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 "mem-info.h"
31 #include "symsrc.h"
32 #include "strlist.h"
33 #include "intlist.h"
34 #include "namespaces.h"
35 #include "header.h"
36 #include "path.h"
37 #include <linux/ctype.h>
38 #include <linux/zalloc.h>
39
40 #include <elf.h>
41 #include <limits.h>
42 #include <symbol/kallsyms.h>
43 #include <sys/utsname.h>
44
45 static int dso__load_kernel_sym(struct dso *dso, struct map *map);
46 static int dso__load_guest_kernel_sym(struct dso *dso, struct map *map);
47 static bool symbol__is_idle(const char *name);
48
49 int vmlinux_path__nr_entries;
50 char **vmlinux_path;
51
52 struct symbol_conf symbol_conf = {
53 .nanosecs = false,
54 .use_modules = true,
55 .try_vmlinux_path = true,
56 .demangle = true,
57 .demangle_kernel = false,
58 .cumulate_callchain = true,
59 .time_quantum = 100 * NSEC_PER_MSEC, /* 100ms */
60 .show_hist_headers = true,
61 .symfs = "",
62 .event_group = true,
63 .inline_name = true,
64 .res_sample = 0,
65 };
66
67 struct map_list_node {
68 struct list_head node;
69 struct map *map;
70 };
71
map_list_node__new(void)72 static struct map_list_node *map_list_node__new(void)
73 {
74 return malloc(sizeof(struct map_list_node));
75 }
76
77 static enum dso_binary_type binary_type_symtab[] = {
78 DSO_BINARY_TYPE__KALLSYMS,
79 DSO_BINARY_TYPE__GUEST_KALLSYMS,
80 DSO_BINARY_TYPE__JAVA_JIT,
81 DSO_BINARY_TYPE__DEBUGLINK,
82 DSO_BINARY_TYPE__BUILD_ID_CACHE,
83 DSO_BINARY_TYPE__BUILD_ID_CACHE_DEBUGINFO,
84 DSO_BINARY_TYPE__FEDORA_DEBUGINFO,
85 DSO_BINARY_TYPE__UBUNTU_DEBUGINFO,
86 DSO_BINARY_TYPE__BUILDID_DEBUGINFO,
87 DSO_BINARY_TYPE__SYSTEM_PATH_DSO,
88 DSO_BINARY_TYPE__GUEST_KMODULE,
89 DSO_BINARY_TYPE__GUEST_KMODULE_COMP,
90 DSO_BINARY_TYPE__SYSTEM_PATH_KMODULE,
91 DSO_BINARY_TYPE__SYSTEM_PATH_KMODULE_COMP,
92 DSO_BINARY_TYPE__OPENEMBEDDED_DEBUGINFO,
93 DSO_BINARY_TYPE__MIXEDUP_UBUNTU_DEBUGINFO,
94 DSO_BINARY_TYPE__NOT_FOUND,
95 };
96
97 #define DSO_BINARY_TYPE__SYMTAB_CNT ARRAY_SIZE(binary_type_symtab)
98
symbol_type__filter(char symbol_type)99 static bool symbol_type__filter(char symbol_type)
100 {
101 symbol_type = toupper(symbol_type);
102 return symbol_type == 'T' || symbol_type == 'W' || symbol_type == 'D' || symbol_type == 'B';
103 }
104
prefix_underscores_count(const char * str)105 static int prefix_underscores_count(const char *str)
106 {
107 const char *tail = str;
108
109 while (*tail == '_')
110 tail++;
111
112 return tail - str;
113 }
114
arch__normalize_symbol_name(const char * name)115 const char * __weak arch__normalize_symbol_name(const char *name)
116 {
117 return name;
118 }
119
arch__compare_symbol_names(const char * namea,const char * nameb)120 int __weak arch__compare_symbol_names(const char *namea, const char *nameb)
121 {
122 return strcmp(namea, nameb);
123 }
124
arch__compare_symbol_names_n(const char * namea,const char * nameb,unsigned int n)125 int __weak arch__compare_symbol_names_n(const char *namea, const char *nameb,
126 unsigned int n)
127 {
128 return strncmp(namea, nameb, n);
129 }
130
arch__choose_best_symbol(struct symbol * syma,struct symbol * symb __maybe_unused)131 int __weak arch__choose_best_symbol(struct symbol *syma,
132 struct symbol *symb __maybe_unused)
133 {
134 /* Avoid "SyS" kernel syscall aliases */
135 if (strlen(syma->name) >= 3 && !strncmp(syma->name, "SyS", 3))
136 return SYMBOL_B;
137 if (strlen(syma->name) >= 10 && !strncmp(syma->name, "compat_SyS", 10))
138 return SYMBOL_B;
139
140 return SYMBOL_A;
141 }
142
choose_best_symbol(struct symbol * syma,struct symbol * symb)143 static int choose_best_symbol(struct symbol *syma, struct symbol *symb)
144 {
145 s64 a;
146 s64 b;
147 size_t na, nb;
148
149 /* Prefer a symbol with non zero length */
150 a = syma->end - syma->start;
151 b = symb->end - symb->start;
152 if ((b == 0) && (a > 0))
153 return SYMBOL_A;
154 else if ((a == 0) && (b > 0))
155 return SYMBOL_B;
156
157 if (syma->type != symb->type) {
158 if (syma->type == STT_NOTYPE)
159 return SYMBOL_B;
160 if (symb->type == STT_NOTYPE)
161 return SYMBOL_A;
162 }
163
164 /* Prefer a non weak symbol over a weak one */
165 a = syma->binding == STB_WEAK;
166 b = symb->binding == STB_WEAK;
167 if (b && !a)
168 return SYMBOL_A;
169 if (a && !b)
170 return SYMBOL_B;
171
172 /* Prefer a global symbol over a non global one */
173 a = syma->binding == STB_GLOBAL;
174 b = symb->binding == STB_GLOBAL;
175 if (a && !b)
176 return SYMBOL_A;
177 if (b && !a)
178 return SYMBOL_B;
179
180 /* Prefer a symbol with less underscores */
181 a = prefix_underscores_count(syma->name);
182 b = prefix_underscores_count(symb->name);
183 if (b > a)
184 return SYMBOL_A;
185 else if (a > b)
186 return SYMBOL_B;
187
188 /* Choose the symbol with the longest name */
189 na = strlen(syma->name);
190 nb = strlen(symb->name);
191 if (na > nb)
192 return SYMBOL_A;
193 else if (na < nb)
194 return SYMBOL_B;
195
196 return arch__choose_best_symbol(syma, symb);
197 }
198
symbols__fixup_duplicate(struct rb_root_cached * symbols)199 void symbols__fixup_duplicate(struct rb_root_cached *symbols)
200 {
201 struct rb_node *nd;
202 struct symbol *curr, *next;
203
204 if (symbol_conf.allow_aliases)
205 return;
206
207 nd = rb_first_cached(symbols);
208
209 while (nd) {
210 curr = rb_entry(nd, struct symbol, rb_node);
211 again:
212 nd = rb_next(&curr->rb_node);
213 if (!nd)
214 break;
215
216 next = rb_entry(nd, struct symbol, rb_node);
217 if (curr->start != next->start)
218 continue;
219
220 if (choose_best_symbol(curr, next) == SYMBOL_A) {
221 if (next->type == STT_GNU_IFUNC)
222 curr->ifunc_alias = true;
223 rb_erase_cached(&next->rb_node, symbols);
224 symbol__delete(next);
225 goto again;
226 } else {
227 if (curr->type == STT_GNU_IFUNC)
228 next->ifunc_alias = true;
229 nd = rb_next(&curr->rb_node);
230 rb_erase_cached(&curr->rb_node, symbols);
231 symbol__delete(curr);
232 }
233 }
234 }
235
236 /* Update zero-sized symbols using the address of the next symbol */
symbols__fixup_end(struct rb_root_cached * symbols,bool is_kallsyms)237 void symbols__fixup_end(struct rb_root_cached *symbols, bool is_kallsyms)
238 {
239 struct rb_node *nd, *prevnd = rb_first_cached(symbols);
240 struct symbol *curr, *prev;
241
242 if (prevnd == NULL)
243 return;
244
245 curr = rb_entry(prevnd, struct symbol, rb_node);
246
247 for (nd = rb_next(prevnd); nd; nd = rb_next(nd)) {
248 prev = curr;
249 curr = rb_entry(nd, struct symbol, rb_node);
250
251 /*
252 * On some architecture kernel text segment start is located at
253 * some low memory address, while modules are located at high
254 * memory addresses (or vice versa). The gap between end of
255 * kernel text segment and beginning of first module's text
256 * segment is very big. Therefore do not fill this gap and do
257 * not assign it to the kernel dso map (kallsyms).
258 *
259 * Also BPF code can be allocated separately from text segments
260 * and modules. So the last entry in a module should not fill
261 * the gap too.
262 *
263 * In kallsyms, it determines module symbols using '[' character
264 * like in:
265 * ffffffffc1937000 T hdmi_driver_init [snd_hda_codec_hdmi]
266 */
267 if (prev->end == prev->start) {
268 const char *prev_mod;
269 const char *curr_mod;
270
271 if (!is_kallsyms) {
272 prev->end = curr->start;
273 continue;
274 }
275
276 prev_mod = strchr(prev->name, '[');
277 curr_mod = strchr(curr->name, '[');
278
279 /* Last kernel/module symbol mapped to end of page */
280 if (!prev_mod != !curr_mod)
281 prev->end = roundup(prev->end + 4096, 4096);
282 /* Last symbol in the previous module */
283 else if (prev_mod && strcmp(prev_mod, curr_mod))
284 prev->end = roundup(prev->end + 4096, 4096);
285 else
286 prev->end = curr->start;
287
288 pr_debug4("%s sym:%s end:%#" PRIx64 "\n",
289 __func__, prev->name, prev->end);
290 }
291 }
292
293 /* Last entry */
294 if (curr->end == curr->start)
295 curr->end = roundup(curr->start, 4096) + 4096;
296 }
297
symbol__new(u64 start,u64 len,u8 binding,u8 type,const char * name)298 struct symbol *symbol__new(u64 start, u64 len, u8 binding, u8 type, const char *name)
299 {
300 size_t namelen = strlen(name) + 1;
301 struct symbol *sym = calloc(1, (symbol_conf.priv_size +
302 sizeof(*sym) + namelen));
303 if (sym == NULL)
304 return NULL;
305
306 if (symbol_conf.priv_size) {
307 if (symbol_conf.init_annotation) {
308 struct annotation *notes = (void *)sym;
309 annotation__init(notes);
310 }
311 sym = ((void *)sym) + symbol_conf.priv_size;
312 }
313
314 sym->start = start;
315 sym->end = len ? start + len : start;
316 sym->type = type;
317 sym->binding = binding;
318 sym->namelen = namelen - 1;
319
320 pr_debug4("%s: %s %#" PRIx64 "-%#" PRIx64 "\n",
321 __func__, name, start, sym->end);
322 memcpy(sym->name, name, namelen);
323
324 return sym;
325 }
326
symbol__delete(struct symbol * sym)327 void symbol__delete(struct symbol *sym)
328 {
329 if (symbol_conf.priv_size) {
330 if (symbol_conf.init_annotation) {
331 struct annotation *notes = symbol__annotation(sym);
332
333 annotation__exit(notes);
334 }
335 }
336 free(((void *)sym) - symbol_conf.priv_size);
337 }
338
symbols__delete(struct rb_root_cached * symbols)339 void symbols__delete(struct rb_root_cached *symbols)
340 {
341 struct symbol *pos;
342 struct rb_node *next = rb_first_cached(symbols);
343
344 while (next) {
345 pos = rb_entry(next, struct symbol, rb_node);
346 next = rb_next(&pos->rb_node);
347 rb_erase_cached(&pos->rb_node, symbols);
348 symbol__delete(pos);
349 }
350 }
351
__symbols__insert(struct rb_root_cached * symbols,struct symbol * sym,bool kernel)352 void __symbols__insert(struct rb_root_cached *symbols,
353 struct symbol *sym, bool kernel)
354 {
355 struct rb_node **p = &symbols->rb_root.rb_node;
356 struct rb_node *parent = NULL;
357 const u64 ip = sym->start;
358 struct symbol *s;
359 bool leftmost = true;
360
361 if (kernel) {
362 const char *name = sym->name;
363 /*
364 * ppc64 uses function descriptors and appends a '.' to the
365 * start of every instruction address. Remove it.
366 */
367 if (name[0] == '.')
368 name++;
369 sym->idle = symbol__is_idle(name);
370 }
371
372 while (*p != NULL) {
373 parent = *p;
374 s = rb_entry(parent, struct symbol, rb_node);
375 if (ip < s->start)
376 p = &(*p)->rb_left;
377 else {
378 p = &(*p)->rb_right;
379 leftmost = false;
380 }
381 }
382 rb_link_node(&sym->rb_node, parent, p);
383 rb_insert_color_cached(&sym->rb_node, symbols, leftmost);
384 }
385
symbols__insert(struct rb_root_cached * symbols,struct symbol * sym)386 void symbols__insert(struct rb_root_cached *symbols, struct symbol *sym)
387 {
388 __symbols__insert(symbols, sym, false);
389 }
390
symbols__find(struct rb_root_cached * symbols,u64 ip)391 static struct symbol *symbols__find(struct rb_root_cached *symbols, u64 ip)
392 {
393 struct rb_node *n;
394
395 if (symbols == NULL)
396 return NULL;
397
398 n = symbols->rb_root.rb_node;
399
400 while (n) {
401 struct symbol *s = rb_entry(n, struct symbol, rb_node);
402
403 if (ip < s->start)
404 n = n->rb_left;
405 else if (ip > s->end || (ip == s->end && ip != s->start))
406 n = n->rb_right;
407 else
408 return s;
409 }
410
411 return NULL;
412 }
413
symbols__first(struct rb_root_cached * symbols)414 static struct symbol *symbols__first(struct rb_root_cached *symbols)
415 {
416 struct rb_node *n = rb_first_cached(symbols);
417
418 if (n)
419 return rb_entry(n, struct symbol, rb_node);
420
421 return NULL;
422 }
423
symbols__last(struct rb_root_cached * symbols)424 static struct symbol *symbols__last(struct rb_root_cached *symbols)
425 {
426 struct rb_node *n = rb_last(&symbols->rb_root);
427
428 if (n)
429 return rb_entry(n, struct symbol, rb_node);
430
431 return NULL;
432 }
433
symbols__next(struct symbol * sym)434 static struct symbol *symbols__next(struct symbol *sym)
435 {
436 struct rb_node *n = rb_next(&sym->rb_node);
437
438 if (n)
439 return rb_entry(n, struct symbol, rb_node);
440
441 return NULL;
442 }
443
symbols__sort_name_cmp(const void * vlhs,const void * vrhs)444 static int symbols__sort_name_cmp(const void *vlhs, const void *vrhs)
445 {
446 const struct symbol *lhs = *((const struct symbol **)vlhs);
447 const struct symbol *rhs = *((const struct symbol **)vrhs);
448
449 return strcmp(lhs->name, rhs->name);
450 }
451
symbols__sort_by_name(struct rb_root_cached * source,size_t * len)452 static struct symbol **symbols__sort_by_name(struct rb_root_cached *source, size_t *len)
453 {
454 struct rb_node *nd;
455 struct symbol **result;
456 size_t i = 0, size = 0;
457
458 for (nd = rb_first_cached(source); nd; nd = rb_next(nd))
459 size++;
460
461 result = malloc(sizeof(*result) * size);
462 if (!result)
463 return NULL;
464
465 for (nd = rb_first_cached(source); nd; nd = rb_next(nd)) {
466 struct symbol *pos = rb_entry(nd, struct symbol, rb_node);
467
468 result[i++] = pos;
469 }
470 qsort(result, size, sizeof(*result), symbols__sort_name_cmp);
471 *len = size;
472 return result;
473 }
474
symbol__match_symbol_name(const char * name,const char * str,enum symbol_tag_include includes)475 int symbol__match_symbol_name(const char *name, const char *str,
476 enum symbol_tag_include includes)
477 {
478 const char *versioning;
479
480 if (includes == SYMBOL_TAG_INCLUDE__DEFAULT_ONLY &&
481 (versioning = strstr(name, "@@"))) {
482 int len = strlen(str);
483
484 if (len < versioning - name)
485 len = versioning - name;
486
487 return arch__compare_symbol_names_n(name, str, len);
488 } else
489 return arch__compare_symbol_names(name, str);
490 }
491
symbols__find_by_name(struct symbol * symbols[],size_t symbols_len,const char * name,enum symbol_tag_include includes,size_t * found_idx)492 static struct symbol *symbols__find_by_name(struct symbol *symbols[],
493 size_t symbols_len,
494 const char *name,
495 enum symbol_tag_include includes,
496 size_t *found_idx)
497 {
498 size_t i, lower = 0, upper = symbols_len;
499 struct symbol *s = NULL;
500
501 if (found_idx)
502 *found_idx = SIZE_MAX;
503
504 if (!symbols_len)
505 return NULL;
506
507 while (lower < upper) {
508 int cmp;
509
510 i = (lower + upper) / 2;
511 cmp = symbol__match_symbol_name(symbols[i]->name, name, includes);
512
513 if (cmp > 0)
514 upper = i;
515 else if (cmp < 0)
516 lower = i + 1;
517 else {
518 if (found_idx)
519 *found_idx = i;
520 s = symbols[i];
521 break;
522 }
523 }
524 if (s && includes != SYMBOL_TAG_INCLUDE__DEFAULT_ONLY) {
525 /* return first symbol that has same name (if any) */
526 for (; i > 0; i--) {
527 struct symbol *tmp = symbols[i - 1];
528
529 if (!arch__compare_symbol_names(tmp->name, s->name)) {
530 if (found_idx)
531 *found_idx = i - 1;
532 s = tmp;
533 } else
534 break;
535 }
536 }
537 assert(!found_idx || !s || s == symbols[*found_idx]);
538 return s;
539 }
540
dso__reset_find_symbol_cache(struct dso * dso)541 void dso__reset_find_symbol_cache(struct dso *dso)
542 {
543 dso__set_last_find_result_addr(dso, 0);
544 dso__set_last_find_result_symbol(dso, NULL);
545 }
546
dso__insert_symbol(struct dso * dso,struct symbol * sym)547 void dso__insert_symbol(struct dso *dso, struct symbol *sym)
548 {
549 __symbols__insert(dso__symbols(dso), sym, dso__kernel(dso));
550
551 /* update the symbol cache if necessary */
552 if (dso__last_find_result_addr(dso) >= sym->start &&
553 (dso__last_find_result_addr(dso) < sym->end ||
554 sym->start == sym->end)) {
555 dso__set_last_find_result_symbol(dso, sym);
556 }
557 }
558
dso__delete_symbol(struct dso * dso,struct symbol * sym)559 void dso__delete_symbol(struct dso *dso, struct symbol *sym)
560 {
561 rb_erase_cached(&sym->rb_node, dso__symbols(dso));
562 symbol__delete(sym);
563 dso__reset_find_symbol_cache(dso);
564 }
565
dso__find_symbol(struct dso * dso,u64 addr)566 struct symbol *dso__find_symbol(struct dso *dso, u64 addr)
567 {
568 if (dso__last_find_result_addr(dso) != addr || dso__last_find_result_symbol(dso) == NULL) {
569 dso__set_last_find_result_addr(dso, addr);
570 dso__set_last_find_result_symbol(dso, symbols__find(dso__symbols(dso), addr));
571 }
572
573 return dso__last_find_result_symbol(dso);
574 }
575
dso__find_symbol_nocache(struct dso * dso,u64 addr)576 struct symbol *dso__find_symbol_nocache(struct dso *dso, u64 addr)
577 {
578 return symbols__find(dso__symbols(dso), addr);
579 }
580
dso__first_symbol(struct dso * dso)581 struct symbol *dso__first_symbol(struct dso *dso)
582 {
583 return symbols__first(dso__symbols(dso));
584 }
585
dso__last_symbol(struct dso * dso)586 struct symbol *dso__last_symbol(struct dso *dso)
587 {
588 return symbols__last(dso__symbols(dso));
589 }
590
dso__next_symbol(struct symbol * sym)591 struct symbol *dso__next_symbol(struct symbol *sym)
592 {
593 return symbols__next(sym);
594 }
595
dso__next_symbol_by_name(struct dso * dso,size_t * idx)596 struct symbol *dso__next_symbol_by_name(struct dso *dso, size_t *idx)
597 {
598 if (*idx + 1 >= dso__symbol_names_len(dso))
599 return NULL;
600
601 ++*idx;
602 return dso__symbol_names(dso)[*idx];
603 }
604
605 /*
606 * Returns first symbol that matched with @name.
607 */
dso__find_symbol_by_name(struct dso * dso,const char * name,size_t * idx)608 struct symbol *dso__find_symbol_by_name(struct dso *dso, const char *name, size_t *idx)
609 {
610 struct symbol *s = symbols__find_by_name(dso__symbol_names(dso),
611 dso__symbol_names_len(dso),
612 name, SYMBOL_TAG_INCLUDE__NONE, idx);
613 if (!s) {
614 s = symbols__find_by_name(dso__symbol_names(dso), dso__symbol_names_len(dso),
615 name, SYMBOL_TAG_INCLUDE__DEFAULT_ONLY, idx);
616 }
617 return s;
618 }
619
dso__sort_by_name(struct dso * dso)620 void dso__sort_by_name(struct dso *dso)
621 {
622 mutex_lock(dso__lock(dso));
623 if (!dso__sorted_by_name(dso)) {
624 size_t len;
625
626 dso__set_symbol_names(dso, symbols__sort_by_name(dso__symbols(dso), &len));
627 if (dso__symbol_names(dso)) {
628 dso__set_symbol_names_len(dso, len);
629 dso__set_sorted_by_name(dso);
630 }
631 }
632 mutex_unlock(dso__lock(dso));
633 }
634
635 /*
636 * While we find nice hex chars, build a long_val.
637 * Return number of chars processed.
638 */
hex2u64(const char * ptr,u64 * long_val)639 static int hex2u64(const char *ptr, u64 *long_val)
640 {
641 char *p;
642
643 *long_val = strtoull(ptr, &p, 16);
644
645 return p - ptr;
646 }
647
648
modules__parse(const char * filename,void * arg,int (* process_module)(void * arg,const char * name,u64 start,u64 size))649 int modules__parse(const char *filename, void *arg,
650 int (*process_module)(void *arg, const char *name,
651 u64 start, u64 size))
652 {
653 char *line = NULL;
654 size_t n;
655 FILE *file;
656 int err = 0;
657
658 file = fopen(filename, "r");
659 if (file == NULL)
660 return -1;
661
662 while (1) {
663 char name[PATH_MAX];
664 u64 start, size;
665 char *sep, *endptr;
666 ssize_t line_len;
667
668 line_len = getline(&line, &n, file);
669 if (line_len < 0) {
670 if (feof(file))
671 break;
672 err = -1;
673 goto out;
674 }
675
676 if (!line) {
677 err = -1;
678 goto out;
679 }
680
681 line[--line_len] = '\0'; /* \n */
682
683 sep = strrchr(line, 'x');
684 if (sep == NULL)
685 continue;
686
687 hex2u64(sep + 1, &start);
688
689 sep = strchr(line, ' ');
690 if (sep == NULL)
691 continue;
692
693 *sep = '\0';
694
695 scnprintf(name, sizeof(name), "[%s]", line);
696
697 size = strtoul(sep + 1, &endptr, 0);
698 if (*endptr != ' ' && *endptr != '\t')
699 continue;
700
701 err = process_module(arg, name, start, size);
702 if (err)
703 break;
704 }
705 out:
706 free(line);
707 fclose(file);
708 return err;
709 }
710
711 /*
712 * These are symbols in the kernel image, so make sure that
713 * sym is from a kernel DSO.
714 */
symbol__is_idle(const char * name)715 static bool symbol__is_idle(const char *name)
716 {
717 const char * const idle_symbols[] = {
718 "acpi_idle_do_entry",
719 "acpi_processor_ffh_cstate_enter",
720 "arch_cpu_idle",
721 "cpu_idle",
722 "cpu_startup_entry",
723 "idle_cpu",
724 "intel_idle",
725 "intel_idle_ibrs",
726 "default_idle",
727 "native_safe_halt",
728 "enter_idle",
729 "exit_idle",
730 "mwait_idle",
731 "mwait_idle_with_hints",
732 "mwait_idle_with_hints.constprop.0",
733 "poll_idle",
734 "ppc64_runlatch_off",
735 "pseries_dedicated_idle_sleep",
736 "psw_idle",
737 "psw_idle_exit",
738 NULL
739 };
740 int i;
741 static struct strlist *idle_symbols_list;
742
743 if (idle_symbols_list)
744 return strlist__has_entry(idle_symbols_list, name);
745
746 idle_symbols_list = strlist__new(NULL, NULL);
747
748 for (i = 0; idle_symbols[i]; i++)
749 strlist__add(idle_symbols_list, idle_symbols[i]);
750
751 return strlist__has_entry(idle_symbols_list, name);
752 }
753
map__process_kallsym_symbol(void * arg,const char * name,char type,u64 start)754 static int map__process_kallsym_symbol(void *arg, const char *name,
755 char type, u64 start)
756 {
757 struct symbol *sym;
758 struct dso *dso = arg;
759 struct rb_root_cached *root = dso__symbols(dso);
760
761 if (!symbol_type__filter(type))
762 return 0;
763
764 /* Ignore local symbols for ARM modules */
765 if (name[0] == '$')
766 return 0;
767
768 /*
769 * module symbols are not sorted so we add all
770 * symbols, setting length to 0, and rely on
771 * symbols__fixup_end() to fix it up.
772 */
773 sym = symbol__new(start, 0, kallsyms2elf_binding(type), kallsyms2elf_type(type), name);
774 if (sym == NULL)
775 return -ENOMEM;
776 /*
777 * We will pass the symbols to the filter later, in
778 * map__split_kallsyms, when we have split the maps per module
779 */
780 __symbols__insert(root, sym, !strchr(name, '['));
781
782 return 0;
783 }
784
785 /*
786 * Loads the function entries in /proc/kallsyms into kernel_map->dso,
787 * so that we can in the next step set the symbol ->end address and then
788 * call kernel_maps__split_kallsyms.
789 */
dso__load_all_kallsyms(struct dso * dso,const char * filename)790 static int dso__load_all_kallsyms(struct dso *dso, const char *filename)
791 {
792 return kallsyms__parse(filename, dso, map__process_kallsym_symbol);
793 }
794
maps__split_kallsyms_for_kcore(struct maps * kmaps,struct dso * dso)795 static int maps__split_kallsyms_for_kcore(struct maps *kmaps, struct dso *dso)
796 {
797 struct symbol *pos;
798 int count = 0;
799 struct rb_root_cached *root = dso__symbols(dso);
800 struct rb_root_cached old_root = *root;
801 struct rb_node *next = rb_first_cached(root);
802
803 if (!kmaps)
804 return -1;
805
806 *root = RB_ROOT_CACHED;
807
808 while (next) {
809 struct map *curr_map;
810 struct dso *curr_map_dso;
811 char *module;
812
813 pos = rb_entry(next, struct symbol, rb_node);
814 next = rb_next(&pos->rb_node);
815
816 rb_erase_cached(&pos->rb_node, &old_root);
817 RB_CLEAR_NODE(&pos->rb_node);
818 module = strchr(pos->name, '\t');
819 if (module)
820 *module = '\0';
821
822 curr_map = maps__find(kmaps, pos->start);
823
824 if (!curr_map) {
825 symbol__delete(pos);
826 continue;
827 }
828 curr_map_dso = map__dso(curr_map);
829 pos->start -= map__start(curr_map) - map__pgoff(curr_map);
830 if (pos->end > map__end(curr_map))
831 pos->end = map__end(curr_map);
832 if (pos->end)
833 pos->end -= map__start(curr_map) - map__pgoff(curr_map);
834 symbols__insert(dso__symbols(curr_map_dso), pos);
835 ++count;
836 map__put(curr_map);
837 }
838
839 /* Symbols have been adjusted */
840 dso__set_adjust_symbols(dso, true);
841
842 return count;
843 }
844
845 /*
846 * Split the symbols into maps, making sure there are no overlaps, i.e. the
847 * kernel range is broken in several maps, named [kernel].N, as we don't have
848 * the original ELF section names vmlinux have.
849 */
maps__split_kallsyms(struct maps * kmaps,struct dso * dso,u64 delta,struct map * initial_map)850 static int maps__split_kallsyms(struct maps *kmaps, struct dso *dso, u64 delta,
851 struct map *initial_map)
852 {
853 struct machine *machine;
854 struct map *curr_map = map__get(initial_map);
855 struct symbol *pos;
856 int count = 0, moved = 0;
857 struct rb_root_cached *root = dso__symbols(dso);
858 struct rb_node *next = rb_first_cached(root);
859 int kernel_range = 0;
860 bool x86_64;
861
862 if (!kmaps)
863 return -1;
864
865 machine = maps__machine(kmaps);
866
867 x86_64 = machine__is(machine, "x86_64");
868
869 while (next) {
870 char *module;
871
872 pos = rb_entry(next, struct symbol, rb_node);
873 next = rb_next(&pos->rb_node);
874
875 module = strchr(pos->name, '\t');
876 if (module) {
877 struct dso *curr_map_dso;
878
879 if (!symbol_conf.use_modules)
880 goto discard_symbol;
881
882 *module++ = '\0';
883 curr_map_dso = map__dso(curr_map);
884 if (strcmp(dso__short_name(curr_map_dso), module)) {
885 if (!RC_CHK_EQUAL(curr_map, initial_map) &&
886 dso__kernel(dso) == DSO_SPACE__KERNEL_GUEST &&
887 machine__is_default_guest(machine)) {
888 /*
889 * We assume all symbols of a module are
890 * continuous in * kallsyms, so curr_map
891 * points to a module and all its
892 * symbols are in its kmap. Mark it as
893 * loaded.
894 */
895 dso__set_loaded(curr_map_dso);
896 }
897
898 map__zput(curr_map);
899 curr_map = maps__find_by_name(kmaps, module);
900 if (curr_map == NULL) {
901 pr_debug("%s/proc/{kallsyms,modules} "
902 "inconsistency while looking "
903 "for \"%s\" module!\n",
904 machine->root_dir, module);
905 curr_map = map__get(initial_map);
906 goto discard_symbol;
907 }
908 curr_map_dso = map__dso(curr_map);
909 if (dso__loaded(curr_map_dso) &&
910 !machine__is_default_guest(machine))
911 goto discard_symbol;
912 }
913 /*
914 * So that we look just like we get from .ko files,
915 * i.e. not prelinked, relative to initial_map->start.
916 */
917 pos->start = map__map_ip(curr_map, pos->start);
918 pos->end = map__map_ip(curr_map, pos->end);
919 } else if (x86_64 && is_entry_trampoline(pos->name)) {
920 /*
921 * These symbols are not needed anymore since the
922 * trampoline maps refer to the text section and it's
923 * symbols instead. Avoid having to deal with
924 * relocations, and the assumption that the first symbol
925 * is the start of kernel text, by simply removing the
926 * symbols at this point.
927 */
928 goto discard_symbol;
929 } else if (!RC_CHK_EQUAL(curr_map, initial_map)) {
930 char dso_name[PATH_MAX];
931 struct dso *ndso;
932
933 if (delta) {
934 /* Kernel was relocated at boot time */
935 pos->start -= delta;
936 pos->end -= delta;
937 }
938
939 if (count == 0) {
940 map__zput(curr_map);
941 curr_map = map__get(initial_map);
942 goto add_symbol;
943 }
944
945 if (dso__kernel(dso) == DSO_SPACE__KERNEL_GUEST)
946 snprintf(dso_name, sizeof(dso_name),
947 "[guest.kernel].%d",
948 kernel_range++);
949 else
950 snprintf(dso_name, sizeof(dso_name),
951 "[kernel].%d",
952 kernel_range++);
953
954 ndso = dso__new(dso_name);
955 map__zput(curr_map);
956 if (ndso == NULL)
957 return -1;
958
959 dso__set_kernel(ndso, dso__kernel(dso));
960
961 curr_map = map__new2(pos->start, ndso);
962 if (curr_map == NULL) {
963 dso__put(ndso);
964 return -1;
965 }
966
967 map__set_mapping_type(curr_map, MAPPING_TYPE__IDENTITY);
968 if (maps__insert(kmaps, curr_map)) {
969 map__zput(curr_map);
970 dso__put(ndso);
971 return -1;
972 }
973 ++kernel_range;
974 } else if (delta) {
975 /* Kernel was relocated at boot time */
976 pos->start -= delta;
977 pos->end -= delta;
978 }
979 add_symbol:
980 if (!RC_CHK_EQUAL(curr_map, initial_map)) {
981 struct dso *curr_map_dso = map__dso(curr_map);
982
983 rb_erase_cached(&pos->rb_node, root);
984 symbols__insert(dso__symbols(curr_map_dso), pos);
985 ++moved;
986 } else
987 ++count;
988
989 continue;
990 discard_symbol:
991 rb_erase_cached(&pos->rb_node, root);
992 symbol__delete(pos);
993 }
994
995 if (!RC_CHK_EQUAL(curr_map, initial_map) &&
996 dso__kernel(dso) == DSO_SPACE__KERNEL_GUEST &&
997 machine__is_default_guest(maps__machine(kmaps))) {
998 dso__set_loaded(map__dso(curr_map));
999 }
1000 map__put(curr_map);
1001 return count + moved;
1002 }
1003
symbol__restricted_filename(const char * filename,const char * restricted_filename)1004 bool symbol__restricted_filename(const char *filename,
1005 const char *restricted_filename)
1006 {
1007 bool restricted = false;
1008
1009 if (symbol_conf.kptr_restrict) {
1010 char *r = realpath(filename, NULL);
1011
1012 if (r != NULL) {
1013 restricted = strcmp(r, restricted_filename) == 0;
1014 free(r);
1015 return restricted;
1016 }
1017 }
1018
1019 return restricted;
1020 }
1021
1022 struct module_info {
1023 struct rb_node rb_node;
1024 char *name;
1025 u64 start;
1026 };
1027
add_module(struct module_info * mi,struct rb_root * modules)1028 static void add_module(struct module_info *mi, struct rb_root *modules)
1029 {
1030 struct rb_node **p = &modules->rb_node;
1031 struct rb_node *parent = NULL;
1032 struct module_info *m;
1033
1034 while (*p != NULL) {
1035 parent = *p;
1036 m = rb_entry(parent, struct module_info, rb_node);
1037 if (strcmp(mi->name, m->name) < 0)
1038 p = &(*p)->rb_left;
1039 else
1040 p = &(*p)->rb_right;
1041 }
1042 rb_link_node(&mi->rb_node, parent, p);
1043 rb_insert_color(&mi->rb_node, modules);
1044 }
1045
delete_modules(struct rb_root * modules)1046 static void delete_modules(struct rb_root *modules)
1047 {
1048 struct module_info *mi;
1049 struct rb_node *next = rb_first(modules);
1050
1051 while (next) {
1052 mi = rb_entry(next, struct module_info, rb_node);
1053 next = rb_next(&mi->rb_node);
1054 rb_erase(&mi->rb_node, modules);
1055 zfree(&mi->name);
1056 free(mi);
1057 }
1058 }
1059
find_module(const char * name,struct rb_root * modules)1060 static struct module_info *find_module(const char *name,
1061 struct rb_root *modules)
1062 {
1063 struct rb_node *n = modules->rb_node;
1064
1065 while (n) {
1066 struct module_info *m;
1067 int cmp;
1068
1069 m = rb_entry(n, struct module_info, rb_node);
1070 cmp = strcmp(name, m->name);
1071 if (cmp < 0)
1072 n = n->rb_left;
1073 else if (cmp > 0)
1074 n = n->rb_right;
1075 else
1076 return m;
1077 }
1078
1079 return NULL;
1080 }
1081
__read_proc_modules(void * arg,const char * name,u64 start,u64 size __maybe_unused)1082 static int __read_proc_modules(void *arg, const char *name, u64 start,
1083 u64 size __maybe_unused)
1084 {
1085 struct rb_root *modules = arg;
1086 struct module_info *mi;
1087
1088 mi = zalloc(sizeof(struct module_info));
1089 if (!mi)
1090 return -ENOMEM;
1091
1092 mi->name = strdup(name);
1093 mi->start = start;
1094
1095 if (!mi->name) {
1096 free(mi);
1097 return -ENOMEM;
1098 }
1099
1100 add_module(mi, modules);
1101
1102 return 0;
1103 }
1104
read_proc_modules(const char * filename,struct rb_root * modules)1105 static int read_proc_modules(const char *filename, struct rb_root *modules)
1106 {
1107 if (symbol__restricted_filename(filename, "/proc/modules"))
1108 return -1;
1109
1110 if (modules__parse(filename, modules, __read_proc_modules)) {
1111 delete_modules(modules);
1112 return -1;
1113 }
1114
1115 return 0;
1116 }
1117
compare_proc_modules(const char * from,const char * to)1118 int compare_proc_modules(const char *from, const char *to)
1119 {
1120 struct rb_root from_modules = RB_ROOT;
1121 struct rb_root to_modules = RB_ROOT;
1122 struct rb_node *from_node, *to_node;
1123 struct module_info *from_m, *to_m;
1124 int ret = -1;
1125
1126 if (read_proc_modules(from, &from_modules))
1127 return -1;
1128
1129 if (read_proc_modules(to, &to_modules))
1130 goto out_delete_from;
1131
1132 from_node = rb_first(&from_modules);
1133 to_node = rb_first(&to_modules);
1134 while (from_node) {
1135 if (!to_node)
1136 break;
1137
1138 from_m = rb_entry(from_node, struct module_info, rb_node);
1139 to_m = rb_entry(to_node, struct module_info, rb_node);
1140
1141 if (from_m->start != to_m->start ||
1142 strcmp(from_m->name, to_m->name))
1143 break;
1144
1145 from_node = rb_next(from_node);
1146 to_node = rb_next(to_node);
1147 }
1148
1149 if (!from_node && !to_node)
1150 ret = 0;
1151
1152 delete_modules(&to_modules);
1153 out_delete_from:
1154 delete_modules(&from_modules);
1155
1156 return ret;
1157 }
1158
do_validate_kcore_modules_cb(struct map * old_map,void * data)1159 static int do_validate_kcore_modules_cb(struct map *old_map, void *data)
1160 {
1161 struct rb_root *modules = data;
1162 struct module_info *mi;
1163 struct dso *dso;
1164
1165 if (!__map__is_kmodule(old_map))
1166 return 0;
1167
1168 dso = map__dso(old_map);
1169 /* Module must be in memory at the same address */
1170 mi = find_module(dso__short_name(dso), modules);
1171 if (!mi || mi->start != map__start(old_map))
1172 return -EINVAL;
1173
1174 return 0;
1175 }
1176
do_validate_kcore_modules(const char * filename,struct maps * kmaps)1177 static int do_validate_kcore_modules(const char *filename, struct maps *kmaps)
1178 {
1179 struct rb_root modules = RB_ROOT;
1180 int err;
1181
1182 err = read_proc_modules(filename, &modules);
1183 if (err)
1184 return err;
1185
1186 err = maps__for_each_map(kmaps, do_validate_kcore_modules_cb, &modules);
1187
1188 delete_modules(&modules);
1189 return err;
1190 }
1191
1192 /*
1193 * If kallsyms is referenced by name then we look for filename in the same
1194 * directory.
1195 */
filename_from_kallsyms_filename(char * filename,const char * base_name,const char * kallsyms_filename)1196 static bool filename_from_kallsyms_filename(char *filename,
1197 const char *base_name,
1198 const char *kallsyms_filename)
1199 {
1200 char *name;
1201
1202 strcpy(filename, kallsyms_filename);
1203 name = strrchr(filename, '/');
1204 if (!name)
1205 return false;
1206
1207 name += 1;
1208
1209 if (!strcmp(name, "kallsyms")) {
1210 strcpy(name, base_name);
1211 return true;
1212 }
1213
1214 return false;
1215 }
1216
validate_kcore_modules(const char * kallsyms_filename,struct map * map)1217 static int validate_kcore_modules(const char *kallsyms_filename,
1218 struct map *map)
1219 {
1220 struct maps *kmaps = map__kmaps(map);
1221 char modules_filename[PATH_MAX];
1222
1223 if (!kmaps)
1224 return -EINVAL;
1225
1226 if (!filename_from_kallsyms_filename(modules_filename, "modules",
1227 kallsyms_filename))
1228 return -EINVAL;
1229
1230 if (do_validate_kcore_modules(modules_filename, kmaps))
1231 return -EINVAL;
1232
1233 return 0;
1234 }
1235
validate_kcore_addresses(const char * kallsyms_filename,struct map * map)1236 static int validate_kcore_addresses(const char *kallsyms_filename,
1237 struct map *map)
1238 {
1239 struct kmap *kmap = map__kmap(map);
1240
1241 if (!kmap)
1242 return -EINVAL;
1243
1244 if (kmap->ref_reloc_sym && kmap->ref_reloc_sym->name) {
1245 u64 start;
1246
1247 if (kallsyms__get_function_start(kallsyms_filename,
1248 kmap->ref_reloc_sym->name, &start))
1249 return -ENOENT;
1250 if (start != kmap->ref_reloc_sym->addr)
1251 return -EINVAL;
1252 }
1253
1254 return validate_kcore_modules(kallsyms_filename, map);
1255 }
1256
1257 struct kcore_mapfn_data {
1258 struct dso *dso;
1259 struct list_head maps;
1260 };
1261
kcore_mapfn(u64 start,u64 len,u64 pgoff,void * data)1262 static int kcore_mapfn(u64 start, u64 len, u64 pgoff, void *data)
1263 {
1264 struct kcore_mapfn_data *md = data;
1265 struct map_list_node *list_node = map_list_node__new();
1266
1267 if (!list_node)
1268 return -ENOMEM;
1269
1270 list_node->map = map__new2(start, md->dso);
1271 if (!list_node->map) {
1272 free(list_node);
1273 return -ENOMEM;
1274 }
1275
1276 map__set_end(list_node->map, map__start(list_node->map) + len);
1277 map__set_pgoff(list_node->map, pgoff);
1278
1279 list_add(&list_node->node, &md->maps);
1280
1281 return 0;
1282 }
1283
remove_old_maps(struct map * map,void * data)1284 static bool remove_old_maps(struct map *map, void *data)
1285 {
1286 const struct map *map_to_save = data;
1287
1288 /*
1289 * We need to preserve eBPF maps even if they are covered by kcore,
1290 * because we need to access eBPF dso for source data.
1291 */
1292 return !RC_CHK_EQUAL(map, map_to_save) && !__map__is_bpf_prog(map);
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 *map_ref, *replacement_map = NULL;
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 = maps__machine(kmaps);
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(map) & PROT_EXEC, kcore_mapfn, &md,
1336 &is_64_bit);
1337 if (err)
1338 goto out_err;
1339 dso__set_is_64_bit(dso, 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__remove_maps(kmaps, remove_old_maps, map);
1348 machine->trampolines_mapped = false;
1349
1350 /* Find the kernel map using the '_stext' symbol */
1351 if (!kallsyms__get_function_start(kallsyms_filename, "_stext", &stext)) {
1352 u64 replacement_size = 0;
1353 struct map_list_node *new_node;
1354
1355 list_for_each_entry(new_node, &md.maps, node) {
1356 struct map *new_map = new_node->map;
1357 u64 new_size = map__size(new_map);
1358
1359 if (!(stext >= map__start(new_map) && stext < map__end(new_map)))
1360 continue;
1361
1362 /*
1363 * On some architectures, ARM64 for example, the kernel
1364 * text can get allocated inside of the vmalloc segment.
1365 * Select the smallest matching segment, in case stext
1366 * falls within more than one in the list.
1367 */
1368 if (!replacement_map || new_size < replacement_size) {
1369 replacement_map = new_map;
1370 replacement_size = new_size;
1371 }
1372 }
1373 }
1374
1375 if (!replacement_map)
1376 replacement_map = list_entry(md.maps.next, struct map_list_node, node)->map;
1377
1378 /*
1379 * Update addresses of vmlinux map. Re-insert it to ensure maps are
1380 * correctly ordered. Do this before using maps__merge_in() for the
1381 * remaining maps so vmlinux gets split if necessary.
1382 */
1383 map_ref = map__get(map);
1384 maps__remove(kmaps, map_ref);
1385
1386 map__set_start(map_ref, map__start(replacement_map));
1387 map__set_end(map_ref, map__end(replacement_map));
1388 map__set_pgoff(map_ref, map__pgoff(replacement_map));
1389 map__set_mapping_type(map_ref, map__mapping_type(replacement_map));
1390
1391 err = maps__insert(kmaps, map_ref);
1392 map__put(map_ref);
1393 if (err)
1394 goto out_err;
1395
1396 /* Add new maps */
1397 while (!list_empty(&md.maps)) {
1398 struct map_list_node *new_node = list_entry(md.maps.next, struct map_list_node, node);
1399 struct map *new_map = new_node->map;
1400
1401 list_del_init(&new_node->node);
1402
1403 /* skip if replacement_map, already inserted above */
1404 if (!RC_CHK_EQUAL(new_map, replacement_map)) {
1405 /*
1406 * Merge kcore map into existing maps,
1407 * and ensure that current maps (eBPF)
1408 * stay intact.
1409 */
1410 if (maps__merge_in(kmaps, new_map)) {
1411 err = -EINVAL;
1412 goto out_err;
1413 }
1414 }
1415 free(new_node);
1416 }
1417
1418 if (machine__is(machine, "x86_64")) {
1419 u64 addr;
1420
1421 /*
1422 * If one of the corresponding symbols is there, assume the
1423 * entry trampoline maps are too.
1424 */
1425 if (!kallsyms__get_function_start(kallsyms_filename,
1426 ENTRY_TRAMPOLINE_NAME,
1427 &addr))
1428 machine->trampolines_mapped = true;
1429 }
1430
1431 /*
1432 * Set the data type and long name so that kcore can be read via
1433 * dso__data_read_addr().
1434 */
1435 if (dso__kernel(dso) == DSO_SPACE__KERNEL_GUEST)
1436 dso__set_binary_type(dso, DSO_BINARY_TYPE__GUEST_KCORE);
1437 else
1438 dso__set_binary_type(dso, DSO_BINARY_TYPE__KCORE);
1439 dso__set_long_name(dso, strdup(kcore_filename), true);
1440
1441 close(fd);
1442
1443 if (map__prot(map) & PROT_EXEC)
1444 pr_debug("Using %s for kernel object code\n", kcore_filename);
1445 else
1446 pr_debug("Using %s for kernel data\n", kcore_filename);
1447
1448 return 0;
1449
1450 out_err:
1451 while (!list_empty(&md.maps)) {
1452 struct map_list_node *list_node;
1453
1454 list_node = list_entry(md.maps.next, struct map_list_node, node);
1455 list_del_init(&list_node->node);
1456 map__zput(list_node->map);
1457 free(list_node);
1458 }
1459 close(fd);
1460 return err;
1461 }
1462
1463 /*
1464 * If the kernel is relocated at boot time, kallsyms won't match. Compute the
1465 * delta based on the relocation reference symbol.
1466 */
kallsyms__delta(struct kmap * kmap,const char * filename,u64 * delta)1467 static int kallsyms__delta(struct kmap *kmap, const char *filename, u64 *delta)
1468 {
1469 u64 addr;
1470
1471 if (!kmap->ref_reloc_sym || !kmap->ref_reloc_sym->name)
1472 return 0;
1473
1474 if (kallsyms__get_function_start(filename, kmap->ref_reloc_sym->name, &addr))
1475 return -1;
1476
1477 *delta = addr - kmap->ref_reloc_sym->addr;
1478 return 0;
1479 }
1480
__dso__load_kallsyms(struct dso * dso,const char * filename,struct map * map,bool no_kcore)1481 int __dso__load_kallsyms(struct dso *dso, const char *filename,
1482 struct map *map, bool no_kcore)
1483 {
1484 struct kmap *kmap = map__kmap(map);
1485 u64 delta = 0;
1486
1487 if (symbol__restricted_filename(filename, "/proc/kallsyms"))
1488 return -1;
1489
1490 if (!kmap || !kmap->kmaps)
1491 return -1;
1492
1493 if (dso__load_all_kallsyms(dso, filename) < 0)
1494 return -1;
1495
1496 if (kallsyms__delta(kmap, filename, &delta))
1497 return -1;
1498
1499 symbols__fixup_end(dso__symbols(dso), true);
1500 symbols__fixup_duplicate(dso__symbols(dso));
1501
1502 if (dso__kernel(dso) == DSO_SPACE__KERNEL_GUEST)
1503 dso__set_symtab_type(dso, DSO_BINARY_TYPE__GUEST_KALLSYMS);
1504 else
1505 dso__set_symtab_type(dso, DSO_BINARY_TYPE__KALLSYMS);
1506
1507 if (!no_kcore && !dso__load_kcore(dso, map, filename))
1508 return maps__split_kallsyms_for_kcore(kmap->kmaps, dso);
1509 else
1510 return maps__split_kallsyms(kmap->kmaps, dso, delta, map);
1511 }
1512
dso__load_kallsyms(struct dso * dso,const char * filename,struct map * map)1513 int dso__load_kallsyms(struct dso *dso, const char *filename,
1514 struct map *map)
1515 {
1516 return __dso__load_kallsyms(dso, filename, map, false);
1517 }
1518
dso__load_perf_map(const char * map_path,struct dso * dso)1519 static int dso__load_perf_map(const char *map_path, struct dso *dso)
1520 {
1521 char *line = NULL;
1522 size_t n;
1523 FILE *file;
1524 int nr_syms = 0;
1525
1526 file = fopen(map_path, "r");
1527 if (file == NULL)
1528 goto out_failure;
1529
1530 while (!feof(file)) {
1531 u64 start, size;
1532 struct symbol *sym;
1533 int line_len, len;
1534
1535 line_len = getline(&line, &n, file);
1536 if (line_len < 0)
1537 break;
1538
1539 if (!line)
1540 goto out_failure;
1541
1542 line[--line_len] = '\0'; /* \n */
1543
1544 len = hex2u64(line, &start);
1545
1546 len++;
1547 if (len + 2 >= line_len)
1548 continue;
1549
1550 len += hex2u64(line + len, &size);
1551
1552 len++;
1553 if (len + 2 >= line_len)
1554 continue;
1555
1556 sym = symbol__new(start, size, STB_GLOBAL, STT_FUNC, line + len);
1557
1558 if (sym == NULL)
1559 goto out_delete_line;
1560
1561 symbols__insert(dso__symbols(dso), sym);
1562 nr_syms++;
1563 }
1564
1565 free(line);
1566 fclose(file);
1567
1568 return nr_syms;
1569
1570 out_delete_line:
1571 free(line);
1572 out_failure:
1573 return -1;
1574 }
1575
1576 #ifdef HAVE_LIBBFD_SUPPORT
1577 #define PACKAGE 'perf'
1578 #include <bfd.h>
1579
bfd_symbols__cmpvalue(const void * a,const void * b)1580 static int bfd_symbols__cmpvalue(const void *a, const void *b)
1581 {
1582 const asymbol *as = *(const asymbol **)a, *bs = *(const asymbol **)b;
1583
1584 if (bfd_asymbol_value(as) != bfd_asymbol_value(bs))
1585 return bfd_asymbol_value(as) - bfd_asymbol_value(bs);
1586
1587 return bfd_asymbol_name(as)[0] - bfd_asymbol_name(bs)[0];
1588 }
1589
bfd2elf_binding(asymbol * symbol)1590 static int bfd2elf_binding(asymbol *symbol)
1591 {
1592 if (symbol->flags & BSF_WEAK)
1593 return STB_WEAK;
1594 if (symbol->flags & BSF_GLOBAL)
1595 return STB_GLOBAL;
1596 if (symbol->flags & BSF_LOCAL)
1597 return STB_LOCAL;
1598 return -1;
1599 }
1600
dso__load_bfd_symbols(struct dso * dso,const char * debugfile)1601 int dso__load_bfd_symbols(struct dso *dso, const char *debugfile)
1602 {
1603 int err = -1;
1604 long symbols_size, symbols_count, i;
1605 asection *section;
1606 asymbol **symbols, *sym;
1607 struct symbol *symbol;
1608 bfd *abfd;
1609 u64 start, len;
1610
1611 abfd = bfd_openr(debugfile, NULL);
1612 if (!abfd)
1613 return -1;
1614
1615 if (!bfd_check_format(abfd, bfd_object)) {
1616 pr_debug2("%s: cannot read %s bfd file.\n", __func__,
1617 dso__long_name(dso));
1618 goto out_close;
1619 }
1620
1621 if (bfd_get_flavour(abfd) == bfd_target_elf_flavour)
1622 goto out_close;
1623
1624 symbols_size = bfd_get_symtab_upper_bound(abfd);
1625 if (symbols_size == 0) {
1626 bfd_close(abfd);
1627 return 0;
1628 }
1629
1630 if (symbols_size < 0)
1631 goto out_close;
1632
1633 symbols = malloc(symbols_size);
1634 if (!symbols)
1635 goto out_close;
1636
1637 symbols_count = bfd_canonicalize_symtab(abfd, symbols);
1638 if (symbols_count < 0)
1639 goto out_free;
1640
1641 section = bfd_get_section_by_name(abfd, ".text");
1642 if (section) {
1643 for (i = 0; i < symbols_count; ++i) {
1644 if (!strcmp(bfd_asymbol_name(symbols[i]), "__ImageBase") ||
1645 !strcmp(bfd_asymbol_name(symbols[i]), "__image_base__"))
1646 break;
1647 }
1648 if (i < symbols_count) {
1649 /* PE symbols can only have 4 bytes, so use .text high bits */
1650 u64 text_offset = (section->vma - (u32)section->vma)
1651 + (u32)bfd_asymbol_value(symbols[i]);
1652 dso__set_text_offset(dso, text_offset);
1653 dso__set_text_end(dso, (section->vma - text_offset) + section->size);
1654 } else {
1655 dso__set_text_offset(dso, section->vma - section->filepos);
1656 dso__set_text_end(dso, section->filepos + section->size);
1657 }
1658 }
1659
1660 qsort(symbols, symbols_count, sizeof(asymbol *), bfd_symbols__cmpvalue);
1661
1662 #ifdef bfd_get_section
1663 #define bfd_asymbol_section bfd_get_section
1664 #endif
1665 for (i = 0; i < symbols_count; ++i) {
1666 sym = symbols[i];
1667 section = bfd_asymbol_section(sym);
1668 if (bfd2elf_binding(sym) < 0)
1669 continue;
1670
1671 while (i + 1 < symbols_count &&
1672 bfd_asymbol_section(symbols[i + 1]) == section &&
1673 bfd2elf_binding(symbols[i + 1]) < 0)
1674 i++;
1675
1676 if (i + 1 < symbols_count &&
1677 bfd_asymbol_section(symbols[i + 1]) == section)
1678 len = symbols[i + 1]->value - sym->value;
1679 else
1680 len = section->size - sym->value;
1681
1682 start = bfd_asymbol_value(sym) - dso__text_offset(dso);
1683 symbol = symbol__new(start, len, bfd2elf_binding(sym), STT_FUNC,
1684 bfd_asymbol_name(sym));
1685 if (!symbol)
1686 goto out_free;
1687
1688 symbols__insert(dso__symbols(dso), symbol);
1689 }
1690 #ifdef bfd_get_section
1691 #undef bfd_asymbol_section
1692 #endif
1693
1694 symbols__fixup_end(dso__symbols(dso), false);
1695 symbols__fixup_duplicate(dso__symbols(dso));
1696 dso__set_adjust_symbols(dso, true);
1697
1698 err = 0;
1699 out_free:
1700 free(symbols);
1701 out_close:
1702 bfd_close(abfd);
1703 return err;
1704 }
1705 #endif
1706
dso__is_compatible_symtab_type(struct dso * dso,bool kmod,enum dso_binary_type type)1707 static bool dso__is_compatible_symtab_type(struct dso *dso, bool kmod,
1708 enum dso_binary_type type)
1709 {
1710 switch (type) {
1711 case DSO_BINARY_TYPE__JAVA_JIT:
1712 case DSO_BINARY_TYPE__DEBUGLINK:
1713 case DSO_BINARY_TYPE__SYSTEM_PATH_DSO:
1714 case DSO_BINARY_TYPE__FEDORA_DEBUGINFO:
1715 case DSO_BINARY_TYPE__UBUNTU_DEBUGINFO:
1716 case DSO_BINARY_TYPE__MIXEDUP_UBUNTU_DEBUGINFO:
1717 case DSO_BINARY_TYPE__BUILDID_DEBUGINFO:
1718 case DSO_BINARY_TYPE__OPENEMBEDDED_DEBUGINFO:
1719 return !kmod && dso__kernel(dso) == DSO_SPACE__USER;
1720
1721 case DSO_BINARY_TYPE__KALLSYMS:
1722 case DSO_BINARY_TYPE__VMLINUX:
1723 case DSO_BINARY_TYPE__KCORE:
1724 return dso__kernel(dso) == DSO_SPACE__KERNEL;
1725
1726 case DSO_BINARY_TYPE__GUEST_KALLSYMS:
1727 case DSO_BINARY_TYPE__GUEST_VMLINUX:
1728 case DSO_BINARY_TYPE__GUEST_KCORE:
1729 return dso__kernel(dso) == DSO_SPACE__KERNEL_GUEST;
1730
1731 case DSO_BINARY_TYPE__GUEST_KMODULE:
1732 case DSO_BINARY_TYPE__GUEST_KMODULE_COMP:
1733 case DSO_BINARY_TYPE__SYSTEM_PATH_KMODULE:
1734 case DSO_BINARY_TYPE__SYSTEM_PATH_KMODULE_COMP:
1735 /*
1736 * kernel modules know their symtab type - it's set when
1737 * creating a module dso in machine__addnew_module_map().
1738 */
1739 return kmod && dso__symtab_type(dso) == type;
1740
1741 case DSO_BINARY_TYPE__BUILD_ID_CACHE:
1742 case DSO_BINARY_TYPE__BUILD_ID_CACHE_DEBUGINFO:
1743 return true;
1744
1745 case DSO_BINARY_TYPE__BPF_PROG_INFO:
1746 case DSO_BINARY_TYPE__BPF_IMAGE:
1747 case DSO_BINARY_TYPE__OOL:
1748 case DSO_BINARY_TYPE__NOT_FOUND:
1749 default:
1750 return false;
1751 }
1752 }
1753
1754 /* Checks for the existence of the perf-<pid>.map file in two different
1755 * locations. First, if the process is a separate mount namespace, check in
1756 * that namespace using the pid of the innermost pid namespace. If's not in a
1757 * namespace, or the file can't be found there, try in the mount namespace of
1758 * the tracing process using our view of its pid.
1759 */
dso__find_perf_map(char * filebuf,size_t bufsz,struct nsinfo ** nsip)1760 static int dso__find_perf_map(char *filebuf, size_t bufsz,
1761 struct nsinfo **nsip)
1762 {
1763 struct nscookie nsc;
1764 struct nsinfo *nsi;
1765 struct nsinfo *nnsi;
1766 int rc = -1;
1767
1768 nsi = *nsip;
1769
1770 if (nsinfo__need_setns(nsi)) {
1771 snprintf(filebuf, bufsz, "/tmp/perf-%d.map", nsinfo__nstgid(nsi));
1772 nsinfo__mountns_enter(nsi, &nsc);
1773 rc = access(filebuf, R_OK);
1774 nsinfo__mountns_exit(&nsc);
1775 if (rc == 0)
1776 return rc;
1777 }
1778
1779 nnsi = nsinfo__copy(nsi);
1780 if (nnsi) {
1781 nsinfo__put(nsi);
1782
1783 nsinfo__clear_need_setns(nnsi);
1784 snprintf(filebuf, bufsz, "/tmp/perf-%d.map", nsinfo__tgid(nnsi));
1785 *nsip = nnsi;
1786 rc = 0;
1787 }
1788
1789 return rc;
1790 }
1791
dso__load(struct dso * dso,struct map * map)1792 int dso__load(struct dso *dso, struct map *map)
1793 {
1794 char *name;
1795 int ret = -1;
1796 u_int i;
1797 struct machine *machine = NULL;
1798 char *root_dir = (char *) "";
1799 int ss_pos = 0;
1800 struct symsrc ss_[2];
1801 struct symsrc *syms_ss = NULL, *runtime_ss = NULL;
1802 bool kmod;
1803 bool perfmap;
1804 struct build_id bid;
1805 struct nscookie nsc;
1806 char newmapname[PATH_MAX];
1807 const char *map_path = dso__long_name(dso);
1808
1809 mutex_lock(dso__lock(dso));
1810 perfmap = is_perf_pid_map_name(map_path);
1811
1812 if (perfmap) {
1813 if (dso__nsinfo(dso) &&
1814 (dso__find_perf_map(newmapname, sizeof(newmapname),
1815 dso__nsinfo_ptr(dso)) == 0)) {
1816 map_path = newmapname;
1817 }
1818 }
1819
1820 nsinfo__mountns_enter(dso__nsinfo(dso), &nsc);
1821
1822 /* check again under the dso->lock */
1823 if (dso__loaded(dso)) {
1824 ret = 1;
1825 goto out;
1826 }
1827
1828 kmod = dso__is_kmod(dso);
1829
1830 if (dso__kernel(dso) && !kmod) {
1831 if (dso__kernel(dso) == DSO_SPACE__KERNEL)
1832 ret = dso__load_kernel_sym(dso, map);
1833 else if (dso__kernel(dso) == DSO_SPACE__KERNEL_GUEST)
1834 ret = dso__load_guest_kernel_sym(dso, map);
1835
1836 machine = maps__machine(map__kmaps(map));
1837 if (machine__is(machine, "x86_64"))
1838 machine__map_x86_64_entry_trampolines(machine, dso);
1839 goto out;
1840 }
1841
1842 dso__set_adjust_symbols(dso, false);
1843
1844 if (perfmap) {
1845 ret = dso__load_perf_map(map_path, dso);
1846 dso__set_symtab_type(dso, ret > 0
1847 ? DSO_BINARY_TYPE__JAVA_JIT
1848 : DSO_BINARY_TYPE__NOT_FOUND);
1849 goto out;
1850 }
1851
1852 if (machine)
1853 root_dir = machine->root_dir;
1854
1855 name = malloc(PATH_MAX);
1856 if (!name)
1857 goto out;
1858
1859 /*
1860 * Read the build id if possible. This is required for
1861 * DSO_BINARY_TYPE__BUILDID_DEBUGINFO to work
1862 */
1863 if (!dso__has_build_id(dso) &&
1864 is_regular_file(dso__long_name(dso))) {
1865 __symbol__join_symfs(name, PATH_MAX, dso__long_name(dso));
1866 if (filename__read_build_id(name, &bid) > 0)
1867 dso__set_build_id(dso, &bid);
1868 }
1869
1870 /*
1871 * Iterate over candidate debug images.
1872 * Keep track of "interesting" ones (those which have a symtab, dynsym,
1873 * and/or opd section) for processing.
1874 */
1875 for (i = 0; i < DSO_BINARY_TYPE__SYMTAB_CNT; i++) {
1876 struct symsrc *ss = &ss_[ss_pos];
1877 bool next_slot = false;
1878 bool is_reg;
1879 bool nsexit;
1880 int bfdrc = -1;
1881 int sirc = -1;
1882
1883 enum dso_binary_type symtab_type = binary_type_symtab[i];
1884
1885 nsexit = (symtab_type == DSO_BINARY_TYPE__BUILD_ID_CACHE ||
1886 symtab_type == DSO_BINARY_TYPE__BUILD_ID_CACHE_DEBUGINFO);
1887
1888 if (!dso__is_compatible_symtab_type(dso, kmod, symtab_type))
1889 continue;
1890
1891 if (dso__read_binary_type_filename(dso, symtab_type,
1892 root_dir, name, PATH_MAX))
1893 continue;
1894
1895 if (nsexit)
1896 nsinfo__mountns_exit(&nsc);
1897
1898 is_reg = is_regular_file(name);
1899 if (!is_reg && errno == ENOENT && dso__nsinfo(dso)) {
1900 char *new_name = dso__filename_with_chroot(dso, name);
1901 if (new_name) {
1902 is_reg = is_regular_file(new_name);
1903 strlcpy(name, new_name, PATH_MAX);
1904 free(new_name);
1905 }
1906 }
1907
1908 #ifdef HAVE_LIBBFD_SUPPORT
1909 if (is_reg)
1910 bfdrc = dso__load_bfd_symbols(dso, name);
1911 #endif
1912 if (is_reg && bfdrc < 0)
1913 sirc = symsrc__init(ss, dso, name, symtab_type);
1914
1915 if (nsexit)
1916 nsinfo__mountns_enter(dso__nsinfo(dso), &nsc);
1917
1918 if (bfdrc == 0) {
1919 ret = 0;
1920 break;
1921 }
1922
1923 if (!is_reg || sirc < 0)
1924 continue;
1925
1926 if (!syms_ss && symsrc__has_symtab(ss)) {
1927 syms_ss = ss;
1928 next_slot = true;
1929 if (!dso__symsrc_filename(dso))
1930 dso__set_symsrc_filename(dso, strdup(name));
1931 }
1932
1933 if (!runtime_ss && symsrc__possibly_runtime(ss)) {
1934 runtime_ss = ss;
1935 next_slot = true;
1936 }
1937
1938 if (next_slot) {
1939 ss_pos++;
1940
1941 if (dso__binary_type(dso) == DSO_BINARY_TYPE__NOT_FOUND)
1942 dso__set_binary_type(dso, symtab_type);
1943
1944 if (syms_ss && runtime_ss)
1945 break;
1946 } else {
1947 symsrc__destroy(ss);
1948 }
1949
1950 }
1951
1952 if (!runtime_ss && !syms_ss)
1953 goto out_free;
1954
1955 if (runtime_ss && !syms_ss) {
1956 syms_ss = runtime_ss;
1957 }
1958
1959 /* We'll have to hope for the best */
1960 if (!runtime_ss && syms_ss)
1961 runtime_ss = syms_ss;
1962
1963 if (syms_ss)
1964 ret = dso__load_sym(dso, map, syms_ss, runtime_ss, kmod);
1965 else
1966 ret = -1;
1967
1968 if (ret > 0) {
1969 int nr_plt;
1970
1971 nr_plt = dso__synthesize_plt_symbols(dso, runtime_ss);
1972 if (nr_plt > 0)
1973 ret += nr_plt;
1974 }
1975
1976 for (; ss_pos > 0; ss_pos--)
1977 symsrc__destroy(&ss_[ss_pos - 1]);
1978 out_free:
1979 free(name);
1980 if (ret < 0 && strstr(dso__name(dso), " (deleted)") != NULL)
1981 ret = 0;
1982 out:
1983 dso__set_loaded(dso);
1984 mutex_unlock(dso__lock(dso));
1985 nsinfo__mountns_exit(&nsc);
1986
1987 return ret;
1988 }
1989
1990 /*
1991 * Always takes ownership of vmlinux when vmlinux_allocated == true, even if
1992 * it returns an error.
1993 */
dso__load_vmlinux(struct dso * dso,struct map * map,const char * vmlinux,bool vmlinux_allocated)1994 int dso__load_vmlinux(struct dso *dso, struct map *map,
1995 const char *vmlinux, bool vmlinux_allocated)
1996 {
1997 int err = -1;
1998 struct symsrc ss;
1999 char symfs_vmlinux[PATH_MAX];
2000 enum dso_binary_type symtab_type;
2001
2002 if (vmlinux[0] == '/')
2003 snprintf(symfs_vmlinux, sizeof(symfs_vmlinux), "%s", vmlinux);
2004 else
2005 symbol__join_symfs(symfs_vmlinux, vmlinux);
2006
2007 if (dso__kernel(dso) == DSO_SPACE__KERNEL_GUEST)
2008 symtab_type = DSO_BINARY_TYPE__GUEST_VMLINUX;
2009 else
2010 symtab_type = DSO_BINARY_TYPE__VMLINUX;
2011
2012 if (symsrc__init(&ss, dso, symfs_vmlinux, symtab_type)) {
2013 if (vmlinux_allocated)
2014 free((char *) vmlinux);
2015 return -1;
2016 }
2017
2018 /*
2019 * dso__load_sym() may copy 'dso' which will result in the copies having
2020 * an incorrect long name unless we set it here first.
2021 */
2022 dso__set_long_name(dso, vmlinux, vmlinux_allocated);
2023 if (dso__kernel(dso) == DSO_SPACE__KERNEL_GUEST)
2024 dso__set_binary_type(dso, DSO_BINARY_TYPE__GUEST_VMLINUX);
2025 else
2026 dso__set_binary_type(dso, DSO_BINARY_TYPE__VMLINUX);
2027
2028 err = dso__load_sym(dso, map, &ss, &ss, 0);
2029 symsrc__destroy(&ss);
2030
2031 if (err > 0) {
2032 dso__set_loaded(dso);
2033 pr_debug("Using %s for symbols\n", symfs_vmlinux);
2034 }
2035
2036 return err;
2037 }
2038
dso__load_vmlinux_path(struct dso * dso,struct map * map)2039 int dso__load_vmlinux_path(struct dso *dso, struct map *map)
2040 {
2041 int i, err = 0;
2042 char *filename = NULL;
2043
2044 pr_debug("Looking at the vmlinux_path (%d entries long)\n",
2045 vmlinux_path__nr_entries + 1);
2046
2047 for (i = 0; i < vmlinux_path__nr_entries; ++i) {
2048 err = dso__load_vmlinux(dso, map, vmlinux_path[i], false);
2049 if (err > 0)
2050 goto out;
2051 }
2052
2053 if (!symbol_conf.ignore_vmlinux_buildid)
2054 filename = dso__build_id_filename(dso, NULL, 0, false);
2055 if (filename != NULL) {
2056 err = dso__load_vmlinux(dso, map, filename, true);
2057 if (err > 0)
2058 goto out;
2059 }
2060 out:
2061 return err;
2062 }
2063
visible_dir_filter(const char * name,struct dirent * d)2064 static bool visible_dir_filter(const char *name, struct dirent *d)
2065 {
2066 if (d->d_type != DT_DIR)
2067 return false;
2068 return lsdir_no_dot_filter(name, d);
2069 }
2070
find_matching_kcore(struct map * map,char * dir,size_t dir_sz)2071 static int find_matching_kcore(struct map *map, char *dir, size_t dir_sz)
2072 {
2073 char kallsyms_filename[PATH_MAX];
2074 int ret = -1;
2075 struct strlist *dirs;
2076 struct str_node *nd;
2077
2078 dirs = lsdir(dir, visible_dir_filter);
2079 if (!dirs)
2080 return -1;
2081
2082 strlist__for_each_entry(nd, dirs) {
2083 scnprintf(kallsyms_filename, sizeof(kallsyms_filename),
2084 "%s/%s/kallsyms", dir, nd->s);
2085 if (!validate_kcore_addresses(kallsyms_filename, map)) {
2086 strlcpy(dir, kallsyms_filename, dir_sz);
2087 ret = 0;
2088 break;
2089 }
2090 }
2091
2092 strlist__delete(dirs);
2093
2094 return ret;
2095 }
2096
2097 /*
2098 * Use open(O_RDONLY) to check readability directly instead of access(R_OK)
2099 * since access(R_OK) only checks with real UID/GID but open() use effective
2100 * UID/GID and actual capabilities (e.g. /proc/kcore requires CAP_SYS_RAWIO).
2101 */
filename__readable(const char * file)2102 static bool filename__readable(const char *file)
2103 {
2104 int fd = open(file, O_RDONLY);
2105 if (fd < 0)
2106 return false;
2107 close(fd);
2108 return true;
2109 }
2110
dso__find_kallsyms(struct dso * dso,struct map * map)2111 static char *dso__find_kallsyms(struct dso *dso, struct map *map)
2112 {
2113 struct build_id bid;
2114 char sbuild_id[SBUILD_ID_SIZE];
2115 bool is_host = false;
2116 char path[PATH_MAX];
2117
2118 if (!dso__has_build_id(dso)) {
2119 /*
2120 * Last resort, if we don't have a build-id and couldn't find
2121 * any vmlinux file, try the running kernel kallsyms table.
2122 */
2123 goto proc_kallsyms;
2124 }
2125
2126 if (sysfs__read_build_id("/sys/kernel/notes", &bid) == 0)
2127 is_host = dso__build_id_equal(dso, &bid);
2128
2129 /* Try a fast path for /proc/kallsyms if possible */
2130 if (is_host) {
2131 /*
2132 * Do not check the build-id cache, unless we know we cannot use
2133 * /proc/kcore or module maps don't match to /proc/kallsyms.
2134 * To check readability of /proc/kcore, do not use access(R_OK)
2135 * since /proc/kcore requires CAP_SYS_RAWIO to read and access
2136 * can't check it.
2137 */
2138 if (filename__readable("/proc/kcore") &&
2139 !validate_kcore_addresses("/proc/kallsyms", map))
2140 goto proc_kallsyms;
2141 }
2142
2143 build_id__sprintf(dso__bid(dso), sbuild_id);
2144
2145 /* Find kallsyms in build-id cache with kcore */
2146 scnprintf(path, sizeof(path), "%s/%s/%s",
2147 buildid_dir, DSO__NAME_KCORE, sbuild_id);
2148
2149 if (!find_matching_kcore(map, path, sizeof(path)))
2150 return strdup(path);
2151
2152 /* Use current /proc/kallsyms if possible */
2153 if (is_host) {
2154 proc_kallsyms:
2155 return strdup("/proc/kallsyms");
2156 }
2157
2158 /* Finally, find a cache of kallsyms */
2159 if (!build_id_cache__kallsyms_path(sbuild_id, path, sizeof(path))) {
2160 pr_err("No kallsyms or vmlinux with build-id %s was found\n",
2161 sbuild_id);
2162 return NULL;
2163 }
2164
2165 return strdup(path);
2166 }
2167
dso__load_kernel_sym(struct dso * dso,struct map * map)2168 static int dso__load_kernel_sym(struct dso *dso, struct map *map)
2169 {
2170 int err;
2171 const char *kallsyms_filename = NULL;
2172 char *kallsyms_allocated_filename = NULL;
2173 char *filename = NULL;
2174
2175 /*
2176 * Step 1: if the user specified a kallsyms or vmlinux filename, use
2177 * it and only it, reporting errors to the user if it cannot be used.
2178 *
2179 * For instance, try to analyse an ARM perf.data file _without_ a
2180 * build-id, or if the user specifies the wrong path to the right
2181 * vmlinux file, obviously we can't fallback to another vmlinux (a
2182 * x86_86 one, on the machine where analysis is being performed, say),
2183 * or worse, /proc/kallsyms.
2184 *
2185 * If the specified file _has_ a build-id and there is a build-id
2186 * section in the perf.data file, we will still do the expected
2187 * validation in dso__load_vmlinux and will bail out if they don't
2188 * match.
2189 */
2190 if (symbol_conf.kallsyms_name != NULL) {
2191 kallsyms_filename = symbol_conf.kallsyms_name;
2192 goto do_kallsyms;
2193 }
2194
2195 if (!symbol_conf.ignore_vmlinux && symbol_conf.vmlinux_name != NULL) {
2196 return dso__load_vmlinux(dso, map, symbol_conf.vmlinux_name, false);
2197 }
2198
2199 /*
2200 * Before checking on common vmlinux locations, check if it's
2201 * stored as standard build id binary (not kallsyms) under
2202 * .debug cache.
2203 */
2204 if (!symbol_conf.ignore_vmlinux_buildid)
2205 filename = __dso__build_id_filename(dso, NULL, 0, false, false);
2206 if (filename != NULL) {
2207 err = dso__load_vmlinux(dso, map, filename, true);
2208 if (err > 0)
2209 return err;
2210 }
2211
2212 if (!symbol_conf.ignore_vmlinux && vmlinux_path != NULL) {
2213 err = dso__load_vmlinux_path(dso, map);
2214 if (err > 0)
2215 return err;
2216 }
2217
2218 /* do not try local files if a symfs was given */
2219 if (symbol_conf.symfs[0] != 0)
2220 return -1;
2221
2222 kallsyms_allocated_filename = dso__find_kallsyms(dso, map);
2223 if (!kallsyms_allocated_filename)
2224 return -1;
2225
2226 kallsyms_filename = kallsyms_allocated_filename;
2227
2228 do_kallsyms:
2229 err = dso__load_kallsyms(dso, kallsyms_filename, map);
2230 if (err > 0)
2231 pr_debug("Using %s for symbols\n", kallsyms_filename);
2232 free(kallsyms_allocated_filename);
2233
2234 if (err > 0 && !dso__is_kcore(dso)) {
2235 dso__set_binary_type(dso, DSO_BINARY_TYPE__KALLSYMS);
2236 dso__set_long_name(dso, DSO__NAME_KALLSYMS, false);
2237 map__fixup_start(map);
2238 map__fixup_end(map);
2239 }
2240
2241 return err;
2242 }
2243
dso__load_guest_kernel_sym(struct dso * dso,struct map * map)2244 static int dso__load_guest_kernel_sym(struct dso *dso, struct map *map)
2245 {
2246 int err;
2247 const char *kallsyms_filename;
2248 struct machine *machine = maps__machine(map__kmaps(map));
2249 char path[PATH_MAX];
2250
2251 if (machine->kallsyms_filename) {
2252 kallsyms_filename = machine->kallsyms_filename;
2253 } else if (machine__is_default_guest(machine)) {
2254 /*
2255 * if the user specified a vmlinux filename, use it and only
2256 * it, reporting errors to the user if it cannot be used.
2257 * Or use file guest_kallsyms inputted by user on commandline
2258 */
2259 if (symbol_conf.default_guest_vmlinux_name != NULL) {
2260 err = dso__load_vmlinux(dso, map,
2261 symbol_conf.default_guest_vmlinux_name,
2262 false);
2263 return err;
2264 }
2265
2266 kallsyms_filename = symbol_conf.default_guest_kallsyms;
2267 if (!kallsyms_filename)
2268 return -1;
2269 } else {
2270 sprintf(path, "%s/proc/kallsyms", machine->root_dir);
2271 kallsyms_filename = path;
2272 }
2273
2274 err = dso__load_kallsyms(dso, kallsyms_filename, map);
2275 if (err > 0)
2276 pr_debug("Using %s for symbols\n", kallsyms_filename);
2277 if (err > 0 && !dso__is_kcore(dso)) {
2278 dso__set_binary_type(dso, DSO_BINARY_TYPE__GUEST_KALLSYMS);
2279 dso__set_long_name(dso, machine->mmap_name, false);
2280 map__fixup_start(map);
2281 map__fixup_end(map);
2282 }
2283
2284 return err;
2285 }
2286
vmlinux_path__exit(void)2287 static void vmlinux_path__exit(void)
2288 {
2289 while (--vmlinux_path__nr_entries >= 0)
2290 zfree(&vmlinux_path[vmlinux_path__nr_entries]);
2291 vmlinux_path__nr_entries = 0;
2292
2293 zfree(&vmlinux_path);
2294 }
2295
2296 static const char * const vmlinux_paths[] = {
2297 "vmlinux",
2298 "/boot/vmlinux"
2299 };
2300
2301 static const char * const vmlinux_paths_upd[] = {
2302 "/boot/vmlinux-%s",
2303 "/usr/lib/debug/boot/vmlinux-%s",
2304 "/lib/modules/%s/build/vmlinux",
2305 "/usr/lib/debug/lib/modules/%s/vmlinux",
2306 "/usr/lib/debug/boot/vmlinux-%s.debug"
2307 };
2308
vmlinux_path__add(const char * new_entry)2309 static int vmlinux_path__add(const char *new_entry)
2310 {
2311 vmlinux_path[vmlinux_path__nr_entries] = strdup(new_entry);
2312 if (vmlinux_path[vmlinux_path__nr_entries] == NULL)
2313 return -1;
2314 ++vmlinux_path__nr_entries;
2315
2316 return 0;
2317 }
2318
vmlinux_path__init(struct perf_env * env)2319 static int vmlinux_path__init(struct perf_env *env)
2320 {
2321 struct utsname uts;
2322 char bf[PATH_MAX];
2323 char *kernel_version;
2324 unsigned int i;
2325
2326 vmlinux_path = malloc(sizeof(char *) * (ARRAY_SIZE(vmlinux_paths) +
2327 ARRAY_SIZE(vmlinux_paths_upd)));
2328 if (vmlinux_path == NULL)
2329 return -1;
2330
2331 for (i = 0; i < ARRAY_SIZE(vmlinux_paths); i++)
2332 if (vmlinux_path__add(vmlinux_paths[i]) < 0)
2333 goto out_fail;
2334
2335 /* only try kernel version if no symfs was given */
2336 if (symbol_conf.symfs[0] != 0)
2337 return 0;
2338
2339 if (env) {
2340 kernel_version = env->os_release;
2341 } else {
2342 if (uname(&uts) < 0)
2343 goto out_fail;
2344
2345 kernel_version = uts.release;
2346 }
2347
2348 for (i = 0; i < ARRAY_SIZE(vmlinux_paths_upd); i++) {
2349 snprintf(bf, sizeof(bf), vmlinux_paths_upd[i], kernel_version);
2350 if (vmlinux_path__add(bf) < 0)
2351 goto out_fail;
2352 }
2353
2354 return 0;
2355
2356 out_fail:
2357 vmlinux_path__exit();
2358 return -1;
2359 }
2360
setup_list(struct strlist ** list,const char * list_str,const char * list_name)2361 int setup_list(struct strlist **list, const char *list_str,
2362 const char *list_name)
2363 {
2364 if (list_str == NULL)
2365 return 0;
2366
2367 *list = strlist__new(list_str, NULL);
2368 if (!*list) {
2369 pr_err("problems parsing %s list\n", list_name);
2370 return -1;
2371 }
2372
2373 symbol_conf.has_filter = true;
2374 return 0;
2375 }
2376
setup_intlist(struct intlist ** list,const char * list_str,const char * list_name)2377 int setup_intlist(struct intlist **list, const char *list_str,
2378 const char *list_name)
2379 {
2380 if (list_str == NULL)
2381 return 0;
2382
2383 *list = intlist__new(list_str);
2384 if (!*list) {
2385 pr_err("problems parsing %s list\n", list_name);
2386 return -1;
2387 }
2388 return 0;
2389 }
2390
setup_addrlist(struct intlist ** addr_list,struct strlist * sym_list)2391 static int setup_addrlist(struct intlist **addr_list, struct strlist *sym_list)
2392 {
2393 struct str_node *pos, *tmp;
2394 unsigned long val;
2395 char *sep;
2396 const char *end;
2397 int i = 0, err;
2398
2399 *addr_list = intlist__new(NULL);
2400 if (!*addr_list)
2401 return -1;
2402
2403 strlist__for_each_entry_safe(pos, tmp, sym_list) {
2404 errno = 0;
2405 val = strtoul(pos->s, &sep, 16);
2406 if (errno || (sep == pos->s))
2407 continue;
2408
2409 if (*sep != '\0') {
2410 end = pos->s + strlen(pos->s) - 1;
2411 while (end >= sep && isspace(*end))
2412 end--;
2413
2414 if (end >= sep)
2415 continue;
2416 }
2417
2418 err = intlist__add(*addr_list, val);
2419 if (err)
2420 break;
2421
2422 strlist__remove(sym_list, pos);
2423 i++;
2424 }
2425
2426 if (i == 0) {
2427 intlist__delete(*addr_list);
2428 *addr_list = NULL;
2429 }
2430
2431 return 0;
2432 }
2433
symbol__read_kptr_restrict(void)2434 static bool symbol__read_kptr_restrict(void)
2435 {
2436 bool value = false;
2437 FILE *fp = fopen("/proc/sys/kernel/kptr_restrict", "r");
2438 bool used_root;
2439 bool cap_syslog = perf_cap__capable(CAP_SYSLOG, &used_root);
2440
2441 if (fp != NULL) {
2442 char line[8];
2443
2444 if (fgets(line, sizeof(line), fp) != NULL)
2445 value = cap_syslog ? (atoi(line) >= 2) : (atoi(line) != 0);
2446
2447 fclose(fp);
2448 }
2449
2450 /* Per kernel/kallsyms.c:
2451 * we also restrict when perf_event_paranoid > 1 w/o CAP_SYSLOG
2452 */
2453 if (perf_event_paranoid() > 1 && !cap_syslog)
2454 value = true;
2455
2456 return value;
2457 }
2458
symbol__annotation_init(void)2459 int symbol__annotation_init(void)
2460 {
2461 if (symbol_conf.init_annotation)
2462 return 0;
2463
2464 if (symbol_conf.initialized) {
2465 pr_err("Annotation needs to be init before symbol__init()\n");
2466 return -1;
2467 }
2468
2469 symbol_conf.priv_size += sizeof(struct annotation);
2470 symbol_conf.init_annotation = true;
2471 return 0;
2472 }
2473
symbol__init(struct perf_env * env)2474 int symbol__init(struct perf_env *env)
2475 {
2476 const char *symfs;
2477
2478 if (symbol_conf.initialized)
2479 return 0;
2480
2481 symbol_conf.priv_size = PERF_ALIGN(symbol_conf.priv_size, sizeof(u64));
2482
2483 symbol__elf_init();
2484
2485 if (symbol_conf.try_vmlinux_path && vmlinux_path__init(env) < 0)
2486 return -1;
2487
2488 if (symbol_conf.field_sep && *symbol_conf.field_sep == '.') {
2489 pr_err("'.' is the only non valid --field-separator argument\n");
2490 return -1;
2491 }
2492
2493 if (setup_list(&symbol_conf.dso_list,
2494 symbol_conf.dso_list_str, "dso") < 0)
2495 return -1;
2496
2497 if (setup_list(&symbol_conf.comm_list,
2498 symbol_conf.comm_list_str, "comm") < 0)
2499 goto out_free_dso_list;
2500
2501 if (setup_intlist(&symbol_conf.pid_list,
2502 symbol_conf.pid_list_str, "pid") < 0)
2503 goto out_free_comm_list;
2504
2505 if (setup_intlist(&symbol_conf.tid_list,
2506 symbol_conf.tid_list_str, "tid") < 0)
2507 goto out_free_pid_list;
2508
2509 if (setup_list(&symbol_conf.sym_list,
2510 symbol_conf.sym_list_str, "symbol") < 0)
2511 goto out_free_tid_list;
2512
2513 if (symbol_conf.sym_list &&
2514 setup_addrlist(&symbol_conf.addr_list, symbol_conf.sym_list) < 0)
2515 goto out_free_sym_list;
2516
2517 if (setup_list(&symbol_conf.bt_stop_list,
2518 symbol_conf.bt_stop_list_str, "symbol") < 0)
2519 goto out_free_sym_list;
2520
2521 /*
2522 * A path to symbols of "/" is identical to ""
2523 * reset here for simplicity.
2524 */
2525 symfs = realpath(symbol_conf.symfs, NULL);
2526 if (symfs == NULL)
2527 symfs = symbol_conf.symfs;
2528 if (strcmp(symfs, "/") == 0)
2529 symbol_conf.symfs = "";
2530 if (symfs != symbol_conf.symfs)
2531 free((void *)symfs);
2532
2533 symbol_conf.kptr_restrict = symbol__read_kptr_restrict();
2534
2535 symbol_conf.initialized = true;
2536 return 0;
2537
2538 out_free_sym_list:
2539 strlist__delete(symbol_conf.sym_list);
2540 intlist__delete(symbol_conf.addr_list);
2541 out_free_tid_list:
2542 intlist__delete(symbol_conf.tid_list);
2543 out_free_pid_list:
2544 intlist__delete(symbol_conf.pid_list);
2545 out_free_comm_list:
2546 strlist__delete(symbol_conf.comm_list);
2547 out_free_dso_list:
2548 strlist__delete(symbol_conf.dso_list);
2549 return -1;
2550 }
2551
symbol__exit(void)2552 void symbol__exit(void)
2553 {
2554 if (!symbol_conf.initialized)
2555 return;
2556 strlist__delete(symbol_conf.bt_stop_list);
2557 strlist__delete(symbol_conf.sym_list);
2558 strlist__delete(symbol_conf.dso_list);
2559 strlist__delete(symbol_conf.comm_list);
2560 intlist__delete(symbol_conf.tid_list);
2561 intlist__delete(symbol_conf.pid_list);
2562 intlist__delete(symbol_conf.addr_list);
2563 vmlinux_path__exit();
2564 symbol_conf.sym_list = symbol_conf.dso_list = symbol_conf.comm_list = NULL;
2565 symbol_conf.bt_stop_list = NULL;
2566 symbol_conf.initialized = false;
2567 }
2568
symbol__config_symfs(const struct option * opt __maybe_unused,const char * dir,int unset __maybe_unused)2569 int symbol__config_symfs(const struct option *opt __maybe_unused,
2570 const char *dir, int unset __maybe_unused)
2571 {
2572 char *bf = NULL;
2573 int ret;
2574
2575 symbol_conf.symfs = strdup(dir);
2576 if (symbol_conf.symfs == NULL)
2577 return -ENOMEM;
2578
2579 /* skip the locally configured cache if a symfs is given, and
2580 * config buildid dir to symfs/.debug
2581 */
2582 ret = asprintf(&bf, "%s/%s", dir, ".debug");
2583 if (ret < 0)
2584 return -ENOMEM;
2585
2586 set_buildid_dir(bf);
2587
2588 free(bf);
2589 return 0;
2590 }
2591
2592 /*
2593 * Checks that user supplied symbol kernel files are accessible because
2594 * the default mechanism for accessing elf files fails silently. i.e. if
2595 * debug syms for a build ID aren't found perf carries on normally. When
2596 * they are user supplied we should assume that the user doesn't want to
2597 * silently fail.
2598 */
symbol__validate_sym_arguments(void)2599 int symbol__validate_sym_arguments(void)
2600 {
2601 if (symbol_conf.vmlinux_name &&
2602 access(symbol_conf.vmlinux_name, R_OK)) {
2603 pr_err("Invalid file: %s\n", symbol_conf.vmlinux_name);
2604 return -EINVAL;
2605 }
2606 if (symbol_conf.kallsyms_name &&
2607 access(symbol_conf.kallsyms_name, R_OK)) {
2608 pr_err("Invalid file: %s\n", symbol_conf.kallsyms_name);
2609 return -EINVAL;
2610 }
2611 return 0;
2612 }
2613