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 /* Prefer a non weak symbol over a weak one */
158 a = syma->binding == STB_WEAK;
159 b = symb->binding == STB_WEAK;
160 if (b && !a)
161 return SYMBOL_A;
162 if (a && !b)
163 return SYMBOL_B;
164
165 /* Prefer a global symbol over a non global one */
166 a = syma->binding == STB_GLOBAL;
167 b = symb->binding == STB_GLOBAL;
168 if (a && !b)
169 return SYMBOL_A;
170 if (b && !a)
171 return SYMBOL_B;
172
173 /* Prefer a symbol with less underscores */
174 a = prefix_underscores_count(syma->name);
175 b = prefix_underscores_count(symb->name);
176 if (b > a)
177 return SYMBOL_A;
178 else if (a > b)
179 return SYMBOL_B;
180
181 /* Choose the symbol with the longest name */
182 na = strlen(syma->name);
183 nb = strlen(symb->name);
184 if (na > nb)
185 return SYMBOL_A;
186 else if (na < nb)
187 return SYMBOL_B;
188
189 return arch__choose_best_symbol(syma, symb);
190 }
191
symbols__fixup_duplicate(struct rb_root_cached * symbols)192 void symbols__fixup_duplicate(struct rb_root_cached *symbols)
193 {
194 struct rb_node *nd;
195 struct symbol *curr, *next;
196
197 if (symbol_conf.allow_aliases)
198 return;
199
200 nd = rb_first_cached(symbols);
201
202 while (nd) {
203 curr = rb_entry(nd, struct symbol, rb_node);
204 again:
205 nd = rb_next(&curr->rb_node);
206 if (!nd)
207 break;
208
209 next = rb_entry(nd, struct symbol, rb_node);
210 if (curr->start != next->start)
211 continue;
212
213 if (choose_best_symbol(curr, next) == SYMBOL_A) {
214 if (next->type == STT_GNU_IFUNC)
215 curr->ifunc_alias = true;
216 rb_erase_cached(&next->rb_node, symbols);
217 symbol__delete(next);
218 goto again;
219 } else {
220 if (curr->type == STT_GNU_IFUNC)
221 next->ifunc_alias = true;
222 nd = rb_next(&curr->rb_node);
223 rb_erase_cached(&curr->rb_node, symbols);
224 symbol__delete(curr);
225 }
226 }
227 }
228
229 /* Update zero-sized symbols using the address of the next symbol */
symbols__fixup_end(struct rb_root_cached * symbols,bool is_kallsyms)230 void symbols__fixup_end(struct rb_root_cached *symbols, bool is_kallsyms)
231 {
232 struct rb_node *nd, *prevnd = rb_first_cached(symbols);
233 struct symbol *curr, *prev;
234
235 if (prevnd == NULL)
236 return;
237
238 curr = rb_entry(prevnd, struct symbol, rb_node);
239
240 for (nd = rb_next(prevnd); nd; nd = rb_next(nd)) {
241 prev = curr;
242 curr = rb_entry(nd, struct symbol, rb_node);
243
244 /*
245 * On some architecture kernel text segment start is located at
246 * some low memory address, while modules are located at high
247 * memory addresses (or vice versa). The gap between end of
248 * kernel text segment and beginning of first module's text
249 * segment is very big. Therefore do not fill this gap and do
250 * not assign it to the kernel dso map (kallsyms).
251 *
252 * Also BPF code can be allocated separately from text segments
253 * and modules. So the last entry in a module should not fill
254 * the gap too.
255 *
256 * In kallsyms, it determines module symbols using '[' character
257 * like in:
258 * ffffffffc1937000 T hdmi_driver_init [snd_hda_codec_hdmi]
259 */
260 if (prev->end == prev->start) {
261 const char *prev_mod;
262 const char *curr_mod;
263
264 if (!is_kallsyms) {
265 prev->end = curr->start;
266 continue;
267 }
268
269 prev_mod = strchr(prev->name, '[');
270 curr_mod = strchr(curr->name, '[');
271
272 /* Last kernel/module symbol mapped to end of page */
273 if (!prev_mod != !curr_mod)
274 prev->end = roundup(prev->end + 4096, 4096);
275 /* Last symbol in the previous module */
276 else if (prev_mod && strcmp(prev_mod, curr_mod))
277 prev->end = roundup(prev->end + 4096, 4096);
278 else
279 prev->end = curr->start;
280
281 pr_debug4("%s sym:%s end:%#" PRIx64 "\n",
282 __func__, prev->name, prev->end);
283 }
284 }
285
286 /* Last entry */
287 if (curr->end == curr->start)
288 curr->end = roundup(curr->start, 4096) + 4096;
289 }
290
symbol__new(u64 start,u64 len,u8 binding,u8 type,const char * name)291 struct symbol *symbol__new(u64 start, u64 len, u8 binding, u8 type, const char *name)
292 {
293 size_t namelen = strlen(name) + 1;
294 struct symbol *sym = calloc(1, (symbol_conf.priv_size +
295 sizeof(*sym) + namelen));
296 if (sym == NULL)
297 return NULL;
298
299 if (symbol_conf.priv_size) {
300 if (symbol_conf.init_annotation) {
301 struct annotation *notes = (void *)sym;
302 annotation__init(notes);
303 }
304 sym = ((void *)sym) + symbol_conf.priv_size;
305 }
306
307 sym->start = start;
308 sym->end = len ? start + len : start;
309 sym->type = type;
310 sym->binding = binding;
311 sym->namelen = namelen - 1;
312
313 pr_debug4("%s: %s %#" PRIx64 "-%#" PRIx64 "\n",
314 __func__, name, start, sym->end);
315 memcpy(sym->name, name, namelen);
316
317 return sym;
318 }
319
symbol__delete(struct symbol * sym)320 void symbol__delete(struct symbol *sym)
321 {
322 if (symbol_conf.priv_size) {
323 if (symbol_conf.init_annotation) {
324 struct annotation *notes = symbol__annotation(sym);
325
326 annotation__exit(notes);
327 }
328 }
329 free(((void *)sym) - symbol_conf.priv_size);
330 }
331
symbols__delete(struct rb_root_cached * symbols)332 void symbols__delete(struct rb_root_cached *symbols)
333 {
334 struct symbol *pos;
335 struct rb_node *next = rb_first_cached(symbols);
336
337 while (next) {
338 pos = rb_entry(next, struct symbol, rb_node);
339 next = rb_next(&pos->rb_node);
340 rb_erase_cached(&pos->rb_node, symbols);
341 symbol__delete(pos);
342 }
343 }
344
__symbols__insert(struct rb_root_cached * symbols,struct symbol * sym,bool kernel)345 void __symbols__insert(struct rb_root_cached *symbols,
346 struct symbol *sym, bool kernel)
347 {
348 struct rb_node **p = &symbols->rb_root.rb_node;
349 struct rb_node *parent = NULL;
350 const u64 ip = sym->start;
351 struct symbol *s;
352 bool leftmost = true;
353
354 if (kernel) {
355 const char *name = sym->name;
356 /*
357 * ppc64 uses function descriptors and appends a '.' to the
358 * start of every instruction address. Remove it.
359 */
360 if (name[0] == '.')
361 name++;
362 sym->idle = symbol__is_idle(name);
363 }
364
365 while (*p != NULL) {
366 parent = *p;
367 s = rb_entry(parent, struct symbol, rb_node);
368 if (ip < s->start)
369 p = &(*p)->rb_left;
370 else {
371 p = &(*p)->rb_right;
372 leftmost = false;
373 }
374 }
375 rb_link_node(&sym->rb_node, parent, p);
376 rb_insert_color_cached(&sym->rb_node, symbols, leftmost);
377 }
378
symbols__insert(struct rb_root_cached * symbols,struct symbol * sym)379 void symbols__insert(struct rb_root_cached *symbols, struct symbol *sym)
380 {
381 __symbols__insert(symbols, sym, false);
382 }
383
symbols__find(struct rb_root_cached * symbols,u64 ip)384 static struct symbol *symbols__find(struct rb_root_cached *symbols, u64 ip)
385 {
386 struct rb_node *n;
387
388 if (symbols == NULL)
389 return NULL;
390
391 n = symbols->rb_root.rb_node;
392
393 while (n) {
394 struct symbol *s = rb_entry(n, struct symbol, rb_node);
395
396 if (ip < s->start)
397 n = n->rb_left;
398 else if (ip > s->end || (ip == s->end && ip != s->start))
399 n = n->rb_right;
400 else
401 return s;
402 }
403
404 return NULL;
405 }
406
symbols__first(struct rb_root_cached * symbols)407 static struct symbol *symbols__first(struct rb_root_cached *symbols)
408 {
409 struct rb_node *n = rb_first_cached(symbols);
410
411 if (n)
412 return rb_entry(n, struct symbol, rb_node);
413
414 return NULL;
415 }
416
symbols__last(struct rb_root_cached * symbols)417 static struct symbol *symbols__last(struct rb_root_cached *symbols)
418 {
419 struct rb_node *n = rb_last(&symbols->rb_root);
420
421 if (n)
422 return rb_entry(n, struct symbol, rb_node);
423
424 return NULL;
425 }
426
symbols__next(struct symbol * sym)427 static struct symbol *symbols__next(struct symbol *sym)
428 {
429 struct rb_node *n = rb_next(&sym->rb_node);
430
431 if (n)
432 return rb_entry(n, struct symbol, rb_node);
433
434 return NULL;
435 }
436
symbols__sort_name_cmp(const void * vlhs,const void * vrhs)437 static int symbols__sort_name_cmp(const void *vlhs, const void *vrhs)
438 {
439 const struct symbol *lhs = *((const struct symbol **)vlhs);
440 const struct symbol *rhs = *((const struct symbol **)vrhs);
441
442 return strcmp(lhs->name, rhs->name);
443 }
444
symbols__sort_by_name(struct rb_root_cached * source,size_t * len)445 static struct symbol **symbols__sort_by_name(struct rb_root_cached *source, size_t *len)
446 {
447 struct rb_node *nd;
448 struct symbol **result;
449 size_t i = 0, size = 0;
450
451 for (nd = rb_first_cached(source); nd; nd = rb_next(nd))
452 size++;
453
454 result = malloc(sizeof(*result) * size);
455 if (!result)
456 return NULL;
457
458 for (nd = rb_first_cached(source); nd; nd = rb_next(nd)) {
459 struct symbol *pos = rb_entry(nd, struct symbol, rb_node);
460
461 result[i++] = pos;
462 }
463 qsort(result, size, sizeof(*result), symbols__sort_name_cmp);
464 *len = size;
465 return result;
466 }
467
symbol__match_symbol_name(const char * name,const char * str,enum symbol_tag_include includes)468 int symbol__match_symbol_name(const char *name, const char *str,
469 enum symbol_tag_include includes)
470 {
471 const char *versioning;
472
473 if (includes == SYMBOL_TAG_INCLUDE__DEFAULT_ONLY &&
474 (versioning = strstr(name, "@@"))) {
475 int len = strlen(str);
476
477 if (len < versioning - name)
478 len = versioning - name;
479
480 return arch__compare_symbol_names_n(name, str, len);
481 } else
482 return arch__compare_symbol_names(name, str);
483 }
484
symbols__find_by_name(struct symbol * symbols[],size_t symbols_len,const char * name,enum symbol_tag_include includes,size_t * found_idx)485 static struct symbol *symbols__find_by_name(struct symbol *symbols[],
486 size_t symbols_len,
487 const char *name,
488 enum symbol_tag_include includes,
489 size_t *found_idx)
490 {
491 size_t i, lower = 0, upper = symbols_len;
492 struct symbol *s = NULL;
493
494 if (found_idx)
495 *found_idx = SIZE_MAX;
496
497 if (!symbols_len)
498 return NULL;
499
500 while (lower < upper) {
501 int cmp;
502
503 i = (lower + upper) / 2;
504 cmp = symbol__match_symbol_name(symbols[i]->name, name, includes);
505
506 if (cmp > 0)
507 upper = i;
508 else if (cmp < 0)
509 lower = i + 1;
510 else {
511 if (found_idx)
512 *found_idx = i;
513 s = symbols[i];
514 break;
515 }
516 }
517 if (s && includes != SYMBOL_TAG_INCLUDE__DEFAULT_ONLY) {
518 /* return first symbol that has same name (if any) */
519 for (; i > 0; i--) {
520 struct symbol *tmp = symbols[i - 1];
521
522 if (!arch__compare_symbol_names(tmp->name, s->name)) {
523 if (found_idx)
524 *found_idx = i - 1;
525 s = tmp;
526 } else
527 break;
528 }
529 }
530 assert(!found_idx || !s || s == symbols[*found_idx]);
531 return s;
532 }
533
dso__reset_find_symbol_cache(struct dso * dso)534 void dso__reset_find_symbol_cache(struct dso *dso)
535 {
536 dso__set_last_find_result_addr(dso, 0);
537 dso__set_last_find_result_symbol(dso, NULL);
538 }
539
dso__insert_symbol(struct dso * dso,struct symbol * sym)540 void dso__insert_symbol(struct dso *dso, struct symbol *sym)
541 {
542 __symbols__insert(dso__symbols(dso), sym, dso__kernel(dso));
543
544 /* update the symbol cache if necessary */
545 if (dso__last_find_result_addr(dso) >= sym->start &&
546 (dso__last_find_result_addr(dso) < sym->end ||
547 sym->start == sym->end)) {
548 dso__set_last_find_result_symbol(dso, sym);
549 }
550 }
551
dso__delete_symbol(struct dso * dso,struct symbol * sym)552 void dso__delete_symbol(struct dso *dso, struct symbol *sym)
553 {
554 rb_erase_cached(&sym->rb_node, dso__symbols(dso));
555 symbol__delete(sym);
556 dso__reset_find_symbol_cache(dso);
557 }
558
dso__find_symbol(struct dso * dso,u64 addr)559 struct symbol *dso__find_symbol(struct dso *dso, u64 addr)
560 {
561 if (dso__last_find_result_addr(dso) != addr || dso__last_find_result_symbol(dso) == NULL) {
562 dso__set_last_find_result_addr(dso, addr);
563 dso__set_last_find_result_symbol(dso, symbols__find(dso__symbols(dso), addr));
564 }
565
566 return dso__last_find_result_symbol(dso);
567 }
568
dso__find_symbol_nocache(struct dso * dso,u64 addr)569 struct symbol *dso__find_symbol_nocache(struct dso *dso, u64 addr)
570 {
571 return symbols__find(dso__symbols(dso), addr);
572 }
573
dso__first_symbol(struct dso * dso)574 struct symbol *dso__first_symbol(struct dso *dso)
575 {
576 return symbols__first(dso__symbols(dso));
577 }
578
dso__last_symbol(struct dso * dso)579 struct symbol *dso__last_symbol(struct dso *dso)
580 {
581 return symbols__last(dso__symbols(dso));
582 }
583
dso__next_symbol(struct symbol * sym)584 struct symbol *dso__next_symbol(struct symbol *sym)
585 {
586 return symbols__next(sym);
587 }
588
dso__next_symbol_by_name(struct dso * dso,size_t * idx)589 struct symbol *dso__next_symbol_by_name(struct dso *dso, size_t *idx)
590 {
591 if (*idx + 1 >= dso__symbol_names_len(dso))
592 return NULL;
593
594 ++*idx;
595 return dso__symbol_names(dso)[*idx];
596 }
597
598 /*
599 * Returns first symbol that matched with @name.
600 */
dso__find_symbol_by_name(struct dso * dso,const char * name,size_t * idx)601 struct symbol *dso__find_symbol_by_name(struct dso *dso, const char *name, size_t *idx)
602 {
603 struct symbol *s = symbols__find_by_name(dso__symbol_names(dso),
604 dso__symbol_names_len(dso),
605 name, SYMBOL_TAG_INCLUDE__NONE, idx);
606 if (!s) {
607 s = symbols__find_by_name(dso__symbol_names(dso), dso__symbol_names_len(dso),
608 name, SYMBOL_TAG_INCLUDE__DEFAULT_ONLY, idx);
609 }
610 return s;
611 }
612
dso__sort_by_name(struct dso * dso)613 void dso__sort_by_name(struct dso *dso)
614 {
615 mutex_lock(dso__lock(dso));
616 if (!dso__sorted_by_name(dso)) {
617 size_t len;
618
619 dso__set_symbol_names(dso, symbols__sort_by_name(dso__symbols(dso), &len));
620 if (dso__symbol_names(dso)) {
621 dso__set_symbol_names_len(dso, len);
622 dso__set_sorted_by_name(dso);
623 }
624 }
625 mutex_unlock(dso__lock(dso));
626 }
627
628 /*
629 * While we find nice hex chars, build a long_val.
630 * Return number of chars processed.
631 */
hex2u64(const char * ptr,u64 * long_val)632 static int hex2u64(const char *ptr, u64 *long_val)
633 {
634 char *p;
635
636 *long_val = strtoull(ptr, &p, 16);
637
638 return p - ptr;
639 }
640
641
modules__parse(const char * filename,void * arg,int (* process_module)(void * arg,const char * name,u64 start,u64 size))642 int modules__parse(const char *filename, void *arg,
643 int (*process_module)(void *arg, const char *name,
644 u64 start, u64 size))
645 {
646 char *line = NULL;
647 size_t n;
648 FILE *file;
649 int err = 0;
650
651 file = fopen(filename, "r");
652 if (file == NULL)
653 return -1;
654
655 while (1) {
656 char name[PATH_MAX];
657 u64 start, size;
658 char *sep, *endptr;
659 ssize_t line_len;
660
661 line_len = getline(&line, &n, file);
662 if (line_len < 0) {
663 if (feof(file))
664 break;
665 err = -1;
666 goto out;
667 }
668
669 if (!line) {
670 err = -1;
671 goto out;
672 }
673
674 line[--line_len] = '\0'; /* \n */
675
676 sep = strrchr(line, 'x');
677 if (sep == NULL)
678 continue;
679
680 hex2u64(sep + 1, &start);
681
682 sep = strchr(line, ' ');
683 if (sep == NULL)
684 continue;
685
686 *sep = '\0';
687
688 scnprintf(name, sizeof(name), "[%s]", line);
689
690 size = strtoul(sep + 1, &endptr, 0);
691 if (*endptr != ' ' && *endptr != '\t')
692 continue;
693
694 err = process_module(arg, name, start, size);
695 if (err)
696 break;
697 }
698 out:
699 free(line);
700 fclose(file);
701 return err;
702 }
703
704 /*
705 * These are symbols in the kernel image, so make sure that
706 * sym is from a kernel DSO.
707 */
symbol__is_idle(const char * name)708 static bool symbol__is_idle(const char *name)
709 {
710 const char * const idle_symbols[] = {
711 "acpi_idle_do_entry",
712 "acpi_processor_ffh_cstate_enter",
713 "arch_cpu_idle",
714 "cpu_idle",
715 "cpu_startup_entry",
716 "idle_cpu",
717 "intel_idle",
718 "intel_idle_ibrs",
719 "default_idle",
720 "native_safe_halt",
721 "enter_idle",
722 "exit_idle",
723 "mwait_idle",
724 "mwait_idle_with_hints",
725 "mwait_idle_with_hints.constprop.0",
726 "poll_idle",
727 "ppc64_runlatch_off",
728 "pseries_dedicated_idle_sleep",
729 "psw_idle",
730 "psw_idle_exit",
731 NULL
732 };
733 int i;
734 static struct strlist *idle_symbols_list;
735
736 if (idle_symbols_list)
737 return strlist__has_entry(idle_symbols_list, name);
738
739 idle_symbols_list = strlist__new(NULL, NULL);
740
741 for (i = 0; idle_symbols[i]; i++)
742 strlist__add(idle_symbols_list, idle_symbols[i]);
743
744 return strlist__has_entry(idle_symbols_list, name);
745 }
746
map__process_kallsym_symbol(void * arg,const char * name,char type,u64 start)747 static int map__process_kallsym_symbol(void *arg, const char *name,
748 char type, u64 start)
749 {
750 struct symbol *sym;
751 struct dso *dso = arg;
752 struct rb_root_cached *root = dso__symbols(dso);
753
754 if (!symbol_type__filter(type))
755 return 0;
756
757 /* Ignore local symbols for ARM modules */
758 if (name[0] == '$')
759 return 0;
760
761 /*
762 * module symbols are not sorted so we add all
763 * symbols, setting length to 0, and rely on
764 * symbols__fixup_end() to fix it up.
765 */
766 sym = symbol__new(start, 0, kallsyms2elf_binding(type), kallsyms2elf_type(type), name);
767 if (sym == NULL)
768 return -ENOMEM;
769 /*
770 * We will pass the symbols to the filter later, in
771 * map__split_kallsyms, when we have split the maps per module
772 */
773 __symbols__insert(root, sym, !strchr(name, '['));
774
775 return 0;
776 }
777
778 /*
779 * Loads the function entries in /proc/kallsyms into kernel_map->dso,
780 * so that we can in the next step set the symbol ->end address and then
781 * call kernel_maps__split_kallsyms.
782 */
dso__load_all_kallsyms(struct dso * dso,const char * filename)783 static int dso__load_all_kallsyms(struct dso *dso, const char *filename)
784 {
785 return kallsyms__parse(filename, dso, map__process_kallsym_symbol);
786 }
787
maps__split_kallsyms_for_kcore(struct maps * kmaps,struct dso * dso)788 static int maps__split_kallsyms_for_kcore(struct maps *kmaps, struct dso *dso)
789 {
790 struct symbol *pos;
791 int count = 0;
792 struct rb_root_cached *root = dso__symbols(dso);
793 struct rb_root_cached old_root = *root;
794 struct rb_node *next = rb_first_cached(root);
795
796 if (!kmaps)
797 return -1;
798
799 *root = RB_ROOT_CACHED;
800
801 while (next) {
802 struct map *curr_map;
803 struct dso *curr_map_dso;
804 char *module;
805
806 pos = rb_entry(next, struct symbol, rb_node);
807 next = rb_next(&pos->rb_node);
808
809 rb_erase_cached(&pos->rb_node, &old_root);
810 RB_CLEAR_NODE(&pos->rb_node);
811 module = strchr(pos->name, '\t');
812 if (module)
813 *module = '\0';
814
815 curr_map = maps__find(kmaps, pos->start);
816
817 if (!curr_map) {
818 symbol__delete(pos);
819 continue;
820 }
821 curr_map_dso = map__dso(curr_map);
822 pos->start -= map__start(curr_map) - map__pgoff(curr_map);
823 if (pos->end > map__end(curr_map))
824 pos->end = map__end(curr_map);
825 if (pos->end)
826 pos->end -= map__start(curr_map) - map__pgoff(curr_map);
827 symbols__insert(dso__symbols(curr_map_dso), pos);
828 ++count;
829 map__put(curr_map);
830 }
831
832 /* Symbols have been adjusted */
833 dso__set_adjust_symbols(dso, true);
834
835 return count;
836 }
837
838 /*
839 * Split the symbols into maps, making sure there are no overlaps, i.e. the
840 * kernel range is broken in several maps, named [kernel].N, as we don't have
841 * the original ELF section names vmlinux have.
842 */
maps__split_kallsyms(struct maps * kmaps,struct dso * dso,u64 delta,struct map * initial_map)843 static int maps__split_kallsyms(struct maps *kmaps, struct dso *dso, u64 delta,
844 struct map *initial_map)
845 {
846 struct machine *machine;
847 struct map *curr_map = map__get(initial_map);
848 struct symbol *pos;
849 int count = 0, moved = 0;
850 struct rb_root_cached *root = dso__symbols(dso);
851 struct rb_node *next = rb_first_cached(root);
852 int kernel_range = 0;
853 bool x86_64;
854
855 if (!kmaps)
856 return -1;
857
858 machine = maps__machine(kmaps);
859
860 x86_64 = machine__is(machine, "x86_64");
861
862 while (next) {
863 char *module;
864
865 pos = rb_entry(next, struct symbol, rb_node);
866 next = rb_next(&pos->rb_node);
867
868 module = strchr(pos->name, '\t');
869 if (module) {
870 struct dso *curr_map_dso;
871
872 if (!symbol_conf.use_modules)
873 goto discard_symbol;
874
875 *module++ = '\0';
876 curr_map_dso = map__dso(curr_map);
877 if (strcmp(dso__short_name(curr_map_dso), module)) {
878 if (!RC_CHK_EQUAL(curr_map, initial_map) &&
879 dso__kernel(dso) == DSO_SPACE__KERNEL_GUEST &&
880 machine__is_default_guest(machine)) {
881 /*
882 * We assume all symbols of a module are
883 * continuous in * kallsyms, so curr_map
884 * points to a module and all its
885 * symbols are in its kmap. Mark it as
886 * loaded.
887 */
888 dso__set_loaded(curr_map_dso);
889 }
890
891 map__zput(curr_map);
892 curr_map = maps__find_by_name(kmaps, module);
893 if (curr_map == NULL) {
894 pr_debug("%s/proc/{kallsyms,modules} "
895 "inconsistency while looking "
896 "for \"%s\" module!\n",
897 machine->root_dir, module);
898 curr_map = map__get(initial_map);
899 goto discard_symbol;
900 }
901 curr_map_dso = map__dso(curr_map);
902 if (dso__loaded(curr_map_dso) &&
903 !machine__is_default_guest(machine))
904 goto discard_symbol;
905 }
906 /*
907 * So that we look just like we get from .ko files,
908 * i.e. not prelinked, relative to initial_map->start.
909 */
910 pos->start = map__map_ip(curr_map, pos->start);
911 pos->end = map__map_ip(curr_map, pos->end);
912 } else if (x86_64 && is_entry_trampoline(pos->name)) {
913 /*
914 * These symbols are not needed anymore since the
915 * trampoline maps refer to the text section and it's
916 * symbols instead. Avoid having to deal with
917 * relocations, and the assumption that the first symbol
918 * is the start of kernel text, by simply removing the
919 * symbols at this point.
920 */
921 goto discard_symbol;
922 } else if (!RC_CHK_EQUAL(curr_map, initial_map)) {
923 char dso_name[PATH_MAX];
924 struct dso *ndso;
925
926 if (delta) {
927 /* Kernel was relocated at boot time */
928 pos->start -= delta;
929 pos->end -= delta;
930 }
931
932 if (count == 0) {
933 map__zput(curr_map);
934 curr_map = map__get(initial_map);
935 goto add_symbol;
936 }
937
938 if (dso__kernel(dso) == DSO_SPACE__KERNEL_GUEST)
939 snprintf(dso_name, sizeof(dso_name),
940 "[guest.kernel].%d",
941 kernel_range++);
942 else
943 snprintf(dso_name, sizeof(dso_name),
944 "[kernel].%d",
945 kernel_range++);
946
947 ndso = dso__new(dso_name);
948 map__zput(curr_map);
949 if (ndso == NULL)
950 return -1;
951
952 dso__set_kernel(ndso, dso__kernel(dso));
953
954 curr_map = map__new2(pos->start, ndso);
955 if (curr_map == NULL) {
956 dso__put(ndso);
957 return -1;
958 }
959
960 map__set_mapping_type(curr_map, MAPPING_TYPE__IDENTITY);
961 if (maps__insert(kmaps, curr_map)) {
962 map__zput(curr_map);
963 dso__put(ndso);
964 return -1;
965 }
966 ++kernel_range;
967 } else if (delta) {
968 /* Kernel was relocated at boot time */
969 pos->start -= delta;
970 pos->end -= delta;
971 }
972 add_symbol:
973 if (!RC_CHK_EQUAL(curr_map, initial_map)) {
974 struct dso *curr_map_dso = map__dso(curr_map);
975
976 rb_erase_cached(&pos->rb_node, root);
977 symbols__insert(dso__symbols(curr_map_dso), pos);
978 ++moved;
979 } else
980 ++count;
981
982 continue;
983 discard_symbol:
984 rb_erase_cached(&pos->rb_node, root);
985 symbol__delete(pos);
986 }
987
988 if (!RC_CHK_EQUAL(curr_map, initial_map) &&
989 dso__kernel(dso) == DSO_SPACE__KERNEL_GUEST &&
990 machine__is_default_guest(maps__machine(kmaps))) {
991 dso__set_loaded(map__dso(curr_map));
992 }
993 map__put(curr_map);
994 return count + moved;
995 }
996
symbol__restricted_filename(const char * filename,const char * restricted_filename)997 bool symbol__restricted_filename(const char *filename,
998 const char *restricted_filename)
999 {
1000 bool restricted = false;
1001
1002 if (symbol_conf.kptr_restrict) {
1003 char *r = realpath(filename, NULL);
1004
1005 if (r != NULL) {
1006 restricted = strcmp(r, restricted_filename) == 0;
1007 free(r);
1008 return restricted;
1009 }
1010 }
1011
1012 return restricted;
1013 }
1014
1015 struct module_info {
1016 struct rb_node rb_node;
1017 char *name;
1018 u64 start;
1019 };
1020
add_module(struct module_info * mi,struct rb_root * modules)1021 static void add_module(struct module_info *mi, struct rb_root *modules)
1022 {
1023 struct rb_node **p = &modules->rb_node;
1024 struct rb_node *parent = NULL;
1025 struct module_info *m;
1026
1027 while (*p != NULL) {
1028 parent = *p;
1029 m = rb_entry(parent, struct module_info, rb_node);
1030 if (strcmp(mi->name, m->name) < 0)
1031 p = &(*p)->rb_left;
1032 else
1033 p = &(*p)->rb_right;
1034 }
1035 rb_link_node(&mi->rb_node, parent, p);
1036 rb_insert_color(&mi->rb_node, modules);
1037 }
1038
delete_modules(struct rb_root * modules)1039 static void delete_modules(struct rb_root *modules)
1040 {
1041 struct module_info *mi;
1042 struct rb_node *next = rb_first(modules);
1043
1044 while (next) {
1045 mi = rb_entry(next, struct module_info, rb_node);
1046 next = rb_next(&mi->rb_node);
1047 rb_erase(&mi->rb_node, modules);
1048 zfree(&mi->name);
1049 free(mi);
1050 }
1051 }
1052
find_module(const char * name,struct rb_root * modules)1053 static struct module_info *find_module(const char *name,
1054 struct rb_root *modules)
1055 {
1056 struct rb_node *n = modules->rb_node;
1057
1058 while (n) {
1059 struct module_info *m;
1060 int cmp;
1061
1062 m = rb_entry(n, struct module_info, rb_node);
1063 cmp = strcmp(name, m->name);
1064 if (cmp < 0)
1065 n = n->rb_left;
1066 else if (cmp > 0)
1067 n = n->rb_right;
1068 else
1069 return m;
1070 }
1071
1072 return NULL;
1073 }
1074
__read_proc_modules(void * arg,const char * name,u64 start,u64 size __maybe_unused)1075 static int __read_proc_modules(void *arg, const char *name, u64 start,
1076 u64 size __maybe_unused)
1077 {
1078 struct rb_root *modules = arg;
1079 struct module_info *mi;
1080
1081 mi = zalloc(sizeof(struct module_info));
1082 if (!mi)
1083 return -ENOMEM;
1084
1085 mi->name = strdup(name);
1086 mi->start = start;
1087
1088 if (!mi->name) {
1089 free(mi);
1090 return -ENOMEM;
1091 }
1092
1093 add_module(mi, modules);
1094
1095 return 0;
1096 }
1097
read_proc_modules(const char * filename,struct rb_root * modules)1098 static int read_proc_modules(const char *filename, struct rb_root *modules)
1099 {
1100 if (symbol__restricted_filename(filename, "/proc/modules"))
1101 return -1;
1102
1103 if (modules__parse(filename, modules, __read_proc_modules)) {
1104 delete_modules(modules);
1105 return -1;
1106 }
1107
1108 return 0;
1109 }
1110
compare_proc_modules(const char * from,const char * to)1111 int compare_proc_modules(const char *from, const char *to)
1112 {
1113 struct rb_root from_modules = RB_ROOT;
1114 struct rb_root to_modules = RB_ROOT;
1115 struct rb_node *from_node, *to_node;
1116 struct module_info *from_m, *to_m;
1117 int ret = -1;
1118
1119 if (read_proc_modules(from, &from_modules))
1120 return -1;
1121
1122 if (read_proc_modules(to, &to_modules))
1123 goto out_delete_from;
1124
1125 from_node = rb_first(&from_modules);
1126 to_node = rb_first(&to_modules);
1127 while (from_node) {
1128 if (!to_node)
1129 break;
1130
1131 from_m = rb_entry(from_node, struct module_info, rb_node);
1132 to_m = rb_entry(to_node, struct module_info, rb_node);
1133
1134 if (from_m->start != to_m->start ||
1135 strcmp(from_m->name, to_m->name))
1136 break;
1137
1138 from_node = rb_next(from_node);
1139 to_node = rb_next(to_node);
1140 }
1141
1142 if (!from_node && !to_node)
1143 ret = 0;
1144
1145 delete_modules(&to_modules);
1146 out_delete_from:
1147 delete_modules(&from_modules);
1148
1149 return ret;
1150 }
1151
do_validate_kcore_modules_cb(struct map * old_map,void * data)1152 static int do_validate_kcore_modules_cb(struct map *old_map, void *data)
1153 {
1154 struct rb_root *modules = data;
1155 struct module_info *mi;
1156 struct dso *dso;
1157
1158 if (!__map__is_kmodule(old_map))
1159 return 0;
1160
1161 dso = map__dso(old_map);
1162 /* Module must be in memory at the same address */
1163 mi = find_module(dso__short_name(dso), modules);
1164 if (!mi || mi->start != map__start(old_map))
1165 return -EINVAL;
1166
1167 return 0;
1168 }
1169
do_validate_kcore_modules(const char * filename,struct maps * kmaps)1170 static int do_validate_kcore_modules(const char *filename, struct maps *kmaps)
1171 {
1172 struct rb_root modules = RB_ROOT;
1173 int err;
1174
1175 err = read_proc_modules(filename, &modules);
1176 if (err)
1177 return err;
1178
1179 err = maps__for_each_map(kmaps, do_validate_kcore_modules_cb, &modules);
1180
1181 delete_modules(&modules);
1182 return err;
1183 }
1184
1185 /*
1186 * If kallsyms is referenced by name then we look for filename in the same
1187 * directory.
1188 */
filename_from_kallsyms_filename(char * filename,const char * base_name,const char * kallsyms_filename)1189 static bool filename_from_kallsyms_filename(char *filename,
1190 const char *base_name,
1191 const char *kallsyms_filename)
1192 {
1193 char *name;
1194
1195 strcpy(filename, kallsyms_filename);
1196 name = strrchr(filename, '/');
1197 if (!name)
1198 return false;
1199
1200 name += 1;
1201
1202 if (!strcmp(name, "kallsyms")) {
1203 strcpy(name, base_name);
1204 return true;
1205 }
1206
1207 return false;
1208 }
1209
validate_kcore_modules(const char * kallsyms_filename,struct map * map)1210 static int validate_kcore_modules(const char *kallsyms_filename,
1211 struct map *map)
1212 {
1213 struct maps *kmaps = map__kmaps(map);
1214 char modules_filename[PATH_MAX];
1215
1216 if (!kmaps)
1217 return -EINVAL;
1218
1219 if (!filename_from_kallsyms_filename(modules_filename, "modules",
1220 kallsyms_filename))
1221 return -EINVAL;
1222
1223 if (do_validate_kcore_modules(modules_filename, kmaps))
1224 return -EINVAL;
1225
1226 return 0;
1227 }
1228
validate_kcore_addresses(const char * kallsyms_filename,struct map * map)1229 static int validate_kcore_addresses(const char *kallsyms_filename,
1230 struct map *map)
1231 {
1232 struct kmap *kmap = map__kmap(map);
1233
1234 if (!kmap)
1235 return -EINVAL;
1236
1237 if (kmap->ref_reloc_sym && kmap->ref_reloc_sym->name) {
1238 u64 start;
1239
1240 if (kallsyms__get_function_start(kallsyms_filename,
1241 kmap->ref_reloc_sym->name, &start))
1242 return -ENOENT;
1243 if (start != kmap->ref_reloc_sym->addr)
1244 return -EINVAL;
1245 }
1246
1247 return validate_kcore_modules(kallsyms_filename, map);
1248 }
1249
1250 struct kcore_mapfn_data {
1251 struct dso *dso;
1252 struct list_head maps;
1253 };
1254
kcore_mapfn(u64 start,u64 len,u64 pgoff,void * data)1255 static int kcore_mapfn(u64 start, u64 len, u64 pgoff, void *data)
1256 {
1257 struct kcore_mapfn_data *md = data;
1258 struct map_list_node *list_node = map_list_node__new();
1259
1260 if (!list_node)
1261 return -ENOMEM;
1262
1263 list_node->map = map__new2(start, md->dso);
1264 if (!list_node->map) {
1265 free(list_node);
1266 return -ENOMEM;
1267 }
1268
1269 map__set_end(list_node->map, map__start(list_node->map) + len);
1270 map__set_pgoff(list_node->map, pgoff);
1271
1272 list_add(&list_node->node, &md->maps);
1273
1274 return 0;
1275 }
1276
remove_old_maps(struct map * map,void * data)1277 static bool remove_old_maps(struct map *map, void *data)
1278 {
1279 const struct map *map_to_save = data;
1280
1281 /*
1282 * We need to preserve eBPF maps even if they are covered by kcore,
1283 * because we need to access eBPF dso for source data.
1284 */
1285 return !RC_CHK_EQUAL(map, map_to_save) && !__map__is_bpf_prog(map);
1286 }
1287
dso__load_kcore(struct dso * dso,struct map * map,const char * kallsyms_filename)1288 static int dso__load_kcore(struct dso *dso, struct map *map,
1289 const char *kallsyms_filename)
1290 {
1291 struct maps *kmaps = map__kmaps(map);
1292 struct kcore_mapfn_data md;
1293 struct map *map_ref, *replacement_map = NULL;
1294 struct machine *machine;
1295 bool is_64_bit;
1296 int err, fd;
1297 char kcore_filename[PATH_MAX];
1298 u64 stext;
1299
1300 if (!kmaps)
1301 return -EINVAL;
1302
1303 machine = maps__machine(kmaps);
1304
1305 /* This function requires that the map is the kernel map */
1306 if (!__map__is_kernel(map))
1307 return -EINVAL;
1308
1309 if (!filename_from_kallsyms_filename(kcore_filename, "kcore",
1310 kallsyms_filename))
1311 return -EINVAL;
1312
1313 /* Modules and kernel must be present at their original addresses */
1314 if (validate_kcore_addresses(kallsyms_filename, map))
1315 return -EINVAL;
1316
1317 md.dso = dso;
1318 INIT_LIST_HEAD(&md.maps);
1319
1320 fd = open(kcore_filename, O_RDONLY);
1321 if (fd < 0) {
1322 pr_debug("Failed to open %s. Note /proc/kcore requires CAP_SYS_RAWIO capability to access.\n",
1323 kcore_filename);
1324 return -EINVAL;
1325 }
1326
1327 /* Read new maps into temporary lists */
1328 err = file__read_maps(fd, map__prot(map) & PROT_EXEC, kcore_mapfn, &md,
1329 &is_64_bit);
1330 if (err)
1331 goto out_err;
1332 dso__set_is_64_bit(dso, is_64_bit);
1333
1334 if (list_empty(&md.maps)) {
1335 err = -EINVAL;
1336 goto out_err;
1337 }
1338
1339 /* Remove old maps */
1340 maps__remove_maps(kmaps, remove_old_maps, map);
1341 machine->trampolines_mapped = false;
1342
1343 /* Find the kernel map using the '_stext' symbol */
1344 if (!kallsyms__get_function_start(kallsyms_filename, "_stext", &stext)) {
1345 u64 replacement_size = 0;
1346 struct map_list_node *new_node;
1347
1348 list_for_each_entry(new_node, &md.maps, node) {
1349 struct map *new_map = new_node->map;
1350 u64 new_size = map__size(new_map);
1351
1352 if (!(stext >= map__start(new_map) && stext < map__end(new_map)))
1353 continue;
1354
1355 /*
1356 * On some architectures, ARM64 for example, the kernel
1357 * text can get allocated inside of the vmalloc segment.
1358 * Select the smallest matching segment, in case stext
1359 * falls within more than one in the list.
1360 */
1361 if (!replacement_map || new_size < replacement_size) {
1362 replacement_map = new_map;
1363 replacement_size = new_size;
1364 }
1365 }
1366 }
1367
1368 if (!replacement_map)
1369 replacement_map = list_entry(md.maps.next, struct map_list_node, node)->map;
1370
1371 /*
1372 * Update addresses of vmlinux map. Re-insert it to ensure maps are
1373 * correctly ordered. Do this before using maps__merge_in() for the
1374 * remaining maps so vmlinux gets split if necessary.
1375 */
1376 map_ref = map__get(map);
1377 maps__remove(kmaps, map_ref);
1378
1379 map__set_start(map_ref, map__start(replacement_map));
1380 map__set_end(map_ref, map__end(replacement_map));
1381 map__set_pgoff(map_ref, map__pgoff(replacement_map));
1382 map__set_mapping_type(map_ref, map__mapping_type(replacement_map));
1383
1384 err = maps__insert(kmaps, map_ref);
1385 map__put(map_ref);
1386 if (err)
1387 goto out_err;
1388
1389 /* Add new maps */
1390 while (!list_empty(&md.maps)) {
1391 struct map_list_node *new_node = list_entry(md.maps.next, struct map_list_node, node);
1392 struct map *new_map = new_node->map;
1393
1394 list_del_init(&new_node->node);
1395
1396 /* skip if replacement_map, already inserted above */
1397 if (!RC_CHK_EQUAL(new_map, replacement_map)) {
1398 /*
1399 * Merge kcore map into existing maps,
1400 * and ensure that current maps (eBPF)
1401 * stay intact.
1402 */
1403 if (maps__merge_in(kmaps, new_map)) {
1404 err = -EINVAL;
1405 goto out_err;
1406 }
1407 }
1408 free(new_node);
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) == DSO_SPACE__KERNEL_GUEST)
1429 dso__set_binary_type(dso, DSO_BINARY_TYPE__GUEST_KCORE);
1430 else
1431 dso__set_binary_type(dso, DSO_BINARY_TYPE__KCORE);
1432 dso__set_long_name(dso, strdup(kcore_filename), true);
1433
1434 close(fd);
1435
1436 if (map__prot(map) & 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 struct map_list_node *list_node;
1446
1447 list_node = list_entry(md.maps.next, struct map_list_node, node);
1448 list_del_init(&list_node->node);
1449 map__zput(list_node->map);
1450 free(list_node);
1451 }
1452 close(fd);
1453 return err;
1454 }
1455
1456 /*
1457 * If the kernel is relocated at boot time, kallsyms won't match. Compute the
1458 * delta based on the relocation reference symbol.
1459 */
kallsyms__delta(struct kmap * kmap,const char * filename,u64 * delta)1460 static int kallsyms__delta(struct kmap *kmap, const char *filename, u64 *delta)
1461 {
1462 u64 addr;
1463
1464 if (!kmap->ref_reloc_sym || !kmap->ref_reloc_sym->name)
1465 return 0;
1466
1467 if (kallsyms__get_function_start(filename, kmap->ref_reloc_sym->name, &addr))
1468 return -1;
1469
1470 *delta = addr - kmap->ref_reloc_sym->addr;
1471 return 0;
1472 }
1473
__dso__load_kallsyms(struct dso * dso,const char * filename,struct map * map,bool no_kcore)1474 int __dso__load_kallsyms(struct dso *dso, const char *filename,
1475 struct map *map, bool no_kcore)
1476 {
1477 struct kmap *kmap = map__kmap(map);
1478 u64 delta = 0;
1479
1480 if (symbol__restricted_filename(filename, "/proc/kallsyms"))
1481 return -1;
1482
1483 if (!kmap || !kmap->kmaps)
1484 return -1;
1485
1486 if (dso__load_all_kallsyms(dso, filename) < 0)
1487 return -1;
1488
1489 if (kallsyms__delta(kmap, filename, &delta))
1490 return -1;
1491
1492 symbols__fixup_end(dso__symbols(dso), true);
1493 symbols__fixup_duplicate(dso__symbols(dso));
1494
1495 if (dso__kernel(dso) == DSO_SPACE__KERNEL_GUEST)
1496 dso__set_symtab_type(dso, DSO_BINARY_TYPE__GUEST_KALLSYMS);
1497 else
1498 dso__set_symtab_type(dso, DSO_BINARY_TYPE__KALLSYMS);
1499
1500 if (!no_kcore && !dso__load_kcore(dso, map, filename))
1501 return maps__split_kallsyms_for_kcore(kmap->kmaps, dso);
1502 else
1503 return maps__split_kallsyms(kmap->kmaps, dso, delta, map);
1504 }
1505
dso__load_kallsyms(struct dso * dso,const char * filename,struct map * map)1506 int dso__load_kallsyms(struct dso *dso, const char *filename,
1507 struct map *map)
1508 {
1509 return __dso__load_kallsyms(dso, filename, map, false);
1510 }
1511
dso__load_perf_map(const char * map_path,struct dso * dso)1512 static int dso__load_perf_map(const char *map_path, struct dso *dso)
1513 {
1514 char *line = NULL;
1515 size_t n;
1516 FILE *file;
1517 int nr_syms = 0;
1518
1519 file = fopen(map_path, "r");
1520 if (file == NULL)
1521 goto out_failure;
1522
1523 while (!feof(file)) {
1524 u64 start, size;
1525 struct symbol *sym;
1526 int line_len, len;
1527
1528 line_len = getline(&line, &n, file);
1529 if (line_len < 0)
1530 break;
1531
1532 if (!line)
1533 goto out_failure;
1534
1535 line[--line_len] = '\0'; /* \n */
1536
1537 len = hex2u64(line, &start);
1538
1539 len++;
1540 if (len + 2 >= line_len)
1541 continue;
1542
1543 len += hex2u64(line + len, &size);
1544
1545 len++;
1546 if (len + 2 >= line_len)
1547 continue;
1548
1549 sym = symbol__new(start, size, STB_GLOBAL, STT_FUNC, line + len);
1550
1551 if (sym == NULL)
1552 goto out_delete_line;
1553
1554 symbols__insert(dso__symbols(dso), sym);
1555 nr_syms++;
1556 }
1557
1558 free(line);
1559 fclose(file);
1560
1561 return nr_syms;
1562
1563 out_delete_line:
1564 free(line);
1565 out_failure:
1566 return -1;
1567 }
1568
1569 #ifdef HAVE_LIBBFD_SUPPORT
1570 #define PACKAGE 'perf'
1571 #include <bfd.h>
1572
bfd_symbols__cmpvalue(const void * a,const void * b)1573 static int bfd_symbols__cmpvalue(const void *a, const void *b)
1574 {
1575 const asymbol *as = *(const asymbol **)a, *bs = *(const asymbol **)b;
1576
1577 if (bfd_asymbol_value(as) != bfd_asymbol_value(bs))
1578 return bfd_asymbol_value(as) - bfd_asymbol_value(bs);
1579
1580 return bfd_asymbol_name(as)[0] - bfd_asymbol_name(bs)[0];
1581 }
1582
bfd2elf_binding(asymbol * symbol)1583 static int bfd2elf_binding(asymbol *symbol)
1584 {
1585 if (symbol->flags & BSF_WEAK)
1586 return STB_WEAK;
1587 if (symbol->flags & BSF_GLOBAL)
1588 return STB_GLOBAL;
1589 if (symbol->flags & BSF_LOCAL)
1590 return STB_LOCAL;
1591 return -1;
1592 }
1593
dso__load_bfd_symbols(struct dso * dso,const char * debugfile)1594 int dso__load_bfd_symbols(struct dso *dso, const char *debugfile)
1595 {
1596 int err = -1;
1597 long symbols_size, symbols_count, i;
1598 asection *section;
1599 asymbol **symbols, *sym;
1600 struct symbol *symbol;
1601 bfd *abfd;
1602 u64 start, len;
1603
1604 abfd = bfd_openr(debugfile, NULL);
1605 if (!abfd)
1606 return -1;
1607
1608 if (!bfd_check_format(abfd, bfd_object)) {
1609 pr_debug2("%s: cannot read %s bfd file.\n", __func__,
1610 dso__long_name(dso));
1611 goto out_close;
1612 }
1613
1614 if (bfd_get_flavour(abfd) == bfd_target_elf_flavour)
1615 goto out_close;
1616
1617 symbols_size = bfd_get_symtab_upper_bound(abfd);
1618 if (symbols_size == 0) {
1619 bfd_close(abfd);
1620 return 0;
1621 }
1622
1623 if (symbols_size < 0)
1624 goto out_close;
1625
1626 symbols = malloc(symbols_size);
1627 if (!symbols)
1628 goto out_close;
1629
1630 symbols_count = bfd_canonicalize_symtab(abfd, symbols);
1631 if (symbols_count < 0)
1632 goto out_free;
1633
1634 section = bfd_get_section_by_name(abfd, ".text");
1635 if (section) {
1636 for (i = 0; i < symbols_count; ++i) {
1637 if (!strcmp(bfd_asymbol_name(symbols[i]), "__ImageBase") ||
1638 !strcmp(bfd_asymbol_name(symbols[i]), "__image_base__"))
1639 break;
1640 }
1641 if (i < symbols_count) {
1642 /* PE symbols can only have 4 bytes, so use .text high bits */
1643 u64 text_offset = (section->vma - (u32)section->vma)
1644 + (u32)bfd_asymbol_value(symbols[i]);
1645 dso__set_text_offset(dso, text_offset);
1646 dso__set_text_end(dso, (section->vma - text_offset) + section->size);
1647 } else {
1648 dso__set_text_offset(dso, section->vma - section->filepos);
1649 dso__set_text_end(dso, section->filepos + section->size);
1650 }
1651 }
1652
1653 qsort(symbols, symbols_count, sizeof(asymbol *), bfd_symbols__cmpvalue);
1654
1655 #ifdef bfd_get_section
1656 #define bfd_asymbol_section bfd_get_section
1657 #endif
1658 for (i = 0; i < symbols_count; ++i) {
1659 sym = symbols[i];
1660 section = bfd_asymbol_section(sym);
1661 if (bfd2elf_binding(sym) < 0)
1662 continue;
1663
1664 while (i + 1 < symbols_count &&
1665 bfd_asymbol_section(symbols[i + 1]) == section &&
1666 bfd2elf_binding(symbols[i + 1]) < 0)
1667 i++;
1668
1669 if (i + 1 < symbols_count &&
1670 bfd_asymbol_section(symbols[i + 1]) == section)
1671 len = symbols[i + 1]->value - sym->value;
1672 else
1673 len = section->size - sym->value;
1674
1675 start = bfd_asymbol_value(sym) - dso__text_offset(dso);
1676 symbol = symbol__new(start, len, bfd2elf_binding(sym), STT_FUNC,
1677 bfd_asymbol_name(sym));
1678 if (!symbol)
1679 goto out_free;
1680
1681 symbols__insert(dso__symbols(dso), symbol);
1682 }
1683 #ifdef bfd_get_section
1684 #undef bfd_asymbol_section
1685 #endif
1686
1687 symbols__fixup_end(dso__symbols(dso), false);
1688 symbols__fixup_duplicate(dso__symbols(dso));
1689 dso__set_adjust_symbols(dso, true);
1690
1691 err = 0;
1692 out_free:
1693 free(symbols);
1694 out_close:
1695 bfd_close(abfd);
1696 return err;
1697 }
1698 #endif
1699
dso__is_compatible_symtab_type(struct dso * dso,bool kmod,enum dso_binary_type type)1700 static bool dso__is_compatible_symtab_type(struct dso *dso, bool kmod,
1701 enum dso_binary_type type)
1702 {
1703 switch (type) {
1704 case DSO_BINARY_TYPE__JAVA_JIT:
1705 case DSO_BINARY_TYPE__DEBUGLINK:
1706 case DSO_BINARY_TYPE__SYSTEM_PATH_DSO:
1707 case DSO_BINARY_TYPE__FEDORA_DEBUGINFO:
1708 case DSO_BINARY_TYPE__UBUNTU_DEBUGINFO:
1709 case DSO_BINARY_TYPE__MIXEDUP_UBUNTU_DEBUGINFO:
1710 case DSO_BINARY_TYPE__BUILDID_DEBUGINFO:
1711 case DSO_BINARY_TYPE__OPENEMBEDDED_DEBUGINFO:
1712 return !kmod && dso__kernel(dso) == DSO_SPACE__USER;
1713
1714 case DSO_BINARY_TYPE__KALLSYMS:
1715 case DSO_BINARY_TYPE__VMLINUX:
1716 case DSO_BINARY_TYPE__KCORE:
1717 return dso__kernel(dso) == DSO_SPACE__KERNEL;
1718
1719 case DSO_BINARY_TYPE__GUEST_KALLSYMS:
1720 case DSO_BINARY_TYPE__GUEST_VMLINUX:
1721 case DSO_BINARY_TYPE__GUEST_KCORE:
1722 return dso__kernel(dso) == DSO_SPACE__KERNEL_GUEST;
1723
1724 case DSO_BINARY_TYPE__GUEST_KMODULE:
1725 case DSO_BINARY_TYPE__GUEST_KMODULE_COMP:
1726 case DSO_BINARY_TYPE__SYSTEM_PATH_KMODULE:
1727 case DSO_BINARY_TYPE__SYSTEM_PATH_KMODULE_COMP:
1728 /*
1729 * kernel modules know their symtab type - it's set when
1730 * creating a module dso in machine__addnew_module_map().
1731 */
1732 return kmod && dso__symtab_type(dso) == type;
1733
1734 case DSO_BINARY_TYPE__BUILD_ID_CACHE:
1735 case DSO_BINARY_TYPE__BUILD_ID_CACHE_DEBUGINFO:
1736 return true;
1737
1738 case DSO_BINARY_TYPE__BPF_PROG_INFO:
1739 case DSO_BINARY_TYPE__BPF_IMAGE:
1740 case DSO_BINARY_TYPE__OOL:
1741 case DSO_BINARY_TYPE__NOT_FOUND:
1742 default:
1743 return false;
1744 }
1745 }
1746
1747 /* Checks for the existence of the perf-<pid>.map file in two different
1748 * locations. First, if the process is a separate mount namespace, check in
1749 * that namespace using the pid of the innermost pid namespace. If's not in a
1750 * namespace, or the file can't be found there, try in the mount namespace of
1751 * the tracing process using our view of its pid.
1752 */
dso__find_perf_map(char * filebuf,size_t bufsz,struct nsinfo ** nsip)1753 static int dso__find_perf_map(char *filebuf, size_t bufsz,
1754 struct nsinfo **nsip)
1755 {
1756 struct nscookie nsc;
1757 struct nsinfo *nsi;
1758 struct nsinfo *nnsi;
1759 int rc = -1;
1760
1761 nsi = *nsip;
1762
1763 if (nsinfo__need_setns(nsi)) {
1764 snprintf(filebuf, bufsz, "/tmp/perf-%d.map", nsinfo__nstgid(nsi));
1765 nsinfo__mountns_enter(nsi, &nsc);
1766 rc = access(filebuf, R_OK);
1767 nsinfo__mountns_exit(&nsc);
1768 if (rc == 0)
1769 return rc;
1770 }
1771
1772 nnsi = nsinfo__copy(nsi);
1773 if (nnsi) {
1774 nsinfo__put(nsi);
1775
1776 nsinfo__clear_need_setns(nnsi);
1777 snprintf(filebuf, bufsz, "/tmp/perf-%d.map", nsinfo__tgid(nnsi));
1778 *nsip = nnsi;
1779 rc = 0;
1780 }
1781
1782 return rc;
1783 }
1784
dso__load(struct dso * dso,struct map * map)1785 int dso__load(struct dso *dso, struct map *map)
1786 {
1787 char *name;
1788 int ret = -1;
1789 u_int i;
1790 struct machine *machine = NULL;
1791 char *root_dir = (char *) "";
1792 int ss_pos = 0;
1793 struct symsrc ss_[2];
1794 struct symsrc *syms_ss = NULL, *runtime_ss = NULL;
1795 bool kmod;
1796 bool perfmap;
1797 struct build_id bid;
1798 struct nscookie nsc;
1799 char newmapname[PATH_MAX];
1800 const char *map_path = dso__long_name(dso);
1801
1802 mutex_lock(dso__lock(dso));
1803 perfmap = is_perf_pid_map_name(map_path);
1804
1805 if (perfmap) {
1806 if (dso__nsinfo(dso) &&
1807 (dso__find_perf_map(newmapname, sizeof(newmapname),
1808 dso__nsinfo_ptr(dso)) == 0)) {
1809 map_path = newmapname;
1810 }
1811 }
1812
1813 nsinfo__mountns_enter(dso__nsinfo(dso), &nsc);
1814
1815 /* check again under the dso->lock */
1816 if (dso__loaded(dso)) {
1817 ret = 1;
1818 goto out;
1819 }
1820
1821 kmod = dso__is_kmod(dso);
1822
1823 if (dso__kernel(dso) && !kmod) {
1824 if (dso__kernel(dso) == DSO_SPACE__KERNEL)
1825 ret = dso__load_kernel_sym(dso, map);
1826 else if (dso__kernel(dso) == DSO_SPACE__KERNEL_GUEST)
1827 ret = dso__load_guest_kernel_sym(dso, map);
1828
1829 machine = maps__machine(map__kmaps(map));
1830 if (machine__is(machine, "x86_64"))
1831 machine__map_x86_64_entry_trampolines(machine, dso);
1832 goto out;
1833 }
1834
1835 dso__set_adjust_symbols(dso, false);
1836
1837 if (perfmap) {
1838 ret = dso__load_perf_map(map_path, dso);
1839 dso__set_symtab_type(dso, ret > 0
1840 ? DSO_BINARY_TYPE__JAVA_JIT
1841 : DSO_BINARY_TYPE__NOT_FOUND);
1842 goto out;
1843 }
1844
1845 if (machine)
1846 root_dir = machine->root_dir;
1847
1848 name = malloc(PATH_MAX);
1849 if (!name)
1850 goto out;
1851
1852 /*
1853 * Read the build id if possible. This is required for
1854 * DSO_BINARY_TYPE__BUILDID_DEBUGINFO to work
1855 */
1856 if (!dso__has_build_id(dso) &&
1857 is_regular_file(dso__long_name(dso))) {
1858 __symbol__join_symfs(name, PATH_MAX, dso__long_name(dso));
1859 if (filename__read_build_id(name, &bid) > 0)
1860 dso__set_build_id(dso, &bid);
1861 }
1862
1863 /*
1864 * Iterate over candidate debug images.
1865 * Keep track of "interesting" ones (those which have a symtab, dynsym,
1866 * and/or opd section) for processing.
1867 */
1868 for (i = 0; i < DSO_BINARY_TYPE__SYMTAB_CNT; i++) {
1869 struct symsrc *ss = &ss_[ss_pos];
1870 bool next_slot = false;
1871 bool is_reg;
1872 bool nsexit;
1873 int bfdrc = -1;
1874 int sirc = -1;
1875
1876 enum dso_binary_type symtab_type = binary_type_symtab[i];
1877
1878 nsexit = (symtab_type == DSO_BINARY_TYPE__BUILD_ID_CACHE ||
1879 symtab_type == DSO_BINARY_TYPE__BUILD_ID_CACHE_DEBUGINFO);
1880
1881 if (!dso__is_compatible_symtab_type(dso, kmod, symtab_type))
1882 continue;
1883
1884 if (dso__read_binary_type_filename(dso, symtab_type,
1885 root_dir, name, PATH_MAX))
1886 continue;
1887
1888 if (nsexit)
1889 nsinfo__mountns_exit(&nsc);
1890
1891 is_reg = is_regular_file(name);
1892 if (!is_reg && errno == ENOENT && dso__nsinfo(dso)) {
1893 char *new_name = dso__filename_with_chroot(dso, name);
1894 if (new_name) {
1895 is_reg = is_regular_file(new_name);
1896 strlcpy(name, new_name, PATH_MAX);
1897 free(new_name);
1898 }
1899 }
1900
1901 #ifdef HAVE_LIBBFD_SUPPORT
1902 if (is_reg)
1903 bfdrc = dso__load_bfd_symbols(dso, name);
1904 #endif
1905 if (is_reg && bfdrc < 0)
1906 sirc = symsrc__init(ss, dso, name, symtab_type);
1907
1908 if (nsexit)
1909 nsinfo__mountns_enter(dso__nsinfo(dso), &nsc);
1910
1911 if (bfdrc == 0) {
1912 ret = 0;
1913 break;
1914 }
1915
1916 if (!is_reg || sirc < 0)
1917 continue;
1918
1919 if (!syms_ss && symsrc__has_symtab(ss)) {
1920 syms_ss = ss;
1921 next_slot = true;
1922 if (!dso__symsrc_filename(dso))
1923 dso__set_symsrc_filename(dso, strdup(name));
1924 }
1925
1926 if (!runtime_ss && symsrc__possibly_runtime(ss)) {
1927 runtime_ss = ss;
1928 next_slot = true;
1929 }
1930
1931 if (next_slot) {
1932 ss_pos++;
1933
1934 if (syms_ss && runtime_ss)
1935 break;
1936 } else {
1937 symsrc__destroy(ss);
1938 }
1939
1940 }
1941
1942 if (!runtime_ss && !syms_ss)
1943 goto out_free;
1944
1945 if (runtime_ss && !syms_ss) {
1946 syms_ss = runtime_ss;
1947 }
1948
1949 /* We'll have to hope for the best */
1950 if (!runtime_ss && syms_ss)
1951 runtime_ss = syms_ss;
1952
1953 if (syms_ss)
1954 ret = dso__load_sym(dso, map, syms_ss, runtime_ss, kmod);
1955 else
1956 ret = -1;
1957
1958 if (ret > 0) {
1959 int nr_plt;
1960
1961 nr_plt = dso__synthesize_plt_symbols(dso, runtime_ss);
1962 if (nr_plt > 0)
1963 ret += nr_plt;
1964 }
1965
1966 for (; ss_pos > 0; ss_pos--)
1967 symsrc__destroy(&ss_[ss_pos - 1]);
1968 out_free:
1969 free(name);
1970 if (ret < 0 && strstr(dso__name(dso), " (deleted)") != NULL)
1971 ret = 0;
1972 out:
1973 dso__set_loaded(dso);
1974 mutex_unlock(dso__lock(dso));
1975 nsinfo__mountns_exit(&nsc);
1976
1977 return ret;
1978 }
1979
1980 /*
1981 * Always takes ownership of vmlinux when vmlinux_allocated == true, even if
1982 * it returns an error.
1983 */
dso__load_vmlinux(struct dso * dso,struct map * map,const char * vmlinux,bool vmlinux_allocated)1984 int dso__load_vmlinux(struct dso *dso, struct map *map,
1985 const char *vmlinux, bool vmlinux_allocated)
1986 {
1987 int err = -1;
1988 struct symsrc ss;
1989 char symfs_vmlinux[PATH_MAX];
1990 enum dso_binary_type symtab_type;
1991
1992 if (vmlinux[0] == '/')
1993 snprintf(symfs_vmlinux, sizeof(symfs_vmlinux), "%s", vmlinux);
1994 else
1995 symbol__join_symfs(symfs_vmlinux, vmlinux);
1996
1997 if (dso__kernel(dso) == DSO_SPACE__KERNEL_GUEST)
1998 symtab_type = DSO_BINARY_TYPE__GUEST_VMLINUX;
1999 else
2000 symtab_type = DSO_BINARY_TYPE__VMLINUX;
2001
2002 if (symsrc__init(&ss, dso, symfs_vmlinux, symtab_type)) {
2003 if (vmlinux_allocated)
2004 free((char *) vmlinux);
2005 return -1;
2006 }
2007
2008 /*
2009 * dso__load_sym() may copy 'dso' which will result in the copies having
2010 * an incorrect long name unless we set it here first.
2011 */
2012 dso__set_long_name(dso, vmlinux, vmlinux_allocated);
2013 if (dso__kernel(dso) == DSO_SPACE__KERNEL_GUEST)
2014 dso__set_binary_type(dso, DSO_BINARY_TYPE__GUEST_VMLINUX);
2015 else
2016 dso__set_binary_type(dso, DSO_BINARY_TYPE__VMLINUX);
2017
2018 err = dso__load_sym(dso, map, &ss, &ss, 0);
2019 symsrc__destroy(&ss);
2020
2021 if (err > 0) {
2022 dso__set_loaded(dso);
2023 pr_debug("Using %s for symbols\n", symfs_vmlinux);
2024 }
2025
2026 return err;
2027 }
2028
dso__load_vmlinux_path(struct dso * dso,struct map * map)2029 int dso__load_vmlinux_path(struct dso *dso, struct map *map)
2030 {
2031 int i, err = 0;
2032 char *filename = NULL;
2033
2034 pr_debug("Looking at the vmlinux_path (%d entries long)\n",
2035 vmlinux_path__nr_entries + 1);
2036
2037 for (i = 0; i < vmlinux_path__nr_entries; ++i) {
2038 err = dso__load_vmlinux(dso, map, vmlinux_path[i], false);
2039 if (err > 0)
2040 goto out;
2041 }
2042
2043 if (!symbol_conf.ignore_vmlinux_buildid)
2044 filename = dso__build_id_filename(dso, NULL, 0, false);
2045 if (filename != NULL) {
2046 err = dso__load_vmlinux(dso, map, filename, true);
2047 if (err > 0)
2048 goto out;
2049 }
2050 out:
2051 return err;
2052 }
2053
visible_dir_filter(const char * name,struct dirent * d)2054 static bool visible_dir_filter(const char *name, struct dirent *d)
2055 {
2056 if (d->d_type != DT_DIR)
2057 return false;
2058 return lsdir_no_dot_filter(name, d);
2059 }
2060
find_matching_kcore(struct map * map,char * dir,size_t dir_sz)2061 static int find_matching_kcore(struct map *map, char *dir, size_t dir_sz)
2062 {
2063 char kallsyms_filename[PATH_MAX];
2064 int ret = -1;
2065 struct strlist *dirs;
2066 struct str_node *nd;
2067
2068 dirs = lsdir(dir, visible_dir_filter);
2069 if (!dirs)
2070 return -1;
2071
2072 strlist__for_each_entry(nd, dirs) {
2073 scnprintf(kallsyms_filename, sizeof(kallsyms_filename),
2074 "%s/%s/kallsyms", dir, nd->s);
2075 if (!validate_kcore_addresses(kallsyms_filename, map)) {
2076 strlcpy(dir, kallsyms_filename, dir_sz);
2077 ret = 0;
2078 break;
2079 }
2080 }
2081
2082 strlist__delete(dirs);
2083
2084 return ret;
2085 }
2086
2087 /*
2088 * Use open(O_RDONLY) to check readability directly instead of access(R_OK)
2089 * since access(R_OK) only checks with real UID/GID but open() use effective
2090 * UID/GID and actual capabilities (e.g. /proc/kcore requires CAP_SYS_RAWIO).
2091 */
filename__readable(const char * file)2092 static bool filename__readable(const char *file)
2093 {
2094 int fd = open(file, O_RDONLY);
2095 if (fd < 0)
2096 return false;
2097 close(fd);
2098 return true;
2099 }
2100
dso__find_kallsyms(struct dso * dso,struct map * map)2101 static char *dso__find_kallsyms(struct dso *dso, struct map *map)
2102 {
2103 struct build_id bid;
2104 char sbuild_id[SBUILD_ID_SIZE];
2105 bool is_host = false;
2106 char path[PATH_MAX];
2107
2108 if (!dso__has_build_id(dso)) {
2109 /*
2110 * Last resort, if we don't have a build-id and couldn't find
2111 * any vmlinux file, try the running kernel kallsyms table.
2112 */
2113 goto proc_kallsyms;
2114 }
2115
2116 if (sysfs__read_build_id("/sys/kernel/notes", &bid) == 0)
2117 is_host = dso__build_id_equal(dso, &bid);
2118
2119 /* Try a fast path for /proc/kallsyms if possible */
2120 if (is_host) {
2121 /*
2122 * Do not check the build-id cache, unless we know we cannot use
2123 * /proc/kcore or module maps don't match to /proc/kallsyms.
2124 * To check readability of /proc/kcore, do not use access(R_OK)
2125 * since /proc/kcore requires CAP_SYS_RAWIO to read and access
2126 * can't check it.
2127 */
2128 if (filename__readable("/proc/kcore") &&
2129 !validate_kcore_addresses("/proc/kallsyms", map))
2130 goto proc_kallsyms;
2131 }
2132
2133 build_id__sprintf(dso__bid(dso), sbuild_id);
2134
2135 /* Find kallsyms in build-id cache with kcore */
2136 scnprintf(path, sizeof(path), "%s/%s/%s",
2137 buildid_dir, DSO__NAME_KCORE, sbuild_id);
2138
2139 if (!find_matching_kcore(map, path, sizeof(path)))
2140 return strdup(path);
2141
2142 /* Use current /proc/kallsyms if possible */
2143 if (is_host) {
2144 proc_kallsyms:
2145 return strdup("/proc/kallsyms");
2146 }
2147
2148 /* Finally, find a cache of kallsyms */
2149 if (!build_id_cache__kallsyms_path(sbuild_id, path, sizeof(path))) {
2150 pr_err("No kallsyms or vmlinux with build-id %s was found\n",
2151 sbuild_id);
2152 return NULL;
2153 }
2154
2155 return strdup(path);
2156 }
2157
dso__load_kernel_sym(struct dso * dso,struct map * map)2158 static int dso__load_kernel_sym(struct dso *dso, struct map *map)
2159 {
2160 int err;
2161 const char *kallsyms_filename = NULL;
2162 char *kallsyms_allocated_filename = NULL;
2163 char *filename = NULL;
2164
2165 /*
2166 * Step 1: if the user specified a kallsyms or vmlinux filename, use
2167 * it and only it, reporting errors to the user if it cannot be used.
2168 *
2169 * For instance, try to analyse an ARM perf.data file _without_ a
2170 * build-id, or if the user specifies the wrong path to the right
2171 * vmlinux file, obviously we can't fallback to another vmlinux (a
2172 * x86_86 one, on the machine where analysis is being performed, say),
2173 * or worse, /proc/kallsyms.
2174 *
2175 * If the specified file _has_ a build-id and there is a build-id
2176 * section in the perf.data file, we will still do the expected
2177 * validation in dso__load_vmlinux and will bail out if they don't
2178 * match.
2179 */
2180 if (symbol_conf.kallsyms_name != NULL) {
2181 kallsyms_filename = symbol_conf.kallsyms_name;
2182 goto do_kallsyms;
2183 }
2184
2185 if (!symbol_conf.ignore_vmlinux && symbol_conf.vmlinux_name != NULL) {
2186 return dso__load_vmlinux(dso, map, symbol_conf.vmlinux_name, false);
2187 }
2188
2189 /*
2190 * Before checking on common vmlinux locations, check if it's
2191 * stored as standard build id binary (not kallsyms) under
2192 * .debug cache.
2193 */
2194 if (!symbol_conf.ignore_vmlinux_buildid)
2195 filename = __dso__build_id_filename(dso, NULL, 0, false, false);
2196 if (filename != NULL) {
2197 err = dso__load_vmlinux(dso, map, filename, true);
2198 if (err > 0)
2199 return err;
2200 }
2201
2202 if (!symbol_conf.ignore_vmlinux && vmlinux_path != NULL) {
2203 err = dso__load_vmlinux_path(dso, map);
2204 if (err > 0)
2205 return err;
2206 }
2207
2208 /* do not try local files if a symfs was given */
2209 if (symbol_conf.symfs[0] != 0)
2210 return -1;
2211
2212 kallsyms_allocated_filename = dso__find_kallsyms(dso, map);
2213 if (!kallsyms_allocated_filename)
2214 return -1;
2215
2216 kallsyms_filename = kallsyms_allocated_filename;
2217
2218 do_kallsyms:
2219 err = dso__load_kallsyms(dso, kallsyms_filename, map);
2220 if (err > 0)
2221 pr_debug("Using %s for symbols\n", kallsyms_filename);
2222 free(kallsyms_allocated_filename);
2223
2224 if (err > 0 && !dso__is_kcore(dso)) {
2225 dso__set_binary_type(dso, DSO_BINARY_TYPE__KALLSYMS);
2226 dso__set_long_name(dso, DSO__NAME_KALLSYMS, false);
2227 map__fixup_start(map);
2228 map__fixup_end(map);
2229 }
2230
2231 return err;
2232 }
2233
dso__load_guest_kernel_sym(struct dso * dso,struct map * map)2234 static int dso__load_guest_kernel_sym(struct dso *dso, struct map *map)
2235 {
2236 int err;
2237 const char *kallsyms_filename;
2238 struct machine *machine = maps__machine(map__kmaps(map));
2239 char path[PATH_MAX];
2240
2241 if (machine->kallsyms_filename) {
2242 kallsyms_filename = machine->kallsyms_filename;
2243 } else if (machine__is_default_guest(machine)) {
2244 /*
2245 * if the user specified a vmlinux filename, use it and only
2246 * it, reporting errors to the user if it cannot be used.
2247 * Or use file guest_kallsyms inputted by user on commandline
2248 */
2249 if (symbol_conf.default_guest_vmlinux_name != NULL) {
2250 err = dso__load_vmlinux(dso, map,
2251 symbol_conf.default_guest_vmlinux_name,
2252 false);
2253 return err;
2254 }
2255
2256 kallsyms_filename = symbol_conf.default_guest_kallsyms;
2257 if (!kallsyms_filename)
2258 return -1;
2259 } else {
2260 sprintf(path, "%s/proc/kallsyms", machine->root_dir);
2261 kallsyms_filename = path;
2262 }
2263
2264 err = dso__load_kallsyms(dso, kallsyms_filename, map);
2265 if (err > 0)
2266 pr_debug("Using %s for symbols\n", kallsyms_filename);
2267 if (err > 0 && !dso__is_kcore(dso)) {
2268 dso__set_binary_type(dso, DSO_BINARY_TYPE__GUEST_KALLSYMS);
2269 dso__set_long_name(dso, machine->mmap_name, false);
2270 map__fixup_start(map);
2271 map__fixup_end(map);
2272 }
2273
2274 return err;
2275 }
2276
vmlinux_path__exit(void)2277 static void vmlinux_path__exit(void)
2278 {
2279 while (--vmlinux_path__nr_entries >= 0)
2280 zfree(&vmlinux_path[vmlinux_path__nr_entries]);
2281 vmlinux_path__nr_entries = 0;
2282
2283 zfree(&vmlinux_path);
2284 }
2285
2286 static const char * const vmlinux_paths[] = {
2287 "vmlinux",
2288 "/boot/vmlinux"
2289 };
2290
2291 static const char * const vmlinux_paths_upd[] = {
2292 "/boot/vmlinux-%s",
2293 "/usr/lib/debug/boot/vmlinux-%s",
2294 "/lib/modules/%s/build/vmlinux",
2295 "/usr/lib/debug/lib/modules/%s/vmlinux",
2296 "/usr/lib/debug/boot/vmlinux-%s.debug"
2297 };
2298
vmlinux_path__add(const char * new_entry)2299 static int vmlinux_path__add(const char *new_entry)
2300 {
2301 vmlinux_path[vmlinux_path__nr_entries] = strdup(new_entry);
2302 if (vmlinux_path[vmlinux_path__nr_entries] == NULL)
2303 return -1;
2304 ++vmlinux_path__nr_entries;
2305
2306 return 0;
2307 }
2308
vmlinux_path__init(struct perf_env * env)2309 static int vmlinux_path__init(struct perf_env *env)
2310 {
2311 struct utsname uts;
2312 char bf[PATH_MAX];
2313 char *kernel_version;
2314 unsigned int i;
2315
2316 vmlinux_path = malloc(sizeof(char *) * (ARRAY_SIZE(vmlinux_paths) +
2317 ARRAY_SIZE(vmlinux_paths_upd)));
2318 if (vmlinux_path == NULL)
2319 return -1;
2320
2321 for (i = 0; i < ARRAY_SIZE(vmlinux_paths); i++)
2322 if (vmlinux_path__add(vmlinux_paths[i]) < 0)
2323 goto out_fail;
2324
2325 /* only try kernel version if no symfs was given */
2326 if (symbol_conf.symfs[0] != 0)
2327 return 0;
2328
2329 if (env) {
2330 kernel_version = env->os_release;
2331 } else {
2332 if (uname(&uts) < 0)
2333 goto out_fail;
2334
2335 kernel_version = uts.release;
2336 }
2337
2338 for (i = 0; i < ARRAY_SIZE(vmlinux_paths_upd); i++) {
2339 snprintf(bf, sizeof(bf), vmlinux_paths_upd[i], kernel_version);
2340 if (vmlinux_path__add(bf) < 0)
2341 goto out_fail;
2342 }
2343
2344 return 0;
2345
2346 out_fail:
2347 vmlinux_path__exit();
2348 return -1;
2349 }
2350
setup_list(struct strlist ** list,const char * list_str,const char * list_name)2351 int setup_list(struct strlist **list, const char *list_str,
2352 const char *list_name)
2353 {
2354 if (list_str == NULL)
2355 return 0;
2356
2357 *list = strlist__new(list_str, NULL);
2358 if (!*list) {
2359 pr_err("problems parsing %s list\n", list_name);
2360 return -1;
2361 }
2362
2363 symbol_conf.has_filter = true;
2364 return 0;
2365 }
2366
setup_intlist(struct intlist ** list,const char * list_str,const char * list_name)2367 int setup_intlist(struct intlist **list, const char *list_str,
2368 const char *list_name)
2369 {
2370 if (list_str == NULL)
2371 return 0;
2372
2373 *list = intlist__new(list_str);
2374 if (!*list) {
2375 pr_err("problems parsing %s list\n", list_name);
2376 return -1;
2377 }
2378 return 0;
2379 }
2380
setup_addrlist(struct intlist ** addr_list,struct strlist * sym_list)2381 static int setup_addrlist(struct intlist **addr_list, struct strlist *sym_list)
2382 {
2383 struct str_node *pos, *tmp;
2384 unsigned long val;
2385 char *sep;
2386 const char *end;
2387 int i = 0, err;
2388
2389 *addr_list = intlist__new(NULL);
2390 if (!*addr_list)
2391 return -1;
2392
2393 strlist__for_each_entry_safe(pos, tmp, sym_list) {
2394 errno = 0;
2395 val = strtoul(pos->s, &sep, 16);
2396 if (errno || (sep == pos->s))
2397 continue;
2398
2399 if (*sep != '\0') {
2400 end = pos->s + strlen(pos->s) - 1;
2401 while (end >= sep && isspace(*end))
2402 end--;
2403
2404 if (end >= sep)
2405 continue;
2406 }
2407
2408 err = intlist__add(*addr_list, val);
2409 if (err)
2410 break;
2411
2412 strlist__remove(sym_list, pos);
2413 i++;
2414 }
2415
2416 if (i == 0) {
2417 intlist__delete(*addr_list);
2418 *addr_list = NULL;
2419 }
2420
2421 return 0;
2422 }
2423
symbol__read_kptr_restrict(void)2424 static bool symbol__read_kptr_restrict(void)
2425 {
2426 bool value = false;
2427 FILE *fp = fopen("/proc/sys/kernel/kptr_restrict", "r");
2428
2429 if (fp != NULL) {
2430 char line[8];
2431
2432 if (fgets(line, sizeof(line), fp) != NULL)
2433 value = perf_cap__capable(CAP_SYSLOG) ?
2434 (atoi(line) >= 2) :
2435 (atoi(line) != 0);
2436
2437 fclose(fp);
2438 }
2439
2440 /* Per kernel/kallsyms.c:
2441 * we also restrict when perf_event_paranoid > 1 w/o CAP_SYSLOG
2442 */
2443 if (perf_event_paranoid() > 1 && !perf_cap__capable(CAP_SYSLOG))
2444 value = true;
2445
2446 return value;
2447 }
2448
symbol__annotation_init(void)2449 int symbol__annotation_init(void)
2450 {
2451 if (symbol_conf.init_annotation)
2452 return 0;
2453
2454 if (symbol_conf.initialized) {
2455 pr_err("Annotation needs to be init before symbol__init()\n");
2456 return -1;
2457 }
2458
2459 symbol_conf.priv_size += sizeof(struct annotation);
2460 symbol_conf.init_annotation = true;
2461 return 0;
2462 }
2463
symbol__init(struct perf_env * env)2464 int symbol__init(struct perf_env *env)
2465 {
2466 const char *symfs;
2467
2468 if (symbol_conf.initialized)
2469 return 0;
2470
2471 symbol_conf.priv_size = PERF_ALIGN(symbol_conf.priv_size, sizeof(u64));
2472
2473 symbol__elf_init();
2474
2475 if (symbol_conf.try_vmlinux_path && vmlinux_path__init(env) < 0)
2476 return -1;
2477
2478 if (symbol_conf.field_sep && *symbol_conf.field_sep == '.') {
2479 pr_err("'.' is the only non valid --field-separator argument\n");
2480 return -1;
2481 }
2482
2483 if (setup_list(&symbol_conf.dso_list,
2484 symbol_conf.dso_list_str, "dso") < 0)
2485 return -1;
2486
2487 if (setup_list(&symbol_conf.comm_list,
2488 symbol_conf.comm_list_str, "comm") < 0)
2489 goto out_free_dso_list;
2490
2491 if (setup_intlist(&symbol_conf.pid_list,
2492 symbol_conf.pid_list_str, "pid") < 0)
2493 goto out_free_comm_list;
2494
2495 if (setup_intlist(&symbol_conf.tid_list,
2496 symbol_conf.tid_list_str, "tid") < 0)
2497 goto out_free_pid_list;
2498
2499 if (setup_list(&symbol_conf.sym_list,
2500 symbol_conf.sym_list_str, "symbol") < 0)
2501 goto out_free_tid_list;
2502
2503 if (symbol_conf.sym_list &&
2504 setup_addrlist(&symbol_conf.addr_list, symbol_conf.sym_list) < 0)
2505 goto out_free_sym_list;
2506
2507 if (setup_list(&symbol_conf.bt_stop_list,
2508 symbol_conf.bt_stop_list_str, "symbol") < 0)
2509 goto out_free_sym_list;
2510
2511 /*
2512 * A path to symbols of "/" is identical to ""
2513 * reset here for simplicity.
2514 */
2515 symfs = realpath(symbol_conf.symfs, NULL);
2516 if (symfs == NULL)
2517 symfs = symbol_conf.symfs;
2518 if (strcmp(symfs, "/") == 0)
2519 symbol_conf.symfs = "";
2520 if (symfs != symbol_conf.symfs)
2521 free((void *)symfs);
2522
2523 symbol_conf.kptr_restrict = symbol__read_kptr_restrict();
2524
2525 symbol_conf.initialized = true;
2526 return 0;
2527
2528 out_free_sym_list:
2529 strlist__delete(symbol_conf.sym_list);
2530 intlist__delete(symbol_conf.addr_list);
2531 out_free_tid_list:
2532 intlist__delete(symbol_conf.tid_list);
2533 out_free_pid_list:
2534 intlist__delete(symbol_conf.pid_list);
2535 out_free_comm_list:
2536 strlist__delete(symbol_conf.comm_list);
2537 out_free_dso_list:
2538 strlist__delete(symbol_conf.dso_list);
2539 return -1;
2540 }
2541
symbol__exit(void)2542 void symbol__exit(void)
2543 {
2544 if (!symbol_conf.initialized)
2545 return;
2546 strlist__delete(symbol_conf.bt_stop_list);
2547 strlist__delete(symbol_conf.sym_list);
2548 strlist__delete(symbol_conf.dso_list);
2549 strlist__delete(symbol_conf.comm_list);
2550 intlist__delete(symbol_conf.tid_list);
2551 intlist__delete(symbol_conf.pid_list);
2552 intlist__delete(symbol_conf.addr_list);
2553 vmlinux_path__exit();
2554 symbol_conf.sym_list = symbol_conf.dso_list = symbol_conf.comm_list = NULL;
2555 symbol_conf.bt_stop_list = NULL;
2556 symbol_conf.initialized = false;
2557 }
2558
symbol__config_symfs(const struct option * opt __maybe_unused,const char * dir,int unset __maybe_unused)2559 int symbol__config_symfs(const struct option *opt __maybe_unused,
2560 const char *dir, int unset __maybe_unused)
2561 {
2562 char *bf = NULL;
2563 int ret;
2564
2565 symbol_conf.symfs = strdup(dir);
2566 if (symbol_conf.symfs == NULL)
2567 return -ENOMEM;
2568
2569 /* skip the locally configured cache if a symfs is given, and
2570 * config buildid dir to symfs/.debug
2571 */
2572 ret = asprintf(&bf, "%s/%s", dir, ".debug");
2573 if (ret < 0)
2574 return -ENOMEM;
2575
2576 set_buildid_dir(bf);
2577
2578 free(bf);
2579 return 0;
2580 }
2581
2582 /*
2583 * Checks that user supplied symbol kernel files are accessible because
2584 * the default mechanism for accessing elf files fails silently. i.e. if
2585 * debug syms for a build ID aren't found perf carries on normally. When
2586 * they are user supplied we should assume that the user doesn't want to
2587 * silently fail.
2588 */
symbol__validate_sym_arguments(void)2589 int symbol__validate_sym_arguments(void)
2590 {
2591 if (symbol_conf.vmlinux_name &&
2592 access(symbol_conf.vmlinux_name, R_OK)) {
2593 pr_err("Invalid file: %s\n", symbol_conf.vmlinux_name);
2594 return -EINVAL;
2595 }
2596 if (symbol_conf.kallsyms_name &&
2597 access(symbol_conf.kallsyms_name, R_OK)) {
2598 pr_err("Invalid file: %s\n", symbol_conf.kallsyms_name);
2599 return -EINVAL;
2600 }
2601 return 0;
2602 }
2603