 >= line_len)
716                         continue;
717 
718                 len += hex2u64(line + len, &size);
719 
720                 len++;
721                 if (len + 2 >= line_len)
722                         continue;
723 
724                 sym = symbol__new(start, size, STB_GLOBAL, line + len);
725 
726                 if (sym == NULL)
727                         goto out_delete_line;
728 
729                 if (filter && filter(map, sym))
730                         symbol__delete(sym);
731                 else {
732                         symbols__insert(&dso->symbols[map->type], sym);
733                         nr_syms++;
734                 }
735         }
736 
737         free(line);
738         fclose(file);
739 
740         return nr_syms;
741 
742 out_delete_line:
743         free(line);
744 out_failure:
745         return -1;
746 }
747 
748 int dso__load(struct dso *dso, struct map *map, symbol_filter_t filter)
749 {
750         char *name;
751         int ret = -1;
752         u_int i;
753         struct machine *machine;
754         char *root_dir = (char *) "";
755         int ss_pos = 0;
756         struct symsrc ss_[2];
757         struct symsrc *syms_ss = NULL, *runtime_ss = NULL;
758 
759         dso__set_loaded(dso, map->type);
760 
761         if (dso->kernel == DSO_TYPE_KERNEL)
762                 return dso__load_kernel_sym(dso, map, filter);
763         else if (dso->kernel == DSO_TYPE_GUEST_KERNEL)
764                 return dso__load_guest_kernel_sym(dso, map, filter);
765 
766         if (map->groups && map->groups->machine)
767                 machine = map->groups->machine;
768         else
769                 machine = NULL;
770 
771         dso->adjust_symbols = 0;
772 
773         if (strncmp(dso->name, "/tmp/perf-", 10) == 0) {
774                 struct stat st;
775 
776                 if (lstat(dso->name, &st) < 0)
777                         return -1;
778 
779                 if (st.st_uid && (st.st_uid != geteuid())) {
780                         pr_warning("File %s not owned by current user or root, "
781                                 "ignoring it.\n", dso->name);
782                         return -1;
783                 }
784 
785                 ret = dso__load_perf_map(dso, map, filter);
786                 dso->symtab_type = ret > 0 ? DSO_BINARY_TYPE__JAVA_JIT :
787                                              DSO_BINARY_TYPE__NOT_FOUND;
788                 return ret;
789         }
790 
791         if (machine)
792                 root_dir = machine->root_dir;
793 
794         name = malloc(PATH_MAX);
795         if (!name)
796                 return -1;
797 
798         /* Iterate over candidate debug images.
799          * Keep track of "interesting" ones (those which have a symtab, dynsym,
800          * and/or opd section) for processing.
801          */
802         for (i = 0; i < DSO_BINARY_TYPE__SYMTAB_CNT; i++) {
803                 struct symsrc *ss = &ss_[ss_pos];
804                 bool next_slot = false;
805 
806                 enum dso_binary_type symtab_type = binary_type_symtab[i];
807 
808                 if (dso__binary_type_file(dso, symtab_type,
809                                           root_dir, name, PATH_MAX))
810                         continue;
811 
812                 /* Name is now the name of the next image to try */
813                 if (symsrc__init(ss, dso, name, symtab_type) < 0)
814                         continue;
815 
816                 if (!syms_ss && symsrc__has_symtab(ss)) {
817                         syms_ss = ss;
818                         next_slot = true;
819                 }
820 
821                 if (!runtime_ss && symsrc__possibly_runtime(ss)) {
822                         runtime_ss = ss;
823                         next_slot = true;
824                 }
825 
826                 if (next_slot) {
827                         ss_pos++;
828 
829                         if (syms_ss && runtime_ss)
830                                 break;
831                 }
832 
833         }
834 
835         if (!runtime_ss && !syms_ss)
836                 goto out_free;
837 
838         if (runtime_ss && !syms_ss) {
839                 syms_ss = runtime_ss;
840         }
841 
842         /* We'll have to hope for the best */
843         if (!runtime_ss && syms_ss)
844                 runtime_ss = syms_ss;
845 
846         if (syms_ss)
847                 ret = dso__load_sym(dso, map, syms_ss, runtime_ss, filter, 0);
848         else
849                 ret = -1;
850 
851         if (ret > 0) {
852                 int nr_plt;
853 
854                 nr_plt = dso__synthesize_plt_symbols(dso, runtime_ss, map, filter);
855                 if (nr_plt > 0)
856                         ret += nr_plt;
857         }
858 
859         for (; ss_pos > 0; ss_pos--)
860                 symsrc__destroy(&ss_[ss_pos - 1]);
861 out_free:
862         free(name);
863         if (ret < 0 && strstr(dso->name, " (deleted)") != NULL)
864                 return 0;
865         return ret;
866 }
867 
868 struct map *map_groups__find_by_name(struct map_groups *mg,
869                                      enum map_type type, const char *name)
870 {
871         struct rb_node *nd;
872 
873         for (nd = rb_first(&mg->maps[type]); nd; nd = rb_next(nd)) {
874                 struct map *map = rb_entry(nd, struct map, rb_node);
875 
876                 if (map->dso && strcmp(map->dso->short_name, name) == 0)
877                         return map;
878         }
879 
880         return NULL;
881 }
882 
883 int dso__load_vmlinux(struct dso *dso, struct map *map,
884                       const char *vmlinux, symbol_filter_t filter)
885 {
886         int err = -1;
887         struct symsrc ss;
888         char symfs_vmlinux[PATH_MAX];
889         enum dso_binary_type symtab_type;
890 
891         snprintf(symfs_vmlinux, sizeof(symfs_vmlinux), "%s%s",
892                  symbol_conf.symfs, vmlinux);
893 
894         if (dso->kernel == DSO_TYPE_GUEST_KERNEL)
895                 symtab_type = DSO_BINARY_TYPE__GUEST_VMLINUX;
896         else
897                 symtab_type = DSO_BINARY_TYPE__VMLINUX;
898 
899         if (symsrc__init(&ss, dso, symfs_vmlinux, symtab_type))
900                 return -1;
901 
902         err = dso__load_sym(dso, map, &ss, &ss, filter, 0);
903         symsrc__destroy(&ss);
904 
905         if (err > 0) {
906                 dso__set_long_name(dso, (char *)vmlinux);
907                 dso__set_loaded(dso, map->type);
908                 pr_debug("Using %s for symbols\n", symfs_vmlinux);
909         }
910 
911         return err;
912 }
913 
914 int dso__load_vmlinux_path(struct dso *dso, struct map *map,
915                            symbol_filter_t filter)
916 {
917         int i, err = 0;
918         char *filename;
919 
920         pr_debug("Looking at the vmlinux_path (%d entries long)\n",
921                  vmlinux_path__nr_entries + 1);
922 
923         filename = dso__build_id_filename(dso, NULL, 0);
924         if (filename != NULL) {
925                 err = dso__load_vmlinux(dso, map, filename, filter);
926                 if (err > 0) {
927                         dso->lname_alloc = 1;
928                         goto out;
929                 }
930                 free(filename);
931         }
932 
933         for (i = 0; i < vmlinux_path__nr_entries; ++i) {
934                 err = dso__load_vmlinux(dso, map, vmlinux_path[i], filter);
935                 if (err > 0) {
936                         dso__set_long_name(dso, strdup(vmlinux_path[i]));
937                         dso->lname_alloc = 1;
938                         break;
939                 }
940         }
941 out:
942         return err;
943 }
944 
945 static int dso__load_kernel_sym(struct dso *dso, struct map *map,
946                                 symbol_filter_t filter)
947 {
948         int err;
949         const char *kallsyms_filename = NULL;
950         char *kallsyms_allocated_filename = NULL;
951         /*
952          * Step 1: if the user specified a kallsyms or vmlinux filename, use
953          * it and only it, reporting errors to the user if it cannot be used.
954          *
955          * For instance, try to analyse an ARM perf.data file _without_ a
956          * build-id, or if the user specifies the wrong path to the right
957          * vmlinux file, obviously we can't fallback to another vmlinux (a
958          * x86_86 one, on the machine where analysis is being performed, say),
959          * or worse, /proc/kallsyms.
960          *
961          * If the specified file _has_ a build-id and there is a build-id
962          * section in the perf.data file, we will still do the expected
963          * validation in dso__load_vmlinux and will bail out if they don't
964          * match.
965          */
966         if (symbol_conf.kallsyms_name != NULL) {
967                 kallsyms_filename = symbol_conf.kallsyms_name;
968                 goto do_kallsyms;
969         }
970 
971         if (symbol_conf.vmlinux_name != NULL) {
972                 err = dso__load_vmlinux(dso, map,
973                                         symbol_conf.vmlinux_name, filter);
974                 if (err > 0) {
975                         dso__set_long_name(dso,
976                                            strdup(symbol_conf.vmlinux_name));
977                         dso->lname_alloc = 1;
978                         goto out_fixup;
979                 }
980                 return err;
981         }
982 
983         if (vmlinux_path != NULL) {
984                 err = dso__load_vmlinux_path(dso, map, filter);
985                 if (err > 0)
986                         goto out_fixup;
987         }
988 
989         /* do not try local files if a symfs was given */
990         if (symbol_conf.symfs[0] != 0)
991                 return -1;
992 
993         /*
994          * Say the kernel DSO was created when processing the build-id header table,
995          * we have a build-id, so check if it is the same as the running kernel,
996          * using it if it is.
997          */
998         if (dso->has_build_id) {
999                 u8 kallsyms_build_id[BUILD_ID_SIZE];
1000                 char sbuild_id[BUILD_ID_SIZE * 2 + 1];
1001 
1002                 if (sysfs__read_build_id("/sys/kernel/notes", kallsyms_build_id,
1003                                          sizeof(kallsyms_build_id)) == 0) {
1004                         if (dso__build_id_equal(dso, kallsyms_build_id)) {
1005                                 kallsyms_filename = "/proc/kallsyms";
1006                                 goto do_kallsyms;
1007                         }
1008                 }
1009                 /*
1010                  * Now look if we have it on the build-id cache in
1011                  * $HOME/.debug/[kernel.kallsyms].
1012                  */
1013                 build_id__sprintf(dso->build_id, sizeof(dso->build_id),
1014                                   sbuild_id);
1015 
1016                 if (asprintf(&kallsyms_allocated_filename,
1017                              "%s/.debug/[kernel.kallsyms]/%s",
1018                              getenv("HOME"), sbuild_id) == -1) {
1019                         pr_err("Not enough memory for kallsyms file lookup\n");
1020                         return -1;
1021                 }
1022 
1023                 kallsyms_filename = kallsyms_allocated_filename;
1024 
1025                 if (access(kallsyms_filename, F_OK)) {
1026                         pr_err("No kallsyms or vmlinux with build-id %s "
1027                                "was found\n", sbuild_id);
1028                         free(kallsyms_allocated_filename);
1029                         return -1;
1030                 }
1031         } else {
1032                 /*
1033                  * Last resort, if we don't have a build-id and couldn't find
1034                  * any vmlinux file, try the running kernel kallsyms table.
1035                  */
1036                 kallsyms_filename = "/proc/kallsyms";
1037         }
1038 
1039 do_kallsyms:
1040         err = dso__load_kallsyms(dso, kallsyms_filename, map, filter);
1041         if (err > 0)
1042                 pr_debug("Using %s for symbols\n", kallsyms_filename);
1043         free(kallsyms_allocated_filename);
1044 
1045         if (err > 0) {
1046                 dso__set_long_name(dso, strdup("[kernel.kallsyms]"));
1047 out_fixup:
1048                 map__fixup_start(map);
1049                 map__fixup_end(map);
1050         }
1051 
1052         return err;
1053 }
1054 
1055 static int dso__load_guest_kernel_sym(struct dso *dso, struct map *map,
1056                                       symbol_filter_t filter)
1057 {
1058         int err;
1059         const char *kallsyms_filename = NULL;
1060         struct machine *machine;
1061         char path[PATH_MAX];
1062 
1063         if (!map->groups) {
1064                 pr_debug("Guest kernel map hasn't the point to groups\n");
1065                 return -1;
1066         }
1067         machine = map->groups->machine;
1068 
1069         if (machine__is_default_guest(machine)) {
1070                 /*
1071                  * if the user specified a vmlinux filename, use it and only
1072                  * it, reporting errors to the user if it cannot be used.
1073                  * Or use file guest_kallsyms inputted by user on commandline
1074                  */
1075                 if (symbol_conf.default_guest_vmlinux_name != NULL) {
1076                         err = dso__load_vmlinux(dso, map,
1077                                 symbol_conf.default_guest_vmlinux_name, filter);
1078                         goto out_try_fixup;
1079                 }
1080 
1081                 kallsyms_filename = symbol_conf.default_guest_kallsyms;
1082                 if (!kallsyms_filename)
1083                         return -1;
1084         } else {
1085                 sprintf(path, "%s/proc/kallsyms", machine->root_dir);
1086                 kallsyms_filename = path;
1087         }
1088 
1089         err = dso__load_kallsyms(dso, kallsyms_filename, map, filter);
1090         if (err > 0)
1091                 pr_debug("Using %s for symbols\n", kallsyms_filename);
1092 
1093 out_try_fixup:
1094         if (err > 0) {
1095                 if (kallsyms_filename != NULL) {
1096                         machine__mmap_name(machine, path, sizeof(path));
1097                         dso__set_long_name(dso, strdup(path));
1098                 }
1099                 map__fixup_start(map);
1100                 map__fixup_end(map);
1101         }
1102 
1103         return err;
1104 }
1105 
1106 static void vmlinux_path__exit(void)
1107 {
1108         while (--vmlinux_path__nr_entries >= 0) {
1109                 free(vmlinux_path[vmlinux_path__nr_entries]);
1110                 vmlinux_path[vmlinux_path__nr_entries] = NULL;
1111         }
1112 
1113         free(vmlinux_path);
1114         vmlinux_path = NULL;
1115 }
1116 
1117 static int vmlinux_path__init(void)
1118 {
1119         struct utsname uts;
1120         char bf[PATH_MAX];
1121 
1122         vmlinux_path = malloc(sizeof(char *) * 5);
1123         if (vmlinux_path == NULL)
1124                 return -1;
1125 
1126         vmlinux_path[vmlinux_path__nr_entries] = strdup("vmlinux");
1127         if (vmlinux_path[vmlinux_path__nr_entries] == NULL)
1128                 goto out_fail;
1129         ++vmlinux_path__nr_entries;
1130         vmlinux_path[vmlinux_path__nr_entries] = strdup("/boot/vmlinux");
1131         if (vmlinux_path[vmlinux_path__nr_entries] == NULL)
1132                 goto out_fail;
1133         ++vmlinux_path__nr_entries;
1134 
1135         /* only try running kernel version if no symfs was given */
1136         if (symbol_conf.symfs[0] != 0)
1137                 return 0;
1138 
1139         if (uname(&uts) < 0)
1140                 return -1;
1141 
1142         snprintf(bf, sizeof(bf), "/boot/vmlinux-%s", uts.release);
1143         vmlinux_path[vmlinux_path__nr_entries] = strdup(bf);
1144         if (vmlinux_path[vmlinux_path__nr_entries] == NULL)
1145                 goto out_fail;
1146         ++vmlinux_path__nr_entries;
1147         snprintf(bf, sizeof(bf), "/lib/modules/%s/build/vmlinux", uts.release);
1148         vmlinux_path[vmlinux_path__nr_entries] = strdup(bf);
1149         if (vmlinux_path[vmlinux_path__nr_entries] == NULL)
1150                 goto out_fail;
1151         ++vmlinux_path__nr_entries;
1152         snprintf(bf, sizeof(bf), "/usr/lib/debug/lib/modules/%s/vmlinux",
1153                  uts.release);
1154         vmlinux_path[vmlinux_path__nr_entries] = strdup(bf);
1155         if (vmlinux_path[vmlinux_path__nr_entries] == NULL)
1156                 goto out_fail;
1157         ++vmlinux_path__nr_entries;
1158 
1159         return 0;
1160 
1161 out_fail:
1162         vmlinux_path__exit();
1163         return -1;
1164 }
1165 
1166 static int setup_list(struct strlist **list, const char *list_str,
1167                       const char *list_name)
1168 {
1169         if (list_str == NULL)
1170                 return 0;
1171 
1172         *list = strlist__new(true, list_str);
1173         if (!*list) {
1174                 pr_err("problems parsing %s list\n", list_name);
1175                 return -1;
1176         }
1177         return 0;
1178 }
1179 
1180 static bool symbol__read_kptr_restrict(void)
1181 {
1182         bool value = false;
1183 
1184         if (geteuid() != 0) {
1185                 FILE *fp = fopen("/proc/sys/kernel/kptr_restrict", "r");
1186                 if (fp != NULL) {
1187                         char line[8];
1188 
1189                         if (fgets(line, sizeof(line), fp) != NULL)
1190                                 value = atoi(line) != 0;
1191 
1192                         fclose(fp);
1193                 }
1194         }
1195 
1196         return value;
1197 }
1198 
1199 int symbol__init(void)
1200 {
1201         const char *symfs;
1202 
1203         if (symbol_conf.initialized)
1204                 return 0;
1205 
1206         symbol_conf.priv_size = PERF_ALIGN(symbol_conf.priv_size, sizeof(u64));
1207 
1208         symbol__elf_init();
1209 
1210         if (symbol_conf.sort_by_name)
1211                 symbol_conf.priv_size += (sizeof(struct symbol_name_rb_node) -
1212                                           sizeof(struct symbol));
1213 
1214         if (symbol_conf.try_vmlinux_path && vmlinux_path__init() < 0)
1215                 return -1;
1216 
1217         if (symbol_conf.field_sep && *symbol_conf.field_sep == '.') {
1218                 pr_err("'.' is the only non valid --field-separator argument\n");
1219                 return -1;
1220         }
1221 
1222         if (setup_list(&symbol_conf.dso_list,
1223                        symbol_conf.dso_list_str, "dso") < 0)
1224                 return -1;
1225 
1226         if (setup_list(&symbol_conf.comm_list,
1227                        symbol_conf.comm_list_str, "comm") < 0)
1228                 goto out_free_dso_list;
1229 
1230         if (setup_list(&symbol_conf.sym_list,
1231                        symbol_conf.sym_list_str, "symbol") < 0)
1232                 goto out_free_comm_list;
1233 
1234         /*
1235          * A path to symbols of "/" is identical to ""
1236          * reset here for simplicity.
1237          */
1238         symfs = realpath(symbol_conf.symfs, NULL);
1239         if (symfs == NULL)
1240                 symfs = symbol_conf.symfs;
1241         if (strcmp(symfs, "/") == 0)
1242                 symbol_conf.symfs = "";
1243         if (symfs != symbol_conf.symfs)
1244                 free((void *)symfs);
1245 
1246         symbol_conf.kptr_restrict = symbol__read_kptr_restrict();
1247 
1248         symbol_conf.initialized = true;
1249         return 0;
1250 
1251 out_free_comm_list:
1252         strlist__delete(symbol_conf.comm_list);
1253 out_free_dso_list:
1254         strlist__delete(symbol_conf.dso_list);
1255         return -1;
1256 }
1257 
1258 void symbol__exit(void)
1259 {
1260         if (!symbol_conf.initialized)
1261                 return;
1262         strlist__delete(symbol_conf.sym_list);
1263         strlist__delete(symbol_conf.dso_list);
1264         strlist__delete(symbol_conf.comm_list);
1265         vmlinux_path__exit();
1266         symbol_conf.sym_list = symbol_conf.dso_list = symbol_conf.comm_list = NULL;
1267         symbol_conf.initialized = false;
1268 }
1269 

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