xref: /openbmc/linux/tools/perf/util/map.c (revision 2f8be0e5)
1 // SPDX-License-Identifier: GPL-2.0
2 #include "symbol.h"
3 #include <assert.h>
4 #include <errno.h>
5 #include <inttypes.h>
6 #include <limits.h>
7 #include <stdlib.h>
8 #include <string.h>
9 #include <stdio.h>
10 #include <unistd.h>
11 #include <uapi/linux/mman.h> /* To get things like MAP_HUGETLB even on older libc headers */
12 #include "dso.h"
13 #include "map.h"
14 #include "map_symbol.h"
15 #include "thread.h"
16 #include "vdso.h"
17 #include "build-id.h"
18 #include "debug.h"
19 #include "machine.h"
20 #include <linux/string.h>
21 #include <linux/zalloc.h>
22 #include "srcline.h"
23 #include "namespaces.h"
24 #include "unwind.h"
25 #include "srccode.h"
26 #include "ui/ui.h"
27 
28 static void __maps__insert(struct maps *maps, struct map *map);
29 
30 static inline int is_anon_memory(const char *filename, u32 flags)
31 {
32 	return flags & MAP_HUGETLB ||
33 	       !strcmp(filename, "//anon") ||
34 	       !strncmp(filename, "/dev/zero", sizeof("/dev/zero") - 1) ||
35 	       !strncmp(filename, "/anon_hugepage", sizeof("/anon_hugepage") - 1);
36 }
37 
38 static inline int is_no_dso_memory(const char *filename)
39 {
40 	return !strncmp(filename, "[stack", 6) ||
41 	       !strncmp(filename, "/SYSV",5)   ||
42 	       !strcmp(filename, "[heap]");
43 }
44 
45 static inline int is_android_lib(const char *filename)
46 {
47 	return strstarts(filename, "/data/app-lib/") ||
48 	       strstarts(filename, "/system/lib/");
49 }
50 
51 static inline bool replace_android_lib(const char *filename, char *newfilename)
52 {
53 	const char *libname;
54 	char *app_abi;
55 	size_t app_abi_length, new_length;
56 	size_t lib_length = 0;
57 
58 	libname  = strrchr(filename, '/');
59 	if (libname)
60 		lib_length = strlen(libname);
61 
62 	app_abi = getenv("APP_ABI");
63 	if (!app_abi)
64 		return false;
65 
66 	app_abi_length = strlen(app_abi);
67 
68 	if (strstarts(filename, "/data/app-lib/")) {
69 		char *apk_path;
70 
71 		if (!app_abi_length)
72 			return false;
73 
74 		new_length = 7 + app_abi_length + lib_length;
75 
76 		apk_path = getenv("APK_PATH");
77 		if (apk_path) {
78 			new_length += strlen(apk_path) + 1;
79 			if (new_length > PATH_MAX)
80 				return false;
81 			snprintf(newfilename, new_length,
82 				 "%s/libs/%s/%s", apk_path, app_abi, libname);
83 		} else {
84 			if (new_length > PATH_MAX)
85 				return false;
86 			snprintf(newfilename, new_length,
87 				 "libs/%s/%s", app_abi, libname);
88 		}
89 		return true;
90 	}
91 
92 	if (strstarts(filename, "/system/lib/")) {
93 		char *ndk, *app;
94 		const char *arch;
95 		size_t ndk_length;
96 		size_t app_length;
97 
98 		ndk = getenv("NDK_ROOT");
99 		app = getenv("APP_PLATFORM");
100 
101 		if (!(ndk && app))
102 			return false;
103 
104 		ndk_length = strlen(ndk);
105 		app_length = strlen(app);
106 
107 		if (!(ndk_length && app_length && app_abi_length))
108 			return false;
109 
110 		arch = !strncmp(app_abi, "arm", 3) ? "arm" :
111 		       !strncmp(app_abi, "mips", 4) ? "mips" :
112 		       !strncmp(app_abi, "x86", 3) ? "x86" : NULL;
113 
114 		if (!arch)
115 			return false;
116 
117 		new_length = 27 + ndk_length +
118 			     app_length + lib_length
119 			   + strlen(arch);
120 
121 		if (new_length > PATH_MAX)
122 			return false;
123 		snprintf(newfilename, new_length,
124 			"%s/platforms/%s/arch-%s/usr/lib/%s",
125 			ndk, app, arch, libname);
126 
127 		return true;
128 	}
129 	return false;
130 }
131 
132 void map__init(struct map *map, u64 start, u64 end, u64 pgoff, struct dso *dso)
133 {
134 	map->start    = start;
135 	map->end      = end;
136 	map->pgoff    = pgoff;
137 	map->reloc    = 0;
138 	map->dso      = dso__get(dso);
139 	map->map_ip   = map__map_ip;
140 	map->unmap_ip = map__unmap_ip;
141 	RB_CLEAR_NODE(&map->rb_node);
142 	map->erange_warned = false;
143 	refcount_set(&map->refcnt, 1);
144 }
145 
146 struct map *map__new(struct machine *machine, u64 start, u64 len,
147 		     u64 pgoff, struct dso_id *id,
148 		     u32 prot, u32 flags, char *filename,
149 		     struct thread *thread)
150 {
151 	struct map *map = malloc(sizeof(*map));
152 	struct nsinfo *nsi = NULL;
153 	struct nsinfo *nnsi;
154 
155 	if (map != NULL) {
156 		char newfilename[PATH_MAX];
157 		struct dso *dso;
158 		int anon, no_dso, vdso, android;
159 
160 		android = is_android_lib(filename);
161 		anon = is_anon_memory(filename, flags);
162 		vdso = is_vdso_map(filename);
163 		no_dso = is_no_dso_memory(filename);
164 		map->prot = prot;
165 		map->flags = flags;
166 		nsi = nsinfo__get(thread->nsinfo);
167 
168 		if ((anon || no_dso) && nsi && (prot & PROT_EXEC)) {
169 			snprintf(newfilename, sizeof(newfilename),
170 				 "/tmp/perf-%d.map", nsi->pid);
171 			filename = newfilename;
172 		}
173 
174 		if (android) {
175 			if (replace_android_lib(filename, newfilename))
176 				filename = newfilename;
177 		}
178 
179 		if (vdso) {
180 			/* The vdso maps are always on the host and not the
181 			 * container.  Ensure that we don't use setns to look
182 			 * them up.
183 			 */
184 			nnsi = nsinfo__copy(nsi);
185 			if (nnsi) {
186 				nsinfo__put(nsi);
187 				nnsi->need_setns = false;
188 				nsi = nnsi;
189 			}
190 			pgoff = 0;
191 			dso = machine__findnew_vdso(machine, thread);
192 		} else
193 			dso = machine__findnew_dso_id(machine, filename, id);
194 
195 		if (dso == NULL)
196 			goto out_delete;
197 
198 		map__init(map, start, start + len, pgoff, dso);
199 
200 		if (anon || no_dso) {
201 			map->map_ip = map->unmap_ip = identity__map_ip;
202 
203 			/*
204 			 * Set memory without DSO as loaded. All map__find_*
205 			 * functions still return NULL, and we avoid the
206 			 * unnecessary map__load warning.
207 			 */
208 			if (!(prot & PROT_EXEC))
209 				dso__set_loaded(dso);
210 		}
211 		dso->nsinfo = nsi;
212 		dso__put(dso);
213 	}
214 	return map;
215 out_delete:
216 	nsinfo__put(nsi);
217 	free(map);
218 	return NULL;
219 }
220 
221 /*
222  * Constructor variant for modules (where we know from /proc/modules where
223  * they are loaded) and for vmlinux, where only after we load all the
224  * symbols we'll know where it starts and ends.
225  */
226 struct map *map__new2(u64 start, struct dso *dso)
227 {
228 	struct map *map = calloc(1, (sizeof(*map) +
229 				     (dso->kernel ? sizeof(struct kmap) : 0)));
230 	if (map != NULL) {
231 		/*
232 		 * ->end will be filled after we load all the symbols
233 		 */
234 		map__init(map, start, 0, 0, dso);
235 	}
236 
237 	return map;
238 }
239 
240 bool __map__is_kernel(const struct map *map)
241 {
242 	if (!map->dso->kernel)
243 		return false;
244 	return machine__kernel_map(map__kmaps((struct map *)map)->machine) == map;
245 }
246 
247 bool __map__is_extra_kernel_map(const struct map *map)
248 {
249 	struct kmap *kmap = __map__kmap((struct map *)map);
250 
251 	return kmap && kmap->name[0];
252 }
253 
254 bool __map__is_bpf_prog(const struct map *map)
255 {
256 	const char *name;
257 
258 	if (map->dso->binary_type == DSO_BINARY_TYPE__BPF_PROG_INFO)
259 		return true;
260 
261 	/*
262 	 * If PERF_RECORD_BPF_EVENT is not included, the dso will not have
263 	 * type of DSO_BINARY_TYPE__BPF_PROG_INFO. In such cases, we can
264 	 * guess the type based on name.
265 	 */
266 	name = map->dso->short_name;
267 	return name && (strstr(name, "bpf_prog_") == name);
268 }
269 
270 bool __map__is_bpf_image(const struct map *map)
271 {
272 	const char *name;
273 
274 	if (map->dso->binary_type == DSO_BINARY_TYPE__BPF_IMAGE)
275 		return true;
276 
277 	/*
278 	 * If PERF_RECORD_KSYMBOL is not included, the dso will not have
279 	 * type of DSO_BINARY_TYPE__BPF_IMAGE. In such cases, we can
280 	 * guess the type based on name.
281 	 */
282 	name = map->dso->short_name;
283 	return name && is_bpf_image(name);
284 }
285 
286 bool __map__is_ool(const struct map *map)
287 {
288 	return map->dso && map->dso->binary_type == DSO_BINARY_TYPE__OOL;
289 }
290 
291 bool map__has_symbols(const struct map *map)
292 {
293 	return dso__has_symbols(map->dso);
294 }
295 
296 static void map__exit(struct map *map)
297 {
298 	BUG_ON(refcount_read(&map->refcnt) != 0);
299 	dso__zput(map->dso);
300 }
301 
302 void map__delete(struct map *map)
303 {
304 	map__exit(map);
305 	free(map);
306 }
307 
308 void map__put(struct map *map)
309 {
310 	if (map && refcount_dec_and_test(&map->refcnt))
311 		map__delete(map);
312 }
313 
314 void map__fixup_start(struct map *map)
315 {
316 	struct rb_root_cached *symbols = &map->dso->symbols;
317 	struct rb_node *nd = rb_first_cached(symbols);
318 	if (nd != NULL) {
319 		struct symbol *sym = rb_entry(nd, struct symbol, rb_node);
320 		map->start = sym->start;
321 	}
322 }
323 
324 void map__fixup_end(struct map *map)
325 {
326 	struct rb_root_cached *symbols = &map->dso->symbols;
327 	struct rb_node *nd = rb_last(&symbols->rb_root);
328 	if (nd != NULL) {
329 		struct symbol *sym = rb_entry(nd, struct symbol, rb_node);
330 		map->end = sym->end;
331 	}
332 }
333 
334 #define DSO__DELETED "(deleted)"
335 
336 int map__load(struct map *map)
337 {
338 	const char *name = map->dso->long_name;
339 	int nr;
340 
341 	if (dso__loaded(map->dso))
342 		return 0;
343 
344 	nr = dso__load(map->dso, map);
345 	if (nr < 0) {
346 		if (map->dso->has_build_id) {
347 			char sbuild_id[SBUILD_ID_SIZE];
348 
349 			build_id__sprintf(map->dso->build_id,
350 					  sizeof(map->dso->build_id),
351 					  sbuild_id);
352 			pr_debug("%s with build id %s not found", name, sbuild_id);
353 		} else
354 			pr_debug("Failed to open %s", name);
355 
356 		pr_debug(", continuing without symbols\n");
357 		return -1;
358 	} else if (nr == 0) {
359 #ifdef HAVE_LIBELF_SUPPORT
360 		const size_t len = strlen(name);
361 		const size_t real_len = len - sizeof(DSO__DELETED);
362 
363 		if (len > sizeof(DSO__DELETED) &&
364 		    strcmp(name + real_len + 1, DSO__DELETED) == 0) {
365 			pr_debug("%.*s was updated (is prelink enabled?). "
366 				"Restart the long running apps that use it!\n",
367 				   (int)real_len, name);
368 		} else {
369 			pr_debug("no symbols found in %s, maybe install a debug package?\n", name);
370 		}
371 #endif
372 		return -1;
373 	}
374 
375 	return 0;
376 }
377 
378 struct symbol *map__find_symbol(struct map *map, u64 addr)
379 {
380 	if (map__load(map) < 0)
381 		return NULL;
382 
383 	return dso__find_symbol(map->dso, addr);
384 }
385 
386 struct symbol *map__find_symbol_by_name(struct map *map, const char *name)
387 {
388 	if (map__load(map) < 0)
389 		return NULL;
390 
391 	if (!dso__sorted_by_name(map->dso))
392 		dso__sort_by_name(map->dso);
393 
394 	return dso__find_symbol_by_name(map->dso, name);
395 }
396 
397 struct map *map__clone(struct map *from)
398 {
399 	size_t size = sizeof(struct map);
400 	struct map *map;
401 
402 	if (from->dso && from->dso->kernel)
403 		size += sizeof(struct kmap);
404 
405 	map = memdup(from, size);
406 	if (map != NULL) {
407 		refcount_set(&map->refcnt, 1);
408 		RB_CLEAR_NODE(&map->rb_node);
409 		dso__get(map->dso);
410 	}
411 
412 	return map;
413 }
414 
415 size_t map__fprintf(struct map *map, FILE *fp)
416 {
417 	return fprintf(fp, " %" PRIx64 "-%" PRIx64 " %" PRIx64 " %s\n",
418 		       map->start, map->end, map->pgoff, map->dso->name);
419 }
420 
421 size_t map__fprintf_dsoname(struct map *map, FILE *fp)
422 {
423 	char buf[symbol_conf.pad_output_len_dso + 1];
424 	const char *dsoname = "[unknown]";
425 
426 	if (map && map->dso) {
427 		if (symbol_conf.show_kernel_path && map->dso->long_name)
428 			dsoname = map->dso->long_name;
429 		else
430 			dsoname = map->dso->name;
431 	}
432 
433 	if (symbol_conf.pad_output_len_dso) {
434 		scnprintf_pad(buf, symbol_conf.pad_output_len_dso, "%s", dsoname);
435 		dsoname = buf;
436 	}
437 
438 	return fprintf(fp, "%s", dsoname);
439 }
440 
441 char *map__srcline(struct map *map, u64 addr, struct symbol *sym)
442 {
443 	if (map == NULL)
444 		return SRCLINE_UNKNOWN;
445 	return get_srcline(map->dso, map__rip_2objdump(map, addr), sym, true, true, addr);
446 }
447 
448 int map__fprintf_srcline(struct map *map, u64 addr, const char *prefix,
449 			 FILE *fp)
450 {
451 	int ret = 0;
452 
453 	if (map && map->dso) {
454 		char *srcline = map__srcline(map, addr, NULL);
455 		if (strncmp(srcline, SRCLINE_UNKNOWN, strlen(SRCLINE_UNKNOWN)) != 0)
456 			ret = fprintf(fp, "%s%s", prefix, srcline);
457 		free_srcline(srcline);
458 	}
459 	return ret;
460 }
461 
462 void srccode_state_free(struct srccode_state *state)
463 {
464 	zfree(&state->srcfile);
465 	state->line = 0;
466 }
467 
468 /**
469  * map__rip_2objdump - convert symbol start address to objdump address.
470  * @map: memory map
471  * @rip: symbol start address
472  *
473  * objdump wants/reports absolute IPs for ET_EXEC, and RIPs for ET_DYN.
474  * map->dso->adjust_symbols==1 for ET_EXEC-like cases except ET_REL which is
475  * relative to section start.
476  *
477  * Return: Address suitable for passing to "objdump --start-address="
478  */
479 u64 map__rip_2objdump(struct map *map, u64 rip)
480 {
481 	struct kmap *kmap = __map__kmap(map);
482 
483 	/*
484 	 * vmlinux does not have program headers for PTI entry trampolines and
485 	 * kcore may not either. However the trampoline object code is on the
486 	 * main kernel map, so just use that instead.
487 	 */
488 	if (kmap && is_entry_trampoline(kmap->name) && kmap->kmaps && kmap->kmaps->machine) {
489 		struct map *kernel_map = machine__kernel_map(kmap->kmaps->machine);
490 
491 		if (kernel_map)
492 			map = kernel_map;
493 	}
494 
495 	if (!map->dso->adjust_symbols)
496 		return rip;
497 
498 	if (map->dso->rel)
499 		return rip - map->pgoff;
500 
501 	/*
502 	 * kernel modules also have DSO_TYPE_USER in dso->kernel,
503 	 * but all kernel modules are ET_REL, so won't get here.
504 	 */
505 	if (map->dso->kernel == DSO_SPACE__USER)
506 		return rip + map->dso->text_offset;
507 
508 	return map->unmap_ip(map, rip) - map->reloc;
509 }
510 
511 /**
512  * map__objdump_2mem - convert objdump address to a memory address.
513  * @map: memory map
514  * @ip: objdump address
515  *
516  * Closely related to map__rip_2objdump(), this function takes an address from
517  * objdump and converts it to a memory address.  Note this assumes that @map
518  * contains the address.  To be sure the result is valid, check it forwards
519  * e.g. map__rip_2objdump(map->map_ip(map, map__objdump_2mem(map, ip))) == ip
520  *
521  * Return: Memory address.
522  */
523 u64 map__objdump_2mem(struct map *map, u64 ip)
524 {
525 	if (!map->dso->adjust_symbols)
526 		return map->unmap_ip(map, ip);
527 
528 	if (map->dso->rel)
529 		return map->unmap_ip(map, ip + map->pgoff);
530 
531 	/*
532 	 * kernel modules also have DSO_TYPE_USER in dso->kernel,
533 	 * but all kernel modules are ET_REL, so won't get here.
534 	 */
535 	if (map->dso->kernel == DSO_SPACE__USER)
536 		return map->unmap_ip(map, ip - map->dso->text_offset);
537 
538 	return ip + map->reloc;
539 }
540 
541 void maps__init(struct maps *maps, struct machine *machine)
542 {
543 	maps->entries = RB_ROOT;
544 	init_rwsem(&maps->lock);
545 	maps->machine = machine;
546 	maps->last_search_by_name = NULL;
547 	maps->nr_maps = 0;
548 	maps->maps_by_name = NULL;
549 	refcount_set(&maps->refcnt, 1);
550 }
551 
552 static void __maps__free_maps_by_name(struct maps *maps)
553 {
554 	/*
555 	 * Free everything to try to do it from the rbtree in the next search
556 	 */
557 	zfree(&maps->maps_by_name);
558 	maps->nr_maps_allocated = 0;
559 }
560 
561 void maps__insert(struct maps *maps, struct map *map)
562 {
563 	down_write(&maps->lock);
564 	__maps__insert(maps, map);
565 	++maps->nr_maps;
566 
567 	if (map->dso && map->dso->kernel) {
568 		struct kmap *kmap = map__kmap(map);
569 
570 		if (kmap)
571 			kmap->kmaps = maps;
572 		else
573 			pr_err("Internal error: kernel dso with non kernel map\n");
574 	}
575 
576 
577 	/*
578 	 * If we already performed some search by name, then we need to add the just
579 	 * inserted map and resort.
580 	 */
581 	if (maps->maps_by_name) {
582 		if (maps->nr_maps > maps->nr_maps_allocated) {
583 			int nr_allocate = maps->nr_maps * 2;
584 			struct map **maps_by_name = realloc(maps->maps_by_name, nr_allocate * sizeof(map));
585 
586 			if (maps_by_name == NULL) {
587 				__maps__free_maps_by_name(maps);
588 				up_write(&maps->lock);
589 				return;
590 			}
591 
592 			maps->maps_by_name = maps_by_name;
593 			maps->nr_maps_allocated = nr_allocate;
594 		}
595 		maps->maps_by_name[maps->nr_maps - 1] = map;
596 		__maps__sort_by_name(maps);
597 	}
598 	up_write(&maps->lock);
599 }
600 
601 static void __maps__remove(struct maps *maps, struct map *map)
602 {
603 	rb_erase_init(&map->rb_node, &maps->entries);
604 	map__put(map);
605 }
606 
607 void maps__remove(struct maps *maps, struct map *map)
608 {
609 	down_write(&maps->lock);
610 	if (maps->last_search_by_name == map)
611 		maps->last_search_by_name = NULL;
612 
613 	__maps__remove(maps, map);
614 	--maps->nr_maps;
615 	if (maps->maps_by_name)
616 		__maps__free_maps_by_name(maps);
617 	up_write(&maps->lock);
618 }
619 
620 static void __maps__purge(struct maps *maps)
621 {
622 	struct map *pos, *next;
623 
624 	maps__for_each_entry_safe(maps, pos, next) {
625 		rb_erase_init(&pos->rb_node,  &maps->entries);
626 		map__put(pos);
627 	}
628 }
629 
630 void maps__exit(struct maps *maps)
631 {
632 	down_write(&maps->lock);
633 	__maps__purge(maps);
634 	up_write(&maps->lock);
635 }
636 
637 bool maps__empty(struct maps *maps)
638 {
639 	return !maps__first(maps);
640 }
641 
642 struct maps *maps__new(struct machine *machine)
643 {
644 	struct maps *maps = zalloc(sizeof(*maps));
645 
646 	if (maps != NULL)
647 		maps__init(maps, machine);
648 
649 	return maps;
650 }
651 
652 void maps__delete(struct maps *maps)
653 {
654 	maps__exit(maps);
655 	unwind__finish_access(maps);
656 	free(maps);
657 }
658 
659 void maps__put(struct maps *maps)
660 {
661 	if (maps && refcount_dec_and_test(&maps->refcnt))
662 		maps__delete(maps);
663 }
664 
665 struct symbol *maps__find_symbol(struct maps *maps, u64 addr, struct map **mapp)
666 {
667 	struct map *map = maps__find(maps, addr);
668 
669 	/* Ensure map is loaded before using map->map_ip */
670 	if (map != NULL && map__load(map) >= 0) {
671 		if (mapp != NULL)
672 			*mapp = map;
673 		return map__find_symbol(map, map->map_ip(map, addr));
674 	}
675 
676 	return NULL;
677 }
678 
679 static bool map__contains_symbol(struct map *map, struct symbol *sym)
680 {
681 	u64 ip = map->unmap_ip(map, sym->start);
682 
683 	return ip >= map->start && ip < map->end;
684 }
685 
686 struct symbol *maps__find_symbol_by_name(struct maps *maps, const char *name, struct map **mapp)
687 {
688 	struct symbol *sym;
689 	struct map *pos;
690 
691 	down_read(&maps->lock);
692 
693 	maps__for_each_entry(maps, pos) {
694 		sym = map__find_symbol_by_name(pos, name);
695 
696 		if (sym == NULL)
697 			continue;
698 		if (!map__contains_symbol(pos, sym)) {
699 			sym = NULL;
700 			continue;
701 		}
702 		if (mapp != NULL)
703 			*mapp = pos;
704 		goto out;
705 	}
706 
707 	sym = NULL;
708 out:
709 	up_read(&maps->lock);
710 	return sym;
711 }
712 
713 int maps__find_ams(struct maps *maps, struct addr_map_symbol *ams)
714 {
715 	if (ams->addr < ams->ms.map->start || ams->addr >= ams->ms.map->end) {
716 		if (maps == NULL)
717 			return -1;
718 		ams->ms.map = maps__find(maps, ams->addr);
719 		if (ams->ms.map == NULL)
720 			return -1;
721 	}
722 
723 	ams->al_addr = ams->ms.map->map_ip(ams->ms.map, ams->addr);
724 	ams->ms.sym = map__find_symbol(ams->ms.map, ams->al_addr);
725 
726 	return ams->ms.sym ? 0 : -1;
727 }
728 
729 size_t maps__fprintf(struct maps *maps, FILE *fp)
730 {
731 	size_t printed = 0;
732 	struct map *pos;
733 
734 	down_read(&maps->lock);
735 
736 	maps__for_each_entry(maps, pos) {
737 		printed += fprintf(fp, "Map:");
738 		printed += map__fprintf(pos, fp);
739 		if (verbose > 2) {
740 			printed += dso__fprintf(pos->dso, fp);
741 			printed += fprintf(fp, "--\n");
742 		}
743 	}
744 
745 	up_read(&maps->lock);
746 
747 	return printed;
748 }
749 
750 int maps__fixup_overlappings(struct maps *maps, struct map *map, FILE *fp)
751 {
752 	struct rb_root *root;
753 	struct rb_node *next, *first;
754 	int err = 0;
755 
756 	down_write(&maps->lock);
757 
758 	root = &maps->entries;
759 
760 	/*
761 	 * Find first map where end > map->start.
762 	 * Same as find_vma() in kernel.
763 	 */
764 	next = root->rb_node;
765 	first = NULL;
766 	while (next) {
767 		struct map *pos = rb_entry(next, struct map, rb_node);
768 
769 		if (pos->end > map->start) {
770 			first = next;
771 			if (pos->start <= map->start)
772 				break;
773 			next = next->rb_left;
774 		} else
775 			next = next->rb_right;
776 	}
777 
778 	next = first;
779 	while (next) {
780 		struct map *pos = rb_entry(next, struct map, rb_node);
781 		next = rb_next(&pos->rb_node);
782 
783 		/*
784 		 * Stop if current map starts after map->end.
785 		 * Maps are ordered by start: next will not overlap for sure.
786 		 */
787 		if (pos->start >= map->end)
788 			break;
789 
790 		if (verbose >= 2) {
791 
792 			if (use_browser) {
793 				pr_debug("overlapping maps in %s (disable tui for more info)\n",
794 					   map->dso->name);
795 			} else {
796 				fputs("overlapping maps:\n", fp);
797 				map__fprintf(map, fp);
798 				map__fprintf(pos, fp);
799 			}
800 		}
801 
802 		rb_erase_init(&pos->rb_node, root);
803 		/*
804 		 * Now check if we need to create new maps for areas not
805 		 * overlapped by the new map:
806 		 */
807 		if (map->start > pos->start) {
808 			struct map *before = map__clone(pos);
809 
810 			if (before == NULL) {
811 				err = -ENOMEM;
812 				goto put_map;
813 			}
814 
815 			before->end = map->start;
816 			__maps__insert(maps, before);
817 			if (verbose >= 2 && !use_browser)
818 				map__fprintf(before, fp);
819 			map__put(before);
820 		}
821 
822 		if (map->end < pos->end) {
823 			struct map *after = map__clone(pos);
824 
825 			if (after == NULL) {
826 				err = -ENOMEM;
827 				goto put_map;
828 			}
829 
830 			after->start = map->end;
831 			after->pgoff += map->end - pos->start;
832 			assert(pos->map_ip(pos, map->end) == after->map_ip(after, map->end));
833 			__maps__insert(maps, after);
834 			if (verbose >= 2 && !use_browser)
835 				map__fprintf(after, fp);
836 			map__put(after);
837 		}
838 put_map:
839 		map__put(pos);
840 
841 		if (err)
842 			goto out;
843 	}
844 
845 	err = 0;
846 out:
847 	up_write(&maps->lock);
848 	return err;
849 }
850 
851 /*
852  * XXX This should not really _copy_ te maps, but refcount them.
853  */
854 int maps__clone(struct thread *thread, struct maps *parent)
855 {
856 	struct maps *maps = thread->maps;
857 	int err = -ENOMEM;
858 	struct map *map;
859 
860 	down_read(&parent->lock);
861 
862 	maps__for_each_entry(parent, map) {
863 		struct map *new = map__clone(map);
864 		if (new == NULL)
865 			goto out_unlock;
866 
867 		err = unwind__prepare_access(maps, new, NULL);
868 		if (err)
869 			goto out_unlock;
870 
871 		maps__insert(maps, new);
872 		map__put(new);
873 	}
874 
875 	err = 0;
876 out_unlock:
877 	up_read(&parent->lock);
878 	return err;
879 }
880 
881 static void __maps__insert(struct maps *maps, struct map *map)
882 {
883 	struct rb_node **p = &maps->entries.rb_node;
884 	struct rb_node *parent = NULL;
885 	const u64 ip = map->start;
886 	struct map *m;
887 
888 	while (*p != NULL) {
889 		parent = *p;
890 		m = rb_entry(parent, struct map, rb_node);
891 		if (ip < m->start)
892 			p = &(*p)->rb_left;
893 		else
894 			p = &(*p)->rb_right;
895 	}
896 
897 	rb_link_node(&map->rb_node, parent, p);
898 	rb_insert_color(&map->rb_node, &maps->entries);
899 	map__get(map);
900 }
901 
902 struct map *maps__find(struct maps *maps, u64 ip)
903 {
904 	struct rb_node *p;
905 	struct map *m;
906 
907 	down_read(&maps->lock);
908 
909 	p = maps->entries.rb_node;
910 	while (p != NULL) {
911 		m = rb_entry(p, struct map, rb_node);
912 		if (ip < m->start)
913 			p = p->rb_left;
914 		else if (ip >= m->end)
915 			p = p->rb_right;
916 		else
917 			goto out;
918 	}
919 
920 	m = NULL;
921 out:
922 	up_read(&maps->lock);
923 	return m;
924 }
925 
926 struct map *maps__first(struct maps *maps)
927 {
928 	struct rb_node *first = rb_first(&maps->entries);
929 
930 	if (first)
931 		return rb_entry(first, struct map, rb_node);
932 	return NULL;
933 }
934 
935 static struct map *__map__next(struct map *map)
936 {
937 	struct rb_node *next = rb_next(&map->rb_node);
938 
939 	if (next)
940 		return rb_entry(next, struct map, rb_node);
941 	return NULL;
942 }
943 
944 struct map *map__next(struct map *map)
945 {
946 	return map ? __map__next(map) : NULL;
947 }
948 
949 struct kmap *__map__kmap(struct map *map)
950 {
951 	if (!map->dso || !map->dso->kernel)
952 		return NULL;
953 	return (struct kmap *)(map + 1);
954 }
955 
956 struct kmap *map__kmap(struct map *map)
957 {
958 	struct kmap *kmap = __map__kmap(map);
959 
960 	if (!kmap)
961 		pr_err("Internal error: map__kmap with a non-kernel map\n");
962 	return kmap;
963 }
964 
965 struct maps *map__kmaps(struct map *map)
966 {
967 	struct kmap *kmap = map__kmap(map);
968 
969 	if (!kmap || !kmap->kmaps) {
970 		pr_err("Internal error: map__kmaps with a non-kernel map\n");
971 		return NULL;
972 	}
973 	return kmap->kmaps;
974 }
975