xref: /linux/tools/perf/util/symbol.c (revision 84b9b44b)
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 		next = rb_entry(nd, struct symbol, rb_node);
206 
207 		if (!nd)
208 			break;
209 
210 		if (curr->start != next->start)
211 			continue;
212 
213 		if (choose_best_symbol(curr, next) == SYMBOL_A) {
214 			if (next->type == STT_GNU_IFUNC)
215 				curr->ifunc_alias = true;
216 			rb_erase_cached(&next->rb_node, symbols);
217 			symbol__delete(next);
218 			goto again;
219 		} else {
220 			if (curr->type == STT_GNU_IFUNC)
221 				next->ifunc_alias = true;
222 			nd = rb_next(&curr->rb_node);
223 			rb_erase_cached(&curr->rb_node, symbols);
224 			symbol__delete(curr);
225 		}
226 	}
227 }
228 
229 /* Update zero-sized symbols using the address of the next symbol */
230 void symbols__fixup_end(struct rb_root_cached *symbols, bool is_kallsyms)
231 {
232 	struct rb_node *nd, *prevnd = rb_first_cached(symbols);
233 	struct symbol *curr, *prev;
234 
235 	if (prevnd == NULL)
236 		return;
237 
238 	curr = rb_entry(prevnd, struct symbol, rb_node);
239 
240 	for (nd = rb_next(prevnd); nd; nd = rb_next(nd)) {
241 		prev = curr;
242 		curr = rb_entry(nd, struct symbol, rb_node);
243 
244 		/*
245 		 * On some architecture kernel text segment start is located at
246 		 * some low memory address, while modules are located at high
247 		 * memory addresses (or vice versa).  The gap between end of
248 		 * kernel text segment and beginning of first module's text
249 		 * segment is very big.  Therefore do not fill this gap and do
250 		 * not assign it to the kernel dso map (kallsyms).
251 		 *
252 		 * In kallsyms, it determines module symbols using '[' character
253 		 * like in:
254 		 *   ffffffffc1937000 T hdmi_driver_init  [snd_hda_codec_hdmi]
255 		 */
256 		if (prev->end == prev->start) {
257 			/* Last kernel/module symbol mapped to end of page */
258 			if (is_kallsyms && (!strchr(prev->name, '[') !=
259 					    !strchr(curr->name, '[')))
260 				prev->end = roundup(prev->end + 4096, 4096);
261 			else
262 				prev->end = curr->start;
263 
264 			pr_debug4("%s sym:%s end:%#" PRIx64 "\n",
265 				  __func__, prev->name, prev->end);
266 		}
267 	}
268 
269 	/* Last entry */
270 	if (curr->end == curr->start)
271 		curr->end = roundup(curr->start, 4096) + 4096;
272 }
273 
274 void maps__fixup_end(struct maps *maps)
275 {
276 	struct map_rb_node *prev = NULL, *curr;
277 
278 	down_write(maps__lock(maps));
279 
280 	maps__for_each_entry(maps, curr) {
281 		if (prev != NULL && !map__end(prev->map))
282 			map__set_end(prev->map, map__start(curr->map));
283 
284 		prev = curr;
285 	}
286 
287 	/*
288 	 * We still haven't the actual symbols, so guess the
289 	 * last map final address.
290 	 */
291 	if (curr && !map__end(curr->map))
292 		map__set_end(curr->map, ~0ULL);
293 
294 	up_write(maps__lock(maps));
295 }
296 
297 struct symbol *symbol__new(u64 start, u64 len, u8 binding, u8 type, const char *name)
298 {
299 	size_t namelen = strlen(name) + 1;
300 	struct symbol *sym = calloc(1, (symbol_conf.priv_size +
301 					sizeof(*sym) + namelen));
302 	if (sym == NULL)
303 		return NULL;
304 
305 	if (symbol_conf.priv_size) {
306 		if (symbol_conf.init_annotation) {
307 			struct annotation *notes = (void *)sym;
308 			annotation__init(notes);
309 		}
310 		sym = ((void *)sym) + symbol_conf.priv_size;
311 	}
312 
313 	sym->start   = start;
314 	sym->end     = len ? start + len : start;
315 	sym->type    = type;
316 	sym->binding = binding;
317 	sym->namelen = namelen - 1;
318 
319 	pr_debug4("%s: %s %#" PRIx64 "-%#" PRIx64 "\n",
320 		  __func__, name, start, sym->end);
321 	memcpy(sym->name, name, namelen);
322 
323 	return sym;
324 }
325 
326 void symbol__delete(struct symbol *sym)
327 {
328 	if (symbol_conf.priv_size) {
329 		if (symbol_conf.init_annotation) {
330 			struct annotation *notes = symbol__annotation(sym);
331 
332 			annotation__exit(notes);
333 		}
334 	}
335 	free(((void *)sym) - symbol_conf.priv_size);
336 }
337 
338 void symbols__delete(struct rb_root_cached *symbols)
339 {
340 	struct symbol *pos;
341 	struct rb_node *next = rb_first_cached(symbols);
342 
343 	while (next) {
344 		pos = rb_entry(next, struct symbol, rb_node);
345 		next = rb_next(&pos->rb_node);
346 		rb_erase_cached(&pos->rb_node, symbols);
347 		symbol__delete(pos);
348 	}
349 }
350 
351 void __symbols__insert(struct rb_root_cached *symbols,
352 		       struct symbol *sym, bool kernel)
353 {
354 	struct rb_node **p = &symbols->rb_root.rb_node;
355 	struct rb_node *parent = NULL;
356 	const u64 ip = sym->start;
357 	struct symbol *s;
358 	bool leftmost = true;
359 
360 	if (kernel) {
361 		const char *name = sym->name;
362 		/*
363 		 * ppc64 uses function descriptors and appends a '.' to the
364 		 * start of every instruction address. Remove it.
365 		 */
366 		if (name[0] == '.')
367 			name++;
368 		sym->idle = symbol__is_idle(name);
369 	}
370 
371 	while (*p != NULL) {
372 		parent = *p;
373 		s = rb_entry(parent, struct symbol, rb_node);
374 		if (ip < s->start)
375 			p = &(*p)->rb_left;
376 		else {
377 			p = &(*p)->rb_right;
378 			leftmost = false;
379 		}
380 	}
381 	rb_link_node(&sym->rb_node, parent, p);
382 	rb_insert_color_cached(&sym->rb_node, symbols, leftmost);
383 }
384 
385 void symbols__insert(struct rb_root_cached *symbols, struct symbol *sym)
386 {
387 	__symbols__insert(symbols, sym, false);
388 }
389 
390 static struct symbol *symbols__find(struct rb_root_cached *symbols, u64 ip)
391 {
392 	struct rb_node *n;
393 
394 	if (symbols == NULL)
395 		return NULL;
396 
397 	n = symbols->rb_root.rb_node;
398 
399 	while (n) {
400 		struct symbol *s = rb_entry(n, struct symbol, rb_node);
401 
402 		if (ip < s->start)
403 			n = n->rb_left;
404 		else if (ip > s->end || (ip == s->end && ip != s->start))
405 			n = n->rb_right;
406 		else
407 			return s;
408 	}
409 
410 	return NULL;
411 }
412 
413 static struct symbol *symbols__first(struct rb_root_cached *symbols)
414 {
415 	struct rb_node *n = rb_first_cached(symbols);
416 
417 	if (n)
418 		return rb_entry(n, struct symbol, rb_node);
419 
420 	return NULL;
421 }
422 
423 static struct symbol *symbols__last(struct rb_root_cached *symbols)
424 {
425 	struct rb_node *n = rb_last(&symbols->rb_root);
426 
427 	if (n)
428 		return rb_entry(n, struct symbol, rb_node);
429 
430 	return NULL;
431 }
432 
433 static struct symbol *symbols__next(struct symbol *sym)
434 {
435 	struct rb_node *n = rb_next(&sym->rb_node);
436 
437 	if (n)
438 		return rb_entry(n, struct symbol, rb_node);
439 
440 	return NULL;
441 }
442 
443 static void symbols__insert_by_name(struct rb_root_cached *symbols, struct symbol *sym)
444 {
445 	struct rb_node **p = &symbols->rb_root.rb_node;
446 	struct rb_node *parent = NULL;
447 	struct symbol_name_rb_node *symn, *s;
448 	bool leftmost = true;
449 
450 	symn = container_of(sym, struct symbol_name_rb_node, sym);
451 
452 	while (*p != NULL) {
453 		parent = *p;
454 		s = rb_entry(parent, struct symbol_name_rb_node, rb_node);
455 		if (strcmp(sym->name, s->sym.name) < 0)
456 			p = &(*p)->rb_left;
457 		else {
458 			p = &(*p)->rb_right;
459 			leftmost = false;
460 		}
461 	}
462 	rb_link_node(&symn->rb_node, parent, p);
463 	rb_insert_color_cached(&symn->rb_node, symbols, leftmost);
464 }
465 
466 static void symbols__sort_by_name(struct rb_root_cached *symbols,
467 				  struct rb_root_cached *source)
468 {
469 	struct rb_node *nd;
470 
471 	for (nd = rb_first_cached(source); nd; nd = rb_next(nd)) {
472 		struct symbol *pos = rb_entry(nd, struct symbol, rb_node);
473 		symbols__insert_by_name(symbols, pos);
474 	}
475 }
476 
477 int symbol__match_symbol_name(const char *name, const char *str,
478 			      enum symbol_tag_include includes)
479 {
480 	const char *versioning;
481 
482 	if (includes == SYMBOL_TAG_INCLUDE__DEFAULT_ONLY &&
483 	    (versioning = strstr(name, "@@"))) {
484 		int len = strlen(str);
485 
486 		if (len < versioning - name)
487 			len = versioning - name;
488 
489 		return arch__compare_symbol_names_n(name, str, len);
490 	} else
491 		return arch__compare_symbol_names(name, str);
492 }
493 
494 static struct symbol *symbols__find_by_name(struct rb_root_cached *symbols,
495 					    const char *name,
496 					    enum symbol_tag_include includes)
497 {
498 	struct rb_node *n;
499 	struct symbol_name_rb_node *s = NULL;
500 
501 	if (symbols == NULL)
502 		return NULL;
503 
504 	n = symbols->rb_root.rb_node;
505 
506 	while (n) {
507 		int cmp;
508 
509 		s = rb_entry(n, struct symbol_name_rb_node, rb_node);
510 		cmp = symbol__match_symbol_name(s->sym.name, name, includes);
511 
512 		if (cmp > 0)
513 			n = n->rb_left;
514 		else if (cmp < 0)
515 			n = n->rb_right;
516 		else
517 			break;
518 	}
519 
520 	if (n == NULL)
521 		return NULL;
522 
523 	if (includes != SYMBOL_TAG_INCLUDE__DEFAULT_ONLY)
524 		/* return first symbol that has same name (if any) */
525 		for (n = rb_prev(n); n; n = rb_prev(n)) {
526 			struct symbol_name_rb_node *tmp;
527 
528 			tmp = rb_entry(n, struct symbol_name_rb_node, rb_node);
529 			if (arch__compare_symbol_names(tmp->sym.name, s->sym.name))
530 				break;
531 
532 			s = tmp;
533 		}
534 
535 	return &s->sym;
536 }
537 
538 void dso__reset_find_symbol_cache(struct dso *dso)
539 {
540 	dso->last_find_result.addr   = 0;
541 	dso->last_find_result.symbol = NULL;
542 }
543 
544 void dso__insert_symbol(struct dso *dso, struct symbol *sym)
545 {
546 	__symbols__insert(&dso->symbols, sym, dso->kernel);
547 
548 	/* update the symbol cache if necessary */
549 	if (dso->last_find_result.addr >= sym->start &&
550 	    (dso->last_find_result.addr < sym->end ||
551 	    sym->start == sym->end)) {
552 		dso->last_find_result.symbol = sym;
553 	}
554 }
555 
556 void dso__delete_symbol(struct dso *dso, struct symbol *sym)
557 {
558 	rb_erase_cached(&sym->rb_node, &dso->symbols);
559 	symbol__delete(sym);
560 	dso__reset_find_symbol_cache(dso);
561 }
562 
563 struct symbol *dso__find_symbol(struct dso *dso, u64 addr)
564 {
565 	if (dso->last_find_result.addr != addr || dso->last_find_result.symbol == NULL) {
566 		dso->last_find_result.addr   = addr;
567 		dso->last_find_result.symbol = symbols__find(&dso->symbols, addr);
568 	}
569 
570 	return dso->last_find_result.symbol;
571 }
572 
573 struct symbol *dso__find_symbol_nocache(struct dso *dso, u64 addr)
574 {
575 	return symbols__find(&dso->symbols, addr);
576 }
577 
578 struct symbol *dso__first_symbol(struct dso *dso)
579 {
580 	return symbols__first(&dso->symbols);
581 }
582 
583 struct symbol *dso__last_symbol(struct dso *dso)
584 {
585 	return symbols__last(&dso->symbols);
586 }
587 
588 struct symbol *dso__next_symbol(struct symbol *sym)
589 {
590 	return symbols__next(sym);
591 }
592 
593 struct symbol *symbol__next_by_name(struct symbol *sym)
594 {
595 	struct symbol_name_rb_node *s = container_of(sym, struct symbol_name_rb_node, sym);
596 	struct rb_node *n = rb_next(&s->rb_node);
597 
598 	return n ? &rb_entry(n, struct symbol_name_rb_node, rb_node)->sym : NULL;
599 }
600 
601  /*
602   * Returns first symbol that matched with @name.
603   */
604 struct symbol *dso__find_symbol_by_name(struct dso *dso, const char *name)
605 {
606 	struct symbol *s = symbols__find_by_name(&dso->symbol_names, name,
607 						 SYMBOL_TAG_INCLUDE__NONE);
608 	if (!s)
609 		s = symbols__find_by_name(&dso->symbol_names, name,
610 					  SYMBOL_TAG_INCLUDE__DEFAULT_ONLY);
611 	return s;
612 }
613 
614 void dso__sort_by_name(struct dso *dso)
615 {
616 	dso__set_sorted_by_name(dso);
617 	return symbols__sort_by_name(&dso->symbol_names, &dso->symbols);
618 }
619 
620 /*
621  * While we find nice hex chars, build a long_val.
622  * Return number of chars processed.
623  */
624 static int hex2u64(const char *ptr, u64 *long_val)
625 {
626 	char *p;
627 
628 	*long_val = strtoull(ptr, &p, 16);
629 
630 	return p - ptr;
631 }
632 
633 
634 int modules__parse(const char *filename, void *arg,
635 		   int (*process_module)(void *arg, const char *name,
636 					 u64 start, u64 size))
637 {
638 	char *line = NULL;
639 	size_t n;
640 	FILE *file;
641 	int err = 0;
642 
643 	file = fopen(filename, "r");
644 	if (file == NULL)
645 		return -1;
646 
647 	while (1) {
648 		char name[PATH_MAX];
649 		u64 start, size;
650 		char *sep, *endptr;
651 		ssize_t line_len;
652 
653 		line_len = getline(&line, &n, file);
654 		if (line_len < 0) {
655 			if (feof(file))
656 				break;
657 			err = -1;
658 			goto out;
659 		}
660 
661 		if (!line) {
662 			err = -1;
663 			goto out;
664 		}
665 
666 		line[--line_len] = '\0'; /* \n */
667 
668 		sep = strrchr(line, 'x');
669 		if (sep == NULL)
670 			continue;
671 
672 		hex2u64(sep + 1, &start);
673 
674 		sep = strchr(line, ' ');
675 		if (sep == NULL)
676 			continue;
677 
678 		*sep = '\0';
679 
680 		scnprintf(name, sizeof(name), "[%s]", line);
681 
682 		size = strtoul(sep + 1, &endptr, 0);
683 		if (*endptr != ' ' && *endptr != '\t')
684 			continue;
685 
686 		err = process_module(arg, name, start, size);
687 		if (err)
688 			break;
689 	}
690 out:
691 	free(line);
692 	fclose(file);
693 	return err;
694 }
695 
696 /*
697  * These are symbols in the kernel image, so make sure that
698  * sym is from a kernel DSO.
699  */
700 static bool symbol__is_idle(const char *name)
701 {
702 	const char * const idle_symbols[] = {
703 		"acpi_idle_do_entry",
704 		"acpi_processor_ffh_cstate_enter",
705 		"arch_cpu_idle",
706 		"cpu_idle",
707 		"cpu_startup_entry",
708 		"idle_cpu",
709 		"intel_idle",
710 		"default_idle",
711 		"native_safe_halt",
712 		"enter_idle",
713 		"exit_idle",
714 		"mwait_idle",
715 		"mwait_idle_with_hints",
716 		"mwait_idle_with_hints.constprop.0",
717 		"poll_idle",
718 		"ppc64_runlatch_off",
719 		"pseries_dedicated_idle_sleep",
720 		"psw_idle",
721 		"psw_idle_exit",
722 		NULL
723 	};
724 	int i;
725 	static struct strlist *idle_symbols_list;
726 
727 	if (idle_symbols_list)
728 		return strlist__has_entry(idle_symbols_list, name);
729 
730 	idle_symbols_list = strlist__new(NULL, NULL);
731 
732 	for (i = 0; idle_symbols[i]; i++)
733 		strlist__add(idle_symbols_list, idle_symbols[i]);
734 
735 	return strlist__has_entry(idle_symbols_list, name);
736 }
737 
738 static int map__process_kallsym_symbol(void *arg, const char *name,
739 				       char type, u64 start)
740 {
741 	struct symbol *sym;
742 	struct dso *dso = arg;
743 	struct rb_root_cached *root = &dso->symbols;
744 
745 	if (!symbol_type__filter(type))
746 		return 0;
747 
748 	/* Ignore local symbols for ARM modules */
749 	if (name[0] == '$')
750 		return 0;
751 
752 	/*
753 	 * module symbols are not sorted so we add all
754 	 * symbols, setting length to 0, and rely on
755 	 * symbols__fixup_end() to fix it up.
756 	 */
757 	sym = symbol__new(start, 0, kallsyms2elf_binding(type), kallsyms2elf_type(type), name);
758 	if (sym == NULL)
759 		return -ENOMEM;
760 	/*
761 	 * We will pass the symbols to the filter later, in
762 	 * map__split_kallsyms, when we have split the maps per module
763 	 */
764 	__symbols__insert(root, sym, !strchr(name, '['));
765 
766 	return 0;
767 }
768 
769 /*
770  * Loads the function entries in /proc/kallsyms into kernel_map->dso,
771  * so that we can in the next step set the symbol ->end address and then
772  * call kernel_maps__split_kallsyms.
773  */
774 static int dso__load_all_kallsyms(struct dso *dso, const char *filename)
775 {
776 	return kallsyms__parse(filename, dso, map__process_kallsym_symbol);
777 }
778 
779 static int maps__split_kallsyms_for_kcore(struct maps *kmaps, struct dso *dso)
780 {
781 	struct map *curr_map;
782 	struct symbol *pos;
783 	int count = 0;
784 	struct rb_root_cached old_root = dso->symbols;
785 	struct rb_root_cached *root = &dso->symbols;
786 	struct rb_node *next = rb_first_cached(root);
787 
788 	if (!kmaps)
789 		return -1;
790 
791 	*root = RB_ROOT_CACHED;
792 
793 	while (next) {
794 		struct dso *curr_map_dso;
795 		char *module;
796 
797 		pos = rb_entry(next, struct symbol, rb_node);
798 		next = rb_next(&pos->rb_node);
799 
800 		rb_erase_cached(&pos->rb_node, &old_root);
801 		RB_CLEAR_NODE(&pos->rb_node);
802 		module = strchr(pos->name, '\t');
803 		if (module)
804 			*module = '\0';
805 
806 		curr_map = maps__find(kmaps, pos->start);
807 
808 		if (!curr_map) {
809 			symbol__delete(pos);
810 			continue;
811 		}
812 		curr_map_dso = map__dso(curr_map);
813 		pos->start -= map__start(curr_map) - map__pgoff(curr_map);
814 		if (pos->end > map__end(curr_map))
815 			pos->end = map__end(curr_map);
816 		if (pos->end)
817 			pos->end -= map__start(curr_map) - map__pgoff(curr_map);
818 		symbols__insert(&curr_map_dso->symbols, pos);
819 		++count;
820 	}
821 
822 	/* Symbols have been adjusted */
823 	dso->adjust_symbols = 1;
824 
825 	return count;
826 }
827 
828 /*
829  * Split the symbols into maps, making sure there are no overlaps, i.e. the
830  * kernel range is broken in several maps, named [kernel].N, as we don't have
831  * the original ELF section names vmlinux have.
832  */
833 static int maps__split_kallsyms(struct maps *kmaps, struct dso *dso, u64 delta,
834 				struct map *initial_map)
835 {
836 	struct machine *machine;
837 	struct map *curr_map = initial_map;
838 	struct symbol *pos;
839 	int count = 0, moved = 0;
840 	struct rb_root_cached *root = &dso->symbols;
841 	struct rb_node *next = rb_first_cached(root);
842 	int kernel_range = 0;
843 	bool x86_64;
844 
845 	if (!kmaps)
846 		return -1;
847 
848 	machine = maps__machine(kmaps);
849 
850 	x86_64 = machine__is(machine, "x86_64");
851 
852 	while (next) {
853 		char *module;
854 
855 		pos = rb_entry(next, struct symbol, rb_node);
856 		next = rb_next(&pos->rb_node);
857 
858 		module = strchr(pos->name, '\t');
859 		if (module) {
860 			struct dso *curr_map_dso;
861 
862 			if (!symbol_conf.use_modules)
863 				goto discard_symbol;
864 
865 			*module++ = '\0';
866 			curr_map_dso = map__dso(curr_map);
867 			if (strcmp(curr_map_dso->short_name, module)) {
868 				if (RC_CHK_ACCESS(curr_map) != RC_CHK_ACCESS(initial_map) &&
869 				    dso->kernel == DSO_SPACE__KERNEL_GUEST &&
870 				    machine__is_default_guest(machine)) {
871 					/*
872 					 * We assume all symbols of a module are
873 					 * continuous in * kallsyms, so curr_map
874 					 * points to a module and all its
875 					 * symbols are in its kmap. Mark it as
876 					 * loaded.
877 					 */
878 					dso__set_loaded(curr_map_dso);
879 				}
880 
881 				curr_map = maps__find_by_name(kmaps, module);
882 				if (curr_map == NULL) {
883 					pr_debug("%s/proc/{kallsyms,modules} "
884 					         "inconsistency while looking "
885 						 "for \"%s\" module!\n",
886 						 machine->root_dir, module);
887 					curr_map = initial_map;
888 					goto discard_symbol;
889 				}
890 				curr_map_dso = map__dso(curr_map);
891 				if (curr_map_dso->loaded &&
892 				    !machine__is_default_guest(machine))
893 					goto discard_symbol;
894 			}
895 			/*
896 			 * So that we look just like we get from .ko files,
897 			 * i.e. not prelinked, relative to initial_map->start.
898 			 */
899 			pos->start = map__map_ip(curr_map, pos->start);
900 			pos->end   = map__map_ip(curr_map, pos->end);
901 		} else if (x86_64 && is_entry_trampoline(pos->name)) {
902 			/*
903 			 * These symbols are not needed anymore since the
904 			 * trampoline maps refer to the text section and it's
905 			 * symbols instead. Avoid having to deal with
906 			 * relocations, and the assumption that the first symbol
907 			 * is the start of kernel text, by simply removing the
908 			 * symbols at this point.
909 			 */
910 			goto discard_symbol;
911 		} else if (curr_map != initial_map) {
912 			char dso_name[PATH_MAX];
913 			struct dso *ndso;
914 
915 			if (delta) {
916 				/* Kernel was relocated at boot time */
917 				pos->start -= delta;
918 				pos->end -= delta;
919 			}
920 
921 			if (count == 0) {
922 				curr_map = initial_map;
923 				goto add_symbol;
924 			}
925 
926 			if (dso->kernel == DSO_SPACE__KERNEL_GUEST)
927 				snprintf(dso_name, sizeof(dso_name),
928 					"[guest.kernel].%d",
929 					kernel_range++);
930 			else
931 				snprintf(dso_name, sizeof(dso_name),
932 					"[kernel].%d",
933 					kernel_range++);
934 
935 			ndso = dso__new(dso_name);
936 			if (ndso == NULL)
937 				return -1;
938 
939 			ndso->kernel = dso->kernel;
940 
941 			curr_map = map__new2(pos->start, ndso);
942 			if (curr_map == NULL) {
943 				dso__put(ndso);
944 				return -1;
945 			}
946 
947 			map__set_map_ip(curr_map, identity__map_ip);
948 			map__set_unmap_ip(curr_map, identity__map_ip);
949 			if (maps__insert(kmaps, curr_map)) {
950 				dso__put(ndso);
951 				return -1;
952 			}
953 			++kernel_range;
954 		} else if (delta) {
955 			/* Kernel was relocated at boot time */
956 			pos->start -= delta;
957 			pos->end -= delta;
958 		}
959 add_symbol:
960 		if (curr_map != initial_map) {
961 			struct dso *curr_map_dso = map__dso(curr_map);
962 
963 			rb_erase_cached(&pos->rb_node, root);
964 			symbols__insert(&curr_map_dso->symbols, pos);
965 			++moved;
966 		} else
967 			++count;
968 
969 		continue;
970 discard_symbol:
971 		rb_erase_cached(&pos->rb_node, root);
972 		symbol__delete(pos);
973 	}
974 
975 	if (curr_map != initial_map &&
976 	    dso->kernel == DSO_SPACE__KERNEL_GUEST &&
977 	    machine__is_default_guest(maps__machine(kmaps))) {
978 		dso__set_loaded(map__dso(curr_map));
979 	}
980 
981 	return count + moved;
982 }
983 
984 bool symbol__restricted_filename(const char *filename,
985 				 const char *restricted_filename)
986 {
987 	bool restricted = false;
988 
989 	if (symbol_conf.kptr_restrict) {
990 		char *r = realpath(filename, NULL);
991 
992 		if (r != NULL) {
993 			restricted = strcmp(r, restricted_filename) == 0;
994 			free(r);
995 			return restricted;
996 		}
997 	}
998 
999 	return restricted;
1000 }
1001 
1002 struct module_info {
1003 	struct rb_node rb_node;
1004 	char *name;
1005 	u64 start;
1006 };
1007 
1008 static void add_module(struct module_info *mi, struct rb_root *modules)
1009 {
1010 	struct rb_node **p = &modules->rb_node;
1011 	struct rb_node *parent = NULL;
1012 	struct module_info *m;
1013 
1014 	while (*p != NULL) {
1015 		parent = *p;
1016 		m = rb_entry(parent, struct module_info, rb_node);
1017 		if (strcmp(mi->name, m->name) < 0)
1018 			p = &(*p)->rb_left;
1019 		else
1020 			p = &(*p)->rb_right;
1021 	}
1022 	rb_link_node(&mi->rb_node, parent, p);
1023 	rb_insert_color(&mi->rb_node, modules);
1024 }
1025 
1026 static void delete_modules(struct rb_root *modules)
1027 {
1028 	struct module_info *mi;
1029 	struct rb_node *next = rb_first(modules);
1030 
1031 	while (next) {
1032 		mi = rb_entry(next, struct module_info, rb_node);
1033 		next = rb_next(&mi->rb_node);
1034 		rb_erase(&mi->rb_node, modules);
1035 		zfree(&mi->name);
1036 		free(mi);
1037 	}
1038 }
1039 
1040 static struct module_info *find_module(const char *name,
1041 				       struct rb_root *modules)
1042 {
1043 	struct rb_node *n = modules->rb_node;
1044 
1045 	while (n) {
1046 		struct module_info *m;
1047 		int cmp;
1048 
1049 		m = rb_entry(n, struct module_info, rb_node);
1050 		cmp = strcmp(name, m->name);
1051 		if (cmp < 0)
1052 			n = n->rb_left;
1053 		else if (cmp > 0)
1054 			n = n->rb_right;
1055 		else
1056 			return m;
1057 	}
1058 
1059 	return NULL;
1060 }
1061 
1062 static int __read_proc_modules(void *arg, const char *name, u64 start,
1063 			       u64 size __maybe_unused)
1064 {
1065 	struct rb_root *modules = arg;
1066 	struct module_info *mi;
1067 
1068 	mi = zalloc(sizeof(struct module_info));
1069 	if (!mi)
1070 		return -ENOMEM;
1071 
1072 	mi->name = strdup(name);
1073 	mi->start = start;
1074 
1075 	if (!mi->name) {
1076 		free(mi);
1077 		return -ENOMEM;
1078 	}
1079 
1080 	add_module(mi, modules);
1081 
1082 	return 0;
1083 }
1084 
1085 static int read_proc_modules(const char *filename, struct rb_root *modules)
1086 {
1087 	if (symbol__restricted_filename(filename, "/proc/modules"))
1088 		return -1;
1089 
1090 	if (modules__parse(filename, modules, __read_proc_modules)) {
1091 		delete_modules(modules);
1092 		return -1;
1093 	}
1094 
1095 	return 0;
1096 }
1097 
1098 int compare_proc_modules(const char *from, const char *to)
1099 {
1100 	struct rb_root from_modules = RB_ROOT;
1101 	struct rb_root to_modules = RB_ROOT;
1102 	struct rb_node *from_node, *to_node;
1103 	struct module_info *from_m, *to_m;
1104 	int ret = -1;
1105 
1106 	if (read_proc_modules(from, &from_modules))
1107 		return -1;
1108 
1109 	if (read_proc_modules(to, &to_modules))
1110 		goto out_delete_from;
1111 
1112 	from_node = rb_first(&from_modules);
1113 	to_node = rb_first(&to_modules);
1114 	while (from_node) {
1115 		if (!to_node)
1116 			break;
1117 
1118 		from_m = rb_entry(from_node, struct module_info, rb_node);
1119 		to_m = rb_entry(to_node, struct module_info, rb_node);
1120 
1121 		if (from_m->start != to_m->start ||
1122 		    strcmp(from_m->name, to_m->name))
1123 			break;
1124 
1125 		from_node = rb_next(from_node);
1126 		to_node = rb_next(to_node);
1127 	}
1128 
1129 	if (!from_node && !to_node)
1130 		ret = 0;
1131 
1132 	delete_modules(&to_modules);
1133 out_delete_from:
1134 	delete_modules(&from_modules);
1135 
1136 	return ret;
1137 }
1138 
1139 static int do_validate_kcore_modules(const char *filename, struct maps *kmaps)
1140 {
1141 	struct rb_root modules = RB_ROOT;
1142 	struct map_rb_node *old_node;
1143 	int err;
1144 
1145 	err = read_proc_modules(filename, &modules);
1146 	if (err)
1147 		return err;
1148 
1149 	maps__for_each_entry(kmaps, old_node) {
1150 		struct map *old_map = old_node->map;
1151 		struct module_info *mi;
1152 		struct dso *dso;
1153 
1154 		if (!__map__is_kmodule(old_map)) {
1155 			continue;
1156 		}
1157 		dso = map__dso(old_map);
1158 		/* Module must be in memory at the same address */
1159 		mi = find_module(dso->short_name, &modules);
1160 		if (!mi || mi->start != map__start(old_map)) {
1161 			err = -EINVAL;
1162 			goto out;
1163 		}
1164 	}
1165 out:
1166 	delete_modules(&modules);
1167 	return err;
1168 }
1169 
1170 /*
1171  * If kallsyms is referenced by name then we look for filename in the same
1172  * directory.
1173  */
1174 static bool filename_from_kallsyms_filename(char *filename,
1175 					    const char *base_name,
1176 					    const char *kallsyms_filename)
1177 {
1178 	char *name;
1179 
1180 	strcpy(filename, kallsyms_filename);
1181 	name = strrchr(filename, '/');
1182 	if (!name)
1183 		return false;
1184 
1185 	name += 1;
1186 
1187 	if (!strcmp(name, "kallsyms")) {
1188 		strcpy(name, base_name);
1189 		return true;
1190 	}
1191 
1192 	return false;
1193 }
1194 
1195 static int validate_kcore_modules(const char *kallsyms_filename,
1196 				  struct map *map)
1197 {
1198 	struct maps *kmaps = map__kmaps(map);
1199 	char modules_filename[PATH_MAX];
1200 
1201 	if (!kmaps)
1202 		return -EINVAL;
1203 
1204 	if (!filename_from_kallsyms_filename(modules_filename, "modules",
1205 					     kallsyms_filename))
1206 		return -EINVAL;
1207 
1208 	if (do_validate_kcore_modules(modules_filename, kmaps))
1209 		return -EINVAL;
1210 
1211 	return 0;
1212 }
1213 
1214 static int validate_kcore_addresses(const char *kallsyms_filename,
1215 				    struct map *map)
1216 {
1217 	struct kmap *kmap = map__kmap(map);
1218 
1219 	if (!kmap)
1220 		return -EINVAL;
1221 
1222 	if (kmap->ref_reloc_sym && kmap->ref_reloc_sym->name) {
1223 		u64 start;
1224 
1225 		if (kallsyms__get_function_start(kallsyms_filename,
1226 						 kmap->ref_reloc_sym->name, &start))
1227 			return -ENOENT;
1228 		if (start != kmap->ref_reloc_sym->addr)
1229 			return -EINVAL;
1230 	}
1231 
1232 	return validate_kcore_modules(kallsyms_filename, map);
1233 }
1234 
1235 struct kcore_mapfn_data {
1236 	struct dso *dso;
1237 	struct list_head maps;
1238 };
1239 
1240 static int kcore_mapfn(u64 start, u64 len, u64 pgoff, void *data)
1241 {
1242 	struct kcore_mapfn_data *md = data;
1243 	struct map_list_node *list_node = map_list_node__new();
1244 
1245 	if (!list_node)
1246 		return -ENOMEM;
1247 
1248 	list_node->map = map__new2(start, md->dso);
1249 	if (!list_node->map) {
1250 		free(list_node);
1251 		return -ENOMEM;
1252 	}
1253 
1254 	map__set_end(list_node->map, map__start(list_node->map) + len);
1255 	map__set_pgoff(list_node->map, pgoff);
1256 
1257 	list_add(&list_node->node, &md->maps);
1258 
1259 	return 0;
1260 }
1261 
1262 /*
1263  * Merges map into maps by splitting the new map within the existing map
1264  * regions.
1265  */
1266 int maps__merge_in(struct maps *kmaps, struct map *new_map)
1267 {
1268 	struct map_rb_node *rb_node;
1269 	LIST_HEAD(merged);
1270 	int err = 0;
1271 
1272 	maps__for_each_entry(kmaps, rb_node) {
1273 		struct map *old_map = rb_node->map;
1274 
1275 		/* no overload with this one */
1276 		if (map__end(new_map) < map__start(old_map) ||
1277 		    map__start(new_map) >= map__end(old_map))
1278 			continue;
1279 
1280 		if (map__start(new_map) < map__start(old_map)) {
1281 			/*
1282 			 * |new......
1283 			 *       |old....
1284 			 */
1285 			if (map__end(new_map) < map__end(old_map)) {
1286 				/*
1287 				 * |new......|     -> |new..|
1288 				 *       |old....| ->       |old....|
1289 				 */
1290 				map__set_end(new_map, map__start(old_map));
1291 			} else {
1292 				/*
1293 				 * |new.............| -> |new..|       |new..|
1294 				 *       |old....|    ->       |old....|
1295 				 */
1296 				struct map_list_node *m = map_list_node__new();
1297 
1298 				if (!m) {
1299 					err = -ENOMEM;
1300 					goto out;
1301 				}
1302 
1303 				m->map = map__clone(new_map);
1304 				if (!m->map) {
1305 					free(m);
1306 					err = -ENOMEM;
1307 					goto out;
1308 				}
1309 
1310 				map__set_end(m->map, map__start(old_map));
1311 				list_add_tail(&m->node, &merged);
1312 				map__add_pgoff(new_map, map__end(old_map) - map__start(new_map));
1313 				map__set_start(new_map, map__end(old_map));
1314 			}
1315 		} else {
1316 			/*
1317 			 *      |new......
1318 			 * |old....
1319 			 */
1320 			if (map__end(new_map) < map__end(old_map)) {
1321 				/*
1322 				 *      |new..|   -> x
1323 				 * |old.........| -> |old.........|
1324 				 */
1325 				map__put(new_map);
1326 				new_map = NULL;
1327 				break;
1328 			} else {
1329 				/*
1330 				 *      |new......| ->         |new...|
1331 				 * |old....|        -> |old....|
1332 				 */
1333 				map__add_pgoff(new_map, map__end(old_map) - map__start(new_map));
1334 				map__set_start(new_map, map__end(old_map));
1335 			}
1336 		}
1337 	}
1338 
1339 out:
1340 	while (!list_empty(&merged)) {
1341 		struct map_list_node *old_node;
1342 
1343 		old_node = list_entry(merged.next, struct map_list_node, node);
1344 		list_del_init(&old_node->node);
1345 		if (!err)
1346 			err = maps__insert(kmaps, old_node->map);
1347 		map__put(old_node->map);
1348 		free(old_node);
1349 	}
1350 
1351 	if (new_map) {
1352 		if (!err)
1353 			err = maps__insert(kmaps, new_map);
1354 		map__put(new_map);
1355 	}
1356 	return err;
1357 }
1358 
1359 static int dso__load_kcore(struct dso *dso, struct map *map,
1360 			   const char *kallsyms_filename)
1361 {
1362 	struct maps *kmaps = map__kmaps(map);
1363 	struct kcore_mapfn_data md;
1364 	struct map *replacement_map = NULL;
1365 	struct map_rb_node *old_node, *next;
1366 	struct machine *machine;
1367 	bool is_64_bit;
1368 	int err, fd;
1369 	char kcore_filename[PATH_MAX];
1370 	u64 stext;
1371 
1372 	if (!kmaps)
1373 		return -EINVAL;
1374 
1375 	machine = maps__machine(kmaps);
1376 
1377 	/* This function requires that the map is the kernel map */
1378 	if (!__map__is_kernel(map))
1379 		return -EINVAL;
1380 
1381 	if (!filename_from_kallsyms_filename(kcore_filename, "kcore",
1382 					     kallsyms_filename))
1383 		return -EINVAL;
1384 
1385 	/* Modules and kernel must be present at their original addresses */
1386 	if (validate_kcore_addresses(kallsyms_filename, map))
1387 		return -EINVAL;
1388 
1389 	md.dso = dso;
1390 	INIT_LIST_HEAD(&md.maps);
1391 
1392 	fd = open(kcore_filename, O_RDONLY);
1393 	if (fd < 0) {
1394 		pr_debug("Failed to open %s. Note /proc/kcore requires CAP_SYS_RAWIO capability to access.\n",
1395 			 kcore_filename);
1396 		return -EINVAL;
1397 	}
1398 
1399 	/* Read new maps into temporary lists */
1400 	err = file__read_maps(fd, map__prot(map) & PROT_EXEC, kcore_mapfn, &md,
1401 			      &is_64_bit);
1402 	if (err)
1403 		goto out_err;
1404 	dso->is_64_bit = is_64_bit;
1405 
1406 	if (list_empty(&md.maps)) {
1407 		err = -EINVAL;
1408 		goto out_err;
1409 	}
1410 
1411 	/* Remove old maps */
1412 	maps__for_each_entry_safe(kmaps, old_node, next) {
1413 		struct map *old_map = old_node->map;
1414 
1415 		/*
1416 		 * We need to preserve eBPF maps even if they are
1417 		 * covered by kcore, because we need to access
1418 		 * eBPF dso for source data.
1419 		 */
1420 		if (old_map != map && !__map__is_bpf_prog(old_map))
1421 			maps__remove(kmaps, old_map);
1422 	}
1423 	machine->trampolines_mapped = false;
1424 
1425 	/* Find the kernel map using the '_stext' symbol */
1426 	if (!kallsyms__get_function_start(kallsyms_filename, "_stext", &stext)) {
1427 		u64 replacement_size = 0;
1428 		struct map_list_node *new_node;
1429 
1430 		list_for_each_entry(new_node, &md.maps, node) {
1431 			struct map *new_map = new_node->map;
1432 			u64 new_size = map__size(new_map);
1433 
1434 			if (!(stext >= map__start(new_map) && stext < map__end(new_map)))
1435 				continue;
1436 
1437 			/*
1438 			 * On some architectures, ARM64 for example, the kernel
1439 			 * text can get allocated inside of the vmalloc segment.
1440 			 * Select the smallest matching segment, in case stext
1441 			 * falls within more than one in the list.
1442 			 */
1443 			if (!replacement_map || new_size < replacement_size) {
1444 				replacement_map = new_map;
1445 				replacement_size = new_size;
1446 			}
1447 		}
1448 	}
1449 
1450 	if (!replacement_map)
1451 		replacement_map = list_entry(md.maps.next, struct map_list_node, node)->map;
1452 
1453 	/* Add new maps */
1454 	while (!list_empty(&md.maps)) {
1455 		struct map_list_node *new_node = list_entry(md.maps.next, struct map_list_node, node);
1456 		struct map *new_map = new_node->map;
1457 
1458 		list_del_init(&new_node->node);
1459 
1460 		if (RC_CHK_ACCESS(new_map) == RC_CHK_ACCESS(replacement_map)) {
1461 			map__set_start(map, map__start(new_map));
1462 			map__set_end(map, map__end(new_map));
1463 			map__set_pgoff(map, map__pgoff(new_map));
1464 			map__set_map_ip(map, map__map_ip_ptr(new_map));
1465 			map__set_unmap_ip(map, map__unmap_ip_ptr(new_map));
1466 			/* Ensure maps are correctly ordered */
1467 			map__get(map);
1468 			maps__remove(kmaps, map);
1469 			err = maps__insert(kmaps, map);
1470 			map__put(map);
1471 			map__put(new_map);
1472 			if (err)
1473 				goto out_err;
1474 		} else {
1475 			/*
1476 			 * Merge kcore map into existing maps,
1477 			 * and ensure that current maps (eBPF)
1478 			 * stay intact.
1479 			 */
1480 			if (maps__merge_in(kmaps, new_map)) {
1481 				err = -EINVAL;
1482 				goto out_err;
1483 			}
1484 		}
1485 		free(new_node);
1486 	}
1487 
1488 	if (machine__is(machine, "x86_64")) {
1489 		u64 addr;
1490 
1491 		/*
1492 		 * If one of the corresponding symbols is there, assume the
1493 		 * entry trampoline maps are too.
1494 		 */
1495 		if (!kallsyms__get_function_start(kallsyms_filename,
1496 						  ENTRY_TRAMPOLINE_NAME,
1497 						  &addr))
1498 			machine->trampolines_mapped = true;
1499 	}
1500 
1501 	/*
1502 	 * Set the data type and long name so that kcore can be read via
1503 	 * dso__data_read_addr().
1504 	 */
1505 	if (dso->kernel == DSO_SPACE__KERNEL_GUEST)
1506 		dso->binary_type = DSO_BINARY_TYPE__GUEST_KCORE;
1507 	else
1508 		dso->binary_type = DSO_BINARY_TYPE__KCORE;
1509 	dso__set_long_name(dso, strdup(kcore_filename), true);
1510 
1511 	close(fd);
1512 
1513 	if (map__prot(map) & PROT_EXEC)
1514 		pr_debug("Using %s for kernel object code\n", kcore_filename);
1515 	else
1516 		pr_debug("Using %s for kernel data\n", kcore_filename);
1517 
1518 	return 0;
1519 
1520 out_err:
1521 	while (!list_empty(&md.maps)) {
1522 		struct map_list_node *list_node;
1523 
1524 		list_node = list_entry(md.maps.next, struct map_list_node, node);
1525 		list_del_init(&list_node->node);
1526 		map__zput(list_node->map);
1527 		free(list_node);
1528 	}
1529 	close(fd);
1530 	return err;
1531 }
1532 
1533 /*
1534  * If the kernel is relocated at boot time, kallsyms won't match.  Compute the
1535  * delta based on the relocation reference symbol.
1536  */
1537 static int kallsyms__delta(struct kmap *kmap, const char *filename, u64 *delta)
1538 {
1539 	u64 addr;
1540 
1541 	if (!kmap->ref_reloc_sym || !kmap->ref_reloc_sym->name)
1542 		return 0;
1543 
1544 	if (kallsyms__get_function_start(filename, kmap->ref_reloc_sym->name, &addr))
1545 		return -1;
1546 
1547 	*delta = addr - kmap->ref_reloc_sym->addr;
1548 	return 0;
1549 }
1550 
1551 int __dso__load_kallsyms(struct dso *dso, const char *filename,
1552 			 struct map *map, bool no_kcore)
1553 {
1554 	struct kmap *kmap = map__kmap(map);
1555 	u64 delta = 0;
1556 
1557 	if (symbol__restricted_filename(filename, "/proc/kallsyms"))
1558 		return -1;
1559 
1560 	if (!kmap || !kmap->kmaps)
1561 		return -1;
1562 
1563 	if (dso__load_all_kallsyms(dso, filename) < 0)
1564 		return -1;
1565 
1566 	if (kallsyms__delta(kmap, filename, &delta))
1567 		return -1;
1568 
1569 	symbols__fixup_end(&dso->symbols, true);
1570 	symbols__fixup_duplicate(&dso->symbols);
1571 
1572 	if (dso->kernel == DSO_SPACE__KERNEL_GUEST)
1573 		dso->symtab_type = DSO_BINARY_TYPE__GUEST_KALLSYMS;
1574 	else
1575 		dso->symtab_type = DSO_BINARY_TYPE__KALLSYMS;
1576 
1577 	if (!no_kcore && !dso__load_kcore(dso, map, filename))
1578 		return maps__split_kallsyms_for_kcore(kmap->kmaps, dso);
1579 	else
1580 		return maps__split_kallsyms(kmap->kmaps, dso, delta, map);
1581 }
1582 
1583 int dso__load_kallsyms(struct dso *dso, const char *filename,
1584 		       struct map *map)
1585 {
1586 	return __dso__load_kallsyms(dso, filename, map, false);
1587 }
1588 
1589 static int dso__load_perf_map(const char *map_path, struct dso *dso)
1590 {
1591 	char *line = NULL;
1592 	size_t n;
1593 	FILE *file;
1594 	int nr_syms = 0;
1595 
1596 	file = fopen(map_path, "r");
1597 	if (file == NULL)
1598 		goto out_failure;
1599 
1600 	while (!feof(file)) {
1601 		u64 start, size;
1602 		struct symbol *sym;
1603 		int line_len, len;
1604 
1605 		line_len = getline(&line, &n, file);
1606 		if (line_len < 0)
1607 			break;
1608 
1609 		if (!line)
1610 			goto out_failure;
1611 
1612 		line[--line_len] = '\0'; /* \n */
1613 
1614 		len = hex2u64(line, &start);
1615 
1616 		len++;
1617 		if (len + 2 >= line_len)
1618 			continue;
1619 
1620 		len += hex2u64(line + len, &size);
1621 
1622 		len++;
1623 		if (len + 2 >= line_len)
1624 			continue;
1625 
1626 		sym = symbol__new(start, size, STB_GLOBAL, STT_FUNC, line + len);
1627 
1628 		if (sym == NULL)
1629 			goto out_delete_line;
1630 
1631 		symbols__insert(&dso->symbols, sym);
1632 		nr_syms++;
1633 	}
1634 
1635 	free(line);
1636 	fclose(file);
1637 
1638 	return nr_syms;
1639 
1640 out_delete_line:
1641 	free(line);
1642 out_failure:
1643 	return -1;
1644 }
1645 
1646 #ifdef HAVE_LIBBFD_SUPPORT
1647 #define PACKAGE 'perf'
1648 #include <bfd.h>
1649 
1650 static int bfd_symbols__cmpvalue(const void *a, const void *b)
1651 {
1652 	const asymbol *as = *(const asymbol **)a, *bs = *(const asymbol **)b;
1653 
1654 	if (bfd_asymbol_value(as) != bfd_asymbol_value(bs))
1655 		return bfd_asymbol_value(as) - bfd_asymbol_value(bs);
1656 
1657 	return bfd_asymbol_name(as)[0] - bfd_asymbol_name(bs)[0];
1658 }
1659 
1660 static int bfd2elf_binding(asymbol *symbol)
1661 {
1662 	if (symbol->flags & BSF_WEAK)
1663 		return STB_WEAK;
1664 	if (symbol->flags & BSF_GLOBAL)
1665 		return STB_GLOBAL;
1666 	if (symbol->flags & BSF_LOCAL)
1667 		return STB_LOCAL;
1668 	return -1;
1669 }
1670 
1671 int dso__load_bfd_symbols(struct dso *dso, const char *debugfile)
1672 {
1673 	int err = -1;
1674 	long symbols_size, symbols_count, i;
1675 	asection *section;
1676 	asymbol **symbols, *sym;
1677 	struct symbol *symbol;
1678 	bfd *abfd;
1679 	u64 start, len;
1680 
1681 	abfd = bfd_openr(debugfile, NULL);
1682 	if (!abfd)
1683 		return -1;
1684 
1685 	if (!bfd_check_format(abfd, bfd_object)) {
1686 		pr_debug2("%s: cannot read %s bfd file.\n", __func__,
1687 			  dso->long_name);
1688 		goto out_close;
1689 	}
1690 
1691 	if (bfd_get_flavour(abfd) == bfd_target_elf_flavour)
1692 		goto out_close;
1693 
1694 	symbols_size = bfd_get_symtab_upper_bound(abfd);
1695 	if (symbols_size == 0) {
1696 		bfd_close(abfd);
1697 		return 0;
1698 	}
1699 
1700 	if (symbols_size < 0)
1701 		goto out_close;
1702 
1703 	symbols = malloc(symbols_size);
1704 	if (!symbols)
1705 		goto out_close;
1706 
1707 	symbols_count = bfd_canonicalize_symtab(abfd, symbols);
1708 	if (symbols_count < 0)
1709 		goto out_free;
1710 
1711 	section = bfd_get_section_by_name(abfd, ".text");
1712 	if (section) {
1713 		for (i = 0; i < symbols_count; ++i) {
1714 			if (!strcmp(bfd_asymbol_name(symbols[i]), "__ImageBase") ||
1715 			    !strcmp(bfd_asymbol_name(symbols[i]), "__image_base__"))
1716 				break;
1717 		}
1718 		if (i < symbols_count) {
1719 			/* PE symbols can only have 4 bytes, so use .text high bits */
1720 			dso->text_offset = section->vma - (u32)section->vma;
1721 			dso->text_offset += (u32)bfd_asymbol_value(symbols[i]);
1722 		} else {
1723 			dso->text_offset = section->vma - section->filepos;
1724 		}
1725 	}
1726 
1727 	qsort(symbols, symbols_count, sizeof(asymbol *), bfd_symbols__cmpvalue);
1728 
1729 #ifdef bfd_get_section
1730 #define bfd_asymbol_section bfd_get_section
1731 #endif
1732 	for (i = 0; i < symbols_count; ++i) {
1733 		sym = symbols[i];
1734 		section = bfd_asymbol_section(sym);
1735 		if (bfd2elf_binding(sym) < 0)
1736 			continue;
1737 
1738 		while (i + 1 < symbols_count &&
1739 		       bfd_asymbol_section(symbols[i + 1]) == section &&
1740 		       bfd2elf_binding(symbols[i + 1]) < 0)
1741 			i++;
1742 
1743 		if (i + 1 < symbols_count &&
1744 		    bfd_asymbol_section(symbols[i + 1]) == section)
1745 			len = symbols[i + 1]->value - sym->value;
1746 		else
1747 			len = section->size - sym->value;
1748 
1749 		start = bfd_asymbol_value(sym) - dso->text_offset;
1750 		symbol = symbol__new(start, len, bfd2elf_binding(sym), STT_FUNC,
1751 				     bfd_asymbol_name(sym));
1752 		if (!symbol)
1753 			goto out_free;
1754 
1755 		symbols__insert(&dso->symbols, symbol);
1756 	}
1757 #ifdef bfd_get_section
1758 #undef bfd_asymbol_section
1759 #endif
1760 
1761 	symbols__fixup_end(&dso->symbols, false);
1762 	symbols__fixup_duplicate(&dso->symbols);
1763 	dso->adjust_symbols = 1;
1764 
1765 	err = 0;
1766 out_free:
1767 	free(symbols);
1768 out_close:
1769 	bfd_close(abfd);
1770 	return err;
1771 }
1772 #endif
1773 
1774 static bool dso__is_compatible_symtab_type(struct dso *dso, bool kmod,
1775 					   enum dso_binary_type type)
1776 {
1777 	switch (type) {
1778 	case DSO_BINARY_TYPE__JAVA_JIT:
1779 	case DSO_BINARY_TYPE__DEBUGLINK:
1780 	case DSO_BINARY_TYPE__SYSTEM_PATH_DSO:
1781 	case DSO_BINARY_TYPE__FEDORA_DEBUGINFO:
1782 	case DSO_BINARY_TYPE__UBUNTU_DEBUGINFO:
1783 	case DSO_BINARY_TYPE__MIXEDUP_UBUNTU_DEBUGINFO:
1784 	case DSO_BINARY_TYPE__BUILDID_DEBUGINFO:
1785 	case DSO_BINARY_TYPE__OPENEMBEDDED_DEBUGINFO:
1786 		return !kmod && dso->kernel == DSO_SPACE__USER;
1787 
1788 	case DSO_BINARY_TYPE__KALLSYMS:
1789 	case DSO_BINARY_TYPE__VMLINUX:
1790 	case DSO_BINARY_TYPE__KCORE:
1791 		return dso->kernel == DSO_SPACE__KERNEL;
1792 
1793 	case DSO_BINARY_TYPE__GUEST_KALLSYMS:
1794 	case DSO_BINARY_TYPE__GUEST_VMLINUX:
1795 	case DSO_BINARY_TYPE__GUEST_KCORE:
1796 		return dso->kernel == DSO_SPACE__KERNEL_GUEST;
1797 
1798 	case DSO_BINARY_TYPE__GUEST_KMODULE:
1799 	case DSO_BINARY_TYPE__GUEST_KMODULE_COMP:
1800 	case DSO_BINARY_TYPE__SYSTEM_PATH_KMODULE:
1801 	case DSO_BINARY_TYPE__SYSTEM_PATH_KMODULE_COMP:
1802 		/*
1803 		 * kernel modules know their symtab type - it's set when
1804 		 * creating a module dso in machine__addnew_module_map().
1805 		 */
1806 		return kmod && dso->symtab_type == type;
1807 
1808 	case DSO_BINARY_TYPE__BUILD_ID_CACHE:
1809 	case DSO_BINARY_TYPE__BUILD_ID_CACHE_DEBUGINFO:
1810 		return true;
1811 
1812 	case DSO_BINARY_TYPE__BPF_PROG_INFO:
1813 	case DSO_BINARY_TYPE__BPF_IMAGE:
1814 	case DSO_BINARY_TYPE__OOL:
1815 	case DSO_BINARY_TYPE__NOT_FOUND:
1816 	default:
1817 		return false;
1818 	}
1819 }
1820 
1821 /* Checks for the existence of the perf-<pid>.map file in two different
1822  * locations.  First, if the process is a separate mount namespace, check in
1823  * that namespace using the pid of the innermost pid namespace.  If's not in a
1824  * namespace, or the file can't be found there, try in the mount namespace of
1825  * the tracing process using our view of its pid.
1826  */
1827 static int dso__find_perf_map(char *filebuf, size_t bufsz,
1828 			      struct nsinfo **nsip)
1829 {
1830 	struct nscookie nsc;
1831 	struct nsinfo *nsi;
1832 	struct nsinfo *nnsi;
1833 	int rc = -1;
1834 
1835 	nsi = *nsip;
1836 
1837 	if (nsinfo__need_setns(nsi)) {
1838 		snprintf(filebuf, bufsz, "/tmp/perf-%d.map", nsinfo__nstgid(nsi));
1839 		nsinfo__mountns_enter(nsi, &nsc);
1840 		rc = access(filebuf, R_OK);
1841 		nsinfo__mountns_exit(&nsc);
1842 		if (rc == 0)
1843 			return rc;
1844 	}
1845 
1846 	nnsi = nsinfo__copy(nsi);
1847 	if (nnsi) {
1848 		nsinfo__put(nsi);
1849 
1850 		nsinfo__clear_need_setns(nnsi);
1851 		snprintf(filebuf, bufsz, "/tmp/perf-%d.map", nsinfo__tgid(nnsi));
1852 		*nsip = nnsi;
1853 		rc = 0;
1854 	}
1855 
1856 	return rc;
1857 }
1858 
1859 int dso__load(struct dso *dso, struct map *map)
1860 {
1861 	char *name;
1862 	int ret = -1;
1863 	u_int i;
1864 	struct machine *machine = NULL;
1865 	char *root_dir = (char *) "";
1866 	int ss_pos = 0;
1867 	struct symsrc ss_[2];
1868 	struct symsrc *syms_ss = NULL, *runtime_ss = NULL;
1869 	bool kmod;
1870 	bool perfmap;
1871 	struct build_id bid;
1872 	struct nscookie nsc;
1873 	char newmapname[PATH_MAX];
1874 	const char *map_path = dso->long_name;
1875 
1876 	mutex_lock(&dso->lock);
1877 	perfmap = strncmp(dso->name, "/tmp/perf-", 10) == 0;
1878 	if (perfmap) {
1879 		if (dso->nsinfo && (dso__find_perf_map(newmapname,
1880 		    sizeof(newmapname), &dso->nsinfo) == 0)) {
1881 			map_path = newmapname;
1882 		}
1883 	}
1884 
1885 	nsinfo__mountns_enter(dso->nsinfo, &nsc);
1886 
1887 	/* check again under the dso->lock */
1888 	if (dso__loaded(dso)) {
1889 		ret = 1;
1890 		goto out;
1891 	}
1892 
1893 	kmod = dso->symtab_type == DSO_BINARY_TYPE__SYSTEM_PATH_KMODULE ||
1894 		dso->symtab_type == DSO_BINARY_TYPE__SYSTEM_PATH_KMODULE_COMP ||
1895 		dso->symtab_type == DSO_BINARY_TYPE__GUEST_KMODULE ||
1896 		dso->symtab_type == DSO_BINARY_TYPE__GUEST_KMODULE_COMP;
1897 
1898 	if (dso->kernel && !kmod) {
1899 		if (dso->kernel == DSO_SPACE__KERNEL)
1900 			ret = dso__load_kernel_sym(dso, map);
1901 		else if (dso->kernel == DSO_SPACE__KERNEL_GUEST)
1902 			ret = dso__load_guest_kernel_sym(dso, map);
1903 
1904 		machine = maps__machine(map__kmaps(map));
1905 		if (machine__is(machine, "x86_64"))
1906 			machine__map_x86_64_entry_trampolines(machine, dso);
1907 		goto out;
1908 	}
1909 
1910 	dso->adjust_symbols = 0;
1911 
1912 	if (perfmap) {
1913 		ret = dso__load_perf_map(map_path, dso);
1914 		dso->symtab_type = ret > 0 ? DSO_BINARY_TYPE__JAVA_JIT :
1915 					     DSO_BINARY_TYPE__NOT_FOUND;
1916 		goto out;
1917 	}
1918 
1919 	if (machine)
1920 		root_dir = machine->root_dir;
1921 
1922 	name = malloc(PATH_MAX);
1923 	if (!name)
1924 		goto out;
1925 
1926 	/*
1927 	 * Read the build id if possible. This is required for
1928 	 * DSO_BINARY_TYPE__BUILDID_DEBUGINFO to work
1929 	 */
1930 	if (!dso->has_build_id &&
1931 	    is_regular_file(dso->long_name)) {
1932 	    __symbol__join_symfs(name, PATH_MAX, dso->long_name);
1933 		if (filename__read_build_id(name, &bid) > 0)
1934 			dso__set_build_id(dso, &bid);
1935 	}
1936 
1937 	/*
1938 	 * Iterate over candidate debug images.
1939 	 * Keep track of "interesting" ones (those which have a symtab, dynsym,
1940 	 * and/or opd section) for processing.
1941 	 */
1942 	for (i = 0; i < DSO_BINARY_TYPE__SYMTAB_CNT; i++) {
1943 		struct symsrc *ss = &ss_[ss_pos];
1944 		bool next_slot = false;
1945 		bool is_reg;
1946 		bool nsexit;
1947 		int bfdrc = -1;
1948 		int sirc = -1;
1949 
1950 		enum dso_binary_type symtab_type = binary_type_symtab[i];
1951 
1952 		nsexit = (symtab_type == DSO_BINARY_TYPE__BUILD_ID_CACHE ||
1953 		    symtab_type == DSO_BINARY_TYPE__BUILD_ID_CACHE_DEBUGINFO);
1954 
1955 		if (!dso__is_compatible_symtab_type(dso, kmod, symtab_type))
1956 			continue;
1957 
1958 		if (dso__read_binary_type_filename(dso, symtab_type,
1959 						   root_dir, name, PATH_MAX))
1960 			continue;
1961 
1962 		if (nsexit)
1963 			nsinfo__mountns_exit(&nsc);
1964 
1965 		is_reg = is_regular_file(name);
1966 		if (!is_reg && errno == ENOENT && dso->nsinfo) {
1967 			char *new_name = dso__filename_with_chroot(dso, name);
1968 			if (new_name) {
1969 				is_reg = is_regular_file(new_name);
1970 				strlcpy(name, new_name, PATH_MAX);
1971 				free(new_name);
1972 			}
1973 		}
1974 
1975 #ifdef HAVE_LIBBFD_SUPPORT
1976 		if (is_reg)
1977 			bfdrc = dso__load_bfd_symbols(dso, name);
1978 #endif
1979 		if (is_reg && bfdrc < 0)
1980 			sirc = symsrc__init(ss, dso, name, symtab_type);
1981 
1982 		if (nsexit)
1983 			nsinfo__mountns_enter(dso->nsinfo, &nsc);
1984 
1985 		if (bfdrc == 0) {
1986 			ret = 0;
1987 			break;
1988 		}
1989 
1990 		if (!is_reg || sirc < 0)
1991 			continue;
1992 
1993 		if (!syms_ss && symsrc__has_symtab(ss)) {
1994 			syms_ss = ss;
1995 			next_slot = true;
1996 			if (!dso->symsrc_filename)
1997 				dso->symsrc_filename = strdup(name);
1998 		}
1999 
2000 		if (!runtime_ss && symsrc__possibly_runtime(ss)) {
2001 			runtime_ss = ss;
2002 			next_slot = true;
2003 		}
2004 
2005 		if (next_slot) {
2006 			ss_pos++;
2007 
2008 			if (syms_ss && runtime_ss)
2009 				break;
2010 		} else {
2011 			symsrc__destroy(ss);
2012 		}
2013 
2014 	}
2015 
2016 	if (!runtime_ss && !syms_ss)
2017 		goto out_free;
2018 
2019 	if (runtime_ss && !syms_ss) {
2020 		syms_ss = runtime_ss;
2021 	}
2022 
2023 	/* We'll have to hope for the best */
2024 	if (!runtime_ss && syms_ss)
2025 		runtime_ss = syms_ss;
2026 
2027 	if (syms_ss)
2028 		ret = dso__load_sym(dso, map, syms_ss, runtime_ss, kmod);
2029 	else
2030 		ret = -1;
2031 
2032 	if (ret > 0) {
2033 		int nr_plt;
2034 
2035 		nr_plt = dso__synthesize_plt_symbols(dso, runtime_ss);
2036 		if (nr_plt > 0)
2037 			ret += nr_plt;
2038 	}
2039 
2040 	for (; ss_pos > 0; ss_pos--)
2041 		symsrc__destroy(&ss_[ss_pos - 1]);
2042 out_free:
2043 	free(name);
2044 	if (ret < 0 && strstr(dso->name, " (deleted)") != NULL)
2045 		ret = 0;
2046 out:
2047 	dso__set_loaded(dso);
2048 	mutex_unlock(&dso->lock);
2049 	nsinfo__mountns_exit(&nsc);
2050 
2051 	return ret;
2052 }
2053 
2054 static int map__strcmp(const void *a, const void *b)
2055 {
2056 	const struct map *map_a = *(const struct map **)a;
2057 	const struct map *map_b = *(const struct map **)b;
2058 	const struct dso *dso_a = map__dso(map_a);
2059 	const struct dso *dso_b = map__dso(map_b);
2060 	int ret = strcmp(dso_a->short_name, dso_b->short_name);
2061 
2062 	if (ret == 0 && map_a != map_b) {
2063 		/*
2064 		 * Ensure distinct but name equal maps have an order in part to
2065 		 * aid reference counting.
2066 		 */
2067 		ret = (int)map__start(map_a) - (int)map__start(map_b);
2068 		if (ret == 0)
2069 			ret = (int)((intptr_t)map_a - (intptr_t)map_b);
2070 	}
2071 
2072 	return ret;
2073 }
2074 
2075 static int map__strcmp_name(const void *name, const void *b)
2076 {
2077 	const struct dso *dso = map__dso(*(const struct map **)b);
2078 
2079 	return strcmp(name, dso->short_name);
2080 }
2081 
2082 void __maps__sort_by_name(struct maps *maps)
2083 {
2084 	qsort(maps__maps_by_name(maps), maps__nr_maps(maps), sizeof(struct map *), map__strcmp);
2085 }
2086 
2087 static int map__groups__sort_by_name_from_rbtree(struct maps *maps)
2088 {
2089 	struct map_rb_node *rb_node;
2090 	struct map **maps_by_name = realloc(maps__maps_by_name(maps),
2091 					    maps__nr_maps(maps) * sizeof(struct map *));
2092 	int i = 0;
2093 
2094 	if (maps_by_name == NULL)
2095 		return -1;
2096 
2097 	up_read(maps__lock(maps));
2098 	down_write(maps__lock(maps));
2099 
2100 	RC_CHK_ACCESS(maps)->maps_by_name = maps_by_name;
2101 	RC_CHK_ACCESS(maps)->nr_maps_allocated = maps__nr_maps(maps);
2102 
2103 	maps__for_each_entry(maps, rb_node)
2104 		maps_by_name[i++] = map__get(rb_node->map);
2105 
2106 	__maps__sort_by_name(maps);
2107 
2108 	up_write(maps__lock(maps));
2109 	down_read(maps__lock(maps));
2110 
2111 	return 0;
2112 }
2113 
2114 static struct map *__maps__find_by_name(struct maps *maps, const char *name)
2115 {
2116 	struct map **mapp;
2117 
2118 	if (maps__maps_by_name(maps) == NULL &&
2119 	    map__groups__sort_by_name_from_rbtree(maps))
2120 		return NULL;
2121 
2122 	mapp = bsearch(name, maps__maps_by_name(maps), maps__nr_maps(maps),
2123 		       sizeof(*mapp), map__strcmp_name);
2124 	if (mapp)
2125 		return *mapp;
2126 	return NULL;
2127 }
2128 
2129 struct map *maps__find_by_name(struct maps *maps, const char *name)
2130 {
2131 	struct map_rb_node *rb_node;
2132 	struct map *map;
2133 
2134 	down_read(maps__lock(maps));
2135 
2136 
2137 	if (RC_CHK_ACCESS(maps)->last_search_by_name) {
2138 		const struct dso *dso = map__dso(RC_CHK_ACCESS(maps)->last_search_by_name);
2139 
2140 		if (strcmp(dso->short_name, name) == 0) {
2141 			map = RC_CHK_ACCESS(maps)->last_search_by_name;
2142 			goto out_unlock;
2143 		}
2144 	}
2145 	/*
2146 	 * If we have maps->maps_by_name, then the name isn't in the rbtree,
2147 	 * as maps->maps_by_name mirrors the rbtree when lookups by name are
2148 	 * made.
2149 	 */
2150 	map = __maps__find_by_name(maps, name);
2151 	if (map || maps__maps_by_name(maps) != NULL)
2152 		goto out_unlock;
2153 
2154 	/* Fallback to traversing the rbtree... */
2155 	maps__for_each_entry(maps, rb_node) {
2156 		struct dso *dso;
2157 
2158 		map = rb_node->map;
2159 		dso = map__dso(map);
2160 		if (strcmp(dso->short_name, name) == 0) {
2161 			RC_CHK_ACCESS(maps)->last_search_by_name = map;
2162 			goto out_unlock;
2163 		}
2164 	}
2165 	map = NULL;
2166 
2167 out_unlock:
2168 	up_read(maps__lock(maps));
2169 	return map;
2170 }
2171 
2172 int dso__load_vmlinux(struct dso *dso, struct map *map,
2173 		      const char *vmlinux, bool vmlinux_allocated)
2174 {
2175 	int err = -1;
2176 	struct symsrc ss;
2177 	char symfs_vmlinux[PATH_MAX];
2178 	enum dso_binary_type symtab_type;
2179 
2180 	if (vmlinux[0] == '/')
2181 		snprintf(symfs_vmlinux, sizeof(symfs_vmlinux), "%s", vmlinux);
2182 	else
2183 		symbol__join_symfs(symfs_vmlinux, vmlinux);
2184 
2185 	if (dso->kernel == DSO_SPACE__KERNEL_GUEST)
2186 		symtab_type = DSO_BINARY_TYPE__GUEST_VMLINUX;
2187 	else
2188 		symtab_type = DSO_BINARY_TYPE__VMLINUX;
2189 
2190 	if (symsrc__init(&ss, dso, symfs_vmlinux, symtab_type))
2191 		return -1;
2192 
2193 	err = dso__load_sym(dso, map, &ss, &ss, 0);
2194 	symsrc__destroy(&ss);
2195 
2196 	if (err > 0) {
2197 		if (dso->kernel == DSO_SPACE__KERNEL_GUEST)
2198 			dso->binary_type = DSO_BINARY_TYPE__GUEST_VMLINUX;
2199 		else
2200 			dso->binary_type = DSO_BINARY_TYPE__VMLINUX;
2201 		dso__set_long_name(dso, vmlinux, vmlinux_allocated);
2202 		dso__set_loaded(dso);
2203 		pr_debug("Using %s for symbols\n", symfs_vmlinux);
2204 	}
2205 
2206 	return err;
2207 }
2208 
2209 int dso__load_vmlinux_path(struct dso *dso, struct map *map)
2210 {
2211 	int i, err = 0;
2212 	char *filename = NULL;
2213 
2214 	pr_debug("Looking at the vmlinux_path (%d entries long)\n",
2215 		 vmlinux_path__nr_entries + 1);
2216 
2217 	for (i = 0; i < vmlinux_path__nr_entries; ++i) {
2218 		err = dso__load_vmlinux(dso, map, vmlinux_path[i], false);
2219 		if (err > 0)
2220 			goto out;
2221 	}
2222 
2223 	if (!symbol_conf.ignore_vmlinux_buildid)
2224 		filename = dso__build_id_filename(dso, NULL, 0, false);
2225 	if (filename != NULL) {
2226 		err = dso__load_vmlinux(dso, map, filename, true);
2227 		if (err > 0)
2228 			goto out;
2229 		free(filename);
2230 	}
2231 out:
2232 	return err;
2233 }
2234 
2235 static bool visible_dir_filter(const char *name, struct dirent *d)
2236 {
2237 	if (d->d_type != DT_DIR)
2238 		return false;
2239 	return lsdir_no_dot_filter(name, d);
2240 }
2241 
2242 static int find_matching_kcore(struct map *map, char *dir, size_t dir_sz)
2243 {
2244 	char kallsyms_filename[PATH_MAX];
2245 	int ret = -1;
2246 	struct strlist *dirs;
2247 	struct str_node *nd;
2248 
2249 	dirs = lsdir(dir, visible_dir_filter);
2250 	if (!dirs)
2251 		return -1;
2252 
2253 	strlist__for_each_entry(nd, dirs) {
2254 		scnprintf(kallsyms_filename, sizeof(kallsyms_filename),
2255 			  "%s/%s/kallsyms", dir, nd->s);
2256 		if (!validate_kcore_addresses(kallsyms_filename, map)) {
2257 			strlcpy(dir, kallsyms_filename, dir_sz);
2258 			ret = 0;
2259 			break;
2260 		}
2261 	}
2262 
2263 	strlist__delete(dirs);
2264 
2265 	return ret;
2266 }
2267 
2268 /*
2269  * Use open(O_RDONLY) to check readability directly instead of access(R_OK)
2270  * since access(R_OK) only checks with real UID/GID but open() use effective
2271  * UID/GID and actual capabilities (e.g. /proc/kcore requires CAP_SYS_RAWIO).
2272  */
2273 static bool filename__readable(const char *file)
2274 {
2275 	int fd = open(file, O_RDONLY);
2276 	if (fd < 0)
2277 		return false;
2278 	close(fd);
2279 	return true;
2280 }
2281 
2282 static char *dso__find_kallsyms(struct dso *dso, struct map *map)
2283 {
2284 	struct build_id bid;
2285 	char sbuild_id[SBUILD_ID_SIZE];
2286 	bool is_host = false;
2287 	char path[PATH_MAX];
2288 
2289 	if (!dso->has_build_id) {
2290 		/*
2291 		 * Last resort, if we don't have a build-id and couldn't find
2292 		 * any vmlinux file, try the running kernel kallsyms table.
2293 		 */
2294 		goto proc_kallsyms;
2295 	}
2296 
2297 	if (sysfs__read_build_id("/sys/kernel/notes", &bid) == 0)
2298 		is_host = dso__build_id_equal(dso, &bid);
2299 
2300 	/* Try a fast path for /proc/kallsyms if possible */
2301 	if (is_host) {
2302 		/*
2303 		 * Do not check the build-id cache, unless we know we cannot use
2304 		 * /proc/kcore or module maps don't match to /proc/kallsyms.
2305 		 * To check readability of /proc/kcore, do not use access(R_OK)
2306 		 * since /proc/kcore requires CAP_SYS_RAWIO to read and access
2307 		 * can't check it.
2308 		 */
2309 		if (filename__readable("/proc/kcore") &&
2310 		    !validate_kcore_addresses("/proc/kallsyms", map))
2311 			goto proc_kallsyms;
2312 	}
2313 
2314 	build_id__sprintf(&dso->bid, sbuild_id);
2315 
2316 	/* Find kallsyms in build-id cache with kcore */
2317 	scnprintf(path, sizeof(path), "%s/%s/%s",
2318 		  buildid_dir, DSO__NAME_KCORE, sbuild_id);
2319 
2320 	if (!find_matching_kcore(map, path, sizeof(path)))
2321 		return strdup(path);
2322 
2323 	/* Use current /proc/kallsyms if possible */
2324 	if (is_host) {
2325 proc_kallsyms:
2326 		return strdup("/proc/kallsyms");
2327 	}
2328 
2329 	/* Finally, find a cache of kallsyms */
2330 	if (!build_id_cache__kallsyms_path(sbuild_id, path, sizeof(path))) {
2331 		pr_err("No kallsyms or vmlinux with build-id %s was found\n",
2332 		       sbuild_id);
2333 		return NULL;
2334 	}
2335 
2336 	return strdup(path);
2337 }
2338 
2339 static int dso__load_kernel_sym(struct dso *dso, struct map *map)
2340 {
2341 	int err;
2342 	const char *kallsyms_filename = NULL;
2343 	char *kallsyms_allocated_filename = NULL;
2344 	char *filename = NULL;
2345 
2346 	/*
2347 	 * Step 1: if the user specified a kallsyms or vmlinux filename, use
2348 	 * it and only it, reporting errors to the user if it cannot be used.
2349 	 *
2350 	 * For instance, try to analyse an ARM perf.data file _without_ a
2351 	 * build-id, or if the user specifies the wrong path to the right
2352 	 * vmlinux file, obviously we can't fallback to another vmlinux (a
2353 	 * x86_86 one, on the machine where analysis is being performed, say),
2354 	 * or worse, /proc/kallsyms.
2355 	 *
2356 	 * If the specified file _has_ a build-id and there is a build-id
2357 	 * section in the perf.data file, we will still do the expected
2358 	 * validation in dso__load_vmlinux and will bail out if they don't
2359 	 * match.
2360 	 */
2361 	if (symbol_conf.kallsyms_name != NULL) {
2362 		kallsyms_filename = symbol_conf.kallsyms_name;
2363 		goto do_kallsyms;
2364 	}
2365 
2366 	if (!symbol_conf.ignore_vmlinux && symbol_conf.vmlinux_name != NULL) {
2367 		return dso__load_vmlinux(dso, map, symbol_conf.vmlinux_name, false);
2368 	}
2369 
2370 	/*
2371 	 * Before checking on common vmlinux locations, check if it's
2372 	 * stored as standard build id binary (not kallsyms) under
2373 	 * .debug cache.
2374 	 */
2375 	if (!symbol_conf.ignore_vmlinux_buildid)
2376 		filename = __dso__build_id_filename(dso, NULL, 0, false, false);
2377 	if (filename != NULL) {
2378 		err = dso__load_vmlinux(dso, map, filename, true);
2379 		if (err > 0)
2380 			return err;
2381 		free(filename);
2382 	}
2383 
2384 	if (!symbol_conf.ignore_vmlinux && vmlinux_path != NULL) {
2385 		err = dso__load_vmlinux_path(dso, map);
2386 		if (err > 0)
2387 			return err;
2388 	}
2389 
2390 	/* do not try local files if a symfs was given */
2391 	if (symbol_conf.symfs[0] != 0)
2392 		return -1;
2393 
2394 	kallsyms_allocated_filename = dso__find_kallsyms(dso, map);
2395 	if (!kallsyms_allocated_filename)
2396 		return -1;
2397 
2398 	kallsyms_filename = kallsyms_allocated_filename;
2399 
2400 do_kallsyms:
2401 	err = dso__load_kallsyms(dso, kallsyms_filename, map);
2402 	if (err > 0)
2403 		pr_debug("Using %s for symbols\n", kallsyms_filename);
2404 	free(kallsyms_allocated_filename);
2405 
2406 	if (err > 0 && !dso__is_kcore(dso)) {
2407 		dso->binary_type = DSO_BINARY_TYPE__KALLSYMS;
2408 		dso__set_long_name(dso, DSO__NAME_KALLSYMS, false);
2409 		map__fixup_start(map);
2410 		map__fixup_end(map);
2411 	}
2412 
2413 	return err;
2414 }
2415 
2416 static int dso__load_guest_kernel_sym(struct dso *dso, struct map *map)
2417 {
2418 	int err;
2419 	const char *kallsyms_filename;
2420 	struct machine *machine = maps__machine(map__kmaps(map));
2421 	char path[PATH_MAX];
2422 
2423 	if (machine->kallsyms_filename) {
2424 		kallsyms_filename = machine->kallsyms_filename;
2425 	} else if (machine__is_default_guest(machine)) {
2426 		/*
2427 		 * if the user specified a vmlinux filename, use it and only
2428 		 * it, reporting errors to the user if it cannot be used.
2429 		 * Or use file guest_kallsyms inputted by user on commandline
2430 		 */
2431 		if (symbol_conf.default_guest_vmlinux_name != NULL) {
2432 			err = dso__load_vmlinux(dso, map,
2433 						symbol_conf.default_guest_vmlinux_name,
2434 						false);
2435 			return err;
2436 		}
2437 
2438 		kallsyms_filename = symbol_conf.default_guest_kallsyms;
2439 		if (!kallsyms_filename)
2440 			return -1;
2441 	} else {
2442 		sprintf(path, "%s/proc/kallsyms", machine->root_dir);
2443 		kallsyms_filename = path;
2444 	}
2445 
2446 	err = dso__load_kallsyms(dso, kallsyms_filename, map);
2447 	if (err > 0)
2448 		pr_debug("Using %s for symbols\n", kallsyms_filename);
2449 	if (err > 0 && !dso__is_kcore(dso)) {
2450 		dso->binary_type = DSO_BINARY_TYPE__GUEST_KALLSYMS;
2451 		dso__set_long_name(dso, machine->mmap_name, false);
2452 		map__fixup_start(map);
2453 		map__fixup_end(map);
2454 	}
2455 
2456 	return err;
2457 }
2458 
2459 static void vmlinux_path__exit(void)
2460 {
2461 	while (--vmlinux_path__nr_entries >= 0)
2462 		zfree(&vmlinux_path[vmlinux_path__nr_entries]);
2463 	vmlinux_path__nr_entries = 0;
2464 
2465 	zfree(&vmlinux_path);
2466 }
2467 
2468 static const char * const vmlinux_paths[] = {
2469 	"vmlinux",
2470 	"/boot/vmlinux"
2471 };
2472 
2473 static const char * const vmlinux_paths_upd[] = {
2474 	"/boot/vmlinux-%s",
2475 	"/usr/lib/debug/boot/vmlinux-%s",
2476 	"/lib/modules/%s/build/vmlinux",
2477 	"/usr/lib/debug/lib/modules/%s/vmlinux",
2478 	"/usr/lib/debug/boot/vmlinux-%s.debug"
2479 };
2480 
2481 static int vmlinux_path__add(const char *new_entry)
2482 {
2483 	vmlinux_path[vmlinux_path__nr_entries] = strdup(new_entry);
2484 	if (vmlinux_path[vmlinux_path__nr_entries] == NULL)
2485 		return -1;
2486 	++vmlinux_path__nr_entries;
2487 
2488 	return 0;
2489 }
2490 
2491 static int vmlinux_path__init(struct perf_env *env)
2492 {
2493 	struct utsname uts;
2494 	char bf[PATH_MAX];
2495 	char *kernel_version;
2496 	unsigned int i;
2497 
2498 	vmlinux_path = malloc(sizeof(char *) * (ARRAY_SIZE(vmlinux_paths) +
2499 			      ARRAY_SIZE(vmlinux_paths_upd)));
2500 	if (vmlinux_path == NULL)
2501 		return -1;
2502 
2503 	for (i = 0; i < ARRAY_SIZE(vmlinux_paths); i++)
2504 		if (vmlinux_path__add(vmlinux_paths[i]) < 0)
2505 			goto out_fail;
2506 
2507 	/* only try kernel version if no symfs was given */
2508 	if (symbol_conf.symfs[0] != 0)
2509 		return 0;
2510 
2511 	if (env) {
2512 		kernel_version = env->os_release;
2513 	} else {
2514 		if (uname(&uts) < 0)
2515 			goto out_fail;
2516 
2517 		kernel_version = uts.release;
2518 	}
2519 
2520 	for (i = 0; i < ARRAY_SIZE(vmlinux_paths_upd); i++) {
2521 		snprintf(bf, sizeof(bf), vmlinux_paths_upd[i], kernel_version);
2522 		if (vmlinux_path__add(bf) < 0)
2523 			goto out_fail;
2524 	}
2525 
2526 	return 0;
2527 
2528 out_fail:
2529 	vmlinux_path__exit();
2530 	return -1;
2531 }
2532 
2533 int setup_list(struct strlist **list, const char *list_str,
2534 		      const char *list_name)
2535 {
2536 	if (list_str == NULL)
2537 		return 0;
2538 
2539 	*list = strlist__new(list_str, NULL);
2540 	if (!*list) {
2541 		pr_err("problems parsing %s list\n", list_name);
2542 		return -1;
2543 	}
2544 
2545 	symbol_conf.has_filter = true;
2546 	return 0;
2547 }
2548 
2549 int setup_intlist(struct intlist **list, const char *list_str,
2550 		  const char *list_name)
2551 {
2552 	if (list_str == NULL)
2553 		return 0;
2554 
2555 	*list = intlist__new(list_str);
2556 	if (!*list) {
2557 		pr_err("problems parsing %s list\n", list_name);
2558 		return -1;
2559 	}
2560 	return 0;
2561 }
2562 
2563 static int setup_addrlist(struct intlist **addr_list, struct strlist *sym_list)
2564 {
2565 	struct str_node *pos, *tmp;
2566 	unsigned long val;
2567 	char *sep;
2568 	const char *end;
2569 	int i = 0, err;
2570 
2571 	*addr_list = intlist__new(NULL);
2572 	if (!*addr_list)
2573 		return -1;
2574 
2575 	strlist__for_each_entry_safe(pos, tmp, sym_list) {
2576 		errno = 0;
2577 		val = strtoul(pos->s, &sep, 16);
2578 		if (errno || (sep == pos->s))
2579 			continue;
2580 
2581 		if (*sep != '\0') {
2582 			end = pos->s + strlen(pos->s) - 1;
2583 			while (end >= sep && isspace(*end))
2584 				end--;
2585 
2586 			if (end >= sep)
2587 				continue;
2588 		}
2589 
2590 		err = intlist__add(*addr_list, val);
2591 		if (err)
2592 			break;
2593 
2594 		strlist__remove(sym_list, pos);
2595 		i++;
2596 	}
2597 
2598 	if (i == 0) {
2599 		intlist__delete(*addr_list);
2600 		*addr_list = NULL;
2601 	}
2602 
2603 	return 0;
2604 }
2605 
2606 static bool symbol__read_kptr_restrict(void)
2607 {
2608 	bool value = false;
2609 	FILE *fp = fopen("/proc/sys/kernel/kptr_restrict", "r");
2610 
2611 	if (fp != NULL) {
2612 		char line[8];
2613 
2614 		if (fgets(line, sizeof(line), fp) != NULL)
2615 			value = perf_cap__capable(CAP_SYSLOG) ?
2616 					(atoi(line) >= 2) :
2617 					(atoi(line) != 0);
2618 
2619 		fclose(fp);
2620 	}
2621 
2622 	/* Per kernel/kallsyms.c:
2623 	 * we also restrict when perf_event_paranoid > 1 w/o CAP_SYSLOG
2624 	 */
2625 	if (perf_event_paranoid() > 1 && !perf_cap__capable(CAP_SYSLOG))
2626 		value = true;
2627 
2628 	return value;
2629 }
2630 
2631 int symbol__annotation_init(void)
2632 {
2633 	if (symbol_conf.init_annotation)
2634 		return 0;
2635 
2636 	if (symbol_conf.initialized) {
2637 		pr_err("Annotation needs to be init before symbol__init()\n");
2638 		return -1;
2639 	}
2640 
2641 	symbol_conf.priv_size += sizeof(struct annotation);
2642 	symbol_conf.init_annotation = true;
2643 	return 0;
2644 }
2645 
2646 int symbol__init(struct perf_env *env)
2647 {
2648 	const char *symfs;
2649 
2650 	if (symbol_conf.initialized)
2651 		return 0;
2652 
2653 	symbol_conf.priv_size = PERF_ALIGN(symbol_conf.priv_size, sizeof(u64));
2654 
2655 	symbol__elf_init();
2656 
2657 	if (symbol_conf.sort_by_name)
2658 		symbol_conf.priv_size += (sizeof(struct symbol_name_rb_node) -
2659 					  sizeof(struct symbol));
2660 
2661 	if (symbol_conf.try_vmlinux_path && vmlinux_path__init(env) < 0)
2662 		return -1;
2663 
2664 	if (symbol_conf.field_sep && *symbol_conf.field_sep == '.') {
2665 		pr_err("'.' is the only non valid --field-separator argument\n");
2666 		return -1;
2667 	}
2668 
2669 	if (setup_list(&symbol_conf.dso_list,
2670 		       symbol_conf.dso_list_str, "dso") < 0)
2671 		return -1;
2672 
2673 	if (setup_list(&symbol_conf.comm_list,
2674 		       symbol_conf.comm_list_str, "comm") < 0)
2675 		goto out_free_dso_list;
2676 
2677 	if (setup_intlist(&symbol_conf.pid_list,
2678 		       symbol_conf.pid_list_str, "pid") < 0)
2679 		goto out_free_comm_list;
2680 
2681 	if (setup_intlist(&symbol_conf.tid_list,
2682 		       symbol_conf.tid_list_str, "tid") < 0)
2683 		goto out_free_pid_list;
2684 
2685 	if (setup_list(&symbol_conf.sym_list,
2686 		       symbol_conf.sym_list_str, "symbol") < 0)
2687 		goto out_free_tid_list;
2688 
2689 	if (symbol_conf.sym_list &&
2690 	    setup_addrlist(&symbol_conf.addr_list, symbol_conf.sym_list) < 0)
2691 		goto out_free_sym_list;
2692 
2693 	if (setup_list(&symbol_conf.bt_stop_list,
2694 		       symbol_conf.bt_stop_list_str, "symbol") < 0)
2695 		goto out_free_sym_list;
2696 
2697 	/*
2698 	 * A path to symbols of "/" is identical to ""
2699 	 * reset here for simplicity.
2700 	 */
2701 	symfs = realpath(symbol_conf.symfs, NULL);
2702 	if (symfs == NULL)
2703 		symfs = symbol_conf.symfs;
2704 	if (strcmp(symfs, "/") == 0)
2705 		symbol_conf.symfs = "";
2706 	if (symfs != symbol_conf.symfs)
2707 		free((void *)symfs);
2708 
2709 	symbol_conf.kptr_restrict = symbol__read_kptr_restrict();
2710 
2711 	symbol_conf.initialized = true;
2712 	return 0;
2713 
2714 out_free_sym_list:
2715 	strlist__delete(symbol_conf.sym_list);
2716 	intlist__delete(symbol_conf.addr_list);
2717 out_free_tid_list:
2718 	intlist__delete(symbol_conf.tid_list);
2719 out_free_pid_list:
2720 	intlist__delete(symbol_conf.pid_list);
2721 out_free_comm_list:
2722 	strlist__delete(symbol_conf.comm_list);
2723 out_free_dso_list:
2724 	strlist__delete(symbol_conf.dso_list);
2725 	return -1;
2726 }
2727 
2728 void symbol__exit(void)
2729 {
2730 	if (!symbol_conf.initialized)
2731 		return;
2732 	strlist__delete(symbol_conf.bt_stop_list);
2733 	strlist__delete(symbol_conf.sym_list);
2734 	strlist__delete(symbol_conf.dso_list);
2735 	strlist__delete(symbol_conf.comm_list);
2736 	intlist__delete(symbol_conf.tid_list);
2737 	intlist__delete(symbol_conf.pid_list);
2738 	intlist__delete(symbol_conf.addr_list);
2739 	vmlinux_path__exit();
2740 	symbol_conf.sym_list = symbol_conf.dso_list = symbol_conf.comm_list = NULL;
2741 	symbol_conf.bt_stop_list = NULL;
2742 	symbol_conf.initialized = false;
2743 }
2744 
2745 int symbol__config_symfs(const struct option *opt __maybe_unused,
2746 			 const char *dir, int unset __maybe_unused)
2747 {
2748 	char *bf = NULL;
2749 	int ret;
2750 
2751 	symbol_conf.symfs = strdup(dir);
2752 	if (symbol_conf.symfs == NULL)
2753 		return -ENOMEM;
2754 
2755 	/* skip the locally configured cache if a symfs is given, and
2756 	 * config buildid dir to symfs/.debug
2757 	 */
2758 	ret = asprintf(&bf, "%s/%s", dir, ".debug");
2759 	if (ret < 0)
2760 		return -ENOMEM;
2761 
2762 	set_buildid_dir(bf);
2763 
2764 	free(bf);
2765 	return 0;
2766 }
2767 
2768 struct mem_info *mem_info__get(struct mem_info *mi)
2769 {
2770 	if (mi)
2771 		refcount_inc(&mi->refcnt);
2772 	return mi;
2773 }
2774 
2775 void mem_info__put(struct mem_info *mi)
2776 {
2777 	if (mi && refcount_dec_and_test(&mi->refcnt))
2778 		free(mi);
2779 }
2780 
2781 struct mem_info *mem_info__new(void)
2782 {
2783 	struct mem_info *mi = zalloc(sizeof(*mi));
2784 
2785 	if (mi)
2786 		refcount_set(&mi->refcnt, 1);
2787 	return mi;
2788 }
2789 
2790 /*
2791  * Checks that user supplied symbol kernel files are accessible because
2792  * the default mechanism for accessing elf files fails silently. i.e. if
2793  * debug syms for a build ID aren't found perf carries on normally. When
2794  * they are user supplied we should assume that the user doesn't want to
2795  * silently fail.
2796  */
2797 int symbol__validate_sym_arguments(void)
2798 {
2799 	if (symbol_conf.vmlinux_name &&
2800 	    access(symbol_conf.vmlinux_name, R_OK)) {
2801 		pr_err("Invalid file: %s\n", symbol_conf.vmlinux_name);
2802 		return -EINVAL;
2803 	}
2804 	if (symbol_conf.kallsyms_name &&
2805 	    access(symbol_conf.kallsyms_name, R_OK)) {
2806 		pr_err("Invalid file: %s\n", symbol_conf.kallsyms_name);
2807 		return -EINVAL;
2808 	}
2809 	return 0;
2810 }
2811