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