xref: /openbmc/linux/tools/perf/util/map.c (revision 11a163f2)
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_android_lib(const char *filename)
31 {
32 	return strstarts(filename, "/data/app-lib/") ||
33 	       strstarts(filename, "/system/lib/");
34 }
35 
36 static inline bool replace_android_lib(const char *filename, char *newfilename)
37 {
38 	const char *libname;
39 	char *app_abi;
40 	size_t app_abi_length, new_length;
41 	size_t lib_length = 0;
42 
43 	libname  = strrchr(filename, '/');
44 	if (libname)
45 		lib_length = strlen(libname);
46 
47 	app_abi = getenv("APP_ABI");
48 	if (!app_abi)
49 		return false;
50 
51 	app_abi_length = strlen(app_abi);
52 
53 	if (strstarts(filename, "/data/app-lib/")) {
54 		char *apk_path;
55 
56 		if (!app_abi_length)
57 			return false;
58 
59 		new_length = 7 + app_abi_length + lib_length;
60 
61 		apk_path = getenv("APK_PATH");
62 		if (apk_path) {
63 			new_length += strlen(apk_path) + 1;
64 			if (new_length > PATH_MAX)
65 				return false;
66 			snprintf(newfilename, new_length,
67 				 "%s/libs/%s/%s", apk_path, app_abi, libname);
68 		} else {
69 			if (new_length > PATH_MAX)
70 				return false;
71 			snprintf(newfilename, new_length,
72 				 "libs/%s/%s", app_abi, libname);
73 		}
74 		return true;
75 	}
76 
77 	if (strstarts(filename, "/system/lib/")) {
78 		char *ndk, *app;
79 		const char *arch;
80 		size_t ndk_length;
81 		size_t app_length;
82 
83 		ndk = getenv("NDK_ROOT");
84 		app = getenv("APP_PLATFORM");
85 
86 		if (!(ndk && app))
87 			return false;
88 
89 		ndk_length = strlen(ndk);
90 		app_length = strlen(app);
91 
92 		if (!(ndk_length && app_length && app_abi_length))
93 			return false;
94 
95 		arch = !strncmp(app_abi, "arm", 3) ? "arm" :
96 		       !strncmp(app_abi, "mips", 4) ? "mips" :
97 		       !strncmp(app_abi, "x86", 3) ? "x86" : NULL;
98 
99 		if (!arch)
100 			return false;
101 
102 		new_length = 27 + ndk_length +
103 			     app_length + lib_length
104 			   + strlen(arch);
105 
106 		if (new_length > PATH_MAX)
107 			return false;
108 		snprintf(newfilename, new_length,
109 			"%s/platforms/%s/arch-%s/usr/lib/%s",
110 			ndk, app, arch, libname);
111 
112 		return true;
113 	}
114 	return false;
115 }
116 
117 void map__init(struct map *map, u64 start, u64 end, u64 pgoff, struct dso *dso)
118 {
119 	map->start    = start;
120 	map->end      = end;
121 	map->pgoff    = pgoff;
122 	map->reloc    = 0;
123 	map->dso      = dso__get(dso);
124 	map->map_ip   = map__map_ip;
125 	map->unmap_ip = map__unmap_ip;
126 	RB_CLEAR_NODE(&map->rb_node);
127 	map->erange_warned = false;
128 	refcount_set(&map->refcnt, 1);
129 }
130 
131 struct map *map__new(struct machine *machine, u64 start, u64 len,
132 		     u64 pgoff, struct dso_id *id,
133 		     u32 prot, u32 flags, char *filename,
134 		     struct thread *thread)
135 {
136 	struct map *map = malloc(sizeof(*map));
137 	struct nsinfo *nsi = NULL;
138 	struct nsinfo *nnsi;
139 
140 	if (map != NULL) {
141 		char newfilename[PATH_MAX];
142 		struct dso *dso;
143 		int anon, no_dso, vdso, android;
144 
145 		android = is_android_lib(filename);
146 		anon = is_anon_memory(filename) || flags & MAP_HUGETLB;
147 		vdso = is_vdso_map(filename);
148 		no_dso = is_no_dso_memory(filename);
149 		map->prot = prot;
150 		map->flags = flags;
151 		nsi = nsinfo__get(thread->nsinfo);
152 
153 		if ((anon || no_dso) && nsi && (prot & PROT_EXEC)) {
154 			snprintf(newfilename, sizeof(newfilename),
155 				 "/tmp/perf-%d.map", nsi->pid);
156 			filename = newfilename;
157 		}
158 
159 		if (android) {
160 			if (replace_android_lib(filename, newfilename))
161 				filename = newfilename;
162 		}
163 
164 		if (vdso) {
165 			/* The vdso maps are always on the host and not the
166 			 * container.  Ensure that we don't use setns to look
167 			 * them up.
168 			 */
169 			nnsi = nsinfo__copy(nsi);
170 			if (nnsi) {
171 				nsinfo__put(nsi);
172 				nnsi->need_setns = false;
173 				nsi = nnsi;
174 			}
175 			pgoff = 0;
176 			dso = machine__findnew_vdso(machine, thread);
177 		} else
178 			dso = machine__findnew_dso_id(machine, filename, id);
179 
180 		if (dso == NULL)
181 			goto out_delete;
182 
183 		map__init(map, start, start + len, pgoff, dso);
184 
185 		if (anon || no_dso) {
186 			map->map_ip = map->unmap_ip = identity__map_ip;
187 
188 			/*
189 			 * Set memory without DSO as loaded. All map__find_*
190 			 * functions still return NULL, and we avoid the
191 			 * unnecessary map__load warning.
192 			 */
193 			if (!(prot & PROT_EXEC))
194 				dso__set_loaded(dso);
195 		}
196 		dso->nsinfo = nsi;
197 		dso__put(dso);
198 	}
199 	return map;
200 out_delete:
201 	nsinfo__put(nsi);
202 	free(map);
203 	return NULL;
204 }
205 
206 /*
207  * Constructor variant for modules (where we know from /proc/modules where
208  * they are loaded) and for vmlinux, where only after we load all the
209  * symbols we'll know where it starts and ends.
210  */
211 struct map *map__new2(u64 start, struct dso *dso)
212 {
213 	struct map *map = calloc(1, (sizeof(*map) +
214 				     (dso->kernel ? sizeof(struct kmap) : 0)));
215 	if (map != NULL) {
216 		/*
217 		 * ->end will be filled after we load all the symbols
218 		 */
219 		map__init(map, start, 0, 0, dso);
220 	}
221 
222 	return map;
223 }
224 
225 bool __map__is_kernel(const struct map *map)
226 {
227 	if (!map->dso->kernel)
228 		return false;
229 	return machine__kernel_map(map__kmaps((struct map *)map)->machine) == map;
230 }
231 
232 bool __map__is_extra_kernel_map(const struct map *map)
233 {
234 	struct kmap *kmap = __map__kmap((struct map *)map);
235 
236 	return kmap && kmap->name[0];
237 }
238 
239 bool __map__is_bpf_prog(const struct map *map)
240 {
241 	const char *name;
242 
243 	if (map->dso->binary_type == DSO_BINARY_TYPE__BPF_PROG_INFO)
244 		return true;
245 
246 	/*
247 	 * If PERF_RECORD_BPF_EVENT is not included, the dso will not have
248 	 * type of DSO_BINARY_TYPE__BPF_PROG_INFO. In such cases, we can
249 	 * guess the type based on name.
250 	 */
251 	name = map->dso->short_name;
252 	return name && (strstr(name, "bpf_prog_") == name);
253 }
254 
255 bool __map__is_bpf_image(const struct map *map)
256 {
257 	const char *name;
258 
259 	if (map->dso->binary_type == DSO_BINARY_TYPE__BPF_IMAGE)
260 		return true;
261 
262 	/*
263 	 * If PERF_RECORD_KSYMBOL is not included, the dso will not have
264 	 * type of DSO_BINARY_TYPE__BPF_IMAGE. In such cases, we can
265 	 * guess the type based on name.
266 	 */
267 	name = map->dso->short_name;
268 	return name && is_bpf_image(name);
269 }
270 
271 bool __map__is_ool(const struct map *map)
272 {
273 	return map->dso && map->dso->binary_type == DSO_BINARY_TYPE__OOL;
274 }
275 
276 bool map__has_symbols(const struct map *map)
277 {
278 	return dso__has_symbols(map->dso);
279 }
280 
281 static void map__exit(struct map *map)
282 {
283 	BUG_ON(refcount_read(&map->refcnt) != 0);
284 	dso__zput(map->dso);
285 }
286 
287 void map__delete(struct map *map)
288 {
289 	map__exit(map);
290 	free(map);
291 }
292 
293 void map__put(struct map *map)
294 {
295 	if (map && refcount_dec_and_test(&map->refcnt))
296 		map__delete(map);
297 }
298 
299 void map__fixup_start(struct map *map)
300 {
301 	struct rb_root_cached *symbols = &map->dso->symbols;
302 	struct rb_node *nd = rb_first_cached(symbols);
303 	if (nd != NULL) {
304 		struct symbol *sym = rb_entry(nd, struct symbol, rb_node);
305 		map->start = sym->start;
306 	}
307 }
308 
309 void map__fixup_end(struct map *map)
310 {
311 	struct rb_root_cached *symbols = &map->dso->symbols;
312 	struct rb_node *nd = rb_last(&symbols->rb_root);
313 	if (nd != NULL) {
314 		struct symbol *sym = rb_entry(nd, struct symbol, rb_node);
315 		map->end = sym->end;
316 	}
317 }
318 
319 #define DSO__DELETED "(deleted)"
320 
321 int map__load(struct map *map)
322 {
323 	const char *name = map->dso->long_name;
324 	int nr;
325 
326 	if (dso__loaded(map->dso))
327 		return 0;
328 
329 	nr = dso__load(map->dso, map);
330 	if (nr < 0) {
331 		if (map->dso->has_build_id) {
332 			char sbuild_id[SBUILD_ID_SIZE];
333 
334 			build_id__sprintf(&map->dso->bid, sbuild_id);
335 			pr_debug("%s with build id %s not found", name, sbuild_id);
336 		} else
337 			pr_debug("Failed to open %s", name);
338 
339 		pr_debug(", continuing without symbols\n");
340 		return -1;
341 	} else if (nr == 0) {
342 #ifdef HAVE_LIBELF_SUPPORT
343 		const size_t len = strlen(name);
344 		const size_t real_len = len - sizeof(DSO__DELETED);
345 
346 		if (len > sizeof(DSO__DELETED) &&
347 		    strcmp(name + real_len + 1, DSO__DELETED) == 0) {
348 			pr_debug("%.*s was updated (is prelink enabled?). "
349 				"Restart the long running apps that use it!\n",
350 				   (int)real_len, name);
351 		} else {
352 			pr_debug("no symbols found in %s, maybe install a debug package?\n", name);
353 		}
354 #endif
355 		return -1;
356 	}
357 
358 	return 0;
359 }
360 
361 struct symbol *map__find_symbol(struct map *map, u64 addr)
362 {
363 	if (map__load(map) < 0)
364 		return NULL;
365 
366 	return dso__find_symbol(map->dso, addr);
367 }
368 
369 struct symbol *map__find_symbol_by_name(struct map *map, const char *name)
370 {
371 	if (map__load(map) < 0)
372 		return NULL;
373 
374 	if (!dso__sorted_by_name(map->dso))
375 		dso__sort_by_name(map->dso);
376 
377 	return dso__find_symbol_by_name(map->dso, name);
378 }
379 
380 struct map *map__clone(struct map *from)
381 {
382 	size_t size = sizeof(struct map);
383 	struct map *map;
384 
385 	if (from->dso && from->dso->kernel)
386 		size += sizeof(struct kmap);
387 
388 	map = memdup(from, size);
389 	if (map != NULL) {
390 		refcount_set(&map->refcnt, 1);
391 		RB_CLEAR_NODE(&map->rb_node);
392 		dso__get(map->dso);
393 	}
394 
395 	return map;
396 }
397 
398 size_t map__fprintf(struct map *map, FILE *fp)
399 {
400 	return fprintf(fp, " %" PRIx64 "-%" PRIx64 " %" PRIx64 " %s\n",
401 		       map->start, map->end, map->pgoff, map->dso->name);
402 }
403 
404 size_t map__fprintf_dsoname(struct map *map, FILE *fp)
405 {
406 	char buf[symbol_conf.pad_output_len_dso + 1];
407 	const char *dsoname = "[unknown]";
408 
409 	if (map && map->dso) {
410 		if (symbol_conf.show_kernel_path && map->dso->long_name)
411 			dsoname = map->dso->long_name;
412 		else
413 			dsoname = map->dso->name;
414 	}
415 
416 	if (symbol_conf.pad_output_len_dso) {
417 		scnprintf_pad(buf, symbol_conf.pad_output_len_dso, "%s", dsoname);
418 		dsoname = buf;
419 	}
420 
421 	return fprintf(fp, "%s", dsoname);
422 }
423 
424 char *map__srcline(struct map *map, u64 addr, struct symbol *sym)
425 {
426 	if (map == NULL)
427 		return SRCLINE_UNKNOWN;
428 	return get_srcline(map->dso, map__rip_2objdump(map, addr), sym, true, true, addr);
429 }
430 
431 int map__fprintf_srcline(struct map *map, u64 addr, const char *prefix,
432 			 FILE *fp)
433 {
434 	int ret = 0;
435 
436 	if (map && map->dso) {
437 		char *srcline = map__srcline(map, addr, NULL);
438 		if (strncmp(srcline, SRCLINE_UNKNOWN, strlen(SRCLINE_UNKNOWN)) != 0)
439 			ret = fprintf(fp, "%s%s", prefix, srcline);
440 		free_srcline(srcline);
441 	}
442 	return ret;
443 }
444 
445 void srccode_state_free(struct srccode_state *state)
446 {
447 	zfree(&state->srcfile);
448 	state->line = 0;
449 }
450 
451 /**
452  * map__rip_2objdump - convert symbol start address to objdump address.
453  * @map: memory map
454  * @rip: symbol start address
455  *
456  * objdump wants/reports absolute IPs for ET_EXEC, and RIPs for ET_DYN.
457  * map->dso->adjust_symbols==1 for ET_EXEC-like cases except ET_REL which is
458  * relative to section start.
459  *
460  * Return: Address suitable for passing to "objdump --start-address="
461  */
462 u64 map__rip_2objdump(struct map *map, u64 rip)
463 {
464 	struct kmap *kmap = __map__kmap(map);
465 
466 	/*
467 	 * vmlinux does not have program headers for PTI entry trampolines and
468 	 * kcore may not either. However the trampoline object code is on the
469 	 * main kernel map, so just use that instead.
470 	 */
471 	if (kmap && is_entry_trampoline(kmap->name) && kmap->kmaps && kmap->kmaps->machine) {
472 		struct map *kernel_map = machine__kernel_map(kmap->kmaps->machine);
473 
474 		if (kernel_map)
475 			map = kernel_map;
476 	}
477 
478 	if (!map->dso->adjust_symbols)
479 		return rip;
480 
481 	if (map->dso->rel)
482 		return rip - map->pgoff;
483 
484 	/*
485 	 * kernel modules also have DSO_TYPE_USER in dso->kernel,
486 	 * but all kernel modules are ET_REL, so won't get here.
487 	 */
488 	if (map->dso->kernel == DSO_SPACE__USER)
489 		return rip + map->dso->text_offset;
490 
491 	return map->unmap_ip(map, rip) - map->reloc;
492 }
493 
494 /**
495  * map__objdump_2mem - convert objdump address to a memory address.
496  * @map: memory map
497  * @ip: objdump address
498  *
499  * Closely related to map__rip_2objdump(), this function takes an address from
500  * objdump and converts it to a memory address.  Note this assumes that @map
501  * contains the address.  To be sure the result is valid, check it forwards
502  * e.g. map__rip_2objdump(map->map_ip(map, map__objdump_2mem(map, ip))) == ip
503  *
504  * Return: Memory address.
505  */
506 u64 map__objdump_2mem(struct map *map, u64 ip)
507 {
508 	if (!map->dso->adjust_symbols)
509 		return map->unmap_ip(map, ip);
510 
511 	if (map->dso->rel)
512 		return map->unmap_ip(map, ip + map->pgoff);
513 
514 	/*
515 	 * kernel modules also have DSO_TYPE_USER in dso->kernel,
516 	 * but all kernel modules are ET_REL, so won't get here.
517 	 */
518 	if (map->dso->kernel == DSO_SPACE__USER)
519 		return map->unmap_ip(map, ip - map->dso->text_offset);
520 
521 	return ip + map->reloc;
522 }
523 
524 void maps__init(struct maps *maps, struct machine *machine)
525 {
526 	maps->entries = RB_ROOT;
527 	init_rwsem(&maps->lock);
528 	maps->machine = machine;
529 	maps->last_search_by_name = NULL;
530 	maps->nr_maps = 0;
531 	maps->maps_by_name = NULL;
532 	refcount_set(&maps->refcnt, 1);
533 }
534 
535 static void __maps__free_maps_by_name(struct maps *maps)
536 {
537 	/*
538 	 * Free everything to try to do it from the rbtree in the next search
539 	 */
540 	zfree(&maps->maps_by_name);
541 	maps->nr_maps_allocated = 0;
542 }
543 
544 void maps__insert(struct maps *maps, struct map *map)
545 {
546 	down_write(&maps->lock);
547 	__maps__insert(maps, map);
548 	++maps->nr_maps;
549 
550 	if (map->dso && map->dso->kernel) {
551 		struct kmap *kmap = map__kmap(map);
552 
553 		if (kmap)
554 			kmap->kmaps = maps;
555 		else
556 			pr_err("Internal error: kernel dso with non kernel map\n");
557 	}
558 
559 
560 	/*
561 	 * If we already performed some search by name, then we need to add the just
562 	 * inserted map and resort.
563 	 */
564 	if (maps->maps_by_name) {
565 		if (maps->nr_maps > maps->nr_maps_allocated) {
566 			int nr_allocate = maps->nr_maps * 2;
567 			struct map **maps_by_name = realloc(maps->maps_by_name, nr_allocate * sizeof(map));
568 
569 			if (maps_by_name == NULL) {
570 				__maps__free_maps_by_name(maps);
571 				up_write(&maps->lock);
572 				return;
573 			}
574 
575 			maps->maps_by_name = maps_by_name;
576 			maps->nr_maps_allocated = nr_allocate;
577 		}
578 		maps->maps_by_name[maps->nr_maps - 1] = map;
579 		__maps__sort_by_name(maps);
580 	}
581 	up_write(&maps->lock);
582 }
583 
584 static void __maps__remove(struct maps *maps, struct map *map)
585 {
586 	rb_erase_init(&map->rb_node, &maps->entries);
587 	map__put(map);
588 }
589 
590 void maps__remove(struct maps *maps, struct map *map)
591 {
592 	down_write(&maps->lock);
593 	if (maps->last_search_by_name == map)
594 		maps->last_search_by_name = NULL;
595 
596 	__maps__remove(maps, map);
597 	--maps->nr_maps;
598 	if (maps->maps_by_name)
599 		__maps__free_maps_by_name(maps);
600 	up_write(&maps->lock);
601 }
602 
603 static void __maps__purge(struct maps *maps)
604 {
605 	struct map *pos, *next;
606 
607 	maps__for_each_entry_safe(maps, pos, next) {
608 		rb_erase_init(&pos->rb_node,  &maps->entries);
609 		map__put(pos);
610 	}
611 }
612 
613 void maps__exit(struct maps *maps)
614 {
615 	down_write(&maps->lock);
616 	__maps__purge(maps);
617 	up_write(&maps->lock);
618 }
619 
620 bool maps__empty(struct maps *maps)
621 {
622 	return !maps__first(maps);
623 }
624 
625 struct maps *maps__new(struct machine *machine)
626 {
627 	struct maps *maps = zalloc(sizeof(*maps));
628 
629 	if (maps != NULL)
630 		maps__init(maps, machine);
631 
632 	return maps;
633 }
634 
635 void maps__delete(struct maps *maps)
636 {
637 	maps__exit(maps);
638 	unwind__finish_access(maps);
639 	free(maps);
640 }
641 
642 void maps__put(struct maps *maps)
643 {
644 	if (maps && refcount_dec_and_test(&maps->refcnt))
645 		maps__delete(maps);
646 }
647 
648 struct symbol *maps__find_symbol(struct maps *maps, u64 addr, struct map **mapp)
649 {
650 	struct map *map = maps__find(maps, addr);
651 
652 	/* Ensure map is loaded before using map->map_ip */
653 	if (map != NULL && map__load(map) >= 0) {
654 		if (mapp != NULL)
655 			*mapp = map;
656 		return map__find_symbol(map, map->map_ip(map, addr));
657 	}
658 
659 	return NULL;
660 }
661 
662 static bool map__contains_symbol(struct map *map, struct symbol *sym)
663 {
664 	u64 ip = map->unmap_ip(map, sym->start);
665 
666 	return ip >= map->start && ip < map->end;
667 }
668 
669 struct symbol *maps__find_symbol_by_name(struct maps *maps, const char *name, struct map **mapp)
670 {
671 	struct symbol *sym;
672 	struct map *pos;
673 
674 	down_read(&maps->lock);
675 
676 	maps__for_each_entry(maps, pos) {
677 		sym = map__find_symbol_by_name(pos, name);
678 
679 		if (sym == NULL)
680 			continue;
681 		if (!map__contains_symbol(pos, sym)) {
682 			sym = NULL;
683 			continue;
684 		}
685 		if (mapp != NULL)
686 			*mapp = pos;
687 		goto out;
688 	}
689 
690 	sym = NULL;
691 out:
692 	up_read(&maps->lock);
693 	return sym;
694 }
695 
696 int maps__find_ams(struct maps *maps, struct addr_map_symbol *ams)
697 {
698 	if (ams->addr < ams->ms.map->start || ams->addr >= ams->ms.map->end) {
699 		if (maps == NULL)
700 			return -1;
701 		ams->ms.map = maps__find(maps, ams->addr);
702 		if (ams->ms.map == NULL)
703 			return -1;
704 	}
705 
706 	ams->al_addr = ams->ms.map->map_ip(ams->ms.map, ams->addr);
707 	ams->ms.sym = map__find_symbol(ams->ms.map, ams->al_addr);
708 
709 	return ams->ms.sym ? 0 : -1;
710 }
711 
712 size_t maps__fprintf(struct maps *maps, FILE *fp)
713 {
714 	size_t printed = 0;
715 	struct map *pos;
716 
717 	down_read(&maps->lock);
718 
719 	maps__for_each_entry(maps, pos) {
720 		printed += fprintf(fp, "Map:");
721 		printed += map__fprintf(pos, fp);
722 		if (verbose > 2) {
723 			printed += dso__fprintf(pos->dso, fp);
724 			printed += fprintf(fp, "--\n");
725 		}
726 	}
727 
728 	up_read(&maps->lock);
729 
730 	return printed;
731 }
732 
733 int maps__fixup_overlappings(struct maps *maps, struct map *map, FILE *fp)
734 {
735 	struct rb_root *root;
736 	struct rb_node *next, *first;
737 	int err = 0;
738 
739 	down_write(&maps->lock);
740 
741 	root = &maps->entries;
742 
743 	/*
744 	 * Find first map where end > map->start.
745 	 * Same as find_vma() in kernel.
746 	 */
747 	next = root->rb_node;
748 	first = NULL;
749 	while (next) {
750 		struct map *pos = rb_entry(next, struct map, rb_node);
751 
752 		if (pos->end > map->start) {
753 			first = next;
754 			if (pos->start <= map->start)
755 				break;
756 			next = next->rb_left;
757 		} else
758 			next = next->rb_right;
759 	}
760 
761 	next = first;
762 	while (next) {
763 		struct map *pos = rb_entry(next, struct map, rb_node);
764 		next = rb_next(&pos->rb_node);
765 
766 		/*
767 		 * Stop if current map starts after map->end.
768 		 * Maps are ordered by start: next will not overlap for sure.
769 		 */
770 		if (pos->start >= map->end)
771 			break;
772 
773 		if (verbose >= 2) {
774 
775 			if (use_browser) {
776 				pr_debug("overlapping maps in %s (disable tui for more info)\n",
777 					   map->dso->name);
778 			} else {
779 				fputs("overlapping maps:\n", fp);
780 				map__fprintf(map, fp);
781 				map__fprintf(pos, fp);
782 			}
783 		}
784 
785 		rb_erase_init(&pos->rb_node, root);
786 		/*
787 		 * Now check if we need to create new maps for areas not
788 		 * overlapped by the new map:
789 		 */
790 		if (map->start > pos->start) {
791 			struct map *before = map__clone(pos);
792 
793 			if (before == NULL) {
794 				err = -ENOMEM;
795 				goto put_map;
796 			}
797 
798 			before->end = map->start;
799 			__maps__insert(maps, before);
800 			if (verbose >= 2 && !use_browser)
801 				map__fprintf(before, fp);
802 			map__put(before);
803 		}
804 
805 		if (map->end < pos->end) {
806 			struct map *after = map__clone(pos);
807 
808 			if (after == NULL) {
809 				err = -ENOMEM;
810 				goto put_map;
811 			}
812 
813 			after->start = map->end;
814 			after->pgoff += map->end - pos->start;
815 			assert(pos->map_ip(pos, map->end) == after->map_ip(after, map->end));
816 			__maps__insert(maps, after);
817 			if (verbose >= 2 && !use_browser)
818 				map__fprintf(after, fp);
819 			map__put(after);
820 		}
821 put_map:
822 		map__put(pos);
823 
824 		if (err)
825 			goto out;
826 	}
827 
828 	err = 0;
829 out:
830 	up_write(&maps->lock);
831 	return err;
832 }
833 
834 /*
835  * XXX This should not really _copy_ te maps, but refcount them.
836  */
837 int maps__clone(struct thread *thread, struct maps *parent)
838 {
839 	struct maps *maps = thread->maps;
840 	int err = -ENOMEM;
841 	struct map *map;
842 
843 	down_read(&parent->lock);
844 
845 	maps__for_each_entry(parent, map) {
846 		struct map *new = map__clone(map);
847 		if (new == NULL)
848 			goto out_unlock;
849 
850 		err = unwind__prepare_access(maps, new, NULL);
851 		if (err)
852 			goto out_unlock;
853 
854 		maps__insert(maps, new);
855 		map__put(new);
856 	}
857 
858 	err = 0;
859 out_unlock:
860 	up_read(&parent->lock);
861 	return err;
862 }
863 
864 static void __maps__insert(struct maps *maps, struct map *map)
865 {
866 	struct rb_node **p = &maps->entries.rb_node;
867 	struct rb_node *parent = NULL;
868 	const u64 ip = map->start;
869 	struct map *m;
870 
871 	while (*p != NULL) {
872 		parent = *p;
873 		m = rb_entry(parent, struct map, rb_node);
874 		if (ip < m->start)
875 			p = &(*p)->rb_left;
876 		else
877 			p = &(*p)->rb_right;
878 	}
879 
880 	rb_link_node(&map->rb_node, parent, p);
881 	rb_insert_color(&map->rb_node, &maps->entries);
882 	map__get(map);
883 }
884 
885 struct map *maps__find(struct maps *maps, u64 ip)
886 {
887 	struct rb_node *p;
888 	struct map *m;
889 
890 	down_read(&maps->lock);
891 
892 	p = maps->entries.rb_node;
893 	while (p != NULL) {
894 		m = rb_entry(p, struct map, rb_node);
895 		if (ip < m->start)
896 			p = p->rb_left;
897 		else if (ip >= m->end)
898 			p = p->rb_right;
899 		else
900 			goto out;
901 	}
902 
903 	m = NULL;
904 out:
905 	up_read(&maps->lock);
906 	return m;
907 }
908 
909 struct map *maps__first(struct maps *maps)
910 {
911 	struct rb_node *first = rb_first(&maps->entries);
912 
913 	if (first)
914 		return rb_entry(first, struct map, rb_node);
915 	return NULL;
916 }
917 
918 static struct map *__map__next(struct map *map)
919 {
920 	struct rb_node *next = rb_next(&map->rb_node);
921 
922 	if (next)
923 		return rb_entry(next, struct map, rb_node);
924 	return NULL;
925 }
926 
927 struct map *map__next(struct map *map)
928 {
929 	return map ? __map__next(map) : NULL;
930 }
931 
932 struct kmap *__map__kmap(struct map *map)
933 {
934 	if (!map->dso || !map->dso->kernel)
935 		return NULL;
936 	return (struct kmap *)(map + 1);
937 }
938 
939 struct kmap *map__kmap(struct map *map)
940 {
941 	struct kmap *kmap = __map__kmap(map);
942 
943 	if (!kmap)
944 		pr_err("Internal error: map__kmap with a non-kernel map\n");
945 	return kmap;
946 }
947 
948 struct maps *map__kmaps(struct map *map)
949 {
950 	struct kmap *kmap = map__kmap(map);
951 
952 	if (!kmap || !kmap->kmaps) {
953 		pr_err("Internal error: map__kmaps with a non-kernel map\n");
954 		return NULL;
955 	}
956 	return kmap->kmaps;
957 }
958