xref: /openbmc/linux/tools/perf/util/symbol.c (revision 0a907292)
1 // SPDX-License-Identifier: GPL-2.0
2 #include <dirent.h>
3 #include <errno.h>
4 #include <stdlib.h>
5 #include <stdio.h>
6 #include <string.h>
7 #include <linux/capability.h>
8 #include <linux/kernel.h>
9 #include <linux/mman.h>
10 #include <linux/string.h>
11 #include <linux/time64.h>
12 #include <sys/types.h>
13 #include <sys/stat.h>
14 #include <sys/param.h>
15 #include <fcntl.h>
16 #include <unistd.h>
17 #include <inttypes.h>
18 #include "annotate.h"
19 #include "build-id.h"
20 #include "cap.h"
21 #include "dso.h"
22 #include "util.h" // lsdir()
23 #include "debug.h"
24 #include "event.h"
25 #include "machine.h"
26 #include "map.h"
27 #include "symbol.h"
28 #include "map_symbol.h"
29 #include "mem-events.h"
30 #include "symsrc.h"
31 #include "strlist.h"
32 #include "intlist.h"
33 #include "namespaces.h"
34 #include "header.h"
35 #include "path.h"
36 #include <linux/ctype.h>
37 #include <linux/zalloc.h>
38 
39 #include <elf.h>
40 #include <limits.h>
41 #include <symbol/kallsyms.h>
42 #include <sys/utsname.h>
43 
44 static int dso__load_kernel_sym(struct dso *dso, struct map *map);
45 static int dso__load_guest_kernel_sym(struct dso *dso, struct map *map);
46 static bool symbol__is_idle(const char *name);
47 
48 int vmlinux_path__nr_entries;
49 char **vmlinux_path;
50 
51 struct symbol_conf symbol_conf = {
52 	.nanosecs		= false,
53 	.use_modules		= true,
54 	.try_vmlinux_path	= true,
55 	.demangle		= true,
56 	.demangle_kernel	= false,
57 	.cumulate_callchain	= true,
58 	.time_quantum		= 100 * NSEC_PER_MSEC, /* 100ms */
59 	.show_hist_headers	= true,
60 	.symfs			= "",
61 	.event_group		= true,
62 	.inline_name		= true,
63 	.res_sample		= 0,
64 };
65 
66 static enum dso_binary_type binary_type_symtab[] = {
67 	DSO_BINARY_TYPE__KALLSYMS,
68 	DSO_BINARY_TYPE__GUEST_KALLSYMS,
69 	DSO_BINARY_TYPE__JAVA_JIT,
70 	DSO_BINARY_TYPE__DEBUGLINK,
71 	DSO_BINARY_TYPE__BUILD_ID_CACHE,
72 	DSO_BINARY_TYPE__BUILD_ID_CACHE_DEBUGINFO,
73 	DSO_BINARY_TYPE__FEDORA_DEBUGINFO,
74 	DSO_BINARY_TYPE__UBUNTU_DEBUGINFO,
75 	DSO_BINARY_TYPE__BUILDID_DEBUGINFO,
76 	DSO_BINARY_TYPE__SYSTEM_PATH_DSO,
77 	DSO_BINARY_TYPE__GUEST_KMODULE,
78 	DSO_BINARY_TYPE__GUEST_KMODULE_COMP,
79 	DSO_BINARY_TYPE__SYSTEM_PATH_KMODULE,
80 	DSO_BINARY_TYPE__SYSTEM_PATH_KMODULE_COMP,
81 	DSO_BINARY_TYPE__OPENEMBEDDED_DEBUGINFO,
82 	DSO_BINARY_TYPE__MIXEDUP_UBUNTU_DEBUGINFO,
83 	DSO_BINARY_TYPE__NOT_FOUND,
84 };
85 
86 #define DSO_BINARY_TYPE__SYMTAB_CNT ARRAY_SIZE(binary_type_symtab)
87 
88 static bool symbol_type__filter(char symbol_type)
89 {
90 	symbol_type = toupper(symbol_type);
91 	return symbol_type == 'T' || symbol_type == 'W' || symbol_type == 'D' || symbol_type == 'B';
92 }
93 
94 static int prefix_underscores_count(const char *str)
95 {
96 	const char *tail = str;
97 
98 	while (*tail == '_')
99 		tail++;
100 
101 	return tail - str;
102 }
103 
104 void __weak arch__symbols__fixup_end(struct symbol *p, struct symbol *c)
105 {
106 	p->end = c->start;
107 }
108 
109 const char * __weak arch__normalize_symbol_name(const char *name)
110 {
111 	return name;
112 }
113 
114 int __weak arch__compare_symbol_names(const char *namea, const char *nameb)
115 {
116 	return strcmp(namea, nameb);
117 }
118 
119 int __weak arch__compare_symbol_names_n(const char *namea, const char *nameb,
120 					unsigned int n)
121 {
122 	return strncmp(namea, nameb, n);
123 }
124 
125 int __weak arch__choose_best_symbol(struct symbol *syma,
126 				    struct symbol *symb __maybe_unused)
127 {
128 	/* Avoid "SyS" kernel syscall aliases */
129 	if (strlen(syma->name) >= 3 && !strncmp(syma->name, "SyS", 3))
130 		return SYMBOL_B;
131 	if (strlen(syma->name) >= 10 && !strncmp(syma->name, "compat_SyS", 10))
132 		return SYMBOL_B;
133 
134 	return SYMBOL_A;
135 }
136 
137 static int choose_best_symbol(struct symbol *syma, struct symbol *symb)
138 {
139 	s64 a;
140 	s64 b;
141 	size_t na, nb;
142 
143 	/* Prefer a symbol with non zero length */
144 	a = syma->end - syma->start;
145 	b = symb->end - symb->start;
146 	if ((b == 0) && (a > 0))
147 		return SYMBOL_A;
148 	else if ((a == 0) && (b > 0))
149 		return SYMBOL_B;
150 
151 	/* Prefer a non weak symbol over a weak one */
152 	a = syma->binding == STB_WEAK;
153 	b = symb->binding == STB_WEAK;
154 	if (b && !a)
155 		return SYMBOL_A;
156 	if (a && !b)
157 		return SYMBOL_B;
158 
159 	/* Prefer a global symbol over a non global one */
160 	a = syma->binding == STB_GLOBAL;
161 	b = symb->binding == STB_GLOBAL;
162 	if (a && !b)
163 		return SYMBOL_A;
164 	if (b && !a)
165 		return SYMBOL_B;
166 
167 	/* Prefer a symbol with less underscores */
168 	a = prefix_underscores_count(syma->name);
169 	b = prefix_underscores_count(symb->name);
170 	if (b > a)
171 		return SYMBOL_A;
172 	else if (a > b)
173 		return SYMBOL_B;
174 
175 	/* Choose the symbol with the longest name */
176 	na = strlen(syma->name);
177 	nb = strlen(symb->name);
178 	if (na > nb)
179 		return SYMBOL_A;
180 	else if (na < nb)
181 		return SYMBOL_B;
182 
183 	return arch__choose_best_symbol(syma, symb);
184 }
185 
186 void symbols__fixup_duplicate(struct rb_root_cached *symbols)
187 {
188 	struct rb_node *nd;
189 	struct symbol *curr, *next;
190 
191 	if (symbol_conf.allow_aliases)
192 		return;
193 
194 	nd = rb_first_cached(symbols);
195 
196 	while (nd) {
197 		curr = rb_entry(nd, struct symbol, rb_node);
198 again:
199 		nd = rb_next(&curr->rb_node);
200 		next = rb_entry(nd, struct symbol, rb_node);
201 
202 		if (!nd)
203 			break;
204 
205 		if (curr->start != next->start)
206 			continue;
207 
208 		if (choose_best_symbol(curr, next) == SYMBOL_A) {
209 			rb_erase_cached(&next->rb_node, symbols);
210 			symbol__delete(next);
211 			goto again;
212 		} else {
213 			nd = rb_next(&curr->rb_node);
214 			rb_erase_cached(&curr->rb_node, symbols);
215 			symbol__delete(curr);
216 		}
217 	}
218 }
219 
220 void symbols__fixup_end(struct rb_root_cached *symbols)
221 {
222 	struct rb_node *nd, *prevnd = rb_first_cached(symbols);
223 	struct symbol *curr, *prev;
224 
225 	if (prevnd == NULL)
226 		return;
227 
228 	curr = rb_entry(prevnd, struct symbol, rb_node);
229 
230 	for (nd = rb_next(prevnd); nd; nd = rb_next(nd)) {
231 		prev = curr;
232 		curr = rb_entry(nd, struct symbol, rb_node);
233 
234 		if (prev->end == prev->start && prev->end != curr->start)
235 			arch__symbols__fixup_end(prev, curr);
236 	}
237 
238 	/* Last entry */
239 	if (curr->end == curr->start)
240 		curr->end = roundup(curr->start, 4096) + 4096;
241 }
242 
243 void maps__fixup_end(struct maps *maps)
244 {
245 	struct map *prev = NULL, *curr;
246 
247 	down_write(&maps->lock);
248 
249 	maps__for_each_entry(maps, curr) {
250 		if (prev != NULL && !prev->end)
251 			prev->end = curr->start;
252 
253 		prev = curr;
254 	}
255 
256 	/*
257 	 * We still haven't the actual symbols, so guess the
258 	 * last map final address.
259 	 */
260 	if (curr && !curr->end)
261 		curr->end = ~0ULL;
262 
263 	up_write(&maps->lock);
264 }
265 
266 struct symbol *symbol__new(u64 start, u64 len, u8 binding, u8 type, const char *name)
267 {
268 	size_t namelen = strlen(name) + 1;
269 	struct symbol *sym = calloc(1, (symbol_conf.priv_size +
270 					sizeof(*sym) + namelen));
271 	if (sym == NULL)
272 		return NULL;
273 
274 	if (symbol_conf.priv_size) {
275 		if (symbol_conf.init_annotation) {
276 			struct annotation *notes = (void *)sym;
277 			pthread_mutex_init(&notes->lock, NULL);
278 		}
279 		sym = ((void *)sym) + symbol_conf.priv_size;
280 	}
281 
282 	sym->start   = start;
283 	sym->end     = len ? start + len : start;
284 	sym->type    = type;
285 	sym->binding = binding;
286 	sym->namelen = namelen - 1;
287 
288 	pr_debug4("%s: %s %#" PRIx64 "-%#" PRIx64 "\n",
289 		  __func__, name, start, sym->end);
290 	memcpy(sym->name, name, namelen);
291 
292 	return sym;
293 }
294 
295 void symbol__delete(struct symbol *sym)
296 {
297 	free(((void *)sym) - symbol_conf.priv_size);
298 }
299 
300 void symbols__delete(struct rb_root_cached *symbols)
301 {
302 	struct symbol *pos;
303 	struct rb_node *next = rb_first_cached(symbols);
304 
305 	while (next) {
306 		pos = rb_entry(next, struct symbol, rb_node);
307 		next = rb_next(&pos->rb_node);
308 		rb_erase_cached(&pos->rb_node, symbols);
309 		symbol__delete(pos);
310 	}
311 }
312 
313 void __symbols__insert(struct rb_root_cached *symbols,
314 		       struct symbol *sym, bool kernel)
315 {
316 	struct rb_node **p = &symbols->rb_root.rb_node;
317 	struct rb_node *parent = NULL;
318 	const u64 ip = sym->start;
319 	struct symbol *s;
320 	bool leftmost = true;
321 
322 	if (kernel) {
323 		const char *name = sym->name;
324 		/*
325 		 * ppc64 uses function descriptors and appends a '.' to the
326 		 * start of every instruction address. Remove it.
327 		 */
328 		if (name[0] == '.')
329 			name++;
330 		sym->idle = symbol__is_idle(name);
331 	}
332 
333 	while (*p != NULL) {
334 		parent = *p;
335 		s = rb_entry(parent, struct symbol, rb_node);
336 		if (ip < s->start)
337 			p = &(*p)->rb_left;
338 		else {
339 			p = &(*p)->rb_right;
340 			leftmost = false;
341 		}
342 	}
343 	rb_link_node(&sym->rb_node, parent, p);
344 	rb_insert_color_cached(&sym->rb_node, symbols, leftmost);
345 }
346 
347 void symbols__insert(struct rb_root_cached *symbols, struct symbol *sym)
348 {
349 	__symbols__insert(symbols, sym, false);
350 }
351 
352 static struct symbol *symbols__find(struct rb_root_cached *symbols, u64 ip)
353 {
354 	struct rb_node *n;
355 
356 	if (symbols == NULL)
357 		return NULL;
358 
359 	n = symbols->rb_root.rb_node;
360 
361 	while (n) {
362 		struct symbol *s = rb_entry(n, struct symbol, rb_node);
363 
364 		if (ip < s->start)
365 			n = n->rb_left;
366 		else if (ip > s->end || (ip == s->end && ip != s->start))
367 			n = n->rb_right;
368 		else
369 			return s;
370 	}
371 
372 	return NULL;
373 }
374 
375 static struct symbol *symbols__first(struct rb_root_cached *symbols)
376 {
377 	struct rb_node *n = rb_first_cached(symbols);
378 
379 	if (n)
380 		return rb_entry(n, struct symbol, rb_node);
381 
382 	return NULL;
383 }
384 
385 static struct symbol *symbols__last(struct rb_root_cached *symbols)
386 {
387 	struct rb_node *n = rb_last(&symbols->rb_root);
388 
389 	if (n)
390 		return rb_entry(n, struct symbol, rb_node);
391 
392 	return NULL;
393 }
394 
395 static struct symbol *symbols__next(struct symbol *sym)
396 {
397 	struct rb_node *n = rb_next(&sym->rb_node);
398 
399 	if (n)
400 		return rb_entry(n, struct symbol, rb_node);
401 
402 	return NULL;
403 }
404 
405 static void symbols__insert_by_name(struct rb_root_cached *symbols, struct symbol *sym)
406 {
407 	struct rb_node **p = &symbols->rb_root.rb_node;
408 	struct rb_node *parent = NULL;
409 	struct symbol_name_rb_node *symn, *s;
410 	bool leftmost = true;
411 
412 	symn = container_of(sym, struct symbol_name_rb_node, sym);
413 
414 	while (*p != NULL) {
415 		parent = *p;
416 		s = rb_entry(parent, struct symbol_name_rb_node, rb_node);
417 		if (strcmp(sym->name, s->sym.name) < 0)
418 			p = &(*p)->rb_left;
419 		else {
420 			p = &(*p)->rb_right;
421 			leftmost = false;
422 		}
423 	}
424 	rb_link_node(&symn->rb_node, parent, p);
425 	rb_insert_color_cached(&symn->rb_node, symbols, leftmost);
426 }
427 
428 static void symbols__sort_by_name(struct rb_root_cached *symbols,
429 				  struct rb_root_cached *source)
430 {
431 	struct rb_node *nd;
432 
433 	for (nd = rb_first_cached(source); nd; nd = rb_next(nd)) {
434 		struct symbol *pos = rb_entry(nd, struct symbol, rb_node);
435 		symbols__insert_by_name(symbols, pos);
436 	}
437 }
438 
439 int symbol__match_symbol_name(const char *name, const char *str,
440 			      enum symbol_tag_include includes)
441 {
442 	const char *versioning;
443 
444 	if (includes == SYMBOL_TAG_INCLUDE__DEFAULT_ONLY &&
445 	    (versioning = strstr(name, "@@"))) {
446 		int len = strlen(str);
447 
448 		if (len < versioning - name)
449 			len = versioning - name;
450 
451 		return arch__compare_symbol_names_n(name, str, len);
452 	} else
453 		return arch__compare_symbol_names(name, str);
454 }
455 
456 static struct symbol *symbols__find_by_name(struct rb_root_cached *symbols,
457 					    const char *name,
458 					    enum symbol_tag_include includes)
459 {
460 	struct rb_node *n;
461 	struct symbol_name_rb_node *s = NULL;
462 
463 	if (symbols == NULL)
464 		return NULL;
465 
466 	n = symbols->rb_root.rb_node;
467 
468 	while (n) {
469 		int cmp;
470 
471 		s = rb_entry(n, struct symbol_name_rb_node, rb_node);
472 		cmp = symbol__match_symbol_name(s->sym.name, name, includes);
473 
474 		if (cmp > 0)
475 			n = n->rb_left;
476 		else if (cmp < 0)
477 			n = n->rb_right;
478 		else
479 			break;
480 	}
481 
482 	if (n == NULL)
483 		return NULL;
484 
485 	if (includes != SYMBOL_TAG_INCLUDE__DEFAULT_ONLY)
486 		/* return first symbol that has same name (if any) */
487 		for (n = rb_prev(n); n; n = rb_prev(n)) {
488 			struct symbol_name_rb_node *tmp;
489 
490 			tmp = rb_entry(n, struct symbol_name_rb_node, rb_node);
491 			if (arch__compare_symbol_names(tmp->sym.name, s->sym.name))
492 				break;
493 
494 			s = tmp;
495 		}
496 
497 	return &s->sym;
498 }
499 
500 void dso__reset_find_symbol_cache(struct dso *dso)
501 {
502 	dso->last_find_result.addr   = 0;
503 	dso->last_find_result.symbol = NULL;
504 }
505 
506 void dso__insert_symbol(struct dso *dso, struct symbol *sym)
507 {
508 	__symbols__insert(&dso->symbols, sym, dso->kernel);
509 
510 	/* update the symbol cache if necessary */
511 	if (dso->last_find_result.addr >= sym->start &&
512 	    (dso->last_find_result.addr < sym->end ||
513 	    sym->start == sym->end)) {
514 		dso->last_find_result.symbol = sym;
515 	}
516 }
517 
518 void dso__delete_symbol(struct dso *dso, struct symbol *sym)
519 {
520 	rb_erase_cached(&sym->rb_node, &dso->symbols);
521 	symbol__delete(sym);
522 	dso__reset_find_symbol_cache(dso);
523 }
524 
525 struct symbol *dso__find_symbol(struct dso *dso, u64 addr)
526 {
527 	if (dso->last_find_result.addr != addr || dso->last_find_result.symbol == NULL) {
528 		dso->last_find_result.addr   = addr;
529 		dso->last_find_result.symbol = symbols__find(&dso->symbols, addr);
530 	}
531 
532 	return dso->last_find_result.symbol;
533 }
534 
535 struct symbol *dso__first_symbol(struct dso *dso)
536 {
537 	return symbols__first(&dso->symbols);
538 }
539 
540 struct symbol *dso__last_symbol(struct dso *dso)
541 {
542 	return symbols__last(&dso->symbols);
543 }
544 
545 struct symbol *dso__next_symbol(struct symbol *sym)
546 {
547 	return symbols__next(sym);
548 }
549 
550 struct symbol *symbol__next_by_name(struct symbol *sym)
551 {
552 	struct symbol_name_rb_node *s = container_of(sym, struct symbol_name_rb_node, sym);
553 	struct rb_node *n = rb_next(&s->rb_node);
554 
555 	return n ? &rb_entry(n, struct symbol_name_rb_node, rb_node)->sym : NULL;
556 }
557 
558  /*
559   * Returns first symbol that matched with @name.
560   */
561 struct symbol *dso__find_symbol_by_name(struct dso *dso, const char *name)
562 {
563 	struct symbol *s = symbols__find_by_name(&dso->symbol_names, name,
564 						 SYMBOL_TAG_INCLUDE__NONE);
565 	if (!s)
566 		s = symbols__find_by_name(&dso->symbol_names, name,
567 					  SYMBOL_TAG_INCLUDE__DEFAULT_ONLY);
568 	return s;
569 }
570 
571 void dso__sort_by_name(struct dso *dso)
572 {
573 	dso__set_sorted_by_name(dso);
574 	return symbols__sort_by_name(&dso->symbol_names, &dso->symbols);
575 }
576 
577 /*
578  * While we find nice hex chars, build a long_val.
579  * Return number of chars processed.
580  */
581 static int hex2u64(const char *ptr, u64 *long_val)
582 {
583 	char *p;
584 
585 	*long_val = strtoull(ptr, &p, 16);
586 
587 	return p - ptr;
588 }
589 
590 
591 int modules__parse(const char *filename, void *arg,
592 		   int (*process_module)(void *arg, const char *name,
593 					 u64 start, u64 size))
594 {
595 	char *line = NULL;
596 	size_t n;
597 	FILE *file;
598 	int err = 0;
599 
600 	file = fopen(filename, "r");
601 	if (file == NULL)
602 		return -1;
603 
604 	while (1) {
605 		char name[PATH_MAX];
606 		u64 start, size;
607 		char *sep, *endptr;
608 		ssize_t line_len;
609 
610 		line_len = getline(&line, &n, file);
611 		if (line_len < 0) {
612 			if (feof(file))
613 				break;
614 			err = -1;
615 			goto out;
616 		}
617 
618 		if (!line) {
619 			err = -1;
620 			goto out;
621 		}
622 
623 		line[--line_len] = '\0'; /* \n */
624 
625 		sep = strrchr(line, 'x');
626 		if (sep == NULL)
627 			continue;
628 
629 		hex2u64(sep + 1, &start);
630 
631 		sep = strchr(line, ' ');
632 		if (sep == NULL)
633 			continue;
634 
635 		*sep = '\0';
636 
637 		scnprintf(name, sizeof(name), "[%s]", line);
638 
639 		size = strtoul(sep + 1, &endptr, 0);
640 		if (*endptr != ' ' && *endptr != '\t')
641 			continue;
642 
643 		err = process_module(arg, name, start, size);
644 		if (err)
645 			break;
646 	}
647 out:
648 	free(line);
649 	fclose(file);
650 	return err;
651 }
652 
653 /*
654  * These are symbols in the kernel image, so make sure that
655  * sym is from a kernel DSO.
656  */
657 static bool symbol__is_idle(const char *name)
658 {
659 	const char * const idle_symbols[] = {
660 		"acpi_idle_do_entry",
661 		"acpi_processor_ffh_cstate_enter",
662 		"arch_cpu_idle",
663 		"cpu_idle",
664 		"cpu_startup_entry",
665 		"idle_cpu",
666 		"intel_idle",
667 		"default_idle",
668 		"native_safe_halt",
669 		"enter_idle",
670 		"exit_idle",
671 		"mwait_idle",
672 		"mwait_idle_with_hints",
673 		"mwait_idle_with_hints.constprop.0",
674 		"poll_idle",
675 		"ppc64_runlatch_off",
676 		"pseries_dedicated_idle_sleep",
677 		"psw_idle",
678 		"psw_idle_exit",
679 		NULL
680 	};
681 	int i;
682 	static struct strlist *idle_symbols_list;
683 
684 	if (idle_symbols_list)
685 		return strlist__has_entry(idle_symbols_list, name);
686 
687 	idle_symbols_list = strlist__new(NULL, NULL);
688 
689 	for (i = 0; idle_symbols[i]; i++)
690 		strlist__add(idle_symbols_list, idle_symbols[i]);
691 
692 	return strlist__has_entry(idle_symbols_list, name);
693 }
694 
695 static int map__process_kallsym_symbol(void *arg, const char *name,
696 				       char type, u64 start)
697 {
698 	struct symbol *sym;
699 	struct dso *dso = arg;
700 	struct rb_root_cached *root = &dso->symbols;
701 
702 	if (!symbol_type__filter(type))
703 		return 0;
704 
705 	/* Ignore local symbols for ARM modules */
706 	if (name[0] == '$')
707 		return 0;
708 
709 	/*
710 	 * module symbols are not sorted so we add all
711 	 * symbols, setting length to 0, and rely on
712 	 * symbols__fixup_end() to fix it up.
713 	 */
714 	sym = symbol__new(start, 0, kallsyms2elf_binding(type), kallsyms2elf_type(type), name);
715 	if (sym == NULL)
716 		return -ENOMEM;
717 	/*
718 	 * We will pass the symbols to the filter later, in
719 	 * map__split_kallsyms, when we have split the maps per module
720 	 */
721 	__symbols__insert(root, sym, !strchr(name, '['));
722 
723 	return 0;
724 }
725 
726 /*
727  * Loads the function entries in /proc/kallsyms into kernel_map->dso,
728  * so that we can in the next step set the symbol ->end address and then
729  * call kernel_maps__split_kallsyms.
730  */
731 static int dso__load_all_kallsyms(struct dso *dso, const char *filename)
732 {
733 	return kallsyms__parse(filename, dso, map__process_kallsym_symbol);
734 }
735 
736 static int maps__split_kallsyms_for_kcore(struct maps *kmaps, struct dso *dso)
737 {
738 	struct map *curr_map;
739 	struct symbol *pos;
740 	int count = 0;
741 	struct rb_root_cached old_root = dso->symbols;
742 	struct rb_root_cached *root = &dso->symbols;
743 	struct rb_node *next = rb_first_cached(root);
744 
745 	if (!kmaps)
746 		return -1;
747 
748 	*root = RB_ROOT_CACHED;
749 
750 	while (next) {
751 		char *module;
752 
753 		pos = rb_entry(next, struct symbol, rb_node);
754 		next = rb_next(&pos->rb_node);
755 
756 		rb_erase_cached(&pos->rb_node, &old_root);
757 		RB_CLEAR_NODE(&pos->rb_node);
758 		module = strchr(pos->name, '\t');
759 		if (module)
760 			*module = '\0';
761 
762 		curr_map = maps__find(kmaps, pos->start);
763 
764 		if (!curr_map) {
765 			symbol__delete(pos);
766 			continue;
767 		}
768 
769 		pos->start -= curr_map->start - curr_map->pgoff;
770 		if (pos->end > curr_map->end)
771 			pos->end = curr_map->end;
772 		if (pos->end)
773 			pos->end -= curr_map->start - curr_map->pgoff;
774 		symbols__insert(&curr_map->dso->symbols, pos);
775 		++count;
776 	}
777 
778 	/* Symbols have been adjusted */
779 	dso->adjust_symbols = 1;
780 
781 	return count;
782 }
783 
784 /*
785  * Split the symbols into maps, making sure there are no overlaps, i.e. the
786  * kernel range is broken in several maps, named [kernel].N, as we don't have
787  * the original ELF section names vmlinux have.
788  */
789 static int maps__split_kallsyms(struct maps *kmaps, struct dso *dso, u64 delta,
790 				struct map *initial_map)
791 {
792 	struct machine *machine;
793 	struct map *curr_map = initial_map;
794 	struct symbol *pos;
795 	int count = 0, moved = 0;
796 	struct rb_root_cached *root = &dso->symbols;
797 	struct rb_node *next = rb_first_cached(root);
798 	int kernel_range = 0;
799 	bool x86_64;
800 
801 	if (!kmaps)
802 		return -1;
803 
804 	machine = kmaps->machine;
805 
806 	x86_64 = machine__is(machine, "x86_64");
807 
808 	while (next) {
809 		char *module;
810 
811 		pos = rb_entry(next, struct symbol, rb_node);
812 		next = rb_next(&pos->rb_node);
813 
814 		module = strchr(pos->name, '\t');
815 		if (module) {
816 			if (!symbol_conf.use_modules)
817 				goto discard_symbol;
818 
819 			*module++ = '\0';
820 
821 			if (strcmp(curr_map->dso->short_name, module)) {
822 				if (curr_map != initial_map &&
823 				    dso->kernel == DSO_SPACE__KERNEL_GUEST &&
824 				    machine__is_default_guest(machine)) {
825 					/*
826 					 * We assume all symbols of a module are
827 					 * continuous in * kallsyms, so curr_map
828 					 * points to a module and all its
829 					 * symbols are in its kmap. Mark it as
830 					 * loaded.
831 					 */
832 					dso__set_loaded(curr_map->dso);
833 				}
834 
835 				curr_map = maps__find_by_name(kmaps, module);
836 				if (curr_map == NULL) {
837 					pr_debug("%s/proc/{kallsyms,modules} "
838 					         "inconsistency while looking "
839 						 "for \"%s\" module!\n",
840 						 machine->root_dir, module);
841 					curr_map = initial_map;
842 					goto discard_symbol;
843 				}
844 
845 				if (curr_map->dso->loaded &&
846 				    !machine__is_default_guest(machine))
847 					goto discard_symbol;
848 			}
849 			/*
850 			 * So that we look just like we get from .ko files,
851 			 * i.e. not prelinked, relative to initial_map->start.
852 			 */
853 			pos->start = curr_map->map_ip(curr_map, pos->start);
854 			pos->end   = curr_map->map_ip(curr_map, pos->end);
855 		} else if (x86_64 && is_entry_trampoline(pos->name)) {
856 			/*
857 			 * These symbols are not needed anymore since the
858 			 * trampoline maps refer to the text section and it's
859 			 * symbols instead. Avoid having to deal with
860 			 * relocations, and the assumption that the first symbol
861 			 * is the start of kernel text, by simply removing the
862 			 * symbols at this point.
863 			 */
864 			goto discard_symbol;
865 		} else if (curr_map != initial_map) {
866 			char dso_name[PATH_MAX];
867 			struct dso *ndso;
868 
869 			if (delta) {
870 				/* Kernel was relocated at boot time */
871 				pos->start -= delta;
872 				pos->end -= delta;
873 			}
874 
875 			if (count == 0) {
876 				curr_map = initial_map;
877 				goto add_symbol;
878 			}
879 
880 			if (dso->kernel == DSO_SPACE__KERNEL_GUEST)
881 				snprintf(dso_name, sizeof(dso_name),
882 					"[guest.kernel].%d",
883 					kernel_range++);
884 			else
885 				snprintf(dso_name, sizeof(dso_name),
886 					"[kernel].%d",
887 					kernel_range++);
888 
889 			ndso = dso__new(dso_name);
890 			if (ndso == NULL)
891 				return -1;
892 
893 			ndso->kernel = dso->kernel;
894 
895 			curr_map = map__new2(pos->start, ndso);
896 			if (curr_map == NULL) {
897 				dso__put(ndso);
898 				return -1;
899 			}
900 
901 			curr_map->map_ip = curr_map->unmap_ip = identity__map_ip;
902 			maps__insert(kmaps, curr_map);
903 			++kernel_range;
904 		} else if (delta) {
905 			/* Kernel was relocated at boot time */
906 			pos->start -= delta;
907 			pos->end -= delta;
908 		}
909 add_symbol:
910 		if (curr_map != initial_map) {
911 			rb_erase_cached(&pos->rb_node, root);
912 			symbols__insert(&curr_map->dso->symbols, pos);
913 			++moved;
914 		} else
915 			++count;
916 
917 		continue;
918 discard_symbol:
919 		rb_erase_cached(&pos->rb_node, root);
920 		symbol__delete(pos);
921 	}
922 
923 	if (curr_map != initial_map &&
924 	    dso->kernel == DSO_SPACE__KERNEL_GUEST &&
925 	    machine__is_default_guest(kmaps->machine)) {
926 		dso__set_loaded(curr_map->dso);
927 	}
928 
929 	return count + moved;
930 }
931 
932 bool symbol__restricted_filename(const char *filename,
933 				 const char *restricted_filename)
934 {
935 	bool restricted = false;
936 
937 	if (symbol_conf.kptr_restrict) {
938 		char *r = realpath(filename, NULL);
939 
940 		if (r != NULL) {
941 			restricted = strcmp(r, restricted_filename) == 0;
942 			free(r);
943 			return restricted;
944 		}
945 	}
946 
947 	return restricted;
948 }
949 
950 struct module_info {
951 	struct rb_node rb_node;
952 	char *name;
953 	u64 start;
954 };
955 
956 static void add_module(struct module_info *mi, struct rb_root *modules)
957 {
958 	struct rb_node **p = &modules->rb_node;
959 	struct rb_node *parent = NULL;
960 	struct module_info *m;
961 
962 	while (*p != NULL) {
963 		parent = *p;
964 		m = rb_entry(parent, struct module_info, rb_node);
965 		if (strcmp(mi->name, m->name) < 0)
966 			p = &(*p)->rb_left;
967 		else
968 			p = &(*p)->rb_right;
969 	}
970 	rb_link_node(&mi->rb_node, parent, p);
971 	rb_insert_color(&mi->rb_node, modules);
972 }
973 
974 static void delete_modules(struct rb_root *modules)
975 {
976 	struct module_info *mi;
977 	struct rb_node *next = rb_first(modules);
978 
979 	while (next) {
980 		mi = rb_entry(next, struct module_info, rb_node);
981 		next = rb_next(&mi->rb_node);
982 		rb_erase(&mi->rb_node, modules);
983 		zfree(&mi->name);
984 		free(mi);
985 	}
986 }
987 
988 static struct module_info *find_module(const char *name,
989 				       struct rb_root *modules)
990 {
991 	struct rb_node *n = modules->rb_node;
992 
993 	while (n) {
994 		struct module_info *m;
995 		int cmp;
996 
997 		m = rb_entry(n, struct module_info, rb_node);
998 		cmp = strcmp(name, m->name);
999 		if (cmp < 0)
1000 			n = n->rb_left;
1001 		else if (cmp > 0)
1002 			n = n->rb_right;
1003 		else
1004 			return m;
1005 	}
1006 
1007 	return NULL;
1008 }
1009 
1010 static int __read_proc_modules(void *arg, const char *name, u64 start,
1011 			       u64 size __maybe_unused)
1012 {
1013 	struct rb_root *modules = arg;
1014 	struct module_info *mi;
1015 
1016 	mi = zalloc(sizeof(struct module_info));
1017 	if (!mi)
1018 		return -ENOMEM;
1019 
1020 	mi->name = strdup(name);
1021 	mi->start = start;
1022 
1023 	if (!mi->name) {
1024 		free(mi);
1025 		return -ENOMEM;
1026 	}
1027 
1028 	add_module(mi, modules);
1029 
1030 	return 0;
1031 }
1032 
1033 static int read_proc_modules(const char *filename, struct rb_root *modules)
1034 {
1035 	if (symbol__restricted_filename(filename, "/proc/modules"))
1036 		return -1;
1037 
1038 	if (modules__parse(filename, modules, __read_proc_modules)) {
1039 		delete_modules(modules);
1040 		return -1;
1041 	}
1042 
1043 	return 0;
1044 }
1045 
1046 int compare_proc_modules(const char *from, const char *to)
1047 {
1048 	struct rb_root from_modules = RB_ROOT;
1049 	struct rb_root to_modules = RB_ROOT;
1050 	struct rb_node *from_node, *to_node;
1051 	struct module_info *from_m, *to_m;
1052 	int ret = -1;
1053 
1054 	if (read_proc_modules(from, &from_modules))
1055 		return -1;
1056 
1057 	if (read_proc_modules(to, &to_modules))
1058 		goto out_delete_from;
1059 
1060 	from_node = rb_first(&from_modules);
1061 	to_node = rb_first(&to_modules);
1062 	while (from_node) {
1063 		if (!to_node)
1064 			break;
1065 
1066 		from_m = rb_entry(from_node, struct module_info, rb_node);
1067 		to_m = rb_entry(to_node, struct module_info, rb_node);
1068 
1069 		if (from_m->start != to_m->start ||
1070 		    strcmp(from_m->name, to_m->name))
1071 			break;
1072 
1073 		from_node = rb_next(from_node);
1074 		to_node = rb_next(to_node);
1075 	}
1076 
1077 	if (!from_node && !to_node)
1078 		ret = 0;
1079 
1080 	delete_modules(&to_modules);
1081 out_delete_from:
1082 	delete_modules(&from_modules);
1083 
1084 	return ret;
1085 }
1086 
1087 static int do_validate_kcore_modules(const char *filename, struct maps *kmaps)
1088 {
1089 	struct rb_root modules = RB_ROOT;
1090 	struct map *old_map;
1091 	int err;
1092 
1093 	err = read_proc_modules(filename, &modules);
1094 	if (err)
1095 		return err;
1096 
1097 	maps__for_each_entry(kmaps, old_map) {
1098 		struct module_info *mi;
1099 
1100 		if (!__map__is_kmodule(old_map)) {
1101 			continue;
1102 		}
1103 
1104 		/* Module must be in memory at the same address */
1105 		mi = find_module(old_map->dso->short_name, &modules);
1106 		if (!mi || mi->start != old_map->start) {
1107 			err = -EINVAL;
1108 			goto out;
1109 		}
1110 	}
1111 out:
1112 	delete_modules(&modules);
1113 	return err;
1114 }
1115 
1116 /*
1117  * If kallsyms is referenced by name then we look for filename in the same
1118  * directory.
1119  */
1120 static bool filename_from_kallsyms_filename(char *filename,
1121 					    const char *base_name,
1122 					    const char *kallsyms_filename)
1123 {
1124 	char *name;
1125 
1126 	strcpy(filename, kallsyms_filename);
1127 	name = strrchr(filename, '/');
1128 	if (!name)
1129 		return false;
1130 
1131 	name += 1;
1132 
1133 	if (!strcmp(name, "kallsyms")) {
1134 		strcpy(name, base_name);
1135 		return true;
1136 	}
1137 
1138 	return false;
1139 }
1140 
1141 static int validate_kcore_modules(const char *kallsyms_filename,
1142 				  struct map *map)
1143 {
1144 	struct maps *kmaps = map__kmaps(map);
1145 	char modules_filename[PATH_MAX];
1146 
1147 	if (!kmaps)
1148 		return -EINVAL;
1149 
1150 	if (!filename_from_kallsyms_filename(modules_filename, "modules",
1151 					     kallsyms_filename))
1152 		return -EINVAL;
1153 
1154 	if (do_validate_kcore_modules(modules_filename, kmaps))
1155 		return -EINVAL;
1156 
1157 	return 0;
1158 }
1159 
1160 static int validate_kcore_addresses(const char *kallsyms_filename,
1161 				    struct map *map)
1162 {
1163 	struct kmap *kmap = map__kmap(map);
1164 
1165 	if (!kmap)
1166 		return -EINVAL;
1167 
1168 	if (kmap->ref_reloc_sym && kmap->ref_reloc_sym->name) {
1169 		u64 start;
1170 
1171 		if (kallsyms__get_function_start(kallsyms_filename,
1172 						 kmap->ref_reloc_sym->name, &start))
1173 			return -ENOENT;
1174 		if (start != kmap->ref_reloc_sym->addr)
1175 			return -EINVAL;
1176 	}
1177 
1178 	return validate_kcore_modules(kallsyms_filename, map);
1179 }
1180 
1181 struct kcore_mapfn_data {
1182 	struct dso *dso;
1183 	struct list_head maps;
1184 };
1185 
1186 static int kcore_mapfn(u64 start, u64 len, u64 pgoff, void *data)
1187 {
1188 	struct kcore_mapfn_data *md = data;
1189 	struct map *map;
1190 
1191 	map = map__new2(start, md->dso);
1192 	if (map == NULL)
1193 		return -ENOMEM;
1194 
1195 	map->end = map->start + len;
1196 	map->pgoff = pgoff;
1197 
1198 	list_add(&map->node, &md->maps);
1199 
1200 	return 0;
1201 }
1202 
1203 /*
1204  * Merges map into maps by splitting the new map within the existing map
1205  * regions.
1206  */
1207 int maps__merge_in(struct maps *kmaps, struct map *new_map)
1208 {
1209 	struct map *old_map;
1210 	LIST_HEAD(merged);
1211 
1212 	maps__for_each_entry(kmaps, old_map) {
1213 		/* no overload with this one */
1214 		if (new_map->end < old_map->start ||
1215 		    new_map->start >= old_map->end)
1216 			continue;
1217 
1218 		if (new_map->start < old_map->start) {
1219 			/*
1220 			 * |new......
1221 			 *       |old....
1222 			 */
1223 			if (new_map->end < old_map->end) {
1224 				/*
1225 				 * |new......|     -> |new..|
1226 				 *       |old....| ->       |old....|
1227 				 */
1228 				new_map->end = old_map->start;
1229 			} else {
1230 				/*
1231 				 * |new.............| -> |new..|       |new..|
1232 				 *       |old....|    ->       |old....|
1233 				 */
1234 				struct map *m = map__clone(new_map);
1235 
1236 				if (!m)
1237 					return -ENOMEM;
1238 
1239 				m->end = old_map->start;
1240 				list_add_tail(&m->node, &merged);
1241 				new_map->pgoff += old_map->end - new_map->start;
1242 				new_map->start = old_map->end;
1243 			}
1244 		} else {
1245 			/*
1246 			 *      |new......
1247 			 * |old....
1248 			 */
1249 			if (new_map->end < old_map->end) {
1250 				/*
1251 				 *      |new..|   -> x
1252 				 * |old.........| -> |old.........|
1253 				 */
1254 				map__put(new_map);
1255 				new_map = NULL;
1256 				break;
1257 			} else {
1258 				/*
1259 				 *      |new......| ->         |new...|
1260 				 * |old....|        -> |old....|
1261 				 */
1262 				new_map->pgoff += old_map->end - new_map->start;
1263 				new_map->start = old_map->end;
1264 			}
1265 		}
1266 	}
1267 
1268 	while (!list_empty(&merged)) {
1269 		old_map = list_entry(merged.next, struct map, node);
1270 		list_del_init(&old_map->node);
1271 		maps__insert(kmaps, old_map);
1272 		map__put(old_map);
1273 	}
1274 
1275 	if (new_map) {
1276 		maps__insert(kmaps, new_map);
1277 		map__put(new_map);
1278 	}
1279 	return 0;
1280 }
1281 
1282 static int dso__load_kcore(struct dso *dso, struct map *map,
1283 			   const char *kallsyms_filename)
1284 {
1285 	struct maps *kmaps = map__kmaps(map);
1286 	struct kcore_mapfn_data md;
1287 	struct map *old_map, *new_map, *replacement_map = NULL, *next;
1288 	struct machine *machine;
1289 	bool is_64_bit;
1290 	int err, fd;
1291 	char kcore_filename[PATH_MAX];
1292 	u64 stext;
1293 
1294 	if (!kmaps)
1295 		return -EINVAL;
1296 
1297 	machine = kmaps->machine;
1298 
1299 	/* This function requires that the map is the kernel map */
1300 	if (!__map__is_kernel(map))
1301 		return -EINVAL;
1302 
1303 	if (!filename_from_kallsyms_filename(kcore_filename, "kcore",
1304 					     kallsyms_filename))
1305 		return -EINVAL;
1306 
1307 	/* Modules and kernel must be present at their original addresses */
1308 	if (validate_kcore_addresses(kallsyms_filename, map))
1309 		return -EINVAL;
1310 
1311 	md.dso = dso;
1312 	INIT_LIST_HEAD(&md.maps);
1313 
1314 	fd = open(kcore_filename, O_RDONLY);
1315 	if (fd < 0) {
1316 		pr_debug("Failed to open %s. Note /proc/kcore requires CAP_SYS_RAWIO capability to access.\n",
1317 			 kcore_filename);
1318 		return -EINVAL;
1319 	}
1320 
1321 	/* Read new maps into temporary lists */
1322 	err = file__read_maps(fd, map->prot & PROT_EXEC, kcore_mapfn, &md,
1323 			      &is_64_bit);
1324 	if (err)
1325 		goto out_err;
1326 	dso->is_64_bit = is_64_bit;
1327 
1328 	if (list_empty(&md.maps)) {
1329 		err = -EINVAL;
1330 		goto out_err;
1331 	}
1332 
1333 	/* Remove old maps */
1334 	maps__for_each_entry_safe(kmaps, old_map, next) {
1335 		/*
1336 		 * We need to preserve eBPF maps even if they are
1337 		 * covered by kcore, because we need to access
1338 		 * eBPF dso for source data.
1339 		 */
1340 		if (old_map != map && !__map__is_bpf_prog(old_map))
1341 			maps__remove(kmaps, old_map);
1342 	}
1343 	machine->trampolines_mapped = false;
1344 
1345 	/* Find the kernel map using the '_stext' symbol */
1346 	if (!kallsyms__get_function_start(kallsyms_filename, "_stext", &stext)) {
1347 		list_for_each_entry(new_map, &md.maps, node) {
1348 			if (stext >= new_map->start && stext < new_map->end) {
1349 				replacement_map = new_map;
1350 				break;
1351 			}
1352 		}
1353 	}
1354 
1355 	if (!replacement_map)
1356 		replacement_map = list_entry(md.maps.next, struct map, node);
1357 
1358 	/* Add new maps */
1359 	while (!list_empty(&md.maps)) {
1360 		new_map = list_entry(md.maps.next, struct map, node);
1361 		list_del_init(&new_map->node);
1362 		if (new_map == replacement_map) {
1363 			map->start	= new_map->start;
1364 			map->end	= new_map->end;
1365 			map->pgoff	= new_map->pgoff;
1366 			map->map_ip	= new_map->map_ip;
1367 			map->unmap_ip	= new_map->unmap_ip;
1368 			/* Ensure maps are correctly ordered */
1369 			map__get(map);
1370 			maps__remove(kmaps, map);
1371 			maps__insert(kmaps, map);
1372 			map__put(map);
1373 			map__put(new_map);
1374 		} else {
1375 			/*
1376 			 * Merge kcore map into existing maps,
1377 			 * and ensure that current maps (eBPF)
1378 			 * stay intact.
1379 			 */
1380 			if (maps__merge_in(kmaps, new_map))
1381 				goto out_err;
1382 		}
1383 	}
1384 
1385 	if (machine__is(machine, "x86_64")) {
1386 		u64 addr;
1387 
1388 		/*
1389 		 * If one of the corresponding symbols is there, assume the
1390 		 * entry trampoline maps are too.
1391 		 */
1392 		if (!kallsyms__get_function_start(kallsyms_filename,
1393 						  ENTRY_TRAMPOLINE_NAME,
1394 						  &addr))
1395 			machine->trampolines_mapped = true;
1396 	}
1397 
1398 	/*
1399 	 * Set the data type and long name so that kcore can be read via
1400 	 * dso__data_read_addr().
1401 	 */
1402 	if (dso->kernel == DSO_SPACE__KERNEL_GUEST)
1403 		dso->binary_type = DSO_BINARY_TYPE__GUEST_KCORE;
1404 	else
1405 		dso->binary_type = DSO_BINARY_TYPE__KCORE;
1406 	dso__set_long_name(dso, strdup(kcore_filename), true);
1407 
1408 	close(fd);
1409 
1410 	if (map->prot & PROT_EXEC)
1411 		pr_debug("Using %s for kernel object code\n", kcore_filename);
1412 	else
1413 		pr_debug("Using %s for kernel data\n", kcore_filename);
1414 
1415 	return 0;
1416 
1417 out_err:
1418 	while (!list_empty(&md.maps)) {
1419 		map = list_entry(md.maps.next, struct map, node);
1420 		list_del_init(&map->node);
1421 		map__put(map);
1422 	}
1423 	close(fd);
1424 	return -EINVAL;
1425 }
1426 
1427 /*
1428  * If the kernel is relocated at boot time, kallsyms won't match.  Compute the
1429  * delta based on the relocation reference symbol.
1430  */
1431 static int kallsyms__delta(struct kmap *kmap, const char *filename, u64 *delta)
1432 {
1433 	u64 addr;
1434 
1435 	if (!kmap->ref_reloc_sym || !kmap->ref_reloc_sym->name)
1436 		return 0;
1437 
1438 	if (kallsyms__get_function_start(filename, kmap->ref_reloc_sym->name, &addr))
1439 		return -1;
1440 
1441 	*delta = addr - kmap->ref_reloc_sym->addr;
1442 	return 0;
1443 }
1444 
1445 int __dso__load_kallsyms(struct dso *dso, const char *filename,
1446 			 struct map *map, bool no_kcore)
1447 {
1448 	struct kmap *kmap = map__kmap(map);
1449 	u64 delta = 0;
1450 
1451 	if (symbol__restricted_filename(filename, "/proc/kallsyms"))
1452 		return -1;
1453 
1454 	if (!kmap || !kmap->kmaps)
1455 		return -1;
1456 
1457 	if (dso__load_all_kallsyms(dso, filename) < 0)
1458 		return -1;
1459 
1460 	if (kallsyms__delta(kmap, filename, &delta))
1461 		return -1;
1462 
1463 	symbols__fixup_end(&dso->symbols);
1464 	symbols__fixup_duplicate(&dso->symbols);
1465 
1466 	if (dso->kernel == DSO_SPACE__KERNEL_GUEST)
1467 		dso->symtab_type = DSO_BINARY_TYPE__GUEST_KALLSYMS;
1468 	else
1469 		dso->symtab_type = DSO_BINARY_TYPE__KALLSYMS;
1470 
1471 	if (!no_kcore && !dso__load_kcore(dso, map, filename))
1472 		return maps__split_kallsyms_for_kcore(kmap->kmaps, dso);
1473 	else
1474 		return maps__split_kallsyms(kmap->kmaps, dso, delta, map);
1475 }
1476 
1477 int dso__load_kallsyms(struct dso *dso, const char *filename,
1478 		       struct map *map)
1479 {
1480 	return __dso__load_kallsyms(dso, filename, map, false);
1481 }
1482 
1483 static int dso__load_perf_map(const char *map_path, struct dso *dso)
1484 {
1485 	char *line = NULL;
1486 	size_t n;
1487 	FILE *file;
1488 	int nr_syms = 0;
1489 
1490 	file = fopen(map_path, "r");
1491 	if (file == NULL)
1492 		goto out_failure;
1493 
1494 	while (!feof(file)) {
1495 		u64 start, size;
1496 		struct symbol *sym;
1497 		int line_len, len;
1498 
1499 		line_len = getline(&line, &n, file);
1500 		if (line_len < 0)
1501 			break;
1502 
1503 		if (!line)
1504 			goto out_failure;
1505 
1506 		line[--line_len] = '\0'; /* \n */
1507 
1508 		len = hex2u64(line, &start);
1509 
1510 		len++;
1511 		if (len + 2 >= line_len)
1512 			continue;
1513 
1514 		len += hex2u64(line + len, &size);
1515 
1516 		len++;
1517 		if (len + 2 >= line_len)
1518 			continue;
1519 
1520 		sym = symbol__new(start, size, STB_GLOBAL, STT_FUNC, line + len);
1521 
1522 		if (sym == NULL)
1523 			goto out_delete_line;
1524 
1525 		symbols__insert(&dso->symbols, sym);
1526 		nr_syms++;
1527 	}
1528 
1529 	free(line);
1530 	fclose(file);
1531 
1532 	return nr_syms;
1533 
1534 out_delete_line:
1535 	free(line);
1536 out_failure:
1537 	return -1;
1538 }
1539 
1540 #ifdef HAVE_LIBBFD_SUPPORT
1541 #define PACKAGE 'perf'
1542 #include <bfd.h>
1543 
1544 static int bfd_symbols__cmpvalue(const void *a, const void *b)
1545 {
1546 	const asymbol *as = *(const asymbol **)a, *bs = *(const asymbol **)b;
1547 
1548 	if (bfd_asymbol_value(as) != bfd_asymbol_value(bs))
1549 		return bfd_asymbol_value(as) - bfd_asymbol_value(bs);
1550 
1551 	return bfd_asymbol_name(as)[0] - bfd_asymbol_name(bs)[0];
1552 }
1553 
1554 static int bfd2elf_binding(asymbol *symbol)
1555 {
1556 	if (symbol->flags & BSF_WEAK)
1557 		return STB_WEAK;
1558 	if (symbol->flags & BSF_GLOBAL)
1559 		return STB_GLOBAL;
1560 	if (symbol->flags & BSF_LOCAL)
1561 		return STB_LOCAL;
1562 	return -1;
1563 }
1564 
1565 int dso__load_bfd_symbols(struct dso *dso, const char *debugfile)
1566 {
1567 	int err = -1;
1568 	long symbols_size, symbols_count, i;
1569 	asection *section;
1570 	asymbol **symbols, *sym;
1571 	struct symbol *symbol;
1572 	bfd *abfd;
1573 	u64 start, len;
1574 
1575 	abfd = bfd_openr(debugfile, NULL);
1576 	if (!abfd)
1577 		return -1;
1578 
1579 	if (!bfd_check_format(abfd, bfd_object)) {
1580 		pr_debug2("%s: cannot read %s bfd file.\n", __func__,
1581 			  dso->long_name);
1582 		goto out_close;
1583 	}
1584 
1585 	if (bfd_get_flavour(abfd) == bfd_target_elf_flavour)
1586 		goto out_close;
1587 
1588 	symbols_size = bfd_get_symtab_upper_bound(abfd);
1589 	if (symbols_size == 0) {
1590 		bfd_close(abfd);
1591 		return 0;
1592 	}
1593 
1594 	if (symbols_size < 0)
1595 		goto out_close;
1596 
1597 	symbols = malloc(symbols_size);
1598 	if (!symbols)
1599 		goto out_close;
1600 
1601 	symbols_count = bfd_canonicalize_symtab(abfd, symbols);
1602 	if (symbols_count < 0)
1603 		goto out_free;
1604 
1605 	section = bfd_get_section_by_name(abfd, ".text");
1606 	if (section) {
1607 		for (i = 0; i < symbols_count; ++i) {
1608 			if (!strcmp(bfd_asymbol_name(symbols[i]), "__ImageBase") ||
1609 			    !strcmp(bfd_asymbol_name(symbols[i]), "__image_base__"))
1610 				break;
1611 		}
1612 		if (i < symbols_count) {
1613 			/* PE symbols can only have 4 bytes, so use .text high bits */
1614 			dso->text_offset = section->vma - (u32)section->vma;
1615 			dso->text_offset += (u32)bfd_asymbol_value(symbols[i]);
1616 		} else {
1617 			dso->text_offset = section->vma - section->filepos;
1618 		}
1619 	}
1620 
1621 	qsort(symbols, symbols_count, sizeof(asymbol *), bfd_symbols__cmpvalue);
1622 
1623 #ifdef bfd_get_section
1624 #define bfd_asymbol_section bfd_get_section
1625 #endif
1626 	for (i = 0; i < symbols_count; ++i) {
1627 		sym = symbols[i];
1628 		section = bfd_asymbol_section(sym);
1629 		if (bfd2elf_binding(sym) < 0)
1630 			continue;
1631 
1632 		while (i + 1 < symbols_count &&
1633 		       bfd_asymbol_section(symbols[i + 1]) == section &&
1634 		       bfd2elf_binding(symbols[i + 1]) < 0)
1635 			i++;
1636 
1637 		if (i + 1 < symbols_count &&
1638 		    bfd_asymbol_section(symbols[i + 1]) == section)
1639 			len = symbols[i + 1]->value - sym->value;
1640 		else
1641 			len = section->size - sym->value;
1642 
1643 		start = bfd_asymbol_value(sym) - dso->text_offset;
1644 		symbol = symbol__new(start, len, bfd2elf_binding(sym), STT_FUNC,
1645 				     bfd_asymbol_name(sym));
1646 		if (!symbol)
1647 			goto out_free;
1648 
1649 		symbols__insert(&dso->symbols, symbol);
1650 	}
1651 #ifdef bfd_get_section
1652 #undef bfd_asymbol_section
1653 #endif
1654 
1655 	symbols__fixup_end(&dso->symbols);
1656 	symbols__fixup_duplicate(&dso->symbols);
1657 	dso->adjust_symbols = 1;
1658 
1659 	err = 0;
1660 out_free:
1661 	free(symbols);
1662 out_close:
1663 	bfd_close(abfd);
1664 	return err;
1665 }
1666 #endif
1667 
1668 static bool dso__is_compatible_symtab_type(struct dso *dso, bool kmod,
1669 					   enum dso_binary_type type)
1670 {
1671 	switch (type) {
1672 	case DSO_BINARY_TYPE__JAVA_JIT:
1673 	case DSO_BINARY_TYPE__DEBUGLINK:
1674 	case DSO_BINARY_TYPE__SYSTEM_PATH_DSO:
1675 	case DSO_BINARY_TYPE__FEDORA_DEBUGINFO:
1676 	case DSO_BINARY_TYPE__UBUNTU_DEBUGINFO:
1677 	case DSO_BINARY_TYPE__MIXEDUP_UBUNTU_DEBUGINFO:
1678 	case DSO_BINARY_TYPE__BUILDID_DEBUGINFO:
1679 	case DSO_BINARY_TYPE__OPENEMBEDDED_DEBUGINFO:
1680 		return !kmod && dso->kernel == DSO_SPACE__USER;
1681 
1682 	case DSO_BINARY_TYPE__KALLSYMS:
1683 	case DSO_BINARY_TYPE__VMLINUX:
1684 	case DSO_BINARY_TYPE__KCORE:
1685 		return dso->kernel == DSO_SPACE__KERNEL;
1686 
1687 	case DSO_BINARY_TYPE__GUEST_KALLSYMS:
1688 	case DSO_BINARY_TYPE__GUEST_VMLINUX:
1689 	case DSO_BINARY_TYPE__GUEST_KCORE:
1690 		return dso->kernel == DSO_SPACE__KERNEL_GUEST;
1691 
1692 	case DSO_BINARY_TYPE__GUEST_KMODULE:
1693 	case DSO_BINARY_TYPE__GUEST_KMODULE_COMP:
1694 	case DSO_BINARY_TYPE__SYSTEM_PATH_KMODULE:
1695 	case DSO_BINARY_TYPE__SYSTEM_PATH_KMODULE_COMP:
1696 		/*
1697 		 * kernel modules know their symtab type - it's set when
1698 		 * creating a module dso in machine__addnew_module_map().
1699 		 */
1700 		return kmod && dso->symtab_type == type;
1701 
1702 	case DSO_BINARY_TYPE__BUILD_ID_CACHE:
1703 	case DSO_BINARY_TYPE__BUILD_ID_CACHE_DEBUGINFO:
1704 		return true;
1705 
1706 	case DSO_BINARY_TYPE__BPF_PROG_INFO:
1707 	case DSO_BINARY_TYPE__BPF_IMAGE:
1708 	case DSO_BINARY_TYPE__OOL:
1709 	case DSO_BINARY_TYPE__NOT_FOUND:
1710 	default:
1711 		return false;
1712 	}
1713 }
1714 
1715 /* Checks for the existence of the perf-<pid>.map file in two different
1716  * locations.  First, if the process is a separate mount namespace, check in
1717  * that namespace using the pid of the innermost pid namespace.  If's not in a
1718  * namespace, or the file can't be found there, try in the mount namespace of
1719  * the tracing process using our view of its pid.
1720  */
1721 static int dso__find_perf_map(char *filebuf, size_t bufsz,
1722 			      struct nsinfo **nsip)
1723 {
1724 	struct nscookie nsc;
1725 	struct nsinfo *nsi;
1726 	struct nsinfo *nnsi;
1727 	int rc = -1;
1728 
1729 	nsi = *nsip;
1730 
1731 	if (nsi->need_setns) {
1732 		snprintf(filebuf, bufsz, "/tmp/perf-%d.map", nsi->nstgid);
1733 		nsinfo__mountns_enter(nsi, &nsc);
1734 		rc = access(filebuf, R_OK);
1735 		nsinfo__mountns_exit(&nsc);
1736 		if (rc == 0)
1737 			return rc;
1738 	}
1739 
1740 	nnsi = nsinfo__copy(nsi);
1741 	if (nnsi) {
1742 		nsinfo__put(nsi);
1743 
1744 		nnsi->need_setns = false;
1745 		snprintf(filebuf, bufsz, "/tmp/perf-%d.map", nnsi->tgid);
1746 		*nsip = nnsi;
1747 		rc = 0;
1748 	}
1749 
1750 	return rc;
1751 }
1752 
1753 int dso__load(struct dso *dso, struct map *map)
1754 {
1755 	char *name;
1756 	int ret = -1;
1757 	u_int i;
1758 	struct machine *machine = NULL;
1759 	char *root_dir = (char *) "";
1760 	int ss_pos = 0;
1761 	struct symsrc ss_[2];
1762 	struct symsrc *syms_ss = NULL, *runtime_ss = NULL;
1763 	bool kmod;
1764 	bool perfmap;
1765 	struct build_id bid;
1766 	struct nscookie nsc;
1767 	char newmapname[PATH_MAX];
1768 	const char *map_path = dso->long_name;
1769 
1770 	perfmap = strncmp(dso->name, "/tmp/perf-", 10) == 0;
1771 	if (perfmap) {
1772 		if (dso->nsinfo && (dso__find_perf_map(newmapname,
1773 		    sizeof(newmapname), &dso->nsinfo) == 0)) {
1774 			map_path = newmapname;
1775 		}
1776 	}
1777 
1778 	nsinfo__mountns_enter(dso->nsinfo, &nsc);
1779 	pthread_mutex_lock(&dso->lock);
1780 
1781 	/* check again under the dso->lock */
1782 	if (dso__loaded(dso)) {
1783 		ret = 1;
1784 		goto out;
1785 	}
1786 
1787 	kmod = dso->symtab_type == DSO_BINARY_TYPE__SYSTEM_PATH_KMODULE ||
1788 		dso->symtab_type == DSO_BINARY_TYPE__SYSTEM_PATH_KMODULE_COMP ||
1789 		dso->symtab_type == DSO_BINARY_TYPE__GUEST_KMODULE ||
1790 		dso->symtab_type == DSO_BINARY_TYPE__GUEST_KMODULE_COMP;
1791 
1792 	if (dso->kernel && !kmod) {
1793 		if (dso->kernel == DSO_SPACE__KERNEL)
1794 			ret = dso__load_kernel_sym(dso, map);
1795 		else if (dso->kernel == DSO_SPACE__KERNEL_GUEST)
1796 			ret = dso__load_guest_kernel_sym(dso, map);
1797 
1798 		machine = map__kmaps(map)->machine;
1799 		if (machine__is(machine, "x86_64"))
1800 			machine__map_x86_64_entry_trampolines(machine, dso);
1801 		goto out;
1802 	}
1803 
1804 	dso->adjust_symbols = 0;
1805 
1806 	if (perfmap) {
1807 		ret = dso__load_perf_map(map_path, dso);
1808 		dso->symtab_type = ret > 0 ? DSO_BINARY_TYPE__JAVA_JIT :
1809 					     DSO_BINARY_TYPE__NOT_FOUND;
1810 		goto out;
1811 	}
1812 
1813 	if (machine)
1814 		root_dir = machine->root_dir;
1815 
1816 	name = malloc(PATH_MAX);
1817 	if (!name)
1818 		goto out;
1819 
1820 	/*
1821 	 * Read the build id if possible. This is required for
1822 	 * DSO_BINARY_TYPE__BUILDID_DEBUGINFO to work
1823 	 */
1824 	if (!dso->has_build_id &&
1825 	    is_regular_file(dso->long_name)) {
1826 	    __symbol__join_symfs(name, PATH_MAX, dso->long_name);
1827 		if (filename__read_build_id(name, &bid) > 0)
1828 			dso__set_build_id(dso, &bid);
1829 	}
1830 
1831 	/*
1832 	 * Iterate over candidate debug images.
1833 	 * Keep track of "interesting" ones (those which have a symtab, dynsym,
1834 	 * and/or opd section) for processing.
1835 	 */
1836 	for (i = 0; i < DSO_BINARY_TYPE__SYMTAB_CNT; i++) {
1837 		struct symsrc *ss = &ss_[ss_pos];
1838 		bool next_slot = false;
1839 		bool is_reg;
1840 		bool nsexit;
1841 		int bfdrc = -1;
1842 		int sirc = -1;
1843 
1844 		enum dso_binary_type symtab_type = binary_type_symtab[i];
1845 
1846 		nsexit = (symtab_type == DSO_BINARY_TYPE__BUILD_ID_CACHE ||
1847 		    symtab_type == DSO_BINARY_TYPE__BUILD_ID_CACHE_DEBUGINFO);
1848 
1849 		if (!dso__is_compatible_symtab_type(dso, kmod, symtab_type))
1850 			continue;
1851 
1852 		if (dso__read_binary_type_filename(dso, symtab_type,
1853 						   root_dir, name, PATH_MAX))
1854 			continue;
1855 
1856 		if (nsexit)
1857 			nsinfo__mountns_exit(&nsc);
1858 
1859 		is_reg = is_regular_file(name);
1860 #ifdef HAVE_LIBBFD_SUPPORT
1861 		if (is_reg)
1862 			bfdrc = dso__load_bfd_symbols(dso, name);
1863 #endif
1864 		if (is_reg && bfdrc < 0)
1865 			sirc = symsrc__init(ss, dso, name, symtab_type);
1866 
1867 		if (nsexit)
1868 			nsinfo__mountns_enter(dso->nsinfo, &nsc);
1869 
1870 		if (bfdrc == 0) {
1871 			ret = 0;
1872 			break;
1873 		}
1874 
1875 		if (!is_reg || sirc < 0)
1876 			continue;
1877 
1878 		if (!syms_ss && symsrc__has_symtab(ss)) {
1879 			syms_ss = ss;
1880 			next_slot = true;
1881 			if (!dso->symsrc_filename)
1882 				dso->symsrc_filename = strdup(name);
1883 		}
1884 
1885 		if (!runtime_ss && symsrc__possibly_runtime(ss)) {
1886 			runtime_ss = ss;
1887 			next_slot = true;
1888 		}
1889 
1890 		if (next_slot) {
1891 			ss_pos++;
1892 
1893 			if (syms_ss && runtime_ss)
1894 				break;
1895 		} else {
1896 			symsrc__destroy(ss);
1897 		}
1898 
1899 	}
1900 
1901 	if (!runtime_ss && !syms_ss)
1902 		goto out_free;
1903 
1904 	if (runtime_ss && !syms_ss) {
1905 		syms_ss = runtime_ss;
1906 	}
1907 
1908 	/* We'll have to hope for the best */
1909 	if (!runtime_ss && syms_ss)
1910 		runtime_ss = syms_ss;
1911 
1912 	if (syms_ss)
1913 		ret = dso__load_sym(dso, map, syms_ss, runtime_ss, kmod);
1914 	else
1915 		ret = -1;
1916 
1917 	if (ret > 0) {
1918 		int nr_plt;
1919 
1920 		nr_plt = dso__synthesize_plt_symbols(dso, runtime_ss);
1921 		if (nr_plt > 0)
1922 			ret += nr_plt;
1923 	}
1924 
1925 	for (; ss_pos > 0; ss_pos--)
1926 		symsrc__destroy(&ss_[ss_pos - 1]);
1927 out_free:
1928 	free(name);
1929 	if (ret < 0 && strstr(dso->name, " (deleted)") != NULL)
1930 		ret = 0;
1931 out:
1932 	dso__set_loaded(dso);
1933 	pthread_mutex_unlock(&dso->lock);
1934 	nsinfo__mountns_exit(&nsc);
1935 
1936 	return ret;
1937 }
1938 
1939 static int map__strcmp(const void *a, const void *b)
1940 {
1941 	const struct map *ma = *(const struct map **)a, *mb = *(const struct map **)b;
1942 	return strcmp(ma->dso->short_name, mb->dso->short_name);
1943 }
1944 
1945 static int map__strcmp_name(const void *name, const void *b)
1946 {
1947 	const struct map *map = *(const struct map **)b;
1948 	return strcmp(name, map->dso->short_name);
1949 }
1950 
1951 void __maps__sort_by_name(struct maps *maps)
1952 {
1953 	qsort(maps->maps_by_name, maps->nr_maps, sizeof(struct map *), map__strcmp);
1954 }
1955 
1956 static int map__groups__sort_by_name_from_rbtree(struct maps *maps)
1957 {
1958 	struct map *map;
1959 	struct map **maps_by_name = realloc(maps->maps_by_name, maps->nr_maps * sizeof(map));
1960 	int i = 0;
1961 
1962 	if (maps_by_name == NULL)
1963 		return -1;
1964 
1965 	maps->maps_by_name = maps_by_name;
1966 	maps->nr_maps_allocated = maps->nr_maps;
1967 
1968 	maps__for_each_entry(maps, map)
1969 		maps_by_name[i++] = map;
1970 
1971 	__maps__sort_by_name(maps);
1972 	return 0;
1973 }
1974 
1975 static struct map *__maps__find_by_name(struct maps *maps, const char *name)
1976 {
1977 	struct map **mapp;
1978 
1979 	if (maps->maps_by_name == NULL &&
1980 	    map__groups__sort_by_name_from_rbtree(maps))
1981 		return NULL;
1982 
1983 	mapp = bsearch(name, maps->maps_by_name, maps->nr_maps, sizeof(*mapp), map__strcmp_name);
1984 	if (mapp)
1985 		return *mapp;
1986 	return NULL;
1987 }
1988 
1989 struct map *maps__find_by_name(struct maps *maps, const char *name)
1990 {
1991 	struct map *map;
1992 
1993 	down_read(&maps->lock);
1994 
1995 	if (maps->last_search_by_name && strcmp(maps->last_search_by_name->dso->short_name, name) == 0) {
1996 		map = maps->last_search_by_name;
1997 		goto out_unlock;
1998 	}
1999 	/*
2000 	 * If we have maps->maps_by_name, then the name isn't in the rbtree,
2001 	 * as maps->maps_by_name mirrors the rbtree when lookups by name are
2002 	 * made.
2003 	 */
2004 	map = __maps__find_by_name(maps, name);
2005 	if (map || maps->maps_by_name != NULL)
2006 		goto out_unlock;
2007 
2008 	/* Fallback to traversing the rbtree... */
2009 	maps__for_each_entry(maps, map)
2010 		if (strcmp(map->dso->short_name, name) == 0) {
2011 			maps->last_search_by_name = map;
2012 			goto out_unlock;
2013 		}
2014 
2015 	map = NULL;
2016 
2017 out_unlock:
2018 	up_read(&maps->lock);
2019 	return map;
2020 }
2021 
2022 int dso__load_vmlinux(struct dso *dso, struct map *map,
2023 		      const char *vmlinux, bool vmlinux_allocated)
2024 {
2025 	int err = -1;
2026 	struct symsrc ss;
2027 	char symfs_vmlinux[PATH_MAX];
2028 	enum dso_binary_type symtab_type;
2029 
2030 	if (vmlinux[0] == '/')
2031 		snprintf(symfs_vmlinux, sizeof(symfs_vmlinux), "%s", vmlinux);
2032 	else
2033 		symbol__join_symfs(symfs_vmlinux, vmlinux);
2034 
2035 	if (dso->kernel == DSO_SPACE__KERNEL_GUEST)
2036 		symtab_type = DSO_BINARY_TYPE__GUEST_VMLINUX;
2037 	else
2038 		symtab_type = DSO_BINARY_TYPE__VMLINUX;
2039 
2040 	if (symsrc__init(&ss, dso, symfs_vmlinux, symtab_type))
2041 		return -1;
2042 
2043 	err = dso__load_sym(dso, map, &ss, &ss, 0);
2044 	symsrc__destroy(&ss);
2045 
2046 	if (err > 0) {
2047 		if (dso->kernel == DSO_SPACE__KERNEL_GUEST)
2048 			dso->binary_type = DSO_BINARY_TYPE__GUEST_VMLINUX;
2049 		else
2050 			dso->binary_type = DSO_BINARY_TYPE__VMLINUX;
2051 		dso__set_long_name(dso, vmlinux, vmlinux_allocated);
2052 		dso__set_loaded(dso);
2053 		pr_debug("Using %s for symbols\n", symfs_vmlinux);
2054 	}
2055 
2056 	return err;
2057 }
2058 
2059 int dso__load_vmlinux_path(struct dso *dso, struct map *map)
2060 {
2061 	int i, err = 0;
2062 	char *filename = NULL;
2063 
2064 	pr_debug("Looking at the vmlinux_path (%d entries long)\n",
2065 		 vmlinux_path__nr_entries + 1);
2066 
2067 	for (i = 0; i < vmlinux_path__nr_entries; ++i) {
2068 		err = dso__load_vmlinux(dso, map, vmlinux_path[i], false);
2069 		if (err > 0)
2070 			goto out;
2071 	}
2072 
2073 	if (!symbol_conf.ignore_vmlinux_buildid)
2074 		filename = dso__build_id_filename(dso, NULL, 0, false);
2075 	if (filename != NULL) {
2076 		err = dso__load_vmlinux(dso, map, filename, true);
2077 		if (err > 0)
2078 			goto out;
2079 		free(filename);
2080 	}
2081 out:
2082 	return err;
2083 }
2084 
2085 static bool visible_dir_filter(const char *name, struct dirent *d)
2086 {
2087 	if (d->d_type != DT_DIR)
2088 		return false;
2089 	return lsdir_no_dot_filter(name, d);
2090 }
2091 
2092 static int find_matching_kcore(struct map *map, char *dir, size_t dir_sz)
2093 {
2094 	char kallsyms_filename[PATH_MAX];
2095 	int ret = -1;
2096 	struct strlist *dirs;
2097 	struct str_node *nd;
2098 
2099 	dirs = lsdir(dir, visible_dir_filter);
2100 	if (!dirs)
2101 		return -1;
2102 
2103 	strlist__for_each_entry(nd, dirs) {
2104 		scnprintf(kallsyms_filename, sizeof(kallsyms_filename),
2105 			  "%s/%s/kallsyms", dir, nd->s);
2106 		if (!validate_kcore_addresses(kallsyms_filename, map)) {
2107 			strlcpy(dir, kallsyms_filename, dir_sz);
2108 			ret = 0;
2109 			break;
2110 		}
2111 	}
2112 
2113 	strlist__delete(dirs);
2114 
2115 	return ret;
2116 }
2117 
2118 /*
2119  * Use open(O_RDONLY) to check readability directly instead of access(R_OK)
2120  * since access(R_OK) only checks with real UID/GID but open() use effective
2121  * UID/GID and actual capabilities (e.g. /proc/kcore requires CAP_SYS_RAWIO).
2122  */
2123 static bool filename__readable(const char *file)
2124 {
2125 	int fd = open(file, O_RDONLY);
2126 	if (fd < 0)
2127 		return false;
2128 	close(fd);
2129 	return true;
2130 }
2131 
2132 static char *dso__find_kallsyms(struct dso *dso, struct map *map)
2133 {
2134 	struct build_id bid;
2135 	char sbuild_id[SBUILD_ID_SIZE];
2136 	bool is_host = false;
2137 	char path[PATH_MAX];
2138 
2139 	if (!dso->has_build_id) {
2140 		/*
2141 		 * Last resort, if we don't have a build-id and couldn't find
2142 		 * any vmlinux file, try the running kernel kallsyms table.
2143 		 */
2144 		goto proc_kallsyms;
2145 	}
2146 
2147 	if (sysfs__read_build_id("/sys/kernel/notes", &bid) == 0)
2148 		is_host = dso__build_id_equal(dso, &bid);
2149 
2150 	/* Try a fast path for /proc/kallsyms if possible */
2151 	if (is_host) {
2152 		/*
2153 		 * Do not check the build-id cache, unless we know we cannot use
2154 		 * /proc/kcore or module maps don't match to /proc/kallsyms.
2155 		 * To check readability of /proc/kcore, do not use access(R_OK)
2156 		 * since /proc/kcore requires CAP_SYS_RAWIO to read and access
2157 		 * can't check it.
2158 		 */
2159 		if (filename__readable("/proc/kcore") &&
2160 		    !validate_kcore_addresses("/proc/kallsyms", map))
2161 			goto proc_kallsyms;
2162 	}
2163 
2164 	build_id__sprintf(&dso->bid, sbuild_id);
2165 
2166 	/* Find kallsyms in build-id cache with kcore */
2167 	scnprintf(path, sizeof(path), "%s/%s/%s",
2168 		  buildid_dir, DSO__NAME_KCORE, sbuild_id);
2169 
2170 	if (!find_matching_kcore(map, path, sizeof(path)))
2171 		return strdup(path);
2172 
2173 	/* Use current /proc/kallsyms if possible */
2174 	if (is_host) {
2175 proc_kallsyms:
2176 		return strdup("/proc/kallsyms");
2177 	}
2178 
2179 	/* Finally, find a cache of kallsyms */
2180 	if (!build_id_cache__kallsyms_path(sbuild_id, path, sizeof(path))) {
2181 		pr_err("No kallsyms or vmlinux with build-id %s was found\n",
2182 		       sbuild_id);
2183 		return NULL;
2184 	}
2185 
2186 	return strdup(path);
2187 }
2188 
2189 static int dso__load_kernel_sym(struct dso *dso, struct map *map)
2190 {
2191 	int err;
2192 	const char *kallsyms_filename = NULL;
2193 	char *kallsyms_allocated_filename = NULL;
2194 	char *filename = NULL;
2195 
2196 	/*
2197 	 * Step 1: if the user specified a kallsyms or vmlinux filename, use
2198 	 * it and only it, reporting errors to the user if it cannot be used.
2199 	 *
2200 	 * For instance, try to analyse an ARM perf.data file _without_ a
2201 	 * build-id, or if the user specifies the wrong path to the right
2202 	 * vmlinux file, obviously we can't fallback to another vmlinux (a
2203 	 * x86_86 one, on the machine where analysis is being performed, say),
2204 	 * or worse, /proc/kallsyms.
2205 	 *
2206 	 * If the specified file _has_ a build-id and there is a build-id
2207 	 * section in the perf.data file, we will still do the expected
2208 	 * validation in dso__load_vmlinux and will bail out if they don't
2209 	 * match.
2210 	 */
2211 	if (symbol_conf.kallsyms_name != NULL) {
2212 		kallsyms_filename = symbol_conf.kallsyms_name;
2213 		goto do_kallsyms;
2214 	}
2215 
2216 	if (!symbol_conf.ignore_vmlinux && symbol_conf.vmlinux_name != NULL) {
2217 		return dso__load_vmlinux(dso, map, symbol_conf.vmlinux_name, false);
2218 	}
2219 
2220 	/*
2221 	 * Before checking on common vmlinux locations, check if it's
2222 	 * stored as standard build id binary (not kallsyms) under
2223 	 * .debug cache.
2224 	 */
2225 	if (!symbol_conf.ignore_vmlinux_buildid)
2226 		filename = __dso__build_id_filename(dso, NULL, 0, false, false);
2227 	if (filename != NULL) {
2228 		err = dso__load_vmlinux(dso, map, filename, true);
2229 		if (err > 0)
2230 			return err;
2231 		free(filename);
2232 	}
2233 
2234 	if (!symbol_conf.ignore_vmlinux && vmlinux_path != NULL) {
2235 		err = dso__load_vmlinux_path(dso, map);
2236 		if (err > 0)
2237 			return err;
2238 	}
2239 
2240 	/* do not try local files if a symfs was given */
2241 	if (symbol_conf.symfs[0] != 0)
2242 		return -1;
2243 
2244 	kallsyms_allocated_filename = dso__find_kallsyms(dso, map);
2245 	if (!kallsyms_allocated_filename)
2246 		return -1;
2247 
2248 	kallsyms_filename = kallsyms_allocated_filename;
2249 
2250 do_kallsyms:
2251 	err = dso__load_kallsyms(dso, kallsyms_filename, map);
2252 	if (err > 0)
2253 		pr_debug("Using %s for symbols\n", kallsyms_filename);
2254 	free(kallsyms_allocated_filename);
2255 
2256 	if (err > 0 && !dso__is_kcore(dso)) {
2257 		dso->binary_type = DSO_BINARY_TYPE__KALLSYMS;
2258 		dso__set_long_name(dso, DSO__NAME_KALLSYMS, false);
2259 		map__fixup_start(map);
2260 		map__fixup_end(map);
2261 	}
2262 
2263 	return err;
2264 }
2265 
2266 static int dso__load_guest_kernel_sym(struct dso *dso, struct map *map)
2267 {
2268 	int err;
2269 	const char *kallsyms_filename = NULL;
2270 	struct machine *machine = map__kmaps(map)->machine;
2271 	char path[PATH_MAX];
2272 
2273 	if (machine__is_default_guest(machine)) {
2274 		/*
2275 		 * if the user specified a vmlinux filename, use it and only
2276 		 * it, reporting errors to the user if it cannot be used.
2277 		 * Or use file guest_kallsyms inputted by user on commandline
2278 		 */
2279 		if (symbol_conf.default_guest_vmlinux_name != NULL) {
2280 			err = dso__load_vmlinux(dso, map,
2281 						symbol_conf.default_guest_vmlinux_name,
2282 						false);
2283 			return err;
2284 		}
2285 
2286 		kallsyms_filename = symbol_conf.default_guest_kallsyms;
2287 		if (!kallsyms_filename)
2288 			return -1;
2289 	} else {
2290 		sprintf(path, "%s/proc/kallsyms", machine->root_dir);
2291 		kallsyms_filename = path;
2292 	}
2293 
2294 	err = dso__load_kallsyms(dso, kallsyms_filename, map);
2295 	if (err > 0)
2296 		pr_debug("Using %s for symbols\n", kallsyms_filename);
2297 	if (err > 0 && !dso__is_kcore(dso)) {
2298 		dso->binary_type = DSO_BINARY_TYPE__GUEST_KALLSYMS;
2299 		dso__set_long_name(dso, machine->mmap_name, false);
2300 		map__fixup_start(map);
2301 		map__fixup_end(map);
2302 	}
2303 
2304 	return err;
2305 }
2306 
2307 static void vmlinux_path__exit(void)
2308 {
2309 	while (--vmlinux_path__nr_entries >= 0)
2310 		zfree(&vmlinux_path[vmlinux_path__nr_entries]);
2311 	vmlinux_path__nr_entries = 0;
2312 
2313 	zfree(&vmlinux_path);
2314 }
2315 
2316 static const char * const vmlinux_paths[] = {
2317 	"vmlinux",
2318 	"/boot/vmlinux"
2319 };
2320 
2321 static const char * const vmlinux_paths_upd[] = {
2322 	"/boot/vmlinux-%s",
2323 	"/usr/lib/debug/boot/vmlinux-%s",
2324 	"/lib/modules/%s/build/vmlinux",
2325 	"/usr/lib/debug/lib/modules/%s/vmlinux",
2326 	"/usr/lib/debug/boot/vmlinux-%s.debug"
2327 };
2328 
2329 static int vmlinux_path__add(const char *new_entry)
2330 {
2331 	vmlinux_path[vmlinux_path__nr_entries] = strdup(new_entry);
2332 	if (vmlinux_path[vmlinux_path__nr_entries] == NULL)
2333 		return -1;
2334 	++vmlinux_path__nr_entries;
2335 
2336 	return 0;
2337 }
2338 
2339 static int vmlinux_path__init(struct perf_env *env)
2340 {
2341 	struct utsname uts;
2342 	char bf[PATH_MAX];
2343 	char *kernel_version;
2344 	unsigned int i;
2345 
2346 	vmlinux_path = malloc(sizeof(char *) * (ARRAY_SIZE(vmlinux_paths) +
2347 			      ARRAY_SIZE(vmlinux_paths_upd)));
2348 	if (vmlinux_path == NULL)
2349 		return -1;
2350 
2351 	for (i = 0; i < ARRAY_SIZE(vmlinux_paths); i++)
2352 		if (vmlinux_path__add(vmlinux_paths[i]) < 0)
2353 			goto out_fail;
2354 
2355 	/* only try kernel version if no symfs was given */
2356 	if (symbol_conf.symfs[0] != 0)
2357 		return 0;
2358 
2359 	if (env) {
2360 		kernel_version = env->os_release;
2361 	} else {
2362 		if (uname(&uts) < 0)
2363 			goto out_fail;
2364 
2365 		kernel_version = uts.release;
2366 	}
2367 
2368 	for (i = 0; i < ARRAY_SIZE(vmlinux_paths_upd); i++) {
2369 		snprintf(bf, sizeof(bf), vmlinux_paths_upd[i], kernel_version);
2370 		if (vmlinux_path__add(bf) < 0)
2371 			goto out_fail;
2372 	}
2373 
2374 	return 0;
2375 
2376 out_fail:
2377 	vmlinux_path__exit();
2378 	return -1;
2379 }
2380 
2381 int setup_list(struct strlist **list, const char *list_str,
2382 		      const char *list_name)
2383 {
2384 	if (list_str == NULL)
2385 		return 0;
2386 
2387 	*list = strlist__new(list_str, NULL);
2388 	if (!*list) {
2389 		pr_err("problems parsing %s list\n", list_name);
2390 		return -1;
2391 	}
2392 
2393 	symbol_conf.has_filter = true;
2394 	return 0;
2395 }
2396 
2397 int setup_intlist(struct intlist **list, const char *list_str,
2398 		  const char *list_name)
2399 {
2400 	if (list_str == NULL)
2401 		return 0;
2402 
2403 	*list = intlist__new(list_str);
2404 	if (!*list) {
2405 		pr_err("problems parsing %s list\n", list_name);
2406 		return -1;
2407 	}
2408 	return 0;
2409 }
2410 
2411 static int setup_addrlist(struct intlist **addr_list, struct strlist *sym_list)
2412 {
2413 	struct str_node *pos, *tmp;
2414 	unsigned long val;
2415 	char *sep;
2416 	const char *end;
2417 	int i = 0, err;
2418 
2419 	*addr_list = intlist__new(NULL);
2420 	if (!*addr_list)
2421 		return -1;
2422 
2423 	strlist__for_each_entry_safe(pos, tmp, sym_list) {
2424 		errno = 0;
2425 		val = strtoul(pos->s, &sep, 16);
2426 		if (errno || (sep == pos->s))
2427 			continue;
2428 
2429 		if (*sep != '\0') {
2430 			end = pos->s + strlen(pos->s) - 1;
2431 			while (end >= sep && isspace(*end))
2432 				end--;
2433 
2434 			if (end >= sep)
2435 				continue;
2436 		}
2437 
2438 		err = intlist__add(*addr_list, val);
2439 		if (err)
2440 			break;
2441 
2442 		strlist__remove(sym_list, pos);
2443 		i++;
2444 	}
2445 
2446 	if (i == 0) {
2447 		intlist__delete(*addr_list);
2448 		*addr_list = NULL;
2449 	}
2450 
2451 	return 0;
2452 }
2453 
2454 static bool symbol__read_kptr_restrict(void)
2455 {
2456 	bool value = false;
2457 	FILE *fp = fopen("/proc/sys/kernel/kptr_restrict", "r");
2458 
2459 	if (fp != NULL) {
2460 		char line[8];
2461 
2462 		if (fgets(line, sizeof(line), fp) != NULL)
2463 			value = perf_cap__capable(CAP_SYSLOG) ?
2464 					(atoi(line) >= 2) :
2465 					(atoi(line) != 0);
2466 
2467 		fclose(fp);
2468 	}
2469 
2470 	/* Per kernel/kallsyms.c:
2471 	 * we also restrict when perf_event_paranoid > 1 w/o CAP_SYSLOG
2472 	 */
2473 	if (perf_event_paranoid() > 1 && !perf_cap__capable(CAP_SYSLOG))
2474 		value = true;
2475 
2476 	return value;
2477 }
2478 
2479 int symbol__annotation_init(void)
2480 {
2481 	if (symbol_conf.init_annotation)
2482 		return 0;
2483 
2484 	if (symbol_conf.initialized) {
2485 		pr_err("Annotation needs to be init before symbol__init()\n");
2486 		return -1;
2487 	}
2488 
2489 	symbol_conf.priv_size += sizeof(struct annotation);
2490 	symbol_conf.init_annotation = true;
2491 	return 0;
2492 }
2493 
2494 int symbol__init(struct perf_env *env)
2495 {
2496 	const char *symfs;
2497 
2498 	if (symbol_conf.initialized)
2499 		return 0;
2500 
2501 	symbol_conf.priv_size = PERF_ALIGN(symbol_conf.priv_size, sizeof(u64));
2502 
2503 	symbol__elf_init();
2504 
2505 	if (symbol_conf.sort_by_name)
2506 		symbol_conf.priv_size += (sizeof(struct symbol_name_rb_node) -
2507 					  sizeof(struct symbol));
2508 
2509 	if (symbol_conf.try_vmlinux_path && vmlinux_path__init(env) < 0)
2510 		return -1;
2511 
2512 	if (symbol_conf.field_sep && *symbol_conf.field_sep == '.') {
2513 		pr_err("'.' is the only non valid --field-separator argument\n");
2514 		return -1;
2515 	}
2516 
2517 	if (setup_list(&symbol_conf.dso_list,
2518 		       symbol_conf.dso_list_str, "dso") < 0)
2519 		return -1;
2520 
2521 	if (setup_list(&symbol_conf.comm_list,
2522 		       symbol_conf.comm_list_str, "comm") < 0)
2523 		goto out_free_dso_list;
2524 
2525 	if (setup_intlist(&symbol_conf.pid_list,
2526 		       symbol_conf.pid_list_str, "pid") < 0)
2527 		goto out_free_comm_list;
2528 
2529 	if (setup_intlist(&symbol_conf.tid_list,
2530 		       symbol_conf.tid_list_str, "tid") < 0)
2531 		goto out_free_pid_list;
2532 
2533 	if (setup_list(&symbol_conf.sym_list,
2534 		       symbol_conf.sym_list_str, "symbol") < 0)
2535 		goto out_free_tid_list;
2536 
2537 	if (symbol_conf.sym_list &&
2538 	    setup_addrlist(&symbol_conf.addr_list, symbol_conf.sym_list) < 0)
2539 		goto out_free_sym_list;
2540 
2541 	if (setup_list(&symbol_conf.bt_stop_list,
2542 		       symbol_conf.bt_stop_list_str, "symbol") < 0)
2543 		goto out_free_sym_list;
2544 
2545 	/*
2546 	 * A path to symbols of "/" is identical to ""
2547 	 * reset here for simplicity.
2548 	 */
2549 	symfs = realpath(symbol_conf.symfs, NULL);
2550 	if (symfs == NULL)
2551 		symfs = symbol_conf.symfs;
2552 	if (strcmp(symfs, "/") == 0)
2553 		symbol_conf.symfs = "";
2554 	if (symfs != symbol_conf.symfs)
2555 		free((void *)symfs);
2556 
2557 	symbol_conf.kptr_restrict = symbol__read_kptr_restrict();
2558 
2559 	symbol_conf.initialized = true;
2560 	return 0;
2561 
2562 out_free_sym_list:
2563 	strlist__delete(symbol_conf.sym_list);
2564 	intlist__delete(symbol_conf.addr_list);
2565 out_free_tid_list:
2566 	intlist__delete(symbol_conf.tid_list);
2567 out_free_pid_list:
2568 	intlist__delete(symbol_conf.pid_list);
2569 out_free_comm_list:
2570 	strlist__delete(symbol_conf.comm_list);
2571 out_free_dso_list:
2572 	strlist__delete(symbol_conf.dso_list);
2573 	return -1;
2574 }
2575 
2576 void symbol__exit(void)
2577 {
2578 	if (!symbol_conf.initialized)
2579 		return;
2580 	strlist__delete(symbol_conf.bt_stop_list);
2581 	strlist__delete(symbol_conf.sym_list);
2582 	strlist__delete(symbol_conf.dso_list);
2583 	strlist__delete(symbol_conf.comm_list);
2584 	intlist__delete(symbol_conf.tid_list);
2585 	intlist__delete(symbol_conf.pid_list);
2586 	intlist__delete(symbol_conf.addr_list);
2587 	vmlinux_path__exit();
2588 	symbol_conf.sym_list = symbol_conf.dso_list = symbol_conf.comm_list = NULL;
2589 	symbol_conf.bt_stop_list = NULL;
2590 	symbol_conf.initialized = false;
2591 }
2592 
2593 int symbol__config_symfs(const struct option *opt __maybe_unused,
2594 			 const char *dir, int unset __maybe_unused)
2595 {
2596 	char *bf = NULL;
2597 	int ret;
2598 
2599 	symbol_conf.symfs = strdup(dir);
2600 	if (symbol_conf.symfs == NULL)
2601 		return -ENOMEM;
2602 
2603 	/* skip the locally configured cache if a symfs is given, and
2604 	 * config buildid dir to symfs/.debug
2605 	 */
2606 	ret = asprintf(&bf, "%s/%s", dir, ".debug");
2607 	if (ret < 0)
2608 		return -ENOMEM;
2609 
2610 	set_buildid_dir(bf);
2611 
2612 	free(bf);
2613 	return 0;
2614 }
2615 
2616 struct mem_info *mem_info__get(struct mem_info *mi)
2617 {
2618 	if (mi)
2619 		refcount_inc(&mi->refcnt);
2620 	return mi;
2621 }
2622 
2623 void mem_info__put(struct mem_info *mi)
2624 {
2625 	if (mi && refcount_dec_and_test(&mi->refcnt))
2626 		free(mi);
2627 }
2628 
2629 struct mem_info *mem_info__new(void)
2630 {
2631 	struct mem_info *mi = zalloc(sizeof(*mi));
2632 
2633 	if (mi)
2634 		refcount_set(&mi->refcnt, 1);
2635 	return mi;
2636 }
2637 
2638 /*
2639  * Checks that user supplied symbol kernel files are accessible because
2640  * the default mechanism for accessing elf files fails silently. i.e. if
2641  * debug syms for a build ID aren't found perf carries on normally. When
2642  * they are user supplied we should assume that the user doesn't want to
2643  * silently fail.
2644  */
2645 int symbol__validate_sym_arguments(void)
2646 {
2647 	if (symbol_conf.vmlinux_name &&
2648 	    access(symbol_conf.vmlinux_name, R_OK)) {
2649 		pr_err("Invalid file: %s\n", symbol_conf.vmlinux_name);
2650 		return -EINVAL;
2651 	}
2652 	if (symbol_conf.kallsyms_name &&
2653 	    access(symbol_conf.kallsyms_name, R_OK)) {
2654 		pr_err("Invalid file: %s\n", symbol_conf.kallsyms_name);
2655 		return -EINVAL;
2656 	}
2657 	return 0;
2658 }
2659