1 // SPDX-License-Identifier: GPL-2.0
2 #include <errno.h>
3 #include <stdlib.h>
4 #include <linux/zalloc.h>
5 #include "debug.h"
6 #include "dso.h"
7 #include "map.h"
8 #include "maps.h"
9 #include "rwsem.h"
10 #include "thread.h"
11 #include "ui/ui.h"
12 #include "unwind.h"
13 #include <internal/rc_check.h>
14
15 /*
16 * Locking/sorting note:
17 *
18 * Sorting is done with the write lock, iteration and binary searching happens
19 * under the read lock requiring being sorted. There is a race between sorting
20 * releasing the write lock and acquiring the read lock for iteration/searching
21 * where another thread could insert and break the sorting of the maps. In
22 * practice inserting maps should be rare meaning that the race shouldn't lead
23 * to live lock. Removal of maps doesn't break being sorted.
24 */
25
26 DECLARE_RC_STRUCT(maps) {
27 struct rw_semaphore lock;
28 /**
29 * @maps_by_address: array of maps sorted by their starting address if
30 * maps_by_address_sorted is true.
31 */
32 struct map **maps_by_address;
33 /**
34 * @maps_by_name: optional array of maps sorted by their dso name if
35 * maps_by_name_sorted is true.
36 */
37 struct map **maps_by_name;
38 struct machine *machine;
39 #ifdef HAVE_LIBUNWIND_SUPPORT
40 void *addr_space;
41 const struct unwind_libunwind_ops *unwind_libunwind_ops;
42 #endif
43 refcount_t refcnt;
44 /**
45 * @nr_maps: number of maps_by_address, and possibly maps_by_name,
46 * entries that contain maps.
47 */
48 unsigned int nr_maps;
49 /**
50 * @nr_maps_allocated: number of entries in maps_by_address and possibly
51 * maps_by_name.
52 */
53 unsigned int nr_maps_allocated;
54 /**
55 * @last_search_by_name_idx: cache of last found by name entry's index
56 * as frequent searches for the same dso name are common.
57 */
58 unsigned int last_search_by_name_idx;
59 /** @maps_by_address_sorted: is maps_by_address sorted. */
60 bool maps_by_address_sorted;
61 /** @maps_by_name_sorted: is maps_by_name sorted. */
62 bool maps_by_name_sorted;
63 /** @ends_broken: does the map contain a map where end values are unset/unsorted? */
64 bool ends_broken;
65 };
66
67 static void check_invariants(const struct maps *maps __maybe_unused)
68 {
69 #ifndef NDEBUG
70 assert(RC_CHK_ACCESS(maps)->nr_maps <= RC_CHK_ACCESS(maps)->nr_maps_allocated);
71 for (unsigned int i = 0; i < RC_CHK_ACCESS(maps)->nr_maps; i++) {
72 struct map *map = RC_CHK_ACCESS(maps)->maps_by_address[i];
73
74 /* Check map is well-formed. */
75 assert(map__end(map) == 0 || map__start(map) <= map__end(map));
76 /* Expect at least 1 reference count. */
77 assert(refcount_read(map__refcnt(map)) > 0);
78
79 if (map__dso(map) && dso__kernel(map__dso(map)))
80 assert(RC_CHK_EQUAL(map__kmap(map)->kmaps, maps));
81
82 if (i > 0) {
83 struct map *prev = RC_CHK_ACCESS(maps)->maps_by_address[i - 1];
84
85 /* If addresses are sorted... */
86 if (RC_CHK_ACCESS(maps)->maps_by_address_sorted) {
87 /* Maps should be in start address order. */
88 assert(map__start(prev) <= map__start(map));
89 /*
90 * If the ends of maps aren't broken (during
91 * construction) then they should be ordered
92 * too.
93 */
94 if (!RC_CHK_ACCESS(maps)->ends_broken) {
95 assert(map__end(prev) <= map__end(map));
96 assert(map__end(prev) <= map__start(map) ||
97 map__start(prev) == map__start(map));
98 }
99 }
100 }
101 }
102 if (RC_CHK_ACCESS(maps)->maps_by_name) {
103 for (unsigned int i = 0; i < RC_CHK_ACCESS(maps)->nr_maps; i++) {
104 struct map *map = RC_CHK_ACCESS(maps)->maps_by_name[i];
105
106 /*
107 * Maps by name maps should be in maps_by_address, so
108 * the reference count should be higher.
109 */
110 assert(refcount_read(map__refcnt(map)) > 1);
111 }
112 }
113 #endif
114 }
115
116 static struct map **maps__maps_by_address(const struct maps *maps)
117 {
118 return RC_CHK_ACCESS(maps)->maps_by_address;
119 }
120
121 static void maps__set_maps_by_address(struct maps *maps, struct map **new)
122 {
123 RC_CHK_ACCESS(maps)->maps_by_address = new;
124
125 }
126
127 static void maps__set_nr_maps_allocated(struct maps *maps, unsigned int nr_maps_allocated)
128 {
129 RC_CHK_ACCESS(maps)->nr_maps_allocated = nr_maps_allocated;
130 }
131
132 static void maps__set_nr_maps(struct maps *maps, unsigned int nr_maps)
133 {
134 RC_CHK_ACCESS(maps)->nr_maps = nr_maps;
135 }
136
137 /* Not in the header, to aid reference counting. */
138 static struct map **maps__maps_by_name(const struct maps *maps)
139 {
140 return RC_CHK_ACCESS(maps)->maps_by_name;
141
142 }
143
144 static void maps__set_maps_by_name(struct maps *maps, struct map **new)
145 {
146 RC_CHK_ACCESS(maps)->maps_by_name = new;
147
148 }
149
150 static bool maps__maps_by_address_sorted(const struct maps *maps)
151 {
152 return RC_CHK_ACCESS(maps)->maps_by_address_sorted;
153 }
154
155 static void maps__set_maps_by_address_sorted(struct maps *maps, bool value)
156 {
157 RC_CHK_ACCESS(maps)->maps_by_address_sorted = value;
158 }
159
160 static bool maps__maps_by_name_sorted(const struct maps *maps)
161 {
162 return RC_CHK_ACCESS(maps)->maps_by_name_sorted;
163 }
164
165 static void maps__set_maps_by_name_sorted(struct maps *maps, bool value)
166 {
167 RC_CHK_ACCESS(maps)->maps_by_name_sorted = value;
168 }
169
170 struct machine *maps__machine(const struct maps *maps)
171 {
172 return RC_CHK_ACCESS(maps)->machine;
173 }
174
175 unsigned int maps__nr_maps(const struct maps *maps)
176 {
177 return RC_CHK_ACCESS(maps)->nr_maps;
178 }
179
180 refcount_t *maps__refcnt(struct maps *maps)
181 {
182 return &RC_CHK_ACCESS(maps)->refcnt;
183 }
184
185 #ifdef HAVE_LIBUNWIND_SUPPORT
186 void *maps__addr_space(const struct maps *maps)
187 {
188 return RC_CHK_ACCESS(maps)->addr_space;
189 }
190
191 void maps__set_addr_space(struct maps *maps, void *addr_space)
192 {
193 RC_CHK_ACCESS(maps)->addr_space = addr_space;
194 }
195
196 const struct unwind_libunwind_ops *maps__unwind_libunwind_ops(const struct maps *maps)
197 {
198 return RC_CHK_ACCESS(maps)->unwind_libunwind_ops;
199 }
200
201 void maps__set_unwind_libunwind_ops(struct maps *maps, const struct unwind_libunwind_ops *ops)
202 {
203 RC_CHK_ACCESS(maps)->unwind_libunwind_ops = ops;
204 }
205 #endif
206
207 static struct rw_semaphore *maps__lock(struct maps *maps)
208 {
209 return &RC_CHK_ACCESS(maps)->lock;
210 }
211
212 static void maps__init(struct maps *maps, struct machine *machine)
213 {
214 init_rwsem(maps__lock(maps));
215 RC_CHK_ACCESS(maps)->maps_by_address = NULL;
216 RC_CHK_ACCESS(maps)->maps_by_name = NULL;
217 RC_CHK_ACCESS(maps)->machine = machine;
218 #ifdef HAVE_LIBUNWIND_SUPPORT
219 RC_CHK_ACCESS(maps)->addr_space = NULL;
220 RC_CHK_ACCESS(maps)->unwind_libunwind_ops = NULL;
221 #endif
222 refcount_set(maps__refcnt(maps), 1);
223 RC_CHK_ACCESS(maps)->nr_maps = 0;
224 RC_CHK_ACCESS(maps)->nr_maps_allocated = 0;
225 RC_CHK_ACCESS(maps)->last_search_by_name_idx = 0;
226 RC_CHK_ACCESS(maps)->maps_by_address_sorted = true;
227 RC_CHK_ACCESS(maps)->maps_by_name_sorted = false;
228 }
229
230 static void maps__exit(struct maps *maps)
231 {
232 struct map **maps_by_address = maps__maps_by_address(maps);
233 struct map **maps_by_name = maps__maps_by_name(maps);
234
235 for (unsigned int i = 0; i < maps__nr_maps(maps); i++) {
236 map__zput(maps_by_address[i]);
237 if (maps_by_name)
238 map__zput(maps_by_name[i]);
239 }
240 zfree(&maps_by_address);
241 zfree(&maps_by_name);
242 unwind__finish_access(maps);
243 }
244
245 struct maps *maps__new(struct machine *machine)
246 {
247 struct maps *result;
248 RC_STRUCT(maps) *maps = zalloc(sizeof(*maps));
249
250 if (ADD_RC_CHK(result, maps))
251 maps__init(result, machine);
252
253 return result;
254 }
255
256 static void maps__delete(struct maps *maps)
257 {
258 maps__exit(maps);
259 RC_CHK_FREE(maps);
260 }
261
262 struct maps *maps__get(struct maps *maps)
263 {
264 struct maps *result;
265
266 if (RC_CHK_GET(result, maps))
267 refcount_inc(maps__refcnt(maps));
268
269 return result;
270 }
271
272 void maps__put(struct maps *maps)
273 {
274 if (maps && refcount_dec_and_test(maps__refcnt(maps)))
275 maps__delete(maps);
276 else
277 RC_CHK_PUT(maps);
278 }
279
280 static void __maps__free_maps_by_name(struct maps *maps)
281 {
282 if (!maps__maps_by_name(maps))
283 return;
284
285 /*
286 * Free everything to try to do it from the rbtree in the next search
287 */
288 for (unsigned int i = 0; i < maps__nr_maps(maps); i++)
289 map__put(maps__maps_by_name(maps)[i]);
290
291 zfree(&RC_CHK_ACCESS(maps)->maps_by_name);
292
293 /* Consistent with maps__init(). When maps_by_name == NULL, maps_by_name_sorted == false */
294 maps__set_maps_by_name_sorted(maps, false);
295 }
296
297 static int map__start_cmp(const void *a, const void *b)
298 {
299 const struct map *map_a = *(const struct map * const *)a;
300 const struct map *map_b = *(const struct map * const *)b;
301 u64 map_a_start = map__start(map_a);
302 u64 map_b_start = map__start(map_b);
303
304 if (map_a_start == map_b_start) {
305 u64 map_a_end = map__end(map_a);
306 u64 map_b_end = map__end(map_b);
307
308 if (map_a_end == map_b_end) {
309 /* Ensure maps with the same addresses have a fixed order. */
310 if (RC_CHK_ACCESS(map_a) == RC_CHK_ACCESS(map_b))
311 return 0;
312 return (intptr_t)RC_CHK_ACCESS(map_a) > (intptr_t)RC_CHK_ACCESS(map_b)
313 ? 1 : -1;
314 }
315 return map_a_end > map_b_end ? 1 : -1;
316 }
317 return map_a_start > map_b_start ? 1 : -1;
318 }
319
320 static void __maps__sort_by_address(struct maps *maps)
321 {
322 if (maps__maps_by_address_sorted(maps))
323 return;
324
325 qsort(maps__maps_by_address(maps),
326 maps__nr_maps(maps),
327 sizeof(struct map *),
328 map__start_cmp);
329 maps__set_maps_by_address_sorted(maps, true);
330 }
331
332 static void maps__sort_by_address(struct maps *maps)
333 {
334 down_write(maps__lock(maps));
335 __maps__sort_by_address(maps);
336 up_write(maps__lock(maps));
337 }
338
339 static int map__strcmp(const void *a, const void *b)
340 {
341 const struct map *map_a = *(const struct map * const *)a;
342 const struct map *map_b = *(const struct map * const *)b;
343 const struct dso *dso_a = map__dso(map_a);
344 const struct dso *dso_b = map__dso(map_b);
345 int ret = strcmp(dso__short_name(dso_a), dso__short_name(dso_b));
346
347 if (ret == 0 && RC_CHK_ACCESS(map_a) != RC_CHK_ACCESS(map_b)) {
348 /* Ensure distinct but name equal maps have an order. */
349 return map__start_cmp(a, b);
350 }
351 return ret;
352 }
353
354 static int maps__sort_by_name(struct maps *maps)
355 {
356 int err = 0;
357
358 down_write(maps__lock(maps));
359 if (!maps__maps_by_name_sorted(maps)) {
360 struct map **maps_by_name = maps__maps_by_name(maps);
361
362 if (!maps_by_name) {
363 maps_by_name = malloc(RC_CHK_ACCESS(maps)->nr_maps_allocated *
364 sizeof(*maps_by_name));
365 if (!maps_by_name)
366 err = -ENOMEM;
367 else {
368 struct map **maps_by_address = maps__maps_by_address(maps);
369 unsigned int n = maps__nr_maps(maps);
370
371 maps__set_maps_by_name(maps, maps_by_name);
372 for (unsigned int i = 0; i < n; i++)
373 maps_by_name[i] = map__get(maps_by_address[i]);
374 }
375 }
376 if (!err) {
377 qsort(maps_by_name,
378 maps__nr_maps(maps),
379 sizeof(struct map *),
380 map__strcmp);
381 maps__set_maps_by_name_sorted(maps, true);
382 }
383 }
384 check_invariants(maps);
385 up_write(maps__lock(maps));
386 return err;
387 }
388
389 static unsigned int maps__by_address_index(const struct maps *maps, const struct map *map)
390 {
391 struct map **maps_by_address = maps__maps_by_address(maps);
392
393 if (maps__maps_by_address_sorted(maps)) {
394 struct map **mapp =
395 bsearch(&map, maps__maps_by_address(maps), maps__nr_maps(maps),
396 sizeof(*mapp), map__start_cmp);
397
398 if (mapp)
399 return mapp - maps_by_address;
400 } else {
401 for (unsigned int i = 0; i < maps__nr_maps(maps); i++) {
402 if (RC_CHK_ACCESS(maps_by_address[i]) == RC_CHK_ACCESS(map))
403 return i;
404 }
405 }
406 pr_err("Map missing from maps");
407 return -1;
408 }
409
410 static unsigned int maps__by_name_index(const struct maps *maps, const struct map *map)
411 {
412 struct map **maps_by_name = maps__maps_by_name(maps);
413
414 if (maps__maps_by_name_sorted(maps)) {
415 struct map **mapp =
416 bsearch(&map, maps_by_name, maps__nr_maps(maps),
417 sizeof(*mapp), map__strcmp);
418
419 if (mapp)
420 return mapp - maps_by_name;
421 } else {
422 for (unsigned int i = 0; i < maps__nr_maps(maps); i++) {
423 if (RC_CHK_ACCESS(maps_by_name[i]) == RC_CHK_ACCESS(map))
424 return i;
425 }
426 }
427 pr_err("Map missing from maps");
428 return -1;
429 }
430
431 static int __maps__insert(struct maps *maps, struct map *new)
432 {
433 struct map **maps_by_address = maps__maps_by_address(maps);
434 struct map **maps_by_name = maps__maps_by_name(maps);
435 const struct dso *dso = map__dso(new);
436 unsigned int nr_maps = maps__nr_maps(maps);
437 unsigned int nr_allocate = RC_CHK_ACCESS(maps)->nr_maps_allocated;
438
439 if (nr_maps + 1 > nr_allocate) {
440 nr_allocate = !nr_allocate ? 32 : nr_allocate * 2;
441
442 maps_by_address = realloc(maps_by_address, nr_allocate * sizeof(new));
443 if (!maps_by_address)
444 return -ENOMEM;
445
446 maps__set_maps_by_address(maps, maps_by_address);
447 if (maps_by_name) {
448 maps_by_name = realloc(maps_by_name, nr_allocate * sizeof(new));
449 if (!maps_by_name) {
450 /*
451 * If by name fails, just disable by name and it will
452 * recompute next time it is required.
453 */
454 __maps__free_maps_by_name(maps);
455 }
456 maps__set_maps_by_name(maps, maps_by_name);
457 }
458 RC_CHK_ACCESS(maps)->nr_maps_allocated = nr_allocate;
459 }
460 /* Insert the value at the end. */
461 maps_by_address[nr_maps] = map__get(new);
462 if (maps_by_name)
463 maps_by_name[nr_maps] = map__get(new);
464
465 nr_maps++;
466 RC_CHK_ACCESS(maps)->nr_maps = nr_maps;
467
468 /*
469 * Recompute if things are sorted. If things are inserted in a sorted
470 * manner, for example by processing /proc/pid/maps, then no
471 * sorting/resorting will be necessary.
472 */
473 if (nr_maps == 1) {
474 /* If there's just 1 entry then maps are sorted. */
475 maps__set_maps_by_address_sorted(maps, true);
476 maps__set_maps_by_name_sorted(maps, maps_by_name != NULL);
477 } else {
478 /* Sorted if maps were already sorted and this map starts after the last one. */
479 maps__set_maps_by_address_sorted(maps,
480 maps__maps_by_address_sorted(maps) &&
481 map__end(maps_by_address[nr_maps - 2]) <= map__start(new));
482 maps__set_maps_by_name_sorted(maps, false);
483 }
484 if (map__end(new) < map__start(new))
485 RC_CHK_ACCESS(maps)->ends_broken = true;
486 if (dso && dso__kernel(dso)) {
487 struct kmap *kmap = map__kmap(new);
488
489 if (kmap)
490 kmap->kmaps = maps;
491 else
492 pr_err("Internal error: kernel dso with non kernel map\n");
493 }
494 return 0;
495 }
496
497 int maps__insert(struct maps *maps, struct map *map)
498 {
499 int ret;
500
501 down_write(maps__lock(maps));
502 ret = __maps__insert(maps, map);
503 check_invariants(maps);
504 up_write(maps__lock(maps));
505 return ret;
506 }
507
508 static void __maps__remove(struct maps *maps, struct map *map)
509 {
510 struct map **maps_by_address = maps__maps_by_address(maps);
511 struct map **maps_by_name = maps__maps_by_name(maps);
512 unsigned int nr_maps = maps__nr_maps(maps);
513 unsigned int address_idx;
514
515 /* Slide later mappings over the one to remove */
516 address_idx = maps__by_address_index(maps, map);
517 map__put(maps_by_address[address_idx]);
518 memmove(&maps_by_address[address_idx],
519 &maps_by_address[address_idx + 1],
520 (nr_maps - address_idx - 1) * sizeof(*maps_by_address));
521
522 if (maps_by_name) {
523 unsigned int name_idx = maps__by_name_index(maps, map);
524
525 map__put(maps_by_name[name_idx]);
526 memmove(&maps_by_name[name_idx],
527 &maps_by_name[name_idx + 1],
528 (nr_maps - name_idx - 1) * sizeof(*maps_by_name));
529 }
530
531 --RC_CHK_ACCESS(maps)->nr_maps;
532 }
533
534 void maps__remove(struct maps *maps, struct map *map)
535 {
536 down_write(maps__lock(maps));
537 __maps__remove(maps, map);
538 check_invariants(maps);
539 up_write(maps__lock(maps));
540 }
541
542 bool maps__empty(struct maps *maps)
543 {
544 bool res;
545
546 down_read(maps__lock(maps));
547 res = maps__nr_maps(maps) == 0;
548 up_read(maps__lock(maps));
549
550 return res;
551 }
552
553 bool maps__equal(struct maps *a, struct maps *b)
554 {
555 return RC_CHK_EQUAL(a, b);
556 }
557
558 int maps__for_each_map(struct maps *maps, int (*cb)(struct map *map, void *data), void *data)
559 {
560 bool done = false;
561 int ret = 0;
562
563 /* See locking/sorting note. */
564 while (!done) {
565 down_read(maps__lock(maps));
566 if (maps__maps_by_address_sorted(maps)) {
567 /*
568 * maps__for_each_map callbacks may buggily/unsafely
569 * insert into maps_by_address. Deliberately reload
570 * maps__nr_maps and maps_by_address on each iteration
571 * to avoid using memory freed by maps__insert growing
572 * the array - this may cause maps to be skipped or
573 * repeated.
574 */
575 for (unsigned int i = 0; i < maps__nr_maps(maps); i++) {
576 struct map **maps_by_address = maps__maps_by_address(maps);
577 struct map *map = maps_by_address[i];
578
579 ret = cb(map, data);
580 if (ret)
581 break;
582 }
583 done = true;
584 }
585 up_read(maps__lock(maps));
586 if (!done)
587 maps__sort_by_address(maps);
588 }
589 return ret;
590 }
591
592 void maps__remove_maps(struct maps *maps, bool (*cb)(struct map *map, void *data), void *data)
593 {
594 struct map **maps_by_address;
595
596 down_write(maps__lock(maps));
597
598 maps_by_address = maps__maps_by_address(maps);
599 for (unsigned int i = 0; i < maps__nr_maps(maps);) {
600 if (cb(maps_by_address[i], data))
601 __maps__remove(maps, maps_by_address[i]);
602 else
603 i++;
604 }
605 check_invariants(maps);
606 up_write(maps__lock(maps));
607 }
608
609 struct symbol *maps__find_symbol(struct maps *maps, u64 addr, struct map **mapp)
610 {
611 struct map *map = maps__find(maps, addr);
612 struct symbol *result = NULL;
613
614 /* Ensure map is loaded before using map->map_ip */
615 if (map != NULL && map__load(map) >= 0)
616 result = map__find_symbol(map, map__map_ip(map, addr));
617
618 if (mapp)
619 *mapp = map;
620 else
621 map__put(map);
622
623 return result;
624 }
625
626 struct maps__find_symbol_by_name_args {
627 struct map **mapp;
628 const char *name;
629 struct symbol *sym;
630 };
631
632 static int maps__find_symbol_by_name_cb(struct map *map, void *data)
633 {
634 struct maps__find_symbol_by_name_args *args = data;
635
636 args->sym = map__find_symbol_by_name(map, args->name);
637 if (!args->sym)
638 return 0;
639
640 if (!map__contains_symbol(map, args->sym)) {
641 args->sym = NULL;
642 return 0;
643 }
644
645 if (args->mapp != NULL)
646 *args->mapp = map__get(map);
647 return 1;
648 }
649
650 struct symbol *maps__find_symbol_by_name(struct maps *maps, const char *name, struct map **mapp)
651 {
652 struct maps__find_symbol_by_name_args args = {
653 .mapp = mapp,
654 .name = name,
655 .sym = NULL,
656 };
657
658 maps__for_each_map(maps, maps__find_symbol_by_name_cb, &args);
659 return args.sym;
660 }
661
662 int maps__find_ams(struct maps *maps, struct addr_map_symbol *ams)
663 {
664 if (ams->addr < map__start(ams->ms.map) || ams->addr >= map__end(ams->ms.map)) {
665 if (maps == NULL)
666 return -1;
667 ams->ms.map = maps__find(maps, ams->addr);
668 if (ams->ms.map == NULL)
669 return -1;
670 }
671
672 ams->al_addr = map__map_ip(ams->ms.map, ams->addr);
673 ams->ms.sym = map__find_symbol(ams->ms.map, ams->al_addr);
674
675 return ams->ms.sym ? 0 : -1;
676 }
677
678 struct maps__fprintf_args {
679 FILE *fp;
680 size_t printed;
681 };
682
683 static int maps__fprintf_cb(struct map *map, void *data)
684 {
685 struct maps__fprintf_args *args = data;
686
687 args->printed += fprintf(args->fp, "Map:");
688 args->printed += map__fprintf(map, args->fp);
689 if (verbose > 2) {
690 args->printed += dso__fprintf(map__dso(map), args->fp);
691 args->printed += fprintf(args->fp, "--\n");
692 }
693 return 0;
694 }
695
696 size_t maps__fprintf(struct maps *maps, FILE *fp)
697 {
698 struct maps__fprintf_args args = {
699 .fp = fp,
700 .printed = 0,
701 };
702
703 maps__for_each_map(maps, maps__fprintf_cb, &args);
704
705 return args.printed;
706 }
707
708 /*
709 * Find first map where end > map->start.
710 * Same as find_vma() in kernel.
711 */
712 static unsigned int first_ending_after(struct maps *maps, const struct map *map)
713 {
714 struct map **maps_by_address = maps__maps_by_address(maps);
715 int low = 0, high = (int)maps__nr_maps(maps) - 1, first = high + 1;
716
717 assert(maps__maps_by_address_sorted(maps));
718 if (low <= high && map__end(maps_by_address[0]) > map__start(map))
719 return 0;
720
721 while (low <= high) {
722 int mid = (low + high) / 2;
723 struct map *pos = maps_by_address[mid];
724
725 if (map__end(pos) > map__start(map)) {
726 first = mid;
727 if (map__start(pos) <= map__start(map)) {
728 /* Entry overlaps map. */
729 break;
730 }
731 high = mid - 1;
732 } else
733 low = mid + 1;
734 }
735 return first;
736 }
737
738 static int __maps__insert_sorted(struct maps *maps, unsigned int first_after_index,
739 struct map *new1, struct map *new2)
740 {
741 struct map **maps_by_address = maps__maps_by_address(maps);
742 struct map **maps_by_name = maps__maps_by_name(maps);
743 unsigned int nr_maps = maps__nr_maps(maps);
744 unsigned int nr_allocate = RC_CHK_ACCESS(maps)->nr_maps_allocated;
745 unsigned int to_add = new2 ? 2 : 1;
746
747 assert(maps__maps_by_address_sorted(maps));
748 assert(first_after_index == nr_maps ||
749 map__end(new1) <= map__start(maps_by_address[first_after_index]));
750 assert(!new2 || map__end(new1) <= map__start(new2));
751 assert(first_after_index == nr_maps || !new2 ||
752 map__end(new2) <= map__start(maps_by_address[first_after_index]));
753
754 if (nr_maps + to_add > nr_allocate) {
755 nr_allocate = !nr_allocate ? 32 : nr_allocate * 2;
756
757 maps_by_address = realloc(maps_by_address, nr_allocate * sizeof(new1));
758 if (!maps_by_address)
759 return -ENOMEM;
760
761 maps__set_maps_by_address(maps, maps_by_address);
762 if (maps_by_name) {
763 maps_by_name = realloc(maps_by_name, nr_allocate * sizeof(new1));
764 if (!maps_by_name) {
765 /*
766 * If by name fails, just disable by name and it will
767 * recompute next time it is required.
768 */
769 __maps__free_maps_by_name(maps);
770 }
771 maps__set_maps_by_name(maps, maps_by_name);
772 }
773 RC_CHK_ACCESS(maps)->nr_maps_allocated = nr_allocate;
774 }
775 memmove(&maps_by_address[first_after_index+to_add],
776 &maps_by_address[first_after_index],
777 (nr_maps - first_after_index) * sizeof(new1));
778 maps_by_address[first_after_index] = map__get(new1);
779 if (maps_by_name)
780 maps_by_name[nr_maps] = map__get(new1);
781 if (new2) {
782 maps_by_address[first_after_index + 1] = map__get(new2);
783 if (maps_by_name)
784 maps_by_name[nr_maps + 1] = map__get(new2);
785 }
786 RC_CHK_ACCESS(maps)->nr_maps = nr_maps + to_add;
787 maps__set_maps_by_name_sorted(maps, false);
788 check_invariants(maps);
789 return 0;
790 }
791
792 /*
793 * Adds new to maps, if new overlaps existing entries then the existing maps are
794 * adjusted or removed so that new fits without overlapping any entries.
795 */
796 static int __maps__fixup_overlap_and_insert(struct maps *maps, struct map *new)
797 {
798 int err = 0;
799 FILE *fp = debug_file();
800 unsigned int i;
801
802 if (!maps__maps_by_address_sorted(maps))
803 __maps__sort_by_address(maps);
804
805 /*
806 * Iterate through entries where the end of the existing entry is
807 * greater-than the new map's start.
808 */
809 for (i = first_ending_after(maps, new); i < maps__nr_maps(maps); ) {
810 struct map **maps_by_address = maps__maps_by_address(maps);
811 struct map *pos = maps_by_address[i];
812 struct map *before = NULL, *after = NULL;
813
814 /*
815 * Stop if current map starts after map->end.
816 * Maps are ordered by start: next will not overlap for sure.
817 */
818 if (map__start(pos) >= map__end(new))
819 break;
820
821 if (use_browser) {
822 pr_debug("overlapping maps in %s (disable tui for more info)\n",
823 dso__name(map__dso(new)));
824 } else if (verbose >= 2) {
825 pr_debug("overlapping maps:\n");
826 map__fprintf(new, fp);
827 map__fprintf(pos, fp);
828 }
829
830 /*
831 * Now check if we need to create new maps for areas not
832 * overlapped by the new map:
833 */
834 if (map__start(new) > map__start(pos)) {
835 /* Map starts within existing map. Need to shorten the existing map. */
836 before = map__clone(pos);
837
838 if (before == NULL) {
839 err = -ENOMEM;
840 goto out_err;
841 }
842 map__set_end(before, map__start(new));
843
844 if (verbose >= 2 && !use_browser)
845 map__fprintf(before, fp);
846 }
847 if (map__end(new) < map__end(pos)) {
848 /* The new map isn't as long as the existing map. */
849 after = map__clone(pos);
850
851 if (after == NULL) {
852 map__zput(before);
853 err = -ENOMEM;
854 goto out_err;
855 }
856
857 map__set_start(after, map__end(new));
858 map__add_pgoff(after, map__end(new) - map__start(pos));
859 assert(map__map_ip(pos, map__end(new)) ==
860 map__map_ip(after, map__end(new)));
861
862 if (verbose >= 2 && !use_browser)
863 map__fprintf(after, fp);
864 }
865 /*
866 * If adding one entry, for `before` or `after`, we can replace
867 * the existing entry. If both `before` and `after` are
868 * necessary than an insert is needed. If the existing entry
869 * entirely overlaps the existing entry it can just be removed.
870 */
871 if (before) {
872 map__put(maps_by_address[i]);
873 maps_by_address[i] = before;
874 /* Maps are still ordered, go to next one. */
875 i++;
876 if (after) {
877 /*
878 * 'before' and 'after' mean 'new' split the
879 * 'pos' mapping and therefore there are no
880 * later mappings.
881 */
882 err = __maps__insert_sorted(maps, i, new, after);
883 map__put(after);
884 check_invariants(maps);
885 return err;
886 }
887 check_invariants(maps);
888 } else if (after) {
889 /*
890 * 'after' means 'new' split 'pos' and there are no
891 * later mappings.
892 */
893 map__put(maps_by_address[i]);
894 maps_by_address[i] = map__get(new);
895 err = __maps__insert_sorted(maps, i + 1, after, NULL);
896 map__put(after);
897 check_invariants(maps);
898 return err;
899 } else {
900 struct map *next = NULL;
901
902 if (i + 1 < maps__nr_maps(maps))
903 next = maps_by_address[i + 1];
904
905 if (!next || map__start(next) >= map__end(new)) {
906 /*
907 * Replace existing mapping and end knowing
908 * there aren't later overlapping or any
909 * mappings.
910 */
911 map__put(maps_by_address[i]);
912 maps_by_address[i] = map__get(new);
913 check_invariants(maps);
914 return err;
915 }
916 __maps__remove(maps, pos);
917 check_invariants(maps);
918 /*
919 * Maps are ordered but no need to increase `i` as the
920 * later maps were moved down.
921 */
922 }
923 }
924 /* Add the map. */
925 err = __maps__insert_sorted(maps, i, new, NULL);
926 out_err:
927 return err;
928 }
929
930 int maps__fixup_overlap_and_insert(struct maps *maps, struct map *new)
931 {
932 int err;
933
934 down_write(maps__lock(maps));
935 err = __maps__fixup_overlap_and_insert(maps, new);
936 up_write(maps__lock(maps));
937 return err;
938 }
939
940 int maps__copy_from(struct maps *dest, struct maps *parent)
941 {
942 /* Note, if struct map were immutable then cloning could use ref counts. */
943 struct map **parent_maps_by_address;
944 int err = 0;
945 unsigned int n;
946
947 down_write(maps__lock(dest));
948 down_read(maps__lock(parent));
949
950 parent_maps_by_address = maps__maps_by_address(parent);
951 n = maps__nr_maps(parent);
952 if (maps__nr_maps(dest) == 0) {
953 /* No existing mappings so just copy from parent to avoid reallocs in insert. */
954 unsigned int nr_maps_allocated = RC_CHK_ACCESS(parent)->nr_maps_allocated;
955 struct map **dest_maps_by_address =
956 malloc(nr_maps_allocated * sizeof(struct map *));
957 struct map **dest_maps_by_name = NULL;
958
959 if (!dest_maps_by_address)
960 err = -ENOMEM;
961 else {
962 if (maps__maps_by_name(parent)) {
963 dest_maps_by_name =
964 malloc(nr_maps_allocated * sizeof(struct map *));
965 }
966
967 RC_CHK_ACCESS(dest)->maps_by_address = dest_maps_by_address;
968 RC_CHK_ACCESS(dest)->maps_by_name = dest_maps_by_name;
969 RC_CHK_ACCESS(dest)->nr_maps_allocated = nr_maps_allocated;
970 }
971
972 for (unsigned int i = 0; !err && i < n; i++) {
973 struct map *pos = parent_maps_by_address[i];
974 struct map *new = map__clone(pos);
975
976 if (!new)
977 err = -ENOMEM;
978 else {
979 err = unwind__prepare_access(dest, new, NULL);
980 if (!err) {
981 dest_maps_by_address[i] = new;
982 if (dest_maps_by_name)
983 dest_maps_by_name[i] = map__get(new);
984 RC_CHK_ACCESS(dest)->nr_maps = i + 1;
985 }
986 }
987 if (err)
988 map__put(new);
989 }
990 maps__set_maps_by_address_sorted(dest, maps__maps_by_address_sorted(parent));
991 if (!err) {
992 RC_CHK_ACCESS(dest)->last_search_by_name_idx =
993 RC_CHK_ACCESS(parent)->last_search_by_name_idx;
994 maps__set_maps_by_name_sorted(dest,
995 dest_maps_by_name &&
996 maps__maps_by_name_sorted(parent));
997 } else {
998 RC_CHK_ACCESS(dest)->last_search_by_name_idx = 0;
999 maps__set_maps_by_name_sorted(dest, false);
1000 }
1001 } else {
1002 /* Unexpected copying to a maps containing entries. */
1003 for (unsigned int i = 0; !err && i < n; i++) {
1004 struct map *pos = parent_maps_by_address[i];
1005 struct map *new = map__clone(pos);
1006
1007 if (!new)
1008 err = -ENOMEM;
1009 else {
1010 err = unwind__prepare_access(dest, new, NULL);
1011 if (!err)
1012 err = __maps__insert(dest, new);
1013 }
1014 map__put(new);
1015 }
1016 }
1017 check_invariants(dest);
1018
1019 up_read(maps__lock(parent));
1020 up_write(maps__lock(dest));
1021 return err;
1022 }
1023
1024 static int map__addr_cmp(const void *key, const void *entry)
1025 {
1026 const u64 ip = *(const u64 *)key;
1027 const struct map *map = *(const struct map * const *)entry;
1028
1029 if (ip < map__start(map))
1030 return -1;
1031 if (ip >= map__end(map))
1032 return 1;
1033 return 0;
1034 }
1035
1036 struct map *maps__find(struct maps *maps, u64 ip)
1037 {
1038 struct map *result = NULL;
1039 bool done = false;
1040
1041 /* See locking/sorting note. */
1042 while (!done) {
1043 down_read(maps__lock(maps));
1044 if (maps__maps_by_address_sorted(maps)) {
1045 struct map **mapp =
1046 bsearch(&ip, maps__maps_by_address(maps), maps__nr_maps(maps),
1047 sizeof(*mapp), map__addr_cmp);
1048
1049 if (mapp)
1050 result = map__get(*mapp);
1051 done = true;
1052 }
1053 up_read(maps__lock(maps));
1054 if (!done)
1055 maps__sort_by_address(maps);
1056 }
1057 return result;
1058 }
1059
1060 static int map__strcmp_name(const void *name, const void *b)
1061 {
1062 const struct dso *dso = map__dso(*(const struct map **)b);
1063
1064 return strcmp(name, dso__short_name(dso));
1065 }
1066
1067 struct map *maps__find_by_name(struct maps *maps, const char *name)
1068 {
1069 struct map *result = NULL;
1070 bool done = false;
1071
1072 /* See locking/sorting note. */
1073 while (!done) {
1074 unsigned int i;
1075
1076 down_read(maps__lock(maps));
1077
1078 /* First check last found entry. */
1079 i = RC_CHK_ACCESS(maps)->last_search_by_name_idx;
1080 if (i < maps__nr_maps(maps) && maps__maps_by_name(maps)) {
1081 struct dso *dso = map__dso(maps__maps_by_name(maps)[i]);
1082
1083 if (dso && strcmp(dso__short_name(dso), name) == 0) {
1084 result = map__get(maps__maps_by_name(maps)[i]);
1085 done = true;
1086 }
1087 }
1088
1089 /* Second search sorted array. */
1090 if (!done && maps__maps_by_name_sorted(maps)) {
1091 struct map **mapp =
1092 bsearch(name, maps__maps_by_name(maps), maps__nr_maps(maps),
1093 sizeof(*mapp), map__strcmp_name);
1094
1095 if (mapp) {
1096 result = map__get(*mapp);
1097 i = mapp - maps__maps_by_name(maps);
1098 RC_CHK_ACCESS(maps)->last_search_by_name_idx = i;
1099 }
1100 done = true;
1101 }
1102 up_read(maps__lock(maps));
1103 if (!done) {
1104 /* Sort and retry binary search. */
1105 if (maps__sort_by_name(maps)) {
1106 /*
1107 * Memory allocation failed do linear search
1108 * through address sorted maps.
1109 */
1110 struct map **maps_by_address;
1111 unsigned int n;
1112
1113 down_read(maps__lock(maps));
1114 maps_by_address = maps__maps_by_address(maps);
1115 n = maps__nr_maps(maps);
1116 for (i = 0; i < n; i++) {
1117 struct map *pos = maps_by_address[i];
1118 struct dso *dso = map__dso(pos);
1119
1120 if (dso && strcmp(dso__short_name(dso), name) == 0) {
1121 result = map__get(pos);
1122 break;
1123 }
1124 }
1125 up_read(maps__lock(maps));
1126 done = true;
1127 }
1128 }
1129 }
1130 return result;
1131 }
1132
1133 struct map *maps__find_next_entry(struct maps *maps, struct map *map)
1134 {
1135 unsigned int i;
1136 struct map *result = NULL;
1137
1138 down_read(maps__lock(maps));
1139 i = maps__by_address_index(maps, map);
1140 if (i < maps__nr_maps(maps))
1141 result = map__get(maps__maps_by_address(maps)[i]);
1142
1143 up_read(maps__lock(maps));
1144 return result;
1145 }
1146
1147 void maps__fixup_end(struct maps *maps)
1148 {
1149 struct map **maps_by_address;
1150 unsigned int n;
1151
1152 down_write(maps__lock(maps));
1153 if (!maps__maps_by_address_sorted(maps))
1154 __maps__sort_by_address(maps);
1155
1156 maps_by_address = maps__maps_by_address(maps);
1157 n = maps__nr_maps(maps);
1158 for (unsigned int i = 1; i < n; i++) {
1159 struct map *prev = maps_by_address[i - 1];
1160 struct map *curr = maps_by_address[i];
1161
1162 if (!map__end(prev) || map__end(prev) > map__start(curr))
1163 map__set_end(prev, map__start(curr));
1164 }
1165
1166 /*
1167 * We still haven't the actual symbols, so guess the
1168 * last map final address.
1169 */
1170 if (n > 0 && !map__end(maps_by_address[n - 1]))
1171 map__set_end(maps_by_address[n - 1], ~0ULL);
1172
1173 RC_CHK_ACCESS(maps)->ends_broken = false;
1174 check_invariants(maps);
1175
1176 up_write(maps__lock(maps));
1177 }
1178
1179 /*
1180 * Merges map into maps by splitting the new map within the existing map
1181 * regions.
1182 */
1183 int maps__merge_in(struct maps *kmaps, struct map *new_map)
1184 {
1185 unsigned int first_after_, kmaps__nr_maps;
1186 struct map **kmaps_maps_by_address;
1187 struct map **merged_maps_by_address;
1188 unsigned int merged_nr_maps_allocated;
1189
1190 /* First try under a read lock. */
1191 while (true) {
1192 down_read(maps__lock(kmaps));
1193 if (maps__maps_by_address_sorted(kmaps))
1194 break;
1195
1196 up_read(maps__lock(kmaps));
1197
1198 /* First after binary search requires sorted maps. Sort and try again. */
1199 maps__sort_by_address(kmaps);
1200 }
1201 first_after_ = first_ending_after(kmaps, new_map);
1202 kmaps_maps_by_address = maps__maps_by_address(kmaps);
1203
1204 if (first_after_ >= maps__nr_maps(kmaps) ||
1205 map__start(kmaps_maps_by_address[first_after_]) >= map__end(new_map)) {
1206 /* No overlap so regular insert suffices. */
1207 up_read(maps__lock(kmaps));
1208 return maps__insert(kmaps, new_map);
1209 }
1210 up_read(maps__lock(kmaps));
1211
1212 /* Plain insert with a read-lock failed, try again now with the write lock. */
1213 down_write(maps__lock(kmaps));
1214 if (!maps__maps_by_address_sorted(kmaps))
1215 __maps__sort_by_address(kmaps);
1216
1217 first_after_ = first_ending_after(kmaps, new_map);
1218 kmaps_maps_by_address = maps__maps_by_address(kmaps);
1219 kmaps__nr_maps = maps__nr_maps(kmaps);
1220
1221 if (first_after_ >= kmaps__nr_maps ||
1222 map__start(kmaps_maps_by_address[first_after_]) >= map__end(new_map)) {
1223 /* No overlap so regular insert suffices. */
1224 int ret = __maps__insert(kmaps, new_map);
1225
1226 check_invariants(kmaps);
1227 up_write(maps__lock(kmaps));
1228 return ret;
1229 }
1230 /* Array to merge into, possibly 1 more for the sake of new_map. */
1231 merged_nr_maps_allocated = RC_CHK_ACCESS(kmaps)->nr_maps_allocated;
1232 if (kmaps__nr_maps + 1 == merged_nr_maps_allocated)
1233 merged_nr_maps_allocated++;
1234
1235 merged_maps_by_address = malloc(merged_nr_maps_allocated * sizeof(*merged_maps_by_address));
1236 if (!merged_maps_by_address) {
1237 up_write(maps__lock(kmaps));
1238 return -ENOMEM;
1239 }
1240 maps__set_maps_by_address(kmaps, merged_maps_by_address);
1241 maps__set_maps_by_address_sorted(kmaps, true);
1242 __maps__free_maps_by_name(kmaps);
1243 maps__set_nr_maps_allocated(kmaps, merged_nr_maps_allocated);
1244
1245 /* Copy entries before the new_map that can't overlap. */
1246 for (unsigned int i = 0; i < first_after_; i++)
1247 merged_maps_by_address[i] = map__get(kmaps_maps_by_address[i]);
1248
1249 maps__set_nr_maps(kmaps, first_after_);
1250
1251 /* Add the new map, it will be split when the later overlapping mappings are added. */
1252 __maps__insert(kmaps, new_map);
1253
1254 /* Insert mappings after new_map, splitting new_map in the process. */
1255 for (unsigned int i = first_after_; i < kmaps__nr_maps; i++)
1256 __maps__fixup_overlap_and_insert(kmaps, kmaps_maps_by_address[i]);
1257
1258 /* Copy the maps from merged into kmaps. */
1259 for (unsigned int i = 0; i < kmaps__nr_maps; i++)
1260 map__zput(kmaps_maps_by_address[i]);
1261
1262 free(kmaps_maps_by_address);
1263 check_invariants(kmaps);
1264 up_write(maps__lock(kmaps));
1265 return 0;
1266 }
1267
1268 void maps__load_first(struct maps *maps)
1269 {
1270 down_read(maps__lock(maps));
1271
1272 if (maps__nr_maps(maps) > 0)
1273 map__load(maps__maps_by_address(maps)[0]);
1274
1275 up_read(maps__lock(maps));
1276 }
1277
Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.