1 // SPDX-License-Identifier: GPL-2.0
2 #include <inttypes.h>
3 #include <limits.h>
4 #include <stdio.h>
5 #include <stdlib.h>
6 #include <string.h>
7 #include <linux/string.h>
8 #include <linux/zalloc.h>
9 #include <uapi/linux/mman.h> /* To get things like MAP_HUGETLB even on older libc headers */
10 #include "debug.h"
11 #include "dso.h"
12 #include "map.h"
13 #include "namespaces.h"
14 #include "srcline.h"
15 #include "symbol.h"
16 #include "thread.h"
17 #include "vdso.h"
18 
is_android_lib(const char * filename)19 static inline int is_android_lib(const char *filename)
20 {
21 	return strstarts(filename, "/data/app-lib/") ||
22 	       strstarts(filename, "/system/lib/");
23 }
24 
replace_android_lib(const char * filename,char * newfilename)25 static inline bool replace_android_lib(const char *filename, char *newfilename)
26 {
27 	const char *libname;
28 	char *app_abi;
29 	size_t app_abi_length, new_length;
30 	size_t lib_length = 0;
31 
32 	libname  = strrchr(filename, '/');
33 	if (libname)
34 		lib_length = strlen(libname);
35 
36 	app_abi = getenv("APP_ABI");
37 	if (!app_abi)
38 		return false;
39 
40 	app_abi_length = strlen(app_abi);
41 
42 	if (strstarts(filename, "/data/app-lib/")) {
43 		char *apk_path;
44 
45 		if (!app_abi_length)
46 			return false;
47 
48 		new_length = 7 + app_abi_length + lib_length;
49 
50 		apk_path = getenv("APK_PATH");
51 		if (apk_path) {
52 			new_length += strlen(apk_path) + 1;
53 			if (new_length > PATH_MAX)
54 				return false;
55 			snprintf(newfilename, new_length,
56 				 "%s/libs/%s/%s", apk_path, app_abi, libname);
57 		} else {
58 			if (new_length > PATH_MAX)
59 				return false;
60 			snprintf(newfilename, new_length,
61 				 "libs/%s/%s", app_abi, libname);
62 		}
63 		return true;
64 	}
65 
66 	if (strstarts(filename, "/system/lib/")) {
67 		char *ndk, *app;
68 		const char *arch;
69 		int ndk_length, app_length;
70 
71 		ndk = getenv("NDK_ROOT");
72 		app = getenv("APP_PLATFORM");
73 
74 		if (!(ndk && app))
75 			return false;
76 
77 		ndk_length = strlen(ndk);
78 		app_length = strlen(app);
79 
80 		if (!(ndk_length && app_length && app_abi_length))
81 			return false;
82 
83 		arch = !strncmp(app_abi, "arm", 3) ? "arm" :
84 		       !strncmp(app_abi, "mips", 4) ? "mips" :
85 		       !strncmp(app_abi, "x86", 3) ? "x86" : NULL;
86 
87 		if (!arch)
88 			return false;
89 
90 		new_length = 27 + ndk_length +
91 			     app_length + lib_length
92 			   + strlen(arch);
93 
94 		if (new_length > PATH_MAX)
95 			return false;
96 		snprintf(newfilename, new_length,
97 			"%.*s/platforms/%.*s/arch-%s/usr/lib/%s",
98 			ndk_length, ndk, app_length, app, arch, libname);
99 
100 		return true;
101 	}
102 	return false;
103 }
104 
map__init(struct map * map,u64 start,u64 end,u64 pgoff,struct dso * dso)105 void map__init(struct map *map, u64 start, u64 end, u64 pgoff, struct dso *dso)
106 {
107 	map__set_start(map, start);
108 	map__set_end(map, end);
109 	map__set_pgoff(map, pgoff);
110 	map__set_reloc(map, 0);
111 	map__set_dso(map, dso__get(dso));
112 	map__set_map_ip(map, map__dso_map_ip);
113 	map__set_unmap_ip(map, map__dso_unmap_ip);
114 	map__set_erange_warned(map, false);
115 	refcount_set(map__refcnt(map), 1);
116 }
117 
map__new(struct machine * machine,u64 start,u64 len,u64 pgoff,struct dso_id * id,u32 prot,u32 flags,struct build_id * bid,char * filename,struct thread * thread)118 struct map *map__new(struct machine *machine, u64 start, u64 len,
119 		     u64 pgoff, struct dso_id *id,
120 		     u32 prot, u32 flags, struct build_id *bid,
121 		     char *filename, struct thread *thread)
122 {
123 	struct map *result;
124 	RC_STRUCT(map) *map;
125 	struct nsinfo *nsi = NULL;
126 	struct nsinfo *nnsi;
127 
128 	map = malloc(sizeof(*map));
129 	if (ADD_RC_CHK(result, map)) {
130 		char newfilename[PATH_MAX];
131 		struct dso *dso, *header_bid_dso;
132 		int anon, no_dso, vdso, android;
133 
134 		android = is_android_lib(filename);
135 		anon = is_anon_memory(filename) || flags & MAP_HUGETLB;
136 		vdso = is_vdso_map(filename);
137 		no_dso = is_no_dso_memory(filename);
138 		map->prot = prot;
139 		map->flags = flags;
140 		nsi = nsinfo__get(thread__nsinfo(thread));
141 
142 		if ((anon || no_dso) && nsi && (prot & PROT_EXEC)) {
143 			snprintf(newfilename, sizeof(newfilename),
144 				 "/tmp/perf-%d.map", nsinfo__pid(nsi));
145 			filename = newfilename;
146 		}
147 
148 		if (android) {
149 			if (replace_android_lib(filename, newfilename))
150 				filename = newfilename;
151 		}
152 
153 		if (vdso) {
154 			/* The vdso maps are always on the host and not the
155 			 * container.  Ensure that we don't use setns to look
156 			 * them up.
157 			 */
158 			nnsi = nsinfo__copy(nsi);
159 			if (nnsi) {
160 				nsinfo__put(nsi);
161 				nsinfo__clear_need_setns(nnsi);
162 				nsi = nnsi;
163 			}
164 			pgoff = 0;
165 			dso = machine__findnew_vdso(machine, thread);
166 		} else
167 			dso = machine__findnew_dso_id(machine, filename, id);
168 
169 		if (dso == NULL)
170 			goto out_delete;
171 
172 		map__init(result, start, start + len, pgoff, dso);
173 
174 		if (anon || no_dso) {
175 			map->map_ip = map->unmap_ip = identity__map_ip;
176 
177 			/*
178 			 * Set memory without DSO as loaded. All map__find_*
179 			 * functions still return NULL, and we avoid the
180 			 * unnecessary map__load warning.
181 			 */
182 			if (!(prot & PROT_EXEC))
183 				dso__set_loaded(dso);
184 		}
185 		mutex_lock(&dso->lock);
186 		nsinfo__put(dso->nsinfo);
187 		dso->nsinfo = nsi;
188 		mutex_unlock(&dso->lock);
189 
190 		if (build_id__is_defined(bid)) {
191 			dso__set_build_id(dso, bid);
192 		} else {
193 			/*
194 			 * If the mmap event had no build ID, search for an existing dso from the
195 			 * build ID header by name. Otherwise only the dso loaded at the time of
196 			 * reading the header will have the build ID set and all future mmaps will
197 			 * have it missing.
198 			 */
199 			down_read(&machine->dsos.lock);
200 			header_bid_dso = __dsos__find(&machine->dsos, filename, false);
201 			up_read(&machine->dsos.lock);
202 			if (header_bid_dso && header_bid_dso->header_build_id) {
203 				dso__set_build_id(dso, &header_bid_dso->bid);
204 				dso->header_build_id = 1;
205 			}
206 		}
207 		dso__put(dso);
208 	}
209 	return result;
210 out_delete:
211 	nsinfo__put(nsi);
212 	RC_CHK_FREE(result);
213 	return NULL;
214 }
215 
216 /*
217  * Constructor variant for modules (where we know from /proc/modules where
218  * they are loaded) and for vmlinux, where only after we load all the
219  * symbols we'll know where it starts and ends.
220  */
map__new2(u64 start,struct dso * dso)221 struct map *map__new2(u64 start, struct dso *dso)
222 {
223 	struct map *result;
224 	RC_STRUCT(map) *map;
225 
226 	map = calloc(1, sizeof(*map) + (dso->kernel ? sizeof(struct kmap) : 0));
227 	if (ADD_RC_CHK(result, map)) {
228 		/*
229 		 * ->end will be filled after we load all the symbols
230 		 */
231 		map__init(result, start, 0, 0, dso);
232 	}
233 
234 	return result;
235 }
236 
__map__is_kernel(const struct map * map)237 bool __map__is_kernel(const struct map *map)
238 {
239 	if (!map__dso(map)->kernel)
240 		return false;
241 	return machine__kernel_map(maps__machine(map__kmaps((struct map *)map))) == map;
242 }
243 
__map__is_extra_kernel_map(const struct map * map)244 bool __map__is_extra_kernel_map(const struct map *map)
245 {
246 	struct kmap *kmap = __map__kmap((struct map *)map);
247 
248 	return kmap && kmap->name[0];
249 }
250 
__map__is_bpf_prog(const struct map * map)251 bool __map__is_bpf_prog(const struct map *map)
252 {
253 	const char *name;
254 	struct dso *dso = map__dso(map);
255 
256 	if (dso->binary_type == DSO_BINARY_TYPE__BPF_PROG_INFO)
257 		return true;
258 
259 	/*
260 	 * If PERF_RECORD_BPF_EVENT is not included, the dso will not have
261 	 * type of DSO_BINARY_TYPE__BPF_PROG_INFO. In such cases, we can
262 	 * guess the type based on name.
263 	 */
264 	name = dso->short_name;
265 	return name && (strstr(name, "bpf_prog_") == name);
266 }
267 
__map__is_bpf_image(const struct map * map)268 bool __map__is_bpf_image(const struct map *map)
269 {
270 	const char *name;
271 	struct dso *dso = map__dso(map);
272 
273 	if (dso->binary_type == DSO_BINARY_TYPE__BPF_IMAGE)
274 		return true;
275 
276 	/*
277 	 * If PERF_RECORD_KSYMBOL is not included, the dso will not have
278 	 * type of DSO_BINARY_TYPE__BPF_IMAGE. In such cases, we can
279 	 * guess the type based on name.
280 	 */
281 	name = dso->short_name;
282 	return name && is_bpf_image(name);
283 }
284 
__map__is_ool(const struct map * map)285 bool __map__is_ool(const struct map *map)
286 {
287 	const struct dso *dso = map__dso(map);
288 
289 	return dso && dso->binary_type == DSO_BINARY_TYPE__OOL;
290 }
291 
map__has_symbols(const struct map * map)292 bool map__has_symbols(const struct map *map)
293 {
294 	return dso__has_symbols(map__dso(map));
295 }
296 
map__exit(struct map * map)297 static void map__exit(struct map *map)
298 {
299 	BUG_ON(refcount_read(map__refcnt(map)) != 0);
300 	dso__zput(RC_CHK_ACCESS(map)->dso);
301 }
302 
map__delete(struct map * map)303 void map__delete(struct map *map)
304 {
305 	map__exit(map);
306 	RC_CHK_FREE(map);
307 }
308 
map__put(struct map * map)309 void map__put(struct map *map)
310 {
311 	if (map && refcount_dec_and_test(map__refcnt(map)))
312 		map__delete(map);
313 	else
314 		RC_CHK_PUT(map);
315 }
316 
map__fixup_start(struct map * map)317 void map__fixup_start(struct map *map)
318 {
319 	struct dso *dso = map__dso(map);
320 	struct rb_root_cached *symbols = &dso->symbols;
321 	struct rb_node *nd = rb_first_cached(symbols);
322 
323 	if (nd != NULL) {
324 		struct symbol *sym = rb_entry(nd, struct symbol, rb_node);
325 
326 		map__set_start(map, sym->start);
327 	}
328 }
329 
map__fixup_end(struct map * map)330 void map__fixup_end(struct map *map)
331 {
332 	struct dso *dso = map__dso(map);
333 	struct rb_root_cached *symbols = &dso->symbols;
334 	struct rb_node *nd = rb_last(&symbols->rb_root);
335 
336 	if (nd != NULL) {
337 		struct symbol *sym = rb_entry(nd, struct symbol, rb_node);
338 		map__set_end(map, sym->end);
339 	}
340 }
341 
342 #define DSO__DELETED "(deleted)"
343 
map__load(struct map * map)344 int map__load(struct map *map)
345 {
346 	struct dso *dso = map__dso(map);
347 	const char *name = dso->long_name;
348 	int nr;
349 
350 	if (dso__loaded(dso))
351 		return 0;
352 
353 	nr = dso__load(dso, map);
354 	if (nr < 0) {
355 		if (dso->has_build_id) {
356 			char sbuild_id[SBUILD_ID_SIZE];
357 
358 			build_id__sprintf(&dso->bid, sbuild_id);
359 			pr_debug("%s with build id %s not found", name, sbuild_id);
360 		} else
361 			pr_debug("Failed to open %s", name);
362 
363 		pr_debug(", continuing without symbols\n");
364 		return -1;
365 	} else if (nr == 0) {
366 #ifdef HAVE_LIBELF_SUPPORT
367 		const size_t len = strlen(name);
368 		const size_t real_len = len - sizeof(DSO__DELETED);
369 
370 		if (len > sizeof(DSO__DELETED) &&
371 		    strcmp(name + real_len + 1, DSO__DELETED) == 0) {
372 			pr_debug("%.*s was updated (is prelink enabled?). "
373 				"Restart the long running apps that use it!\n",
374 				   (int)real_len, name);
375 		} else {
376 			pr_debug("no symbols found in %s, maybe install a debug package?\n", name);
377 		}
378 #endif
379 		return -1;
380 	}
381 
382 	return 0;
383 }
384 
map__find_symbol(struct map * map,u64 addr)385 struct symbol *map__find_symbol(struct map *map, u64 addr)
386 {
387 	if (map__load(map) < 0)
388 		return NULL;
389 
390 	return dso__find_symbol(map__dso(map), addr);
391 }
392 
map__find_symbol_by_name_idx(struct map * map,const char * name,size_t * idx)393 struct symbol *map__find_symbol_by_name_idx(struct map *map, const char *name, size_t *idx)
394 {
395 	struct dso *dso;
396 
397 	if (map__load(map) < 0)
398 		return NULL;
399 
400 	dso = map__dso(map);
401 	dso__sort_by_name(dso);
402 
403 	return dso__find_symbol_by_name(dso, name, idx);
404 }
405 
map__find_symbol_by_name(struct map * map,const char * name)406 struct symbol *map__find_symbol_by_name(struct map *map, const char *name)
407 {
408 	size_t idx;
409 
410 	return map__find_symbol_by_name_idx(map, name, &idx);
411 }
412 
map__clone(struct map * from)413 struct map *map__clone(struct map *from)
414 {
415 	struct map *result;
416 	RC_STRUCT(map) *map;
417 	size_t size = sizeof(RC_STRUCT(map));
418 	struct dso *dso = map__dso(from);
419 
420 	if (dso && dso->kernel)
421 		size += sizeof(struct kmap);
422 
423 	map = memdup(RC_CHK_ACCESS(from), size);
424 	if (ADD_RC_CHK(result, map)) {
425 		refcount_set(&map->refcnt, 1);
426 		map->dso = dso__get(dso);
427 	}
428 
429 	return result;
430 }
431 
map__fprintf(struct map * map,FILE * fp)432 size_t map__fprintf(struct map *map, FILE *fp)
433 {
434 	const struct dso *dso = map__dso(map);
435 
436 	return fprintf(fp, " %" PRIx64 "-%" PRIx64 " %" PRIx64 " %s\n",
437 		       map__start(map), map__end(map), map__pgoff(map), dso->name);
438 }
439 
prefer_dso_long_name(const struct dso * dso,bool print_off)440 static bool prefer_dso_long_name(const struct dso *dso, bool print_off)
441 {
442 	return dso->long_name &&
443 	       (symbol_conf.show_kernel_path ||
444 		(print_off && (dso->name[0] == '[' || dso__is_kcore(dso))));
445 }
446 
__map__fprintf_dsoname(struct map * map,bool print_off,FILE * fp)447 static size_t __map__fprintf_dsoname(struct map *map, bool print_off, FILE *fp)
448 {
449 	char buf[symbol_conf.pad_output_len_dso + 1];
450 	const char *dsoname = "[unknown]";
451 	const struct dso *dso = map ? map__dso(map) : NULL;
452 
453 	if (dso) {
454 		if (prefer_dso_long_name(dso, print_off))
455 			dsoname = dso->long_name;
456 		else
457 			dsoname = dso->name;
458 	}
459 
460 	if (symbol_conf.pad_output_len_dso) {
461 		scnprintf_pad(buf, symbol_conf.pad_output_len_dso, "%s", dsoname);
462 		dsoname = buf;
463 	}
464 
465 	return fprintf(fp, "%s", dsoname);
466 }
467 
map__fprintf_dsoname(struct map * map,FILE * fp)468 size_t map__fprintf_dsoname(struct map *map, FILE *fp)
469 {
470 	return __map__fprintf_dsoname(map, false, fp);
471 }
472 
map__fprintf_dsoname_dsoff(struct map * map,bool print_off,u64 addr,FILE * fp)473 size_t map__fprintf_dsoname_dsoff(struct map *map, bool print_off, u64 addr, FILE *fp)
474 {
475 	const struct dso *dso = map ? map__dso(map) : NULL;
476 	int printed = 0;
477 
478 	if (print_off && (!dso || !dso__is_object_file(dso)))
479 		print_off = false;
480 	printed += fprintf(fp, " (");
481 	printed += __map__fprintf_dsoname(map, print_off, fp);
482 	if (print_off)
483 		printed += fprintf(fp, "+0x%" PRIx64, addr);
484 	printed += fprintf(fp, ")");
485 
486 	return printed;
487 }
488 
map__srcline(struct map * map,u64 addr,struct symbol * sym)489 char *map__srcline(struct map *map, u64 addr, struct symbol *sym)
490 {
491 	if (map == NULL)
492 		return SRCLINE_UNKNOWN;
493 
494 	return get_srcline(map__dso(map), map__rip_2objdump(map, addr), sym, true, true, addr);
495 }
496 
map__fprintf_srcline(struct map * map,u64 addr,const char * prefix,FILE * fp)497 int map__fprintf_srcline(struct map *map, u64 addr, const char *prefix,
498 			 FILE *fp)
499 {
500 	const struct dso *dso = map ? map__dso(map) : NULL;
501 	int ret = 0;
502 
503 	if (dso) {
504 		char *srcline = map__srcline(map, addr, NULL);
505 		if (srcline != SRCLINE_UNKNOWN)
506 			ret = fprintf(fp, "%s%s", prefix, srcline);
507 		zfree_srcline(&srcline);
508 	}
509 	return ret;
510 }
511 
srccode_state_free(struct srccode_state * state)512 void srccode_state_free(struct srccode_state *state)
513 {
514 	zfree(&state->srcfile);
515 	state->line = 0;
516 }
517 
518 /**
519  * map__rip_2objdump - convert symbol start address to objdump address.
520  * @map: memory map
521  * @rip: symbol start address
522  *
523  * objdump wants/reports absolute IPs for ET_EXEC, and RIPs for ET_DYN.
524  * map->dso->adjust_symbols==1 for ET_EXEC-like cases except ET_REL which is
525  * relative to section start.
526  *
527  * Return: Address suitable for passing to "objdump --start-address="
528  */
map__rip_2objdump(struct map * map,u64 rip)529 u64 map__rip_2objdump(struct map *map, u64 rip)
530 {
531 	struct kmap *kmap = __map__kmap(map);
532 	const struct dso *dso = map__dso(map);
533 
534 	/*
535 	 * vmlinux does not have program headers for PTI entry trampolines and
536 	 * kcore may not either. However the trampoline object code is on the
537 	 * main kernel map, so just use that instead.
538 	 */
539 	if (kmap && is_entry_trampoline(kmap->name) && kmap->kmaps) {
540 		struct machine *machine = maps__machine(kmap->kmaps);
541 
542 		if (machine) {
543 			struct map *kernel_map = machine__kernel_map(machine);
544 
545 			if (kernel_map)
546 				map = kernel_map;
547 		}
548 	}
549 
550 	if (!dso->adjust_symbols)
551 		return rip;
552 
553 	if (dso->rel)
554 		return rip - map__pgoff(map);
555 
556 	/*
557 	 * kernel modules also have DSO_TYPE_USER in dso->kernel,
558 	 * but all kernel modules are ET_REL, so won't get here.
559 	 */
560 	if (dso->kernel == DSO_SPACE__USER)
561 		return rip + dso->text_offset;
562 
563 	return map__unmap_ip(map, rip) - map__reloc(map);
564 }
565 
566 /**
567  * map__objdump_2mem - convert objdump address to a memory address.
568  * @map: memory map
569  * @ip: objdump address
570  *
571  * Closely related to map__rip_2objdump(), this function takes an address from
572  * objdump and converts it to a memory address.  Note this assumes that @map
573  * contains the address.  To be sure the result is valid, check it forwards
574  * e.g. map__rip_2objdump(map__map_ip(map, map__objdump_2mem(map, ip))) == ip
575  *
576  * Return: Memory address.
577  */
map__objdump_2mem(struct map * map,u64 ip)578 u64 map__objdump_2mem(struct map *map, u64 ip)
579 {
580 	const struct dso *dso = map__dso(map);
581 
582 	if (!dso->adjust_symbols)
583 		return map__unmap_ip(map, ip);
584 
585 	if (dso->rel)
586 		return map__unmap_ip(map, ip + map__pgoff(map));
587 
588 	/*
589 	 * kernel modules also have DSO_TYPE_USER in dso->kernel,
590 	 * but all kernel modules are ET_REL, so won't get here.
591 	 */
592 	if (dso->kernel == DSO_SPACE__USER)
593 		return map__unmap_ip(map, ip - dso->text_offset);
594 
595 	return ip + map__reloc(map);
596 }
597 
map__contains_symbol(const struct map * map,const struct symbol * sym)598 bool map__contains_symbol(const struct map *map, const struct symbol *sym)
599 {
600 	u64 ip = map__unmap_ip(map, sym->start);
601 
602 	return ip >= map__start(map) && ip < map__end(map);
603 }
604 
__map__kmap(struct map * map)605 struct kmap *__map__kmap(struct map *map)
606 {
607 	const struct dso *dso = map__dso(map);
608 
609 	if (!dso || !dso->kernel)
610 		return NULL;
611 	return (struct kmap *)(&RC_CHK_ACCESS(map)[1]);
612 }
613 
map__kmap(struct map * map)614 struct kmap *map__kmap(struct map *map)
615 {
616 	struct kmap *kmap = __map__kmap(map);
617 
618 	if (!kmap)
619 		pr_err("Internal error: map__kmap with a non-kernel map\n");
620 	return kmap;
621 }
622 
map__kmaps(struct map * map)623 struct maps *map__kmaps(struct map *map)
624 {
625 	struct kmap *kmap = map__kmap(map);
626 
627 	if (!kmap || !kmap->kmaps) {
628 		pr_err("Internal error: map__kmaps with a non-kernel map\n");
629 		return NULL;
630 	}
631 	return kmap->kmaps;
632 }
633 
map__dso_map_ip(const struct map * map,u64 ip)634 u64 map__dso_map_ip(const struct map *map, u64 ip)
635 {
636 	return ip - map__start(map) + map__pgoff(map);
637 }
638 
map__dso_unmap_ip(const struct map * map,u64 ip)639 u64 map__dso_unmap_ip(const struct map *map, u64 ip)
640 {
641 	return ip + map__start(map) - map__pgoff(map);
642 }
643 
identity__map_ip(const struct map * map __maybe_unused,u64 ip)644 u64 identity__map_ip(const struct map *map __maybe_unused, u64 ip)
645 {
646 	return ip;
647 }
648