1 // SPDX-License-Identifier: GPL-2.0
2 #include <dirent.h>
3 #include <errno.h>
4 #include <stdlib.h>
5 #include <stdio.h>
6 #include <string.h>
7 #include <linux/capability.h>
8 #include <linux/kernel.h>
9 #include <linux/mman.h>
10 #include <linux/string.h>
11 #include <linux/time64.h>
12 #include <sys/types.h>
13 #include <sys/stat.h>
14 #include <sys/param.h>
15 #include <fcntl.h>
16 #include <unistd.h>
17 #include <inttypes.h>
18 #include "annotate.h"
19 #include "build-id.h"
20 #include "cap.h"
21 #include "dso.h"
22 #include "util.h" // lsdir()
23 #include "debug.h"
24 #include "event.h"
25 #include "machine.h"
26 #include "map.h"
27 #include "symbol.h"
28 #include "map_symbol.h"
29 #include "mem-events.h"
30 #include "symsrc.h"
31 #include "strlist.h"
32 #include "intlist.h"
33 #include "namespaces.h"
34 #include "header.h"
35 #include "path.h"
36 #include <linux/ctype.h>
37 #include <linux/zalloc.h>
38
39 #include <elf.h>
40 #include <limits.h>
41 #include <symbol/kallsyms.h>
42 #include <sys/utsname.h>
43
44 static int dso__load_kernel_sym(struct dso *dso, struct map *map);
45 static int dso__load_guest_kernel_sym(struct dso *dso, struct map *map);
46 static bool symbol__is_idle(const char *name);
47
48 int vmlinux_path__nr_entries;
49 char **vmlinux_path;
50
51 struct symbol_conf symbol_conf = {
52 .nanosecs = false,
53 .use_modules = true,
54 .try_vmlinux_path = true,
55 .demangle = true,
56 .demangle_kernel = false,
57 .cumulate_callchain = true,
58 .time_quantum = 100 * NSEC_PER_MSEC, /* 100ms */
59 .show_hist_headers = true,
60 .symfs = "",
61 .event_group = true,
62 .inline_name = true,
63 .res_sample = 0,
64 };
65
66 static enum dso_binary_type binary_type_symtab[] = {
67 DSO_BINARY_TYPE__KALLSYMS,
68 DSO_BINARY_TYPE__GUEST_KALLSYMS,
69 DSO_BINARY_TYPE__JAVA_JIT,
70 DSO_BINARY_TYPE__DEBUGLINK,
71 DSO_BINARY_TYPE__BUILD_ID_CACHE,
72 DSO_BINARY_TYPE__BUILD_ID_CACHE_DEBUGINFO,
73 DSO_BINARY_TYPE__FEDORA_DEBUGINFO,
74 DSO_BINARY_TYPE__UBUNTU_DEBUGINFO,
75 DSO_BINARY_TYPE__BUILDID_DEBUGINFO,
76 DSO_BINARY_TYPE__SYSTEM_PATH_DSO,
77 DSO_BINARY_TYPE__GUEST_KMODULE,
78 DSO_BINARY_TYPE__GUEST_KMODULE_COMP,
79 DSO_BINARY_TYPE__SYSTEM_PATH_KMODULE,
80 DSO_BINARY_TYPE__SYSTEM_PATH_KMODULE_COMP,
81 DSO_BINARY_TYPE__OPENEMBEDDED_DEBUGINFO,
82 DSO_BINARY_TYPE__MIXEDUP_UBUNTU_DEBUGINFO,
83 DSO_BINARY_TYPE__NOT_FOUND,
84 };
85
86 #define DSO_BINARY_TYPE__SYMTAB_CNT ARRAY_SIZE(binary_type_symtab)
87
symbol_type__filter(char symbol_type)88 static bool symbol_type__filter(char symbol_type)
89 {
90 symbol_type = toupper(symbol_type);
91 return symbol_type == 'T' || symbol_type == 'W' || symbol_type == 'D' || symbol_type == 'B';
92 }
93
prefix_underscores_count(const char * str)94 static int prefix_underscores_count(const char *str)
95 {
96 const char *tail = str;
97
98 while (*tail == '_')
99 tail++;
100
101 return tail - str;
102 }
103
arch__normalize_symbol_name(const char * name)104 const char * __weak arch__normalize_symbol_name(const char *name)
105 {
106 return name;
107 }
108
arch__compare_symbol_names(const char * namea,const char * nameb)109 int __weak arch__compare_symbol_names(const char *namea, const char *nameb)
110 {
111 return strcmp(namea, nameb);
112 }
113
arch__compare_symbol_names_n(const char * namea,const char * nameb,unsigned int n)114 int __weak arch__compare_symbol_names_n(const char *namea, const char *nameb,
115 unsigned int n)
116 {
117 return strncmp(namea, nameb, n);
118 }
119
arch__choose_best_symbol(struct symbol * syma,struct symbol * symb __maybe_unused)120 int __weak arch__choose_best_symbol(struct symbol *syma,
121 struct symbol *symb __maybe_unused)
122 {
123 /* Avoid "SyS" kernel syscall aliases */
124 if (strlen(syma->name) >= 3 && !strncmp(syma->name, "SyS", 3))
125 return SYMBOL_B;
126 if (strlen(syma->name) >= 10 && !strncmp(syma->name, "compat_SyS", 10))
127 return SYMBOL_B;
128
129 return SYMBOL_A;
130 }
131
choose_best_symbol(struct symbol * syma,struct symbol * symb)132 static int choose_best_symbol(struct symbol *syma, struct symbol *symb)
133 {
134 s64 a;
135 s64 b;
136 size_t na, nb;
137
138 /* Prefer a symbol with non zero length */
139 a = syma->end - syma->start;
140 b = symb->end - symb->start;
141 if ((b == 0) && (a > 0))
142 return SYMBOL_A;
143 else if ((a == 0) && (b > 0))
144 return SYMBOL_B;
145
146 /* Prefer a non weak symbol over a weak one */
147 a = syma->binding == STB_WEAK;
148 b = symb->binding == STB_WEAK;
149 if (b && !a)
150 return SYMBOL_A;
151 if (a && !b)
152 return SYMBOL_B;
153
154 /* Prefer a global symbol over a non global one */
155 a = syma->binding == STB_GLOBAL;
156 b = symb->binding == STB_GLOBAL;
157 if (a && !b)
158 return SYMBOL_A;
159 if (b && !a)
160 return SYMBOL_B;
161
162 /* Prefer a symbol with less underscores */
163 a = prefix_underscores_count(syma->name);
164 b = prefix_underscores_count(symb->name);
165 if (b > a)
166 return SYMBOL_A;
167 else if (a > b)
168 return SYMBOL_B;
169
170 /* Choose the symbol with the longest name */
171 na = strlen(syma->name);
172 nb = strlen(symb->name);
173 if (na > nb)
174 return SYMBOL_A;
175 else if (na < nb)
176 return SYMBOL_B;
177
178 return arch__choose_best_symbol(syma, symb);
179 }
180
symbols__fixup_duplicate(struct rb_root_cached * symbols)181 void symbols__fixup_duplicate(struct rb_root_cached *symbols)
182 {
183 struct rb_node *nd;
184 struct symbol *curr, *next;
185
186 if (symbol_conf.allow_aliases)
187 return;
188
189 nd = rb_first_cached(symbols);
190
191 while (nd) {
192 curr = rb_entry(nd, struct symbol, rb_node);
193 again:
194 nd = rb_next(&curr->rb_node);
195 next = rb_entry(nd, struct symbol, rb_node);
196
197 if (!nd)
198 break;
199
200 if (curr->start != next->start)
201 continue;
202
203 if (choose_best_symbol(curr, next) == SYMBOL_A) {
204 rb_erase_cached(&next->rb_node, symbols);
205 symbol__delete(next);
206 goto again;
207 } else {
208 nd = rb_next(&curr->rb_node);
209 rb_erase_cached(&curr->rb_node, symbols);
210 symbol__delete(curr);
211 }
212 }
213 }
214
215 /* Update zero-sized symbols using the address of the next symbol */
symbols__fixup_end(struct rb_root_cached * symbols,bool is_kallsyms)216 void symbols__fixup_end(struct rb_root_cached *symbols, bool is_kallsyms)
217 {
218 struct rb_node *nd, *prevnd = rb_first_cached(symbols);
219 struct symbol *curr, *prev;
220
221 if (prevnd == NULL)
222 return;
223
224 curr = rb_entry(prevnd, struct symbol, rb_node);
225
226 for (nd = rb_next(prevnd); nd; nd = rb_next(nd)) {
227 prev = curr;
228 curr = rb_entry(nd, struct symbol, rb_node);
229
230 /*
231 * On some architecture kernel text segment start is located at
232 * some low memory address, while modules are located at high
233 * memory addresses (or vice versa). The gap between end of
234 * kernel text segment and beginning of first module's text
235 * segment is very big. Therefore do not fill this gap and do
236 * not assign it to the kernel dso map (kallsyms).
237 *
238 * In kallsyms, it determines module symbols using '[' character
239 * like in:
240 * ffffffffc1937000 T hdmi_driver_init [snd_hda_codec_hdmi]
241 */
242 if (prev->end == prev->start) {
243 /* Last kernel/module symbol mapped to end of page */
244 if (is_kallsyms && (!strchr(prev->name, '[') !=
245 !strchr(curr->name, '[')))
246 prev->end = roundup(prev->end + 4096, 4096);
247 else
248 prev->end = curr->start;
249
250 pr_debug4("%s sym:%s end:%#" PRIx64 "\n",
251 __func__, prev->name, prev->end);
252 }
253 }
254
255 /* Last entry */
256 if (curr->end == curr->start)
257 curr->end = roundup(curr->start, 4096) + 4096;
258 }
259
maps__fixup_end(struct maps * maps)260 void maps__fixup_end(struct maps *maps)
261 {
262 struct map *prev = NULL, *curr;
263
264 down_write(&maps->lock);
265
266 maps__for_each_entry(maps, curr) {
267 if (prev != NULL && !prev->end)
268 prev->end = curr->start;
269
270 prev = curr;
271 }
272
273 /*
274 * We still haven't the actual symbols, so guess the
275 * last map final address.
276 */
277 if (curr && !curr->end)
278 curr->end = ~0ULL;
279
280 up_write(&maps->lock);
281 }
282
symbol__new(u64 start,u64 len,u8 binding,u8 type,const char * name)283 struct symbol *symbol__new(u64 start, u64 len, u8 binding, u8 type, const char *name)
284 {
285 size_t namelen = strlen(name) + 1;
286 struct symbol *sym = calloc(1, (symbol_conf.priv_size +
287 sizeof(*sym) + namelen));
288 if (sym == NULL)
289 return NULL;
290
291 if (symbol_conf.priv_size) {
292 if (symbol_conf.init_annotation) {
293 struct annotation *notes = (void *)sym;
294 annotation__init(notes);
295 }
296 sym = ((void *)sym) + symbol_conf.priv_size;
297 }
298
299 sym->start = start;
300 sym->end = len ? start + len : start;
301 sym->type = type;
302 sym->binding = binding;
303 sym->namelen = namelen - 1;
304
305 pr_debug4("%s: %s %#" PRIx64 "-%#" PRIx64 "\n",
306 __func__, name, start, sym->end);
307 memcpy(sym->name, name, namelen);
308
309 return sym;
310 }
311
symbol__delete(struct symbol * sym)312 void symbol__delete(struct symbol *sym)
313 {
314 if (symbol_conf.priv_size) {
315 if (symbol_conf.init_annotation) {
316 struct annotation *notes = symbol__annotation(sym);
317
318 annotation__exit(notes);
319 }
320 }
321 free(((void *)sym) - symbol_conf.priv_size);
322 }
323
symbols__delete(struct rb_root_cached * symbols)324 void symbols__delete(struct rb_root_cached *symbols)
325 {
326 struct symbol *pos;
327 struct rb_node *next = rb_first_cached(symbols);
328
329 while (next) {
330 pos = rb_entry(next, struct symbol, rb_node);
331 next = rb_next(&pos->rb_node);
332 rb_erase_cached(&pos->rb_node, symbols);
333 symbol__delete(pos);
334 }
335 }
336
__symbols__insert(struct rb_root_cached * symbols,struct symbol * sym,bool kernel)337 void __symbols__insert(struct rb_root_cached *symbols,
338 struct symbol *sym, bool kernel)
339 {
340 struct rb_node **p = &symbols->rb_root.rb_node;
341 struct rb_node *parent = NULL;
342 const u64 ip = sym->start;
343 struct symbol *s;
344 bool leftmost = true;
345
346 if (kernel) {
347 const char *name = sym->name;
348 /*
349 * ppc64 uses function descriptors and appends a '.' to the
350 * start of every instruction address. Remove it.
351 */
352 if (name[0] == '.')
353 name++;
354 sym->idle = symbol__is_idle(name);
355 }
356
357 while (*p != NULL) {
358 parent = *p;
359 s = rb_entry(parent, struct symbol, rb_node);
360 if (ip < s->start)
361 p = &(*p)->rb_left;
362 else {
363 p = &(*p)->rb_right;
364 leftmost = false;
365 }
366 }
367 rb_link_node(&sym->rb_node, parent, p);
368 rb_insert_color_cached(&sym->rb_node, symbols, leftmost);
369 }
370
symbols__insert(struct rb_root_cached * symbols,struct symbol * sym)371 void symbols__insert(struct rb_root_cached *symbols, struct symbol *sym)
372 {
373 __symbols__insert(symbols, sym, false);
374 }
375
symbols__find(struct rb_root_cached * symbols,u64 ip)376 static struct symbol *symbols__find(struct rb_root_cached *symbols, u64 ip)
377 {
378 struct rb_node *n;
379
380 if (symbols == NULL)
381 return NULL;
382
383 n = symbols->rb_root.rb_node;
384
385 while (n) {
386 struct symbol *s = rb_entry(n, struct symbol, rb_node);
387
388 if (ip < s->start)
389 n = n->rb_left;
390 else if (ip > s->end || (ip == s->end && ip != s->start))
391 n = n->rb_right;
392 else
393 return s;
394 }
395
396 return NULL;
397 }
398
symbols__first(struct rb_root_cached * symbols)399 static struct symbol *symbols__first(struct rb_root_cached *symbols)
400 {
401 struct rb_node *n = rb_first_cached(symbols);
402
403 if (n)
404 return rb_entry(n, struct symbol, rb_node);
405
406 return NULL;
407 }
408
symbols__last(struct rb_root_cached * symbols)409 static struct symbol *symbols__last(struct rb_root_cached *symbols)
410 {
411 struct rb_node *n = rb_last(&symbols->rb_root);
412
413 if (n)
414 return rb_entry(n, struct symbol, rb_node);
415
416 return NULL;
417 }
418
symbols__next(struct symbol * sym)419 static struct symbol *symbols__next(struct symbol *sym)
420 {
421 struct rb_node *n = rb_next(&sym->rb_node);
422
423 if (n)
424 return rb_entry(n, struct symbol, rb_node);
425
426 return NULL;
427 }
428
symbols__insert_by_name(struct rb_root_cached * symbols,struct symbol * sym)429 static void symbols__insert_by_name(struct rb_root_cached *symbols, struct symbol *sym)
430 {
431 struct rb_node **p = &symbols->rb_root.rb_node;
432 struct rb_node *parent = NULL;
433 struct symbol_name_rb_node *symn, *s;
434 bool leftmost = true;
435
436 symn = container_of(sym, struct symbol_name_rb_node, sym);
437
438 while (*p != NULL) {
439 parent = *p;
440 s = rb_entry(parent, struct symbol_name_rb_node, rb_node);
441 if (strcmp(sym->name, s->sym.name) < 0)
442 p = &(*p)->rb_left;
443 else {
444 p = &(*p)->rb_right;
445 leftmost = false;
446 }
447 }
448 rb_link_node(&symn->rb_node, parent, p);
449 rb_insert_color_cached(&symn->rb_node, symbols, leftmost);
450 }
451
symbols__sort_by_name(struct rb_root_cached * symbols,struct rb_root_cached * source)452 static void symbols__sort_by_name(struct rb_root_cached *symbols,
453 struct rb_root_cached *source)
454 {
455 struct rb_node *nd;
456
457 for (nd = rb_first_cached(source); nd; nd = rb_next(nd)) {
458 struct symbol *pos = rb_entry(nd, struct symbol, rb_node);
459 symbols__insert_by_name(symbols, pos);
460 }
461 }
462
symbol__match_symbol_name(const char * name,const char * str,enum symbol_tag_include includes)463 int symbol__match_symbol_name(const char *name, const char *str,
464 enum symbol_tag_include includes)
465 {
466 const char *versioning;
467
468 if (includes == SYMBOL_TAG_INCLUDE__DEFAULT_ONLY &&
469 (versioning = strstr(name, "@@"))) {
470 int len = strlen(str);
471
472 if (len < versioning - name)
473 len = versioning - name;
474
475 return arch__compare_symbol_names_n(name, str, len);
476 } else
477 return arch__compare_symbol_names(name, str);
478 }
479
symbols__find_by_name(struct rb_root_cached * symbols,const char * name,enum symbol_tag_include includes)480 static struct symbol *symbols__find_by_name(struct rb_root_cached *symbols,
481 const char *name,
482 enum symbol_tag_include includes)
483 {
484 struct rb_node *n;
485 struct symbol_name_rb_node *s = NULL;
486
487 if (symbols == NULL)
488 return NULL;
489
490 n = symbols->rb_root.rb_node;
491
492 while (n) {
493 int cmp;
494
495 s = rb_entry(n, struct symbol_name_rb_node, rb_node);
496 cmp = symbol__match_symbol_name(s->sym.name, name, includes);
497
498 if (cmp > 0)
499 n = n->rb_left;
500 else if (cmp < 0)
501 n = n->rb_right;
502 else
503 break;
504 }
505
506 if (n == NULL)
507 return NULL;
508
509 if (includes != SYMBOL_TAG_INCLUDE__DEFAULT_ONLY)
510 /* return first symbol that has same name (if any) */
511 for (n = rb_prev(n); n; n = rb_prev(n)) {
512 struct symbol_name_rb_node *tmp;
513
514 tmp = rb_entry(n, struct symbol_name_rb_node, rb_node);
515 if (arch__compare_symbol_names(tmp->sym.name, s->sym.name))
516 break;
517
518 s = tmp;
519 }
520
521 return &s->sym;
522 }
523
dso__reset_find_symbol_cache(struct dso * dso)524 void dso__reset_find_symbol_cache(struct dso *dso)
525 {
526 dso->last_find_result.addr = 0;
527 dso->last_find_result.symbol = NULL;
528 }
529
dso__insert_symbol(struct dso * dso,struct symbol * sym)530 void dso__insert_symbol(struct dso *dso, struct symbol *sym)
531 {
532 __symbols__insert(&dso->symbols, sym, dso->kernel);
533
534 /* update the symbol cache if necessary */
535 if (dso->last_find_result.addr >= sym->start &&
536 (dso->last_find_result.addr < sym->end ||
537 sym->start == sym->end)) {
538 dso->last_find_result.symbol = sym;
539 }
540 }
541
dso__delete_symbol(struct dso * dso,struct symbol * sym)542 void dso__delete_symbol(struct dso *dso, struct symbol *sym)
543 {
544 rb_erase_cached(&sym->rb_node, &dso->symbols);
545 symbol__delete(sym);
546 dso__reset_find_symbol_cache(dso);
547 }
548
dso__find_symbol(struct dso * dso,u64 addr)549 struct symbol *dso__find_symbol(struct dso *dso, u64 addr)
550 {
551 if (dso->last_find_result.addr != addr || dso->last_find_result.symbol == NULL) {
552 dso->last_find_result.addr = addr;
553 dso->last_find_result.symbol = symbols__find(&dso->symbols, addr);
554 }
555
556 return dso->last_find_result.symbol;
557 }
558
dso__first_symbol(struct dso * dso)559 struct symbol *dso__first_symbol(struct dso *dso)
560 {
561 return symbols__first(&dso->symbols);
562 }
563
dso__last_symbol(struct dso * dso)564 struct symbol *dso__last_symbol(struct dso *dso)
565 {
566 return symbols__last(&dso->symbols);
567 }
568
dso__next_symbol(struct symbol * sym)569 struct symbol *dso__next_symbol(struct symbol *sym)
570 {
571 return symbols__next(sym);
572 }
573
symbol__next_by_name(struct symbol * sym)574 struct symbol *symbol__next_by_name(struct symbol *sym)
575 {
576 struct symbol_name_rb_node *s = container_of(sym, struct symbol_name_rb_node, sym);
577 struct rb_node *n = rb_next(&s->rb_node);
578
579 return n ? &rb_entry(n, struct symbol_name_rb_node, rb_node)->sym : NULL;
580 }
581
582 /*
583 * Returns first symbol that matched with @name.
584 */
dso__find_symbol_by_name(struct dso * dso,const char * name)585 struct symbol *dso__find_symbol_by_name(struct dso *dso, const char *name)
586 {
587 struct symbol *s = symbols__find_by_name(&dso->symbol_names, name,
588 SYMBOL_TAG_INCLUDE__NONE);
589 if (!s)
590 s = symbols__find_by_name(&dso->symbol_names, name,
591 SYMBOL_TAG_INCLUDE__DEFAULT_ONLY);
592 return s;
593 }
594
dso__sort_by_name(struct dso * dso)595 void dso__sort_by_name(struct dso *dso)
596 {
597 dso__set_sorted_by_name(dso);
598 return symbols__sort_by_name(&dso->symbol_names, &dso->symbols);
599 }
600
601 /*
602 * While we find nice hex chars, build a long_val.
603 * Return number of chars processed.
604 */
hex2u64(const char * ptr,u64 * long_val)605 static int hex2u64(const char *ptr, u64 *long_val)
606 {
607 char *p;
608
609 *long_val = strtoull(ptr, &p, 16);
610
611 return p - ptr;
612 }
613
614
modules__parse(const char * filename,void * arg,int (* process_module)(void * arg,const char * name,u64 start,u64 size))615 int modules__parse(const char *filename, void *arg,
616 int (*process_module)(void *arg, const char *name,
617 u64 start, u64 size))
618 {
619 char *line = NULL;
620 size_t n;
621 FILE *file;
622 int err = 0;
623
624 file = fopen(filename, "r");
625 if (file == NULL)
626 return -1;
627
628 while (1) {
629 char name[PATH_MAX];
630 u64 start, size;
631 char *sep, *endptr;
632 ssize_t line_len;
633
634 line_len = getline(&line, &n, file);
635 if (line_len < 0) {
636 if (feof(file))
637 break;
638 err = -1;
639 goto out;
640 }
641
642 if (!line) {
643 err = -1;
644 goto out;
645 }
646
647 line[--line_len] = '\0'; /* \n */
648
649 sep = strrchr(line, 'x');
650 if (sep == NULL)
651 continue;
652
653 hex2u64(sep + 1, &start);
654
655 sep = strchr(line, ' ');
656 if (sep == NULL)
657 continue;
658
659 *sep = '\0';
660
661 scnprintf(name, sizeof(name), "[%s]", line);
662
663 size = strtoul(sep + 1, &endptr, 0);
664 if (*endptr != ' ' && *endptr != '\t')
665 continue;
666
667 err = process_module(arg, name, start, size);
668 if (err)
669 break;
670 }
671 out:
672 free(line);
673 fclose(file);
674 return err;
675 }
676
677 /*
678 * These are symbols in the kernel image, so make sure that
679 * sym is from a kernel DSO.
680 */
symbol__is_idle(const char * name)681 static bool symbol__is_idle(const char *name)
682 {
683 const char * const idle_symbols[] = {
684 "acpi_idle_do_entry",
685 "acpi_processor_ffh_cstate_enter",
686 "arch_cpu_idle",
687 "cpu_idle",
688 "cpu_startup_entry",
689 "idle_cpu",
690 "intel_idle",
691 "default_idle",
692 "native_safe_halt",
693 "enter_idle",
694 "exit_idle",
695 "mwait_idle",
696 "mwait_idle_with_hints",
697 "mwait_idle_with_hints.constprop.0",
698 "poll_idle",
699 "ppc64_runlatch_off",
700 "pseries_dedicated_idle_sleep",
701 "psw_idle",
702 "psw_idle_exit",
703 NULL
704 };
705 int i;
706 static struct strlist *idle_symbols_list;
707
708 if (idle_symbols_list)
709 return strlist__has_entry(idle_symbols_list, name);
710
711 idle_symbols_list = strlist__new(NULL, NULL);
712
713 for (i = 0; idle_symbols[i]; i++)
714 strlist__add(idle_symbols_list, idle_symbols[i]);
715
716 return strlist__has_entry(idle_symbols_list, name);
717 }
718
map__process_kallsym_symbol(void * arg,const char * name,char type,u64 start)719 static int map__process_kallsym_symbol(void *arg, const char *name,
720 char type, u64 start)
721 {
722 struct symbol *sym;
723 struct dso *dso = arg;
724 struct rb_root_cached *root = &dso->symbols;
725
726 if (!symbol_type__filter(type))
727 return 0;
728
729 /* Ignore local symbols for ARM modules */
730 if (name[0] == '$')
731 return 0;
732
733 /*
734 * module symbols are not sorted so we add all
735 * symbols, setting length to 0, and rely on
736 * symbols__fixup_end() to fix it up.
737 */
738 sym = symbol__new(start, 0, kallsyms2elf_binding(type), kallsyms2elf_type(type), name);
739 if (sym == NULL)
740 return -ENOMEM;
741 /*
742 * We will pass the symbols to the filter later, in
743 * map__split_kallsyms, when we have split the maps per module
744 */
745 __symbols__insert(root, sym, !strchr(name, '['));
746
747 return 0;
748 }
749
750 /*
751 * Loads the function entries in /proc/kallsyms into kernel_map->dso,
752 * so that we can in the next step set the symbol ->end address and then
753 * call kernel_maps__split_kallsyms.
754 */
dso__load_all_kallsyms(struct dso * dso,const char * filename)755 static int dso__load_all_kallsyms(struct dso *dso, const char *filename)
756 {
757 return kallsyms__parse(filename, dso, map__process_kallsym_symbol);
758 }
759
maps__split_kallsyms_for_kcore(struct maps * kmaps,struct dso * dso)760 static int maps__split_kallsyms_for_kcore(struct maps *kmaps, struct dso *dso)
761 {
762 struct map *curr_map;
763 struct symbol *pos;
764 int count = 0;
765 struct rb_root_cached old_root = dso->symbols;
766 struct rb_root_cached *root = &dso->symbols;
767 struct rb_node *next = rb_first_cached(root);
768
769 if (!kmaps)
770 return -1;
771
772 *root = RB_ROOT_CACHED;
773
774 while (next) {
775 char *module;
776
777 pos = rb_entry(next, struct symbol, rb_node);
778 next = rb_next(&pos->rb_node);
779
780 rb_erase_cached(&pos->rb_node, &old_root);
781 RB_CLEAR_NODE(&pos->rb_node);
782 module = strchr(pos->name, '\t');
783 if (module)
784 *module = '\0';
785
786 curr_map = maps__find(kmaps, pos->start);
787
788 if (!curr_map) {
789 symbol__delete(pos);
790 continue;
791 }
792
793 pos->start -= curr_map->start - curr_map->pgoff;
794 if (pos->end > curr_map->end)
795 pos->end = curr_map->end;
796 if (pos->end)
797 pos->end -= curr_map->start - curr_map->pgoff;
798 symbols__insert(&curr_map->dso->symbols, pos);
799 ++count;
800 }
801
802 /* Symbols have been adjusted */
803 dso->adjust_symbols = 1;
804
805 return count;
806 }
807
808 /*
809 * Split the symbols into maps, making sure there are no overlaps, i.e. the
810 * kernel range is broken in several maps, named [kernel].N, as we don't have
811 * the original ELF section names vmlinux have.
812 */
maps__split_kallsyms(struct maps * kmaps,struct dso * dso,u64 delta,struct map * initial_map)813 static int maps__split_kallsyms(struct maps *kmaps, struct dso *dso, u64 delta,
814 struct map *initial_map)
815 {
816 struct machine *machine;
817 struct map *curr_map = initial_map;
818 struct symbol *pos;
819 int count = 0, moved = 0;
820 struct rb_root_cached *root = &dso->symbols;
821 struct rb_node *next = rb_first_cached(root);
822 int kernel_range = 0;
823 bool x86_64;
824
825 if (!kmaps)
826 return -1;
827
828 machine = kmaps->machine;
829
830 x86_64 = machine__is(machine, "x86_64");
831
832 while (next) {
833 char *module;
834
835 pos = rb_entry(next, struct symbol, rb_node);
836 next = rb_next(&pos->rb_node);
837
838 module = strchr(pos->name, '\t');
839 if (module) {
840 if (!symbol_conf.use_modules)
841 goto discard_symbol;
842
843 *module++ = '\0';
844
845 if (strcmp(curr_map->dso->short_name, module)) {
846 if (curr_map != initial_map &&
847 dso->kernel == DSO_SPACE__KERNEL_GUEST &&
848 machine__is_default_guest(machine)) {
849 /*
850 * We assume all symbols of a module are
851 * continuous in * kallsyms, so curr_map
852 * points to a module and all its
853 * symbols are in its kmap. Mark it as
854 * loaded.
855 */
856 dso__set_loaded(curr_map->dso);
857 }
858
859 curr_map = maps__find_by_name(kmaps, module);
860 if (curr_map == NULL) {
861 pr_debug("%s/proc/{kallsyms,modules} "
862 "inconsistency while looking "
863 "for \"%s\" module!\n",
864 machine->root_dir, module);
865 curr_map = initial_map;
866 goto discard_symbol;
867 }
868
869 if (curr_map->dso->loaded &&
870 !machine__is_default_guest(machine))
871 goto discard_symbol;
872 }
873 /*
874 * So that we look just like we get from .ko files,
875 * i.e. not prelinked, relative to initial_map->start.
876 */
877 pos->start = curr_map->map_ip(curr_map, pos->start);
878 pos->end = curr_map->map_ip(curr_map, pos->end);
879 } else if (x86_64 && is_entry_trampoline(pos->name)) {
880 /*
881 * These symbols are not needed anymore since the
882 * trampoline maps refer to the text section and it's
883 * symbols instead. Avoid having to deal with
884 * relocations, and the assumption that the first symbol
885 * is the start of kernel text, by simply removing the
886 * symbols at this point.
887 */
888 goto discard_symbol;
889 } else if (curr_map != initial_map) {
890 char dso_name[PATH_MAX];
891 struct dso *ndso;
892
893 if (delta) {
894 /* Kernel was relocated at boot time */
895 pos->start -= delta;
896 pos->end -= delta;
897 }
898
899 if (count == 0) {
900 curr_map = initial_map;
901 goto add_symbol;
902 }
903
904 if (dso->kernel == DSO_SPACE__KERNEL_GUEST)
905 snprintf(dso_name, sizeof(dso_name),
906 "[guest.kernel].%d",
907 kernel_range++);
908 else
909 snprintf(dso_name, sizeof(dso_name),
910 "[kernel].%d",
911 kernel_range++);
912
913 ndso = dso__new(dso_name);
914 if (ndso == NULL)
915 return -1;
916
917 ndso->kernel = dso->kernel;
918
919 curr_map = map__new2(pos->start, ndso);
920 if (curr_map == NULL) {
921 dso__put(ndso);
922 return -1;
923 }
924
925 curr_map->map_ip = curr_map->unmap_ip = identity__map_ip;
926 maps__insert(kmaps, curr_map);
927 ++kernel_range;
928 } else if (delta) {
929 /* Kernel was relocated at boot time */
930 pos->start -= delta;
931 pos->end -= delta;
932 }
933 add_symbol:
934 if (curr_map != initial_map) {
935 rb_erase_cached(&pos->rb_node, root);
936 symbols__insert(&curr_map->dso->symbols, pos);
937 ++moved;
938 } else
939 ++count;
940
941 continue;
942 discard_symbol:
943 rb_erase_cached(&pos->rb_node, root);
944 symbol__delete(pos);
945 }
946
947 if (curr_map != initial_map &&
948 dso->kernel == DSO_SPACE__KERNEL_GUEST &&
949 machine__is_default_guest(kmaps->machine)) {
950 dso__set_loaded(curr_map->dso);
951 }
952
953 return count + moved;
954 }
955
symbol__restricted_filename(const char * filename,const char * restricted_filename)956 bool symbol__restricted_filename(const char *filename,
957 const char *restricted_filename)
958 {
959 bool restricted = false;
960
961 if (symbol_conf.kptr_restrict) {
962 char *r = realpath(filename, NULL);
963
964 if (r != NULL) {
965 restricted = strcmp(r, restricted_filename) == 0;
966 free(r);
967 return restricted;
968 }
969 }
970
971 return restricted;
972 }
973
974 struct module_info {
975 struct rb_node rb_node;
976 char *name;
977 u64 start;
978 };
979
add_module(struct module_info * mi,struct rb_root * modules)980 static void add_module(struct module_info *mi, struct rb_root *modules)
981 {
982 struct rb_node **p = &modules->rb_node;
983 struct rb_node *parent = NULL;
984 struct module_info *m;
985
986 while (*p != NULL) {
987 parent = *p;
988 m = rb_entry(parent, struct module_info, rb_node);
989 if (strcmp(mi->name, m->name) < 0)
990 p = &(*p)->rb_left;
991 else
992 p = &(*p)->rb_right;
993 }
994 rb_link_node(&mi->rb_node, parent, p);
995 rb_insert_color(&mi->rb_node, modules);
996 }
997
delete_modules(struct rb_root * modules)998 static void delete_modules(struct rb_root *modules)
999 {
1000 struct module_info *mi;
1001 struct rb_node *next = rb_first(modules);
1002
1003 while (next) {
1004 mi = rb_entry(next, struct module_info, rb_node);
1005 next = rb_next(&mi->rb_node);
1006 rb_erase(&mi->rb_node, modules);
1007 zfree(&mi->name);
1008 free(mi);
1009 }
1010 }
1011
find_module(const char * name,struct rb_root * modules)1012 static struct module_info *find_module(const char *name,
1013 struct rb_root *modules)
1014 {
1015 struct rb_node *n = modules->rb_node;
1016
1017 while (n) {
1018 struct module_info *m;
1019 int cmp;
1020
1021 m = rb_entry(n, struct module_info, rb_node);
1022 cmp = strcmp(name, m->name);
1023 if (cmp < 0)
1024 n = n->rb_left;
1025 else if (cmp > 0)
1026 n = n->rb_right;
1027 else
1028 return m;
1029 }
1030
1031 return NULL;
1032 }
1033
__read_proc_modules(void * arg,const char * name,u64 start,u64 size __maybe_unused)1034 static int __read_proc_modules(void *arg, const char *name, u64 start,
1035 u64 size __maybe_unused)
1036 {
1037 struct rb_root *modules = arg;
1038 struct module_info *mi;
1039
1040 mi = zalloc(sizeof(struct module_info));
1041 if (!mi)
1042 return -ENOMEM;
1043
1044 mi->name = strdup(name);
1045 mi->start = start;
1046
1047 if (!mi->name) {
1048 free(mi);
1049 return -ENOMEM;
1050 }
1051
1052 add_module(mi, modules);
1053
1054 return 0;
1055 }
1056
read_proc_modules(const char * filename,struct rb_root * modules)1057 static int read_proc_modules(const char *filename, struct rb_root *modules)
1058 {
1059 if (symbol__restricted_filename(filename, "/proc/modules"))
1060 return -1;
1061
1062 if (modules__parse(filename, modules, __read_proc_modules)) {
1063 delete_modules(modules);
1064 return -1;
1065 }
1066
1067 return 0;
1068 }
1069
compare_proc_modules(const char * from,const char * to)1070 int compare_proc_modules(const char *from, const char *to)
1071 {
1072 struct rb_root from_modules = RB_ROOT;
1073 struct rb_root to_modules = RB_ROOT;
1074 struct rb_node *from_node, *to_node;
1075 struct module_info *from_m, *to_m;
1076 int ret = -1;
1077
1078 if (read_proc_modules(from, &from_modules))
1079 return -1;
1080
1081 if (read_proc_modules(to, &to_modules))
1082 goto out_delete_from;
1083
1084 from_node = rb_first(&from_modules);
1085 to_node = rb_first(&to_modules);
1086 while (from_node) {
1087 if (!to_node)
1088 break;
1089
1090 from_m = rb_entry(from_node, struct module_info, rb_node);
1091 to_m = rb_entry(to_node, struct module_info, rb_node);
1092
1093 if (from_m->start != to_m->start ||
1094 strcmp(from_m->name, to_m->name))
1095 break;
1096
1097 from_node = rb_next(from_node);
1098 to_node = rb_next(to_node);
1099 }
1100
1101 if (!from_node && !to_node)
1102 ret = 0;
1103
1104 delete_modules(&to_modules);
1105 out_delete_from:
1106 delete_modules(&from_modules);
1107
1108 return ret;
1109 }
1110
do_validate_kcore_modules(const char * filename,struct maps * kmaps)1111 static int do_validate_kcore_modules(const char *filename, struct maps *kmaps)
1112 {
1113 struct rb_root modules = RB_ROOT;
1114 struct map *old_map;
1115 int err;
1116
1117 err = read_proc_modules(filename, &modules);
1118 if (err)
1119 return err;
1120
1121 maps__for_each_entry(kmaps, old_map) {
1122 struct module_info *mi;
1123
1124 if (!__map__is_kmodule(old_map)) {
1125 continue;
1126 }
1127
1128 /* Module must be in memory at the same address */
1129 mi = find_module(old_map->dso->short_name, &modules);
1130 if (!mi || mi->start != old_map->start) {
1131 err = -EINVAL;
1132 goto out;
1133 }
1134 }
1135 out:
1136 delete_modules(&modules);
1137 return err;
1138 }
1139
1140 /*
1141 * If kallsyms is referenced by name then we look for filename in the same
1142 * directory.
1143 */
filename_from_kallsyms_filename(char * filename,const char * base_name,const char * kallsyms_filename)1144 static bool filename_from_kallsyms_filename(char *filename,
1145 const char *base_name,
1146 const char *kallsyms_filename)
1147 {
1148 char *name;
1149
1150 strcpy(filename, kallsyms_filename);
1151 name = strrchr(filename, '/');
1152 if (!name)
1153 return false;
1154
1155 name += 1;
1156
1157 if (!strcmp(name, "kallsyms")) {
1158 strcpy(name, base_name);
1159 return true;
1160 }
1161
1162 return false;
1163 }
1164
validate_kcore_modules(const char * kallsyms_filename,struct map * map)1165 static int validate_kcore_modules(const char *kallsyms_filename,
1166 struct map *map)
1167 {
1168 struct maps *kmaps = map__kmaps(map);
1169 char modules_filename[PATH_MAX];
1170
1171 if (!kmaps)
1172 return -EINVAL;
1173
1174 if (!filename_from_kallsyms_filename(modules_filename, "modules",
1175 kallsyms_filename))
1176 return -EINVAL;
1177
1178 if (do_validate_kcore_modules(modules_filename, kmaps))
1179 return -EINVAL;
1180
1181 return 0;
1182 }
1183
validate_kcore_addresses(const char * kallsyms_filename,struct map * map)1184 static int validate_kcore_addresses(const char *kallsyms_filename,
1185 struct map *map)
1186 {
1187 struct kmap *kmap = map__kmap(map);
1188
1189 if (!kmap)
1190 return -EINVAL;
1191
1192 if (kmap->ref_reloc_sym && kmap->ref_reloc_sym->name) {
1193 u64 start;
1194
1195 if (kallsyms__get_function_start(kallsyms_filename,
1196 kmap->ref_reloc_sym->name, &start))
1197 return -ENOENT;
1198 if (start != kmap->ref_reloc_sym->addr)
1199 return -EINVAL;
1200 }
1201
1202 return validate_kcore_modules(kallsyms_filename, map);
1203 }
1204
1205 struct kcore_mapfn_data {
1206 struct dso *dso;
1207 struct list_head maps;
1208 };
1209
kcore_mapfn(u64 start,u64 len,u64 pgoff,void * data)1210 static int kcore_mapfn(u64 start, u64 len, u64 pgoff, void *data)
1211 {
1212 struct kcore_mapfn_data *md = data;
1213 struct map *map;
1214
1215 map = map__new2(start, md->dso);
1216 if (map == NULL)
1217 return -ENOMEM;
1218
1219 map->end = map->start + len;
1220 map->pgoff = pgoff;
1221
1222 list_add(&map->node, &md->maps);
1223
1224 return 0;
1225 }
1226
1227 /*
1228 * Merges map into maps by splitting the new map within the existing map
1229 * regions.
1230 */
maps__merge_in(struct maps * kmaps,struct map * new_map)1231 int maps__merge_in(struct maps *kmaps, struct map *new_map)
1232 {
1233 struct map *old_map;
1234 LIST_HEAD(merged);
1235
1236 maps__for_each_entry(kmaps, old_map) {
1237 /* no overload with this one */
1238 if (new_map->end < old_map->start ||
1239 new_map->start >= old_map->end)
1240 continue;
1241
1242 if (new_map->start < old_map->start) {
1243 /*
1244 * |new......
1245 * |old....
1246 */
1247 if (new_map->end < old_map->end) {
1248 /*
1249 * |new......| -> |new..|
1250 * |old....| -> |old....|
1251 */
1252 new_map->end = old_map->start;
1253 } else {
1254 /*
1255 * |new.............| -> |new..| |new..|
1256 * |old....| -> |old....|
1257 */
1258 struct map *m = map__clone(new_map);
1259
1260 if (!m)
1261 return -ENOMEM;
1262
1263 m->end = old_map->start;
1264 list_add_tail(&m->node, &merged);
1265 new_map->pgoff += old_map->end - new_map->start;
1266 new_map->start = old_map->end;
1267 }
1268 } else {
1269 /*
1270 * |new......
1271 * |old....
1272 */
1273 if (new_map->end < old_map->end) {
1274 /*
1275 * |new..| -> x
1276 * |old.........| -> |old.........|
1277 */
1278 map__put(new_map);
1279 new_map = NULL;
1280 break;
1281 } else {
1282 /*
1283 * |new......| -> |new...|
1284 * |old....| -> |old....|
1285 */
1286 new_map->pgoff += old_map->end - new_map->start;
1287 new_map->start = old_map->end;
1288 }
1289 }
1290 }
1291
1292 while (!list_empty(&merged)) {
1293 old_map = list_entry(merged.next, struct map, node);
1294 list_del_init(&old_map->node);
1295 maps__insert(kmaps, old_map);
1296 map__put(old_map);
1297 }
1298
1299 if (new_map) {
1300 maps__insert(kmaps, new_map);
1301 map__put(new_map);
1302 }
1303 return 0;
1304 }
1305
dso__load_kcore(struct dso * dso,struct map * map,const char * kallsyms_filename)1306 static int dso__load_kcore(struct dso *dso, struct map *map,
1307 const char *kallsyms_filename)
1308 {
1309 struct maps *kmaps = map__kmaps(map);
1310 struct kcore_mapfn_data md;
1311 struct map *old_map, *new_map, *replacement_map = NULL, *next;
1312 struct machine *machine;
1313 bool is_64_bit;
1314 int err, fd;
1315 char kcore_filename[PATH_MAX];
1316 u64 stext;
1317
1318 if (!kmaps)
1319 return -EINVAL;
1320
1321 machine = kmaps->machine;
1322
1323 /* This function requires that the map is the kernel map */
1324 if (!__map__is_kernel(map))
1325 return -EINVAL;
1326
1327 if (!filename_from_kallsyms_filename(kcore_filename, "kcore",
1328 kallsyms_filename))
1329 return -EINVAL;
1330
1331 /* Modules and kernel must be present at their original addresses */
1332 if (validate_kcore_addresses(kallsyms_filename, map))
1333 return -EINVAL;
1334
1335 md.dso = dso;
1336 INIT_LIST_HEAD(&md.maps);
1337
1338 fd = open(kcore_filename, O_RDONLY);
1339 if (fd < 0) {
1340 pr_debug("Failed to open %s. Note /proc/kcore requires CAP_SYS_RAWIO capability to access.\n",
1341 kcore_filename);
1342 return -EINVAL;
1343 }
1344
1345 /* Read new maps into temporary lists */
1346 err = file__read_maps(fd, map->prot & PROT_EXEC, kcore_mapfn, &md,
1347 &is_64_bit);
1348 if (err)
1349 goto out_err;
1350 dso->is_64_bit = is_64_bit;
1351
1352 if (list_empty(&md.maps)) {
1353 err = -EINVAL;
1354 goto out_err;
1355 }
1356
1357 /* Remove old maps */
1358 maps__for_each_entry_safe(kmaps, old_map, next) {
1359 /*
1360 * We need to preserve eBPF maps even if they are
1361 * covered by kcore, because we need to access
1362 * eBPF dso for source data.
1363 */
1364 if (old_map != map && !__map__is_bpf_prog(old_map))
1365 maps__remove(kmaps, old_map);
1366 }
1367 machine->trampolines_mapped = false;
1368
1369 /* Find the kernel map using the '_stext' symbol */
1370 if (!kallsyms__get_function_start(kallsyms_filename, "_stext", &stext)) {
1371 list_for_each_entry(new_map, &md.maps, node) {
1372 if (stext >= new_map->start && stext < new_map->end) {
1373 replacement_map = new_map;
1374 break;
1375 }
1376 }
1377 }
1378
1379 if (!replacement_map)
1380 replacement_map = list_entry(md.maps.next, struct map, node);
1381
1382 /* Add new maps */
1383 while (!list_empty(&md.maps)) {
1384 new_map = list_entry(md.maps.next, struct map, node);
1385 list_del_init(&new_map->node);
1386 if (new_map == replacement_map) {
1387 map->start = new_map->start;
1388 map->end = new_map->end;
1389 map->pgoff = new_map->pgoff;
1390 map->map_ip = new_map->map_ip;
1391 map->unmap_ip = new_map->unmap_ip;
1392 /* Ensure maps are correctly ordered */
1393 map__get(map);
1394 maps__remove(kmaps, map);
1395 maps__insert(kmaps, map);
1396 map__put(map);
1397 map__put(new_map);
1398 } else {
1399 /*
1400 * Merge kcore map into existing maps,
1401 * and ensure that current maps (eBPF)
1402 * stay intact.
1403 */
1404 if (maps__merge_in(kmaps, new_map))
1405 goto out_err;
1406 }
1407 }
1408
1409 if (machine__is(machine, "x86_64")) {
1410 u64 addr;
1411
1412 /*
1413 * If one of the corresponding symbols is there, assume the
1414 * entry trampoline maps are too.
1415 */
1416 if (!kallsyms__get_function_start(kallsyms_filename,
1417 ENTRY_TRAMPOLINE_NAME,
1418 &addr))
1419 machine->trampolines_mapped = true;
1420 }
1421
1422 /*
1423 * Set the data type and long name so that kcore can be read via
1424 * dso__data_read_addr().
1425 */
1426 if (dso->kernel == DSO_SPACE__KERNEL_GUEST)
1427 dso->binary_type = DSO_BINARY_TYPE__GUEST_KCORE;
1428 else
1429 dso->binary_type = DSO_BINARY_TYPE__KCORE;
1430 dso__set_long_name(dso, strdup(kcore_filename), true);
1431
1432 close(fd);
1433
1434 if (map->prot & PROT_EXEC)
1435 pr_debug("Using %s for kernel object code\n", kcore_filename);
1436 else
1437 pr_debug("Using %s for kernel data\n", kcore_filename);
1438
1439 return 0;
1440
1441 out_err:
1442 while (!list_empty(&md.maps)) {
1443 map = list_entry(md.maps.next, struct map, node);
1444 list_del_init(&map->node);
1445 map__put(map);
1446 }
1447 close(fd);
1448 return -EINVAL;
1449 }
1450
1451 /*
1452 * If the kernel is relocated at boot time, kallsyms won't match. Compute the
1453 * delta based on the relocation reference symbol.
1454 */
kallsyms__delta(struct kmap * kmap,const char * filename,u64 * delta)1455 static int kallsyms__delta(struct kmap *kmap, const char *filename, u64 *delta)
1456 {
1457 u64 addr;
1458
1459 if (!kmap->ref_reloc_sym || !kmap->ref_reloc_sym->name)
1460 return 0;
1461
1462 if (kallsyms__get_function_start(filename, kmap->ref_reloc_sym->name, &addr))
1463 return -1;
1464
1465 *delta = addr - kmap->ref_reloc_sym->addr;
1466 return 0;
1467 }
1468
__dso__load_kallsyms(struct dso * dso,const char * filename,struct map * map,bool no_kcore)1469 int __dso__load_kallsyms(struct dso *dso, const char *filename,
1470 struct map *map, bool no_kcore)
1471 {
1472 struct kmap *kmap = map__kmap(map);
1473 u64 delta = 0;
1474
1475 if (symbol__restricted_filename(filename, "/proc/kallsyms"))
1476 return -1;
1477
1478 if (!kmap || !kmap->kmaps)
1479 return -1;
1480
1481 if (dso__load_all_kallsyms(dso, filename) < 0)
1482 return -1;
1483
1484 if (kallsyms__delta(kmap, filename, &delta))
1485 return -1;
1486
1487 symbols__fixup_end(&dso->symbols, true);
1488 symbols__fixup_duplicate(&dso->symbols);
1489
1490 if (dso->kernel == DSO_SPACE__KERNEL_GUEST)
1491 dso->symtab_type = DSO_BINARY_TYPE__GUEST_KALLSYMS;
1492 else
1493 dso->symtab_type = DSO_BINARY_TYPE__KALLSYMS;
1494
1495 if (!no_kcore && !dso__load_kcore(dso, map, filename))
1496 return maps__split_kallsyms_for_kcore(kmap->kmaps, dso);
1497 else
1498 return maps__split_kallsyms(kmap->kmaps, dso, delta, map);
1499 }
1500
dso__load_kallsyms(struct dso * dso,const char * filename,struct map * map)1501 int dso__load_kallsyms(struct dso *dso, const char *filename,
1502 struct map *map)
1503 {
1504 return __dso__load_kallsyms(dso, filename, map, false);
1505 }
1506
dso__load_perf_map(const char * map_path,struct dso * dso)1507 static int dso__load_perf_map(const char *map_path, struct dso *dso)
1508 {
1509 char *line = NULL;
1510 size_t n;
1511 FILE *file;
1512 int nr_syms = 0;
1513
1514 file = fopen(map_path, "r");
1515 if (file == NULL)
1516 goto out_failure;
1517
1518 while (!feof(file)) {
1519 u64 start, size;
1520 struct symbol *sym;
1521 int line_len, len;
1522
1523 line_len = getline(&line, &n, file);
1524 if (line_len < 0)
1525 break;
1526
1527 if (!line)
1528 goto out_failure;
1529
1530 line[--line_len] = '\0'; /* \n */
1531
1532 len = hex2u64(line, &start);
1533
1534 len++;
1535 if (len + 2 >= line_len)
1536 continue;
1537
1538 len += hex2u64(line + len, &size);
1539
1540 len++;
1541 if (len + 2 >= line_len)
1542 continue;
1543
1544 sym = symbol__new(start, size, STB_GLOBAL, STT_FUNC, line + len);
1545
1546 if (sym == NULL)
1547 goto out_delete_line;
1548
1549 symbols__insert(&dso->symbols, sym);
1550 nr_syms++;
1551 }
1552
1553 free(line);
1554 fclose(file);
1555
1556 return nr_syms;
1557
1558 out_delete_line:
1559 free(line);
1560 out_failure:
1561 return -1;
1562 }
1563
1564 #ifdef HAVE_LIBBFD_SUPPORT
1565 #define PACKAGE 'perf'
1566 #include <bfd.h>
1567
bfd_symbols__cmpvalue(const void * a,const void * b)1568 static int bfd_symbols__cmpvalue(const void *a, const void *b)
1569 {
1570 const asymbol *as = *(const asymbol **)a, *bs = *(const asymbol **)b;
1571
1572 if (bfd_asymbol_value(as) != bfd_asymbol_value(bs))
1573 return bfd_asymbol_value(as) - bfd_asymbol_value(bs);
1574
1575 return bfd_asymbol_name(as)[0] - bfd_asymbol_name(bs)[0];
1576 }
1577
bfd2elf_binding(asymbol * symbol)1578 static int bfd2elf_binding(asymbol *symbol)
1579 {
1580 if (symbol->flags & BSF_WEAK)
1581 return STB_WEAK;
1582 if (symbol->flags & BSF_GLOBAL)
1583 return STB_GLOBAL;
1584 if (symbol->flags & BSF_LOCAL)
1585 return STB_LOCAL;
1586 return -1;
1587 }
1588
dso__load_bfd_symbols(struct dso * dso,const char * debugfile)1589 int dso__load_bfd_symbols(struct dso *dso, const char *debugfile)
1590 {
1591 int err = -1;
1592 long symbols_size, symbols_count, i;
1593 asection *section;
1594 asymbol **symbols, *sym;
1595 struct symbol *symbol;
1596 bfd *abfd;
1597 u64 start, len;
1598
1599 abfd = bfd_openr(debugfile, NULL);
1600 if (!abfd)
1601 return -1;
1602
1603 if (!bfd_check_format(abfd, bfd_object)) {
1604 pr_debug2("%s: cannot read %s bfd file.\n", __func__,
1605 dso->long_name);
1606 goto out_close;
1607 }
1608
1609 if (bfd_get_flavour(abfd) == bfd_target_elf_flavour)
1610 goto out_close;
1611
1612 symbols_size = bfd_get_symtab_upper_bound(abfd);
1613 if (symbols_size == 0) {
1614 bfd_close(abfd);
1615 return 0;
1616 }
1617
1618 if (symbols_size < 0)
1619 goto out_close;
1620
1621 symbols = malloc(symbols_size);
1622 if (!symbols)
1623 goto out_close;
1624
1625 symbols_count = bfd_canonicalize_symtab(abfd, symbols);
1626 if (symbols_count < 0)
1627 goto out_free;
1628
1629 section = bfd_get_section_by_name(abfd, ".text");
1630 if (section) {
1631 for (i = 0; i < symbols_count; ++i) {
1632 if (!strcmp(bfd_asymbol_name(symbols[i]), "__ImageBase") ||
1633 !strcmp(bfd_asymbol_name(symbols[i]), "__image_base__"))
1634 break;
1635 }
1636 if (i < symbols_count) {
1637 /* PE symbols can only have 4 bytes, so use .text high bits */
1638 dso->text_offset = section->vma - (u32)section->vma;
1639 dso->text_offset += (u32)bfd_asymbol_value(symbols[i]);
1640 } else {
1641 dso->text_offset = section->vma - section->filepos;
1642 }
1643 }
1644
1645 qsort(symbols, symbols_count, sizeof(asymbol *), bfd_symbols__cmpvalue);
1646
1647 #ifdef bfd_get_section
1648 #define bfd_asymbol_section bfd_get_section
1649 #endif
1650 for (i = 0; i < symbols_count; ++i) {
1651 sym = symbols[i];
1652 section = bfd_asymbol_section(sym);
1653 if (bfd2elf_binding(sym) < 0)
1654 continue;
1655
1656 while (i + 1 < symbols_count &&
1657 bfd_asymbol_section(symbols[i + 1]) == section &&
1658 bfd2elf_binding(symbols[i + 1]) < 0)
1659 i++;
1660
1661 if (i + 1 < symbols_count &&
1662 bfd_asymbol_section(symbols[i + 1]) == section)
1663 len = symbols[i + 1]->value - sym->value;
1664 else
1665 len = section->size - sym->value;
1666
1667 start = bfd_asymbol_value(sym) - dso->text_offset;
1668 symbol = symbol__new(start, len, bfd2elf_binding(sym), STT_FUNC,
1669 bfd_asymbol_name(sym));
1670 if (!symbol)
1671 goto out_free;
1672
1673 symbols__insert(&dso->symbols, symbol);
1674 }
1675 #ifdef bfd_get_section
1676 #undef bfd_asymbol_section
1677 #endif
1678
1679 symbols__fixup_end(&dso->symbols, false);
1680 symbols__fixup_duplicate(&dso->symbols);
1681 dso->adjust_symbols = 1;
1682
1683 err = 0;
1684 out_free:
1685 free(symbols);
1686 out_close:
1687 bfd_close(abfd);
1688 return err;
1689 }
1690 #endif
1691
dso__is_compatible_symtab_type(struct dso * dso,bool kmod,enum dso_binary_type type)1692 static bool dso__is_compatible_symtab_type(struct dso *dso, bool kmod,
1693 enum dso_binary_type type)
1694 {
1695 switch (type) {
1696 case DSO_BINARY_TYPE__JAVA_JIT:
1697 case DSO_BINARY_TYPE__DEBUGLINK:
1698 case DSO_BINARY_TYPE__SYSTEM_PATH_DSO:
1699 case DSO_BINARY_TYPE__FEDORA_DEBUGINFO:
1700 case DSO_BINARY_TYPE__UBUNTU_DEBUGINFO:
1701 case DSO_BINARY_TYPE__MIXEDUP_UBUNTU_DEBUGINFO:
1702 case DSO_BINARY_TYPE__BUILDID_DEBUGINFO:
1703 case DSO_BINARY_TYPE__OPENEMBEDDED_DEBUGINFO:
1704 return !kmod && dso->kernel == DSO_SPACE__USER;
1705
1706 case DSO_BINARY_TYPE__KALLSYMS:
1707 case DSO_BINARY_TYPE__VMLINUX:
1708 case DSO_BINARY_TYPE__KCORE:
1709 return dso->kernel == DSO_SPACE__KERNEL;
1710
1711 case DSO_BINARY_TYPE__GUEST_KALLSYMS:
1712 case DSO_BINARY_TYPE__GUEST_VMLINUX:
1713 case DSO_BINARY_TYPE__GUEST_KCORE:
1714 return dso->kernel == DSO_SPACE__KERNEL_GUEST;
1715
1716 case DSO_BINARY_TYPE__GUEST_KMODULE:
1717 case DSO_BINARY_TYPE__GUEST_KMODULE_COMP:
1718 case DSO_BINARY_TYPE__SYSTEM_PATH_KMODULE:
1719 case DSO_BINARY_TYPE__SYSTEM_PATH_KMODULE_COMP:
1720 /*
1721 * kernel modules know their symtab type - it's set when
1722 * creating a module dso in machine__addnew_module_map().
1723 */
1724 return kmod && dso->symtab_type == type;
1725
1726 case DSO_BINARY_TYPE__BUILD_ID_CACHE:
1727 case DSO_BINARY_TYPE__BUILD_ID_CACHE_DEBUGINFO:
1728 return true;
1729
1730 case DSO_BINARY_TYPE__BPF_PROG_INFO:
1731 case DSO_BINARY_TYPE__BPF_IMAGE:
1732 case DSO_BINARY_TYPE__OOL:
1733 case DSO_BINARY_TYPE__NOT_FOUND:
1734 default:
1735 return false;
1736 }
1737 }
1738
1739 /* Checks for the existence of the perf-<pid>.map file in two different
1740 * locations. First, if the process is a separate mount namespace, check in
1741 * that namespace using the pid of the innermost pid namespace. If's not in a
1742 * namespace, or the file can't be found there, try in the mount namespace of
1743 * the tracing process using our view of its pid.
1744 */
dso__find_perf_map(char * filebuf,size_t bufsz,struct nsinfo ** nsip)1745 static int dso__find_perf_map(char *filebuf, size_t bufsz,
1746 struct nsinfo **nsip)
1747 {
1748 struct nscookie nsc;
1749 struct nsinfo *nsi;
1750 struct nsinfo *nnsi;
1751 int rc = -1;
1752
1753 nsi = *nsip;
1754
1755 if (nsinfo__need_setns(nsi)) {
1756 snprintf(filebuf, bufsz, "/tmp/perf-%d.map", nsinfo__nstgid(nsi));
1757 nsinfo__mountns_enter(nsi, &nsc);
1758 rc = access(filebuf, R_OK);
1759 nsinfo__mountns_exit(&nsc);
1760 if (rc == 0)
1761 return rc;
1762 }
1763
1764 nnsi = nsinfo__copy(nsi);
1765 if (nnsi) {
1766 nsinfo__put(nsi);
1767
1768 nsinfo__clear_need_setns(nnsi);
1769 snprintf(filebuf, bufsz, "/tmp/perf-%d.map", nsinfo__tgid(nnsi));
1770 *nsip = nnsi;
1771 rc = 0;
1772 }
1773
1774 return rc;
1775 }
1776
dso__load(struct dso * dso,struct map * map)1777 int dso__load(struct dso *dso, struct map *map)
1778 {
1779 char *name;
1780 int ret = -1;
1781 u_int i;
1782 struct machine *machine = NULL;
1783 char *root_dir = (char *) "";
1784 int ss_pos = 0;
1785 struct symsrc ss_[2];
1786 struct symsrc *syms_ss = NULL, *runtime_ss = NULL;
1787 bool kmod;
1788 bool perfmap;
1789 struct build_id bid;
1790 struct nscookie nsc;
1791 char newmapname[PATH_MAX];
1792 const char *map_path = dso->long_name;
1793
1794 mutex_lock(&dso->lock);
1795 perfmap = strncmp(dso->name, "/tmp/perf-", 10) == 0;
1796 if (perfmap) {
1797 if (dso->nsinfo && (dso__find_perf_map(newmapname,
1798 sizeof(newmapname), &dso->nsinfo) == 0)) {
1799 map_path = newmapname;
1800 }
1801 }
1802
1803 nsinfo__mountns_enter(dso->nsinfo, &nsc);
1804
1805 /* check again under the dso->lock */
1806 if (dso__loaded(dso)) {
1807 ret = 1;
1808 goto out;
1809 }
1810
1811 kmod = dso->symtab_type == DSO_BINARY_TYPE__SYSTEM_PATH_KMODULE ||
1812 dso->symtab_type == DSO_BINARY_TYPE__SYSTEM_PATH_KMODULE_COMP ||
1813 dso->symtab_type == DSO_BINARY_TYPE__GUEST_KMODULE ||
1814 dso->symtab_type == DSO_BINARY_TYPE__GUEST_KMODULE_COMP;
1815
1816 if (dso->kernel && !kmod) {
1817 if (dso->kernel == DSO_SPACE__KERNEL)
1818 ret = dso__load_kernel_sym(dso, map);
1819 else if (dso->kernel == DSO_SPACE__KERNEL_GUEST)
1820 ret = dso__load_guest_kernel_sym(dso, map);
1821
1822 machine = map__kmaps(map)->machine;
1823 if (machine__is(machine, "x86_64"))
1824 machine__map_x86_64_entry_trampolines(machine, dso);
1825 goto out;
1826 }
1827
1828 dso->adjust_symbols = 0;
1829
1830 if (perfmap) {
1831 ret = dso__load_perf_map(map_path, dso);
1832 dso->symtab_type = ret > 0 ? DSO_BINARY_TYPE__JAVA_JIT :
1833 DSO_BINARY_TYPE__NOT_FOUND;
1834 goto out;
1835 }
1836
1837 if (machine)
1838 root_dir = machine->root_dir;
1839
1840 name = malloc(PATH_MAX);
1841 if (!name)
1842 goto out;
1843
1844 /*
1845 * Read the build id if possible. This is required for
1846 * DSO_BINARY_TYPE__BUILDID_DEBUGINFO to work
1847 */
1848 if (!dso->has_build_id &&
1849 is_regular_file(dso->long_name)) {
1850 __symbol__join_symfs(name, PATH_MAX, dso->long_name);
1851 if (filename__read_build_id(name, &bid) > 0)
1852 dso__set_build_id(dso, &bid);
1853 }
1854
1855 /*
1856 * Iterate over candidate debug images.
1857 * Keep track of "interesting" ones (those which have a symtab, dynsym,
1858 * and/or opd section) for processing.
1859 */
1860 for (i = 0; i < DSO_BINARY_TYPE__SYMTAB_CNT; i++) {
1861 struct symsrc *ss = &ss_[ss_pos];
1862 bool next_slot = false;
1863 bool is_reg;
1864 bool nsexit;
1865 int bfdrc = -1;
1866 int sirc = -1;
1867
1868 enum dso_binary_type symtab_type = binary_type_symtab[i];
1869
1870 nsexit = (symtab_type == DSO_BINARY_TYPE__BUILD_ID_CACHE ||
1871 symtab_type == DSO_BINARY_TYPE__BUILD_ID_CACHE_DEBUGINFO);
1872
1873 if (!dso__is_compatible_symtab_type(dso, kmod, symtab_type))
1874 continue;
1875
1876 if (dso__read_binary_type_filename(dso, symtab_type,
1877 root_dir, name, PATH_MAX))
1878 continue;
1879
1880 if (nsexit)
1881 nsinfo__mountns_exit(&nsc);
1882
1883 is_reg = is_regular_file(name);
1884 if (!is_reg && errno == ENOENT && dso->nsinfo) {
1885 char *new_name = filename_with_chroot(dso->nsinfo->pid,
1886 name);
1887 if (new_name) {
1888 is_reg = is_regular_file(new_name);
1889 strlcpy(name, new_name, PATH_MAX);
1890 free(new_name);
1891 }
1892 }
1893
1894 #ifdef HAVE_LIBBFD_SUPPORT
1895 if (is_reg)
1896 bfdrc = dso__load_bfd_symbols(dso, name);
1897 #endif
1898 if (is_reg && bfdrc < 0)
1899 sirc = symsrc__init(ss, dso, name, symtab_type);
1900
1901 if (nsexit)
1902 nsinfo__mountns_enter(dso->nsinfo, &nsc);
1903
1904 if (bfdrc == 0) {
1905 ret = 0;
1906 break;
1907 }
1908
1909 if (!is_reg || sirc < 0)
1910 continue;
1911
1912 if (!syms_ss && symsrc__has_symtab(ss)) {
1913 syms_ss = ss;
1914 next_slot = true;
1915 if (!dso->symsrc_filename)
1916 dso->symsrc_filename = strdup(name);
1917 }
1918
1919 if (!runtime_ss && symsrc__possibly_runtime(ss)) {
1920 runtime_ss = ss;
1921 next_slot = true;
1922 }
1923
1924 if (next_slot) {
1925 ss_pos++;
1926
1927 if (syms_ss && runtime_ss)
1928 break;
1929 } else {
1930 symsrc__destroy(ss);
1931 }
1932
1933 }
1934
1935 if (!runtime_ss && !syms_ss)
1936 goto out_free;
1937
1938 if (runtime_ss && !syms_ss) {
1939 syms_ss = runtime_ss;
1940 }
1941
1942 /* We'll have to hope for the best */
1943 if (!runtime_ss && syms_ss)
1944 runtime_ss = syms_ss;
1945
1946 if (syms_ss)
1947 ret = dso__load_sym(dso, map, syms_ss, runtime_ss, kmod);
1948 else
1949 ret = -1;
1950
1951 if (ret > 0) {
1952 int nr_plt;
1953
1954 nr_plt = dso__synthesize_plt_symbols(dso, runtime_ss);
1955 if (nr_plt > 0)
1956 ret += nr_plt;
1957 }
1958
1959 for (; ss_pos > 0; ss_pos--)
1960 symsrc__destroy(&ss_[ss_pos - 1]);
1961 out_free:
1962 free(name);
1963 if (ret < 0 && strstr(dso->name, " (deleted)") != NULL)
1964 ret = 0;
1965 out:
1966 dso__set_loaded(dso);
1967 mutex_unlock(&dso->lock);
1968 nsinfo__mountns_exit(&nsc);
1969
1970 return ret;
1971 }
1972
map__strcmp(const void * a,const void * b)1973 static int map__strcmp(const void *a, const void *b)
1974 {
1975 const struct map *ma = *(const struct map **)a, *mb = *(const struct map **)b;
1976 return strcmp(ma->dso->short_name, mb->dso->short_name);
1977 }
1978
map__strcmp_name(const void * name,const void * b)1979 static int map__strcmp_name(const void *name, const void *b)
1980 {
1981 const struct map *map = *(const struct map **)b;
1982 return strcmp(name, map->dso->short_name);
1983 }
1984
__maps__sort_by_name(struct maps * maps)1985 void __maps__sort_by_name(struct maps *maps)
1986 {
1987 qsort(maps->maps_by_name, maps->nr_maps, sizeof(struct map *), map__strcmp);
1988 }
1989
map__groups__sort_by_name_from_rbtree(struct maps * maps)1990 static int map__groups__sort_by_name_from_rbtree(struct maps *maps)
1991 {
1992 struct map *map;
1993 struct map **maps_by_name = realloc(maps->maps_by_name, maps->nr_maps * sizeof(map));
1994 int i = 0;
1995
1996 if (maps_by_name == NULL)
1997 return -1;
1998
1999 maps->maps_by_name = maps_by_name;
2000 maps->nr_maps_allocated = maps->nr_maps;
2001
2002 maps__for_each_entry(maps, map)
2003 maps_by_name[i++] = map;
2004
2005 __maps__sort_by_name(maps);
2006 return 0;
2007 }
2008
__maps__find_by_name(struct maps * maps,const char * name)2009 static struct map *__maps__find_by_name(struct maps *maps, const char *name)
2010 {
2011 struct map **mapp;
2012
2013 if (maps->maps_by_name == NULL &&
2014 map__groups__sort_by_name_from_rbtree(maps))
2015 return NULL;
2016
2017 mapp = bsearch(name, maps->maps_by_name, maps->nr_maps, sizeof(*mapp), map__strcmp_name);
2018 if (mapp)
2019 return *mapp;
2020 return NULL;
2021 }
2022
maps__find_by_name(struct maps * maps,const char * name)2023 struct map *maps__find_by_name(struct maps *maps, const char *name)
2024 {
2025 struct map *map;
2026
2027 down_read(&maps->lock);
2028
2029 if (maps->last_search_by_name && strcmp(maps->last_search_by_name->dso->short_name, name) == 0) {
2030 map = maps->last_search_by_name;
2031 goto out_unlock;
2032 }
2033 /*
2034 * If we have maps->maps_by_name, then the name isn't in the rbtree,
2035 * as maps->maps_by_name mirrors the rbtree when lookups by name are
2036 * made.
2037 */
2038 map = __maps__find_by_name(maps, name);
2039 if (map || maps->maps_by_name != NULL)
2040 goto out_unlock;
2041
2042 /* Fallback to traversing the rbtree... */
2043 maps__for_each_entry(maps, map)
2044 if (strcmp(map->dso->short_name, name) == 0) {
2045 maps->last_search_by_name = map;
2046 goto out_unlock;
2047 }
2048
2049 map = NULL;
2050
2051 out_unlock:
2052 up_read(&maps->lock);
2053 return map;
2054 }
2055
dso__load_vmlinux(struct dso * dso,struct map * map,const char * vmlinux,bool vmlinux_allocated)2056 int dso__load_vmlinux(struct dso *dso, struct map *map,
2057 const char *vmlinux, bool vmlinux_allocated)
2058 {
2059 int err = -1;
2060 struct symsrc ss;
2061 char symfs_vmlinux[PATH_MAX];
2062 enum dso_binary_type symtab_type;
2063
2064 if (vmlinux[0] == '/')
2065 snprintf(symfs_vmlinux, sizeof(symfs_vmlinux), "%s", vmlinux);
2066 else
2067 symbol__join_symfs(symfs_vmlinux, vmlinux);
2068
2069 if (dso->kernel == DSO_SPACE__KERNEL_GUEST)
2070 symtab_type = DSO_BINARY_TYPE__GUEST_VMLINUX;
2071 else
2072 symtab_type = DSO_BINARY_TYPE__VMLINUX;
2073
2074 if (symsrc__init(&ss, dso, symfs_vmlinux, symtab_type))
2075 return -1;
2076
2077 err = dso__load_sym(dso, map, &ss, &ss, 0);
2078 symsrc__destroy(&ss);
2079
2080 if (err > 0) {
2081 if (dso->kernel == DSO_SPACE__KERNEL_GUEST)
2082 dso->binary_type = DSO_BINARY_TYPE__GUEST_VMLINUX;
2083 else
2084 dso->binary_type = DSO_BINARY_TYPE__VMLINUX;
2085 dso__set_long_name(dso, vmlinux, vmlinux_allocated);
2086 dso__set_loaded(dso);
2087 pr_debug("Using %s for symbols\n", symfs_vmlinux);
2088 }
2089
2090 return err;
2091 }
2092
dso__load_vmlinux_path(struct dso * dso,struct map * map)2093 int dso__load_vmlinux_path(struct dso *dso, struct map *map)
2094 {
2095 int i, err = 0;
2096 char *filename = NULL;
2097
2098 pr_debug("Looking at the vmlinux_path (%d entries long)\n",
2099 vmlinux_path__nr_entries + 1);
2100
2101 for (i = 0; i < vmlinux_path__nr_entries; ++i) {
2102 err = dso__load_vmlinux(dso, map, vmlinux_path[i], false);
2103 if (err > 0)
2104 goto out;
2105 }
2106
2107 if (!symbol_conf.ignore_vmlinux_buildid)
2108 filename = dso__build_id_filename(dso, NULL, 0, false);
2109 if (filename != NULL) {
2110 err = dso__load_vmlinux(dso, map, filename, true);
2111 if (err > 0)
2112 goto out;
2113 free(filename);
2114 }
2115 out:
2116 return err;
2117 }
2118
visible_dir_filter(const char * name,struct dirent * d)2119 static bool visible_dir_filter(const char *name, struct dirent *d)
2120 {
2121 if (d->d_type != DT_DIR)
2122 return false;
2123 return lsdir_no_dot_filter(name, d);
2124 }
2125
find_matching_kcore(struct map * map,char * dir,size_t dir_sz)2126 static int find_matching_kcore(struct map *map, char *dir, size_t dir_sz)
2127 {
2128 char kallsyms_filename[PATH_MAX];
2129 int ret = -1;
2130 struct strlist *dirs;
2131 struct str_node *nd;
2132
2133 dirs = lsdir(dir, visible_dir_filter);
2134 if (!dirs)
2135 return -1;
2136
2137 strlist__for_each_entry(nd, dirs) {
2138 scnprintf(kallsyms_filename, sizeof(kallsyms_filename),
2139 "%s/%s/kallsyms", dir, nd->s);
2140 if (!validate_kcore_addresses(kallsyms_filename, map)) {
2141 strlcpy(dir, kallsyms_filename, dir_sz);
2142 ret = 0;
2143 break;
2144 }
2145 }
2146
2147 strlist__delete(dirs);
2148
2149 return ret;
2150 }
2151
2152 /*
2153 * Use open(O_RDONLY) to check readability directly instead of access(R_OK)
2154 * since access(R_OK) only checks with real UID/GID but open() use effective
2155 * UID/GID and actual capabilities (e.g. /proc/kcore requires CAP_SYS_RAWIO).
2156 */
filename__readable(const char * file)2157 static bool filename__readable(const char *file)
2158 {
2159 int fd = open(file, O_RDONLY);
2160 if (fd < 0)
2161 return false;
2162 close(fd);
2163 return true;
2164 }
2165
dso__find_kallsyms(struct dso * dso,struct map * map)2166 static char *dso__find_kallsyms(struct dso *dso, struct map *map)
2167 {
2168 struct build_id bid;
2169 char sbuild_id[SBUILD_ID_SIZE];
2170 bool is_host = false;
2171 char path[PATH_MAX];
2172
2173 if (!dso->has_build_id) {
2174 /*
2175 * Last resort, if we don't have a build-id and couldn't find
2176 * any vmlinux file, try the running kernel kallsyms table.
2177 */
2178 goto proc_kallsyms;
2179 }
2180
2181 if (sysfs__read_build_id("/sys/kernel/notes", &bid) == 0)
2182 is_host = dso__build_id_equal(dso, &bid);
2183
2184 /* Try a fast path for /proc/kallsyms if possible */
2185 if (is_host) {
2186 /*
2187 * Do not check the build-id cache, unless we know we cannot use
2188 * /proc/kcore or module maps don't match to /proc/kallsyms.
2189 * To check readability of /proc/kcore, do not use access(R_OK)
2190 * since /proc/kcore requires CAP_SYS_RAWIO to read and access
2191 * can't check it.
2192 */
2193 if (filename__readable("/proc/kcore") &&
2194 !validate_kcore_addresses("/proc/kallsyms", map))
2195 goto proc_kallsyms;
2196 }
2197
2198 build_id__sprintf(&dso->bid, sbuild_id);
2199
2200 /* Find kallsyms in build-id cache with kcore */
2201 scnprintf(path, sizeof(path), "%s/%s/%s",
2202 buildid_dir, DSO__NAME_KCORE, sbuild_id);
2203
2204 if (!find_matching_kcore(map, path, sizeof(path)))
2205 return strdup(path);
2206
2207 /* Use current /proc/kallsyms if possible */
2208 if (is_host) {
2209 proc_kallsyms:
2210 return strdup("/proc/kallsyms");
2211 }
2212
2213 /* Finally, find a cache of kallsyms */
2214 if (!build_id_cache__kallsyms_path(sbuild_id, path, sizeof(path))) {
2215 pr_err("No kallsyms or vmlinux with build-id %s was found\n",
2216 sbuild_id);
2217 return NULL;
2218 }
2219
2220 return strdup(path);
2221 }
2222
dso__load_kernel_sym(struct dso * dso,struct map * map)2223 static int dso__load_kernel_sym(struct dso *dso, struct map *map)
2224 {
2225 int err;
2226 const char *kallsyms_filename = NULL;
2227 char *kallsyms_allocated_filename = NULL;
2228 char *filename = NULL;
2229
2230 /*
2231 * Step 1: if the user specified a kallsyms or vmlinux filename, use
2232 * it and only it, reporting errors to the user if it cannot be used.
2233 *
2234 * For instance, try to analyse an ARM perf.data file _without_ a
2235 * build-id, or if the user specifies the wrong path to the right
2236 * vmlinux file, obviously we can't fallback to another vmlinux (a
2237 * x86_86 one, on the machine where analysis is being performed, say),
2238 * or worse, /proc/kallsyms.
2239 *
2240 * If the specified file _has_ a build-id and there is a build-id
2241 * section in the perf.data file, we will still do the expected
2242 * validation in dso__load_vmlinux and will bail out if they don't
2243 * match.
2244 */
2245 if (symbol_conf.kallsyms_name != NULL) {
2246 kallsyms_filename = symbol_conf.kallsyms_name;
2247 goto do_kallsyms;
2248 }
2249
2250 if (!symbol_conf.ignore_vmlinux && symbol_conf.vmlinux_name != NULL) {
2251 return dso__load_vmlinux(dso, map, symbol_conf.vmlinux_name, false);
2252 }
2253
2254 /*
2255 * Before checking on common vmlinux locations, check if it's
2256 * stored as standard build id binary (not kallsyms) under
2257 * .debug cache.
2258 */
2259 if (!symbol_conf.ignore_vmlinux_buildid)
2260 filename = __dso__build_id_filename(dso, NULL, 0, false, false);
2261 if (filename != NULL) {
2262 err = dso__load_vmlinux(dso, map, filename, true);
2263 if (err > 0)
2264 return err;
2265 free(filename);
2266 }
2267
2268 if (!symbol_conf.ignore_vmlinux && vmlinux_path != NULL) {
2269 err = dso__load_vmlinux_path(dso, map);
2270 if (err > 0)
2271 return err;
2272 }
2273
2274 /* do not try local files if a symfs was given */
2275 if (symbol_conf.symfs[0] != 0)
2276 return -1;
2277
2278 kallsyms_allocated_filename = dso__find_kallsyms(dso, map);
2279 if (!kallsyms_allocated_filename)
2280 return -1;
2281
2282 kallsyms_filename = kallsyms_allocated_filename;
2283
2284 do_kallsyms:
2285 err = dso__load_kallsyms(dso, kallsyms_filename, map);
2286 if (err > 0)
2287 pr_debug("Using %s for symbols\n", kallsyms_filename);
2288 free(kallsyms_allocated_filename);
2289
2290 if (err > 0 && !dso__is_kcore(dso)) {
2291 dso->binary_type = DSO_BINARY_TYPE__KALLSYMS;
2292 dso__set_long_name(dso, DSO__NAME_KALLSYMS, false);
2293 map__fixup_start(map);
2294 map__fixup_end(map);
2295 }
2296
2297 return err;
2298 }
2299
dso__load_guest_kernel_sym(struct dso * dso,struct map * map)2300 static int dso__load_guest_kernel_sym(struct dso *dso, struct map *map)
2301 {
2302 int err;
2303 const char *kallsyms_filename;
2304 struct machine *machine = map__kmaps(map)->machine;
2305 char path[PATH_MAX];
2306
2307 if (machine->kallsyms_filename) {
2308 kallsyms_filename = machine->kallsyms_filename;
2309 } else if (machine__is_default_guest(machine)) {
2310 /*
2311 * if the user specified a vmlinux filename, use it and only
2312 * it, reporting errors to the user if it cannot be used.
2313 * Or use file guest_kallsyms inputted by user on commandline
2314 */
2315 if (symbol_conf.default_guest_vmlinux_name != NULL) {
2316 err = dso__load_vmlinux(dso, map,
2317 symbol_conf.default_guest_vmlinux_name,
2318 false);
2319 return err;
2320 }
2321
2322 kallsyms_filename = symbol_conf.default_guest_kallsyms;
2323 if (!kallsyms_filename)
2324 return -1;
2325 } else {
2326 sprintf(path, "%s/proc/kallsyms", machine->root_dir);
2327 kallsyms_filename = path;
2328 }
2329
2330 err = dso__load_kallsyms(dso, kallsyms_filename, map);
2331 if (err > 0)
2332 pr_debug("Using %s for symbols\n", kallsyms_filename);
2333 if (err > 0 && !dso__is_kcore(dso)) {
2334 dso->binary_type = DSO_BINARY_TYPE__GUEST_KALLSYMS;
2335 dso__set_long_name(dso, machine->mmap_name, false);
2336 map__fixup_start(map);
2337 map__fixup_end(map);
2338 }
2339
2340 return err;
2341 }
2342
vmlinux_path__exit(void)2343 static void vmlinux_path__exit(void)
2344 {
2345 while (--vmlinux_path__nr_entries >= 0)
2346 zfree(&vmlinux_path[vmlinux_path__nr_entries]);
2347 vmlinux_path__nr_entries = 0;
2348
2349 zfree(&vmlinux_path);
2350 }
2351
2352 static const char * const vmlinux_paths[] = {
2353 "vmlinux",
2354 "/boot/vmlinux"
2355 };
2356
2357 static const char * const vmlinux_paths_upd[] = {
2358 "/boot/vmlinux-%s",
2359 "/usr/lib/debug/boot/vmlinux-%s",
2360 "/lib/modules/%s/build/vmlinux",
2361 "/usr/lib/debug/lib/modules/%s/vmlinux",
2362 "/usr/lib/debug/boot/vmlinux-%s.debug"
2363 };
2364
vmlinux_path__add(const char * new_entry)2365 static int vmlinux_path__add(const char *new_entry)
2366 {
2367 vmlinux_path[vmlinux_path__nr_entries] = strdup(new_entry);
2368 if (vmlinux_path[vmlinux_path__nr_entries] == NULL)
2369 return -1;
2370 ++vmlinux_path__nr_entries;
2371
2372 return 0;
2373 }
2374
vmlinux_path__init(struct perf_env * env)2375 static int vmlinux_path__init(struct perf_env *env)
2376 {
2377 struct utsname uts;
2378 char bf[PATH_MAX];
2379 char *kernel_version;
2380 unsigned int i;
2381
2382 vmlinux_path = malloc(sizeof(char *) * (ARRAY_SIZE(vmlinux_paths) +
2383 ARRAY_SIZE(vmlinux_paths_upd)));
2384 if (vmlinux_path == NULL)
2385 return -1;
2386
2387 for (i = 0; i < ARRAY_SIZE(vmlinux_paths); i++)
2388 if (vmlinux_path__add(vmlinux_paths[i]) < 0)
2389 goto out_fail;
2390
2391 /* only try kernel version if no symfs was given */
2392 if (symbol_conf.symfs[0] != 0)
2393 return 0;
2394
2395 if (env) {
2396 kernel_version = env->os_release;
2397 } else {
2398 if (uname(&uts) < 0)
2399 goto out_fail;
2400
2401 kernel_version = uts.release;
2402 }
2403
2404 for (i = 0; i < ARRAY_SIZE(vmlinux_paths_upd); i++) {
2405 snprintf(bf, sizeof(bf), vmlinux_paths_upd[i], kernel_version);
2406 if (vmlinux_path__add(bf) < 0)
2407 goto out_fail;
2408 }
2409
2410 return 0;
2411
2412 out_fail:
2413 vmlinux_path__exit();
2414 return -1;
2415 }
2416
setup_list(struct strlist ** list,const char * list_str,const char * list_name)2417 int setup_list(struct strlist **list, const char *list_str,
2418 const char *list_name)
2419 {
2420 if (list_str == NULL)
2421 return 0;
2422
2423 *list = strlist__new(list_str, NULL);
2424 if (!*list) {
2425 pr_err("problems parsing %s list\n", list_name);
2426 return -1;
2427 }
2428
2429 symbol_conf.has_filter = true;
2430 return 0;
2431 }
2432
setup_intlist(struct intlist ** list,const char * list_str,const char * list_name)2433 int setup_intlist(struct intlist **list, const char *list_str,
2434 const char *list_name)
2435 {
2436 if (list_str == NULL)
2437 return 0;
2438
2439 *list = intlist__new(list_str);
2440 if (!*list) {
2441 pr_err("problems parsing %s list\n", list_name);
2442 return -1;
2443 }
2444 return 0;
2445 }
2446
setup_addrlist(struct intlist ** addr_list,struct strlist * sym_list)2447 static int setup_addrlist(struct intlist **addr_list, struct strlist *sym_list)
2448 {
2449 struct str_node *pos, *tmp;
2450 unsigned long val;
2451 char *sep;
2452 const char *end;
2453 int i = 0, err;
2454
2455 *addr_list = intlist__new(NULL);
2456 if (!*addr_list)
2457 return -1;
2458
2459 strlist__for_each_entry_safe(pos, tmp, sym_list) {
2460 errno = 0;
2461 val = strtoul(pos->s, &sep, 16);
2462 if (errno || (sep == pos->s))
2463 continue;
2464
2465 if (*sep != '\0') {
2466 end = pos->s + strlen(pos->s) - 1;
2467 while (end >= sep && isspace(*end))
2468 end--;
2469
2470 if (end >= sep)
2471 continue;
2472 }
2473
2474 err = intlist__add(*addr_list, val);
2475 if (err)
2476 break;
2477
2478 strlist__remove(sym_list, pos);
2479 i++;
2480 }
2481
2482 if (i == 0) {
2483 intlist__delete(*addr_list);
2484 *addr_list = NULL;
2485 }
2486
2487 return 0;
2488 }
2489
symbol__read_kptr_restrict(void)2490 static bool symbol__read_kptr_restrict(void)
2491 {
2492 bool value = false;
2493 FILE *fp = fopen("/proc/sys/kernel/kptr_restrict", "r");
2494
2495 if (fp != NULL) {
2496 char line[8];
2497
2498 if (fgets(line, sizeof(line), fp) != NULL)
2499 value = perf_cap__capable(CAP_SYSLOG) ?
2500 (atoi(line) >= 2) :
2501 (atoi(line) != 0);
2502
2503 fclose(fp);
2504 }
2505
2506 /* Per kernel/kallsyms.c:
2507 * we also restrict when perf_event_paranoid > 1 w/o CAP_SYSLOG
2508 */
2509 if (perf_event_paranoid() > 1 && !perf_cap__capable(CAP_SYSLOG))
2510 value = true;
2511
2512 return value;
2513 }
2514
symbol__annotation_init(void)2515 int symbol__annotation_init(void)
2516 {
2517 if (symbol_conf.init_annotation)
2518 return 0;
2519
2520 if (symbol_conf.initialized) {
2521 pr_err("Annotation needs to be init before symbol__init()\n");
2522 return -1;
2523 }
2524
2525 symbol_conf.priv_size += sizeof(struct annotation);
2526 symbol_conf.init_annotation = true;
2527 return 0;
2528 }
2529
symbol__init(struct perf_env * env)2530 int symbol__init(struct perf_env *env)
2531 {
2532 const char *symfs;
2533
2534 if (symbol_conf.initialized)
2535 return 0;
2536
2537 symbol_conf.priv_size = PERF_ALIGN(symbol_conf.priv_size, sizeof(u64));
2538
2539 symbol__elf_init();
2540
2541 if (symbol_conf.sort_by_name)
2542 symbol_conf.priv_size += (sizeof(struct symbol_name_rb_node) -
2543 sizeof(struct symbol));
2544
2545 if (symbol_conf.try_vmlinux_path && vmlinux_path__init(env) < 0)
2546 return -1;
2547
2548 if (symbol_conf.field_sep && *symbol_conf.field_sep == '.') {
2549 pr_err("'.' is the only non valid --field-separator argument\n");
2550 return -1;
2551 }
2552
2553 if (setup_list(&symbol_conf.dso_list,
2554 symbol_conf.dso_list_str, "dso") < 0)
2555 return -1;
2556
2557 if (setup_list(&symbol_conf.comm_list,
2558 symbol_conf.comm_list_str, "comm") < 0)
2559 goto out_free_dso_list;
2560
2561 if (setup_intlist(&symbol_conf.pid_list,
2562 symbol_conf.pid_list_str, "pid") < 0)
2563 goto out_free_comm_list;
2564
2565 if (setup_intlist(&symbol_conf.tid_list,
2566 symbol_conf.tid_list_str, "tid") < 0)
2567 goto out_free_pid_list;
2568
2569 if (setup_list(&symbol_conf.sym_list,
2570 symbol_conf.sym_list_str, "symbol") < 0)
2571 goto out_free_tid_list;
2572
2573 if (symbol_conf.sym_list &&
2574 setup_addrlist(&symbol_conf.addr_list, symbol_conf.sym_list) < 0)
2575 goto out_free_sym_list;
2576
2577 if (setup_list(&symbol_conf.bt_stop_list,
2578 symbol_conf.bt_stop_list_str, "symbol") < 0)
2579 goto out_free_sym_list;
2580
2581 /*
2582 * A path to symbols of "/" is identical to ""
2583 * reset here for simplicity.
2584 */
2585 symfs = realpath(symbol_conf.symfs, NULL);
2586 if (symfs == NULL)
2587 symfs = symbol_conf.symfs;
2588 if (strcmp(symfs, "/") == 0)
2589 symbol_conf.symfs = "";
2590 if (symfs != symbol_conf.symfs)
2591 free((void *)symfs);
2592
2593 symbol_conf.kptr_restrict = symbol__read_kptr_restrict();
2594
2595 symbol_conf.initialized = true;
2596 return 0;
2597
2598 out_free_sym_list:
2599 strlist__delete(symbol_conf.sym_list);
2600 intlist__delete(symbol_conf.addr_list);
2601 out_free_tid_list:
2602 intlist__delete(symbol_conf.tid_list);
2603 out_free_pid_list:
2604 intlist__delete(symbol_conf.pid_list);
2605 out_free_comm_list:
2606 strlist__delete(symbol_conf.comm_list);
2607 out_free_dso_list:
2608 strlist__delete(symbol_conf.dso_list);
2609 return -1;
2610 }
2611
symbol__exit(void)2612 void symbol__exit(void)
2613 {
2614 if (!symbol_conf.initialized)
2615 return;
2616 strlist__delete(symbol_conf.bt_stop_list);
2617 strlist__delete(symbol_conf.sym_list);
2618 strlist__delete(symbol_conf.dso_list);
2619 strlist__delete(symbol_conf.comm_list);
2620 intlist__delete(symbol_conf.tid_list);
2621 intlist__delete(symbol_conf.pid_list);
2622 intlist__delete(symbol_conf.addr_list);
2623 vmlinux_path__exit();
2624 symbol_conf.sym_list = symbol_conf.dso_list = symbol_conf.comm_list = NULL;
2625 symbol_conf.bt_stop_list = NULL;
2626 symbol_conf.initialized = false;
2627 }
2628
symbol__config_symfs(const struct option * opt __maybe_unused,const char * dir,int unset __maybe_unused)2629 int symbol__config_symfs(const struct option *opt __maybe_unused,
2630 const char *dir, int unset __maybe_unused)
2631 {
2632 char *bf = NULL;
2633 int ret;
2634
2635 symbol_conf.symfs = strdup(dir);
2636 if (symbol_conf.symfs == NULL)
2637 return -ENOMEM;
2638
2639 /* skip the locally configured cache if a symfs is given, and
2640 * config buildid dir to symfs/.debug
2641 */
2642 ret = asprintf(&bf, "%s/%s", dir, ".debug");
2643 if (ret < 0)
2644 return -ENOMEM;
2645
2646 set_buildid_dir(bf);
2647
2648 free(bf);
2649 return 0;
2650 }
2651
mem_info__get(struct mem_info * mi)2652 struct mem_info *mem_info__get(struct mem_info *mi)
2653 {
2654 if (mi)
2655 refcount_inc(&mi->refcnt);
2656 return mi;
2657 }
2658
mem_info__put(struct mem_info * mi)2659 void mem_info__put(struct mem_info *mi)
2660 {
2661 if (mi && refcount_dec_and_test(&mi->refcnt))
2662 free(mi);
2663 }
2664
mem_info__new(void)2665 struct mem_info *mem_info__new(void)
2666 {
2667 struct mem_info *mi = zalloc(sizeof(*mi));
2668
2669 if (mi)
2670 refcount_set(&mi->refcnt, 1);
2671 return mi;
2672 }
2673
2674 /*
2675 * Checks that user supplied symbol kernel files are accessible because
2676 * the default mechanism for accessing elf files fails silently. i.e. if
2677 * debug syms for a build ID aren't found perf carries on normally. When
2678 * they are user supplied we should assume that the user doesn't want to
2679 * silently fail.
2680 */
symbol__validate_sym_arguments(void)2681 int symbol__validate_sym_arguments(void)
2682 {
2683 if (symbol_conf.vmlinux_name &&
2684 access(symbol_conf.vmlinux_name, R_OK)) {
2685 pr_err("Invalid file: %s\n", symbol_conf.vmlinux_name);
2686 return -EINVAL;
2687 }
2688 if (symbol_conf.kallsyms_name &&
2689 access(symbol_conf.kallsyms_name, R_OK)) {
2690 pr_err("Invalid file: %s\n", symbol_conf.kallsyms_name);
2691 return -EINVAL;
2692 }
2693 return 0;
2694 }
2695