1 // SPDX-License-Identifier: GPL-2.0
2 #include <dirent.h>
3 #include <errno.h>
4 #include <stdlib.h>
5 #include <stdio.h>
6 #include <string.h>
7 #include <linux/capability.h>
8 #include <linux/kernel.h>
9 #include <linux/mman.h>
10 #include <linux/string.h>
11 #include <linux/time64.h>
12 #include <sys/types.h>
13 #include <sys/stat.h>
14 #include <sys/param.h>
15 #include <fcntl.h>
16 #include <unistd.h>
17 #include <inttypes.h>
18 #include "annotate.h"
19 #include "build-id.h"
20 #include "cap.h"
21 #include "dso.h"
22 #include "util.h" // lsdir()
23 #include "debug.h"
24 #include "event.h"
25 #include "machine.h"
26 #include "map.h"
27 #include "symbol.h"
28 #include "map_symbol.h"
29 #include "mem-events.h"
30 #include "symsrc.h"
31 #include "strlist.h"
32 #include "intlist.h"
33 #include "namespaces.h"
34 #include "header.h"
35 #include "path.h"
36 #include <linux/ctype.h>
37 #include <linux/zalloc.h>
38 
39 #include <elf.h>
40 #include <limits.h>
41 #include <symbol/kallsyms.h>
42 #include <sys/utsname.h>
43 
44 static int dso__load_kernel_sym(struct dso *dso, struct map *map);
45 static int dso__load_guest_kernel_sym(struct dso *dso, struct map *map);
46 static bool symbol__is_idle(const char *name);
47 
48 int vmlinux_path__nr_entries;
49 char **vmlinux_path;
50 
51 struct symbol_conf symbol_conf = {
52 	.nanosecs		= false,
53 	.use_modules		= true,
54 	.try_vmlinux_path	= true,
55 	.demangle		= true,
56 	.demangle_kernel	= false,
57 	.cumulate_callchain	= true,
58 	.time_quantum		= 100 * NSEC_PER_MSEC, /* 100ms */
59 	.show_hist_headers	= true,
60 	.symfs			= "",
61 	.event_group		= true,
62 	.inline_name		= true,
63 	.res_sample		= 0,
64 };
65 
66 static enum dso_binary_type binary_type_symtab[] = {
67 	DSO_BINARY_TYPE__KALLSYMS,
68 	DSO_BINARY_TYPE__GUEST_KALLSYMS,
69 	DSO_BINARY_TYPE__JAVA_JIT,
70 	DSO_BINARY_TYPE__DEBUGLINK,
71 	DSO_BINARY_TYPE__BUILD_ID_CACHE,
72 	DSO_BINARY_TYPE__BUILD_ID_CACHE_DEBUGINFO,
73 	DSO_BINARY_TYPE__FEDORA_DEBUGINFO,
74 	DSO_BINARY_TYPE__UBUNTU_DEBUGINFO,
75 	DSO_BINARY_TYPE__BUILDID_DEBUGINFO,
76 	DSO_BINARY_TYPE__SYSTEM_PATH_DSO,
77 	DSO_BINARY_TYPE__GUEST_KMODULE,
78 	DSO_BINARY_TYPE__GUEST_KMODULE_COMP,
79 	DSO_BINARY_TYPE__SYSTEM_PATH_KMODULE,
80 	DSO_BINARY_TYPE__SYSTEM_PATH_KMODULE_COMP,
81 	DSO_BINARY_TYPE__OPENEMBEDDED_DEBUGINFO,
82 	DSO_BINARY_TYPE__MIXEDUP_UBUNTU_DEBUGINFO,
83 	DSO_BINARY_TYPE__NOT_FOUND,
84 };
85 
86 #define DSO_BINARY_TYPE__SYMTAB_CNT ARRAY_SIZE(binary_type_symtab)
87 
symbol_type__filter(char symbol_type)88 static bool symbol_type__filter(char symbol_type)
89 {
90 	symbol_type = toupper(symbol_type);
91 	return symbol_type == 'T' || symbol_type == 'W' || symbol_type == 'D' || symbol_type == 'B';
92 }
93 
prefix_underscores_count(const char * str)94 static int prefix_underscores_count(const char *str)
95 {
96 	const char *tail = str;
97 
98 	while (*tail == '_')
99 		tail++;
100 
101 	return tail - str;
102 }
103 
arch__normalize_symbol_name(const char * name)104 const char * __weak arch__normalize_symbol_name(const char *name)
105 {
106 	return name;
107 }
108 
arch__compare_symbol_names(const char * namea,const char * nameb)109 int __weak arch__compare_symbol_names(const char *namea, const char *nameb)
110 {
111 	return strcmp(namea, nameb);
112 }
113 
arch__compare_symbol_names_n(const char * namea,const char * nameb,unsigned int n)114 int __weak arch__compare_symbol_names_n(const char *namea, const char *nameb,
115 					unsigned int n)
116 {
117 	return strncmp(namea, nameb, n);
118 }
119 
arch__choose_best_symbol(struct symbol * syma,struct symbol * symb __maybe_unused)120 int __weak arch__choose_best_symbol(struct symbol *syma,
121 				    struct symbol *symb __maybe_unused)
122 {
123 	/* Avoid "SyS" kernel syscall aliases */
124 	if (strlen(syma->name) >= 3 && !strncmp(syma->name, "SyS", 3))
125 		return SYMBOL_B;
126 	if (strlen(syma->name) >= 10 && !strncmp(syma->name, "compat_SyS", 10))
127 		return SYMBOL_B;
128 
129 	return SYMBOL_A;
130 }
131 
choose_best_symbol(struct symbol * syma,struct symbol * symb)132 static int choose_best_symbol(struct symbol *syma, struct symbol *symb)
133 {
134 	s64 a;
135 	s64 b;
136 	size_t na, nb;
137 
138 	/* Prefer a symbol with non zero length */
139 	a = syma->end - syma->start;
140 	b = symb->end - symb->start;
141 	if ((b == 0) && (a > 0))
142 		return SYMBOL_A;
143 	else if ((a == 0) && (b > 0))
144 		return SYMBOL_B;
145 
146 	/* Prefer a non weak symbol over a weak one */
147 	a = syma->binding == STB_WEAK;
148 	b = symb->binding == STB_WEAK;
149 	if (b && !a)
150 		return SYMBOL_A;
151 	if (a && !b)
152 		return SYMBOL_B;
153 
154 	/* Prefer a global symbol over a non global one */
155 	a = syma->binding == STB_GLOBAL;
156 	b = symb->binding == STB_GLOBAL;
157 	if (a && !b)
158 		return SYMBOL_A;
159 	if (b && !a)
160 		return SYMBOL_B;
161 
162 	/* Prefer a symbol with less underscores */
163 	a = prefix_underscores_count(syma->name);
164 	b = prefix_underscores_count(symb->name);
165 	if (b > a)
166 		return SYMBOL_A;
167 	else if (a > b)
168 		return SYMBOL_B;
169 
170 	/* Choose the symbol with the longest name */
171 	na = strlen(syma->name);
172 	nb = strlen(symb->name);
173 	if (na > nb)
174 		return SYMBOL_A;
175 	else if (na < nb)
176 		return SYMBOL_B;
177 
178 	return arch__choose_best_symbol(syma, symb);
179 }
180 
symbols__fixup_duplicate(struct rb_root_cached * symbols)181 void symbols__fixup_duplicate(struct rb_root_cached *symbols)
182 {
183 	struct rb_node *nd;
184 	struct symbol *curr, *next;
185 
186 	if (symbol_conf.allow_aliases)
187 		return;
188 
189 	nd = rb_first_cached(symbols);
190 
191 	while (nd) {
192 		curr = rb_entry(nd, struct symbol, rb_node);
193 again:
194 		nd = rb_next(&curr->rb_node);
195 		next = rb_entry(nd, struct symbol, rb_node);
196 
197 		if (!nd)
198 			break;
199 
200 		if (curr->start != next->start)
201 			continue;
202 
203 		if (choose_best_symbol(curr, next) == SYMBOL_A) {
204 			rb_erase_cached(&next->rb_node, symbols);
205 			symbol__delete(next);
206 			goto again;
207 		} else {
208 			nd = rb_next(&curr->rb_node);
209 			rb_erase_cached(&curr->rb_node, symbols);
210 			symbol__delete(curr);
211 		}
212 	}
213 }
214 
215 /* Update zero-sized symbols using the address of the next symbol */
symbols__fixup_end(struct rb_root_cached * symbols,bool is_kallsyms)216 void symbols__fixup_end(struct rb_root_cached *symbols, bool is_kallsyms)
217 {
218 	struct rb_node *nd, *prevnd = rb_first_cached(symbols);
219 	struct symbol *curr, *prev;
220 
221 	if (prevnd == NULL)
222 		return;
223 
224 	curr = rb_entry(prevnd, struct symbol, rb_node);
225 
226 	for (nd = rb_next(prevnd); nd; nd = rb_next(nd)) {
227 		prev = curr;
228 		curr = rb_entry(nd, struct symbol, rb_node);
229 
230 		/*
231 		 * On some architecture kernel text segment start is located at
232 		 * some low memory address, while modules are located at high
233 		 * memory addresses (or vice versa).  The gap between end of
234 		 * kernel text segment and beginning of first module's text
235 		 * segment is very big.  Therefore do not fill this gap and do
236 		 * not assign it to the kernel dso map (kallsyms).
237 		 *
238 		 * In kallsyms, it determines module symbols using '[' character
239 		 * like in:
240 		 *   ffffffffc1937000 T hdmi_driver_init  [snd_hda_codec_hdmi]
241 		 */
242 		if (prev->end == prev->start) {
243 			/* Last kernel/module symbol mapped to end of page */
244 			if (is_kallsyms && (!strchr(prev->name, '[') !=
245 					    !strchr(curr->name, '[')))
246 				prev->end = roundup(prev->end + 4096, 4096);
247 			else
248 				prev->end = curr->start;
249 
250 			pr_debug4("%s sym:%s end:%#" PRIx64 "\n",
251 				  __func__, prev->name, prev->end);
252 		}
253 	}
254 
255 	/* Last entry */
256 	if (curr->end == curr->start)
257 		curr->end = roundup(curr->start, 4096) + 4096;
258 }
259 
maps__fixup_end(struct maps * maps)260 void maps__fixup_end(struct maps *maps)
261 {
262 	struct map *prev = NULL, *curr;
263 
264 	down_write(&maps->lock);
265 
266 	maps__for_each_entry(maps, curr) {
267 		if (prev != NULL && !prev->end)
268 			prev->end = curr->start;
269 
270 		prev = curr;
271 	}
272 
273 	/*
274 	 * We still haven't the actual symbols, so guess the
275 	 * last map final address.
276 	 */
277 	if (curr && !curr->end)
278 		curr->end = ~0ULL;
279 
280 	up_write(&maps->lock);
281 }
282 
symbol__new(u64 start,u64 len,u8 binding,u8 type,const char * name)283 struct symbol *symbol__new(u64 start, u64 len, u8 binding, u8 type, const char *name)
284 {
285 	size_t namelen = strlen(name) + 1;
286 	struct symbol *sym = calloc(1, (symbol_conf.priv_size +
287 					sizeof(*sym) + namelen));
288 	if (sym == NULL)
289 		return NULL;
290 
291 	if (symbol_conf.priv_size) {
292 		if (symbol_conf.init_annotation) {
293 			struct annotation *notes = (void *)sym;
294 			annotation__init(notes);
295 		}
296 		sym = ((void *)sym) + symbol_conf.priv_size;
297 	}
298 
299 	sym->start   = start;
300 	sym->end     = len ? start + len : start;
301 	sym->type    = type;
302 	sym->binding = binding;
303 	sym->namelen = namelen - 1;
304 
305 	pr_debug4("%s: %s %#" PRIx64 "-%#" PRIx64 "\n",
306 		  __func__, name, start, sym->end);
307 	memcpy(sym->name, name, namelen);
308 
309 	return sym;
310 }
311 
symbol__delete(struct symbol * sym)312 void symbol__delete(struct symbol *sym)
313 {
314 	if (symbol_conf.priv_size) {
315 		if (symbol_conf.init_annotation) {
316 			struct annotation *notes = symbol__annotation(sym);
317 
318 			annotation__exit(notes);
319 		}
320 	}
321 	free(((void *)sym) - symbol_conf.priv_size);
322 }
323 
symbols__delete(struct rb_root_cached * symbols)324 void symbols__delete(struct rb_root_cached *symbols)
325 {
326 	struct symbol *pos;
327 	struct rb_node *next = rb_first_cached(symbols);
328 
329 	while (next) {
330 		pos = rb_entry(next, struct symbol, rb_node);
331 		next = rb_next(&pos->rb_node);
332 		rb_erase_cached(&pos->rb_node, symbols);
333 		symbol__delete(pos);
334 	}
335 }
336 
__symbols__insert(struct rb_root_cached * symbols,struct symbol * sym,bool kernel)337 void __symbols__insert(struct rb_root_cached *symbols,
338 		       struct symbol *sym, bool kernel)
339 {
340 	struct rb_node **p = &symbols->rb_root.rb_node;
341 	struct rb_node *parent = NULL;
342 	const u64 ip = sym->start;
343 	struct symbol *s;
344 	bool leftmost = true;
345 
346 	if (kernel) {
347 		const char *name = sym->name;
348 		/*
349 		 * ppc64 uses function descriptors and appends a '.' to the
350 		 * start of every instruction address. Remove it.
351 		 */
352 		if (name[0] == '.')
353 			name++;
354 		sym->idle = symbol__is_idle(name);
355 	}
356 
357 	while (*p != NULL) {
358 		parent = *p;
359 		s = rb_entry(parent, struct symbol, rb_node);
360 		if (ip < s->start)
361 			p = &(*p)->rb_left;
362 		else {
363 			p = &(*p)->rb_right;
364 			leftmost = false;
365 		}
366 	}
367 	rb_link_node(&sym->rb_node, parent, p);
368 	rb_insert_color_cached(&sym->rb_node, symbols, leftmost);
369 }
370 
symbols__insert(struct rb_root_cached * symbols,struct symbol * sym)371 void symbols__insert(struct rb_root_cached *symbols, struct symbol *sym)
372 {
373 	__symbols__insert(symbols, sym, false);
374 }
375 
symbols__find(struct rb_root_cached * symbols,u64 ip)376 static struct symbol *symbols__find(struct rb_root_cached *symbols, u64 ip)
377 {
378 	struct rb_node *n;
379 
380 	if (symbols == NULL)
381 		return NULL;
382 
383 	n = symbols->rb_root.rb_node;
384 
385 	while (n) {
386 		struct symbol *s = rb_entry(n, struct symbol, rb_node);
387 
388 		if (ip < s->start)
389 			n = n->rb_left;
390 		else if (ip > s->end || (ip == s->end && ip != s->start))
391 			n = n->rb_right;
392 		else
393 			return s;
394 	}
395 
396 	return NULL;
397 }
398 
symbols__first(struct rb_root_cached * symbols)399 static struct symbol *symbols__first(struct rb_root_cached *symbols)
400 {
401 	struct rb_node *n = rb_first_cached(symbols);
402 
403 	if (n)
404 		return rb_entry(n, struct symbol, rb_node);
405 
406 	return NULL;
407 }
408 
symbols__last(struct rb_root_cached * symbols)409 static struct symbol *symbols__last(struct rb_root_cached *symbols)
410 {
411 	struct rb_node *n = rb_last(&symbols->rb_root);
412 
413 	if (n)
414 		return rb_entry(n, struct symbol, rb_node);
415 
416 	return NULL;
417 }
418 
symbols__next(struct symbol * sym)419 static struct symbol *symbols__next(struct symbol *sym)
420 {
421 	struct rb_node *n = rb_next(&sym->rb_node);
422 
423 	if (n)
424 		return rb_entry(n, struct symbol, rb_node);
425 
426 	return NULL;
427 }
428 
symbols__insert_by_name(struct rb_root_cached * symbols,struct symbol * sym)429 static void symbols__insert_by_name(struct rb_root_cached *symbols, struct symbol *sym)
430 {
431 	struct rb_node **p = &symbols->rb_root.rb_node;
432 	struct rb_node *parent = NULL;
433 	struct symbol_name_rb_node *symn, *s;
434 	bool leftmost = true;
435 
436 	symn = container_of(sym, struct symbol_name_rb_node, sym);
437 
438 	while (*p != NULL) {
439 		parent = *p;
440 		s = rb_entry(parent, struct symbol_name_rb_node, rb_node);
441 		if (strcmp(sym->name, s->sym.name) < 0)
442 			p = &(*p)->rb_left;
443 		else {
444 			p = &(*p)->rb_right;
445 			leftmost = false;
446 		}
447 	}
448 	rb_link_node(&symn->rb_node, parent, p);
449 	rb_insert_color_cached(&symn->rb_node, symbols, leftmost);
450 }
451 
symbols__sort_by_name(struct rb_root_cached * symbols,struct rb_root_cached * source)452 static void symbols__sort_by_name(struct rb_root_cached *symbols,
453 				  struct rb_root_cached *source)
454 {
455 	struct rb_node *nd;
456 
457 	for (nd = rb_first_cached(source); nd; nd = rb_next(nd)) {
458 		struct symbol *pos = rb_entry(nd, struct symbol, rb_node);
459 		symbols__insert_by_name(symbols, pos);
460 	}
461 }
462 
symbol__match_symbol_name(const char * name,const char * str,enum symbol_tag_include includes)463 int symbol__match_symbol_name(const char *name, const char *str,
464 			      enum symbol_tag_include includes)
465 {
466 	const char *versioning;
467 
468 	if (includes == SYMBOL_TAG_INCLUDE__DEFAULT_ONLY &&
469 	    (versioning = strstr(name, "@@"))) {
470 		int len = strlen(str);
471 
472 		if (len < versioning - name)
473 			len = versioning - name;
474 
475 		return arch__compare_symbol_names_n(name, str, len);
476 	} else
477 		return arch__compare_symbol_names(name, str);
478 }
479 
symbols__find_by_name(struct rb_root_cached * symbols,const char * name,enum symbol_tag_include includes)480 static struct symbol *symbols__find_by_name(struct rb_root_cached *symbols,
481 					    const char *name,
482 					    enum symbol_tag_include includes)
483 {
484 	struct rb_node *n;
485 	struct symbol_name_rb_node *s = NULL;
486 
487 	if (symbols == NULL)
488 		return NULL;
489 
490 	n = symbols->rb_root.rb_node;
491 
492 	while (n) {
493 		int cmp;
494 
495 		s = rb_entry(n, struct symbol_name_rb_node, rb_node);
496 		cmp = symbol__match_symbol_name(s->sym.name, name, includes);
497 
498 		if (cmp > 0)
499 			n = n->rb_left;
500 		else if (cmp < 0)
501 			n = n->rb_right;
502 		else
503 			break;
504 	}
505 
506 	if (n == NULL)
507 		return NULL;
508 
509 	if (includes != SYMBOL_TAG_INCLUDE__DEFAULT_ONLY)
510 		/* return first symbol that has same name (if any) */
511 		for (n = rb_prev(n); n; n = rb_prev(n)) {
512 			struct symbol_name_rb_node *tmp;
513 
514 			tmp = rb_entry(n, struct symbol_name_rb_node, rb_node);
515 			if (arch__compare_symbol_names(tmp->sym.name, s->sym.name))
516 				break;
517 
518 			s = tmp;
519 		}
520 
521 	return &s->sym;
522 }
523 
dso__reset_find_symbol_cache(struct dso * dso)524 void dso__reset_find_symbol_cache(struct dso *dso)
525 {
526 	dso->last_find_result.addr   = 0;
527 	dso->last_find_result.symbol = NULL;
528 }
529 
dso__insert_symbol(struct dso * dso,struct symbol * sym)530 void dso__insert_symbol(struct dso *dso, struct symbol *sym)
531 {
532 	__symbols__insert(&dso->symbols, sym, dso->kernel);
533 
534 	/* update the symbol cache if necessary */
535 	if (dso->last_find_result.addr >= sym->start &&
536 	    (dso->last_find_result.addr < sym->end ||
537 	    sym->start == sym->end)) {
538 		dso->last_find_result.symbol = sym;
539 	}
540 }
541 
dso__delete_symbol(struct dso * dso,struct symbol * sym)542 void dso__delete_symbol(struct dso *dso, struct symbol *sym)
543 {
544 	rb_erase_cached(&sym->rb_node, &dso->symbols);
545 	symbol__delete(sym);
546 	dso__reset_find_symbol_cache(dso);
547 }
548 
dso__find_symbol(struct dso * dso,u64 addr)549 struct symbol *dso__find_symbol(struct dso *dso, u64 addr)
550 {
551 	if (dso->last_find_result.addr != addr || dso->last_find_result.symbol == NULL) {
552 		dso->last_find_result.addr   = addr;
553 		dso->last_find_result.symbol = symbols__find(&dso->symbols, addr);
554 	}
555 
556 	return dso->last_find_result.symbol;
557 }
558 
dso__first_symbol(struct dso * dso)559 struct symbol *dso__first_symbol(struct dso *dso)
560 {
561 	return symbols__first(&dso->symbols);
562 }
563 
dso__last_symbol(struct dso * dso)564 struct symbol *dso__last_symbol(struct dso *dso)
565 {
566 	return symbols__last(&dso->symbols);
567 }
568 
dso__next_symbol(struct symbol * sym)569 struct symbol *dso__next_symbol(struct symbol *sym)
570 {
571 	return symbols__next(sym);
572 }
573 
symbol__next_by_name(struct symbol * sym)574 struct symbol *symbol__next_by_name(struct symbol *sym)
575 {
576 	struct symbol_name_rb_node *s = container_of(sym, struct symbol_name_rb_node, sym);
577 	struct rb_node *n = rb_next(&s->rb_node);
578 
579 	return n ? &rb_entry(n, struct symbol_name_rb_node, rb_node)->sym : NULL;
580 }
581 
582  /*
583   * Returns first symbol that matched with @name.
584   */
dso__find_symbol_by_name(struct dso * dso,const char * name)585 struct symbol *dso__find_symbol_by_name(struct dso *dso, const char *name)
586 {
587 	struct symbol *s = symbols__find_by_name(&dso->symbol_names, name,
588 						 SYMBOL_TAG_INCLUDE__NONE);
589 	if (!s)
590 		s = symbols__find_by_name(&dso->symbol_names, name,
591 					  SYMBOL_TAG_INCLUDE__DEFAULT_ONLY);
592 	return s;
593 }
594 
dso__sort_by_name(struct dso * dso)595 void dso__sort_by_name(struct dso *dso)
596 {
597 	dso__set_sorted_by_name(dso);
598 	return symbols__sort_by_name(&dso->symbol_names, &dso->symbols);
599 }
600 
601 /*
602  * While we find nice hex chars, build a long_val.
603  * Return number of chars processed.
604  */
hex2u64(const char * ptr,u64 * long_val)605 static int hex2u64(const char *ptr, u64 *long_val)
606 {
607 	char *p;
608 
609 	*long_val = strtoull(ptr, &p, 16);
610 
611 	return p - ptr;
612 }
613 
614 
modules__parse(const char * filename,void * arg,int (* process_module)(void * arg,const char * name,u64 start,u64 size))615 int modules__parse(const char *filename, void *arg,
616 		   int (*process_module)(void *arg, const char *name,
617 					 u64 start, u64 size))
618 {
619 	char *line = NULL;
620 	size_t n;
621 	FILE *file;
622 	int err = 0;
623 
624 	file = fopen(filename, "r");
625 	if (file == NULL)
626 		return -1;
627 
628 	while (1) {
629 		char name[PATH_MAX];
630 		u64 start, size;
631 		char *sep, *endptr;
632 		ssize_t line_len;
633 
634 		line_len = getline(&line, &n, file);
635 		if (line_len < 0) {
636 			if (feof(file))
637 				break;
638 			err = -1;
639 			goto out;
640 		}
641 
642 		if (!line) {
643 			err = -1;
644 			goto out;
645 		}
646 
647 		line[--line_len] = '\0'; /* \n */
648 
649 		sep = strrchr(line, 'x');
650 		if (sep == NULL)
651 			continue;
652 
653 		hex2u64(sep + 1, &start);
654 
655 		sep = strchr(line, ' ');
656 		if (sep == NULL)
657 			continue;
658 
659 		*sep = '\0';
660 
661 		scnprintf(name, sizeof(name), "[%s]", line);
662 
663 		size = strtoul(sep + 1, &endptr, 0);
664 		if (*endptr != ' ' && *endptr != '\t')
665 			continue;
666 
667 		err = process_module(arg, name, start, size);
668 		if (err)
669 			break;
670 	}
671 out:
672 	free(line);
673 	fclose(file);
674 	return err;
675 }
676 
677 /*
678  * These are symbols in the kernel image, so make sure that
679  * sym is from a kernel DSO.
680  */
symbol__is_idle(const char * name)681 static bool symbol__is_idle(const char *name)
682 {
683 	const char * const idle_symbols[] = {
684 		"acpi_idle_do_entry",
685 		"acpi_processor_ffh_cstate_enter",
686 		"arch_cpu_idle",
687 		"cpu_idle",
688 		"cpu_startup_entry",
689 		"idle_cpu",
690 		"intel_idle",
691 		"default_idle",
692 		"native_safe_halt",
693 		"enter_idle",
694 		"exit_idle",
695 		"mwait_idle",
696 		"mwait_idle_with_hints",
697 		"mwait_idle_with_hints.constprop.0",
698 		"poll_idle",
699 		"ppc64_runlatch_off",
700 		"pseries_dedicated_idle_sleep",
701 		"psw_idle",
702 		"psw_idle_exit",
703 		NULL
704 	};
705 	int i;
706 	static struct strlist *idle_symbols_list;
707 
708 	if (idle_symbols_list)
709 		return strlist__has_entry(idle_symbols_list, name);
710 
711 	idle_symbols_list = strlist__new(NULL, NULL);
712 
713 	for (i = 0; idle_symbols[i]; i++)
714 		strlist__add(idle_symbols_list, idle_symbols[i]);
715 
716 	return strlist__has_entry(idle_symbols_list, name);
717 }
718 
map__process_kallsym_symbol(void * arg,const char * name,char type,u64 start)719 static int map__process_kallsym_symbol(void *arg, const char *name,
720 				       char type, u64 start)
721 {
722 	struct symbol *sym;
723 	struct dso *dso = arg;
724 	struct rb_root_cached *root = &dso->symbols;
725 
726 	if (!symbol_type__filter(type))
727 		return 0;
728 
729 	/* Ignore local symbols for ARM modules */
730 	if (name[0] == '$')
731 		return 0;
732 
733 	/*
734 	 * module symbols are not sorted so we add all
735 	 * symbols, setting length to 0, and rely on
736 	 * symbols__fixup_end() to fix it up.
737 	 */
738 	sym = symbol__new(start, 0, kallsyms2elf_binding(type), kallsyms2elf_type(type), name);
739 	if (sym == NULL)
740 		return -ENOMEM;
741 	/*
742 	 * We will pass the symbols to the filter later, in
743 	 * map__split_kallsyms, when we have split the maps per module
744 	 */
745 	__symbols__insert(root, sym, !strchr(name, '['));
746 
747 	return 0;
748 }
749 
750 /*
751  * Loads the function entries in /proc/kallsyms into kernel_map->dso,
752  * so that we can in the next step set the symbol ->end address and then
753  * call kernel_maps__split_kallsyms.
754  */
dso__load_all_kallsyms(struct dso * dso,const char * filename)755 static int dso__load_all_kallsyms(struct dso *dso, const char *filename)
756 {
757 	return kallsyms__parse(filename, dso, map__process_kallsym_symbol);
758 }
759 
maps__split_kallsyms_for_kcore(struct maps * kmaps,struct dso * dso)760 static int maps__split_kallsyms_for_kcore(struct maps *kmaps, struct dso *dso)
761 {
762 	struct map *curr_map;
763 	struct symbol *pos;
764 	int count = 0;
765 	struct rb_root_cached old_root = dso->symbols;
766 	struct rb_root_cached *root = &dso->symbols;
767 	struct rb_node *next = rb_first_cached(root);
768 
769 	if (!kmaps)
770 		return -1;
771 
772 	*root = RB_ROOT_CACHED;
773 
774 	while (next) {
775 		char *module;
776 
777 		pos = rb_entry(next, struct symbol, rb_node);
778 		next = rb_next(&pos->rb_node);
779 
780 		rb_erase_cached(&pos->rb_node, &old_root);
781 		RB_CLEAR_NODE(&pos->rb_node);
782 		module = strchr(pos->name, '\t');
783 		if (module)
784 			*module = '\0';
785 
786 		curr_map = maps__find(kmaps, pos->start);
787 
788 		if (!curr_map) {
789 			symbol__delete(pos);
790 			continue;
791 		}
792 
793 		pos->start -= curr_map->start - curr_map->pgoff;
794 		if (pos->end > curr_map->end)
795 			pos->end = curr_map->end;
796 		if (pos->end)
797 			pos->end -= curr_map->start - curr_map->pgoff;
798 		symbols__insert(&curr_map->dso->symbols, pos);
799 		++count;
800 	}
801 
802 	/* Symbols have been adjusted */
803 	dso->adjust_symbols = 1;
804 
805 	return count;
806 }
807 
808 /*
809  * Split the symbols into maps, making sure there are no overlaps, i.e. the
810  * kernel range is broken in several maps, named [kernel].N, as we don't have
811  * the original ELF section names vmlinux have.
812  */
maps__split_kallsyms(struct maps * kmaps,struct dso * dso,u64 delta,struct map * initial_map)813 static int maps__split_kallsyms(struct maps *kmaps, struct dso *dso, u64 delta,
814 				struct map *initial_map)
815 {
816 	struct machine *machine;
817 	struct map *curr_map = initial_map;
818 	struct symbol *pos;
819 	int count = 0, moved = 0;
820 	struct rb_root_cached *root = &dso->symbols;
821 	struct rb_node *next = rb_first_cached(root);
822 	int kernel_range = 0;
823 	bool x86_64;
824 
825 	if (!kmaps)
826 		return -1;
827 
828 	machine = kmaps->machine;
829 
830 	x86_64 = machine__is(machine, "x86_64");
831 
832 	while (next) {
833 		char *module;
834 
835 		pos = rb_entry(next, struct symbol, rb_node);
836 		next = rb_next(&pos->rb_node);
837 
838 		module = strchr(pos->name, '\t');
839 		if (module) {
840 			if (!symbol_conf.use_modules)
841 				goto discard_symbol;
842 
843 			*module++ = '\0';
844 
845 			if (strcmp(curr_map->dso->short_name, module)) {
846 				if (curr_map != initial_map &&
847 				    dso->kernel == DSO_SPACE__KERNEL_GUEST &&
848 				    machine__is_default_guest(machine)) {
849 					/*
850 					 * We assume all symbols of a module are
851 					 * continuous in * kallsyms, so curr_map
852 					 * points to a module and all its
853 					 * symbols are in its kmap. Mark it as
854 					 * loaded.
855 					 */
856 					dso__set_loaded(curr_map->dso);
857 				}
858 
859 				curr_map = maps__find_by_name(kmaps, module);
860 				if (curr_map == NULL) {
861 					pr_debug("%s/proc/{kallsyms,modules} "
862 					         "inconsistency while looking "
863 						 "for \"%s\" module!\n",
864 						 machine->root_dir, module);
865 					curr_map = initial_map;
866 					goto discard_symbol;
867 				}
868 
869 				if (curr_map->dso->loaded &&
870 				    !machine__is_default_guest(machine))
871 					goto discard_symbol;
872 			}
873 			/*
874 			 * So that we look just like we get from .ko files,
875 			 * i.e. not prelinked, relative to initial_map->start.
876 			 */
877 			pos->start = curr_map->map_ip(curr_map, pos->start);
878 			pos->end   = curr_map->map_ip(curr_map, pos->end);
879 		} else if (x86_64 && is_entry_trampoline(pos->name)) {
880 			/*
881 			 * These symbols are not needed anymore since the
882 			 * trampoline maps refer to the text section and it's
883 			 * symbols instead. Avoid having to deal with
884 			 * relocations, and the assumption that the first symbol
885 			 * is the start of kernel text, by simply removing the
886 			 * symbols at this point.
887 			 */
888 			goto discard_symbol;
889 		} else if (curr_map != initial_map) {
890 			char dso_name[PATH_MAX];
891 			struct dso *ndso;
892 
893 			if (delta) {
894 				/* Kernel was relocated at boot time */
895 				pos->start -= delta;
896 				pos->end -= delta;
897 			}
898 
899 			if (count == 0) {
900 				curr_map = initial_map;
901 				goto add_symbol;
902 			}
903 
904 			if (dso->kernel == DSO_SPACE__KERNEL_GUEST)
905 				snprintf(dso_name, sizeof(dso_name),
906 					"[guest.kernel].%d",
907 					kernel_range++);
908 			else
909 				snprintf(dso_name, sizeof(dso_name),
910 					"[kernel].%d",
911 					kernel_range++);
912 
913 			ndso = dso__new(dso_name);
914 			if (ndso == NULL)
915 				return -1;
916 
917 			ndso->kernel = dso->kernel;
918 
919 			curr_map = map__new2(pos->start, ndso);
920 			if (curr_map == NULL) {
921 				dso__put(ndso);
922 				return -1;
923 			}
924 
925 			curr_map->map_ip = curr_map->unmap_ip = identity__map_ip;
926 			maps__insert(kmaps, curr_map);
927 			++kernel_range;
928 		} else if (delta) {
929 			/* Kernel was relocated at boot time */
930 			pos->start -= delta;
931 			pos->end -= delta;
932 		}
933 add_symbol:
934 		if (curr_map != initial_map) {
935 			rb_erase_cached(&pos->rb_node, root);
936 			symbols__insert(&curr_map->dso->symbols, pos);
937 			++moved;
938 		} else
939 			++count;
940 
941 		continue;
942 discard_symbol:
943 		rb_erase_cached(&pos->rb_node, root);
944 		symbol__delete(pos);
945 	}
946 
947 	if (curr_map != initial_map &&
948 	    dso->kernel == DSO_SPACE__KERNEL_GUEST &&
949 	    machine__is_default_guest(kmaps->machine)) {
950 		dso__set_loaded(curr_map->dso);
951 	}
952 
953 	return count + moved;
954 }
955 
symbol__restricted_filename(const char * filename,const char * restricted_filename)956 bool symbol__restricted_filename(const char *filename,
957 				 const char *restricted_filename)
958 {
959 	bool restricted = false;
960 
961 	if (symbol_conf.kptr_restrict) {
962 		char *r = realpath(filename, NULL);
963 
964 		if (r != NULL) {
965 			restricted = strcmp(r, restricted_filename) == 0;
966 			free(r);
967 			return restricted;
968 		}
969 	}
970 
971 	return restricted;
972 }
973 
974 struct module_info {
975 	struct rb_node rb_node;
976 	char *name;
977 	u64 start;
978 };
979 
add_module(struct module_info * mi,struct rb_root * modules)980 static void add_module(struct module_info *mi, struct rb_root *modules)
981 {
982 	struct rb_node **p = &modules->rb_node;
983 	struct rb_node *parent = NULL;
984 	struct module_info *m;
985 
986 	while (*p != NULL) {
987 		parent = *p;
988 		m = rb_entry(parent, struct module_info, rb_node);
989 		if (strcmp(mi->name, m->name) < 0)
990 			p = &(*p)->rb_left;
991 		else
992 			p = &(*p)->rb_right;
993 	}
994 	rb_link_node(&mi->rb_node, parent, p);
995 	rb_insert_color(&mi->rb_node, modules);
996 }
997 
delete_modules(struct rb_root * modules)998 static void delete_modules(struct rb_root *modules)
999 {
1000 	struct module_info *mi;
1001 	struct rb_node *next = rb_first(modules);
1002 
1003 	while (next) {
1004 		mi = rb_entry(next, struct module_info, rb_node);
1005 		next = rb_next(&mi->rb_node);
1006 		rb_erase(&mi->rb_node, modules);
1007 		zfree(&mi->name);
1008 		free(mi);
1009 	}
1010 }
1011 
find_module(const char * name,struct rb_root * modules)1012 static struct module_info *find_module(const char *name,
1013 				       struct rb_root *modules)
1014 {
1015 	struct rb_node *n = modules->rb_node;
1016 
1017 	while (n) {
1018 		struct module_info *m;
1019 		int cmp;
1020 
1021 		m = rb_entry(n, struct module_info, rb_node);
1022 		cmp = strcmp(name, m->name);
1023 		if (cmp < 0)
1024 			n = n->rb_left;
1025 		else if (cmp > 0)
1026 			n = n->rb_right;
1027 		else
1028 			return m;
1029 	}
1030 
1031 	return NULL;
1032 }
1033 
__read_proc_modules(void * arg,const char * name,u64 start,u64 size __maybe_unused)1034 static int __read_proc_modules(void *arg, const char *name, u64 start,
1035 			       u64 size __maybe_unused)
1036 {
1037 	struct rb_root *modules = arg;
1038 	struct module_info *mi;
1039 
1040 	mi = zalloc(sizeof(struct module_info));
1041 	if (!mi)
1042 		return -ENOMEM;
1043 
1044 	mi->name = strdup(name);
1045 	mi->start = start;
1046 
1047 	if (!mi->name) {
1048 		free(mi);
1049 		return -ENOMEM;
1050 	}
1051 
1052 	add_module(mi, modules);
1053 
1054 	return 0;
1055 }
1056 
read_proc_modules(const char * filename,struct rb_root * modules)1057 static int read_proc_modules(const char *filename, struct rb_root *modules)
1058 {
1059 	if (symbol__restricted_filename(filename, "/proc/modules"))
1060 		return -1;
1061 
1062 	if (modules__parse(filename, modules, __read_proc_modules)) {
1063 		delete_modules(modules);
1064 		return -1;
1065 	}
1066 
1067 	return 0;
1068 }
1069 
compare_proc_modules(const char * from,const char * to)1070 int compare_proc_modules(const char *from, const char *to)
1071 {
1072 	struct rb_root from_modules = RB_ROOT;
1073 	struct rb_root to_modules = RB_ROOT;
1074 	struct rb_node *from_node, *to_node;
1075 	struct module_info *from_m, *to_m;
1076 	int ret = -1;
1077 
1078 	if (read_proc_modules(from, &from_modules))
1079 		return -1;
1080 
1081 	if (read_proc_modules(to, &to_modules))
1082 		goto out_delete_from;
1083 
1084 	from_node = rb_first(&from_modules);
1085 	to_node = rb_first(&to_modules);
1086 	while (from_node) {
1087 		if (!to_node)
1088 			break;
1089 
1090 		from_m = rb_entry(from_node, struct module_info, rb_node);
1091 		to_m = rb_entry(to_node, struct module_info, rb_node);
1092 
1093 		if (from_m->start != to_m->start ||
1094 		    strcmp(from_m->name, to_m->name))
1095 			break;
1096 
1097 		from_node = rb_next(from_node);
1098 		to_node = rb_next(to_node);
1099 	}
1100 
1101 	if (!from_node && !to_node)
1102 		ret = 0;
1103 
1104 	delete_modules(&to_modules);
1105 out_delete_from:
1106 	delete_modules(&from_modules);
1107 
1108 	return ret;
1109 }
1110 
do_validate_kcore_modules(const char * filename,struct maps * kmaps)1111 static int do_validate_kcore_modules(const char *filename, struct maps *kmaps)
1112 {
1113 	struct rb_root modules = RB_ROOT;
1114 	struct map *old_map;
1115 	int err;
1116 
1117 	err = read_proc_modules(filename, &modules);
1118 	if (err)
1119 		return err;
1120 
1121 	maps__for_each_entry(kmaps, old_map) {
1122 		struct module_info *mi;
1123 
1124 		if (!__map__is_kmodule(old_map)) {
1125 			continue;
1126 		}
1127 
1128 		/* Module must be in memory at the same address */
1129 		mi = find_module(old_map->dso->short_name, &modules);
1130 		if (!mi || mi->start != old_map->start) {
1131 			err = -EINVAL;
1132 			goto out;
1133 		}
1134 	}
1135 out:
1136 	delete_modules(&modules);
1137 	return err;
1138 }
1139 
1140 /*
1141  * If kallsyms is referenced by name then we look for filename in the same
1142  * directory.
1143  */
filename_from_kallsyms_filename(char * filename,const char * base_name,const char * kallsyms_filename)1144 static bool filename_from_kallsyms_filename(char *filename,
1145 					    const char *base_name,
1146 					    const char *kallsyms_filename)
1147 {
1148 	char *name;
1149 
1150 	strcpy(filename, kallsyms_filename);
1151 	name = strrchr(filename, '/');
1152 	if (!name)
1153 		return false;
1154 
1155 	name += 1;
1156 
1157 	if (!strcmp(name, "kallsyms")) {
1158 		strcpy(name, base_name);
1159 		return true;
1160 	}
1161 
1162 	return false;
1163 }
1164 
validate_kcore_modules(const char * kallsyms_filename,struct map * map)1165 static int validate_kcore_modules(const char *kallsyms_filename,
1166 				  struct map *map)
1167 {
1168 	struct maps *kmaps = map__kmaps(map);
1169 	char modules_filename[PATH_MAX];
1170 
1171 	if (!kmaps)
1172 		return -EINVAL;
1173 
1174 	if (!filename_from_kallsyms_filename(modules_filename, "modules",
1175 					     kallsyms_filename))
1176 		return -EINVAL;
1177 
1178 	if (do_validate_kcore_modules(modules_filename, kmaps))
1179 		return -EINVAL;
1180 
1181 	return 0;
1182 }
1183 
validate_kcore_addresses(const char * kallsyms_filename,struct map * map)1184 static int validate_kcore_addresses(const char *kallsyms_filename,
1185 				    struct map *map)
1186 {
1187 	struct kmap *kmap = map__kmap(map);
1188 
1189 	if (!kmap)
1190 		return -EINVAL;
1191 
1192 	if (kmap->ref_reloc_sym && kmap->ref_reloc_sym->name) {
1193 		u64 start;
1194 
1195 		if (kallsyms__get_function_start(kallsyms_filename,
1196 						 kmap->ref_reloc_sym->name, &start))
1197 			return -ENOENT;
1198 		if (start != kmap->ref_reloc_sym->addr)
1199 			return -EINVAL;
1200 	}
1201 
1202 	return validate_kcore_modules(kallsyms_filename, map);
1203 }
1204 
1205 struct kcore_mapfn_data {
1206 	struct dso *dso;
1207 	struct list_head maps;
1208 };
1209 
kcore_mapfn(u64 start,u64 len,u64 pgoff,void * data)1210 static int kcore_mapfn(u64 start, u64 len, u64 pgoff, void *data)
1211 {
1212 	struct kcore_mapfn_data *md = data;
1213 	struct map *map;
1214 
1215 	map = map__new2(start, md->dso);
1216 	if (map == NULL)
1217 		return -ENOMEM;
1218 
1219 	map->end = map->start + len;
1220 	map->pgoff = pgoff;
1221 
1222 	list_add(&map->node, &md->maps);
1223 
1224 	return 0;
1225 }
1226 
1227 /*
1228  * Merges map into maps by splitting the new map within the existing map
1229  * regions.
1230  */
maps__merge_in(struct maps * kmaps,struct map * new_map)1231 int maps__merge_in(struct maps *kmaps, struct map *new_map)
1232 {
1233 	struct map *old_map;
1234 	LIST_HEAD(merged);
1235 
1236 	maps__for_each_entry(kmaps, old_map) {
1237 		/* no overload with this one */
1238 		if (new_map->end < old_map->start ||
1239 		    new_map->start >= old_map->end)
1240 			continue;
1241 
1242 		if (new_map->start < old_map->start) {
1243 			/*
1244 			 * |new......
1245 			 *       |old....
1246 			 */
1247 			if (new_map->end < old_map->end) {
1248 				/*
1249 				 * |new......|     -> |new..|
1250 				 *       |old....| ->       |old....|
1251 				 */
1252 				new_map->end = old_map->start;
1253 			} else {
1254 				/*
1255 				 * |new.............| -> |new..|       |new..|
1256 				 *       |old....|    ->       |old....|
1257 				 */
1258 				struct map *m = map__clone(new_map);
1259 
1260 				if (!m)
1261 					return -ENOMEM;
1262 
1263 				m->end = old_map->start;
1264 				list_add_tail(&m->node, &merged);
1265 				new_map->pgoff += old_map->end - new_map->start;
1266 				new_map->start = old_map->end;
1267 			}
1268 		} else {
1269 			/*
1270 			 *      |new......
1271 			 * |old....
1272 			 */
1273 			if (new_map->end < old_map->end) {
1274 				/*
1275 				 *      |new..|   -> x
1276 				 * |old.........| -> |old.........|
1277 				 */
1278 				map__put(new_map);
1279 				new_map = NULL;
1280 				break;
1281 			} else {
1282 				/*
1283 				 *      |new......| ->         |new...|
1284 				 * |old....|        -> |old....|
1285 				 */
1286 				new_map->pgoff += old_map->end - new_map->start;
1287 				new_map->start = old_map->end;
1288 			}
1289 		}
1290 	}
1291 
1292 	while (!list_empty(&merged)) {
1293 		old_map = list_entry(merged.next, struct map, node);
1294 		list_del_init(&old_map->node);
1295 		maps__insert(kmaps, old_map);
1296 		map__put(old_map);
1297 	}
1298 
1299 	if (new_map) {
1300 		maps__insert(kmaps, new_map);
1301 		map__put(new_map);
1302 	}
1303 	return 0;
1304 }
1305 
dso__load_kcore(struct dso * dso,struct map * map,const char * kallsyms_filename)1306 static int dso__load_kcore(struct dso *dso, struct map *map,
1307 			   const char *kallsyms_filename)
1308 {
1309 	struct maps *kmaps = map__kmaps(map);
1310 	struct kcore_mapfn_data md;
1311 	struct map *old_map, *new_map, *replacement_map = NULL, *next;
1312 	struct machine *machine;
1313 	bool is_64_bit;
1314 	int err, fd;
1315 	char kcore_filename[PATH_MAX];
1316 	u64 stext;
1317 
1318 	if (!kmaps)
1319 		return -EINVAL;
1320 
1321 	machine = kmaps->machine;
1322 
1323 	/* This function requires that the map is the kernel map */
1324 	if (!__map__is_kernel(map))
1325 		return -EINVAL;
1326 
1327 	if (!filename_from_kallsyms_filename(kcore_filename, "kcore",
1328 					     kallsyms_filename))
1329 		return -EINVAL;
1330 
1331 	/* Modules and kernel must be present at their original addresses */
1332 	if (validate_kcore_addresses(kallsyms_filename, map))
1333 		return -EINVAL;
1334 
1335 	md.dso = dso;
1336 	INIT_LIST_HEAD(&md.maps);
1337 
1338 	fd = open(kcore_filename, O_RDONLY);
1339 	if (fd < 0) {
1340 		pr_debug("Failed to open %s. Note /proc/kcore requires CAP_SYS_RAWIO capability to access.\n",
1341 			 kcore_filename);
1342 		return -EINVAL;
1343 	}
1344 
1345 	/* Read new maps into temporary lists */
1346 	err = file__read_maps(fd, map->prot & PROT_EXEC, kcore_mapfn, &md,
1347 			      &is_64_bit);
1348 	if (err)
1349 		goto out_err;
1350 	dso->is_64_bit = is_64_bit;
1351 
1352 	if (list_empty(&md.maps)) {
1353 		err = -EINVAL;
1354 		goto out_err;
1355 	}
1356 
1357 	/* Remove old maps */
1358 	maps__for_each_entry_safe(kmaps, old_map, next) {
1359 		/*
1360 		 * We need to preserve eBPF maps even if they are
1361 		 * covered by kcore, because we need to access
1362 		 * eBPF dso for source data.
1363 		 */
1364 		if (old_map != map && !__map__is_bpf_prog(old_map))
1365 			maps__remove(kmaps, old_map);
1366 	}
1367 	machine->trampolines_mapped = false;
1368 
1369 	/* Find the kernel map using the '_stext' symbol */
1370 	if (!kallsyms__get_function_start(kallsyms_filename, "_stext", &stext)) {
1371 		list_for_each_entry(new_map, &md.maps, node) {
1372 			if (stext >= new_map->start && stext < new_map->end) {
1373 				replacement_map = new_map;
1374 				break;
1375 			}
1376 		}
1377 	}
1378 
1379 	if (!replacement_map)
1380 		replacement_map = list_entry(md.maps.next, struct map, node);
1381 
1382 	/* Add new maps */
1383 	while (!list_empty(&md.maps)) {
1384 		new_map = list_entry(md.maps.next, struct map, node);
1385 		list_del_init(&new_map->node);
1386 		if (new_map == replacement_map) {
1387 			map->start	= new_map->start;
1388 			map->end	= new_map->end;
1389 			map->pgoff	= new_map->pgoff;
1390 			map->map_ip	= new_map->map_ip;
1391 			map->unmap_ip	= new_map->unmap_ip;
1392 			/* Ensure maps are correctly ordered */
1393 			map__get(map);
1394 			maps__remove(kmaps, map);
1395 			maps__insert(kmaps, map);
1396 			map__put(map);
1397 			map__put(new_map);
1398 		} else {
1399 			/*
1400 			 * Merge kcore map into existing maps,
1401 			 * and ensure that current maps (eBPF)
1402 			 * stay intact.
1403 			 */
1404 			if (maps__merge_in(kmaps, new_map))
1405 				goto out_err;
1406 		}
1407 	}
1408 
1409 	if (machine__is(machine, "x86_64")) {
1410 		u64 addr;
1411 
1412 		/*
1413 		 * If one of the corresponding symbols is there, assume the
1414 		 * entry trampoline maps are too.
1415 		 */
1416 		if (!kallsyms__get_function_start(kallsyms_filename,
1417 						  ENTRY_TRAMPOLINE_NAME,
1418 						  &addr))
1419 			machine->trampolines_mapped = true;
1420 	}
1421 
1422 	/*
1423 	 * Set the data type and long name so that kcore can be read via
1424 	 * dso__data_read_addr().
1425 	 */
1426 	if (dso->kernel == DSO_SPACE__KERNEL_GUEST)
1427 		dso->binary_type = DSO_BINARY_TYPE__GUEST_KCORE;
1428 	else
1429 		dso->binary_type = DSO_BINARY_TYPE__KCORE;
1430 	dso__set_long_name(dso, strdup(kcore_filename), true);
1431 
1432 	close(fd);
1433 
1434 	if (map->prot & PROT_EXEC)
1435 		pr_debug("Using %s for kernel object code\n", kcore_filename);
1436 	else
1437 		pr_debug("Using %s for kernel data\n", kcore_filename);
1438 
1439 	return 0;
1440 
1441 out_err:
1442 	while (!list_empty(&md.maps)) {
1443 		map = list_entry(md.maps.next, struct map, node);
1444 		list_del_init(&map->node);
1445 		map__put(map);
1446 	}
1447 	close(fd);
1448 	return -EINVAL;
1449 }
1450 
1451 /*
1452  * If the kernel is relocated at boot time, kallsyms won't match.  Compute the
1453  * delta based on the relocation reference symbol.
1454  */
kallsyms__delta(struct kmap * kmap,const char * filename,u64 * delta)1455 static int kallsyms__delta(struct kmap *kmap, const char *filename, u64 *delta)
1456 {
1457 	u64 addr;
1458 
1459 	if (!kmap->ref_reloc_sym || !kmap->ref_reloc_sym->name)
1460 		return 0;
1461 
1462 	if (kallsyms__get_function_start(filename, kmap->ref_reloc_sym->name, &addr))
1463 		return -1;
1464 
1465 	*delta = addr - kmap->ref_reloc_sym->addr;
1466 	return 0;
1467 }
1468 
__dso__load_kallsyms(struct dso * dso,const char * filename,struct map * map,bool no_kcore)1469 int __dso__load_kallsyms(struct dso *dso, const char *filename,
1470 			 struct map *map, bool no_kcore)
1471 {
1472 	struct kmap *kmap = map__kmap(map);
1473 	u64 delta = 0;
1474 
1475 	if (symbol__restricted_filename(filename, "/proc/kallsyms"))
1476 		return -1;
1477 
1478 	if (!kmap || !kmap->kmaps)
1479 		return -1;
1480 
1481 	if (dso__load_all_kallsyms(dso, filename) < 0)
1482 		return -1;
1483 
1484 	if (kallsyms__delta(kmap, filename, &delta))
1485 		return -1;
1486 
1487 	symbols__fixup_end(&dso->symbols, true);
1488 	symbols__fixup_duplicate(&dso->symbols);
1489 
1490 	if (dso->kernel == DSO_SPACE__KERNEL_GUEST)
1491 		dso->symtab_type = DSO_BINARY_TYPE__GUEST_KALLSYMS;
1492 	else
1493 		dso->symtab_type = DSO_BINARY_TYPE__KALLSYMS;
1494 
1495 	if (!no_kcore && !dso__load_kcore(dso, map, filename))
1496 		return maps__split_kallsyms_for_kcore(kmap->kmaps, dso);
1497 	else
1498 		return maps__split_kallsyms(kmap->kmaps, dso, delta, map);
1499 }
1500 
dso__load_kallsyms(struct dso * dso,const char * filename,struct map * map)1501 int dso__load_kallsyms(struct dso *dso, const char *filename,
1502 		       struct map *map)
1503 {
1504 	return __dso__load_kallsyms(dso, filename, map, false);
1505 }
1506 
dso__load_perf_map(const char * map_path,struct dso * dso)1507 static int dso__load_perf_map(const char *map_path, struct dso *dso)
1508 {
1509 	char *line = NULL;
1510 	size_t n;
1511 	FILE *file;
1512 	int nr_syms = 0;
1513 
1514 	file = fopen(map_path, "r");
1515 	if (file == NULL)
1516 		goto out_failure;
1517 
1518 	while (!feof(file)) {
1519 		u64 start, size;
1520 		struct symbol *sym;
1521 		int line_len, len;
1522 
1523 		line_len = getline(&line, &n, file);
1524 		if (line_len < 0)
1525 			break;
1526 
1527 		if (!line)
1528 			goto out_failure;
1529 
1530 		line[--line_len] = '\0'; /* \n */
1531 
1532 		len = hex2u64(line, &start);
1533 
1534 		len++;
1535 		if (len + 2 >= line_len)
1536 			continue;
1537 
1538 		len += hex2u64(line + len, &size);
1539 
1540 		len++;
1541 		if (len + 2 >= line_len)
1542 			continue;
1543 
1544 		sym = symbol__new(start, size, STB_GLOBAL, STT_FUNC, line + len);
1545 
1546 		if (sym == NULL)
1547 			goto out_delete_line;
1548 
1549 		symbols__insert(&dso->symbols, sym);
1550 		nr_syms++;
1551 	}
1552 
1553 	free(line);
1554 	fclose(file);
1555 
1556 	return nr_syms;
1557 
1558 out_delete_line:
1559 	free(line);
1560 out_failure:
1561 	return -1;
1562 }
1563 
1564 #ifdef HAVE_LIBBFD_SUPPORT
1565 #define PACKAGE 'perf'
1566 #include <bfd.h>
1567 
bfd_symbols__cmpvalue(const void * a,const void * b)1568 static int bfd_symbols__cmpvalue(const void *a, const void *b)
1569 {
1570 	const asymbol *as = *(const asymbol **)a, *bs = *(const asymbol **)b;
1571 
1572 	if (bfd_asymbol_value(as) != bfd_asymbol_value(bs))
1573 		return bfd_asymbol_value(as) - bfd_asymbol_value(bs);
1574 
1575 	return bfd_asymbol_name(as)[0] - bfd_asymbol_name(bs)[0];
1576 }
1577 
bfd2elf_binding(asymbol * symbol)1578 static int bfd2elf_binding(asymbol *symbol)
1579 {
1580 	if (symbol->flags & BSF_WEAK)
1581 		return STB_WEAK;
1582 	if (symbol->flags & BSF_GLOBAL)
1583 		return STB_GLOBAL;
1584 	if (symbol->flags & BSF_LOCAL)
1585 		return STB_LOCAL;
1586 	return -1;
1587 }
1588 
dso__load_bfd_symbols(struct dso * dso,const char * debugfile)1589 int dso__load_bfd_symbols(struct dso *dso, const char *debugfile)
1590 {
1591 	int err = -1;
1592 	long symbols_size, symbols_count, i;
1593 	asection *section;
1594 	asymbol **symbols, *sym;
1595 	struct symbol *symbol;
1596 	bfd *abfd;
1597 	u64 start, len;
1598 
1599 	abfd = bfd_openr(debugfile, NULL);
1600 	if (!abfd)
1601 		return -1;
1602 
1603 	if (!bfd_check_format(abfd, bfd_object)) {
1604 		pr_debug2("%s: cannot read %s bfd file.\n", __func__,
1605 			  dso->long_name);
1606 		goto out_close;
1607 	}
1608 
1609 	if (bfd_get_flavour(abfd) == bfd_target_elf_flavour)
1610 		goto out_close;
1611 
1612 	symbols_size = bfd_get_symtab_upper_bound(abfd);
1613 	if (symbols_size == 0) {
1614 		bfd_close(abfd);
1615 		return 0;
1616 	}
1617 
1618 	if (symbols_size < 0)
1619 		goto out_close;
1620 
1621 	symbols = malloc(symbols_size);
1622 	if (!symbols)
1623 		goto out_close;
1624 
1625 	symbols_count = bfd_canonicalize_symtab(abfd, symbols);
1626 	if (symbols_count < 0)
1627 		goto out_free;
1628 
1629 	section = bfd_get_section_by_name(abfd, ".text");
1630 	if (section) {
1631 		for (i = 0; i < symbols_count; ++i) {
1632 			if (!strcmp(bfd_asymbol_name(symbols[i]), "__ImageBase") ||
1633 			    !strcmp(bfd_asymbol_name(symbols[i]), "__image_base__"))
1634 				break;
1635 		}
1636 		if (i < symbols_count) {
1637 			/* PE symbols can only have 4 bytes, so use .text high bits */
1638 			dso->text_offset = section->vma - (u32)section->vma;
1639 			dso->text_offset += (u32)bfd_asymbol_value(symbols[i]);
1640 		} else {
1641 			dso->text_offset = section->vma - section->filepos;
1642 		}
1643 	}
1644 
1645 	qsort(symbols, symbols_count, sizeof(asymbol *), bfd_symbols__cmpvalue);
1646 
1647 #ifdef bfd_get_section
1648 #define bfd_asymbol_section bfd_get_section
1649 #endif
1650 	for (i = 0; i < symbols_count; ++i) {
1651 		sym = symbols[i];
1652 		section = bfd_asymbol_section(sym);
1653 		if (bfd2elf_binding(sym) < 0)
1654 			continue;
1655 
1656 		while (i + 1 < symbols_count &&
1657 		       bfd_asymbol_section(symbols[i + 1]) == section &&
1658 		       bfd2elf_binding(symbols[i + 1]) < 0)
1659 			i++;
1660 
1661 		if (i + 1 < symbols_count &&
1662 		    bfd_asymbol_section(symbols[i + 1]) == section)
1663 			len = symbols[i + 1]->value - sym->value;
1664 		else
1665 			len = section->size - sym->value;
1666 
1667 		start = bfd_asymbol_value(sym) - dso->text_offset;
1668 		symbol = symbol__new(start, len, bfd2elf_binding(sym), STT_FUNC,
1669 				     bfd_asymbol_name(sym));
1670 		if (!symbol)
1671 			goto out_free;
1672 
1673 		symbols__insert(&dso->symbols, symbol);
1674 	}
1675 #ifdef bfd_get_section
1676 #undef bfd_asymbol_section
1677 #endif
1678 
1679 	symbols__fixup_end(&dso->symbols, false);
1680 	symbols__fixup_duplicate(&dso->symbols);
1681 	dso->adjust_symbols = 1;
1682 
1683 	err = 0;
1684 out_free:
1685 	free(symbols);
1686 out_close:
1687 	bfd_close(abfd);
1688 	return err;
1689 }
1690 #endif
1691 
dso__is_compatible_symtab_type(struct dso * dso,bool kmod,enum dso_binary_type type)1692 static bool dso__is_compatible_symtab_type(struct dso *dso, bool kmod,
1693 					   enum dso_binary_type type)
1694 {
1695 	switch (type) {
1696 	case DSO_BINARY_TYPE__JAVA_JIT:
1697 	case DSO_BINARY_TYPE__DEBUGLINK:
1698 	case DSO_BINARY_TYPE__SYSTEM_PATH_DSO:
1699 	case DSO_BINARY_TYPE__FEDORA_DEBUGINFO:
1700 	case DSO_BINARY_TYPE__UBUNTU_DEBUGINFO:
1701 	case DSO_BINARY_TYPE__MIXEDUP_UBUNTU_DEBUGINFO:
1702 	case DSO_BINARY_TYPE__BUILDID_DEBUGINFO:
1703 	case DSO_BINARY_TYPE__OPENEMBEDDED_DEBUGINFO:
1704 		return !kmod && dso->kernel == DSO_SPACE__USER;
1705 
1706 	case DSO_BINARY_TYPE__KALLSYMS:
1707 	case DSO_BINARY_TYPE__VMLINUX:
1708 	case DSO_BINARY_TYPE__KCORE:
1709 		return dso->kernel == DSO_SPACE__KERNEL;
1710 
1711 	case DSO_BINARY_TYPE__GUEST_KALLSYMS:
1712 	case DSO_BINARY_TYPE__GUEST_VMLINUX:
1713 	case DSO_BINARY_TYPE__GUEST_KCORE:
1714 		return dso->kernel == DSO_SPACE__KERNEL_GUEST;
1715 
1716 	case DSO_BINARY_TYPE__GUEST_KMODULE:
1717 	case DSO_BINARY_TYPE__GUEST_KMODULE_COMP:
1718 	case DSO_BINARY_TYPE__SYSTEM_PATH_KMODULE:
1719 	case DSO_BINARY_TYPE__SYSTEM_PATH_KMODULE_COMP:
1720 		/*
1721 		 * kernel modules know their symtab type - it's set when
1722 		 * creating a module dso in machine__addnew_module_map().
1723 		 */
1724 		return kmod && dso->symtab_type == type;
1725 
1726 	case DSO_BINARY_TYPE__BUILD_ID_CACHE:
1727 	case DSO_BINARY_TYPE__BUILD_ID_CACHE_DEBUGINFO:
1728 		return true;
1729 
1730 	case DSO_BINARY_TYPE__BPF_PROG_INFO:
1731 	case DSO_BINARY_TYPE__BPF_IMAGE:
1732 	case DSO_BINARY_TYPE__OOL:
1733 	case DSO_BINARY_TYPE__NOT_FOUND:
1734 	default:
1735 		return false;
1736 	}
1737 }
1738 
1739 /* Checks for the existence of the perf-<pid>.map file in two different
1740  * locations.  First, if the process is a separate mount namespace, check in
1741  * that namespace using the pid of the innermost pid namespace.  If's not in a
1742  * namespace, or the file can't be found there, try in the mount namespace of
1743  * the tracing process using our view of its pid.
1744  */
dso__find_perf_map(char * filebuf,size_t bufsz,struct nsinfo ** nsip)1745 static int dso__find_perf_map(char *filebuf, size_t bufsz,
1746 			      struct nsinfo **nsip)
1747 {
1748 	struct nscookie nsc;
1749 	struct nsinfo *nsi;
1750 	struct nsinfo *nnsi;
1751 	int rc = -1;
1752 
1753 	nsi = *nsip;
1754 
1755 	if (nsinfo__need_setns(nsi)) {
1756 		snprintf(filebuf, bufsz, "/tmp/perf-%d.map", nsinfo__nstgid(nsi));
1757 		nsinfo__mountns_enter(nsi, &nsc);
1758 		rc = access(filebuf, R_OK);
1759 		nsinfo__mountns_exit(&nsc);
1760 		if (rc == 0)
1761 			return rc;
1762 	}
1763 
1764 	nnsi = nsinfo__copy(nsi);
1765 	if (nnsi) {
1766 		nsinfo__put(nsi);
1767 
1768 		nsinfo__clear_need_setns(nnsi);
1769 		snprintf(filebuf, bufsz, "/tmp/perf-%d.map", nsinfo__tgid(nnsi));
1770 		*nsip = nnsi;
1771 		rc = 0;
1772 	}
1773 
1774 	return rc;
1775 }
1776 
dso__load(struct dso * dso,struct map * map)1777 int dso__load(struct dso *dso, struct map *map)
1778 {
1779 	char *name;
1780 	int ret = -1;
1781 	u_int i;
1782 	struct machine *machine = NULL;
1783 	char *root_dir = (char *) "";
1784 	int ss_pos = 0;
1785 	struct symsrc ss_[2];
1786 	struct symsrc *syms_ss = NULL, *runtime_ss = NULL;
1787 	bool kmod;
1788 	bool perfmap;
1789 	struct build_id bid;
1790 	struct nscookie nsc;
1791 	char newmapname[PATH_MAX];
1792 	const char *map_path = dso->long_name;
1793 
1794 	perfmap = strncmp(dso->name, "/tmp/perf-", 10) == 0;
1795 	if (perfmap) {
1796 		if (dso->nsinfo && (dso__find_perf_map(newmapname,
1797 		    sizeof(newmapname), &dso->nsinfo) == 0)) {
1798 			map_path = newmapname;
1799 		}
1800 	}
1801 
1802 	nsinfo__mountns_enter(dso->nsinfo, &nsc);
1803 	pthread_mutex_lock(&dso->lock);
1804 
1805 	/* check again under the dso->lock */
1806 	if (dso__loaded(dso)) {
1807 		ret = 1;
1808 		goto out;
1809 	}
1810 
1811 	kmod = dso->symtab_type == DSO_BINARY_TYPE__SYSTEM_PATH_KMODULE ||
1812 		dso->symtab_type == DSO_BINARY_TYPE__SYSTEM_PATH_KMODULE_COMP ||
1813 		dso->symtab_type == DSO_BINARY_TYPE__GUEST_KMODULE ||
1814 		dso->symtab_type == DSO_BINARY_TYPE__GUEST_KMODULE_COMP;
1815 
1816 	if (dso->kernel && !kmod) {
1817 		if (dso->kernel == DSO_SPACE__KERNEL)
1818 			ret = dso__load_kernel_sym(dso, map);
1819 		else if (dso->kernel == DSO_SPACE__KERNEL_GUEST)
1820 			ret = dso__load_guest_kernel_sym(dso, map);
1821 
1822 		machine = map__kmaps(map)->machine;
1823 		if (machine__is(machine, "x86_64"))
1824 			machine__map_x86_64_entry_trampolines(machine, dso);
1825 		goto out;
1826 	}
1827 
1828 	dso->adjust_symbols = 0;
1829 
1830 	if (perfmap) {
1831 		ret = dso__load_perf_map(map_path, dso);
1832 		dso->symtab_type = ret > 0 ? DSO_BINARY_TYPE__JAVA_JIT :
1833 					     DSO_BINARY_TYPE__NOT_FOUND;
1834 		goto out;
1835 	}
1836 
1837 	if (machine)
1838 		root_dir = machine->root_dir;
1839 
1840 	name = malloc(PATH_MAX);
1841 	if (!name)
1842 		goto out;
1843 
1844 	/*
1845 	 * Read the build id if possible. This is required for
1846 	 * DSO_BINARY_TYPE__BUILDID_DEBUGINFO to work
1847 	 */
1848 	if (!dso->has_build_id &&
1849 	    is_regular_file(dso->long_name)) {
1850 	    __symbol__join_symfs(name, PATH_MAX, dso->long_name);
1851 		if (filename__read_build_id(name, &bid) > 0)
1852 			dso__set_build_id(dso, &bid);
1853 	}
1854 
1855 	/*
1856 	 * Iterate over candidate debug images.
1857 	 * Keep track of "interesting" ones (those which have a symtab, dynsym,
1858 	 * and/or opd section) for processing.
1859 	 */
1860 	for (i = 0; i < DSO_BINARY_TYPE__SYMTAB_CNT; i++) {
1861 		struct symsrc *ss = &ss_[ss_pos];
1862 		bool next_slot = false;
1863 		bool is_reg;
1864 		bool nsexit;
1865 		int bfdrc = -1;
1866 		int sirc = -1;
1867 
1868 		enum dso_binary_type symtab_type = binary_type_symtab[i];
1869 
1870 		nsexit = (symtab_type == DSO_BINARY_TYPE__BUILD_ID_CACHE ||
1871 		    symtab_type == DSO_BINARY_TYPE__BUILD_ID_CACHE_DEBUGINFO);
1872 
1873 		if (!dso__is_compatible_symtab_type(dso, kmod, symtab_type))
1874 			continue;
1875 
1876 		if (dso__read_binary_type_filename(dso, symtab_type,
1877 						   root_dir, name, PATH_MAX))
1878 			continue;
1879 
1880 		if (nsexit)
1881 			nsinfo__mountns_exit(&nsc);
1882 
1883 		is_reg = is_regular_file(name);
1884 		if (!is_reg && errno == ENOENT && dso->nsinfo) {
1885 			char *new_name = filename_with_chroot(dso->nsinfo->pid,
1886 							      name);
1887 			if (new_name) {
1888 				is_reg = is_regular_file(new_name);
1889 				strlcpy(name, new_name, PATH_MAX);
1890 				free(new_name);
1891 			}
1892 		}
1893 
1894 #ifdef HAVE_LIBBFD_SUPPORT
1895 		if (is_reg)
1896 			bfdrc = dso__load_bfd_symbols(dso, name);
1897 #endif
1898 		if (is_reg && bfdrc < 0)
1899 			sirc = symsrc__init(ss, dso, name, symtab_type);
1900 
1901 		if (nsexit)
1902 			nsinfo__mountns_enter(dso->nsinfo, &nsc);
1903 
1904 		if (bfdrc == 0) {
1905 			ret = 0;
1906 			break;
1907 		}
1908 
1909 		if (!is_reg || sirc < 0)
1910 			continue;
1911 
1912 		if (!syms_ss && symsrc__has_symtab(ss)) {
1913 			syms_ss = ss;
1914 			next_slot = true;
1915 			if (!dso->symsrc_filename)
1916 				dso->symsrc_filename = strdup(name);
1917 		}
1918 
1919 		if (!runtime_ss && symsrc__possibly_runtime(ss)) {
1920 			runtime_ss = ss;
1921 			next_slot = true;
1922 		}
1923 
1924 		if (next_slot) {
1925 			ss_pos++;
1926 
1927 			if (syms_ss && runtime_ss)
1928 				break;
1929 		} else {
1930 			symsrc__destroy(ss);
1931 		}
1932 
1933 	}
1934 
1935 	if (!runtime_ss && !syms_ss)
1936 		goto out_free;
1937 
1938 	if (runtime_ss && !syms_ss) {
1939 		syms_ss = runtime_ss;
1940 	}
1941 
1942 	/* We'll have to hope for the best */
1943 	if (!runtime_ss && syms_ss)
1944 		runtime_ss = syms_ss;
1945 
1946 	if (syms_ss)
1947 		ret = dso__load_sym(dso, map, syms_ss, runtime_ss, kmod);
1948 	else
1949 		ret = -1;
1950 
1951 	if (ret > 0) {
1952 		int nr_plt;
1953 
1954 		nr_plt = dso__synthesize_plt_symbols(dso, runtime_ss);
1955 		if (nr_plt > 0)
1956 			ret += nr_plt;
1957 	}
1958 
1959 	for (; ss_pos > 0; ss_pos--)
1960 		symsrc__destroy(&ss_[ss_pos - 1]);
1961 out_free:
1962 	free(name);
1963 	if (ret < 0 && strstr(dso->name, " (deleted)") != NULL)
1964 		ret = 0;
1965 out:
1966 	dso__set_loaded(dso);
1967 	pthread_mutex_unlock(&dso->lock);
1968 	nsinfo__mountns_exit(&nsc);
1969 
1970 	return ret;
1971 }
1972 
map__strcmp(const void * a,const void * b)1973 static int map__strcmp(const void *a, const void *b)
1974 {
1975 	const struct map *ma = *(const struct map **)a, *mb = *(const struct map **)b;
1976 	return strcmp(ma->dso->short_name, mb->dso->short_name);
1977 }
1978 
map__strcmp_name(const void * name,const void * b)1979 static int map__strcmp_name(const void *name, const void *b)
1980 {
1981 	const struct map *map = *(const struct map **)b;
1982 	return strcmp(name, map->dso->short_name);
1983 }
1984 
__maps__sort_by_name(struct maps * maps)1985 void __maps__sort_by_name(struct maps *maps)
1986 {
1987 	qsort(maps->maps_by_name, maps->nr_maps, sizeof(struct map *), map__strcmp);
1988 }
1989 
map__groups__sort_by_name_from_rbtree(struct maps * maps)1990 static int map__groups__sort_by_name_from_rbtree(struct maps *maps)
1991 {
1992 	struct map *map;
1993 	struct map **maps_by_name = realloc(maps->maps_by_name, maps->nr_maps * sizeof(map));
1994 	int i = 0;
1995 
1996 	if (maps_by_name == NULL)
1997 		return -1;
1998 
1999 	maps->maps_by_name = maps_by_name;
2000 	maps->nr_maps_allocated = maps->nr_maps;
2001 
2002 	maps__for_each_entry(maps, map)
2003 		maps_by_name[i++] = map;
2004 
2005 	__maps__sort_by_name(maps);
2006 	return 0;
2007 }
2008 
__maps__find_by_name(struct maps * maps,const char * name)2009 static struct map *__maps__find_by_name(struct maps *maps, const char *name)
2010 {
2011 	struct map **mapp;
2012 
2013 	if (maps->maps_by_name == NULL &&
2014 	    map__groups__sort_by_name_from_rbtree(maps))
2015 		return NULL;
2016 
2017 	mapp = bsearch(name, maps->maps_by_name, maps->nr_maps, sizeof(*mapp), map__strcmp_name);
2018 	if (mapp)
2019 		return *mapp;
2020 	return NULL;
2021 }
2022 
maps__find_by_name(struct maps * maps,const char * name)2023 struct map *maps__find_by_name(struct maps *maps, const char *name)
2024 {
2025 	struct map *map;
2026 
2027 	down_read(&maps->lock);
2028 
2029 	if (maps->last_search_by_name && strcmp(maps->last_search_by_name->dso->short_name, name) == 0) {
2030 		map = maps->last_search_by_name;
2031 		goto out_unlock;
2032 	}
2033 	/*
2034 	 * If we have maps->maps_by_name, then the name isn't in the rbtree,
2035 	 * as maps->maps_by_name mirrors the rbtree when lookups by name are
2036 	 * made.
2037 	 */
2038 	map = __maps__find_by_name(maps, name);
2039 	if (map || maps->maps_by_name != NULL)
2040 		goto out_unlock;
2041 
2042 	/* Fallback to traversing the rbtree... */
2043 	maps__for_each_entry(maps, map)
2044 		if (strcmp(map->dso->short_name, name) == 0) {
2045 			maps->last_search_by_name = map;
2046 			goto out_unlock;
2047 		}
2048 
2049 	map = NULL;
2050 
2051 out_unlock:
2052 	up_read(&maps->lock);
2053 	return map;
2054 }
2055 
dso__load_vmlinux(struct dso * dso,struct map * map,const char * vmlinux,bool vmlinux_allocated)2056 int dso__load_vmlinux(struct dso *dso, struct map *map,
2057 		      const char *vmlinux, bool vmlinux_allocated)
2058 {
2059 	int err = -1;
2060 	struct symsrc ss;
2061 	char symfs_vmlinux[PATH_MAX];
2062 	enum dso_binary_type symtab_type;
2063 
2064 	if (vmlinux[0] == '/')
2065 		snprintf(symfs_vmlinux, sizeof(symfs_vmlinux), "%s", vmlinux);
2066 	else
2067 		symbol__join_symfs(symfs_vmlinux, vmlinux);
2068 
2069 	if (dso->kernel == DSO_SPACE__KERNEL_GUEST)
2070 		symtab_type = DSO_BINARY_TYPE__GUEST_VMLINUX;
2071 	else
2072 		symtab_type = DSO_BINARY_TYPE__VMLINUX;
2073 
2074 	if (symsrc__init(&ss, dso, symfs_vmlinux, symtab_type))
2075 		return -1;
2076 
2077 	err = dso__load_sym(dso, map, &ss, &ss, 0);
2078 	symsrc__destroy(&ss);
2079 
2080 	if (err > 0) {
2081 		if (dso->kernel == DSO_SPACE__KERNEL_GUEST)
2082 			dso->binary_type = DSO_BINARY_TYPE__GUEST_VMLINUX;
2083 		else
2084 			dso->binary_type = DSO_BINARY_TYPE__VMLINUX;
2085 		dso__set_long_name(dso, vmlinux, vmlinux_allocated);
2086 		dso__set_loaded(dso);
2087 		pr_debug("Using %s for symbols\n", symfs_vmlinux);
2088 	}
2089 
2090 	return err;
2091 }
2092 
dso__load_vmlinux_path(struct dso * dso,struct map * map)2093 int dso__load_vmlinux_path(struct dso *dso, struct map *map)
2094 {
2095 	int i, err = 0;
2096 	char *filename = NULL;
2097 
2098 	pr_debug("Looking at the vmlinux_path (%d entries long)\n",
2099 		 vmlinux_path__nr_entries + 1);
2100 
2101 	for (i = 0; i < vmlinux_path__nr_entries; ++i) {
2102 		err = dso__load_vmlinux(dso, map, vmlinux_path[i], false);
2103 		if (err > 0)
2104 			goto out;
2105 	}
2106 
2107 	if (!symbol_conf.ignore_vmlinux_buildid)
2108 		filename = dso__build_id_filename(dso, NULL, 0, false);
2109 	if (filename != NULL) {
2110 		err = dso__load_vmlinux(dso, map, filename, true);
2111 		if (err > 0)
2112 			goto out;
2113 		free(filename);
2114 	}
2115 out:
2116 	return err;
2117 }
2118 
visible_dir_filter(const char * name,struct dirent * d)2119 static bool visible_dir_filter(const char *name, struct dirent *d)
2120 {
2121 	if (d->d_type != DT_DIR)
2122 		return false;
2123 	return lsdir_no_dot_filter(name, d);
2124 }
2125 
find_matching_kcore(struct map * map,char * dir,size_t dir_sz)2126 static int find_matching_kcore(struct map *map, char *dir, size_t dir_sz)
2127 {
2128 	char kallsyms_filename[PATH_MAX];
2129 	int ret = -1;
2130 	struct strlist *dirs;
2131 	struct str_node *nd;
2132 
2133 	dirs = lsdir(dir, visible_dir_filter);
2134 	if (!dirs)
2135 		return -1;
2136 
2137 	strlist__for_each_entry(nd, dirs) {
2138 		scnprintf(kallsyms_filename, sizeof(kallsyms_filename),
2139 			  "%s/%s/kallsyms", dir, nd->s);
2140 		if (!validate_kcore_addresses(kallsyms_filename, map)) {
2141 			strlcpy(dir, kallsyms_filename, dir_sz);
2142 			ret = 0;
2143 			break;
2144 		}
2145 	}
2146 
2147 	strlist__delete(dirs);
2148 
2149 	return ret;
2150 }
2151 
2152 /*
2153  * Use open(O_RDONLY) to check readability directly instead of access(R_OK)
2154  * since access(R_OK) only checks with real UID/GID but open() use effective
2155  * UID/GID and actual capabilities (e.g. /proc/kcore requires CAP_SYS_RAWIO).
2156  */
filename__readable(const char * file)2157 static bool filename__readable(const char *file)
2158 {
2159 	int fd = open(file, O_RDONLY);
2160 	if (fd < 0)
2161 		return false;
2162 	close(fd);
2163 	return true;
2164 }
2165 
dso__find_kallsyms(struct dso * dso,struct map * map)2166 static char *dso__find_kallsyms(struct dso *dso, struct map *map)
2167 {
2168 	struct build_id bid;
2169 	char sbuild_id[SBUILD_ID_SIZE];
2170 	bool is_host = false;
2171 	char path[PATH_MAX];
2172 
2173 	if (!dso->has_build_id) {
2174 		/*
2175 		 * Last resort, if we don't have a build-id and couldn't find
2176 		 * any vmlinux file, try the running kernel kallsyms table.
2177 		 */
2178 		goto proc_kallsyms;
2179 	}
2180 
2181 	if (sysfs__read_build_id("/sys/kernel/notes", &bid) == 0)
2182 		is_host = dso__build_id_equal(dso, &bid);
2183 
2184 	/* Try a fast path for /proc/kallsyms if possible */
2185 	if (is_host) {
2186 		/*
2187 		 * Do not check the build-id cache, unless we know we cannot use
2188 		 * /proc/kcore or module maps don't match to /proc/kallsyms.
2189 		 * To check readability of /proc/kcore, do not use access(R_OK)
2190 		 * since /proc/kcore requires CAP_SYS_RAWIO to read and access
2191 		 * can't check it.
2192 		 */
2193 		if (filename__readable("/proc/kcore") &&
2194 		    !validate_kcore_addresses("/proc/kallsyms", map))
2195 			goto proc_kallsyms;
2196 	}
2197 
2198 	build_id__sprintf(&dso->bid, sbuild_id);
2199 
2200 	/* Find kallsyms in build-id cache with kcore */
2201 	scnprintf(path, sizeof(path), "%s/%s/%s",
2202 		  buildid_dir, DSO__NAME_KCORE, sbuild_id);
2203 
2204 	if (!find_matching_kcore(map, path, sizeof(path)))
2205 		return strdup(path);
2206 
2207 	/* Use current /proc/kallsyms if possible */
2208 	if (is_host) {
2209 proc_kallsyms:
2210 		return strdup("/proc/kallsyms");
2211 	}
2212 
2213 	/* Finally, find a cache of kallsyms */
2214 	if (!build_id_cache__kallsyms_path(sbuild_id, path, sizeof(path))) {
2215 		pr_err("No kallsyms or vmlinux with build-id %s was found\n",
2216 		       sbuild_id);
2217 		return NULL;
2218 	}
2219 
2220 	return strdup(path);
2221 }
2222 
dso__load_kernel_sym(struct dso * dso,struct map * map)2223 static int dso__load_kernel_sym(struct dso *dso, struct map *map)
2224 {
2225 	int err;
2226 	const char *kallsyms_filename = NULL;
2227 	char *kallsyms_allocated_filename = NULL;
2228 	char *filename = NULL;
2229 
2230 	/*
2231 	 * Step 1: if the user specified a kallsyms or vmlinux filename, use
2232 	 * it and only it, reporting errors to the user if it cannot be used.
2233 	 *
2234 	 * For instance, try to analyse an ARM perf.data file _without_ a
2235 	 * build-id, or if the user specifies the wrong path to the right
2236 	 * vmlinux file, obviously we can't fallback to another vmlinux (a
2237 	 * x86_86 one, on the machine where analysis is being performed, say),
2238 	 * or worse, /proc/kallsyms.
2239 	 *
2240 	 * If the specified file _has_ a build-id and there is a build-id
2241 	 * section in the perf.data file, we will still do the expected
2242 	 * validation in dso__load_vmlinux and will bail out if they don't
2243 	 * match.
2244 	 */
2245 	if (symbol_conf.kallsyms_name != NULL) {
2246 		kallsyms_filename = symbol_conf.kallsyms_name;
2247 		goto do_kallsyms;
2248 	}
2249 
2250 	if (!symbol_conf.ignore_vmlinux && symbol_conf.vmlinux_name != NULL) {
2251 		return dso__load_vmlinux(dso, map, symbol_conf.vmlinux_name, false);
2252 	}
2253 
2254 	/*
2255 	 * Before checking on common vmlinux locations, check if it's
2256 	 * stored as standard build id binary (not kallsyms) under
2257 	 * .debug cache.
2258 	 */
2259 	if (!symbol_conf.ignore_vmlinux_buildid)
2260 		filename = __dso__build_id_filename(dso, NULL, 0, false, false);
2261 	if (filename != NULL) {
2262 		err = dso__load_vmlinux(dso, map, filename, true);
2263 		if (err > 0)
2264 			return err;
2265 		free(filename);
2266 	}
2267 
2268 	if (!symbol_conf.ignore_vmlinux && vmlinux_path != NULL) {
2269 		err = dso__load_vmlinux_path(dso, map);
2270 		if (err > 0)
2271 			return err;
2272 	}
2273 
2274 	/* do not try local files if a symfs was given */
2275 	if (symbol_conf.symfs[0] != 0)
2276 		return -1;
2277 
2278 	kallsyms_allocated_filename = dso__find_kallsyms(dso, map);
2279 	if (!kallsyms_allocated_filename)
2280 		return -1;
2281 
2282 	kallsyms_filename = kallsyms_allocated_filename;
2283 
2284 do_kallsyms:
2285 	err = dso__load_kallsyms(dso, kallsyms_filename, map);
2286 	if (err > 0)
2287 		pr_debug("Using %s for symbols\n", kallsyms_filename);
2288 	free(kallsyms_allocated_filename);
2289 
2290 	if (err > 0 && !dso__is_kcore(dso)) {
2291 		dso->binary_type = DSO_BINARY_TYPE__KALLSYMS;
2292 		dso__set_long_name(dso, DSO__NAME_KALLSYMS, false);
2293 		map__fixup_start(map);
2294 		map__fixup_end(map);
2295 	}
2296 
2297 	return err;
2298 }
2299 
dso__load_guest_kernel_sym(struct dso * dso,struct map * map)2300 static int dso__load_guest_kernel_sym(struct dso *dso, struct map *map)
2301 {
2302 	int err;
2303 	const char *kallsyms_filename = NULL;
2304 	struct machine *machine = map__kmaps(map)->machine;
2305 	char path[PATH_MAX];
2306 
2307 	if (machine__is_default_guest(machine)) {
2308 		/*
2309 		 * if the user specified a vmlinux filename, use it and only
2310 		 * it, reporting errors to the user if it cannot be used.
2311 		 * Or use file guest_kallsyms inputted by user on commandline
2312 		 */
2313 		if (symbol_conf.default_guest_vmlinux_name != NULL) {
2314 			err = dso__load_vmlinux(dso, map,
2315 						symbol_conf.default_guest_vmlinux_name,
2316 						false);
2317 			return err;
2318 		}
2319 
2320 		kallsyms_filename = symbol_conf.default_guest_kallsyms;
2321 		if (!kallsyms_filename)
2322 			return -1;
2323 	} else {
2324 		sprintf(path, "%s/proc/kallsyms", machine->root_dir);
2325 		kallsyms_filename = path;
2326 	}
2327 
2328 	err = dso__load_kallsyms(dso, kallsyms_filename, map);
2329 	if (err > 0)
2330 		pr_debug("Using %s for symbols\n", kallsyms_filename);
2331 	if (err > 0 && !dso__is_kcore(dso)) {
2332 		dso->binary_type = DSO_BINARY_TYPE__GUEST_KALLSYMS;
2333 		dso__set_long_name(dso, machine->mmap_name, false);
2334 		map__fixup_start(map);
2335 		map__fixup_end(map);
2336 	}
2337 
2338 	return err;
2339 }
2340 
vmlinux_path__exit(void)2341 static void vmlinux_path__exit(void)
2342 {
2343 	while (--vmlinux_path__nr_entries >= 0)
2344 		zfree(&vmlinux_path[vmlinux_path__nr_entries]);
2345 	vmlinux_path__nr_entries = 0;
2346 
2347 	zfree(&vmlinux_path);
2348 }
2349 
2350 static const char * const vmlinux_paths[] = {
2351 	"vmlinux",
2352 	"/boot/vmlinux"
2353 };
2354 
2355 static const char * const vmlinux_paths_upd[] = {
2356 	"/boot/vmlinux-%s",
2357 	"/usr/lib/debug/boot/vmlinux-%s",
2358 	"/lib/modules/%s/build/vmlinux",
2359 	"/usr/lib/debug/lib/modules/%s/vmlinux",
2360 	"/usr/lib/debug/boot/vmlinux-%s.debug"
2361 };
2362 
vmlinux_path__add(const char * new_entry)2363 static int vmlinux_path__add(const char *new_entry)
2364 {
2365 	vmlinux_path[vmlinux_path__nr_entries] = strdup(new_entry);
2366 	if (vmlinux_path[vmlinux_path__nr_entries] == NULL)
2367 		return -1;
2368 	++vmlinux_path__nr_entries;
2369 
2370 	return 0;
2371 }
2372 
vmlinux_path__init(struct perf_env * env)2373 static int vmlinux_path__init(struct perf_env *env)
2374 {
2375 	struct utsname uts;
2376 	char bf[PATH_MAX];
2377 	char *kernel_version;
2378 	unsigned int i;
2379 
2380 	vmlinux_path = malloc(sizeof(char *) * (ARRAY_SIZE(vmlinux_paths) +
2381 			      ARRAY_SIZE(vmlinux_paths_upd)));
2382 	if (vmlinux_path == NULL)
2383 		return -1;
2384 
2385 	for (i = 0; i < ARRAY_SIZE(vmlinux_paths); i++)
2386 		if (vmlinux_path__add(vmlinux_paths[i]) < 0)
2387 			goto out_fail;
2388 
2389 	/* only try kernel version if no symfs was given */
2390 	if (symbol_conf.symfs[0] != 0)
2391 		return 0;
2392 
2393 	if (env) {
2394 		kernel_version = env->os_release;
2395 	} else {
2396 		if (uname(&uts) < 0)
2397 			goto out_fail;
2398 
2399 		kernel_version = uts.release;
2400 	}
2401 
2402 	for (i = 0; i < ARRAY_SIZE(vmlinux_paths_upd); i++) {
2403 		snprintf(bf, sizeof(bf), vmlinux_paths_upd[i], kernel_version);
2404 		if (vmlinux_path__add(bf) < 0)
2405 			goto out_fail;
2406 	}
2407 
2408 	return 0;
2409 
2410 out_fail:
2411 	vmlinux_path__exit();
2412 	return -1;
2413 }
2414 
setup_list(struct strlist ** list,const char * list_str,const char * list_name)2415 int setup_list(struct strlist **list, const char *list_str,
2416 		      const char *list_name)
2417 {
2418 	if (list_str == NULL)
2419 		return 0;
2420 
2421 	*list = strlist__new(list_str, NULL);
2422 	if (!*list) {
2423 		pr_err("problems parsing %s list\n", list_name);
2424 		return -1;
2425 	}
2426 
2427 	symbol_conf.has_filter = true;
2428 	return 0;
2429 }
2430 
setup_intlist(struct intlist ** list,const char * list_str,const char * list_name)2431 int setup_intlist(struct intlist **list, const char *list_str,
2432 		  const char *list_name)
2433 {
2434 	if (list_str == NULL)
2435 		return 0;
2436 
2437 	*list = intlist__new(list_str);
2438 	if (!*list) {
2439 		pr_err("problems parsing %s list\n", list_name);
2440 		return -1;
2441 	}
2442 	return 0;
2443 }
2444 
setup_addrlist(struct intlist ** addr_list,struct strlist * sym_list)2445 static int setup_addrlist(struct intlist **addr_list, struct strlist *sym_list)
2446 {
2447 	struct str_node *pos, *tmp;
2448 	unsigned long val;
2449 	char *sep;
2450 	const char *end;
2451 	int i = 0, err;
2452 
2453 	*addr_list = intlist__new(NULL);
2454 	if (!*addr_list)
2455 		return -1;
2456 
2457 	strlist__for_each_entry_safe(pos, tmp, sym_list) {
2458 		errno = 0;
2459 		val = strtoul(pos->s, &sep, 16);
2460 		if (errno || (sep == pos->s))
2461 			continue;
2462 
2463 		if (*sep != '\0') {
2464 			end = pos->s + strlen(pos->s) - 1;
2465 			while (end >= sep && isspace(*end))
2466 				end--;
2467 
2468 			if (end >= sep)
2469 				continue;
2470 		}
2471 
2472 		err = intlist__add(*addr_list, val);
2473 		if (err)
2474 			break;
2475 
2476 		strlist__remove(sym_list, pos);
2477 		i++;
2478 	}
2479 
2480 	if (i == 0) {
2481 		intlist__delete(*addr_list);
2482 		*addr_list = NULL;
2483 	}
2484 
2485 	return 0;
2486 }
2487 
symbol__read_kptr_restrict(void)2488 static bool symbol__read_kptr_restrict(void)
2489 {
2490 	bool value = false;
2491 	FILE *fp = fopen("/proc/sys/kernel/kptr_restrict", "r");
2492 
2493 	if (fp != NULL) {
2494 		char line[8];
2495 
2496 		if (fgets(line, sizeof(line), fp) != NULL)
2497 			value = perf_cap__capable(CAP_SYSLOG) ?
2498 					(atoi(line) >= 2) :
2499 					(atoi(line) != 0);
2500 
2501 		fclose(fp);
2502 	}
2503 
2504 	/* Per kernel/kallsyms.c:
2505 	 * we also restrict when perf_event_paranoid > 1 w/o CAP_SYSLOG
2506 	 */
2507 	if (perf_event_paranoid() > 1 && !perf_cap__capable(CAP_SYSLOG))
2508 		value = true;
2509 
2510 	return value;
2511 }
2512 
symbol__annotation_init(void)2513 int symbol__annotation_init(void)
2514 {
2515 	if (symbol_conf.init_annotation)
2516 		return 0;
2517 
2518 	if (symbol_conf.initialized) {
2519 		pr_err("Annotation needs to be init before symbol__init()\n");
2520 		return -1;
2521 	}
2522 
2523 	symbol_conf.priv_size += sizeof(struct annotation);
2524 	symbol_conf.init_annotation = true;
2525 	return 0;
2526 }
2527 
symbol__init(struct perf_env * env)2528 int symbol__init(struct perf_env *env)
2529 {
2530 	const char *symfs;
2531 
2532 	if (symbol_conf.initialized)
2533 		return 0;
2534 
2535 	symbol_conf.priv_size = PERF_ALIGN(symbol_conf.priv_size, sizeof(u64));
2536 
2537 	symbol__elf_init();
2538 
2539 	if (symbol_conf.sort_by_name)
2540 		symbol_conf.priv_size += (sizeof(struct symbol_name_rb_node) -
2541 					  sizeof(struct symbol));
2542 
2543 	if (symbol_conf.try_vmlinux_path && vmlinux_path__init(env) < 0)
2544 		return -1;
2545 
2546 	if (symbol_conf.field_sep && *symbol_conf.field_sep == '.') {
2547 		pr_err("'.' is the only non valid --field-separator argument\n");
2548 		return -1;
2549 	}
2550 
2551 	if (setup_list(&symbol_conf.dso_list,
2552 		       symbol_conf.dso_list_str, "dso") < 0)
2553 		return -1;
2554 
2555 	if (setup_list(&symbol_conf.comm_list,
2556 		       symbol_conf.comm_list_str, "comm") < 0)
2557 		goto out_free_dso_list;
2558 
2559 	if (setup_intlist(&symbol_conf.pid_list,
2560 		       symbol_conf.pid_list_str, "pid") < 0)
2561 		goto out_free_comm_list;
2562 
2563 	if (setup_intlist(&symbol_conf.tid_list,
2564 		       symbol_conf.tid_list_str, "tid") < 0)
2565 		goto out_free_pid_list;
2566 
2567 	if (setup_list(&symbol_conf.sym_list,
2568 		       symbol_conf.sym_list_str, "symbol") < 0)
2569 		goto out_free_tid_list;
2570 
2571 	if (symbol_conf.sym_list &&
2572 	    setup_addrlist(&symbol_conf.addr_list, symbol_conf.sym_list) < 0)
2573 		goto out_free_sym_list;
2574 
2575 	if (setup_list(&symbol_conf.bt_stop_list,
2576 		       symbol_conf.bt_stop_list_str, "symbol") < 0)
2577 		goto out_free_sym_list;
2578 
2579 	/*
2580 	 * A path to symbols of "/" is identical to ""
2581 	 * reset here for simplicity.
2582 	 */
2583 	symfs = realpath(symbol_conf.symfs, NULL);
2584 	if (symfs == NULL)
2585 		symfs = symbol_conf.symfs;
2586 	if (strcmp(symfs, "/") == 0)
2587 		symbol_conf.symfs = "";
2588 	if (symfs != symbol_conf.symfs)
2589 		free((void *)symfs);
2590 
2591 	symbol_conf.kptr_restrict = symbol__read_kptr_restrict();
2592 
2593 	symbol_conf.initialized = true;
2594 	return 0;
2595 
2596 out_free_sym_list:
2597 	strlist__delete(symbol_conf.sym_list);
2598 	intlist__delete(symbol_conf.addr_list);
2599 out_free_tid_list:
2600 	intlist__delete(symbol_conf.tid_list);
2601 out_free_pid_list:
2602 	intlist__delete(symbol_conf.pid_list);
2603 out_free_comm_list:
2604 	strlist__delete(symbol_conf.comm_list);
2605 out_free_dso_list:
2606 	strlist__delete(symbol_conf.dso_list);
2607 	return -1;
2608 }
2609 
symbol__exit(void)2610 void symbol__exit(void)
2611 {
2612 	if (!symbol_conf.initialized)
2613 		return;
2614 	strlist__delete(symbol_conf.bt_stop_list);
2615 	strlist__delete(symbol_conf.sym_list);
2616 	strlist__delete(symbol_conf.dso_list);
2617 	strlist__delete(symbol_conf.comm_list);
2618 	intlist__delete(symbol_conf.tid_list);
2619 	intlist__delete(symbol_conf.pid_list);
2620 	intlist__delete(symbol_conf.addr_list);
2621 	vmlinux_path__exit();
2622 	symbol_conf.sym_list = symbol_conf.dso_list = symbol_conf.comm_list = NULL;
2623 	symbol_conf.bt_stop_list = NULL;
2624 	symbol_conf.initialized = false;
2625 }
2626 
symbol__config_symfs(const struct option * opt __maybe_unused,const char * dir,int unset __maybe_unused)2627 int symbol__config_symfs(const struct option *opt __maybe_unused,
2628 			 const char *dir, int unset __maybe_unused)
2629 {
2630 	char *bf = NULL;
2631 	int ret;
2632 
2633 	symbol_conf.symfs = strdup(dir);
2634 	if (symbol_conf.symfs == NULL)
2635 		return -ENOMEM;
2636 
2637 	/* skip the locally configured cache if a symfs is given, and
2638 	 * config buildid dir to symfs/.debug
2639 	 */
2640 	ret = asprintf(&bf, "%s/%s", dir, ".debug");
2641 	if (ret < 0)
2642 		return -ENOMEM;
2643 
2644 	set_buildid_dir(bf);
2645 
2646 	free(bf);
2647 	return 0;
2648 }
2649 
mem_info__get(struct mem_info * mi)2650 struct mem_info *mem_info__get(struct mem_info *mi)
2651 {
2652 	if (mi)
2653 		refcount_inc(&mi->refcnt);
2654 	return mi;
2655 }
2656 
mem_info__put(struct mem_info * mi)2657 void mem_info__put(struct mem_info *mi)
2658 {
2659 	if (mi && refcount_dec_and_test(&mi->refcnt))
2660 		free(mi);
2661 }
2662 
mem_info__new(void)2663 struct mem_info *mem_info__new(void)
2664 {
2665 	struct mem_info *mi = zalloc(sizeof(*mi));
2666 
2667 	if (mi)
2668 		refcount_set(&mi->refcnt, 1);
2669 	return mi;
2670 }
2671 
2672 /*
2673  * Checks that user supplied symbol kernel files are accessible because
2674  * the default mechanism for accessing elf files fails silently. i.e. if
2675  * debug syms for a build ID aren't found perf carries on normally. When
2676  * they are user supplied we should assume that the user doesn't want to
2677  * silently fail.
2678  */
symbol__validate_sym_arguments(void)2679 int symbol__validate_sym_arguments(void)
2680 {
2681 	if (symbol_conf.vmlinux_name &&
2682 	    access(symbol_conf.vmlinux_name, R_OK)) {
2683 		pr_err("Invalid file: %s\n", symbol_conf.vmlinux_name);
2684 		return -EINVAL;
2685 	}
2686 	if (symbol_conf.kallsyms_name &&
2687 	    access(symbol_conf.kallsyms_name, R_OK)) {
2688 		pr_err("Invalid file: %s\n", symbol_conf.kallsyms_name);
2689 		return -EINVAL;
2690 	}
2691 	return 0;
2692 }
2693