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 pthread_mutex_init(¬es->lock, NULL);
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 free(((void *)sym) - symbol_conf.priv_size);
315 }
316
symbols__delete(struct rb_root_cached * symbols)317 void symbols__delete(struct rb_root_cached *symbols)
318 {
319 struct symbol *pos;
320 struct rb_node *next = rb_first_cached(symbols);
321
322 while (next) {
323 pos = rb_entry(next, struct symbol, rb_node);
324 next = rb_next(&pos->rb_node);
325 rb_erase_cached(&pos->rb_node, symbols);
326 symbol__delete(pos);
327 }
328 }
329
__symbols__insert(struct rb_root_cached * symbols,struct symbol * sym,bool kernel)330 void __symbols__insert(struct rb_root_cached *symbols,
331 struct symbol *sym, bool kernel)
332 {
333 struct rb_node **p = &symbols->rb_root.rb_node;
334 struct rb_node *parent = NULL;
335 const u64 ip = sym->start;
336 struct symbol *s;
337 bool leftmost = true;
338
339 if (kernel) {
340 const char *name = sym->name;
341 /*
342 * ppc64 uses function descriptors and appends a '.' to the
343 * start of every instruction address. Remove it.
344 */
345 if (name[0] == '.')
346 name++;
347 sym->idle = symbol__is_idle(name);
348 }
349
350 while (*p != NULL) {
351 parent = *p;
352 s = rb_entry(parent, struct symbol, rb_node);
353 if (ip < s->start)
354 p = &(*p)->rb_left;
355 else {
356 p = &(*p)->rb_right;
357 leftmost = false;
358 }
359 }
360 rb_link_node(&sym->rb_node, parent, p);
361 rb_insert_color_cached(&sym->rb_node, symbols, leftmost);
362 }
363
symbols__insert(struct rb_root_cached * symbols,struct symbol * sym)364 void symbols__insert(struct rb_root_cached *symbols, struct symbol *sym)
365 {
366 __symbols__insert(symbols, sym, false);
367 }
368
symbols__find(struct rb_root_cached * symbols,u64 ip)369 static struct symbol *symbols__find(struct rb_root_cached *symbols, u64 ip)
370 {
371 struct rb_node *n;
372
373 if (symbols == NULL)
374 return NULL;
375
376 n = symbols->rb_root.rb_node;
377
378 while (n) {
379 struct symbol *s = rb_entry(n, struct symbol, rb_node);
380
381 if (ip < s->start)
382 n = n->rb_left;
383 else if (ip > s->end || (ip == s->end && ip != s->start))
384 n = n->rb_right;
385 else
386 return s;
387 }
388
389 return NULL;
390 }
391
symbols__first(struct rb_root_cached * symbols)392 static struct symbol *symbols__first(struct rb_root_cached *symbols)
393 {
394 struct rb_node *n = rb_first_cached(symbols);
395
396 if (n)
397 return rb_entry(n, struct symbol, rb_node);
398
399 return NULL;
400 }
401
symbols__last(struct rb_root_cached * symbols)402 static struct symbol *symbols__last(struct rb_root_cached *symbols)
403 {
404 struct rb_node *n = rb_last(&symbols->rb_root);
405
406 if (n)
407 return rb_entry(n, struct symbol, rb_node);
408
409 return NULL;
410 }
411
symbols__next(struct symbol * sym)412 static struct symbol *symbols__next(struct symbol *sym)
413 {
414 struct rb_node *n = rb_next(&sym->rb_node);
415
416 if (n)
417 return rb_entry(n, struct symbol, rb_node);
418
419 return NULL;
420 }
421
symbols__insert_by_name(struct rb_root_cached * symbols,struct symbol * sym)422 static void symbols__insert_by_name(struct rb_root_cached *symbols, struct symbol *sym)
423 {
424 struct rb_node **p = &symbols->rb_root.rb_node;
425 struct rb_node *parent = NULL;
426 struct symbol_name_rb_node *symn, *s;
427 bool leftmost = true;
428
429 symn = container_of(sym, struct symbol_name_rb_node, sym);
430
431 while (*p != NULL) {
432 parent = *p;
433 s = rb_entry(parent, struct symbol_name_rb_node, rb_node);
434 if (strcmp(sym->name, s->sym.name) < 0)
435 p = &(*p)->rb_left;
436 else {
437 p = &(*p)->rb_right;
438 leftmost = false;
439 }
440 }
441 rb_link_node(&symn->rb_node, parent, p);
442 rb_insert_color_cached(&symn->rb_node, symbols, leftmost);
443 }
444
symbols__sort_by_name(struct rb_root_cached * symbols,struct rb_root_cached * source)445 static void symbols__sort_by_name(struct rb_root_cached *symbols,
446 struct rb_root_cached *source)
447 {
448 struct rb_node *nd;
449
450 for (nd = rb_first_cached(source); nd; nd = rb_next(nd)) {
451 struct symbol *pos = rb_entry(nd, struct symbol, rb_node);
452 symbols__insert_by_name(symbols, pos);
453 }
454 }
455
symbol__match_symbol_name(const char * name,const char * str,enum symbol_tag_include includes)456 int symbol__match_symbol_name(const char *name, const char *str,
457 enum symbol_tag_include includes)
458 {
459 const char *versioning;
460
461 if (includes == SYMBOL_TAG_INCLUDE__DEFAULT_ONLY &&
462 (versioning = strstr(name, "@@"))) {
463 int len = strlen(str);
464
465 if (len < versioning - name)
466 len = versioning - name;
467
468 return arch__compare_symbol_names_n(name, str, len);
469 } else
470 return arch__compare_symbol_names(name, str);
471 }
472
symbols__find_by_name(struct rb_root_cached * symbols,const char * name,enum symbol_tag_include includes)473 static struct symbol *symbols__find_by_name(struct rb_root_cached *symbols,
474 const char *name,
475 enum symbol_tag_include includes)
476 {
477 struct rb_node *n;
478 struct symbol_name_rb_node *s = NULL;
479
480 if (symbols == NULL)
481 return NULL;
482
483 n = symbols->rb_root.rb_node;
484
485 while (n) {
486 int cmp;
487
488 s = rb_entry(n, struct symbol_name_rb_node, rb_node);
489 cmp = symbol__match_symbol_name(s->sym.name, name, includes);
490
491 if (cmp > 0)
492 n = n->rb_left;
493 else if (cmp < 0)
494 n = n->rb_right;
495 else
496 break;
497 }
498
499 if (n == NULL)
500 return NULL;
501
502 if (includes != SYMBOL_TAG_INCLUDE__DEFAULT_ONLY)
503 /* return first symbol that has same name (if any) */
504 for (n = rb_prev(n); n; n = rb_prev(n)) {
505 struct symbol_name_rb_node *tmp;
506
507 tmp = rb_entry(n, struct symbol_name_rb_node, rb_node);
508 if (arch__compare_symbol_names(tmp->sym.name, s->sym.name))
509 break;
510
511 s = tmp;
512 }
513
514 return &s->sym;
515 }
516
dso__reset_find_symbol_cache(struct dso * dso)517 void dso__reset_find_symbol_cache(struct dso *dso)
518 {
519 dso->last_find_result.addr = 0;
520 dso->last_find_result.symbol = NULL;
521 }
522
dso__insert_symbol(struct dso * dso,struct symbol * sym)523 void dso__insert_symbol(struct dso *dso, struct symbol *sym)
524 {
525 __symbols__insert(&dso->symbols, sym, dso->kernel);
526
527 /* update the symbol cache if necessary */
528 if (dso->last_find_result.addr >= sym->start &&
529 (dso->last_find_result.addr < sym->end ||
530 sym->start == sym->end)) {
531 dso->last_find_result.symbol = sym;
532 }
533 }
534
dso__delete_symbol(struct dso * dso,struct symbol * sym)535 void dso__delete_symbol(struct dso *dso, struct symbol *sym)
536 {
537 rb_erase_cached(&sym->rb_node, &dso->symbols);
538 symbol__delete(sym);
539 dso__reset_find_symbol_cache(dso);
540 }
541
dso__find_symbol(struct dso * dso,u64 addr)542 struct symbol *dso__find_symbol(struct dso *dso, u64 addr)
543 {
544 if (dso->last_find_result.addr != addr || dso->last_find_result.symbol == NULL) {
545 dso->last_find_result.addr = addr;
546 dso->last_find_result.symbol = symbols__find(&dso->symbols, addr);
547 }
548
549 return dso->last_find_result.symbol;
550 }
551
dso__first_symbol(struct dso * dso)552 struct symbol *dso__first_symbol(struct dso *dso)
553 {
554 return symbols__first(&dso->symbols);
555 }
556
dso__last_symbol(struct dso * dso)557 struct symbol *dso__last_symbol(struct dso *dso)
558 {
559 return symbols__last(&dso->symbols);
560 }
561
dso__next_symbol(struct symbol * sym)562 struct symbol *dso__next_symbol(struct symbol *sym)
563 {
564 return symbols__next(sym);
565 }
566
symbol__next_by_name(struct symbol * sym)567 struct symbol *symbol__next_by_name(struct symbol *sym)
568 {
569 struct symbol_name_rb_node *s = container_of(sym, struct symbol_name_rb_node, sym);
570 struct rb_node *n = rb_next(&s->rb_node);
571
572 return n ? &rb_entry(n, struct symbol_name_rb_node, rb_node)->sym : NULL;
573 }
574
575 /*
576 * Returns first symbol that matched with @name.
577 */
dso__find_symbol_by_name(struct dso * dso,const char * name)578 struct symbol *dso__find_symbol_by_name(struct dso *dso, const char *name)
579 {
580 struct symbol *s = symbols__find_by_name(&dso->symbol_names, name,
581 SYMBOL_TAG_INCLUDE__NONE);
582 if (!s)
583 s = symbols__find_by_name(&dso->symbol_names, name,
584 SYMBOL_TAG_INCLUDE__DEFAULT_ONLY);
585 return s;
586 }
587
dso__sort_by_name(struct dso * dso)588 void dso__sort_by_name(struct dso *dso)
589 {
590 dso__set_sorted_by_name(dso);
591 return symbols__sort_by_name(&dso->symbol_names, &dso->symbols);
592 }
593
594 /*
595 * While we find nice hex chars, build a long_val.
596 * Return number of chars processed.
597 */
hex2u64(const char * ptr,u64 * long_val)598 static int hex2u64(const char *ptr, u64 *long_val)
599 {
600 char *p;
601
602 *long_val = strtoull(ptr, &p, 16);
603
604 return p - ptr;
605 }
606
607
modules__parse(const char * filename,void * arg,int (* process_module)(void * arg,const char * name,u64 start,u64 size))608 int modules__parse(const char *filename, void *arg,
609 int (*process_module)(void *arg, const char *name,
610 u64 start, u64 size))
611 {
612 char *line = NULL;
613 size_t n;
614 FILE *file;
615 int err = 0;
616
617 file = fopen(filename, "r");
618 if (file == NULL)
619 return -1;
620
621 while (1) {
622 char name[PATH_MAX];
623 u64 start, size;
624 char *sep, *endptr;
625 ssize_t line_len;
626
627 line_len = getline(&line, &n, file);
628 if (line_len < 0) {
629 if (feof(file))
630 break;
631 err = -1;
632 goto out;
633 }
634
635 if (!line) {
636 err = -1;
637 goto out;
638 }
639
640 line[--line_len] = '\0'; /* \n */
641
642 sep = strrchr(line, 'x');
643 if (sep == NULL)
644 continue;
645
646 hex2u64(sep + 1, &start);
647
648 sep = strchr(line, ' ');
649 if (sep == NULL)
650 continue;
651
652 *sep = '\0';
653
654 scnprintf(name, sizeof(name), "[%s]", line);
655
656 size = strtoul(sep + 1, &endptr, 0);
657 if (*endptr != ' ' && *endptr != '\t')
658 continue;
659
660 err = process_module(arg, name, start, size);
661 if (err)
662 break;
663 }
664 out:
665 free(line);
666 fclose(file);
667 return err;
668 }
669
670 /*
671 * These are symbols in the kernel image, so make sure that
672 * sym is from a kernel DSO.
673 */
symbol__is_idle(const char * name)674 static bool symbol__is_idle(const char *name)
675 {
676 const char * const idle_symbols[] = {
677 "acpi_idle_do_entry",
678 "acpi_processor_ffh_cstate_enter",
679 "arch_cpu_idle",
680 "cpu_idle",
681 "cpu_startup_entry",
682 "idle_cpu",
683 "intel_idle",
684 "default_idle",
685 "native_safe_halt",
686 "enter_idle",
687 "exit_idle",
688 "mwait_idle",
689 "mwait_idle_with_hints",
690 "mwait_idle_with_hints.constprop.0",
691 "poll_idle",
692 "ppc64_runlatch_off",
693 "pseries_dedicated_idle_sleep",
694 "psw_idle",
695 "psw_idle_exit",
696 NULL
697 };
698 int i;
699 static struct strlist *idle_symbols_list;
700
701 if (idle_symbols_list)
702 return strlist__has_entry(idle_symbols_list, name);
703
704 idle_symbols_list = strlist__new(NULL, NULL);
705
706 for (i = 0; idle_symbols[i]; i++)
707 strlist__add(idle_symbols_list, idle_symbols[i]);
708
709 return strlist__has_entry(idle_symbols_list, name);
710 }
711
map__process_kallsym_symbol(void * arg,const char * name,char type,u64 start)712 static int map__process_kallsym_symbol(void *arg, const char *name,
713 char type, u64 start)
714 {
715 struct symbol *sym;
716 struct dso *dso = arg;
717 struct rb_root_cached *root = &dso->symbols;
718
719 if (!symbol_type__filter(type))
720 return 0;
721
722 /*
723 * module symbols are not sorted so we add all
724 * symbols, setting length to 0, and rely on
725 * symbols__fixup_end() to fix it up.
726 */
727 sym = symbol__new(start, 0, kallsyms2elf_binding(type), kallsyms2elf_type(type), name);
728 if (sym == NULL)
729 return -ENOMEM;
730 /*
731 * We will pass the symbols to the filter later, in
732 * map__split_kallsyms, when we have split the maps per module
733 */
734 __symbols__insert(root, sym, !strchr(name, '['));
735
736 return 0;
737 }
738
739 /*
740 * Loads the function entries in /proc/kallsyms into kernel_map->dso,
741 * so that we can in the next step set the symbol ->end address and then
742 * call kernel_maps__split_kallsyms.
743 */
dso__load_all_kallsyms(struct dso * dso,const char * filename)744 static int dso__load_all_kallsyms(struct dso *dso, const char *filename)
745 {
746 return kallsyms__parse(filename, dso, map__process_kallsym_symbol);
747 }
748
maps__split_kallsyms_for_kcore(struct maps * kmaps,struct dso * dso)749 static int maps__split_kallsyms_for_kcore(struct maps *kmaps, struct dso *dso)
750 {
751 struct map *curr_map;
752 struct symbol *pos;
753 int count = 0;
754 struct rb_root_cached old_root = dso->symbols;
755 struct rb_root_cached *root = &dso->symbols;
756 struct rb_node *next = rb_first_cached(root);
757
758 if (!kmaps)
759 return -1;
760
761 *root = RB_ROOT_CACHED;
762
763 while (next) {
764 char *module;
765
766 pos = rb_entry(next, struct symbol, rb_node);
767 next = rb_next(&pos->rb_node);
768
769 rb_erase_cached(&pos->rb_node, &old_root);
770 RB_CLEAR_NODE(&pos->rb_node);
771 module = strchr(pos->name, '\t');
772 if (module)
773 *module = '\0';
774
775 curr_map = maps__find(kmaps, pos->start);
776
777 if (!curr_map) {
778 symbol__delete(pos);
779 continue;
780 }
781
782 pos->start -= curr_map->start - curr_map->pgoff;
783 if (pos->end > curr_map->end)
784 pos->end = curr_map->end;
785 if (pos->end)
786 pos->end -= curr_map->start - curr_map->pgoff;
787 symbols__insert(&curr_map->dso->symbols, pos);
788 ++count;
789 }
790
791 /* Symbols have been adjusted */
792 dso->adjust_symbols = 1;
793
794 return count;
795 }
796
797 /*
798 * Split the symbols into maps, making sure there are no overlaps, i.e. the
799 * kernel range is broken in several maps, named [kernel].N, as we don't have
800 * the original ELF section names vmlinux have.
801 */
maps__split_kallsyms(struct maps * kmaps,struct dso * dso,u64 delta,struct map * initial_map)802 static int maps__split_kallsyms(struct maps *kmaps, struct dso *dso, u64 delta,
803 struct map *initial_map)
804 {
805 struct machine *machine;
806 struct map *curr_map = initial_map;
807 struct symbol *pos;
808 int count = 0, moved = 0;
809 struct rb_root_cached *root = &dso->symbols;
810 struct rb_node *next = rb_first_cached(root);
811 int kernel_range = 0;
812 bool x86_64;
813
814 if (!kmaps)
815 return -1;
816
817 machine = kmaps->machine;
818
819 x86_64 = machine__is(machine, "x86_64");
820
821 while (next) {
822 char *module;
823
824 pos = rb_entry(next, struct symbol, rb_node);
825 next = rb_next(&pos->rb_node);
826
827 module = strchr(pos->name, '\t');
828 if (module) {
829 if (!symbol_conf.use_modules)
830 goto discard_symbol;
831
832 *module++ = '\0';
833
834 if (strcmp(curr_map->dso->short_name, module)) {
835 if (curr_map != initial_map &&
836 dso->kernel == DSO_SPACE__KERNEL_GUEST &&
837 machine__is_default_guest(machine)) {
838 /*
839 * We assume all symbols of a module are
840 * continuous in * kallsyms, so curr_map
841 * points to a module and all its
842 * symbols are in its kmap. Mark it as
843 * loaded.
844 */
845 dso__set_loaded(curr_map->dso);
846 }
847
848 curr_map = maps__find_by_name(kmaps, module);
849 if (curr_map == NULL) {
850 pr_debug("%s/proc/{kallsyms,modules} "
851 "inconsistency while looking "
852 "for \"%s\" module!\n",
853 machine->root_dir, module);
854 curr_map = initial_map;
855 goto discard_symbol;
856 }
857
858 if (curr_map->dso->loaded &&
859 !machine__is_default_guest(machine))
860 goto discard_symbol;
861 }
862 /*
863 * So that we look just like we get from .ko files,
864 * i.e. not prelinked, relative to initial_map->start.
865 */
866 pos->start = curr_map->map_ip(curr_map, pos->start);
867 pos->end = curr_map->map_ip(curr_map, pos->end);
868 } else if (x86_64 && is_entry_trampoline(pos->name)) {
869 /*
870 * These symbols are not needed anymore since the
871 * trampoline maps refer to the text section and it's
872 * symbols instead. Avoid having to deal with
873 * relocations, and the assumption that the first symbol
874 * is the start of kernel text, by simply removing the
875 * symbols at this point.
876 */
877 goto discard_symbol;
878 } else if (curr_map != initial_map) {
879 char dso_name[PATH_MAX];
880 struct dso *ndso;
881
882 if (delta) {
883 /* Kernel was relocated at boot time */
884 pos->start -= delta;
885 pos->end -= delta;
886 }
887
888 if (count == 0) {
889 curr_map = initial_map;
890 goto add_symbol;
891 }
892
893 if (dso->kernel == DSO_SPACE__KERNEL_GUEST)
894 snprintf(dso_name, sizeof(dso_name),
895 "[guest.kernel].%d",
896 kernel_range++);
897 else
898 snprintf(dso_name, sizeof(dso_name),
899 "[kernel].%d",
900 kernel_range++);
901
902 ndso = dso__new(dso_name);
903 if (ndso == NULL)
904 return -1;
905
906 ndso->kernel = dso->kernel;
907
908 curr_map = map__new2(pos->start, ndso);
909 if (curr_map == NULL) {
910 dso__put(ndso);
911 return -1;
912 }
913
914 curr_map->map_ip = curr_map->unmap_ip = identity__map_ip;
915 maps__insert(kmaps, curr_map);
916 ++kernel_range;
917 } else if (delta) {
918 /* Kernel was relocated at boot time */
919 pos->start -= delta;
920 pos->end -= delta;
921 }
922 add_symbol:
923 if (curr_map != initial_map) {
924 rb_erase_cached(&pos->rb_node, root);
925 symbols__insert(&curr_map->dso->symbols, pos);
926 ++moved;
927 } else
928 ++count;
929
930 continue;
931 discard_symbol:
932 rb_erase_cached(&pos->rb_node, root);
933 symbol__delete(pos);
934 }
935
936 if (curr_map != initial_map &&
937 dso->kernel == DSO_SPACE__KERNEL_GUEST &&
938 machine__is_default_guest(kmaps->machine)) {
939 dso__set_loaded(curr_map->dso);
940 }
941
942 return count + moved;
943 }
944
symbol__restricted_filename(const char * filename,const char * restricted_filename)945 bool symbol__restricted_filename(const char *filename,
946 const char *restricted_filename)
947 {
948 bool restricted = false;
949
950 if (symbol_conf.kptr_restrict) {
951 char *r = realpath(filename, NULL);
952
953 if (r != NULL) {
954 restricted = strcmp(r, restricted_filename) == 0;
955 free(r);
956 return restricted;
957 }
958 }
959
960 return restricted;
961 }
962
963 struct module_info {
964 struct rb_node rb_node;
965 char *name;
966 u64 start;
967 };
968
add_module(struct module_info * mi,struct rb_root * modules)969 static void add_module(struct module_info *mi, struct rb_root *modules)
970 {
971 struct rb_node **p = &modules->rb_node;
972 struct rb_node *parent = NULL;
973 struct module_info *m;
974
975 while (*p != NULL) {
976 parent = *p;
977 m = rb_entry(parent, struct module_info, rb_node);
978 if (strcmp(mi->name, m->name) < 0)
979 p = &(*p)->rb_left;
980 else
981 p = &(*p)->rb_right;
982 }
983 rb_link_node(&mi->rb_node, parent, p);
984 rb_insert_color(&mi->rb_node, modules);
985 }
986
delete_modules(struct rb_root * modules)987 static void delete_modules(struct rb_root *modules)
988 {
989 struct module_info *mi;
990 struct rb_node *next = rb_first(modules);
991
992 while (next) {
993 mi = rb_entry(next, struct module_info, rb_node);
994 next = rb_next(&mi->rb_node);
995 rb_erase(&mi->rb_node, modules);
996 zfree(&mi->name);
997 free(mi);
998 }
999 }
1000
find_module(const char * name,struct rb_root * modules)1001 static struct module_info *find_module(const char *name,
1002 struct rb_root *modules)
1003 {
1004 struct rb_node *n = modules->rb_node;
1005
1006 while (n) {
1007 struct module_info *m;
1008 int cmp;
1009
1010 m = rb_entry(n, struct module_info, rb_node);
1011 cmp = strcmp(name, m->name);
1012 if (cmp < 0)
1013 n = n->rb_left;
1014 else if (cmp > 0)
1015 n = n->rb_right;
1016 else
1017 return m;
1018 }
1019
1020 return NULL;
1021 }
1022
__read_proc_modules(void * arg,const char * name,u64 start,u64 size __maybe_unused)1023 static int __read_proc_modules(void *arg, const char *name, u64 start,
1024 u64 size __maybe_unused)
1025 {
1026 struct rb_root *modules = arg;
1027 struct module_info *mi;
1028
1029 mi = zalloc(sizeof(struct module_info));
1030 if (!mi)
1031 return -ENOMEM;
1032
1033 mi->name = strdup(name);
1034 mi->start = start;
1035
1036 if (!mi->name) {
1037 free(mi);
1038 return -ENOMEM;
1039 }
1040
1041 add_module(mi, modules);
1042
1043 return 0;
1044 }
1045
read_proc_modules(const char * filename,struct rb_root * modules)1046 static int read_proc_modules(const char *filename, struct rb_root *modules)
1047 {
1048 if (symbol__restricted_filename(filename, "/proc/modules"))
1049 return -1;
1050
1051 if (modules__parse(filename, modules, __read_proc_modules)) {
1052 delete_modules(modules);
1053 return -1;
1054 }
1055
1056 return 0;
1057 }
1058
compare_proc_modules(const char * from,const char * to)1059 int compare_proc_modules(const char *from, const char *to)
1060 {
1061 struct rb_root from_modules = RB_ROOT;
1062 struct rb_root to_modules = RB_ROOT;
1063 struct rb_node *from_node, *to_node;
1064 struct module_info *from_m, *to_m;
1065 int ret = -1;
1066
1067 if (read_proc_modules(from, &from_modules))
1068 return -1;
1069
1070 if (read_proc_modules(to, &to_modules))
1071 goto out_delete_from;
1072
1073 from_node = rb_first(&from_modules);
1074 to_node = rb_first(&to_modules);
1075 while (from_node) {
1076 if (!to_node)
1077 break;
1078
1079 from_m = rb_entry(from_node, struct module_info, rb_node);
1080 to_m = rb_entry(to_node, struct module_info, rb_node);
1081
1082 if (from_m->start != to_m->start ||
1083 strcmp(from_m->name, to_m->name))
1084 break;
1085
1086 from_node = rb_next(from_node);
1087 to_node = rb_next(to_node);
1088 }
1089
1090 if (!from_node && !to_node)
1091 ret = 0;
1092
1093 delete_modules(&to_modules);
1094 out_delete_from:
1095 delete_modules(&from_modules);
1096
1097 return ret;
1098 }
1099
do_validate_kcore_modules(const char * filename,struct maps * kmaps)1100 static int do_validate_kcore_modules(const char *filename, struct maps *kmaps)
1101 {
1102 struct rb_root modules = RB_ROOT;
1103 struct map *old_map;
1104 int err;
1105
1106 err = read_proc_modules(filename, &modules);
1107 if (err)
1108 return err;
1109
1110 maps__for_each_entry(kmaps, old_map) {
1111 struct module_info *mi;
1112
1113 if (!__map__is_kmodule(old_map)) {
1114 continue;
1115 }
1116
1117 /* Module must be in memory at the same address */
1118 mi = find_module(old_map->dso->short_name, &modules);
1119 if (!mi || mi->start != old_map->start) {
1120 err = -EINVAL;
1121 goto out;
1122 }
1123 }
1124 out:
1125 delete_modules(&modules);
1126 return err;
1127 }
1128
1129 /*
1130 * If kallsyms is referenced by name then we look for filename in the same
1131 * directory.
1132 */
filename_from_kallsyms_filename(char * filename,const char * base_name,const char * kallsyms_filename)1133 static bool filename_from_kallsyms_filename(char *filename,
1134 const char *base_name,
1135 const char *kallsyms_filename)
1136 {
1137 char *name;
1138
1139 strcpy(filename, kallsyms_filename);
1140 name = strrchr(filename, '/');
1141 if (!name)
1142 return false;
1143
1144 name += 1;
1145
1146 if (!strcmp(name, "kallsyms")) {
1147 strcpy(name, base_name);
1148 return true;
1149 }
1150
1151 return false;
1152 }
1153
validate_kcore_modules(const char * kallsyms_filename,struct map * map)1154 static int validate_kcore_modules(const char *kallsyms_filename,
1155 struct map *map)
1156 {
1157 struct maps *kmaps = map__kmaps(map);
1158 char modules_filename[PATH_MAX];
1159
1160 if (!kmaps)
1161 return -EINVAL;
1162
1163 if (!filename_from_kallsyms_filename(modules_filename, "modules",
1164 kallsyms_filename))
1165 return -EINVAL;
1166
1167 if (do_validate_kcore_modules(modules_filename, kmaps))
1168 return -EINVAL;
1169
1170 return 0;
1171 }
1172
validate_kcore_addresses(const char * kallsyms_filename,struct map * map)1173 static int validate_kcore_addresses(const char *kallsyms_filename,
1174 struct map *map)
1175 {
1176 struct kmap *kmap = map__kmap(map);
1177
1178 if (!kmap)
1179 return -EINVAL;
1180
1181 if (kmap->ref_reloc_sym && kmap->ref_reloc_sym->name) {
1182 u64 start;
1183
1184 if (kallsyms__get_function_start(kallsyms_filename,
1185 kmap->ref_reloc_sym->name, &start))
1186 return -ENOENT;
1187 if (start != kmap->ref_reloc_sym->addr)
1188 return -EINVAL;
1189 }
1190
1191 return validate_kcore_modules(kallsyms_filename, map);
1192 }
1193
1194 struct kcore_mapfn_data {
1195 struct dso *dso;
1196 struct list_head maps;
1197 };
1198
kcore_mapfn(u64 start,u64 len,u64 pgoff,void * data)1199 static int kcore_mapfn(u64 start, u64 len, u64 pgoff, void *data)
1200 {
1201 struct kcore_mapfn_data *md = data;
1202 struct map *map;
1203
1204 map = map__new2(start, md->dso);
1205 if (map == NULL)
1206 return -ENOMEM;
1207
1208 map->end = map->start + len;
1209 map->pgoff = pgoff;
1210
1211 list_add(&map->node, &md->maps);
1212
1213 return 0;
1214 }
1215
1216 /*
1217 * Merges map into maps by splitting the new map within the existing map
1218 * regions.
1219 */
maps__merge_in(struct maps * kmaps,struct map * new_map)1220 int maps__merge_in(struct maps *kmaps, struct map *new_map)
1221 {
1222 struct map *old_map;
1223 LIST_HEAD(merged);
1224
1225 maps__for_each_entry(kmaps, old_map) {
1226 /* no overload with this one */
1227 if (new_map->end < old_map->start ||
1228 new_map->start >= old_map->end)
1229 continue;
1230
1231 if (new_map->start < old_map->start) {
1232 /*
1233 * |new......
1234 * |old....
1235 */
1236 if (new_map->end < old_map->end) {
1237 /*
1238 * |new......| -> |new..|
1239 * |old....| -> |old....|
1240 */
1241 new_map->end = old_map->start;
1242 } else {
1243 /*
1244 * |new.............| -> |new..| |new..|
1245 * |old....| -> |old....|
1246 */
1247 struct map *m = map__clone(new_map);
1248
1249 if (!m)
1250 return -ENOMEM;
1251
1252 m->end = old_map->start;
1253 list_add_tail(&m->node, &merged);
1254 new_map->pgoff += old_map->end - new_map->start;
1255 new_map->start = old_map->end;
1256 }
1257 } else {
1258 /*
1259 * |new......
1260 * |old....
1261 */
1262 if (new_map->end < old_map->end) {
1263 /*
1264 * |new..| -> x
1265 * |old.........| -> |old.........|
1266 */
1267 map__put(new_map);
1268 new_map = NULL;
1269 break;
1270 } else {
1271 /*
1272 * |new......| -> |new...|
1273 * |old....| -> |old....|
1274 */
1275 new_map->pgoff += old_map->end - new_map->start;
1276 new_map->start = old_map->end;
1277 }
1278 }
1279 }
1280
1281 while (!list_empty(&merged)) {
1282 old_map = list_entry(merged.next, struct map, node);
1283 list_del_init(&old_map->node);
1284 maps__insert(kmaps, old_map);
1285 map__put(old_map);
1286 }
1287
1288 if (new_map) {
1289 maps__insert(kmaps, new_map);
1290 map__put(new_map);
1291 }
1292 return 0;
1293 }
1294
dso__load_kcore(struct dso * dso,struct map * map,const char * kallsyms_filename)1295 static int dso__load_kcore(struct dso *dso, struct map *map,
1296 const char *kallsyms_filename)
1297 {
1298 struct maps *kmaps = map__kmaps(map);
1299 struct kcore_mapfn_data md;
1300 struct map *old_map, *new_map, *replacement_map = NULL, *next;
1301 struct machine *machine;
1302 bool is_64_bit;
1303 int err, fd;
1304 char kcore_filename[PATH_MAX];
1305 u64 stext;
1306
1307 if (!kmaps)
1308 return -EINVAL;
1309
1310 machine = kmaps->machine;
1311
1312 /* This function requires that the map is the kernel map */
1313 if (!__map__is_kernel(map))
1314 return -EINVAL;
1315
1316 if (!filename_from_kallsyms_filename(kcore_filename, "kcore",
1317 kallsyms_filename))
1318 return -EINVAL;
1319
1320 /* Modules and kernel must be present at their original addresses */
1321 if (validate_kcore_addresses(kallsyms_filename, map))
1322 return -EINVAL;
1323
1324 md.dso = dso;
1325 INIT_LIST_HEAD(&md.maps);
1326
1327 fd = open(kcore_filename, O_RDONLY);
1328 if (fd < 0) {
1329 pr_debug("Failed to open %s. Note /proc/kcore requires CAP_SYS_RAWIO capability to access.\n",
1330 kcore_filename);
1331 return -EINVAL;
1332 }
1333
1334 /* Read new maps into temporary lists */
1335 err = file__read_maps(fd, map->prot & PROT_EXEC, kcore_mapfn, &md,
1336 &is_64_bit);
1337 if (err)
1338 goto out_err;
1339 dso->is_64_bit = is_64_bit;
1340
1341 if (list_empty(&md.maps)) {
1342 err = -EINVAL;
1343 goto out_err;
1344 }
1345
1346 /* Remove old maps */
1347 maps__for_each_entry_safe(kmaps, old_map, next) {
1348 /*
1349 * We need to preserve eBPF maps even if they are
1350 * covered by kcore, because we need to access
1351 * eBPF dso for source data.
1352 */
1353 if (old_map != map && !__map__is_bpf_prog(old_map))
1354 maps__remove(kmaps, old_map);
1355 }
1356 machine->trampolines_mapped = false;
1357
1358 /* Find the kernel map using the '_stext' symbol */
1359 if (!kallsyms__get_function_start(kallsyms_filename, "_stext", &stext)) {
1360 u64 replacement_size = 0;
1361
1362 list_for_each_entry(new_map, &md.maps, node) {
1363 u64 new_size = new_map->end - new_map->start;
1364
1365 if (!(stext >= new_map->start && stext < new_map->end))
1366 continue;
1367
1368 /*
1369 * On some architectures, ARM64 for example, the kernel
1370 * text can get allocated inside of the vmalloc segment.
1371 * Select the smallest matching segment, in case stext
1372 * falls within more than one in the list.
1373 */
1374 if (!replacement_map || new_size < replacement_size) {
1375 replacement_map = new_map;
1376 replacement_size = new_size;
1377 }
1378 }
1379 }
1380
1381 if (!replacement_map)
1382 replacement_map = list_entry(md.maps.next, struct map, node);
1383
1384 /* Add new maps */
1385 while (!list_empty(&md.maps)) {
1386 new_map = list_entry(md.maps.next, struct map, node);
1387 list_del_init(&new_map->node);
1388 if (new_map == replacement_map) {
1389 map->start = new_map->start;
1390 map->end = new_map->end;
1391 map->pgoff = new_map->pgoff;
1392 map->map_ip = new_map->map_ip;
1393 map->unmap_ip = new_map->unmap_ip;
1394 /* Ensure maps are correctly ordered */
1395 map__get(map);
1396 maps__remove(kmaps, map);
1397 maps__insert(kmaps, map);
1398 map__put(map);
1399 map__put(new_map);
1400 } else {
1401 /*
1402 * Merge kcore map into existing maps,
1403 * and ensure that current maps (eBPF)
1404 * stay intact.
1405 */
1406 if (maps__merge_in(kmaps, new_map))
1407 goto out_err;
1408 }
1409 }
1410
1411 if (machine__is(machine, "x86_64")) {
1412 u64 addr;
1413
1414 /*
1415 * If one of the corresponding symbols is there, assume the
1416 * entry trampoline maps are too.
1417 */
1418 if (!kallsyms__get_function_start(kallsyms_filename,
1419 ENTRY_TRAMPOLINE_NAME,
1420 &addr))
1421 machine->trampolines_mapped = true;
1422 }
1423
1424 /*
1425 * Set the data type and long name so that kcore can be read via
1426 * dso__data_read_addr().
1427 */
1428 if (dso->kernel == DSO_SPACE__KERNEL_GUEST)
1429 dso->binary_type = DSO_BINARY_TYPE__GUEST_KCORE;
1430 else
1431 dso->binary_type = DSO_BINARY_TYPE__KCORE;
1432 dso__set_long_name(dso, strdup(kcore_filename), true);
1433
1434 close(fd);
1435
1436 if (map->prot & PROT_EXEC)
1437 pr_debug("Using %s for kernel object code\n", kcore_filename);
1438 else
1439 pr_debug("Using %s for kernel data\n", kcore_filename);
1440
1441 return 0;
1442
1443 out_err:
1444 while (!list_empty(&md.maps)) {
1445 map = list_entry(md.maps.next, struct map, node);
1446 list_del_init(&map->node);
1447 map__put(map);
1448 }
1449 close(fd);
1450 return -EINVAL;
1451 }
1452
1453 /*
1454 * If the kernel is relocated at boot time, kallsyms won't match. Compute the
1455 * delta based on the relocation reference symbol.
1456 */
kallsyms__delta(struct kmap * kmap,const char * filename,u64 * delta)1457 static int kallsyms__delta(struct kmap *kmap, const char *filename, u64 *delta)
1458 {
1459 u64 addr;
1460
1461 if (!kmap->ref_reloc_sym || !kmap->ref_reloc_sym->name)
1462 return 0;
1463
1464 if (kallsyms__get_function_start(filename, kmap->ref_reloc_sym->name, &addr))
1465 return -1;
1466
1467 *delta = addr - kmap->ref_reloc_sym->addr;
1468 return 0;
1469 }
1470
__dso__load_kallsyms(struct dso * dso,const char * filename,struct map * map,bool no_kcore)1471 int __dso__load_kallsyms(struct dso *dso, const char *filename,
1472 struct map *map, bool no_kcore)
1473 {
1474 struct kmap *kmap = map__kmap(map);
1475 u64 delta = 0;
1476
1477 if (symbol__restricted_filename(filename, "/proc/kallsyms"))
1478 return -1;
1479
1480 if (!kmap || !kmap->kmaps)
1481 return -1;
1482
1483 if (dso__load_all_kallsyms(dso, filename) < 0)
1484 return -1;
1485
1486 if (kallsyms__delta(kmap, filename, &delta))
1487 return -1;
1488
1489 symbols__fixup_end(&dso->symbols, true);
1490 symbols__fixup_duplicate(&dso->symbols);
1491
1492 if (dso->kernel == DSO_SPACE__KERNEL_GUEST)
1493 dso->symtab_type = DSO_BINARY_TYPE__GUEST_KALLSYMS;
1494 else
1495 dso->symtab_type = DSO_BINARY_TYPE__KALLSYMS;
1496
1497 if (!no_kcore && !dso__load_kcore(dso, map, filename))
1498 return maps__split_kallsyms_for_kcore(kmap->kmaps, dso);
1499 else
1500 return maps__split_kallsyms(kmap->kmaps, dso, delta, map);
1501 }
1502
dso__load_kallsyms(struct dso * dso,const char * filename,struct map * map)1503 int dso__load_kallsyms(struct dso *dso, const char *filename,
1504 struct map *map)
1505 {
1506 return __dso__load_kallsyms(dso, filename, map, false);
1507 }
1508
dso__load_perf_map(const char * map_path,struct dso * dso)1509 static int dso__load_perf_map(const char *map_path, struct dso *dso)
1510 {
1511 char *line = NULL;
1512 size_t n;
1513 FILE *file;
1514 int nr_syms = 0;
1515
1516 file = fopen(map_path, "r");
1517 if (file == NULL)
1518 goto out_failure;
1519
1520 while (!feof(file)) {
1521 u64 start, size;
1522 struct symbol *sym;
1523 int line_len, len;
1524
1525 line_len = getline(&line, &n, file);
1526 if (line_len < 0)
1527 break;
1528
1529 if (!line)
1530 goto out_failure;
1531
1532 line[--line_len] = '\0'; /* \n */
1533
1534 len = hex2u64(line, &start);
1535
1536 len++;
1537 if (len + 2 >= line_len)
1538 continue;
1539
1540 len += hex2u64(line + len, &size);
1541
1542 len++;
1543 if (len + 2 >= line_len)
1544 continue;
1545
1546 sym = symbol__new(start, size, STB_GLOBAL, STT_FUNC, line + len);
1547
1548 if (sym == NULL)
1549 goto out_delete_line;
1550
1551 symbols__insert(&dso->symbols, sym);
1552 nr_syms++;
1553 }
1554
1555 free(line);
1556 fclose(file);
1557
1558 return nr_syms;
1559
1560 out_delete_line:
1561 free(line);
1562 out_failure:
1563 return -1;
1564 }
1565
1566 #ifdef HAVE_LIBBFD_SUPPORT
1567 #define PACKAGE 'perf'
1568 #include <bfd.h>
1569
bfd_symbols__cmpvalue(const void * a,const void * b)1570 static int bfd_symbols__cmpvalue(const void *a, const void *b)
1571 {
1572 const asymbol *as = *(const asymbol **)a, *bs = *(const asymbol **)b;
1573
1574 if (bfd_asymbol_value(as) != bfd_asymbol_value(bs))
1575 return bfd_asymbol_value(as) - bfd_asymbol_value(bs);
1576
1577 return bfd_asymbol_name(as)[0] - bfd_asymbol_name(bs)[0];
1578 }
1579
bfd2elf_binding(asymbol * symbol)1580 static int bfd2elf_binding(asymbol *symbol)
1581 {
1582 if (symbol->flags & BSF_WEAK)
1583 return STB_WEAK;
1584 if (symbol->flags & BSF_GLOBAL)
1585 return STB_GLOBAL;
1586 if (symbol->flags & BSF_LOCAL)
1587 return STB_LOCAL;
1588 return -1;
1589 }
1590
dso__load_bfd_symbols(struct dso * dso,const char * debugfile)1591 int dso__load_bfd_symbols(struct dso *dso, const char *debugfile)
1592 {
1593 int err = -1;
1594 long symbols_size, symbols_count, i;
1595 asection *section;
1596 asymbol **symbols, *sym;
1597 struct symbol *symbol;
1598 bfd *abfd;
1599 u64 start, len;
1600
1601 abfd = bfd_openr(debugfile, NULL);
1602 if (!abfd)
1603 return -1;
1604
1605 if (!bfd_check_format(abfd, bfd_object)) {
1606 pr_debug2("%s: cannot read %s bfd file.\n", __func__,
1607 dso->long_name);
1608 goto out_close;
1609 }
1610
1611 if (bfd_get_flavour(abfd) == bfd_target_elf_flavour)
1612 goto out_close;
1613
1614 symbols_size = bfd_get_symtab_upper_bound(abfd);
1615 if (symbols_size == 0) {
1616 bfd_close(abfd);
1617 return 0;
1618 }
1619
1620 if (symbols_size < 0)
1621 goto out_close;
1622
1623 symbols = malloc(symbols_size);
1624 if (!symbols)
1625 goto out_close;
1626
1627 symbols_count = bfd_canonicalize_symtab(abfd, symbols);
1628 if (symbols_count < 0)
1629 goto out_free;
1630
1631 section = bfd_get_section_by_name(abfd, ".text");
1632 if (section) {
1633 for (i = 0; i < symbols_count; ++i) {
1634 if (!strcmp(bfd_asymbol_name(symbols[i]), "__ImageBase") ||
1635 !strcmp(bfd_asymbol_name(symbols[i]), "__image_base__"))
1636 break;
1637 }
1638 if (i < symbols_count) {
1639 /* PE symbols can only have 4 bytes, so use .text high bits */
1640 dso->text_offset = section->vma - (u32)section->vma;
1641 dso->text_offset += (u32)bfd_asymbol_value(symbols[i]);
1642 } else {
1643 dso->text_offset = section->vma - section->filepos;
1644 }
1645 }
1646
1647 qsort(symbols, symbols_count, sizeof(asymbol *), bfd_symbols__cmpvalue);
1648
1649 #ifdef bfd_get_section
1650 #define bfd_asymbol_section bfd_get_section
1651 #endif
1652 for (i = 0; i < symbols_count; ++i) {
1653 sym = symbols[i];
1654 section = bfd_asymbol_section(sym);
1655 if (bfd2elf_binding(sym) < 0)
1656 continue;
1657
1658 while (i + 1 < symbols_count &&
1659 bfd_asymbol_section(symbols[i + 1]) == section &&
1660 bfd2elf_binding(symbols[i + 1]) < 0)
1661 i++;
1662
1663 if (i + 1 < symbols_count &&
1664 bfd_asymbol_section(symbols[i + 1]) == section)
1665 len = symbols[i + 1]->value - sym->value;
1666 else
1667 len = section->size - sym->value;
1668
1669 start = bfd_asymbol_value(sym) - dso->text_offset;
1670 symbol = symbol__new(start, len, bfd2elf_binding(sym), STT_FUNC,
1671 bfd_asymbol_name(sym));
1672 if (!symbol)
1673 goto out_free;
1674
1675 symbols__insert(&dso->symbols, symbol);
1676 }
1677 #ifdef bfd_get_section
1678 #undef bfd_asymbol_section
1679 #endif
1680
1681 symbols__fixup_end(&dso->symbols, false);
1682 symbols__fixup_duplicate(&dso->symbols);
1683 dso->adjust_symbols = 1;
1684
1685 err = 0;
1686 out_free:
1687 free(symbols);
1688 out_close:
1689 bfd_close(abfd);
1690 return err;
1691 }
1692 #endif
1693
dso__is_compatible_symtab_type(struct dso * dso,bool kmod,enum dso_binary_type type)1694 static bool dso__is_compatible_symtab_type(struct dso *dso, bool kmod,
1695 enum dso_binary_type type)
1696 {
1697 switch (type) {
1698 case DSO_BINARY_TYPE__JAVA_JIT:
1699 case DSO_BINARY_TYPE__DEBUGLINK:
1700 case DSO_BINARY_TYPE__SYSTEM_PATH_DSO:
1701 case DSO_BINARY_TYPE__FEDORA_DEBUGINFO:
1702 case DSO_BINARY_TYPE__UBUNTU_DEBUGINFO:
1703 case DSO_BINARY_TYPE__MIXEDUP_UBUNTU_DEBUGINFO:
1704 case DSO_BINARY_TYPE__BUILDID_DEBUGINFO:
1705 case DSO_BINARY_TYPE__OPENEMBEDDED_DEBUGINFO:
1706 return !kmod && dso->kernel == DSO_SPACE__USER;
1707
1708 case DSO_BINARY_TYPE__KALLSYMS:
1709 case DSO_BINARY_TYPE__VMLINUX:
1710 case DSO_BINARY_TYPE__KCORE:
1711 return dso->kernel == DSO_SPACE__KERNEL;
1712
1713 case DSO_BINARY_TYPE__GUEST_KALLSYMS:
1714 case DSO_BINARY_TYPE__GUEST_VMLINUX:
1715 case DSO_BINARY_TYPE__GUEST_KCORE:
1716 return dso->kernel == DSO_SPACE__KERNEL_GUEST;
1717
1718 case DSO_BINARY_TYPE__GUEST_KMODULE:
1719 case DSO_BINARY_TYPE__GUEST_KMODULE_COMP:
1720 case DSO_BINARY_TYPE__SYSTEM_PATH_KMODULE:
1721 case DSO_BINARY_TYPE__SYSTEM_PATH_KMODULE_COMP:
1722 /*
1723 * kernel modules know their symtab type - it's set when
1724 * creating a module dso in machine__addnew_module_map().
1725 */
1726 return kmod && dso->symtab_type == type;
1727
1728 case DSO_BINARY_TYPE__BUILD_ID_CACHE:
1729 case DSO_BINARY_TYPE__BUILD_ID_CACHE_DEBUGINFO:
1730 return true;
1731
1732 case DSO_BINARY_TYPE__BPF_PROG_INFO:
1733 case DSO_BINARY_TYPE__BPF_IMAGE:
1734 case DSO_BINARY_TYPE__OOL:
1735 case DSO_BINARY_TYPE__NOT_FOUND:
1736 default:
1737 return false;
1738 }
1739 }
1740
1741 /* Checks for the existence of the perf-<pid>.map file in two different
1742 * locations. First, if the process is a separate mount namespace, check in
1743 * that namespace using the pid of the innermost pid namespace. If's not in a
1744 * namespace, or the file can't be found there, try in the mount namespace of
1745 * the tracing process using our view of its pid.
1746 */
dso__find_perf_map(char * filebuf,size_t bufsz,struct nsinfo ** nsip)1747 static int dso__find_perf_map(char *filebuf, size_t bufsz,
1748 struct nsinfo **nsip)
1749 {
1750 struct nscookie nsc;
1751 struct nsinfo *nsi;
1752 struct nsinfo *nnsi;
1753 int rc = -1;
1754
1755 nsi = *nsip;
1756
1757 if (nsi->need_setns) {
1758 snprintf(filebuf, bufsz, "/tmp/perf-%d.map", nsi->nstgid);
1759 nsinfo__mountns_enter(nsi, &nsc);
1760 rc = access(filebuf, R_OK);
1761 nsinfo__mountns_exit(&nsc);
1762 if (rc == 0)
1763 return rc;
1764 }
1765
1766 nnsi = nsinfo__copy(nsi);
1767 if (nnsi) {
1768 nsinfo__put(nsi);
1769
1770 nnsi->need_setns = false;
1771 snprintf(filebuf, bufsz, "/tmp/perf-%d.map", nnsi->tgid);
1772 *nsip = nnsi;
1773 rc = 0;
1774 }
1775
1776 return rc;
1777 }
1778
dso__load(struct dso * dso,struct map * map)1779 int dso__load(struct dso *dso, struct map *map)
1780 {
1781 char *name;
1782 int ret = -1;
1783 u_int i;
1784 struct machine *machine = NULL;
1785 char *root_dir = (char *) "";
1786 int ss_pos = 0;
1787 struct symsrc ss_[2];
1788 struct symsrc *syms_ss = NULL, *runtime_ss = NULL;
1789 bool kmod;
1790 bool perfmap;
1791 struct build_id bid;
1792 struct nscookie nsc;
1793 char newmapname[PATH_MAX];
1794 const char *map_path = dso->long_name;
1795
1796 perfmap = strncmp(dso->name, "/tmp/perf-", 10) == 0;
1797 if (perfmap) {
1798 if (dso->nsinfo && (dso__find_perf_map(newmapname,
1799 sizeof(newmapname), &dso->nsinfo) == 0)) {
1800 map_path = newmapname;
1801 }
1802 }
1803
1804 nsinfo__mountns_enter(dso->nsinfo, &nsc);
1805 pthread_mutex_lock(&dso->lock);
1806
1807 /* check again under the dso->lock */
1808 if (dso__loaded(dso)) {
1809 ret = 1;
1810 goto out;
1811 }
1812
1813 kmod = dso->symtab_type == DSO_BINARY_TYPE__SYSTEM_PATH_KMODULE ||
1814 dso->symtab_type == DSO_BINARY_TYPE__SYSTEM_PATH_KMODULE_COMP ||
1815 dso->symtab_type == DSO_BINARY_TYPE__GUEST_KMODULE ||
1816 dso->symtab_type == DSO_BINARY_TYPE__GUEST_KMODULE_COMP;
1817
1818 if (dso->kernel && !kmod) {
1819 if (dso->kernel == DSO_SPACE__KERNEL)
1820 ret = dso__load_kernel_sym(dso, map);
1821 else if (dso->kernel == DSO_SPACE__KERNEL_GUEST)
1822 ret = dso__load_guest_kernel_sym(dso, map);
1823
1824 machine = map__kmaps(map)->machine;
1825 if (machine__is(machine, "x86_64"))
1826 machine__map_x86_64_entry_trampolines(machine, dso);
1827 goto out;
1828 }
1829
1830 dso->adjust_symbols = 0;
1831
1832 if (perfmap) {
1833 ret = dso__load_perf_map(map_path, dso);
1834 dso->symtab_type = ret > 0 ? DSO_BINARY_TYPE__JAVA_JIT :
1835 DSO_BINARY_TYPE__NOT_FOUND;
1836 goto out;
1837 }
1838
1839 if (machine)
1840 root_dir = machine->root_dir;
1841
1842 name = malloc(PATH_MAX);
1843 if (!name)
1844 goto out;
1845
1846 /*
1847 * Read the build id if possible. This is required for
1848 * DSO_BINARY_TYPE__BUILDID_DEBUGINFO to work
1849 */
1850 if (!dso->has_build_id &&
1851 is_regular_file(dso->long_name)) {
1852 __symbol__join_symfs(name, PATH_MAX, dso->long_name);
1853 if (filename__read_build_id(name, &bid) > 0)
1854 dso__set_build_id(dso, &bid);
1855 }
1856
1857 /*
1858 * Iterate over candidate debug images.
1859 * Keep track of "interesting" ones (those which have a symtab, dynsym,
1860 * and/or opd section) for processing.
1861 */
1862 for (i = 0; i < DSO_BINARY_TYPE__SYMTAB_CNT; i++) {
1863 struct symsrc *ss = &ss_[ss_pos];
1864 bool next_slot = false;
1865 bool is_reg;
1866 bool nsexit;
1867 int bfdrc = -1;
1868 int sirc = -1;
1869
1870 enum dso_binary_type symtab_type = binary_type_symtab[i];
1871
1872 nsexit = (symtab_type == DSO_BINARY_TYPE__BUILD_ID_CACHE ||
1873 symtab_type == DSO_BINARY_TYPE__BUILD_ID_CACHE_DEBUGINFO);
1874
1875 if (!dso__is_compatible_symtab_type(dso, kmod, symtab_type))
1876 continue;
1877
1878 if (dso__read_binary_type_filename(dso, symtab_type,
1879 root_dir, name, PATH_MAX))
1880 continue;
1881
1882 if (nsexit)
1883 nsinfo__mountns_exit(&nsc);
1884
1885 is_reg = is_regular_file(name);
1886 #ifdef HAVE_LIBBFD_SUPPORT
1887 if (is_reg)
1888 bfdrc = dso__load_bfd_symbols(dso, name);
1889 #endif
1890 if (is_reg && bfdrc < 0)
1891 sirc = symsrc__init(ss, dso, name, symtab_type);
1892
1893 if (nsexit)
1894 nsinfo__mountns_enter(dso->nsinfo, &nsc);
1895
1896 if (bfdrc == 0) {
1897 ret = 0;
1898 break;
1899 }
1900
1901 if (!is_reg || sirc < 0)
1902 continue;
1903
1904 if (!syms_ss && symsrc__has_symtab(ss)) {
1905 syms_ss = ss;
1906 next_slot = true;
1907 if (!dso->symsrc_filename)
1908 dso->symsrc_filename = strdup(name);
1909 }
1910
1911 if (!runtime_ss && symsrc__possibly_runtime(ss)) {
1912 runtime_ss = ss;
1913 next_slot = true;
1914 }
1915
1916 if (next_slot) {
1917 ss_pos++;
1918
1919 if (syms_ss && runtime_ss)
1920 break;
1921 } else {
1922 symsrc__destroy(ss);
1923 }
1924
1925 }
1926
1927 if (!runtime_ss && !syms_ss)
1928 goto out_free;
1929
1930 if (runtime_ss && !syms_ss) {
1931 syms_ss = runtime_ss;
1932 }
1933
1934 /* We'll have to hope for the best */
1935 if (!runtime_ss && syms_ss)
1936 runtime_ss = syms_ss;
1937
1938 if (syms_ss)
1939 ret = dso__load_sym(dso, map, syms_ss, runtime_ss, kmod);
1940 else
1941 ret = -1;
1942
1943 if (ret > 0) {
1944 int nr_plt;
1945
1946 nr_plt = dso__synthesize_plt_symbols(dso, runtime_ss);
1947 if (nr_plt > 0)
1948 ret += nr_plt;
1949 }
1950
1951 for (; ss_pos > 0; ss_pos--)
1952 symsrc__destroy(&ss_[ss_pos - 1]);
1953 out_free:
1954 free(name);
1955 if (ret < 0 && strstr(dso->name, " (deleted)") != NULL)
1956 ret = 0;
1957 out:
1958 dso__set_loaded(dso);
1959 pthread_mutex_unlock(&dso->lock);
1960 nsinfo__mountns_exit(&nsc);
1961
1962 return ret;
1963 }
1964
map__strcmp(const void * a,const void * b)1965 static int map__strcmp(const void *a, const void *b)
1966 {
1967 const struct map *ma = *(const struct map **)a, *mb = *(const struct map **)b;
1968 return strcmp(ma->dso->short_name, mb->dso->short_name);
1969 }
1970
map__strcmp_name(const void * name,const void * b)1971 static int map__strcmp_name(const void *name, const void *b)
1972 {
1973 const struct map *map = *(const struct map **)b;
1974 return strcmp(name, map->dso->short_name);
1975 }
1976
__maps__sort_by_name(struct maps * maps)1977 void __maps__sort_by_name(struct maps *maps)
1978 {
1979 qsort(maps->maps_by_name, maps->nr_maps, sizeof(struct map *), map__strcmp);
1980 }
1981
map__groups__sort_by_name_from_rbtree(struct maps * maps)1982 static int map__groups__sort_by_name_from_rbtree(struct maps *maps)
1983 {
1984 struct map *map;
1985 struct map **maps_by_name = realloc(maps->maps_by_name, maps->nr_maps * sizeof(map));
1986 int i = 0;
1987
1988 if (maps_by_name == NULL)
1989 return -1;
1990
1991 maps->maps_by_name = maps_by_name;
1992 maps->nr_maps_allocated = maps->nr_maps;
1993
1994 maps__for_each_entry(maps, map)
1995 maps_by_name[i++] = map;
1996
1997 __maps__sort_by_name(maps);
1998 return 0;
1999 }
2000
__maps__find_by_name(struct maps * maps,const char * name)2001 static struct map *__maps__find_by_name(struct maps *maps, const char *name)
2002 {
2003 struct map **mapp;
2004
2005 if (maps->maps_by_name == NULL &&
2006 map__groups__sort_by_name_from_rbtree(maps))
2007 return NULL;
2008
2009 mapp = bsearch(name, maps->maps_by_name, maps->nr_maps, sizeof(*mapp), map__strcmp_name);
2010 if (mapp)
2011 return *mapp;
2012 return NULL;
2013 }
2014
maps__find_by_name(struct maps * maps,const char * name)2015 struct map *maps__find_by_name(struct maps *maps, const char *name)
2016 {
2017 struct map *map;
2018
2019 down_read(&maps->lock);
2020
2021 if (maps->last_search_by_name && strcmp(maps->last_search_by_name->dso->short_name, name) == 0) {
2022 map = maps->last_search_by_name;
2023 goto out_unlock;
2024 }
2025 /*
2026 * If we have maps->maps_by_name, then the name isn't in the rbtree,
2027 * as maps->maps_by_name mirrors the rbtree when lookups by name are
2028 * made.
2029 */
2030 map = __maps__find_by_name(maps, name);
2031 if (map || maps->maps_by_name != NULL)
2032 goto out_unlock;
2033
2034 /* Fallback to traversing the rbtree... */
2035 maps__for_each_entry(maps, map)
2036 if (strcmp(map->dso->short_name, name) == 0) {
2037 maps->last_search_by_name = map;
2038 goto out_unlock;
2039 }
2040
2041 map = NULL;
2042
2043 out_unlock:
2044 up_read(&maps->lock);
2045 return map;
2046 }
2047
dso__load_vmlinux(struct dso * dso,struct map * map,const char * vmlinux,bool vmlinux_allocated)2048 int dso__load_vmlinux(struct dso *dso, struct map *map,
2049 const char *vmlinux, bool vmlinux_allocated)
2050 {
2051 int err = -1;
2052 struct symsrc ss;
2053 char symfs_vmlinux[PATH_MAX];
2054 enum dso_binary_type symtab_type;
2055
2056 if (vmlinux[0] == '/')
2057 snprintf(symfs_vmlinux, sizeof(symfs_vmlinux), "%s", vmlinux);
2058 else
2059 symbol__join_symfs(symfs_vmlinux, vmlinux);
2060
2061 if (dso->kernel == DSO_SPACE__KERNEL_GUEST)
2062 symtab_type = DSO_BINARY_TYPE__GUEST_VMLINUX;
2063 else
2064 symtab_type = DSO_BINARY_TYPE__VMLINUX;
2065
2066 if (symsrc__init(&ss, dso, symfs_vmlinux, symtab_type))
2067 return -1;
2068
2069 err = dso__load_sym(dso, map, &ss, &ss, 0);
2070 symsrc__destroy(&ss);
2071
2072 if (err > 0) {
2073 if (dso->kernel == DSO_SPACE__KERNEL_GUEST)
2074 dso->binary_type = DSO_BINARY_TYPE__GUEST_VMLINUX;
2075 else
2076 dso->binary_type = DSO_BINARY_TYPE__VMLINUX;
2077 dso__set_long_name(dso, vmlinux, vmlinux_allocated);
2078 dso__set_loaded(dso);
2079 pr_debug("Using %s for symbols\n", symfs_vmlinux);
2080 }
2081
2082 return err;
2083 }
2084
dso__load_vmlinux_path(struct dso * dso,struct map * map)2085 int dso__load_vmlinux_path(struct dso *dso, struct map *map)
2086 {
2087 int i, err = 0;
2088 char *filename = NULL;
2089
2090 pr_debug("Looking at the vmlinux_path (%d entries long)\n",
2091 vmlinux_path__nr_entries + 1);
2092
2093 for (i = 0; i < vmlinux_path__nr_entries; ++i) {
2094 err = dso__load_vmlinux(dso, map, vmlinux_path[i], false);
2095 if (err > 0)
2096 goto out;
2097 }
2098
2099 if (!symbol_conf.ignore_vmlinux_buildid)
2100 filename = dso__build_id_filename(dso, NULL, 0, false);
2101 if (filename != NULL) {
2102 err = dso__load_vmlinux(dso, map, filename, true);
2103 if (err > 0)
2104 goto out;
2105 free(filename);
2106 }
2107 out:
2108 return err;
2109 }
2110
visible_dir_filter(const char * name,struct dirent * d)2111 static bool visible_dir_filter(const char *name, struct dirent *d)
2112 {
2113 if (d->d_type != DT_DIR)
2114 return false;
2115 return lsdir_no_dot_filter(name, d);
2116 }
2117
find_matching_kcore(struct map * map,char * dir,size_t dir_sz)2118 static int find_matching_kcore(struct map *map, char *dir, size_t dir_sz)
2119 {
2120 char kallsyms_filename[PATH_MAX];
2121 int ret = -1;
2122 struct strlist *dirs;
2123 struct str_node *nd;
2124
2125 dirs = lsdir(dir, visible_dir_filter);
2126 if (!dirs)
2127 return -1;
2128
2129 strlist__for_each_entry(nd, dirs) {
2130 scnprintf(kallsyms_filename, sizeof(kallsyms_filename),
2131 "%s/%s/kallsyms", dir, nd->s);
2132 if (!validate_kcore_addresses(kallsyms_filename, map)) {
2133 strlcpy(dir, kallsyms_filename, dir_sz);
2134 ret = 0;
2135 break;
2136 }
2137 }
2138
2139 strlist__delete(dirs);
2140
2141 return ret;
2142 }
2143
2144 /*
2145 * Use open(O_RDONLY) to check readability directly instead of access(R_OK)
2146 * since access(R_OK) only checks with real UID/GID but open() use effective
2147 * UID/GID and actual capabilities (e.g. /proc/kcore requires CAP_SYS_RAWIO).
2148 */
filename__readable(const char * file)2149 static bool filename__readable(const char *file)
2150 {
2151 int fd = open(file, O_RDONLY);
2152 if (fd < 0)
2153 return false;
2154 close(fd);
2155 return true;
2156 }
2157
dso__find_kallsyms(struct dso * dso,struct map * map)2158 static char *dso__find_kallsyms(struct dso *dso, struct map *map)
2159 {
2160 struct build_id bid;
2161 char sbuild_id[SBUILD_ID_SIZE];
2162 bool is_host = false;
2163 char path[PATH_MAX];
2164
2165 if (!dso->has_build_id) {
2166 /*
2167 * Last resort, if we don't have a build-id and couldn't find
2168 * any vmlinux file, try the running kernel kallsyms table.
2169 */
2170 goto proc_kallsyms;
2171 }
2172
2173 if (sysfs__read_build_id("/sys/kernel/notes", &bid) == 0)
2174 is_host = dso__build_id_equal(dso, &bid);
2175
2176 /* Try a fast path for /proc/kallsyms if possible */
2177 if (is_host) {
2178 /*
2179 * Do not check the build-id cache, unless we know we cannot use
2180 * /proc/kcore or module maps don't match to /proc/kallsyms.
2181 * To check readability of /proc/kcore, do not use access(R_OK)
2182 * since /proc/kcore requires CAP_SYS_RAWIO to read and access
2183 * can't check it.
2184 */
2185 if (filename__readable("/proc/kcore") &&
2186 !validate_kcore_addresses("/proc/kallsyms", map))
2187 goto proc_kallsyms;
2188 }
2189
2190 build_id__sprintf(&dso->bid, sbuild_id);
2191
2192 /* Find kallsyms in build-id cache with kcore */
2193 scnprintf(path, sizeof(path), "%s/%s/%s",
2194 buildid_dir, DSO__NAME_KCORE, sbuild_id);
2195
2196 if (!find_matching_kcore(map, path, sizeof(path)))
2197 return strdup(path);
2198
2199 /* Use current /proc/kallsyms if possible */
2200 if (is_host) {
2201 proc_kallsyms:
2202 return strdup("/proc/kallsyms");
2203 }
2204
2205 /* Finally, find a cache of kallsyms */
2206 if (!build_id_cache__kallsyms_path(sbuild_id, path, sizeof(path))) {
2207 pr_err("No kallsyms or vmlinux with build-id %s was found\n",
2208 sbuild_id);
2209 return NULL;
2210 }
2211
2212 return strdup(path);
2213 }
2214
dso__load_kernel_sym(struct dso * dso,struct map * map)2215 static int dso__load_kernel_sym(struct dso *dso, struct map *map)
2216 {
2217 int err;
2218 const char *kallsyms_filename = NULL;
2219 char *kallsyms_allocated_filename = NULL;
2220 char *filename = NULL;
2221
2222 /*
2223 * Step 1: if the user specified a kallsyms or vmlinux filename, use
2224 * it and only it, reporting errors to the user if it cannot be used.
2225 *
2226 * For instance, try to analyse an ARM perf.data file _without_ a
2227 * build-id, or if the user specifies the wrong path to the right
2228 * vmlinux file, obviously we can't fallback to another vmlinux (a
2229 * x86_86 one, on the machine where analysis is being performed, say),
2230 * or worse, /proc/kallsyms.
2231 *
2232 * If the specified file _has_ a build-id and there is a build-id
2233 * section in the perf.data file, we will still do the expected
2234 * validation in dso__load_vmlinux and will bail out if they don't
2235 * match.
2236 */
2237 if (symbol_conf.kallsyms_name != NULL) {
2238 kallsyms_filename = symbol_conf.kallsyms_name;
2239 goto do_kallsyms;
2240 }
2241
2242 if (!symbol_conf.ignore_vmlinux && symbol_conf.vmlinux_name != NULL) {
2243 return dso__load_vmlinux(dso, map, symbol_conf.vmlinux_name, false);
2244 }
2245
2246 /*
2247 * Before checking on common vmlinux locations, check if it's
2248 * stored as standard build id binary (not kallsyms) under
2249 * .debug cache.
2250 */
2251 if (!symbol_conf.ignore_vmlinux_buildid)
2252 filename = __dso__build_id_filename(dso, NULL, 0, false, false);
2253 if (filename != NULL) {
2254 err = dso__load_vmlinux(dso, map, filename, true);
2255 if (err > 0)
2256 return err;
2257 free(filename);
2258 }
2259
2260 if (!symbol_conf.ignore_vmlinux && vmlinux_path != NULL) {
2261 err = dso__load_vmlinux_path(dso, map);
2262 if (err > 0)
2263 return err;
2264 }
2265
2266 /* do not try local files if a symfs was given */
2267 if (symbol_conf.symfs[0] != 0)
2268 return -1;
2269
2270 kallsyms_allocated_filename = dso__find_kallsyms(dso, map);
2271 if (!kallsyms_allocated_filename)
2272 return -1;
2273
2274 kallsyms_filename = kallsyms_allocated_filename;
2275
2276 do_kallsyms:
2277 err = dso__load_kallsyms(dso, kallsyms_filename, map);
2278 if (err > 0)
2279 pr_debug("Using %s for symbols\n", kallsyms_filename);
2280 free(kallsyms_allocated_filename);
2281
2282 if (err > 0 && !dso__is_kcore(dso)) {
2283 dso->binary_type = DSO_BINARY_TYPE__KALLSYMS;
2284 dso__set_long_name(dso, DSO__NAME_KALLSYMS, false);
2285 map__fixup_start(map);
2286 map__fixup_end(map);
2287 }
2288
2289 return err;
2290 }
2291
dso__load_guest_kernel_sym(struct dso * dso,struct map * map)2292 static int dso__load_guest_kernel_sym(struct dso *dso, struct map *map)
2293 {
2294 int err;
2295 const char *kallsyms_filename = NULL;
2296 struct machine *machine = map__kmaps(map)->machine;
2297 char path[PATH_MAX];
2298
2299 if (machine__is_default_guest(machine)) {
2300 /*
2301 * if the user specified a vmlinux filename, use it and only
2302 * it, reporting errors to the user if it cannot be used.
2303 * Or use file guest_kallsyms inputted by user on commandline
2304 */
2305 if (symbol_conf.default_guest_vmlinux_name != NULL) {
2306 err = dso__load_vmlinux(dso, map,
2307 symbol_conf.default_guest_vmlinux_name,
2308 false);
2309 return err;
2310 }
2311
2312 kallsyms_filename = symbol_conf.default_guest_kallsyms;
2313 if (!kallsyms_filename)
2314 return -1;
2315 } else {
2316 sprintf(path, "%s/proc/kallsyms", machine->root_dir);
2317 kallsyms_filename = path;
2318 }
2319
2320 err = dso__load_kallsyms(dso, kallsyms_filename, map);
2321 if (err > 0)
2322 pr_debug("Using %s for symbols\n", kallsyms_filename);
2323 if (err > 0 && !dso__is_kcore(dso)) {
2324 dso->binary_type = DSO_BINARY_TYPE__GUEST_KALLSYMS;
2325 dso__set_long_name(dso, machine->mmap_name, false);
2326 map__fixup_start(map);
2327 map__fixup_end(map);
2328 }
2329
2330 return err;
2331 }
2332
vmlinux_path__exit(void)2333 static void vmlinux_path__exit(void)
2334 {
2335 while (--vmlinux_path__nr_entries >= 0)
2336 zfree(&vmlinux_path[vmlinux_path__nr_entries]);
2337 vmlinux_path__nr_entries = 0;
2338
2339 zfree(&vmlinux_path);
2340 }
2341
2342 static const char * const vmlinux_paths[] = {
2343 "vmlinux",
2344 "/boot/vmlinux"
2345 };
2346
2347 static const char * const vmlinux_paths_upd[] = {
2348 "/boot/vmlinux-%s",
2349 "/usr/lib/debug/boot/vmlinux-%s",
2350 "/lib/modules/%s/build/vmlinux",
2351 "/usr/lib/debug/lib/modules/%s/vmlinux",
2352 "/usr/lib/debug/boot/vmlinux-%s.debug"
2353 };
2354
vmlinux_path__add(const char * new_entry)2355 static int vmlinux_path__add(const char *new_entry)
2356 {
2357 vmlinux_path[vmlinux_path__nr_entries] = strdup(new_entry);
2358 if (vmlinux_path[vmlinux_path__nr_entries] == NULL)
2359 return -1;
2360 ++vmlinux_path__nr_entries;
2361
2362 return 0;
2363 }
2364
vmlinux_path__init(struct perf_env * env)2365 static int vmlinux_path__init(struct perf_env *env)
2366 {
2367 struct utsname uts;
2368 char bf[PATH_MAX];
2369 char *kernel_version;
2370 unsigned int i;
2371
2372 vmlinux_path = malloc(sizeof(char *) * (ARRAY_SIZE(vmlinux_paths) +
2373 ARRAY_SIZE(vmlinux_paths_upd)));
2374 if (vmlinux_path == NULL)
2375 return -1;
2376
2377 for (i = 0; i < ARRAY_SIZE(vmlinux_paths); i++)
2378 if (vmlinux_path__add(vmlinux_paths[i]) < 0)
2379 goto out_fail;
2380
2381 /* only try kernel version if no symfs was given */
2382 if (symbol_conf.symfs[0] != 0)
2383 return 0;
2384
2385 if (env) {
2386 kernel_version = env->os_release;
2387 } else {
2388 if (uname(&uts) < 0)
2389 goto out_fail;
2390
2391 kernel_version = uts.release;
2392 }
2393
2394 for (i = 0; i < ARRAY_SIZE(vmlinux_paths_upd); i++) {
2395 snprintf(bf, sizeof(bf), vmlinux_paths_upd[i], kernel_version);
2396 if (vmlinux_path__add(bf) < 0)
2397 goto out_fail;
2398 }
2399
2400 return 0;
2401
2402 out_fail:
2403 vmlinux_path__exit();
2404 return -1;
2405 }
2406
setup_list(struct strlist ** list,const char * list_str,const char * list_name)2407 int setup_list(struct strlist **list, const char *list_str,
2408 const char *list_name)
2409 {
2410 if (list_str == NULL)
2411 return 0;
2412
2413 *list = strlist__new(list_str, NULL);
2414 if (!*list) {
2415 pr_err("problems parsing %s list\n", list_name);
2416 return -1;
2417 }
2418
2419 symbol_conf.has_filter = true;
2420 return 0;
2421 }
2422
setup_intlist(struct intlist ** list,const char * list_str,const char * list_name)2423 int setup_intlist(struct intlist **list, const char *list_str,
2424 const char *list_name)
2425 {
2426 if (list_str == NULL)
2427 return 0;
2428
2429 *list = intlist__new(list_str);
2430 if (!*list) {
2431 pr_err("problems parsing %s list\n", list_name);
2432 return -1;
2433 }
2434 return 0;
2435 }
2436
setup_addrlist(struct intlist ** addr_list,struct strlist * sym_list)2437 static int setup_addrlist(struct intlist **addr_list, struct strlist *sym_list)
2438 {
2439 struct str_node *pos, *tmp;
2440 unsigned long val;
2441 char *sep;
2442 const char *end;
2443 int i = 0, err;
2444
2445 *addr_list = intlist__new(NULL);
2446 if (!*addr_list)
2447 return -1;
2448
2449 strlist__for_each_entry_safe(pos, tmp, sym_list) {
2450 errno = 0;
2451 val = strtoul(pos->s, &sep, 16);
2452 if (errno || (sep == pos->s))
2453 continue;
2454
2455 if (*sep != '\0') {
2456 end = pos->s + strlen(pos->s) - 1;
2457 while (end >= sep && isspace(*end))
2458 end--;
2459
2460 if (end >= sep)
2461 continue;
2462 }
2463
2464 err = intlist__add(*addr_list, val);
2465 if (err)
2466 break;
2467
2468 strlist__remove(sym_list, pos);
2469 i++;
2470 }
2471
2472 if (i == 0) {
2473 intlist__delete(*addr_list);
2474 *addr_list = NULL;
2475 }
2476
2477 return 0;
2478 }
2479
symbol__read_kptr_restrict(void)2480 static bool symbol__read_kptr_restrict(void)
2481 {
2482 bool value = false;
2483 FILE *fp = fopen("/proc/sys/kernel/kptr_restrict", "r");
2484
2485 if (fp != NULL) {
2486 char line[8];
2487
2488 if (fgets(line, sizeof(line), fp) != NULL)
2489 value = perf_cap__capable(CAP_SYSLOG) ?
2490 (atoi(line) >= 2) :
2491 (atoi(line) != 0);
2492
2493 fclose(fp);
2494 }
2495
2496 /* Per kernel/kallsyms.c:
2497 * we also restrict when perf_event_paranoid > 1 w/o CAP_SYSLOG
2498 */
2499 if (perf_event_paranoid() > 1 && !perf_cap__capable(CAP_SYSLOG))
2500 value = true;
2501
2502 return value;
2503 }
2504
symbol__annotation_init(void)2505 int symbol__annotation_init(void)
2506 {
2507 if (symbol_conf.init_annotation)
2508 return 0;
2509
2510 if (symbol_conf.initialized) {
2511 pr_err("Annotation needs to be init before symbol__init()\n");
2512 return -1;
2513 }
2514
2515 symbol_conf.priv_size += sizeof(struct annotation);
2516 symbol_conf.init_annotation = true;
2517 return 0;
2518 }
2519
symbol__init(struct perf_env * env)2520 int symbol__init(struct perf_env *env)
2521 {
2522 const char *symfs;
2523
2524 if (symbol_conf.initialized)
2525 return 0;
2526
2527 symbol_conf.priv_size = PERF_ALIGN(symbol_conf.priv_size, sizeof(u64));
2528
2529 symbol__elf_init();
2530
2531 if (symbol_conf.sort_by_name)
2532 symbol_conf.priv_size += (sizeof(struct symbol_name_rb_node) -
2533 sizeof(struct symbol));
2534
2535 if (symbol_conf.try_vmlinux_path && vmlinux_path__init(env) < 0)
2536 return -1;
2537
2538 if (symbol_conf.field_sep && *symbol_conf.field_sep == '.') {
2539 pr_err("'.' is the only non valid --field-separator argument\n");
2540 return -1;
2541 }
2542
2543 if (setup_list(&symbol_conf.dso_list,
2544 symbol_conf.dso_list_str, "dso") < 0)
2545 return -1;
2546
2547 if (setup_list(&symbol_conf.comm_list,
2548 symbol_conf.comm_list_str, "comm") < 0)
2549 goto out_free_dso_list;
2550
2551 if (setup_intlist(&symbol_conf.pid_list,
2552 symbol_conf.pid_list_str, "pid") < 0)
2553 goto out_free_comm_list;
2554
2555 if (setup_intlist(&symbol_conf.tid_list,
2556 symbol_conf.tid_list_str, "tid") < 0)
2557 goto out_free_pid_list;
2558
2559 if (setup_list(&symbol_conf.sym_list,
2560 symbol_conf.sym_list_str, "symbol") < 0)
2561 goto out_free_tid_list;
2562
2563 if (symbol_conf.sym_list &&
2564 setup_addrlist(&symbol_conf.addr_list, symbol_conf.sym_list) < 0)
2565 goto out_free_sym_list;
2566
2567 if (setup_list(&symbol_conf.bt_stop_list,
2568 symbol_conf.bt_stop_list_str, "symbol") < 0)
2569 goto out_free_sym_list;
2570
2571 /*
2572 * A path to symbols of "/" is identical to ""
2573 * reset here for simplicity.
2574 */
2575 symfs = realpath(symbol_conf.symfs, NULL);
2576 if (symfs == NULL)
2577 symfs = symbol_conf.symfs;
2578 if (strcmp(symfs, "/") == 0)
2579 symbol_conf.symfs = "";
2580 if (symfs != symbol_conf.symfs)
2581 free((void *)symfs);
2582
2583 symbol_conf.kptr_restrict = symbol__read_kptr_restrict();
2584
2585 symbol_conf.initialized = true;
2586 return 0;
2587
2588 out_free_sym_list:
2589 strlist__delete(symbol_conf.sym_list);
2590 intlist__delete(symbol_conf.addr_list);
2591 out_free_tid_list:
2592 intlist__delete(symbol_conf.tid_list);
2593 out_free_pid_list:
2594 intlist__delete(symbol_conf.pid_list);
2595 out_free_comm_list:
2596 strlist__delete(symbol_conf.comm_list);
2597 out_free_dso_list:
2598 strlist__delete(symbol_conf.dso_list);
2599 return -1;
2600 }
2601
symbol__exit(void)2602 void symbol__exit(void)
2603 {
2604 if (!symbol_conf.initialized)
2605 return;
2606 strlist__delete(symbol_conf.bt_stop_list);
2607 strlist__delete(symbol_conf.sym_list);
2608 strlist__delete(symbol_conf.dso_list);
2609 strlist__delete(symbol_conf.comm_list);
2610 intlist__delete(symbol_conf.tid_list);
2611 intlist__delete(symbol_conf.pid_list);
2612 intlist__delete(symbol_conf.addr_list);
2613 vmlinux_path__exit();
2614 symbol_conf.sym_list = symbol_conf.dso_list = symbol_conf.comm_list = NULL;
2615 symbol_conf.bt_stop_list = NULL;
2616 symbol_conf.initialized = false;
2617 }
2618
symbol__config_symfs(const struct option * opt __maybe_unused,const char * dir,int unset __maybe_unused)2619 int symbol__config_symfs(const struct option *opt __maybe_unused,
2620 const char *dir, int unset __maybe_unused)
2621 {
2622 char *bf = NULL;
2623 int ret;
2624
2625 symbol_conf.symfs = strdup(dir);
2626 if (symbol_conf.symfs == NULL)
2627 return -ENOMEM;
2628
2629 /* skip the locally configured cache if a symfs is given, and
2630 * config buildid dir to symfs/.debug
2631 */
2632 ret = asprintf(&bf, "%s/%s", dir, ".debug");
2633 if (ret < 0)
2634 return -ENOMEM;
2635
2636 set_buildid_dir(bf);
2637
2638 free(bf);
2639 return 0;
2640 }
2641
mem_info__get(struct mem_info * mi)2642 struct mem_info *mem_info__get(struct mem_info *mi)
2643 {
2644 if (mi)
2645 refcount_inc(&mi->refcnt);
2646 return mi;
2647 }
2648
mem_info__put(struct mem_info * mi)2649 void mem_info__put(struct mem_info *mi)
2650 {
2651 if (mi && refcount_dec_and_test(&mi->refcnt))
2652 free(mi);
2653 }
2654
mem_info__new(void)2655 struct mem_info *mem_info__new(void)
2656 {
2657 struct mem_info *mi = zalloc(sizeof(*mi));
2658
2659 if (mi)
2660 refcount_set(&mi->refcnt, 1);
2661 return mi;
2662 }
2663