map.c

  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
 19static inline int is_android_lib(const char *filename)
 20{
 21	return strstarts(filename, "/data/app-lib/") ||
 22	       strstarts(filename, "/system/lib/");
 23}
 24
 25static 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
105static void map__init(struct map *map, u64 start, u64 end, u64 pgoff,
106		      struct dso *dso, u32 prot, u32 flags)
107{
108	map__set_start(map, start);
109	map__set_end(map, end);
110	map__set_pgoff(map, pgoff);
111	assert(map__reloc(map) == 0);
112	map__set_dso(map, dso__get(dso));
113	refcount_set(map__refcnt(map), 1);
114	RC_CHK_ACCESS(map)->prot = prot;
115	RC_CHK_ACCESS(map)->flags = flags;
116	map__set_mapping_type(map, MAPPING_TYPE__DSO);
117	assert(map__erange_warned(map) == false);
118	assert(map__priv(map) == false);
119	assert(map__hit(map) == false);
120}
121
122struct map *map__new(struct machine *machine, u64 start, u64 len,
123		     u64 pgoff, const struct dso_id *id,
124		     u32 prot, u32 flags,
125		     char *filename, struct thread *thread)
126{
127	struct map *result;
128	RC_STRUCT(map) *map;
129	struct nsinfo *nsi = NULL;
130	struct nsinfo *nnsi;
131
132	map = zalloc(sizeof(*map));
133	if (ADD_RC_CHK(result, map)) {
134		char newfilename[PATH_MAX];
135		struct dso *dso;
136		int anon, no_dso, vdso, android;
137
138		android = is_android_lib(filename);
139		anon = is_anon_memory(filename) || flags & MAP_HUGETLB;
140		vdso = is_vdso_map(filename);
141		no_dso = is_no_dso_memory(filename);
142		nsi = nsinfo__get(thread__nsinfo(thread));
143
144		if ((anon || no_dso) && nsi && (prot & PROT_EXEC)) {
145			snprintf(newfilename, sizeof(newfilename),
146				 "/tmp/perf-%d.map", nsinfo__pid(nsi));
147			filename = newfilename;
148		}
149
150		if (android) {
151			if (replace_android_lib(filename, newfilename))
152				filename = newfilename;
153		}
154
155		if (vdso) {
156			/* The vdso maps are always on the host and not the
157			 * container.  Ensure that we don't use setns to look
158			 * them up.
159			 */
160			nnsi = nsinfo__copy(nsi);
161			if (nnsi) {
162				nsinfo__put(nsi);
163				nsinfo__clear_need_setns(nnsi);
164				nsi = nnsi;
165			}
166			pgoff = 0;
167			dso = machine__findnew_vdso(machine, thread);
168		} else
169			dso = machine__findnew_dso_id(machine, filename, id);
170
171		if (dso == NULL)
172			goto out_delete;
173
174		assert(!dso__kernel(dso));
175		map__init(result, start, start + len, pgoff, dso, prot, flags);
176
177		if (anon || no_dso) {
178			map->mapping_type = MAPPING_TYPE__IDENTITY;
179
180			/*
181			 * Set memory without DSO as loaded. All map__find_*
182			 * functions still return NULL, and we avoid the
183			 * unnecessary map__load warning.
184			 */
185			if (!(prot & PROT_EXEC))
186				dso__set_loaded(dso);
187		}
188		mutex_lock(dso__lock(dso));
189		dso__set_nsinfo(dso, nsi);
190		mutex_unlock(dso__lock(dso));
191
192		if (!build_id__is_defined(&id->build_id)) {
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			struct dso *header_bid_dso = dsos__find(&machine->dsos, filename, false);
200
201			if (header_bid_dso && dso__header_build_id(header_bid_dso)) {
202				dso__set_build_id(dso, dso__bid(header_bid_dso));
203				dso__set_header_build_id(dso, 1);
204			}
205			dso__put(header_bid_dso);
206		}
207		dso__put(dso);
208	}
209	return result;
210out_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 */
221struct 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(dso) ? sizeof(struct kmap) : 0));
227	if (ADD_RC_CHK(result, map)) {
228		/* ->end will be filled after we load all the symbols. */
229		map__init(result, start, /*end=*/0, /*pgoff=*/0, dso, /*prot=*/0, /*flags=*/0);
230	}
231
232	return result;
233}
234
235bool __map__is_kernel(const struct map *map)
236{
237	if (!dso__kernel(map__dso(map)))
238		return false;
239	return machine__kernel_map(maps__machine(map__kmaps((struct map *)map))) == map;
240}
241
242bool __map__is_extra_kernel_map(const struct map *map)
243{
244	struct kmap *kmap = __map__kmap((struct map *)map);
245
246	return kmap && kmap->name[0];
247}
248
249bool __map__is_bpf_prog(const struct map *map)
250{
251	const char *name;
252	struct dso *dso = map__dso(map);
253
254	if (dso__binary_type(dso) == DSO_BINARY_TYPE__BPF_PROG_INFO)
255		return true;
256
257	/*
258	 * If PERF_RECORD_BPF_EVENT is not included, the dso will not have
259	 * type of DSO_BINARY_TYPE__BPF_PROG_INFO. In such cases, we can
260	 * guess the type based on name.
261	 */
262	name = dso__short_name(dso);
263	return name && (strstr(name, "bpf_prog_") == name);
264}
265
266bool __map__is_bpf_image(const struct map *map)
267{
268	const char *name;
269	struct dso *dso = map__dso(map);
270
271	if (dso__binary_type(dso) == DSO_BINARY_TYPE__BPF_IMAGE)
272		return true;
273
274	/*
275	 * If PERF_RECORD_KSYMBOL is not included, the dso will not have
276	 * type of DSO_BINARY_TYPE__BPF_IMAGE. In such cases, we can
277	 * guess the type based on name.
278	 */
279	name = dso__short_name(dso);
280	return name && is_bpf_image(name);
281}
282
283bool __map__is_ool(const struct map *map)
284{
285	const struct dso *dso = map__dso(map);
286
287	return dso && dso__binary_type(dso) == DSO_BINARY_TYPE__OOL;
288}
289
290bool map__has_symbols(const struct map *map)
291{
292	return dso__has_symbols(map__dso(map));
293}
294
295static void map__exit(struct map *map)
296{
297	BUG_ON(refcount_read(map__refcnt(map)) != 0);
298	dso__zput(RC_CHK_ACCESS(map)->dso);
299}
300
301void map__delete(struct map *map)
302{
303	map__exit(map);
304	RC_CHK_FREE(map);
305}
306
307void map__put(struct map *map)
308{
309	if (map && refcount_dec_and_test(map__refcnt(map)))
310		map__delete(map);
311	else
312		RC_CHK_PUT(map);
313}
314
315void map__fixup_start(struct map *map)
316{
317	struct dso *dso = map__dso(map);
318	struct rb_root_cached *symbols = dso__symbols(dso);
319	struct rb_node *nd = rb_first_cached(symbols);
320
321	if (nd != NULL) {
322		struct symbol *sym = rb_entry(nd, struct symbol, rb_node);
323
324		map__set_start(map, sym->start);
325	}
326}
327
328void map__fixup_end(struct map *map)
329{
330	struct dso *dso = map__dso(map);
331	struct rb_root_cached *symbols = dso__symbols(dso);
332	struct rb_node *nd = rb_last(&symbols->rb_root);
333
334	if (nd != NULL) {
335		struct symbol *sym = rb_entry(nd, struct symbol, rb_node);
336		map__set_end(map, sym->end);
337	}
338}
339
340#define DSO__DELETED "(deleted)"
341
342int map__load(struct map *map)
343{
344	struct dso *dso = map__dso(map);
345	const char *name = dso__long_name(dso);
346	int nr;
347
348	if (dso__loaded(dso))
349		return 0;
350
351	nr = dso__load(dso, map);
352	if (nr < 0) {
353		if (dso__has_build_id(dso)) {
354			char sbuild_id[SBUILD_ID_SIZE];
355
356			build_id__snprintf(dso__bid(dso), sbuild_id, sizeof(sbuild_id));
357			pr_debug("%s with build id %s not found", name, sbuild_id);
358		} else
359			pr_debug("Failed to open %s", name);
360
361		pr_debug(", continuing without symbols\n");
362		return -1;
363	} else if (nr == 0) {
364#ifdef HAVE_LIBELF_SUPPORT
365		const size_t len = strlen(name);
366		const size_t real_len = len - sizeof(DSO__DELETED);
367
368		if (len > sizeof(DSO__DELETED) &&
369		    strcmp(name + real_len + 1, DSO__DELETED) == 0) {
370			pr_debug("%.*s was updated (is prelink enabled?). "
371				"Restart the long running apps that use it!\n",
372				   (int)real_len, name);
373		} else {
374			pr_debug("no symbols found in %s, maybe install a debug package?\n", name);
375		}
376#endif
377		return -1;
378	}
379
380	return 0;
381}
382
383struct symbol *map__find_symbol(struct map *map, u64 addr)
384{
385	if (map__load(map) < 0)
386		return NULL;
387
388	return dso__find_symbol(map__dso(map), addr);
389}
390
391struct symbol *map__find_symbol_by_name_idx(struct map *map, const char *name, size_t *idx)
392{
393	struct dso *dso;
394
395	if (map__load(map) < 0)
396		return NULL;
397
398	dso = map__dso(map);
399	dso__sort_by_name(dso);
400
401	return dso__find_symbol_by_name(dso, name, idx);
402}
403
404struct symbol *map__find_symbol_by_name(struct map *map, const char *name)
405{
406	size_t idx;
407
408	return map__find_symbol_by_name_idx(map, name, &idx);
409}
410
411struct map *map__clone(struct map *from)
412{
413	struct map *result;
414	RC_STRUCT(map) *map;
415	size_t size = sizeof(RC_STRUCT(map));
416	struct dso *dso = map__dso(from);
417
418	if (dso && dso__kernel(dso))
419		size += sizeof(struct kmap);
420
421	map = memdup(RC_CHK_ACCESS(from), size);
422	if (ADD_RC_CHK(result, map)) {
423		refcount_set(&map->refcnt, 1);
424		map->dso = dso__get(dso);
425	}
426
427	return result;
428}
429
430size_t map__fprintf(struct map *map, FILE *fp)
431{
432	const struct dso *dso = map__dso(map);
433
434	return fprintf(fp, " %" PRIx64 "-%" PRIx64 " %" PRIx64 " %s\n",
435		       map__start(map), map__end(map), map__pgoff(map), dso__name(dso));
436}
437
438static bool prefer_dso_long_name(const struct dso *dso, bool print_off)
439{
440	return dso__long_name(dso) &&
441	       (symbol_conf.show_kernel_path ||
442		(print_off && (dso__name(dso)[0] == '[' || dso__is_kcore(dso))));
443}
444
445static size_t __map__fprintf_dsoname(struct map *map, bool print_off, FILE *fp)
446{
447	char buf[symbol_conf.pad_output_len_dso + 1];
448	const char *dsoname = "[unknown]";
449	const struct dso *dso = map ? map__dso(map) : NULL;
450
451	if (dso) {
452		if (prefer_dso_long_name(dso, print_off))
453			dsoname = dso__long_name(dso);
454		else
455			dsoname = dso__name(dso);
456	}
457
458	if (symbol_conf.pad_output_len_dso) {
459		scnprintf_pad(buf, symbol_conf.pad_output_len_dso, "%s", dsoname);
460		dsoname = buf;
461	}
462
463	return fprintf(fp, "%s", dsoname);
464}
465
466size_t map__fprintf_dsoname(struct map *map, FILE *fp)
467{
468	return __map__fprintf_dsoname(map, false, fp);
469}
470
471size_t map__fprintf_dsoname_dsoff(struct map *map, bool print_off, u64 addr, FILE *fp)
472{
473	const struct dso *dso = map ? map__dso(map) : NULL;
474	int printed = 0;
475
476	if (print_off && (!dso || !dso__is_object_file(dso)))
477		print_off = false;
478	printed += fprintf(fp, " (");
479	printed += __map__fprintf_dsoname(map, print_off, fp);
480	if (print_off)
481		printed += fprintf(fp, "+0x%" PRIx64, addr);
482	printed += fprintf(fp, ")");
483
484	return printed;
485}
486
487char *map__srcline(struct map *map, u64 addr, struct symbol *sym)
488{
489	if (map == NULL)
490		return SRCLINE_UNKNOWN;
491
492	return get_srcline(map__dso(map), map__rip_2objdump(map, addr), sym, true, true, addr);
493}
494
495int map__fprintf_srcline(struct map *map, u64 addr, const char *prefix,
496			 FILE *fp)
497{
498	const struct dso *dso = map ? map__dso(map) : NULL;
499	int ret = 0;
500
501	if (dso) {
502		char *srcline = map__srcline(map, addr, NULL);
503		if (srcline != SRCLINE_UNKNOWN)
504			ret = fprintf(fp, "%s%s", prefix, srcline);
505		zfree_srcline(&srcline);
506	}
507	return ret;
508}
509
510void srccode_state_free(struct srccode_state *state)
511{
512	zfree(&state->srcfile);
513	state->line = 0;
514}
515
516static const struct kmap *__map__const_kmap(const struct map *map);
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 */
529u64 map__rip_2objdump(const struct map *map, u64 rip)
530{
531	const struct kmap *kmap = __map__const_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(dso))
551		return rip;
552
553	if (dso__rel(dso))
554		return rip - map__pgoff(map);
555
556	if (dso__kernel(dso) == DSO_SPACE__USER)
557		return rip + dso__text_offset(dso);
558
559	return map__unmap_ip(map, rip) - map__reloc(map);
560}
561
562/**
563 * map__objdump_2mem - convert objdump address to a memory address.
564 * @map: memory map
565 * @ip: objdump address
566 *
567 * Closely related to map__rip_2objdump(), this function takes an address from
568 * objdump and converts it to a memory address.  Note this assumes that @map
569 * contains the address.  To be sure the result is valid, check it forwards
570 * e.g. map__rip_2objdump(map__map_ip(map, map__objdump_2mem(map, ip))) == ip
571 *
572 * Return: Memory address.
573 */
574u64 map__objdump_2mem(const struct map *map, u64 ip)
575{
576	const struct dso *dso = map__dso(map);
577
578	if (!dso__adjust_symbols(dso))
579		return map__unmap_ip(map, ip);
580
581	if (dso__rel(dso))
582		return map__unmap_ip(map, ip + map__pgoff(map));
583
584	if (dso__kernel(dso) == DSO_SPACE__USER)
585		return map__unmap_ip(map, ip - dso__text_offset(dso));
586
587	return ip + map__reloc(map);
588}
589
590/* convert objdump address to relative address.  (To be removed) */
591u64 map__objdump_2rip(const struct map *map, u64 ip)
592{
593	const struct dso *dso = map__dso(map);
594
595	if (!dso__adjust_symbols(dso))
596		return ip;
597
598	if (dso__rel(dso))
599		return ip + map__pgoff(map);
600
601	if (dso__kernel(dso) == DSO_SPACE__USER)
602		return ip - dso__text_offset(dso);
603
604	return map__map_ip(map, ip + map__reloc(map));
605}
606
607bool map__contains_symbol(const struct map *map, const struct symbol *sym)
608{
609	u64 ip = map__unmap_ip(map, sym->start);
610
611	return ip >= map__start(map) && ip < map__end(map);
612}
613
614struct kmap *__map__kmap(struct map *map)
615{
616	const struct dso *dso = map__dso(map);
617
618	if (!dso || !dso__kernel(dso))
619		return NULL;
620	return (struct kmap *)(&RC_CHK_ACCESS(map)[1]);
621}
622
623static const struct kmap *__map__const_kmap(const struct map *map)
624{
625	const struct dso *dso = map__dso(map);
626
627	if (!dso || !dso__kernel(dso))
628		return NULL;
629	return (struct kmap *)(&RC_CHK_ACCESS(map)[1]);
630}
631
632struct kmap *map__kmap(struct map *map)
633{
634	struct kmap *kmap = __map__kmap(map);
635
636	if (!kmap)
637		pr_err("Internal error: map__kmap with a non-kernel map\n");
638	return kmap;
639}
640
641struct maps *map__kmaps(struct map *map)
642{
643	struct kmap *kmap = map__kmap(map);
644
645	if (!kmap || !kmap->kmaps) {
646		pr_err("Internal error: map__kmaps with a non-kernel map\n");
647		return NULL;
648	}
649	return kmap->kmaps;
650}