xref: /linux/tools/perf/util/symbol.c (revision 486021e04b24f8dffe54ec282ce5d4cc3e71133f)
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 map_list_node {
52 	struct list_head node;
53 	struct map *map;
54 };
55 
56 struct symbol_conf symbol_conf = {
57 	.nanosecs		= false,
58 	.use_modules		= true,
59 	.try_vmlinux_path	= true,
60 	.demangle		= true,
61 	.demangle_kernel	= false,
62 	.cumulate_callchain	= true,
63 	.time_quantum		= 100 * NSEC_PER_MSEC, /* 100ms */
64 	.show_hist_headers	= true,
65 	.symfs			= "",
66 	.event_group		= true,
67 	.inline_name		= true,
68 	.res_sample		= 0,
69 };
70 
71 static enum dso_binary_type binary_type_symtab[] = {
72 	DSO_BINARY_TYPE__KALLSYMS,
73 	DSO_BINARY_TYPE__GUEST_KALLSYMS,
74 	DSO_BINARY_TYPE__JAVA_JIT,
75 	DSO_BINARY_TYPE__DEBUGLINK,
76 	DSO_BINARY_TYPE__BUILD_ID_CACHE,
77 	DSO_BINARY_TYPE__BUILD_ID_CACHE_DEBUGINFO,
78 	DSO_BINARY_TYPE__FEDORA_DEBUGINFO,
79 	DSO_BINARY_TYPE__UBUNTU_DEBUGINFO,
80 	DSO_BINARY_TYPE__BUILDID_DEBUGINFO,
81 	DSO_BINARY_TYPE__SYSTEM_PATH_DSO,
82 	DSO_BINARY_TYPE__GUEST_KMODULE,
83 	DSO_BINARY_TYPE__GUEST_KMODULE_COMP,
84 	DSO_BINARY_TYPE__SYSTEM_PATH_KMODULE,
85 	DSO_BINARY_TYPE__SYSTEM_PATH_KMODULE_COMP,
86 	DSO_BINARY_TYPE__OPENEMBEDDED_DEBUGINFO,
87 	DSO_BINARY_TYPE__MIXEDUP_UBUNTU_DEBUGINFO,
88 	DSO_BINARY_TYPE__NOT_FOUND,
89 };
90 
91 #define DSO_BINARY_TYPE__SYMTAB_CNT ARRAY_SIZE(binary_type_symtab)
92 
93 static struct map_list_node *map_list_node__new(void)
94 {
95 	return malloc(sizeof(struct map_list_node));
96 }
97 
98 static bool symbol_type__filter(char symbol_type)
99 {
100 	symbol_type = toupper(symbol_type);
101 	return symbol_type == 'T' || symbol_type == 'W' || symbol_type == 'D' || symbol_type == 'B';
102 }
103 
104 static int prefix_underscores_count(const char *str)
105 {
106 	const char *tail = str;
107 
108 	while (*tail == '_')
109 		tail++;
110 
111 	return tail - str;
112 }
113 
114 const char * __weak arch__normalize_symbol_name(const char *name)
115 {
116 	return name;
117 }
118 
119 int __weak arch__compare_symbol_names(const char *namea, const char *nameb)
120 {
121 	return strcmp(namea, nameb);
122 }
123 
124 int __weak arch__compare_symbol_names_n(const char *namea, const char *nameb,
125 					unsigned int n)
126 {
127 	return strncmp(namea, nameb, n);
128 }
129 
130 int __weak arch__choose_best_symbol(struct symbol *syma,
131 				    struct symbol *symb __maybe_unused)
132 {
133 	/* Avoid "SyS" kernel syscall aliases */
134 	if (strlen(syma->name) >= 3 && !strncmp(syma->name, "SyS", 3))
135 		return SYMBOL_B;
136 	if (strlen(syma->name) >= 10 && !strncmp(syma->name, "compat_SyS", 10))
137 		return SYMBOL_B;
138 
139 	return SYMBOL_A;
140 }
141 
142 static int choose_best_symbol(struct symbol *syma, struct symbol *symb)
143 {
144 	s64 a;
145 	s64 b;
146 	size_t na, nb;
147 
148 	/* Prefer a symbol with non zero length */
149 	a = syma->end - syma->start;
150 	b = symb->end - symb->start;
151 	if ((b == 0) && (a > 0))
152 		return SYMBOL_A;
153 	else if ((a == 0) && (b > 0))
154 		return SYMBOL_B;
155 
156 	/* Prefer a non weak symbol over a weak one */
157 	a = syma->binding == STB_WEAK;
158 	b = symb->binding == STB_WEAK;
159 	if (b && !a)
160 		return SYMBOL_A;
161 	if (a && !b)
162 		return SYMBOL_B;
163 
164 	/* Prefer a global symbol over a non global one */
165 	a = syma->binding == STB_GLOBAL;
166 	b = symb->binding == STB_GLOBAL;
167 	if (a && !b)
168 		return SYMBOL_A;
169 	if (b && !a)
170 		return SYMBOL_B;
171 
172 	/* Prefer a symbol with less underscores */
173 	a = prefix_underscores_count(syma->name);
174 	b = prefix_underscores_count(symb->name);
175 	if (b > a)
176 		return SYMBOL_A;
177 	else if (a > b)
178 		return SYMBOL_B;
179 
180 	/* Choose the symbol with the longest name */
181 	na = strlen(syma->name);
182 	nb = strlen(symb->name);
183 	if (na > nb)
184 		return SYMBOL_A;
185 	else if (na < nb)
186 		return SYMBOL_B;
187 
188 	return arch__choose_best_symbol(syma, symb);
189 }
190 
191 void symbols__fixup_duplicate(struct rb_root_cached *symbols)
192 {
193 	struct rb_node *nd;
194 	struct symbol *curr, *next;
195 
196 	if (symbol_conf.allow_aliases)
197 		return;
198 
199 	nd = rb_first_cached(symbols);
200 
201 	while (nd) {
202 		curr = rb_entry(nd, struct symbol, rb_node);
203 again:
204 		nd = rb_next(&curr->rb_node);
205 		if (!nd)
206 			break;
207 
208 		next = rb_entry(nd, struct symbol, rb_node);
209 		if (curr->start != next->start)
210 			continue;
211 
212 		if (choose_best_symbol(curr, next) == SYMBOL_A) {
213 			if (next->type == STT_GNU_IFUNC)
214 				curr->ifunc_alias = true;
215 			rb_erase_cached(&next->rb_node, symbols);
216 			symbol__delete(next);
217 			goto again;
218 		} else {
219 			if (curr->type == STT_GNU_IFUNC)
220 				next->ifunc_alias = true;
221 			nd = rb_next(&curr->rb_node);
222 			rb_erase_cached(&curr->rb_node, symbols);
223 			symbol__delete(curr);
224 		}
225 	}
226 }
227 
228 /* Update zero-sized symbols using the address of the next symbol */
229 void symbols__fixup_end(struct rb_root_cached *symbols, bool is_kallsyms)
230 {
231 	struct rb_node *nd, *prevnd = rb_first_cached(symbols);
232 	struct symbol *curr, *prev;
233 
234 	if (prevnd == NULL)
235 		return;
236 
237 	curr = rb_entry(prevnd, struct symbol, rb_node);
238 
239 	for (nd = rb_next(prevnd); nd; nd = rb_next(nd)) {
240 		prev = curr;
241 		curr = rb_entry(nd, struct symbol, rb_node);
242 
243 		/*
244 		 * On some architecture kernel text segment start is located at
245 		 * some low memory address, while modules are located at high
246 		 * memory addresses (or vice versa).  The gap between end of
247 		 * kernel text segment and beginning of first module's text
248 		 * segment is very big.  Therefore do not fill this gap and do
249 		 * not assign it to the kernel dso map (kallsyms).
250 		 *
251 		 * In kallsyms, it determines module symbols using '[' character
252 		 * like in:
253 		 *   ffffffffc1937000 T hdmi_driver_init  [snd_hda_codec_hdmi]
254 		 */
255 		if (prev->end == prev->start) {
256 			/* Last kernel/module symbol mapped to end of page */
257 			if (is_kallsyms && (!strchr(prev->name, '[') !=
258 					    !strchr(curr->name, '[')))
259 				prev->end = roundup(prev->end + 4096, 4096);
260 			else
261 				prev->end = curr->start;
262 
263 			pr_debug4("%s sym:%s end:%#" PRIx64 "\n",
264 				  __func__, prev->name, prev->end);
265 		}
266 	}
267 
268 	/* Last entry */
269 	if (curr->end == curr->start)
270 		curr->end = roundup(curr->start, 4096) + 4096;
271 }
272 
273 void maps__fixup_end(struct maps *maps)
274 {
275 	struct map_rb_node *prev = NULL, *curr;
276 
277 	down_write(maps__lock(maps));
278 
279 	maps__for_each_entry(maps, curr) {
280 		if (prev != NULL && !map__end(prev->map))
281 			map__set_end(prev->map, map__start(curr->map));
282 
283 		prev = curr;
284 	}
285 
286 	/*
287 	 * We still haven't the actual symbols, so guess the
288 	 * last map final address.
289 	 */
290 	if (curr && !map__end(curr->map))
291 		map__set_end(curr->map, ~0ULL);
292 
293 	up_write(maps__lock(maps));
294 }
295 
296 struct symbol *symbol__new(u64 start, u64 len, u8 binding, u8 type, const char *name)
297 {
298 	size_t namelen = strlen(name) + 1;
299 	struct symbol *sym = calloc(1, (symbol_conf.priv_size +
300 					sizeof(*sym) + namelen));
301 	if (sym == NULL)
302 		return NULL;
303 
304 	if (symbol_conf.priv_size) {
305 		if (symbol_conf.init_annotation) {
306 			struct annotation *notes = (void *)sym;
307 			annotation__init(notes);
308 		}
309 		sym = ((void *)sym) + symbol_conf.priv_size;
310 	}
311 
312 	sym->start   = start;
313 	sym->end     = len ? start + len : start;
314 	sym->type    = type;
315 	sym->binding = binding;
316 	sym->namelen = namelen - 1;
317 
318 	pr_debug4("%s: %s %#" PRIx64 "-%#" PRIx64 "\n",
319 		  __func__, name, start, sym->end);
320 	memcpy(sym->name, name, namelen);
321 
322 	return sym;
323 }
324 
325 void symbol__delete(struct symbol *sym)
326 {
327 	if (symbol_conf.priv_size) {
328 		if (symbol_conf.init_annotation) {
329 			struct annotation *notes = symbol__annotation(sym);
330 
331 			annotation__exit(notes);
332 		}
333 	}
334 	free(((void *)sym) - symbol_conf.priv_size);
335 }
336 
337 void symbols__delete(struct rb_root_cached *symbols)
338 {
339 	struct symbol *pos;
340 	struct rb_node *next = rb_first_cached(symbols);
341 
342 	while (next) {
343 		pos = rb_entry(next, struct symbol, rb_node);
344 		next = rb_next(&pos->rb_node);
345 		rb_erase_cached(&pos->rb_node, symbols);
346 		symbol__delete(pos);
347 	}
348 }
349 
350 void __symbols__insert(struct rb_root_cached *symbols,
351 		       struct symbol *sym, bool kernel)
352 {
353 	struct rb_node **p = &symbols->rb_root.rb_node;
354 	struct rb_node *parent = NULL;
355 	const u64 ip = sym->start;
356 	struct symbol *s;
357 	bool leftmost = true;
358 
359 	if (kernel) {
360 		const char *name = sym->name;
361 		/*
362 		 * ppc64 uses function descriptors and appends a '.' to the
363 		 * start of every instruction address. Remove it.
364 		 */
365 		if (name[0] == '.')
366 			name++;
367 		sym->idle = symbol__is_idle(name);
368 	}
369 
370 	while (*p != NULL) {
371 		parent = *p;
372 		s = rb_entry(parent, struct symbol, rb_node);
373 		if (ip < s->start)
374 			p = &(*p)->rb_left;
375 		else {
376 			p = &(*p)->rb_right;
377 			leftmost = false;
378 		}
379 	}
380 	rb_link_node(&sym->rb_node, parent, p);
381 	rb_insert_color_cached(&sym->rb_node, symbols, leftmost);
382 }
383 
384 void symbols__insert(struct rb_root_cached *symbols, struct symbol *sym)
385 {
386 	__symbols__insert(symbols, sym, false);
387 }
388 
389 static struct symbol *symbols__find(struct rb_root_cached *symbols, u64 ip)
390 {
391 	struct rb_node *n;
392 
393 	if (symbols == NULL)
394 		return NULL;
395 
396 	n = symbols->rb_root.rb_node;
397 
398 	while (n) {
399 		struct symbol *s = rb_entry(n, struct symbol, rb_node);
400 
401 		if (ip < s->start)
402 			n = n->rb_left;
403 		else if (ip > s->end || (ip == s->end && ip != s->start))
404 			n = n->rb_right;
405 		else
406 			return s;
407 	}
408 
409 	return NULL;
410 }
411 
412 static struct symbol *symbols__first(struct rb_root_cached *symbols)
413 {
414 	struct rb_node *n = rb_first_cached(symbols);
415 
416 	if (n)
417 		return rb_entry(n, struct symbol, rb_node);
418 
419 	return NULL;
420 }
421 
422 static struct symbol *symbols__last(struct rb_root_cached *symbols)
423 {
424 	struct rb_node *n = rb_last(&symbols->rb_root);
425 
426 	if (n)
427 		return rb_entry(n, struct symbol, rb_node);
428 
429 	return NULL;
430 }
431 
432 static struct symbol *symbols__next(struct symbol *sym)
433 {
434 	struct rb_node *n = rb_next(&sym->rb_node);
435 
436 	if (n)
437 		return rb_entry(n, struct symbol, rb_node);
438 
439 	return NULL;
440 }
441 
442 static int symbols__sort_name_cmp(const void *vlhs, const void *vrhs)
443 {
444 	const struct symbol *lhs = *((const struct symbol **)vlhs);
445 	const struct symbol *rhs = *((const struct symbol **)vrhs);
446 
447 	return strcmp(lhs->name, rhs->name);
448 }
449 
450 static struct symbol **symbols__sort_by_name(struct rb_root_cached *source, size_t *len)
451 {
452 	struct rb_node *nd;
453 	struct symbol **result;
454 	size_t i = 0, size = 0;
455 
456 	for (nd = rb_first_cached(source); nd; nd = rb_next(nd))
457 		size++;
458 
459 	result = malloc(sizeof(*result) * size);
460 	if (!result)
461 		return NULL;
462 
463 	for (nd = rb_first_cached(source); nd; nd = rb_next(nd)) {
464 		struct symbol *pos = rb_entry(nd, struct symbol, rb_node);
465 
466 		result[i++] = pos;
467 	}
468 	qsort(result, size, sizeof(*result), symbols__sort_name_cmp);
469 	*len = size;
470 	return result;
471 }
472 
473 int symbol__match_symbol_name(const char *name, const char *str,
474 			      enum symbol_tag_include includes)
475 {
476 	const char *versioning;
477 
478 	if (includes == SYMBOL_TAG_INCLUDE__DEFAULT_ONLY &&
479 	    (versioning = strstr(name, "@@"))) {
480 		int len = strlen(str);
481 
482 		if (len < versioning - name)
483 			len = versioning - name;
484 
485 		return arch__compare_symbol_names_n(name, str, len);
486 	} else
487 		return arch__compare_symbol_names(name, str);
488 }
489 
490 static struct symbol *symbols__find_by_name(struct symbol *symbols[],
491 					    size_t symbols_len,
492 					    const char *name,
493 					    enum symbol_tag_include includes,
494 					    size_t *found_idx)
495 {
496 	size_t i, lower = 0, upper = symbols_len;
497 	struct symbol *s = NULL;
498 
499 	if (found_idx)
500 		*found_idx = SIZE_MAX;
501 
502 	if (!symbols_len)
503 		return NULL;
504 
505 	while (lower < upper) {
506 		int cmp;
507 
508 		i = (lower + upper) / 2;
509 		cmp = symbol__match_symbol_name(symbols[i]->name, name, includes);
510 
511 		if (cmp > 0)
512 			upper = i;
513 		else if (cmp < 0)
514 			lower = i + 1;
515 		else {
516 			if (found_idx)
517 				*found_idx = i;
518 			s = symbols[i];
519 			break;
520 		}
521 	}
522 	if (s && includes != SYMBOL_TAG_INCLUDE__DEFAULT_ONLY) {
523 		/* return first symbol that has same name (if any) */
524 		for (; i > 0; i--) {
525 			struct symbol *tmp = symbols[i - 1];
526 
527 			if (!arch__compare_symbol_names(tmp->name, s->name)) {
528 				if (found_idx)
529 					*found_idx = i - 1;
530 				s = tmp;
531 			} else
532 				break;
533 		}
534 	}
535 	assert(!found_idx || !s || s == symbols[*found_idx]);
536 	return s;
537 }
538 
539 void dso__reset_find_symbol_cache(struct dso *dso)
540 {
541 	dso->last_find_result.addr   = 0;
542 	dso->last_find_result.symbol = NULL;
543 }
544 
545 void dso__insert_symbol(struct dso *dso, struct symbol *sym)
546 {
547 	__symbols__insert(&dso->symbols, sym, dso->kernel);
548 
549 	/* update the symbol cache if necessary */
550 	if (dso->last_find_result.addr >= sym->start &&
551 	    (dso->last_find_result.addr < sym->end ||
552 	    sym->start == sym->end)) {
553 		dso->last_find_result.symbol = sym;
554 	}
555 }
556 
557 void dso__delete_symbol(struct dso *dso, struct symbol *sym)
558 {
559 	rb_erase_cached(&sym->rb_node, &dso->symbols);
560 	symbol__delete(sym);
561 	dso__reset_find_symbol_cache(dso);
562 }
563 
564 struct symbol *dso__find_symbol(struct dso *dso, u64 addr)
565 {
566 	if (dso->last_find_result.addr != addr || dso->last_find_result.symbol == NULL) {
567 		dso->last_find_result.addr   = addr;
568 		dso->last_find_result.symbol = symbols__find(&dso->symbols, addr);
569 	}
570 
571 	return dso->last_find_result.symbol;
572 }
573 
574 struct symbol *dso__find_symbol_nocache(struct dso *dso, u64 addr)
575 {
576 	return symbols__find(&dso->symbols, addr);
577 }
578 
579 struct symbol *dso__first_symbol(struct dso *dso)
580 {
581 	return symbols__first(&dso->symbols);
582 }
583 
584 struct symbol *dso__last_symbol(struct dso *dso)
585 {
586 	return symbols__last(&dso->symbols);
587 }
588 
589 struct symbol *dso__next_symbol(struct symbol *sym)
590 {
591 	return symbols__next(sym);
592 }
593 
594 struct symbol *dso__next_symbol_by_name(struct dso *dso, size_t *idx)
595 {
596 	if (*idx + 1 >= dso->symbol_names_len)
597 		return NULL;
598 
599 	++*idx;
600 	return dso->symbol_names[*idx];
601 }
602 
603  /*
604   * Returns first symbol that matched with @name.
605   */
606 struct symbol *dso__find_symbol_by_name(struct dso *dso, const char *name, size_t *idx)
607 {
608 	struct symbol *s = symbols__find_by_name(dso->symbol_names, dso->symbol_names_len,
609 						name, SYMBOL_TAG_INCLUDE__NONE, idx);
610 	if (!s)
611 		s = symbols__find_by_name(dso->symbol_names, dso->symbol_names_len,
612 					name, SYMBOL_TAG_INCLUDE__DEFAULT_ONLY, idx);
613 	return s;
614 }
615 
616 void dso__sort_by_name(struct dso *dso)
617 {
618 	mutex_lock(&dso->lock);
619 	if (!dso__sorted_by_name(dso)) {
620 		size_t len;
621 
622 		dso->symbol_names = symbols__sort_by_name(&dso->symbols, &len);
623 		if (dso->symbol_names) {
624 			dso->symbol_names_len = len;
625 			dso__set_sorted_by_name(dso);
626 		}
627 	}
628 	mutex_unlock(&dso->lock);
629 }
630 
631 /*
632  * While we find nice hex chars, build a long_val.
633  * Return number of chars processed.
634  */
635 static int hex2u64(const char *ptr, u64 *long_val)
636 {
637 	char *p;
638 
639 	*long_val = strtoull(ptr, &p, 16);
640 
641 	return p - ptr;
642 }
643 
644 
645 int modules__parse(const char *filename, void *arg,
646 		   int (*process_module)(void *arg, const char *name,
647 					 u64 start, u64 size))
648 {
649 	char *line = NULL;
650 	size_t n;
651 	FILE *file;
652 	int err = 0;
653 
654 	file = fopen(filename, "r");
655 	if (file == NULL)
656 		return -1;
657 
658 	while (1) {
659 		char name[PATH_MAX];
660 		u64 start, size;
661 		char *sep, *endptr;
662 		ssize_t line_len;
663 
664 		line_len = getline(&line, &n, file);
665 		if (line_len < 0) {
666 			if (feof(file))
667 				break;
668 			err = -1;
669 			goto out;
670 		}
671 
672 		if (!line) {
673 			err = -1;
674 			goto out;
675 		}
676 
677 		line[--line_len] = '\0'; /* \n */
678 
679 		sep = strrchr(line, 'x');
680 		if (sep == NULL)
681 			continue;
682 
683 		hex2u64(sep + 1, &start);
684 
685 		sep = strchr(line, ' ');
686 		if (sep == NULL)
687 			continue;
688 
689 		*sep = '\0';
690 
691 		scnprintf(name, sizeof(name), "[%s]", line);
692 
693 		size = strtoul(sep + 1, &endptr, 0);
694 		if (*endptr != ' ' && *endptr != '\t')
695 			continue;
696 
697 		err = process_module(arg, name, start, size);
698 		if (err)
699 			break;
700 	}
701 out:
702 	free(line);
703 	fclose(file);
704 	return err;
705 }
706 
707 /*
708  * These are symbols in the kernel image, so make sure that
709  * sym is from a kernel DSO.
710  */
711 static bool symbol__is_idle(const char *name)
712 {
713 	const char * const idle_symbols[] = {
714 		"acpi_idle_do_entry",
715 		"acpi_processor_ffh_cstate_enter",
716 		"arch_cpu_idle",
717 		"cpu_idle",
718 		"cpu_startup_entry",
719 		"idle_cpu",
720 		"intel_idle",
721 		"default_idle",
722 		"native_safe_halt",
723 		"enter_idle",
724 		"exit_idle",
725 		"mwait_idle",
726 		"mwait_idle_with_hints",
727 		"mwait_idle_with_hints.constprop.0",
728 		"poll_idle",
729 		"ppc64_runlatch_off",
730 		"pseries_dedicated_idle_sleep",
731 		"psw_idle",
732 		"psw_idle_exit",
733 		NULL
734 	};
735 	int i;
736 	static struct strlist *idle_symbols_list;
737 
738 	if (idle_symbols_list)
739 		return strlist__has_entry(idle_symbols_list, name);
740 
741 	idle_symbols_list = strlist__new(NULL, NULL);
742 
743 	for (i = 0; idle_symbols[i]; i++)
744 		strlist__add(idle_symbols_list, idle_symbols[i]);
745 
746 	return strlist__has_entry(idle_symbols_list, name);
747 }
748 
749 static int map__process_kallsym_symbol(void *arg, const char *name,
750 				       char type, u64 start)
751 {
752 	struct symbol *sym;
753 	struct dso *dso = arg;
754 	struct rb_root_cached *root = &dso->symbols;
755 
756 	if (!symbol_type__filter(type))
757 		return 0;
758 
759 	/* Ignore local symbols for ARM modules */
760 	if (name[0] == '$')
761 		return 0;
762 
763 	/*
764 	 * module symbols are not sorted so we add all
765 	 * symbols, setting length to 0, and rely on
766 	 * symbols__fixup_end() to fix it up.
767 	 */
768 	sym = symbol__new(start, 0, kallsyms2elf_binding(type), kallsyms2elf_type(type), name);
769 	if (sym == NULL)
770 		return -ENOMEM;
771 	/*
772 	 * We will pass the symbols to the filter later, in
773 	 * map__split_kallsyms, when we have split the maps per module
774 	 */
775 	__symbols__insert(root, sym, !strchr(name, '['));
776 
777 	return 0;
778 }
779 
780 /*
781  * Loads the function entries in /proc/kallsyms into kernel_map->dso,
782  * so that we can in the next step set the symbol ->end address and then
783  * call kernel_maps__split_kallsyms.
784  */
785 static int dso__load_all_kallsyms(struct dso *dso, const char *filename)
786 {
787 	return kallsyms__parse(filename, dso, map__process_kallsym_symbol);
788 }
789 
790 static int maps__split_kallsyms_for_kcore(struct maps *kmaps, struct dso *dso)
791 {
792 	struct map *curr_map;
793 	struct symbol *pos;
794 	int count = 0;
795 	struct rb_root_cached old_root = dso->symbols;
796 	struct rb_root_cached *root = &dso->symbols;
797 	struct rb_node *next = rb_first_cached(root);
798 
799 	if (!kmaps)
800 		return -1;
801 
802 	*root = RB_ROOT_CACHED;
803 
804 	while (next) {
805 		struct dso *curr_map_dso;
806 		char *module;
807 
808 		pos = rb_entry(next, struct symbol, rb_node);
809 		next = rb_next(&pos->rb_node);
810 
811 		rb_erase_cached(&pos->rb_node, &old_root);
812 		RB_CLEAR_NODE(&pos->rb_node);
813 		module = strchr(pos->name, '\t');
814 		if (module)
815 			*module = '\0';
816 
817 		curr_map = maps__find(kmaps, pos->start);
818 
819 		if (!curr_map) {
820 			symbol__delete(pos);
821 			continue;
822 		}
823 		curr_map_dso = map__dso(curr_map);
824 		pos->start -= map__start(curr_map) - map__pgoff(curr_map);
825 		if (pos->end > map__end(curr_map))
826 			pos->end = map__end(curr_map);
827 		if (pos->end)
828 			pos->end -= map__start(curr_map) - map__pgoff(curr_map);
829 		symbols__insert(&curr_map_dso->symbols, pos);
830 		++count;
831 	}
832 
833 	/* Symbols have been adjusted */
834 	dso->adjust_symbols = 1;
835 
836 	return count;
837 }
838 
839 /*
840  * Split the symbols into maps, making sure there are no overlaps, i.e. the
841  * kernel range is broken in several maps, named [kernel].N, as we don't have
842  * the original ELF section names vmlinux have.
843  */
844 static int maps__split_kallsyms(struct maps *kmaps, struct dso *dso, u64 delta,
845 				struct map *initial_map)
846 {
847 	struct machine *machine;
848 	struct map *curr_map = initial_map;
849 	struct symbol *pos;
850 	int count = 0, moved = 0;
851 	struct rb_root_cached *root = &dso->symbols;
852 	struct rb_node *next = rb_first_cached(root);
853 	int kernel_range = 0;
854 	bool x86_64;
855 
856 	if (!kmaps)
857 		return -1;
858 
859 	machine = maps__machine(kmaps);
860 
861 	x86_64 = machine__is(machine, "x86_64");
862 
863 	while (next) {
864 		char *module;
865 
866 		pos = rb_entry(next, struct symbol, rb_node);
867 		next = rb_next(&pos->rb_node);
868 
869 		module = strchr(pos->name, '\t');
870 		if (module) {
871 			struct dso *curr_map_dso;
872 
873 			if (!symbol_conf.use_modules)
874 				goto discard_symbol;
875 
876 			*module++ = '\0';
877 			curr_map_dso = map__dso(curr_map);
878 			if (strcmp(curr_map_dso->short_name, module)) {
879 				if (RC_CHK_ACCESS(curr_map) != RC_CHK_ACCESS(initial_map) &&
880 				    dso->kernel == DSO_SPACE__KERNEL_GUEST &&
881 				    machine__is_default_guest(machine)) {
882 					/*
883 					 * We assume all symbols of a module are
884 					 * continuous in * kallsyms, so curr_map
885 					 * points to a module and all its
886 					 * symbols are in its kmap. Mark it as
887 					 * loaded.
888 					 */
889 					dso__set_loaded(curr_map_dso);
890 				}
891 
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 = initial_map;
899 					goto discard_symbol;
900 				}
901 				curr_map_dso = map__dso(curr_map);
902 				if (curr_map_dso->loaded &&
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 (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 				curr_map = initial_map;
934 				goto add_symbol;
935 			}
936 
937 			if (dso->kernel == DSO_SPACE__KERNEL_GUEST)
938 				snprintf(dso_name, sizeof(dso_name),
939 					"[guest.kernel].%d",
940 					kernel_range++);
941 			else
942 				snprintf(dso_name, sizeof(dso_name),
943 					"[kernel].%d",
944 					kernel_range++);
945 
946 			ndso = dso__new(dso_name);
947 			if (ndso == NULL)
948 				return -1;
949 
950 			ndso->kernel = dso->kernel;
951 
952 			curr_map = map__new2(pos->start, ndso);
953 			if (curr_map == NULL) {
954 				dso__put(ndso);
955 				return -1;
956 			}
957 
958 			map__set_map_ip(curr_map, identity__map_ip);
959 			map__set_unmap_ip(curr_map, identity__map_ip);
960 			if (maps__insert(kmaps, curr_map)) {
961 				dso__put(ndso);
962 				return -1;
963 			}
964 			++kernel_range;
965 		} else if (delta) {
966 			/* Kernel was relocated at boot time */
967 			pos->start -= delta;
968 			pos->end -= delta;
969 		}
970 add_symbol:
971 		if (curr_map != initial_map) {
972 			struct dso *curr_map_dso = map__dso(curr_map);
973 
974 			rb_erase_cached(&pos->rb_node, root);
975 			symbols__insert(&curr_map_dso->symbols, pos);
976 			++moved;
977 		} else
978 			++count;
979 
980 		continue;
981 discard_symbol:
982 		rb_erase_cached(&pos->rb_node, root);
983 		symbol__delete(pos);
984 	}
985 
986 	if (curr_map != initial_map &&
987 	    dso->kernel == DSO_SPACE__KERNEL_GUEST &&
988 	    machine__is_default_guest(maps__machine(kmaps))) {
989 		dso__set_loaded(map__dso(curr_map));
990 	}
991 
992 	return count + moved;
993 }
994 
995 bool symbol__restricted_filename(const char *filename,
996 				 const char *restricted_filename)
997 {
998 	bool restricted = false;
999 
1000 	if (symbol_conf.kptr_restrict) {
1001 		char *r = realpath(filename, NULL);
1002 
1003 		if (r != NULL) {
1004 			restricted = strcmp(r, restricted_filename) == 0;
1005 			free(r);
1006 			return restricted;
1007 		}
1008 	}
1009 
1010 	return restricted;
1011 }
1012 
1013 struct module_info {
1014 	struct rb_node rb_node;
1015 	char *name;
1016 	u64 start;
1017 };
1018 
1019 static void add_module(struct module_info *mi, struct rb_root *modules)
1020 {
1021 	struct rb_node **p = &modules->rb_node;
1022 	struct rb_node *parent = NULL;
1023 	struct module_info *m;
1024 
1025 	while (*p != NULL) {
1026 		parent = *p;
1027 		m = rb_entry(parent, struct module_info, rb_node);
1028 		if (strcmp(mi->name, m->name) < 0)
1029 			p = &(*p)->rb_left;
1030 		else
1031 			p = &(*p)->rb_right;
1032 	}
1033 	rb_link_node(&mi->rb_node, parent, p);
1034 	rb_insert_color(&mi->rb_node, modules);
1035 }
1036 
1037 static void delete_modules(struct rb_root *modules)
1038 {
1039 	struct module_info *mi;
1040 	struct rb_node *next = rb_first(modules);
1041 
1042 	while (next) {
1043 		mi = rb_entry(next, struct module_info, rb_node);
1044 		next = rb_next(&mi->rb_node);
1045 		rb_erase(&mi->rb_node, modules);
1046 		zfree(&mi->name);
1047 		free(mi);
1048 	}
1049 }
1050 
1051 static struct module_info *find_module(const char *name,
1052 				       struct rb_root *modules)
1053 {
1054 	struct rb_node *n = modules->rb_node;
1055 
1056 	while (n) {
1057 		struct module_info *m;
1058 		int cmp;
1059 
1060 		m = rb_entry(n, struct module_info, rb_node);
1061 		cmp = strcmp(name, m->name);
1062 		if (cmp < 0)
1063 			n = n->rb_left;
1064 		else if (cmp > 0)
1065 			n = n->rb_right;
1066 		else
1067 			return m;
1068 	}
1069 
1070 	return NULL;
1071 }
1072 
1073 static int __read_proc_modules(void *arg, const char *name, u64 start,
1074 			       u64 size __maybe_unused)
1075 {
1076 	struct rb_root *modules = arg;
1077 	struct module_info *mi;
1078 
1079 	mi = zalloc(sizeof(struct module_info));
1080 	if (!mi)
1081 		return -ENOMEM;
1082 
1083 	mi->name = strdup(name);
1084 	mi->start = start;
1085 
1086 	if (!mi->name) {
1087 		free(mi);
1088 		return -ENOMEM;
1089 	}
1090 
1091 	add_module(mi, modules);
1092 
1093 	return 0;
1094 }
1095 
1096 static int read_proc_modules(const char *filename, struct rb_root *modules)
1097 {
1098 	if (symbol__restricted_filename(filename, "/proc/modules"))
1099 		return -1;
1100 
1101 	if (modules__parse(filename, modules, __read_proc_modules)) {
1102 		delete_modules(modules);
1103 		return -1;
1104 	}
1105 
1106 	return 0;
1107 }
1108 
1109 int compare_proc_modules(const char *from, const char *to)
1110 {
1111 	struct rb_root from_modules = RB_ROOT;
1112 	struct rb_root to_modules = RB_ROOT;
1113 	struct rb_node *from_node, *to_node;
1114 	struct module_info *from_m, *to_m;
1115 	int ret = -1;
1116 
1117 	if (read_proc_modules(from, &from_modules))
1118 		return -1;
1119 
1120 	if (read_proc_modules(to, &to_modules))
1121 		goto out_delete_from;
1122 
1123 	from_node = rb_first(&from_modules);
1124 	to_node = rb_first(&to_modules);
1125 	while (from_node) {
1126 		if (!to_node)
1127 			break;
1128 
1129 		from_m = rb_entry(from_node, struct module_info, rb_node);
1130 		to_m = rb_entry(to_node, struct module_info, rb_node);
1131 
1132 		if (from_m->start != to_m->start ||
1133 		    strcmp(from_m->name, to_m->name))
1134 			break;
1135 
1136 		from_node = rb_next(from_node);
1137 		to_node = rb_next(to_node);
1138 	}
1139 
1140 	if (!from_node && !to_node)
1141 		ret = 0;
1142 
1143 	delete_modules(&to_modules);
1144 out_delete_from:
1145 	delete_modules(&from_modules);
1146 
1147 	return ret;
1148 }
1149 
1150 static int do_validate_kcore_modules(const char *filename, struct maps *kmaps)
1151 {
1152 	struct rb_root modules = RB_ROOT;
1153 	struct map_rb_node *old_node;
1154 	int err;
1155 
1156 	err = read_proc_modules(filename, &modules);
1157 	if (err)
1158 		return err;
1159 
1160 	maps__for_each_entry(kmaps, old_node) {
1161 		struct map *old_map = old_node->map;
1162 		struct module_info *mi;
1163 		struct dso *dso;
1164 
1165 		if (!__map__is_kmodule(old_map)) {
1166 			continue;
1167 		}
1168 		dso = map__dso(old_map);
1169 		/* Module must be in memory at the same address */
1170 		mi = find_module(dso->short_name, &modules);
1171 		if (!mi || mi->start != map__start(old_map)) {
1172 			err = -EINVAL;
1173 			goto out;
1174 		}
1175 	}
1176 out:
1177 	delete_modules(&modules);
1178 	return err;
1179 }
1180 
1181 /*
1182  * If kallsyms is referenced by name then we look for filename in the same
1183  * directory.
1184  */
1185 static bool filename_from_kallsyms_filename(char *filename,
1186 					    const char *base_name,
1187 					    const char *kallsyms_filename)
1188 {
1189 	char *name;
1190 
1191 	strcpy(filename, kallsyms_filename);
1192 	name = strrchr(filename, '/');
1193 	if (!name)
1194 		return false;
1195 
1196 	name += 1;
1197 
1198 	if (!strcmp(name, "kallsyms")) {
1199 		strcpy(name, base_name);
1200 		return true;
1201 	}
1202 
1203 	return false;
1204 }
1205 
1206 static int validate_kcore_modules(const char *kallsyms_filename,
1207 				  struct map *map)
1208 {
1209 	struct maps *kmaps = map__kmaps(map);
1210 	char modules_filename[PATH_MAX];
1211 
1212 	if (!kmaps)
1213 		return -EINVAL;
1214 
1215 	if (!filename_from_kallsyms_filename(modules_filename, "modules",
1216 					     kallsyms_filename))
1217 		return -EINVAL;
1218 
1219 	if (do_validate_kcore_modules(modules_filename, kmaps))
1220 		return -EINVAL;
1221 
1222 	return 0;
1223 }
1224 
1225 static int validate_kcore_addresses(const char *kallsyms_filename,
1226 				    struct map *map)
1227 {
1228 	struct kmap *kmap = map__kmap(map);
1229 
1230 	if (!kmap)
1231 		return -EINVAL;
1232 
1233 	if (kmap->ref_reloc_sym && kmap->ref_reloc_sym->name) {
1234 		u64 start;
1235 
1236 		if (kallsyms__get_function_start(kallsyms_filename,
1237 						 kmap->ref_reloc_sym->name, &start))
1238 			return -ENOENT;
1239 		if (start != kmap->ref_reloc_sym->addr)
1240 			return -EINVAL;
1241 	}
1242 
1243 	return validate_kcore_modules(kallsyms_filename, map);
1244 }
1245 
1246 struct kcore_mapfn_data {
1247 	struct dso *dso;
1248 	struct list_head maps;
1249 };
1250 
1251 static int kcore_mapfn(u64 start, u64 len, u64 pgoff, void *data)
1252 {
1253 	struct kcore_mapfn_data *md = data;
1254 	struct map_list_node *list_node = map_list_node__new();
1255 
1256 	if (!list_node)
1257 		return -ENOMEM;
1258 
1259 	list_node->map = map__new2(start, md->dso);
1260 	if (!list_node->map) {
1261 		free(list_node);
1262 		return -ENOMEM;
1263 	}
1264 
1265 	map__set_end(list_node->map, map__start(list_node->map) + len);
1266 	map__set_pgoff(list_node->map, pgoff);
1267 
1268 	list_add(&list_node->node, &md->maps);
1269 
1270 	return 0;
1271 }
1272 
1273 /*
1274  * Merges map into maps by splitting the new map within the existing map
1275  * regions.
1276  */
1277 int maps__merge_in(struct maps *kmaps, struct map *new_map)
1278 {
1279 	struct map_rb_node *rb_node;
1280 	LIST_HEAD(merged);
1281 	int err = 0;
1282 
1283 	maps__for_each_entry(kmaps, rb_node) {
1284 		struct map *old_map = rb_node->map;
1285 
1286 		/* no overload with this one */
1287 		if (map__end(new_map) < map__start(old_map) ||
1288 		    map__start(new_map) >= map__end(old_map))
1289 			continue;
1290 
1291 		if (map__start(new_map) < map__start(old_map)) {
1292 			/*
1293 			 * |new......
1294 			 *       |old....
1295 			 */
1296 			if (map__end(new_map) < map__end(old_map)) {
1297 				/*
1298 				 * |new......|     -> |new..|
1299 				 *       |old....| ->       |old....|
1300 				 */
1301 				map__set_end(new_map, map__start(old_map));
1302 			} else {
1303 				/*
1304 				 * |new.............| -> |new..|       |new..|
1305 				 *       |old....|    ->       |old....|
1306 				 */
1307 				struct map_list_node *m = map_list_node__new();
1308 
1309 				if (!m) {
1310 					err = -ENOMEM;
1311 					goto out;
1312 				}
1313 
1314 				m->map = map__clone(new_map);
1315 				if (!m->map) {
1316 					free(m);
1317 					err = -ENOMEM;
1318 					goto out;
1319 				}
1320 
1321 				map__set_end(m->map, map__start(old_map));
1322 				list_add_tail(&m->node, &merged);
1323 				map__add_pgoff(new_map, map__end(old_map) - map__start(new_map));
1324 				map__set_start(new_map, map__end(old_map));
1325 			}
1326 		} else {
1327 			/*
1328 			 *      |new......
1329 			 * |old....
1330 			 */
1331 			if (map__end(new_map) < map__end(old_map)) {
1332 				/*
1333 				 *      |new..|   -> x
1334 				 * |old.........| -> |old.........|
1335 				 */
1336 				map__put(new_map);
1337 				new_map = NULL;
1338 				break;
1339 			} else {
1340 				/*
1341 				 *      |new......| ->         |new...|
1342 				 * |old....|        -> |old....|
1343 				 */
1344 				map__add_pgoff(new_map, map__end(old_map) - map__start(new_map));
1345 				map__set_start(new_map, map__end(old_map));
1346 			}
1347 		}
1348 	}
1349 
1350 out:
1351 	while (!list_empty(&merged)) {
1352 		struct map_list_node *old_node;
1353 
1354 		old_node = list_entry(merged.next, struct map_list_node, node);
1355 		list_del_init(&old_node->node);
1356 		if (!err)
1357 			err = maps__insert(kmaps, old_node->map);
1358 		map__put(old_node->map);
1359 		free(old_node);
1360 	}
1361 
1362 	if (new_map) {
1363 		if (!err)
1364 			err = maps__insert(kmaps, new_map);
1365 		map__put(new_map);
1366 	}
1367 	return err;
1368 }
1369 
1370 static int dso__load_kcore(struct dso *dso, struct map *map,
1371 			   const char *kallsyms_filename)
1372 {
1373 	struct maps *kmaps = map__kmaps(map);
1374 	struct kcore_mapfn_data md;
1375 	struct map *replacement_map = NULL;
1376 	struct map_rb_node *old_node, *next;
1377 	struct machine *machine;
1378 	bool is_64_bit;
1379 	int err, fd;
1380 	char kcore_filename[PATH_MAX];
1381 	u64 stext;
1382 
1383 	if (!kmaps)
1384 		return -EINVAL;
1385 
1386 	machine = maps__machine(kmaps);
1387 
1388 	/* This function requires that the map is the kernel map */
1389 	if (!__map__is_kernel(map))
1390 		return -EINVAL;
1391 
1392 	if (!filename_from_kallsyms_filename(kcore_filename, "kcore",
1393 					     kallsyms_filename))
1394 		return -EINVAL;
1395 
1396 	/* Modules and kernel must be present at their original addresses */
1397 	if (validate_kcore_addresses(kallsyms_filename, map))
1398 		return -EINVAL;
1399 
1400 	md.dso = dso;
1401 	INIT_LIST_HEAD(&md.maps);
1402 
1403 	fd = open(kcore_filename, O_RDONLY);
1404 	if (fd < 0) {
1405 		pr_debug("Failed to open %s. Note /proc/kcore requires CAP_SYS_RAWIO capability to access.\n",
1406 			 kcore_filename);
1407 		return -EINVAL;
1408 	}
1409 
1410 	/* Read new maps into temporary lists */
1411 	err = file__read_maps(fd, map__prot(map) & PROT_EXEC, kcore_mapfn, &md,
1412 			      &is_64_bit);
1413 	if (err)
1414 		goto out_err;
1415 	dso->is_64_bit = is_64_bit;
1416 
1417 	if (list_empty(&md.maps)) {
1418 		err = -EINVAL;
1419 		goto out_err;
1420 	}
1421 
1422 	/* Remove old maps */
1423 	maps__for_each_entry_safe(kmaps, old_node, next) {
1424 		struct map *old_map = old_node->map;
1425 
1426 		/*
1427 		 * We need to preserve eBPF maps even if they are
1428 		 * covered by kcore, because we need to access
1429 		 * eBPF dso for source data.
1430 		 */
1431 		if (old_map != map && !__map__is_bpf_prog(old_map))
1432 			maps__remove(kmaps, old_map);
1433 	}
1434 	machine->trampolines_mapped = false;
1435 
1436 	/* Find the kernel map using the '_stext' symbol */
1437 	if (!kallsyms__get_function_start(kallsyms_filename, "_stext", &stext)) {
1438 		u64 replacement_size = 0;
1439 		struct map_list_node *new_node;
1440 
1441 		list_for_each_entry(new_node, &md.maps, node) {
1442 			struct map *new_map = new_node->map;
1443 			u64 new_size = map__size(new_map);
1444 
1445 			if (!(stext >= map__start(new_map) && stext < map__end(new_map)))
1446 				continue;
1447 
1448 			/*
1449 			 * On some architectures, ARM64 for example, the kernel
1450 			 * text can get allocated inside of the vmalloc segment.
1451 			 * Select the smallest matching segment, in case stext
1452 			 * falls within more than one in the list.
1453 			 */
1454 			if (!replacement_map || new_size < replacement_size) {
1455 				replacement_map = new_map;
1456 				replacement_size = new_size;
1457 			}
1458 		}
1459 	}
1460 
1461 	if (!replacement_map)
1462 		replacement_map = list_entry(md.maps.next, struct map_list_node, node)->map;
1463 
1464 	/* Add new maps */
1465 	while (!list_empty(&md.maps)) {
1466 		struct map_list_node *new_node = list_entry(md.maps.next, struct map_list_node, node);
1467 		struct map *new_map = new_node->map;
1468 
1469 		list_del_init(&new_node->node);
1470 
1471 		if (RC_CHK_ACCESS(new_map) == RC_CHK_ACCESS(replacement_map)) {
1472 			struct map *map_ref;
1473 
1474 			map__set_start(map, map__start(new_map));
1475 			map__set_end(map, map__end(new_map));
1476 			map__set_pgoff(map, map__pgoff(new_map));
1477 			map__set_map_ip(map, map__map_ip_ptr(new_map));
1478 			map__set_unmap_ip(map, map__unmap_ip_ptr(new_map));
1479 			/* Ensure maps are correctly ordered */
1480 			map_ref = map__get(map);
1481 			maps__remove(kmaps, map_ref);
1482 			err = maps__insert(kmaps, map_ref);
1483 			map__put(map_ref);
1484 			map__put(new_map);
1485 			if (err)
1486 				goto out_err;
1487 		} else {
1488 			/*
1489 			 * Merge kcore map into existing maps,
1490 			 * and ensure that current maps (eBPF)
1491 			 * stay intact.
1492 			 */
1493 			if (maps__merge_in(kmaps, new_map)) {
1494 				err = -EINVAL;
1495 				goto out_err;
1496 			}
1497 		}
1498 		free(new_node);
1499 	}
1500 
1501 	if (machine__is(machine, "x86_64")) {
1502 		u64 addr;
1503 
1504 		/*
1505 		 * If one of the corresponding symbols is there, assume the
1506 		 * entry trampoline maps are too.
1507 		 */
1508 		if (!kallsyms__get_function_start(kallsyms_filename,
1509 						  ENTRY_TRAMPOLINE_NAME,
1510 						  &addr))
1511 			machine->trampolines_mapped = true;
1512 	}
1513 
1514 	/*
1515 	 * Set the data type and long name so that kcore can be read via
1516 	 * dso__data_read_addr().
1517 	 */
1518 	if (dso->kernel == DSO_SPACE__KERNEL_GUEST)
1519 		dso->binary_type = DSO_BINARY_TYPE__GUEST_KCORE;
1520 	else
1521 		dso->binary_type = DSO_BINARY_TYPE__KCORE;
1522 	dso__set_long_name(dso, strdup(kcore_filename), true);
1523 
1524 	close(fd);
1525 
1526 	if (map__prot(map) & PROT_EXEC)
1527 		pr_debug("Using %s for kernel object code\n", kcore_filename);
1528 	else
1529 		pr_debug("Using %s for kernel data\n", kcore_filename);
1530 
1531 	return 0;
1532 
1533 out_err:
1534 	while (!list_empty(&md.maps)) {
1535 		struct map_list_node *list_node;
1536 
1537 		list_node = list_entry(md.maps.next, struct map_list_node, node);
1538 		list_del_init(&list_node->node);
1539 		map__zput(list_node->map);
1540 		free(list_node);
1541 	}
1542 	close(fd);
1543 	return err;
1544 }
1545 
1546 /*
1547  * If the kernel is relocated at boot time, kallsyms won't match.  Compute the
1548  * delta based on the relocation reference symbol.
1549  */
1550 static int kallsyms__delta(struct kmap *kmap, const char *filename, u64 *delta)
1551 {
1552 	u64 addr;
1553 
1554 	if (!kmap->ref_reloc_sym || !kmap->ref_reloc_sym->name)
1555 		return 0;
1556 
1557 	if (kallsyms__get_function_start(filename, kmap->ref_reloc_sym->name, &addr))
1558 		return -1;
1559 
1560 	*delta = addr - kmap->ref_reloc_sym->addr;
1561 	return 0;
1562 }
1563 
1564 int __dso__load_kallsyms(struct dso *dso, const char *filename,
1565 			 struct map *map, bool no_kcore)
1566 {
1567 	struct kmap *kmap = map__kmap(map);
1568 	u64 delta = 0;
1569 
1570 	if (symbol__restricted_filename(filename, "/proc/kallsyms"))
1571 		return -1;
1572 
1573 	if (!kmap || !kmap->kmaps)
1574 		return -1;
1575 
1576 	if (dso__load_all_kallsyms(dso, filename) < 0)
1577 		return -1;
1578 
1579 	if (kallsyms__delta(kmap, filename, &delta))
1580 		return -1;
1581 
1582 	symbols__fixup_end(&dso->symbols, true);
1583 	symbols__fixup_duplicate(&dso->symbols);
1584 
1585 	if (dso->kernel == DSO_SPACE__KERNEL_GUEST)
1586 		dso->symtab_type = DSO_BINARY_TYPE__GUEST_KALLSYMS;
1587 	else
1588 		dso->symtab_type = DSO_BINARY_TYPE__KALLSYMS;
1589 
1590 	if (!no_kcore && !dso__load_kcore(dso, map, filename))
1591 		return maps__split_kallsyms_for_kcore(kmap->kmaps, dso);
1592 	else
1593 		return maps__split_kallsyms(kmap->kmaps, dso, delta, map);
1594 }
1595 
1596 int dso__load_kallsyms(struct dso *dso, const char *filename,
1597 		       struct map *map)
1598 {
1599 	return __dso__load_kallsyms(dso, filename, map, false);
1600 }
1601 
1602 static int dso__load_perf_map(const char *map_path, struct dso *dso)
1603 {
1604 	char *line = NULL;
1605 	size_t n;
1606 	FILE *file;
1607 	int nr_syms = 0;
1608 
1609 	file = fopen(map_path, "r");
1610 	if (file == NULL)
1611 		goto out_failure;
1612 
1613 	while (!feof(file)) {
1614 		u64 start, size;
1615 		struct symbol *sym;
1616 		int line_len, len;
1617 
1618 		line_len = getline(&line, &n, file);
1619 		if (line_len < 0)
1620 			break;
1621 
1622 		if (!line)
1623 			goto out_failure;
1624 
1625 		line[--line_len] = '\0'; /* \n */
1626 
1627 		len = hex2u64(line, &start);
1628 
1629 		len++;
1630 		if (len + 2 >= line_len)
1631 			continue;
1632 
1633 		len += hex2u64(line + len, &size);
1634 
1635 		len++;
1636 		if (len + 2 >= line_len)
1637 			continue;
1638 
1639 		sym = symbol__new(start, size, STB_GLOBAL, STT_FUNC, line + len);
1640 
1641 		if (sym == NULL)
1642 			goto out_delete_line;
1643 
1644 		symbols__insert(&dso->symbols, sym);
1645 		nr_syms++;
1646 	}
1647 
1648 	free(line);
1649 	fclose(file);
1650 
1651 	return nr_syms;
1652 
1653 out_delete_line:
1654 	free(line);
1655 out_failure:
1656 	return -1;
1657 }
1658 
1659 #ifdef HAVE_LIBBFD_SUPPORT
1660 #define PACKAGE 'perf'
1661 #include <bfd.h>
1662 
1663 static int bfd_symbols__cmpvalue(const void *a, const void *b)
1664 {
1665 	const asymbol *as = *(const asymbol **)a, *bs = *(const asymbol **)b;
1666 
1667 	if (bfd_asymbol_value(as) != bfd_asymbol_value(bs))
1668 		return bfd_asymbol_value(as) - bfd_asymbol_value(bs);
1669 
1670 	return bfd_asymbol_name(as)[0] - bfd_asymbol_name(bs)[0];
1671 }
1672 
1673 static int bfd2elf_binding(asymbol *symbol)
1674 {
1675 	if (symbol->flags & BSF_WEAK)
1676 		return STB_WEAK;
1677 	if (symbol->flags & BSF_GLOBAL)
1678 		return STB_GLOBAL;
1679 	if (symbol->flags & BSF_LOCAL)
1680 		return STB_LOCAL;
1681 	return -1;
1682 }
1683 
1684 int dso__load_bfd_symbols(struct dso *dso, const char *debugfile)
1685 {
1686 	int err = -1;
1687 	long symbols_size, symbols_count, i;
1688 	asection *section;
1689 	asymbol **symbols, *sym;
1690 	struct symbol *symbol;
1691 	bfd *abfd;
1692 	u64 start, len;
1693 
1694 	abfd = bfd_openr(debugfile, NULL);
1695 	if (!abfd)
1696 		return -1;
1697 
1698 	if (!bfd_check_format(abfd, bfd_object)) {
1699 		pr_debug2("%s: cannot read %s bfd file.\n", __func__,
1700 			  dso->long_name);
1701 		goto out_close;
1702 	}
1703 
1704 	if (bfd_get_flavour(abfd) == bfd_target_elf_flavour)
1705 		goto out_close;
1706 
1707 	symbols_size = bfd_get_symtab_upper_bound(abfd);
1708 	if (symbols_size == 0) {
1709 		bfd_close(abfd);
1710 		return 0;
1711 	}
1712 
1713 	if (symbols_size < 0)
1714 		goto out_close;
1715 
1716 	symbols = malloc(symbols_size);
1717 	if (!symbols)
1718 		goto out_close;
1719 
1720 	symbols_count = bfd_canonicalize_symtab(abfd, symbols);
1721 	if (symbols_count < 0)
1722 		goto out_free;
1723 
1724 	section = bfd_get_section_by_name(abfd, ".text");
1725 	if (section) {
1726 		for (i = 0; i < symbols_count; ++i) {
1727 			if (!strcmp(bfd_asymbol_name(symbols[i]), "__ImageBase") ||
1728 			    !strcmp(bfd_asymbol_name(symbols[i]), "__image_base__"))
1729 				break;
1730 		}
1731 		if (i < symbols_count) {
1732 			/* PE symbols can only have 4 bytes, so use .text high bits */
1733 			dso->text_offset = section->vma - (u32)section->vma;
1734 			dso->text_offset += (u32)bfd_asymbol_value(symbols[i]);
1735 		} else {
1736 			dso->text_offset = section->vma - section->filepos;
1737 		}
1738 	}
1739 
1740 	qsort(symbols, symbols_count, sizeof(asymbol *), bfd_symbols__cmpvalue);
1741 
1742 #ifdef bfd_get_section
1743 #define bfd_asymbol_section bfd_get_section
1744 #endif
1745 	for (i = 0; i < symbols_count; ++i) {
1746 		sym = symbols[i];
1747 		section = bfd_asymbol_section(sym);
1748 		if (bfd2elf_binding(sym) < 0)
1749 			continue;
1750 
1751 		while (i + 1 < symbols_count &&
1752 		       bfd_asymbol_section(symbols[i + 1]) == section &&
1753 		       bfd2elf_binding(symbols[i + 1]) < 0)
1754 			i++;
1755 
1756 		if (i + 1 < symbols_count &&
1757 		    bfd_asymbol_section(symbols[i + 1]) == section)
1758 			len = symbols[i + 1]->value - sym->value;
1759 		else
1760 			len = section->size - sym->value;
1761 
1762 		start = bfd_asymbol_value(sym) - dso->text_offset;
1763 		symbol = symbol__new(start, len, bfd2elf_binding(sym), STT_FUNC,
1764 				     bfd_asymbol_name(sym));
1765 		if (!symbol)
1766 			goto out_free;
1767 
1768 		symbols__insert(&dso->symbols, symbol);
1769 	}
1770 #ifdef bfd_get_section
1771 #undef bfd_asymbol_section
1772 #endif
1773 
1774 	symbols__fixup_end(&dso->symbols, false);
1775 	symbols__fixup_duplicate(&dso->symbols);
1776 	dso->adjust_symbols = 1;
1777 
1778 	err = 0;
1779 out_free:
1780 	free(symbols);
1781 out_close:
1782 	bfd_close(abfd);
1783 	return err;
1784 }
1785 #endif
1786 
1787 static bool dso__is_compatible_symtab_type(struct dso *dso, bool kmod,
1788 					   enum dso_binary_type type)
1789 {
1790 	switch (type) {
1791 	case DSO_BINARY_TYPE__JAVA_JIT:
1792 	case DSO_BINARY_TYPE__DEBUGLINK:
1793 	case DSO_BINARY_TYPE__SYSTEM_PATH_DSO:
1794 	case DSO_BINARY_TYPE__FEDORA_DEBUGINFO:
1795 	case DSO_BINARY_TYPE__UBUNTU_DEBUGINFO:
1796 	case DSO_BINARY_TYPE__MIXEDUP_UBUNTU_DEBUGINFO:
1797 	case DSO_BINARY_TYPE__BUILDID_DEBUGINFO:
1798 	case DSO_BINARY_TYPE__OPENEMBEDDED_DEBUGINFO:
1799 		return !kmod && dso->kernel == DSO_SPACE__USER;
1800 
1801 	case DSO_BINARY_TYPE__KALLSYMS:
1802 	case DSO_BINARY_TYPE__VMLINUX:
1803 	case DSO_BINARY_TYPE__KCORE:
1804 		return dso->kernel == DSO_SPACE__KERNEL;
1805 
1806 	case DSO_BINARY_TYPE__GUEST_KALLSYMS:
1807 	case DSO_BINARY_TYPE__GUEST_VMLINUX:
1808 	case DSO_BINARY_TYPE__GUEST_KCORE:
1809 		return dso->kernel == DSO_SPACE__KERNEL_GUEST;
1810 
1811 	case DSO_BINARY_TYPE__GUEST_KMODULE:
1812 	case DSO_BINARY_TYPE__GUEST_KMODULE_COMP:
1813 	case DSO_BINARY_TYPE__SYSTEM_PATH_KMODULE:
1814 	case DSO_BINARY_TYPE__SYSTEM_PATH_KMODULE_COMP:
1815 		/*
1816 		 * kernel modules know their symtab type - it's set when
1817 		 * creating a module dso in machine__addnew_module_map().
1818 		 */
1819 		return kmod && dso->symtab_type == type;
1820 
1821 	case DSO_BINARY_TYPE__BUILD_ID_CACHE:
1822 	case DSO_BINARY_TYPE__BUILD_ID_CACHE_DEBUGINFO:
1823 		return true;
1824 
1825 	case DSO_BINARY_TYPE__BPF_PROG_INFO:
1826 	case DSO_BINARY_TYPE__BPF_IMAGE:
1827 	case DSO_BINARY_TYPE__OOL:
1828 	case DSO_BINARY_TYPE__NOT_FOUND:
1829 	default:
1830 		return false;
1831 	}
1832 }
1833 
1834 /* Checks for the existence of the perf-<pid>.map file in two different
1835  * locations.  First, if the process is a separate mount namespace, check in
1836  * that namespace using the pid of the innermost pid namespace.  If's not in a
1837  * namespace, or the file can't be found there, try in the mount namespace of
1838  * the tracing process using our view of its pid.
1839  */
1840 static int dso__find_perf_map(char *filebuf, size_t bufsz,
1841 			      struct nsinfo **nsip)
1842 {
1843 	struct nscookie nsc;
1844 	struct nsinfo *nsi;
1845 	struct nsinfo *nnsi;
1846 	int rc = -1;
1847 
1848 	nsi = *nsip;
1849 
1850 	if (nsinfo__need_setns(nsi)) {
1851 		snprintf(filebuf, bufsz, "/tmp/perf-%d.map", nsinfo__nstgid(nsi));
1852 		nsinfo__mountns_enter(nsi, &nsc);
1853 		rc = access(filebuf, R_OK);
1854 		nsinfo__mountns_exit(&nsc);
1855 		if (rc == 0)
1856 			return rc;
1857 	}
1858 
1859 	nnsi = nsinfo__copy(nsi);
1860 	if (nnsi) {
1861 		nsinfo__put(nsi);
1862 
1863 		nsinfo__clear_need_setns(nnsi);
1864 		snprintf(filebuf, bufsz, "/tmp/perf-%d.map", nsinfo__tgid(nnsi));
1865 		*nsip = nnsi;
1866 		rc = 0;
1867 	}
1868 
1869 	return rc;
1870 }
1871 
1872 int dso__load(struct dso *dso, struct map *map)
1873 {
1874 	char *name;
1875 	int ret = -1;
1876 	u_int i;
1877 	struct machine *machine = NULL;
1878 	char *root_dir = (char *) "";
1879 	int ss_pos = 0;
1880 	struct symsrc ss_[2];
1881 	struct symsrc *syms_ss = NULL, *runtime_ss = NULL;
1882 	bool kmod;
1883 	bool perfmap;
1884 	struct build_id bid;
1885 	struct nscookie nsc;
1886 	char newmapname[PATH_MAX];
1887 	const char *map_path = dso->long_name;
1888 
1889 	mutex_lock(&dso->lock);
1890 	perfmap = strncmp(dso->name, "/tmp/perf-", 10) == 0;
1891 	if (perfmap) {
1892 		if (dso->nsinfo && (dso__find_perf_map(newmapname,
1893 		    sizeof(newmapname), &dso->nsinfo) == 0)) {
1894 			map_path = newmapname;
1895 		}
1896 	}
1897 
1898 	nsinfo__mountns_enter(dso->nsinfo, &nsc);
1899 
1900 	/* check again under the dso->lock */
1901 	if (dso__loaded(dso)) {
1902 		ret = 1;
1903 		goto out;
1904 	}
1905 
1906 	kmod = dso->symtab_type == DSO_BINARY_TYPE__SYSTEM_PATH_KMODULE ||
1907 		dso->symtab_type == DSO_BINARY_TYPE__SYSTEM_PATH_KMODULE_COMP ||
1908 		dso->symtab_type == DSO_BINARY_TYPE__GUEST_KMODULE ||
1909 		dso->symtab_type == DSO_BINARY_TYPE__GUEST_KMODULE_COMP;
1910 
1911 	if (dso->kernel && !kmod) {
1912 		if (dso->kernel == DSO_SPACE__KERNEL)
1913 			ret = dso__load_kernel_sym(dso, map);
1914 		else if (dso->kernel == DSO_SPACE__KERNEL_GUEST)
1915 			ret = dso__load_guest_kernel_sym(dso, map);
1916 
1917 		machine = maps__machine(map__kmaps(map));
1918 		if (machine__is(machine, "x86_64"))
1919 			machine__map_x86_64_entry_trampolines(machine, dso);
1920 		goto out;
1921 	}
1922 
1923 	dso->adjust_symbols = 0;
1924 
1925 	if (perfmap) {
1926 		ret = dso__load_perf_map(map_path, dso);
1927 		dso->symtab_type = ret > 0 ? DSO_BINARY_TYPE__JAVA_JIT :
1928 					     DSO_BINARY_TYPE__NOT_FOUND;
1929 		goto out;
1930 	}
1931 
1932 	if (machine)
1933 		root_dir = machine->root_dir;
1934 
1935 	name = malloc(PATH_MAX);
1936 	if (!name)
1937 		goto out;
1938 
1939 	/*
1940 	 * Read the build id if possible. This is required for
1941 	 * DSO_BINARY_TYPE__BUILDID_DEBUGINFO to work
1942 	 */
1943 	if (!dso->has_build_id &&
1944 	    is_regular_file(dso->long_name)) {
1945 	    __symbol__join_symfs(name, PATH_MAX, dso->long_name);
1946 		if (filename__read_build_id(name, &bid) > 0)
1947 			dso__set_build_id(dso, &bid);
1948 	}
1949 
1950 	/*
1951 	 * Iterate over candidate debug images.
1952 	 * Keep track of "interesting" ones (those which have a symtab, dynsym,
1953 	 * and/or opd section) for processing.
1954 	 */
1955 	for (i = 0; i < DSO_BINARY_TYPE__SYMTAB_CNT; i++) {
1956 		struct symsrc *ss = &ss_[ss_pos];
1957 		bool next_slot = false;
1958 		bool is_reg;
1959 		bool nsexit;
1960 		int bfdrc = -1;
1961 		int sirc = -1;
1962 
1963 		enum dso_binary_type symtab_type = binary_type_symtab[i];
1964 
1965 		nsexit = (symtab_type == DSO_BINARY_TYPE__BUILD_ID_CACHE ||
1966 		    symtab_type == DSO_BINARY_TYPE__BUILD_ID_CACHE_DEBUGINFO);
1967 
1968 		if (!dso__is_compatible_symtab_type(dso, kmod, symtab_type))
1969 			continue;
1970 
1971 		if (dso__read_binary_type_filename(dso, symtab_type,
1972 						   root_dir, name, PATH_MAX))
1973 			continue;
1974 
1975 		if (nsexit)
1976 			nsinfo__mountns_exit(&nsc);
1977 
1978 		is_reg = is_regular_file(name);
1979 		if (!is_reg && errno == ENOENT && dso->nsinfo) {
1980 			char *new_name = dso__filename_with_chroot(dso, name);
1981 			if (new_name) {
1982 				is_reg = is_regular_file(new_name);
1983 				strlcpy(name, new_name, PATH_MAX);
1984 				free(new_name);
1985 			}
1986 		}
1987 
1988 #ifdef HAVE_LIBBFD_SUPPORT
1989 		if (is_reg)
1990 			bfdrc = dso__load_bfd_symbols(dso, name);
1991 #endif
1992 		if (is_reg && bfdrc < 0)
1993 			sirc = symsrc__init(ss, dso, name, symtab_type);
1994 
1995 		if (nsexit)
1996 			nsinfo__mountns_enter(dso->nsinfo, &nsc);
1997 
1998 		if (bfdrc == 0) {
1999 			ret = 0;
2000 			break;
2001 		}
2002 
2003 		if (!is_reg || sirc < 0)
2004 			continue;
2005 
2006 		if (!syms_ss && symsrc__has_symtab(ss)) {
2007 			syms_ss = ss;
2008 			next_slot = true;
2009 			if (!dso->symsrc_filename)
2010 				dso->symsrc_filename = strdup(name);
2011 		}
2012 
2013 		if (!runtime_ss && symsrc__possibly_runtime(ss)) {
2014 			runtime_ss = ss;
2015 			next_slot = true;
2016 		}
2017 
2018 		if (next_slot) {
2019 			ss_pos++;
2020 
2021 			if (syms_ss && runtime_ss)
2022 				break;
2023 		} else {
2024 			symsrc__destroy(ss);
2025 		}
2026 
2027 	}
2028 
2029 	if (!runtime_ss && !syms_ss)
2030 		goto out_free;
2031 
2032 	if (runtime_ss && !syms_ss) {
2033 		syms_ss = runtime_ss;
2034 	}
2035 
2036 	/* We'll have to hope for the best */
2037 	if (!runtime_ss && syms_ss)
2038 		runtime_ss = syms_ss;
2039 
2040 	if (syms_ss)
2041 		ret = dso__load_sym(dso, map, syms_ss, runtime_ss, kmod);
2042 	else
2043 		ret = -1;
2044 
2045 	if (ret > 0) {
2046 		int nr_plt;
2047 
2048 		nr_plt = dso__synthesize_plt_symbols(dso, runtime_ss);
2049 		if (nr_plt > 0)
2050 			ret += nr_plt;
2051 	}
2052 
2053 	for (; ss_pos > 0; ss_pos--)
2054 		symsrc__destroy(&ss_[ss_pos - 1]);
2055 out_free:
2056 	free(name);
2057 	if (ret < 0 && strstr(dso->name, " (deleted)") != NULL)
2058 		ret = 0;
2059 out:
2060 	dso__set_loaded(dso);
2061 	mutex_unlock(&dso->lock);
2062 	nsinfo__mountns_exit(&nsc);
2063 
2064 	return ret;
2065 }
2066 
2067 static int map__strcmp(const void *a, const void *b)
2068 {
2069 	const struct map *map_a = *(const struct map **)a;
2070 	const struct map *map_b = *(const struct map **)b;
2071 	const struct dso *dso_a = map__dso(map_a);
2072 	const struct dso *dso_b = map__dso(map_b);
2073 	int ret = strcmp(dso_a->short_name, dso_b->short_name);
2074 
2075 	if (ret == 0 && map_a != map_b) {
2076 		/*
2077 		 * Ensure distinct but name equal maps have an order in part to
2078 		 * aid reference counting.
2079 		 */
2080 		ret = (int)map__start(map_a) - (int)map__start(map_b);
2081 		if (ret == 0)
2082 			ret = (int)((intptr_t)map_a - (intptr_t)map_b);
2083 	}
2084 
2085 	return ret;
2086 }
2087 
2088 static int map__strcmp_name(const void *name, const void *b)
2089 {
2090 	const struct dso *dso = map__dso(*(const struct map **)b);
2091 
2092 	return strcmp(name, dso->short_name);
2093 }
2094 
2095 void __maps__sort_by_name(struct maps *maps)
2096 {
2097 	qsort(maps__maps_by_name(maps), maps__nr_maps(maps), sizeof(struct map *), map__strcmp);
2098 }
2099 
2100 static int map__groups__sort_by_name_from_rbtree(struct maps *maps)
2101 {
2102 	struct map_rb_node *rb_node;
2103 	struct map **maps_by_name = realloc(maps__maps_by_name(maps),
2104 					    maps__nr_maps(maps) * sizeof(struct map *));
2105 	int i = 0;
2106 
2107 	if (maps_by_name == NULL)
2108 		return -1;
2109 
2110 	up_read(maps__lock(maps));
2111 	down_write(maps__lock(maps));
2112 
2113 	RC_CHK_ACCESS(maps)->maps_by_name = maps_by_name;
2114 	RC_CHK_ACCESS(maps)->nr_maps_allocated = maps__nr_maps(maps);
2115 
2116 	maps__for_each_entry(maps, rb_node)
2117 		maps_by_name[i++] = map__get(rb_node->map);
2118 
2119 	__maps__sort_by_name(maps);
2120 
2121 	up_write(maps__lock(maps));
2122 	down_read(maps__lock(maps));
2123 
2124 	return 0;
2125 }
2126 
2127 static struct map *__maps__find_by_name(struct maps *maps, const char *name)
2128 {
2129 	struct map **mapp;
2130 
2131 	if (maps__maps_by_name(maps) == NULL &&
2132 	    map__groups__sort_by_name_from_rbtree(maps))
2133 		return NULL;
2134 
2135 	mapp = bsearch(name, maps__maps_by_name(maps), maps__nr_maps(maps),
2136 		       sizeof(*mapp), map__strcmp_name);
2137 	if (mapp)
2138 		return *mapp;
2139 	return NULL;
2140 }
2141 
2142 struct map *maps__find_by_name(struct maps *maps, const char *name)
2143 {
2144 	struct map_rb_node *rb_node;
2145 	struct map *map;
2146 
2147 	down_read(maps__lock(maps));
2148 
2149 
2150 	if (RC_CHK_ACCESS(maps)->last_search_by_name) {
2151 		const struct dso *dso = map__dso(RC_CHK_ACCESS(maps)->last_search_by_name);
2152 
2153 		if (strcmp(dso->short_name, name) == 0) {
2154 			map = RC_CHK_ACCESS(maps)->last_search_by_name;
2155 			goto out_unlock;
2156 		}
2157 	}
2158 	/*
2159 	 * If we have maps->maps_by_name, then the name isn't in the rbtree,
2160 	 * as maps->maps_by_name mirrors the rbtree when lookups by name are
2161 	 * made.
2162 	 */
2163 	map = __maps__find_by_name(maps, name);
2164 	if (map || maps__maps_by_name(maps) != NULL)
2165 		goto out_unlock;
2166 
2167 	/* Fallback to traversing the rbtree... */
2168 	maps__for_each_entry(maps, rb_node) {
2169 		struct dso *dso;
2170 
2171 		map = rb_node->map;
2172 		dso = map__dso(map);
2173 		if (strcmp(dso->short_name, name) == 0) {
2174 			RC_CHK_ACCESS(maps)->last_search_by_name = map;
2175 			goto out_unlock;
2176 		}
2177 	}
2178 	map = NULL;
2179 
2180 out_unlock:
2181 	up_read(maps__lock(maps));
2182 	return map;
2183 }
2184 
2185 int dso__load_vmlinux(struct dso *dso, struct map *map,
2186 		      const char *vmlinux, bool vmlinux_allocated)
2187 {
2188 	int err = -1;
2189 	struct symsrc ss;
2190 	char symfs_vmlinux[PATH_MAX];
2191 	enum dso_binary_type symtab_type;
2192 
2193 	if (vmlinux[0] == '/')
2194 		snprintf(symfs_vmlinux, sizeof(symfs_vmlinux), "%s", vmlinux);
2195 	else
2196 		symbol__join_symfs(symfs_vmlinux, vmlinux);
2197 
2198 	if (dso->kernel == DSO_SPACE__KERNEL_GUEST)
2199 		symtab_type = DSO_BINARY_TYPE__GUEST_VMLINUX;
2200 	else
2201 		symtab_type = DSO_BINARY_TYPE__VMLINUX;
2202 
2203 	if (symsrc__init(&ss, dso, symfs_vmlinux, symtab_type))
2204 		return -1;
2205 
2206 	/*
2207 	 * dso__load_sym() may copy 'dso' which will result in the copies having
2208 	 * an incorrect long name unless we set it here first.
2209 	 */
2210 	dso__set_long_name(dso, vmlinux, vmlinux_allocated);
2211 	if (dso->kernel == DSO_SPACE__KERNEL_GUEST)
2212 		dso->binary_type = DSO_BINARY_TYPE__GUEST_VMLINUX;
2213 	else
2214 		dso->binary_type = DSO_BINARY_TYPE__VMLINUX;
2215 
2216 	err = dso__load_sym(dso, map, &ss, &ss, 0);
2217 	symsrc__destroy(&ss);
2218 
2219 	if (err > 0) {
2220 		dso__set_loaded(dso);
2221 		pr_debug("Using %s for symbols\n", symfs_vmlinux);
2222 	}
2223 
2224 	return err;
2225 }
2226 
2227 int dso__load_vmlinux_path(struct dso *dso, struct map *map)
2228 {
2229 	int i, err = 0;
2230 	char *filename = NULL;
2231 
2232 	pr_debug("Looking at the vmlinux_path (%d entries long)\n",
2233 		 vmlinux_path__nr_entries + 1);
2234 
2235 	for (i = 0; i < vmlinux_path__nr_entries; ++i) {
2236 		err = dso__load_vmlinux(dso, map, vmlinux_path[i], false);
2237 		if (err > 0)
2238 			goto out;
2239 	}
2240 
2241 	if (!symbol_conf.ignore_vmlinux_buildid)
2242 		filename = dso__build_id_filename(dso, NULL, 0, false);
2243 	if (filename != NULL) {
2244 		err = dso__load_vmlinux(dso, map, filename, true);
2245 		if (err > 0)
2246 			goto out;
2247 		free(filename);
2248 	}
2249 out:
2250 	return err;
2251 }
2252 
2253 static bool visible_dir_filter(const char *name, struct dirent *d)
2254 {
2255 	if (d->d_type != DT_DIR)
2256 		return false;
2257 	return lsdir_no_dot_filter(name, d);
2258 }
2259 
2260 static int find_matching_kcore(struct map *map, char *dir, size_t dir_sz)
2261 {
2262 	char kallsyms_filename[PATH_MAX];
2263 	int ret = -1;
2264 	struct strlist *dirs;
2265 	struct str_node *nd;
2266 
2267 	dirs = lsdir(dir, visible_dir_filter);
2268 	if (!dirs)
2269 		return -1;
2270 
2271 	strlist__for_each_entry(nd, dirs) {
2272 		scnprintf(kallsyms_filename, sizeof(kallsyms_filename),
2273 			  "%s/%s/kallsyms", dir, nd->s);
2274 		if (!validate_kcore_addresses(kallsyms_filename, map)) {
2275 			strlcpy(dir, kallsyms_filename, dir_sz);
2276 			ret = 0;
2277 			break;
2278 		}
2279 	}
2280 
2281 	strlist__delete(dirs);
2282 
2283 	return ret;
2284 }
2285 
2286 /*
2287  * Use open(O_RDONLY) to check readability directly instead of access(R_OK)
2288  * since access(R_OK) only checks with real UID/GID but open() use effective
2289  * UID/GID and actual capabilities (e.g. /proc/kcore requires CAP_SYS_RAWIO).
2290  */
2291 static bool filename__readable(const char *file)
2292 {
2293 	int fd = open(file, O_RDONLY);
2294 	if (fd < 0)
2295 		return false;
2296 	close(fd);
2297 	return true;
2298 }
2299 
2300 static char *dso__find_kallsyms(struct dso *dso, struct map *map)
2301 {
2302 	struct build_id bid;
2303 	char sbuild_id[SBUILD_ID_SIZE];
2304 	bool is_host = false;
2305 	char path[PATH_MAX];
2306 
2307 	if (!dso->has_build_id) {
2308 		/*
2309 		 * Last resort, if we don't have a build-id and couldn't find
2310 		 * any vmlinux file, try the running kernel kallsyms table.
2311 		 */
2312 		goto proc_kallsyms;
2313 	}
2314 
2315 	if (sysfs__read_build_id("/sys/kernel/notes", &bid) == 0)
2316 		is_host = dso__build_id_equal(dso, &bid);
2317 
2318 	/* Try a fast path for /proc/kallsyms if possible */
2319 	if (is_host) {
2320 		/*
2321 		 * Do not check the build-id cache, unless we know we cannot use
2322 		 * /proc/kcore or module maps don't match to /proc/kallsyms.
2323 		 * To check readability of /proc/kcore, do not use access(R_OK)
2324 		 * since /proc/kcore requires CAP_SYS_RAWIO to read and access
2325 		 * can't check it.
2326 		 */
2327 		if (filename__readable("/proc/kcore") &&
2328 		    !validate_kcore_addresses("/proc/kallsyms", map))
2329 			goto proc_kallsyms;
2330 	}
2331 
2332 	build_id__sprintf(&dso->bid, sbuild_id);
2333 
2334 	/* Find kallsyms in build-id cache with kcore */
2335 	scnprintf(path, sizeof(path), "%s/%s/%s",
2336 		  buildid_dir, DSO__NAME_KCORE, sbuild_id);
2337 
2338 	if (!find_matching_kcore(map, path, sizeof(path)))
2339 		return strdup(path);
2340 
2341 	/* Use current /proc/kallsyms if possible */
2342 	if (is_host) {
2343 proc_kallsyms:
2344 		return strdup("/proc/kallsyms");
2345 	}
2346 
2347 	/* Finally, find a cache of kallsyms */
2348 	if (!build_id_cache__kallsyms_path(sbuild_id, path, sizeof(path))) {
2349 		pr_err("No kallsyms or vmlinux with build-id %s was found\n",
2350 		       sbuild_id);
2351 		return NULL;
2352 	}
2353 
2354 	return strdup(path);
2355 }
2356 
2357 static int dso__load_kernel_sym(struct dso *dso, struct map *map)
2358 {
2359 	int err;
2360 	const char *kallsyms_filename = NULL;
2361 	char *kallsyms_allocated_filename = NULL;
2362 	char *filename = NULL;
2363 
2364 	/*
2365 	 * Step 1: if the user specified a kallsyms or vmlinux filename, use
2366 	 * it and only it, reporting errors to the user if it cannot be used.
2367 	 *
2368 	 * For instance, try to analyse an ARM perf.data file _without_ a
2369 	 * build-id, or if the user specifies the wrong path to the right
2370 	 * vmlinux file, obviously we can't fallback to another vmlinux (a
2371 	 * x86_86 one, on the machine where analysis is being performed, say),
2372 	 * or worse, /proc/kallsyms.
2373 	 *
2374 	 * If the specified file _has_ a build-id and there is a build-id
2375 	 * section in the perf.data file, we will still do the expected
2376 	 * validation in dso__load_vmlinux and will bail out if they don't
2377 	 * match.
2378 	 */
2379 	if (symbol_conf.kallsyms_name != NULL) {
2380 		kallsyms_filename = symbol_conf.kallsyms_name;
2381 		goto do_kallsyms;
2382 	}
2383 
2384 	if (!symbol_conf.ignore_vmlinux && symbol_conf.vmlinux_name != NULL) {
2385 		return dso__load_vmlinux(dso, map, symbol_conf.vmlinux_name, false);
2386 	}
2387 
2388 	/*
2389 	 * Before checking on common vmlinux locations, check if it's
2390 	 * stored as standard build id binary (not kallsyms) under
2391 	 * .debug cache.
2392 	 */
2393 	if (!symbol_conf.ignore_vmlinux_buildid)
2394 		filename = __dso__build_id_filename(dso, NULL, 0, false, false);
2395 	if (filename != NULL) {
2396 		err = dso__load_vmlinux(dso, map, filename, true);
2397 		if (err > 0)
2398 			return err;
2399 		free(filename);
2400 	}
2401 
2402 	if (!symbol_conf.ignore_vmlinux && vmlinux_path != NULL) {
2403 		err = dso__load_vmlinux_path(dso, map);
2404 		if (err > 0)
2405 			return err;
2406 	}
2407 
2408 	/* do not try local files if a symfs was given */
2409 	if (symbol_conf.symfs[0] != 0)
2410 		return -1;
2411 
2412 	kallsyms_allocated_filename = dso__find_kallsyms(dso, map);
2413 	if (!kallsyms_allocated_filename)
2414 		return -1;
2415 
2416 	kallsyms_filename = kallsyms_allocated_filename;
2417 
2418 do_kallsyms:
2419 	err = dso__load_kallsyms(dso, kallsyms_filename, map);
2420 	if (err > 0)
2421 		pr_debug("Using %s for symbols\n", kallsyms_filename);
2422 	free(kallsyms_allocated_filename);
2423 
2424 	if (err > 0 && !dso__is_kcore(dso)) {
2425 		dso->binary_type = DSO_BINARY_TYPE__KALLSYMS;
2426 		dso__set_long_name(dso, DSO__NAME_KALLSYMS, false);
2427 		map__fixup_start(map);
2428 		map__fixup_end(map);
2429 	}
2430 
2431 	return err;
2432 }
2433 
2434 static int dso__load_guest_kernel_sym(struct dso *dso, struct map *map)
2435 {
2436 	int err;
2437 	const char *kallsyms_filename;
2438 	struct machine *machine = maps__machine(map__kmaps(map));
2439 	char path[PATH_MAX];
2440 
2441 	if (machine->kallsyms_filename) {
2442 		kallsyms_filename = machine->kallsyms_filename;
2443 	} else if (machine__is_default_guest(machine)) {
2444 		/*
2445 		 * if the user specified a vmlinux filename, use it and only
2446 		 * it, reporting errors to the user if it cannot be used.
2447 		 * Or use file guest_kallsyms inputted by user on commandline
2448 		 */
2449 		if (symbol_conf.default_guest_vmlinux_name != NULL) {
2450 			err = dso__load_vmlinux(dso, map,
2451 						symbol_conf.default_guest_vmlinux_name,
2452 						false);
2453 			return err;
2454 		}
2455 
2456 		kallsyms_filename = symbol_conf.default_guest_kallsyms;
2457 		if (!kallsyms_filename)
2458 			return -1;
2459 	} else {
2460 		sprintf(path, "%s/proc/kallsyms", machine->root_dir);
2461 		kallsyms_filename = path;
2462 	}
2463 
2464 	err = dso__load_kallsyms(dso, kallsyms_filename, map);
2465 	if (err > 0)
2466 		pr_debug("Using %s for symbols\n", kallsyms_filename);
2467 	if (err > 0 && !dso__is_kcore(dso)) {
2468 		dso->binary_type = DSO_BINARY_TYPE__GUEST_KALLSYMS;
2469 		dso__set_long_name(dso, machine->mmap_name, false);
2470 		map__fixup_start(map);
2471 		map__fixup_end(map);
2472 	}
2473 
2474 	return err;
2475 }
2476 
2477 static void vmlinux_path__exit(void)
2478 {
2479 	while (--vmlinux_path__nr_entries >= 0)
2480 		zfree(&vmlinux_path[vmlinux_path__nr_entries]);
2481 	vmlinux_path__nr_entries = 0;
2482 
2483 	zfree(&vmlinux_path);
2484 }
2485 
2486 static const char * const vmlinux_paths[] = {
2487 	"vmlinux",
2488 	"/boot/vmlinux"
2489 };
2490 
2491 static const char * const vmlinux_paths_upd[] = {
2492 	"/boot/vmlinux-%s",
2493 	"/usr/lib/debug/boot/vmlinux-%s",
2494 	"/lib/modules/%s/build/vmlinux",
2495 	"/usr/lib/debug/lib/modules/%s/vmlinux",
2496 	"/usr/lib/debug/boot/vmlinux-%s.debug"
2497 };
2498 
2499 static int vmlinux_path__add(const char *new_entry)
2500 {
2501 	vmlinux_path[vmlinux_path__nr_entries] = strdup(new_entry);
2502 	if (vmlinux_path[vmlinux_path__nr_entries] == NULL)
2503 		return -1;
2504 	++vmlinux_path__nr_entries;
2505 
2506 	return 0;
2507 }
2508 
2509 static int vmlinux_path__init(struct perf_env *env)
2510 {
2511 	struct utsname uts;
2512 	char bf[PATH_MAX];
2513 	char *kernel_version;
2514 	unsigned int i;
2515 
2516 	vmlinux_path = malloc(sizeof(char *) * (ARRAY_SIZE(vmlinux_paths) +
2517 			      ARRAY_SIZE(vmlinux_paths_upd)));
2518 	if (vmlinux_path == NULL)
2519 		return -1;
2520 
2521 	for (i = 0; i < ARRAY_SIZE(vmlinux_paths); i++)
2522 		if (vmlinux_path__add(vmlinux_paths[i]) < 0)
2523 			goto out_fail;
2524 
2525 	/* only try kernel version if no symfs was given */
2526 	if (symbol_conf.symfs[0] != 0)
2527 		return 0;
2528 
2529 	if (env) {
2530 		kernel_version = env->os_release;
2531 	} else {
2532 		if (uname(&uts) < 0)
2533 			goto out_fail;
2534 
2535 		kernel_version = uts.release;
2536 	}
2537 
2538 	for (i = 0; i < ARRAY_SIZE(vmlinux_paths_upd); i++) {
2539 		snprintf(bf, sizeof(bf), vmlinux_paths_upd[i], kernel_version);
2540 		if (vmlinux_path__add(bf) < 0)
2541 			goto out_fail;
2542 	}
2543 
2544 	return 0;
2545 
2546 out_fail:
2547 	vmlinux_path__exit();
2548 	return -1;
2549 }
2550 
2551 int setup_list(struct strlist **list, const char *list_str,
2552 		      const char *list_name)
2553 {
2554 	if (list_str == NULL)
2555 		return 0;
2556 
2557 	*list = strlist__new(list_str, NULL);
2558 	if (!*list) {
2559 		pr_err("problems parsing %s list\n", list_name);
2560 		return -1;
2561 	}
2562 
2563 	symbol_conf.has_filter = true;
2564 	return 0;
2565 }
2566 
2567 int setup_intlist(struct intlist **list, const char *list_str,
2568 		  const char *list_name)
2569 {
2570 	if (list_str == NULL)
2571 		return 0;
2572 
2573 	*list = intlist__new(list_str);
2574 	if (!*list) {
2575 		pr_err("problems parsing %s list\n", list_name);
2576 		return -1;
2577 	}
2578 	return 0;
2579 }
2580 
2581 static int setup_addrlist(struct intlist **addr_list, struct strlist *sym_list)
2582 {
2583 	struct str_node *pos, *tmp;
2584 	unsigned long val;
2585 	char *sep;
2586 	const char *end;
2587 	int i = 0, err;
2588 
2589 	*addr_list = intlist__new(NULL);
2590 	if (!*addr_list)
2591 		return -1;
2592 
2593 	strlist__for_each_entry_safe(pos, tmp, sym_list) {
2594 		errno = 0;
2595 		val = strtoul(pos->s, &sep, 16);
2596 		if (errno || (sep == pos->s))
2597 			continue;
2598 
2599 		if (*sep != '\0') {
2600 			end = pos->s + strlen(pos->s) - 1;
2601 			while (end >= sep && isspace(*end))
2602 				end--;
2603 
2604 			if (end >= sep)
2605 				continue;
2606 		}
2607 
2608 		err = intlist__add(*addr_list, val);
2609 		if (err)
2610 			break;
2611 
2612 		strlist__remove(sym_list, pos);
2613 		i++;
2614 	}
2615 
2616 	if (i == 0) {
2617 		intlist__delete(*addr_list);
2618 		*addr_list = NULL;
2619 	}
2620 
2621 	return 0;
2622 }
2623 
2624 static bool symbol__read_kptr_restrict(void)
2625 {
2626 	bool value = false;
2627 	FILE *fp = fopen("/proc/sys/kernel/kptr_restrict", "r");
2628 
2629 	if (fp != NULL) {
2630 		char line[8];
2631 
2632 		if (fgets(line, sizeof(line), fp) != NULL)
2633 			value = perf_cap__capable(CAP_SYSLOG) ?
2634 					(atoi(line) >= 2) :
2635 					(atoi(line) != 0);
2636 
2637 		fclose(fp);
2638 	}
2639 
2640 	/* Per kernel/kallsyms.c:
2641 	 * we also restrict when perf_event_paranoid > 1 w/o CAP_SYSLOG
2642 	 */
2643 	if (perf_event_paranoid() > 1 && !perf_cap__capable(CAP_SYSLOG))
2644 		value = true;
2645 
2646 	return value;
2647 }
2648 
2649 int symbol__annotation_init(void)
2650 {
2651 	if (symbol_conf.init_annotation)
2652 		return 0;
2653 
2654 	if (symbol_conf.initialized) {
2655 		pr_err("Annotation needs to be init before symbol__init()\n");
2656 		return -1;
2657 	}
2658 
2659 	symbol_conf.priv_size += sizeof(struct annotation);
2660 	symbol_conf.init_annotation = true;
2661 	return 0;
2662 }
2663 
2664 int symbol__init(struct perf_env *env)
2665 {
2666 	const char *symfs;
2667 
2668 	if (symbol_conf.initialized)
2669 		return 0;
2670 
2671 	symbol_conf.priv_size = PERF_ALIGN(symbol_conf.priv_size, sizeof(u64));
2672 
2673 	symbol__elf_init();
2674 
2675 	if (symbol_conf.try_vmlinux_path && vmlinux_path__init(env) < 0)
2676 		return -1;
2677 
2678 	if (symbol_conf.field_sep && *symbol_conf.field_sep == '.') {
2679 		pr_err("'.' is the only non valid --field-separator argument\n");
2680 		return -1;
2681 	}
2682 
2683 	if (setup_list(&symbol_conf.dso_list,
2684 		       symbol_conf.dso_list_str, "dso") < 0)
2685 		return -1;
2686 
2687 	if (setup_list(&symbol_conf.comm_list,
2688 		       symbol_conf.comm_list_str, "comm") < 0)
2689 		goto out_free_dso_list;
2690 
2691 	if (setup_intlist(&symbol_conf.pid_list,
2692 		       symbol_conf.pid_list_str, "pid") < 0)
2693 		goto out_free_comm_list;
2694 
2695 	if (setup_intlist(&symbol_conf.tid_list,
2696 		       symbol_conf.tid_list_str, "tid") < 0)
2697 		goto out_free_pid_list;
2698 
2699 	if (setup_list(&symbol_conf.sym_list,
2700 		       symbol_conf.sym_list_str, "symbol") < 0)
2701 		goto out_free_tid_list;
2702 
2703 	if (symbol_conf.sym_list &&
2704 	    setup_addrlist(&symbol_conf.addr_list, symbol_conf.sym_list) < 0)
2705 		goto out_free_sym_list;
2706 
2707 	if (setup_list(&symbol_conf.bt_stop_list,
2708 		       symbol_conf.bt_stop_list_str, "symbol") < 0)
2709 		goto out_free_sym_list;
2710 
2711 	/*
2712 	 * A path to symbols of "/" is identical to ""
2713 	 * reset here for simplicity.
2714 	 */
2715 	symfs = realpath(symbol_conf.symfs, NULL);
2716 	if (symfs == NULL)
2717 		symfs = symbol_conf.symfs;
2718 	if (strcmp(symfs, "/") == 0)
2719 		symbol_conf.symfs = "";
2720 	if (symfs != symbol_conf.symfs)
2721 		free((void *)symfs);
2722 
2723 	symbol_conf.kptr_restrict = symbol__read_kptr_restrict();
2724 
2725 	symbol_conf.initialized = true;
2726 	return 0;
2727 
2728 out_free_sym_list:
2729 	strlist__delete(symbol_conf.sym_list);
2730 	intlist__delete(symbol_conf.addr_list);
2731 out_free_tid_list:
2732 	intlist__delete(symbol_conf.tid_list);
2733 out_free_pid_list:
2734 	intlist__delete(symbol_conf.pid_list);
2735 out_free_comm_list:
2736 	strlist__delete(symbol_conf.comm_list);
2737 out_free_dso_list:
2738 	strlist__delete(symbol_conf.dso_list);
2739 	return -1;
2740 }
2741 
2742 void symbol__exit(void)
2743 {
2744 	if (!symbol_conf.initialized)
2745 		return;
2746 	strlist__delete(symbol_conf.bt_stop_list);
2747 	strlist__delete(symbol_conf.sym_list);
2748 	strlist__delete(symbol_conf.dso_list);
2749 	strlist__delete(symbol_conf.comm_list);
2750 	intlist__delete(symbol_conf.tid_list);
2751 	intlist__delete(symbol_conf.pid_list);
2752 	intlist__delete(symbol_conf.addr_list);
2753 	vmlinux_path__exit();
2754 	symbol_conf.sym_list = symbol_conf.dso_list = symbol_conf.comm_list = NULL;
2755 	symbol_conf.bt_stop_list = NULL;
2756 	symbol_conf.initialized = false;
2757 }
2758 
2759 int symbol__config_symfs(const struct option *opt __maybe_unused,
2760 			 const char *dir, int unset __maybe_unused)
2761 {
2762 	char *bf = NULL;
2763 	int ret;
2764 
2765 	symbol_conf.symfs = strdup(dir);
2766 	if (symbol_conf.symfs == NULL)
2767 		return -ENOMEM;
2768 
2769 	/* skip the locally configured cache if a symfs is given, and
2770 	 * config buildid dir to symfs/.debug
2771 	 */
2772 	ret = asprintf(&bf, "%s/%s", dir, ".debug");
2773 	if (ret < 0)
2774 		return -ENOMEM;
2775 
2776 	set_buildid_dir(bf);
2777 
2778 	free(bf);
2779 	return 0;
2780 }
2781 
2782 struct mem_info *mem_info__get(struct mem_info *mi)
2783 {
2784 	if (mi)
2785 		refcount_inc(&mi->refcnt);
2786 	return mi;
2787 }
2788 
2789 void mem_info__put(struct mem_info *mi)
2790 {
2791 	if (mi && refcount_dec_and_test(&mi->refcnt))
2792 		free(mi);
2793 }
2794 
2795 struct mem_info *mem_info__new(void)
2796 {
2797 	struct mem_info *mi = zalloc(sizeof(*mi));
2798 
2799 	if (mi)
2800 		refcount_set(&mi->refcnt, 1);
2801 	return mi;
2802 }
2803 
2804 /*
2805  * Checks that user supplied symbol kernel files are accessible because
2806  * the default mechanism for accessing elf files fails silently. i.e. if
2807  * debug syms for a build ID aren't found perf carries on normally. When
2808  * they are user supplied we should assume that the user doesn't want to
2809  * silently fail.
2810  */
2811 int symbol__validate_sym_arguments(void)
2812 {
2813 	if (symbol_conf.vmlinux_name &&
2814 	    access(symbol_conf.vmlinux_name, R_OK)) {
2815 		pr_err("Invalid file: %s\n", symbol_conf.vmlinux_name);
2816 		return -EINVAL;
2817 	}
2818 	if (symbol_conf.kallsyms_name &&
2819 	    access(symbol_conf.kallsyms_name, R_OK)) {
2820 		pr_err("Invalid file: %s\n", symbol_conf.kallsyms_name);
2821 		return -EINVAL;
2822 	}
2823 	return 0;
2824 }
2825