xref: /openbmc/linux/tools/perf/util/map.c (revision ce746d43)
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_ool(const struct map *map)
271 {
272 	return map->dso && map->dso->binary_type == DSO_BINARY_TYPE__OOL;
273 }
274 
275 bool map__has_symbols(const struct map *map)
276 {
277 	return dso__has_symbols(map->dso);
278 }
279 
280 static void map__exit(struct map *map)
281 {
282 	BUG_ON(refcount_read(&map->refcnt) != 0);
283 	dso__zput(map->dso);
284 }
285 
286 void map__delete(struct map *map)
287 {
288 	map__exit(map);
289 	free(map);
290 }
291 
292 void map__put(struct map *map)
293 {
294 	if (map && refcount_dec_and_test(&map->refcnt))
295 		map__delete(map);
296 }
297 
298 void map__fixup_start(struct map *map)
299 {
300 	struct rb_root_cached *symbols = &map->dso->symbols;
301 	struct rb_node *nd = rb_first_cached(symbols);
302 	if (nd != NULL) {
303 		struct symbol *sym = rb_entry(nd, struct symbol, rb_node);
304 		map->start = sym->start;
305 	}
306 }
307 
308 void map__fixup_end(struct map *map)
309 {
310 	struct rb_root_cached *symbols = &map->dso->symbols;
311 	struct rb_node *nd = rb_last(&symbols->rb_root);
312 	if (nd != NULL) {
313 		struct symbol *sym = rb_entry(nd, struct symbol, rb_node);
314 		map->end = sym->end;
315 	}
316 }
317 
318 #define DSO__DELETED "(deleted)"
319 
320 int map__load(struct map *map)
321 {
322 	const char *name = map->dso->long_name;
323 	int nr;
324 
325 	if (dso__loaded(map->dso))
326 		return 0;
327 
328 	nr = dso__load(map->dso, map);
329 	if (nr < 0) {
330 		if (map->dso->has_build_id) {
331 			char sbuild_id[SBUILD_ID_SIZE];
332 
333 			build_id__sprintf(map->dso->build_id,
334 					  sizeof(map->dso->build_id),
335 					  sbuild_id);
336 			pr_debug("%s with build id %s not found", name, sbuild_id);
337 		} else
338 			pr_debug("Failed to open %s", name);
339 
340 		pr_debug(", continuing without symbols\n");
341 		return -1;
342 	} else if (nr == 0) {
343 #ifdef HAVE_LIBELF_SUPPORT
344 		const size_t len = strlen(name);
345 		const size_t real_len = len - sizeof(DSO__DELETED);
346 
347 		if (len > sizeof(DSO__DELETED) &&
348 		    strcmp(name + real_len + 1, DSO__DELETED) == 0) {
349 			pr_debug("%.*s was updated (is prelink enabled?). "
350 				"Restart the long running apps that use it!\n",
351 				   (int)real_len, name);
352 		} else {
353 			pr_debug("no symbols found in %s, maybe install a debug package?\n", name);
354 		}
355 #endif
356 		return -1;
357 	}
358 
359 	return 0;
360 }
361 
362 struct symbol *map__find_symbol(struct map *map, u64 addr)
363 {
364 	if (map__load(map) < 0)
365 		return NULL;
366 
367 	return dso__find_symbol(map->dso, addr);
368 }
369 
370 struct symbol *map__find_symbol_by_name(struct map *map, const char *name)
371 {
372 	if (map__load(map) < 0)
373 		return NULL;
374 
375 	if (!dso__sorted_by_name(map->dso))
376 		dso__sort_by_name(map->dso);
377 
378 	return dso__find_symbol_by_name(map->dso, name);
379 }
380 
381 struct map *map__clone(struct map *from)
382 {
383 	size_t size = sizeof(struct map);
384 	struct map *map;
385 
386 	if (from->dso && from->dso->kernel)
387 		size += sizeof(struct kmap);
388 
389 	map = memdup(from, size);
390 	if (map != NULL) {
391 		refcount_set(&map->refcnt, 1);
392 		RB_CLEAR_NODE(&map->rb_node);
393 		dso__get(map->dso);
394 	}
395 
396 	return map;
397 }
398 
399 size_t map__fprintf(struct map *map, FILE *fp)
400 {
401 	return fprintf(fp, " %" PRIx64 "-%" PRIx64 " %" PRIx64 " %s\n",
402 		       map->start, map->end, map->pgoff, map->dso->name);
403 }
404 
405 size_t map__fprintf_dsoname(struct map *map, FILE *fp)
406 {
407 	char buf[symbol_conf.pad_output_len_dso + 1];
408 	const char *dsoname = "[unknown]";
409 
410 	if (map && map->dso) {
411 		if (symbol_conf.show_kernel_path && map->dso->long_name)
412 			dsoname = map->dso->long_name;
413 		else
414 			dsoname = map->dso->name;
415 	}
416 
417 	if (symbol_conf.pad_output_len_dso) {
418 		scnprintf_pad(buf, symbol_conf.pad_output_len_dso, "%s", dsoname);
419 		dsoname = buf;
420 	}
421 
422 	return fprintf(fp, "%s", dsoname);
423 }
424 
425 char *map__srcline(struct map *map, u64 addr, struct symbol *sym)
426 {
427 	if (map == NULL)
428 		return SRCLINE_UNKNOWN;
429 	return get_srcline(map->dso, map__rip_2objdump(map, addr), sym, true, true, addr);
430 }
431 
432 int map__fprintf_srcline(struct map *map, u64 addr, const char *prefix,
433 			 FILE *fp)
434 {
435 	int ret = 0;
436 
437 	if (map && map->dso) {
438 		char *srcline = map__srcline(map, addr, NULL);
439 		if (strncmp(srcline, SRCLINE_UNKNOWN, strlen(SRCLINE_UNKNOWN)) != 0)
440 			ret = fprintf(fp, "%s%s", prefix, srcline);
441 		free_srcline(srcline);
442 	}
443 	return ret;
444 }
445 
446 void srccode_state_free(struct srccode_state *state)
447 {
448 	zfree(&state->srcfile);
449 	state->line = 0;
450 }
451 
452 /**
453  * map__rip_2objdump - convert symbol start address to objdump address.
454  * @map: memory map
455  * @rip: symbol start address
456  *
457  * objdump wants/reports absolute IPs for ET_EXEC, and RIPs for ET_DYN.
458  * map->dso->adjust_symbols==1 for ET_EXEC-like cases except ET_REL which is
459  * relative to section start.
460  *
461  * Return: Address suitable for passing to "objdump --start-address="
462  */
463 u64 map__rip_2objdump(struct map *map, u64 rip)
464 {
465 	struct kmap *kmap = __map__kmap(map);
466 
467 	/*
468 	 * vmlinux does not have program headers for PTI entry trampolines and
469 	 * kcore may not either. However the trampoline object code is on the
470 	 * main kernel map, so just use that instead.
471 	 */
472 	if (kmap && is_entry_trampoline(kmap->name) && kmap->kmaps && kmap->kmaps->machine) {
473 		struct map *kernel_map = machine__kernel_map(kmap->kmaps->machine);
474 
475 		if (kernel_map)
476 			map = kernel_map;
477 	}
478 
479 	if (!map->dso->adjust_symbols)
480 		return rip;
481 
482 	if (map->dso->rel)
483 		return rip - map->pgoff;
484 
485 	/*
486 	 * kernel modules also have DSO_TYPE_USER in dso->kernel,
487 	 * but all kernel modules are ET_REL, so won't get here.
488 	 */
489 	if (map->dso->kernel == DSO_TYPE_USER)
490 		return rip + map->dso->text_offset;
491 
492 	return map->unmap_ip(map, rip) - map->reloc;
493 }
494 
495 /**
496  * map__objdump_2mem - convert objdump address to a memory address.
497  * @map: memory map
498  * @ip: objdump address
499  *
500  * Closely related to map__rip_2objdump(), this function takes an address from
501  * objdump and converts it to a memory address.  Note this assumes that @map
502  * contains the address.  To be sure the result is valid, check it forwards
503  * e.g. map__rip_2objdump(map->map_ip(map, map__objdump_2mem(map, ip))) == ip
504  *
505  * Return: Memory address.
506  */
507 u64 map__objdump_2mem(struct map *map, u64 ip)
508 {
509 	if (!map->dso->adjust_symbols)
510 		return map->unmap_ip(map, ip);
511 
512 	if (map->dso->rel)
513 		return map->unmap_ip(map, ip + map->pgoff);
514 
515 	/*
516 	 * kernel modules also have DSO_TYPE_USER in dso->kernel,
517 	 * but all kernel modules are ET_REL, so won't get here.
518 	 */
519 	if (map->dso->kernel == DSO_TYPE_USER)
520 		return map->unmap_ip(map, ip - map->dso->text_offset);
521 
522 	return ip + map->reloc;
523 }
524 
525 void maps__init(struct maps *maps, struct machine *machine)
526 {
527 	maps->entries = RB_ROOT;
528 	init_rwsem(&maps->lock);
529 	maps->machine = machine;
530 	maps->last_search_by_name = NULL;
531 	maps->nr_maps = 0;
532 	maps->maps_by_name = NULL;
533 	refcount_set(&maps->refcnt, 1);
534 }
535 
536 static void __maps__free_maps_by_name(struct maps *maps)
537 {
538 	/*
539 	 * Free everything to try to do it from the rbtree in the next search
540 	 */
541 	zfree(&maps->maps_by_name);
542 	maps->nr_maps_allocated = 0;
543 }
544 
545 void maps__insert(struct maps *maps, struct map *map)
546 {
547 	down_write(&maps->lock);
548 	__maps__insert(maps, map);
549 	++maps->nr_maps;
550 
551 	if (map->dso && map->dso->kernel) {
552 		struct kmap *kmap = map__kmap(map);
553 
554 		if (kmap)
555 			kmap->kmaps = maps;
556 		else
557 			pr_err("Internal error: kernel dso with non kernel map\n");
558 	}
559 
560 
561 	/*
562 	 * If we already performed some search by name, then we need to add the just
563 	 * inserted map and resort.
564 	 */
565 	if (maps->maps_by_name) {
566 		if (maps->nr_maps > maps->nr_maps_allocated) {
567 			int nr_allocate = maps->nr_maps * 2;
568 			struct map **maps_by_name = realloc(maps->maps_by_name, nr_allocate * sizeof(map));
569 
570 			if (maps_by_name == NULL) {
571 				__maps__free_maps_by_name(maps);
572 				up_write(&maps->lock);
573 				return;
574 			}
575 
576 			maps->maps_by_name = maps_by_name;
577 			maps->nr_maps_allocated = nr_allocate;
578 		}
579 		maps->maps_by_name[maps->nr_maps - 1] = map;
580 		__maps__sort_by_name(maps);
581 	}
582 	up_write(&maps->lock);
583 }
584 
585 static void __maps__remove(struct maps *maps, struct map *map)
586 {
587 	rb_erase_init(&map->rb_node, &maps->entries);
588 	map__put(map);
589 }
590 
591 void maps__remove(struct maps *maps, struct map *map)
592 {
593 	down_write(&maps->lock);
594 	if (maps->last_search_by_name == map)
595 		maps->last_search_by_name = NULL;
596 
597 	__maps__remove(maps, map);
598 	--maps->nr_maps;
599 	if (maps->maps_by_name)
600 		__maps__free_maps_by_name(maps);
601 	up_write(&maps->lock);
602 }
603 
604 static void __maps__purge(struct maps *maps)
605 {
606 	struct map *pos, *next;
607 
608 	maps__for_each_entry_safe(maps, pos, next) {
609 		rb_erase_init(&pos->rb_node,  &maps->entries);
610 		map__put(pos);
611 	}
612 }
613 
614 void maps__exit(struct maps *maps)
615 {
616 	down_write(&maps->lock);
617 	__maps__purge(maps);
618 	up_write(&maps->lock);
619 }
620 
621 bool maps__empty(struct maps *maps)
622 {
623 	return !maps__first(maps);
624 }
625 
626 struct maps *maps__new(struct machine *machine)
627 {
628 	struct maps *maps = zalloc(sizeof(*maps));
629 
630 	if (maps != NULL)
631 		maps__init(maps, machine);
632 
633 	return maps;
634 }
635 
636 void maps__delete(struct maps *maps)
637 {
638 	maps__exit(maps);
639 	unwind__finish_access(maps);
640 	free(maps);
641 }
642 
643 void maps__put(struct maps *maps)
644 {
645 	if (maps && refcount_dec_and_test(&maps->refcnt))
646 		maps__delete(maps);
647 }
648 
649 struct symbol *maps__find_symbol(struct maps *maps, u64 addr, struct map **mapp)
650 {
651 	struct map *map = maps__find(maps, addr);
652 
653 	/* Ensure map is loaded before using map->map_ip */
654 	if (map != NULL && map__load(map) >= 0) {
655 		if (mapp != NULL)
656 			*mapp = map;
657 		return map__find_symbol(map, map->map_ip(map, addr));
658 	}
659 
660 	return NULL;
661 }
662 
663 static bool map__contains_symbol(struct map *map, struct symbol *sym)
664 {
665 	u64 ip = map->unmap_ip(map, sym->start);
666 
667 	return ip >= map->start && ip < map->end;
668 }
669 
670 struct symbol *maps__find_symbol_by_name(struct maps *maps, const char *name, struct map **mapp)
671 {
672 	struct symbol *sym;
673 	struct map *pos;
674 
675 	down_read(&maps->lock);
676 
677 	maps__for_each_entry(maps, pos) {
678 		sym = map__find_symbol_by_name(pos, name);
679 
680 		if (sym == NULL)
681 			continue;
682 		if (!map__contains_symbol(pos, sym)) {
683 			sym = NULL;
684 			continue;
685 		}
686 		if (mapp != NULL)
687 			*mapp = pos;
688 		goto out;
689 	}
690 
691 	sym = NULL;
692 out:
693 	up_read(&maps->lock);
694 	return sym;
695 }
696 
697 int maps__find_ams(struct maps *maps, struct addr_map_symbol *ams)
698 {
699 	if (ams->addr < ams->ms.map->start || ams->addr >= ams->ms.map->end) {
700 		if (maps == NULL)
701 			return -1;
702 		ams->ms.map = maps__find(maps, ams->addr);
703 		if (ams->ms.map == NULL)
704 			return -1;
705 	}
706 
707 	ams->al_addr = ams->ms.map->map_ip(ams->ms.map, ams->addr);
708 	ams->ms.sym = map__find_symbol(ams->ms.map, ams->al_addr);
709 
710 	return ams->ms.sym ? 0 : -1;
711 }
712 
713 size_t maps__fprintf(struct maps *maps, FILE *fp)
714 {
715 	size_t printed = 0;
716 	struct map *pos;
717 
718 	down_read(&maps->lock);
719 
720 	maps__for_each_entry(maps, pos) {
721 		printed += fprintf(fp, "Map:");
722 		printed += map__fprintf(pos, fp);
723 		if (verbose > 2) {
724 			printed += dso__fprintf(pos->dso, fp);
725 			printed += fprintf(fp, "--\n");
726 		}
727 	}
728 
729 	up_read(&maps->lock);
730 
731 	return printed;
732 }
733 
734 int maps__fixup_overlappings(struct maps *maps, struct map *map, FILE *fp)
735 {
736 	struct rb_root *root;
737 	struct rb_node *next, *first;
738 	int err = 0;
739 
740 	down_write(&maps->lock);
741 
742 	root = &maps->entries;
743 
744 	/*
745 	 * Find first map where end > map->start.
746 	 * Same as find_vma() in kernel.
747 	 */
748 	next = root->rb_node;
749 	first = NULL;
750 	while (next) {
751 		struct map *pos = rb_entry(next, struct map, rb_node);
752 
753 		if (pos->end > map->start) {
754 			first = next;
755 			if (pos->start <= map->start)
756 				break;
757 			next = next->rb_left;
758 		} else
759 			next = next->rb_right;
760 	}
761 
762 	next = first;
763 	while (next) {
764 		struct map *pos = rb_entry(next, struct map, rb_node);
765 		next = rb_next(&pos->rb_node);
766 
767 		/*
768 		 * Stop if current map starts after map->end.
769 		 * Maps are ordered by start: next will not overlap for sure.
770 		 */
771 		if (pos->start >= map->end)
772 			break;
773 
774 		if (verbose >= 2) {
775 
776 			if (use_browser) {
777 				pr_debug("overlapping maps in %s (disable tui for more info)\n",
778 					   map->dso->name);
779 			} else {
780 				fputs("overlapping maps:\n", fp);
781 				map__fprintf(map, fp);
782 				map__fprintf(pos, fp);
783 			}
784 		}
785 
786 		rb_erase_init(&pos->rb_node, root);
787 		/*
788 		 * Now check if we need to create new maps for areas not
789 		 * overlapped by the new map:
790 		 */
791 		if (map->start > pos->start) {
792 			struct map *before = map__clone(pos);
793 
794 			if (before == NULL) {
795 				err = -ENOMEM;
796 				goto put_map;
797 			}
798 
799 			before->end = map->start;
800 			__maps__insert(maps, before);
801 			if (verbose >= 2 && !use_browser)
802 				map__fprintf(before, fp);
803 			map__put(before);
804 		}
805 
806 		if (map->end < pos->end) {
807 			struct map *after = map__clone(pos);
808 
809 			if (after == NULL) {
810 				err = -ENOMEM;
811 				goto put_map;
812 			}
813 
814 			after->start = map->end;
815 			after->pgoff += map->end - pos->start;
816 			assert(pos->map_ip(pos, map->end) == after->map_ip(after, map->end));
817 			__maps__insert(maps, after);
818 			if (verbose >= 2 && !use_browser)
819 				map__fprintf(after, fp);
820 			map__put(after);
821 		}
822 put_map:
823 		map__put(pos);
824 
825 		if (err)
826 			goto out;
827 	}
828 
829 	err = 0;
830 out:
831 	up_write(&maps->lock);
832 	return err;
833 }
834 
835 /*
836  * XXX This should not really _copy_ te maps, but refcount them.
837  */
838 int maps__clone(struct thread *thread, struct maps *parent)
839 {
840 	struct maps *maps = thread->maps;
841 	int err = -ENOMEM;
842 	struct map *map;
843 
844 	down_read(&parent->lock);
845 
846 	maps__for_each_entry(parent, map) {
847 		struct map *new = map__clone(map);
848 		if (new == NULL)
849 			goto out_unlock;
850 
851 		err = unwind__prepare_access(maps, new, NULL);
852 		if (err)
853 			goto out_unlock;
854 
855 		maps__insert(maps, new);
856 		map__put(new);
857 	}
858 
859 	err = 0;
860 out_unlock:
861 	up_read(&parent->lock);
862 	return err;
863 }
864 
865 static void __maps__insert(struct maps *maps, struct map *map)
866 {
867 	struct rb_node **p = &maps->entries.rb_node;
868 	struct rb_node *parent = NULL;
869 	const u64 ip = map->start;
870 	struct map *m;
871 
872 	while (*p != NULL) {
873 		parent = *p;
874 		m = rb_entry(parent, struct map, rb_node);
875 		if (ip < m->start)
876 			p = &(*p)->rb_left;
877 		else
878 			p = &(*p)->rb_right;
879 	}
880 
881 	rb_link_node(&map->rb_node, parent, p);
882 	rb_insert_color(&map->rb_node, &maps->entries);
883 	map__get(map);
884 }
885 
886 struct map *maps__find(struct maps *maps, u64 ip)
887 {
888 	struct rb_node *p;
889 	struct map *m;
890 
891 	down_read(&maps->lock);
892 
893 	p = maps->entries.rb_node;
894 	while (p != NULL) {
895 		m = rb_entry(p, struct map, rb_node);
896 		if (ip < m->start)
897 			p = p->rb_left;
898 		else if (ip >= m->end)
899 			p = p->rb_right;
900 		else
901 			goto out;
902 	}
903 
904 	m = NULL;
905 out:
906 	up_read(&maps->lock);
907 	return m;
908 }
909 
910 struct map *maps__first(struct maps *maps)
911 {
912 	struct rb_node *first = rb_first(&maps->entries);
913 
914 	if (first)
915 		return rb_entry(first, struct map, rb_node);
916 	return NULL;
917 }
918 
919 static struct map *__map__next(struct map *map)
920 {
921 	struct rb_node *next = rb_next(&map->rb_node);
922 
923 	if (next)
924 		return rb_entry(next, struct map, rb_node);
925 	return NULL;
926 }
927 
928 struct map *map__next(struct map *map)
929 {
930 	return map ? __map__next(map) : NULL;
931 }
932 
933 struct kmap *__map__kmap(struct map *map)
934 {
935 	if (!map->dso || !map->dso->kernel)
936 		return NULL;
937 	return (struct kmap *)(map + 1);
938 }
939 
940 struct kmap *map__kmap(struct map *map)
941 {
942 	struct kmap *kmap = __map__kmap(map);
943 
944 	if (!kmap)
945 		pr_err("Internal error: map__kmap with a non-kernel map\n");
946 	return kmap;
947 }
948 
949 struct maps *map__kmaps(struct map *map)
950 {
951 	struct kmap *kmap = map__kmap(map);
952 
953 	if (!kmap || !kmap->kmaps) {
954 		pr_err("Internal error: map__kmaps with a non-kernel map\n");
955 		return NULL;
956 	}
957 	return kmap->kmaps;
958 }
959