xref: /kernel/linux/linux-5.10/tools/perf/util/symbol.c (revision 8c2ecf20)
1// SPDX-License-Identifier: GPL-2.0
2#include <dirent.h>
3#include <errno.h>
4#include <stdlib.h>
5#include <stdio.h>
6#include <string.h>
7#include <linux/capability.h>
8#include <linux/kernel.h>
9#include <linux/mman.h>
10#include <linux/string.h>
11#include <linux/time64.h>
12#include <sys/types.h>
13#include <sys/stat.h>
14#include <sys/param.h>
15#include <fcntl.h>
16#include <unistd.h>
17#include <inttypes.h>
18#include "annotate.h"
19#include "build-id.h"
20#include "cap.h"
21#include "dso.h"
22#include "util.h" // lsdir()
23#include "debug.h"
24#include "event.h"
25#include "machine.h"
26#include "map.h"
27#include "symbol.h"
28#include "map_symbol.h"
29#include "mem-events.h"
30#include "symsrc.h"
31#include "strlist.h"
32#include "intlist.h"
33#include "namespaces.h"
34#include "header.h"
35#include "path.h"
36#include <linux/ctype.h>
37#include <linux/zalloc.h>
38
39#include <elf.h>
40#include <limits.h>
41#include <symbol/kallsyms.h>
42#include <sys/utsname.h>
43
44static int dso__load_kernel_sym(struct dso *dso, struct map *map);
45static int dso__load_guest_kernel_sym(struct dso *dso, struct map *map);
46static bool symbol__is_idle(const char *name);
47
48int vmlinux_path__nr_entries;
49char **vmlinux_path;
50
51struct symbol_conf symbol_conf = {
52	.nanosecs		= false,
53	.use_modules		= true,
54	.try_vmlinux_path	= true,
55	.demangle		= true,
56	.demangle_kernel	= false,
57	.cumulate_callchain	= true,
58	.time_quantum		= 100 * NSEC_PER_MSEC, /* 100ms */
59	.show_hist_headers	= true,
60	.symfs			= "",
61	.event_group		= true,
62	.inline_name		= true,
63	.res_sample		= 0,
64};
65
66static enum dso_binary_type binary_type_symtab[] = {
67	DSO_BINARY_TYPE__KALLSYMS,
68	DSO_BINARY_TYPE__GUEST_KALLSYMS,
69	DSO_BINARY_TYPE__JAVA_JIT,
70	DSO_BINARY_TYPE__DEBUGLINK,
71	DSO_BINARY_TYPE__BUILD_ID_CACHE,
72	DSO_BINARY_TYPE__BUILD_ID_CACHE_DEBUGINFO,
73	DSO_BINARY_TYPE__FEDORA_DEBUGINFO,
74	DSO_BINARY_TYPE__UBUNTU_DEBUGINFO,
75	DSO_BINARY_TYPE__BUILDID_DEBUGINFO,
76	DSO_BINARY_TYPE__SYSTEM_PATH_DSO,
77	DSO_BINARY_TYPE__GUEST_KMODULE,
78	DSO_BINARY_TYPE__GUEST_KMODULE_COMP,
79	DSO_BINARY_TYPE__SYSTEM_PATH_KMODULE,
80	DSO_BINARY_TYPE__SYSTEM_PATH_KMODULE_COMP,
81	DSO_BINARY_TYPE__OPENEMBEDDED_DEBUGINFO,
82	DSO_BINARY_TYPE__MIXEDUP_UBUNTU_DEBUGINFO,
83	DSO_BINARY_TYPE__NOT_FOUND,
84};
85
86#define DSO_BINARY_TYPE__SYMTAB_CNT ARRAY_SIZE(binary_type_symtab)
87
88static bool symbol_type__filter(char symbol_type)
89{
90	symbol_type = toupper(symbol_type);
91	return symbol_type == 'T' || symbol_type == 'W' || symbol_type == 'D' || symbol_type == 'B';
92}
93
94static int prefix_underscores_count(const char *str)
95{
96	const char *tail = str;
97
98	while (*tail == '_')
99		tail++;
100
101	return tail - str;
102}
103
104const char * __weak arch__normalize_symbol_name(const char *name)
105{
106	return name;
107}
108
109int __weak arch__compare_symbol_names(const char *namea, const char *nameb)
110{
111	return strcmp(namea, nameb);
112}
113
114int __weak arch__compare_symbol_names_n(const char *namea, const char *nameb,
115					unsigned int n)
116{
117	return strncmp(namea, nameb, n);
118}
119
120int __weak arch__choose_best_symbol(struct symbol *syma,
121				    struct symbol *symb __maybe_unused)
122{
123	/* Avoid "SyS" kernel syscall aliases */
124	if (strlen(syma->name) >= 3 && !strncmp(syma->name, "SyS", 3))
125		return SYMBOL_B;
126	if (strlen(syma->name) >= 10 && !strncmp(syma->name, "compat_SyS", 10))
127		return SYMBOL_B;
128
129	return SYMBOL_A;
130}
131
132static int choose_best_symbol(struct symbol *syma, struct symbol *symb)
133{
134	s64 a;
135	s64 b;
136	size_t na, nb;
137
138	/* Prefer a symbol with non zero length */
139	a = syma->end - syma->start;
140	b = symb->end - symb->start;
141	if ((b == 0) && (a > 0))
142		return SYMBOL_A;
143	else if ((a == 0) && (b > 0))
144		return SYMBOL_B;
145
146	/* Prefer a non weak symbol over a weak one */
147	a = syma->binding == STB_WEAK;
148	b = symb->binding == STB_WEAK;
149	if (b && !a)
150		return SYMBOL_A;
151	if (a && !b)
152		return SYMBOL_B;
153
154	/* Prefer a global symbol over a non global one */
155	a = syma->binding == STB_GLOBAL;
156	b = symb->binding == STB_GLOBAL;
157	if (a && !b)
158		return SYMBOL_A;
159	if (b && !a)
160		return SYMBOL_B;
161
162	/* Prefer a symbol with less underscores */
163	a = prefix_underscores_count(syma->name);
164	b = prefix_underscores_count(symb->name);
165	if (b > a)
166		return SYMBOL_A;
167	else if (a > b)
168		return SYMBOL_B;
169
170	/* Choose the symbol with the longest name */
171	na = strlen(syma->name);
172	nb = strlen(symb->name);
173	if (na > nb)
174		return SYMBOL_A;
175	else if (na < nb)
176		return SYMBOL_B;
177
178	return arch__choose_best_symbol(syma, symb);
179}
180
181void symbols__fixup_duplicate(struct rb_root_cached *symbols)
182{
183	struct rb_node *nd;
184	struct symbol *curr, *next;
185
186	if (symbol_conf.allow_aliases)
187		return;
188
189	nd = rb_first_cached(symbols);
190
191	while (nd) {
192		curr = rb_entry(nd, struct symbol, rb_node);
193again:
194		nd = rb_next(&curr->rb_node);
195		next = rb_entry(nd, struct symbol, rb_node);
196
197		if (!nd)
198			break;
199
200		if (curr->start != next->start)
201			continue;
202
203		if (choose_best_symbol(curr, next) == SYMBOL_A) {
204			rb_erase_cached(&next->rb_node, symbols);
205			symbol__delete(next);
206			goto again;
207		} else {
208			nd = rb_next(&curr->rb_node);
209			rb_erase_cached(&curr->rb_node, symbols);
210			symbol__delete(curr);
211		}
212	}
213}
214
215/* Update zero-sized symbols using the address of the next symbol */
216void symbols__fixup_end(struct rb_root_cached *symbols, bool is_kallsyms)
217{
218	struct rb_node *nd, *prevnd = rb_first_cached(symbols);
219	struct symbol *curr, *prev;
220
221	if (prevnd == NULL)
222		return;
223
224	curr = rb_entry(prevnd, struct symbol, rb_node);
225
226	for (nd = rb_next(prevnd); nd; nd = rb_next(nd)) {
227		prev = curr;
228		curr = rb_entry(nd, struct symbol, rb_node);
229
230		/*
231		 * On some architecture kernel text segment start is located at
232		 * some low memory address, while modules are located at high
233		 * memory addresses (or vice versa).  The gap between end of
234		 * kernel text segment and beginning of first module's text
235		 * segment is very big.  Therefore do not fill this gap and do
236		 * not assign it to the kernel dso map (kallsyms).
237		 *
238		 * In kallsyms, it determines module symbols using '[' character
239		 * like in:
240		 *   ffffffffc1937000 T hdmi_driver_init  [snd_hda_codec_hdmi]
241		 */
242		if (prev->end == prev->start) {
243			/* Last kernel/module symbol mapped to end of page */
244			if (is_kallsyms && (!strchr(prev->name, '[') !=
245					    !strchr(curr->name, '[')))
246				prev->end = roundup(prev->end + 4096, 4096);
247			else
248				prev->end = curr->start;
249
250			pr_debug4("%s sym:%s end:%#" PRIx64 "\n",
251				  __func__, prev->name, prev->end);
252		}
253	}
254
255	/* Last entry */
256	if (curr->end == curr->start)
257		curr->end = roundup(curr->start, 4096) + 4096;
258}
259
260void maps__fixup_end(struct maps *maps)
261{
262	struct map *prev = NULL, *curr;
263
264	down_write(&maps->lock);
265
266	maps__for_each_entry(maps, curr) {
267		if (prev != NULL && !prev->end)
268			prev->end = curr->start;
269
270		prev = curr;
271	}
272
273	/*
274	 * We still haven't the actual symbols, so guess the
275	 * last map final address.
276	 */
277	if (curr && !curr->end)
278		curr->end = ~0ULL;
279
280	up_write(&maps->lock);
281}
282
283struct symbol *symbol__new(u64 start, u64 len, u8 binding, u8 type, const char *name)
284{
285	size_t namelen = strlen(name) + 1;
286	struct symbol *sym = calloc(1, (symbol_conf.priv_size +
287					sizeof(*sym) + namelen));
288	if (sym == NULL)
289		return NULL;
290
291	if (symbol_conf.priv_size) {
292		if (symbol_conf.init_annotation) {
293			struct annotation *notes = (void *)sym;
294			pthread_mutex_init(&notes->lock, NULL);
295		}
296		sym = ((void *)sym) + symbol_conf.priv_size;
297	}
298
299	sym->start   = start;
300	sym->end     = len ? start + len : start;
301	sym->type    = type;
302	sym->binding = binding;
303	sym->namelen = namelen - 1;
304
305	pr_debug4("%s: %s %#" PRIx64 "-%#" PRIx64 "\n",
306		  __func__, name, start, sym->end);
307	memcpy(sym->name, name, namelen);
308
309	return sym;
310}
311
312void symbol__delete(struct symbol *sym)
313{
314	free(((void *)sym) - symbol_conf.priv_size);
315}
316
317void symbols__delete(struct rb_root_cached *symbols)
318{
319	struct symbol *pos;
320	struct rb_node *next = rb_first_cached(symbols);
321
322	while (next) {
323		pos = rb_entry(next, struct symbol, rb_node);
324		next = rb_next(&pos->rb_node);
325		rb_erase_cached(&pos->rb_node, symbols);
326		symbol__delete(pos);
327	}
328}
329
330void __symbols__insert(struct rb_root_cached *symbols,
331		       struct symbol *sym, bool kernel)
332{
333	struct rb_node **p = &symbols->rb_root.rb_node;
334	struct rb_node *parent = NULL;
335	const u64 ip = sym->start;
336	struct symbol *s;
337	bool leftmost = true;
338
339	if (kernel) {
340		const char *name = sym->name;
341		/*
342		 * ppc64 uses function descriptors and appends a '.' to the
343		 * start of every instruction address. Remove it.
344		 */
345		if (name[0] == '.')
346			name++;
347		sym->idle = symbol__is_idle(name);
348	}
349
350	while (*p != NULL) {
351		parent = *p;
352		s = rb_entry(parent, struct symbol, rb_node);
353		if (ip < s->start)
354			p = &(*p)->rb_left;
355		else {
356			p = &(*p)->rb_right;
357			leftmost = false;
358		}
359	}
360	rb_link_node(&sym->rb_node, parent, p);
361	rb_insert_color_cached(&sym->rb_node, symbols, leftmost);
362}
363
364void symbols__insert(struct rb_root_cached *symbols, struct symbol *sym)
365{
366	__symbols__insert(symbols, sym, false);
367}
368
369static struct symbol *symbols__find(struct rb_root_cached *symbols, u64 ip)
370{
371	struct rb_node *n;
372
373	if (symbols == NULL)
374		return NULL;
375
376	n = symbols->rb_root.rb_node;
377
378	while (n) {
379		struct symbol *s = rb_entry(n, struct symbol, rb_node);
380
381		if (ip < s->start)
382			n = n->rb_left;
383		else if (ip > s->end || (ip == s->end && ip != s->start))
384			n = n->rb_right;
385		else
386			return s;
387	}
388
389	return NULL;
390}
391
392static struct symbol *symbols__first(struct rb_root_cached *symbols)
393{
394	struct rb_node *n = rb_first_cached(symbols);
395
396	if (n)
397		return rb_entry(n, struct symbol, rb_node);
398
399	return NULL;
400}
401
402static struct symbol *symbols__last(struct rb_root_cached *symbols)
403{
404	struct rb_node *n = rb_last(&symbols->rb_root);
405
406	if (n)
407		return rb_entry(n, struct symbol, rb_node);
408
409	return NULL;
410}
411
412static struct symbol *symbols__next(struct symbol *sym)
413{
414	struct rb_node *n = rb_next(&sym->rb_node);
415
416	if (n)
417		return rb_entry(n, struct symbol, rb_node);
418
419	return NULL;
420}
421
422static void symbols__insert_by_name(struct rb_root_cached *symbols, struct symbol *sym)
423{
424	struct rb_node **p = &symbols->rb_root.rb_node;
425	struct rb_node *parent = NULL;
426	struct symbol_name_rb_node *symn, *s;
427	bool leftmost = true;
428
429	symn = container_of(sym, struct symbol_name_rb_node, sym);
430
431	while (*p != NULL) {
432		parent = *p;
433		s = rb_entry(parent, struct symbol_name_rb_node, rb_node);
434		if (strcmp(sym->name, s->sym.name) < 0)
435			p = &(*p)->rb_left;
436		else {
437			p = &(*p)->rb_right;
438			leftmost = false;
439		}
440	}
441	rb_link_node(&symn->rb_node, parent, p);
442	rb_insert_color_cached(&symn->rb_node, symbols, leftmost);
443}
444
445static void symbols__sort_by_name(struct rb_root_cached *symbols,
446				  struct rb_root_cached *source)
447{
448	struct rb_node *nd;
449
450	for (nd = rb_first_cached(source); nd; nd = rb_next(nd)) {
451		struct symbol *pos = rb_entry(nd, struct symbol, rb_node);
452		symbols__insert_by_name(symbols, pos);
453	}
454}
455
456int symbol__match_symbol_name(const char *name, const char *str,
457			      enum symbol_tag_include includes)
458{
459	const char *versioning;
460
461	if (includes == SYMBOL_TAG_INCLUDE__DEFAULT_ONLY &&
462	    (versioning = strstr(name, "@@"))) {
463		int len = strlen(str);
464
465		if (len < versioning - name)
466			len = versioning - name;
467
468		return arch__compare_symbol_names_n(name, str, len);
469	} else
470		return arch__compare_symbol_names(name, str);
471}
472
473static struct symbol *symbols__find_by_name(struct rb_root_cached *symbols,
474					    const char *name,
475					    enum symbol_tag_include includes)
476{
477	struct rb_node *n;
478	struct symbol_name_rb_node *s = NULL;
479
480	if (symbols == NULL)
481		return NULL;
482
483	n = symbols->rb_root.rb_node;
484
485	while (n) {
486		int cmp;
487
488		s = rb_entry(n, struct symbol_name_rb_node, rb_node);
489		cmp = symbol__match_symbol_name(s->sym.name, name, includes);
490
491		if (cmp > 0)
492			n = n->rb_left;
493		else if (cmp < 0)
494			n = n->rb_right;
495		else
496			break;
497	}
498
499	if (n == NULL)
500		return NULL;
501
502	if (includes != SYMBOL_TAG_INCLUDE__DEFAULT_ONLY)
503		/* return first symbol that has same name (if any) */
504		for (n = rb_prev(n); n; n = rb_prev(n)) {
505			struct symbol_name_rb_node *tmp;
506
507			tmp = rb_entry(n, struct symbol_name_rb_node, rb_node);
508			if (arch__compare_symbol_names(tmp->sym.name, s->sym.name))
509				break;
510
511			s = tmp;
512		}
513
514	return &s->sym;
515}
516
517void dso__reset_find_symbol_cache(struct dso *dso)
518{
519	dso->last_find_result.addr   = 0;
520	dso->last_find_result.symbol = NULL;
521}
522
523void dso__insert_symbol(struct dso *dso, struct symbol *sym)
524{
525	__symbols__insert(&dso->symbols, sym, dso->kernel);
526
527	/* update the symbol cache if necessary */
528	if (dso->last_find_result.addr >= sym->start &&
529	    (dso->last_find_result.addr < sym->end ||
530	    sym->start == sym->end)) {
531		dso->last_find_result.symbol = sym;
532	}
533}
534
535void dso__delete_symbol(struct dso *dso, struct symbol *sym)
536{
537	rb_erase_cached(&sym->rb_node, &dso->symbols);
538	symbol__delete(sym);
539	dso__reset_find_symbol_cache(dso);
540}
541
542struct symbol *dso__find_symbol(struct dso *dso, u64 addr)
543{
544	if (dso->last_find_result.addr != addr || dso->last_find_result.symbol == NULL) {
545		dso->last_find_result.addr   = addr;
546		dso->last_find_result.symbol = symbols__find(&dso->symbols, addr);
547	}
548
549	return dso->last_find_result.symbol;
550}
551
552struct symbol *dso__first_symbol(struct dso *dso)
553{
554	return symbols__first(&dso->symbols);
555}
556
557struct symbol *dso__last_symbol(struct dso *dso)
558{
559	return symbols__last(&dso->symbols);
560}
561
562struct symbol *dso__next_symbol(struct symbol *sym)
563{
564	return symbols__next(sym);
565}
566
567struct symbol *symbol__next_by_name(struct symbol *sym)
568{
569	struct symbol_name_rb_node *s = container_of(sym, struct symbol_name_rb_node, sym);
570	struct rb_node *n = rb_next(&s->rb_node);
571
572	return n ? &rb_entry(n, struct symbol_name_rb_node, rb_node)->sym : NULL;
573}
574
575 /*
576  * Returns first symbol that matched with @name.
577  */
578struct symbol *dso__find_symbol_by_name(struct dso *dso, const char *name)
579{
580	struct symbol *s = symbols__find_by_name(&dso->symbol_names, name,
581						 SYMBOL_TAG_INCLUDE__NONE);
582	if (!s)
583		s = symbols__find_by_name(&dso->symbol_names, name,
584					  SYMBOL_TAG_INCLUDE__DEFAULT_ONLY);
585	return s;
586}
587
588void dso__sort_by_name(struct dso *dso)
589{
590	dso__set_sorted_by_name(dso);
591	return symbols__sort_by_name(&dso->symbol_names, &dso->symbols);
592}
593
594/*
595 * While we find nice hex chars, build a long_val.
596 * Return number of chars processed.
597 */
598static int hex2u64(const char *ptr, u64 *long_val)
599{
600	char *p;
601
602	*long_val = strtoull(ptr, &p, 16);
603
604	return p - ptr;
605}
606
607
608int modules__parse(const char *filename, void *arg,
609		   int (*process_module)(void *arg, const char *name,
610					 u64 start, u64 size))
611{
612	char *line = NULL;
613	size_t n;
614	FILE *file;
615	int err = 0;
616
617	file = fopen(filename, "r");
618	if (file == NULL)
619		return -1;
620
621	while (1) {
622		char name[PATH_MAX];
623		u64 start, size;
624		char *sep, *endptr;
625		ssize_t line_len;
626
627		line_len = getline(&line, &n, file);
628		if (line_len < 0) {
629			if (feof(file))
630				break;
631			err = -1;
632			goto out;
633		}
634
635		if (!line) {
636			err = -1;
637			goto out;
638		}
639
640		line[--line_len] = '\0'; /* \n */
641
642		sep = strrchr(line, 'x');
643		if (sep == NULL)
644			continue;
645
646		hex2u64(sep + 1, &start);
647
648		sep = strchr(line, ' ');
649		if (sep == NULL)
650			continue;
651
652		*sep = '\0';
653
654		scnprintf(name, sizeof(name), "[%s]", line);
655
656		size = strtoul(sep + 1, &endptr, 0);
657		if (*endptr != ' ' && *endptr != '\t')
658			continue;
659
660		err = process_module(arg, name, start, size);
661		if (err)
662			break;
663	}
664out:
665	free(line);
666	fclose(file);
667	return err;
668}
669
670/*
671 * These are symbols in the kernel image, so make sure that
672 * sym is from a kernel DSO.
673 */
674static bool symbol__is_idle(const char *name)
675{
676	const char * const idle_symbols[] = {
677		"acpi_idle_do_entry",
678		"acpi_processor_ffh_cstate_enter",
679		"arch_cpu_idle",
680		"cpu_idle",
681		"cpu_startup_entry",
682		"idle_cpu",
683		"intel_idle",
684		"default_idle",
685		"native_safe_halt",
686		"enter_idle",
687		"exit_idle",
688		"mwait_idle",
689		"mwait_idle_with_hints",
690		"mwait_idle_with_hints.constprop.0",
691		"poll_idle",
692		"ppc64_runlatch_off",
693		"pseries_dedicated_idle_sleep",
694		"psw_idle",
695		"psw_idle_exit",
696		NULL
697	};
698	int i;
699	static struct strlist *idle_symbols_list;
700
701	if (idle_symbols_list)
702		return strlist__has_entry(idle_symbols_list, name);
703
704	idle_symbols_list = strlist__new(NULL, NULL);
705
706	for (i = 0; idle_symbols[i]; i++)
707		strlist__add(idle_symbols_list, idle_symbols[i]);
708
709	return strlist__has_entry(idle_symbols_list, name);
710}
711
712static int map__process_kallsym_symbol(void *arg, const char *name,
713				       char type, u64 start)
714{
715	struct symbol *sym;
716	struct dso *dso = arg;
717	struct rb_root_cached *root = &dso->symbols;
718
719	if (!symbol_type__filter(type))
720		return 0;
721
722	/*
723	 * module symbols are not sorted so we add all
724	 * symbols, setting length to 0, and rely on
725	 * symbols__fixup_end() to fix it up.
726	 */
727	sym = symbol__new(start, 0, kallsyms2elf_binding(type), kallsyms2elf_type(type), name);
728	if (sym == NULL)
729		return -ENOMEM;
730	/*
731	 * We will pass the symbols to the filter later, in
732	 * map__split_kallsyms, when we have split the maps per module
733	 */
734	__symbols__insert(root, sym, !strchr(name, '['));
735
736	return 0;
737}
738
739/*
740 * Loads the function entries in /proc/kallsyms into kernel_map->dso,
741 * so that we can in the next step set the symbol ->end address and then
742 * call kernel_maps__split_kallsyms.
743 */
744static int dso__load_all_kallsyms(struct dso *dso, const char *filename)
745{
746	return kallsyms__parse(filename, dso, map__process_kallsym_symbol);
747}
748
749static int maps__split_kallsyms_for_kcore(struct maps *kmaps, struct dso *dso)
750{
751	struct map *curr_map;
752	struct symbol *pos;
753	int count = 0;
754	struct rb_root_cached old_root = dso->symbols;
755	struct rb_root_cached *root = &dso->symbols;
756	struct rb_node *next = rb_first_cached(root);
757
758	if (!kmaps)
759		return -1;
760
761	*root = RB_ROOT_CACHED;
762
763	while (next) {
764		char *module;
765
766		pos = rb_entry(next, struct symbol, rb_node);
767		next = rb_next(&pos->rb_node);
768
769		rb_erase_cached(&pos->rb_node, &old_root);
770		RB_CLEAR_NODE(&pos->rb_node);
771		module = strchr(pos->name, '\t');
772		if (module)
773			*module = '\0';
774
775		curr_map = maps__find(kmaps, pos->start);
776
777		if (!curr_map) {
778			symbol__delete(pos);
779			continue;
780		}
781
782		pos->start -= curr_map->start - curr_map->pgoff;
783		if (pos->end > curr_map->end)
784			pos->end = curr_map->end;
785		if (pos->end)
786			pos->end -= curr_map->start - curr_map->pgoff;
787		symbols__insert(&curr_map->dso->symbols, pos);
788		++count;
789	}
790
791	/* Symbols have been adjusted */
792	dso->adjust_symbols = 1;
793
794	return count;
795}
796
797/*
798 * Split the symbols into maps, making sure there are no overlaps, i.e. the
799 * kernel range is broken in several maps, named [kernel].N, as we don't have
800 * the original ELF section names vmlinux have.
801 */
802static int maps__split_kallsyms(struct maps *kmaps, struct dso *dso, u64 delta,
803				struct map *initial_map)
804{
805	struct machine *machine;
806	struct map *curr_map = initial_map;
807	struct symbol *pos;
808	int count = 0, moved = 0;
809	struct rb_root_cached *root = &dso->symbols;
810	struct rb_node *next = rb_first_cached(root);
811	int kernel_range = 0;
812	bool x86_64;
813
814	if (!kmaps)
815		return -1;
816
817	machine = kmaps->machine;
818
819	x86_64 = machine__is(machine, "x86_64");
820
821	while (next) {
822		char *module;
823
824		pos = rb_entry(next, struct symbol, rb_node);
825		next = rb_next(&pos->rb_node);
826
827		module = strchr(pos->name, '\t');
828		if (module) {
829			if (!symbol_conf.use_modules)
830				goto discard_symbol;
831
832			*module++ = '\0';
833
834			if (strcmp(curr_map->dso->short_name, module)) {
835				if (curr_map != initial_map &&
836				    dso->kernel == DSO_SPACE__KERNEL_GUEST &&
837				    machine__is_default_guest(machine)) {
838					/*
839					 * We assume all symbols of a module are
840					 * continuous in * kallsyms, so curr_map
841					 * points to a module and all its
842					 * symbols are in its kmap. Mark it as
843					 * loaded.
844					 */
845					dso__set_loaded(curr_map->dso);
846				}
847
848				curr_map = maps__find_by_name(kmaps, module);
849				if (curr_map == NULL) {
850					pr_debug("%s/proc/{kallsyms,modules} "
851					         "inconsistency while looking "
852						 "for \"%s\" module!\n",
853						 machine->root_dir, module);
854					curr_map = initial_map;
855					goto discard_symbol;
856				}
857
858				if (curr_map->dso->loaded &&
859				    !machine__is_default_guest(machine))
860					goto discard_symbol;
861			}
862			/*
863			 * So that we look just like we get from .ko files,
864			 * i.e. not prelinked, relative to initial_map->start.
865			 */
866			pos->start = curr_map->map_ip(curr_map, pos->start);
867			pos->end   = curr_map->map_ip(curr_map, pos->end);
868		} else if (x86_64 && is_entry_trampoline(pos->name)) {
869			/*
870			 * These symbols are not needed anymore since the
871			 * trampoline maps refer to the text section and it's
872			 * symbols instead. Avoid having to deal with
873			 * relocations, and the assumption that the first symbol
874			 * is the start of kernel text, by simply removing the
875			 * symbols at this point.
876			 */
877			goto discard_symbol;
878		} else if (curr_map != initial_map) {
879			char dso_name[PATH_MAX];
880			struct dso *ndso;
881
882			if (delta) {
883				/* Kernel was relocated at boot time */
884				pos->start -= delta;
885				pos->end -= delta;
886			}
887
888			if (count == 0) {
889				curr_map = initial_map;
890				goto add_symbol;
891			}
892
893			if (dso->kernel == DSO_SPACE__KERNEL_GUEST)
894				snprintf(dso_name, sizeof(dso_name),
895					"[guest.kernel].%d",
896					kernel_range++);
897			else
898				snprintf(dso_name, sizeof(dso_name),
899					"[kernel].%d",
900					kernel_range++);
901
902			ndso = dso__new(dso_name);
903			if (ndso == NULL)
904				return -1;
905
906			ndso->kernel = dso->kernel;
907
908			curr_map = map__new2(pos->start, ndso);
909			if (curr_map == NULL) {
910				dso__put(ndso);
911				return -1;
912			}
913
914			curr_map->map_ip = curr_map->unmap_ip = identity__map_ip;
915			maps__insert(kmaps, curr_map);
916			++kernel_range;
917		} else if (delta) {
918			/* Kernel was relocated at boot time */
919			pos->start -= delta;
920			pos->end -= delta;
921		}
922add_symbol:
923		if (curr_map != initial_map) {
924			rb_erase_cached(&pos->rb_node, root);
925			symbols__insert(&curr_map->dso->symbols, pos);
926			++moved;
927		} else
928			++count;
929
930		continue;
931discard_symbol:
932		rb_erase_cached(&pos->rb_node, root);
933		symbol__delete(pos);
934	}
935
936	if (curr_map != initial_map &&
937	    dso->kernel == DSO_SPACE__KERNEL_GUEST &&
938	    machine__is_default_guest(kmaps->machine)) {
939		dso__set_loaded(curr_map->dso);
940	}
941
942	return count + moved;
943}
944
945bool symbol__restricted_filename(const char *filename,
946				 const char *restricted_filename)
947{
948	bool restricted = false;
949
950	if (symbol_conf.kptr_restrict) {
951		char *r = realpath(filename, NULL);
952
953		if (r != NULL) {
954			restricted = strcmp(r, restricted_filename) == 0;
955			free(r);
956			return restricted;
957		}
958	}
959
960	return restricted;
961}
962
963struct module_info {
964	struct rb_node rb_node;
965	char *name;
966	u64 start;
967};
968
969static void add_module(struct module_info *mi, struct rb_root *modules)
970{
971	struct rb_node **p = &modules->rb_node;
972	struct rb_node *parent = NULL;
973	struct module_info *m;
974
975	while (*p != NULL) {
976		parent = *p;
977		m = rb_entry(parent, struct module_info, rb_node);
978		if (strcmp(mi->name, m->name) < 0)
979			p = &(*p)->rb_left;
980		else
981			p = &(*p)->rb_right;
982	}
983	rb_link_node(&mi->rb_node, parent, p);
984	rb_insert_color(&mi->rb_node, modules);
985}
986
987static void delete_modules(struct rb_root *modules)
988{
989	struct module_info *mi;
990	struct rb_node *next = rb_first(modules);
991
992	while (next) {
993		mi = rb_entry(next, struct module_info, rb_node);
994		next = rb_next(&mi->rb_node);
995		rb_erase(&mi->rb_node, modules);
996		zfree(&mi->name);
997		free(mi);
998	}
999}
1000
1001static struct module_info *find_module(const char *name,
1002				       struct rb_root *modules)
1003{
1004	struct rb_node *n = modules->rb_node;
1005
1006	while (n) {
1007		struct module_info *m;
1008		int cmp;
1009
1010		m = rb_entry(n, struct module_info, rb_node);
1011		cmp = strcmp(name, m->name);
1012		if (cmp < 0)
1013			n = n->rb_left;
1014		else if (cmp > 0)
1015			n = n->rb_right;
1016		else
1017			return m;
1018	}
1019
1020	return NULL;
1021}
1022
1023static int __read_proc_modules(void *arg, const char *name, u64 start,
1024			       u64 size __maybe_unused)
1025{
1026	struct rb_root *modules = arg;
1027	struct module_info *mi;
1028
1029	mi = zalloc(sizeof(struct module_info));
1030	if (!mi)
1031		return -ENOMEM;
1032
1033	mi->name = strdup(name);
1034	mi->start = start;
1035
1036	if (!mi->name) {
1037		free(mi);
1038		return -ENOMEM;
1039	}
1040
1041	add_module(mi, modules);
1042
1043	return 0;
1044}
1045
1046static int read_proc_modules(const char *filename, struct rb_root *modules)
1047{
1048	if (symbol__restricted_filename(filename, "/proc/modules"))
1049		return -1;
1050
1051	if (modules__parse(filename, modules, __read_proc_modules)) {
1052		delete_modules(modules);
1053		return -1;
1054	}
1055
1056	return 0;
1057}
1058
1059int compare_proc_modules(const char *from, const char *to)
1060{
1061	struct rb_root from_modules = RB_ROOT;
1062	struct rb_root to_modules = RB_ROOT;
1063	struct rb_node *from_node, *to_node;
1064	struct module_info *from_m, *to_m;
1065	int ret = -1;
1066
1067	if (read_proc_modules(from, &from_modules))
1068		return -1;
1069
1070	if (read_proc_modules(to, &to_modules))
1071		goto out_delete_from;
1072
1073	from_node = rb_first(&from_modules);
1074	to_node = rb_first(&to_modules);
1075	while (from_node) {
1076		if (!to_node)
1077			break;
1078
1079		from_m = rb_entry(from_node, struct module_info, rb_node);
1080		to_m = rb_entry(to_node, struct module_info, rb_node);
1081
1082		if (from_m->start != to_m->start ||
1083		    strcmp(from_m->name, to_m->name))
1084			break;
1085
1086		from_node = rb_next(from_node);
1087		to_node = rb_next(to_node);
1088	}
1089
1090	if (!from_node && !to_node)
1091		ret = 0;
1092
1093	delete_modules(&to_modules);
1094out_delete_from:
1095	delete_modules(&from_modules);
1096
1097	return ret;
1098}
1099
1100static int do_validate_kcore_modules(const char *filename, struct maps *kmaps)
1101{
1102	struct rb_root modules = RB_ROOT;
1103	struct map *old_map;
1104	int err;
1105
1106	err = read_proc_modules(filename, &modules);
1107	if (err)
1108		return err;
1109
1110	maps__for_each_entry(kmaps, old_map) {
1111		struct module_info *mi;
1112
1113		if (!__map__is_kmodule(old_map)) {
1114			continue;
1115		}
1116
1117		/* Module must be in memory at the same address */
1118		mi = find_module(old_map->dso->short_name, &modules);
1119		if (!mi || mi->start != old_map->start) {
1120			err = -EINVAL;
1121			goto out;
1122		}
1123	}
1124out:
1125	delete_modules(&modules);
1126	return err;
1127}
1128
1129/*
1130 * If kallsyms is referenced by name then we look for filename in the same
1131 * directory.
1132 */
1133static bool filename_from_kallsyms_filename(char *filename,
1134					    const char *base_name,
1135					    const char *kallsyms_filename)
1136{
1137	char *name;
1138
1139	strcpy(filename, kallsyms_filename);
1140	name = strrchr(filename, '/');
1141	if (!name)
1142		return false;
1143
1144	name += 1;
1145
1146	if (!strcmp(name, "kallsyms")) {
1147		strcpy(name, base_name);
1148		return true;
1149	}
1150
1151	return false;
1152}
1153
1154static int validate_kcore_modules(const char *kallsyms_filename,
1155				  struct map *map)
1156{
1157	struct maps *kmaps = map__kmaps(map);
1158	char modules_filename[PATH_MAX];
1159
1160	if (!kmaps)
1161		return -EINVAL;
1162
1163	if (!filename_from_kallsyms_filename(modules_filename, "modules",
1164					     kallsyms_filename))
1165		return -EINVAL;
1166
1167	if (do_validate_kcore_modules(modules_filename, kmaps))
1168		return -EINVAL;
1169
1170	return 0;
1171}
1172
1173static int validate_kcore_addresses(const char *kallsyms_filename,
1174				    struct map *map)
1175{
1176	struct kmap *kmap = map__kmap(map);
1177
1178	if (!kmap)
1179		return -EINVAL;
1180
1181	if (kmap->ref_reloc_sym && kmap->ref_reloc_sym->name) {
1182		u64 start;
1183
1184		if (kallsyms__get_function_start(kallsyms_filename,
1185						 kmap->ref_reloc_sym->name, &start))
1186			return -ENOENT;
1187		if (start != kmap->ref_reloc_sym->addr)
1188			return -EINVAL;
1189	}
1190
1191	return validate_kcore_modules(kallsyms_filename, map);
1192}
1193
1194struct kcore_mapfn_data {
1195	struct dso *dso;
1196	struct list_head maps;
1197};
1198
1199static int kcore_mapfn(u64 start, u64 len, u64 pgoff, void *data)
1200{
1201	struct kcore_mapfn_data *md = data;
1202	struct map *map;
1203
1204	map = map__new2(start, md->dso);
1205	if (map == NULL)
1206		return -ENOMEM;
1207
1208	map->end = map->start + len;
1209	map->pgoff = pgoff;
1210
1211	list_add(&map->node, &md->maps);
1212
1213	return 0;
1214}
1215
1216/*
1217 * Merges map into maps by splitting the new map within the existing map
1218 * regions.
1219 */
1220int maps__merge_in(struct maps *kmaps, struct map *new_map)
1221{
1222	struct map *old_map;
1223	LIST_HEAD(merged);
1224
1225	maps__for_each_entry(kmaps, old_map) {
1226		/* no overload with this one */
1227		if (new_map->end < old_map->start ||
1228		    new_map->start >= old_map->end)
1229			continue;
1230
1231		if (new_map->start < old_map->start) {
1232			/*
1233			 * |new......
1234			 *       |old....
1235			 */
1236			if (new_map->end < old_map->end) {
1237				/*
1238				 * |new......|     -> |new..|
1239				 *       |old....| ->       |old....|
1240				 */
1241				new_map->end = old_map->start;
1242			} else {
1243				/*
1244				 * |new.............| -> |new..|       |new..|
1245				 *       |old....|    ->       |old....|
1246				 */
1247				struct map *m = map__clone(new_map);
1248
1249				if (!m)
1250					return -ENOMEM;
1251
1252				m->end = old_map->start;
1253				list_add_tail(&m->node, &merged);
1254				new_map->pgoff += old_map->end - new_map->start;
1255				new_map->start = old_map->end;
1256			}
1257		} else {
1258			/*
1259			 *      |new......
1260			 * |old....
1261			 */
1262			if (new_map->end < old_map->end) {
1263				/*
1264				 *      |new..|   -> x
1265				 * |old.........| -> |old.........|
1266				 */
1267				map__put(new_map);
1268				new_map = NULL;
1269				break;
1270			} else {
1271				/*
1272				 *      |new......| ->         |new...|
1273				 * |old....|        -> |old....|
1274				 */
1275				new_map->pgoff += old_map->end - new_map->start;
1276				new_map->start = old_map->end;
1277			}
1278		}
1279	}
1280
1281	while (!list_empty(&merged)) {
1282		old_map = list_entry(merged.next, struct map, node);
1283		list_del_init(&old_map->node);
1284		maps__insert(kmaps, old_map);
1285		map__put(old_map);
1286	}
1287
1288	if (new_map) {
1289		maps__insert(kmaps, new_map);
1290		map__put(new_map);
1291	}
1292	return 0;
1293}
1294
1295static int dso__load_kcore(struct dso *dso, struct map *map,
1296			   const char *kallsyms_filename)
1297{
1298	struct maps *kmaps = map__kmaps(map);
1299	struct kcore_mapfn_data md;
1300	struct map *old_map, *new_map, *replacement_map = NULL, *next;
1301	struct machine *machine;
1302	bool is_64_bit;
1303	int err, fd;
1304	char kcore_filename[PATH_MAX];
1305	u64 stext;
1306
1307	if (!kmaps)
1308		return -EINVAL;
1309
1310	machine = kmaps->machine;
1311
1312	/* This function requires that the map is the kernel map */
1313	if (!__map__is_kernel(map))
1314		return -EINVAL;
1315
1316	if (!filename_from_kallsyms_filename(kcore_filename, "kcore",
1317					     kallsyms_filename))
1318		return -EINVAL;
1319
1320	/* Modules and kernel must be present at their original addresses */
1321	if (validate_kcore_addresses(kallsyms_filename, map))
1322		return -EINVAL;
1323
1324	md.dso = dso;
1325	INIT_LIST_HEAD(&md.maps);
1326
1327	fd = open(kcore_filename, O_RDONLY);
1328	if (fd < 0) {
1329		pr_debug("Failed to open %s. Note /proc/kcore requires CAP_SYS_RAWIO capability to access.\n",
1330			 kcore_filename);
1331		return -EINVAL;
1332	}
1333
1334	/* Read new maps into temporary lists */
1335	err = file__read_maps(fd, map->prot & PROT_EXEC, kcore_mapfn, &md,
1336			      &is_64_bit);
1337	if (err)
1338		goto out_err;
1339	dso->is_64_bit = is_64_bit;
1340
1341	if (list_empty(&md.maps)) {
1342		err = -EINVAL;
1343		goto out_err;
1344	}
1345
1346	/* Remove old maps */
1347	maps__for_each_entry_safe(kmaps, old_map, next) {
1348		/*
1349		 * We need to preserve eBPF maps even if they are
1350		 * covered by kcore, because we need to access
1351		 * eBPF dso for source data.
1352		 */
1353		if (old_map != map && !__map__is_bpf_prog(old_map))
1354			maps__remove(kmaps, old_map);
1355	}
1356	machine->trampolines_mapped = false;
1357
1358	/* Find the kernel map using the '_stext' symbol */
1359	if (!kallsyms__get_function_start(kallsyms_filename, "_stext", &stext)) {
1360		list_for_each_entry(new_map, &md.maps, node) {
1361			if (stext >= new_map->start && stext < new_map->end) {
1362				replacement_map = new_map;
1363				break;
1364			}
1365		}
1366	}
1367
1368	if (!replacement_map)
1369		replacement_map = list_entry(md.maps.next, struct map, node);
1370
1371	/* Add new maps */
1372	while (!list_empty(&md.maps)) {
1373		new_map = list_entry(md.maps.next, struct map, node);
1374		list_del_init(&new_map->node);
1375		if (new_map == replacement_map) {
1376			map->start	= new_map->start;
1377			map->end	= new_map->end;
1378			map->pgoff	= new_map->pgoff;
1379			map->map_ip	= new_map->map_ip;
1380			map->unmap_ip	= new_map->unmap_ip;
1381			/* Ensure maps are correctly ordered */
1382			map__get(map);
1383			maps__remove(kmaps, map);
1384			maps__insert(kmaps, map);
1385			map__put(map);
1386			map__put(new_map);
1387		} else {
1388			/*
1389			 * Merge kcore map into existing maps,
1390			 * and ensure that current maps (eBPF)
1391			 * stay intact.
1392			 */
1393			if (maps__merge_in(kmaps, new_map))
1394				goto out_err;
1395		}
1396	}
1397
1398	if (machine__is(machine, "x86_64")) {
1399		u64 addr;
1400
1401		/*
1402		 * If one of the corresponding symbols is there, assume the
1403		 * entry trampoline maps are too.
1404		 */
1405		if (!kallsyms__get_function_start(kallsyms_filename,
1406						  ENTRY_TRAMPOLINE_NAME,
1407						  &addr))
1408			machine->trampolines_mapped = true;
1409	}
1410
1411	/*
1412	 * Set the data type and long name so that kcore can be read via
1413	 * dso__data_read_addr().
1414	 */
1415	if (dso->kernel == DSO_SPACE__KERNEL_GUEST)
1416		dso->binary_type = DSO_BINARY_TYPE__GUEST_KCORE;
1417	else
1418		dso->binary_type = DSO_BINARY_TYPE__KCORE;
1419	dso__set_long_name(dso, strdup(kcore_filename), true);
1420
1421	close(fd);
1422
1423	if (map->prot & PROT_EXEC)
1424		pr_debug("Using %s for kernel object code\n", kcore_filename);
1425	else
1426		pr_debug("Using %s for kernel data\n", kcore_filename);
1427
1428	return 0;
1429
1430out_err:
1431	while (!list_empty(&md.maps)) {
1432		map = list_entry(md.maps.next, struct map, node);
1433		list_del_init(&map->node);
1434		map__put(map);
1435	}
1436	close(fd);
1437	return -EINVAL;
1438}
1439
1440/*
1441 * If the kernel is relocated at boot time, kallsyms won't match.  Compute the
1442 * delta based on the relocation reference symbol.
1443 */
1444static int kallsyms__delta(struct kmap *kmap, const char *filename, u64 *delta)
1445{
1446	u64 addr;
1447
1448	if (!kmap->ref_reloc_sym || !kmap->ref_reloc_sym->name)
1449		return 0;
1450
1451	if (kallsyms__get_function_start(filename, kmap->ref_reloc_sym->name, &addr))
1452		return -1;
1453
1454	*delta = addr - kmap->ref_reloc_sym->addr;
1455	return 0;
1456}
1457
1458int __dso__load_kallsyms(struct dso *dso, const char *filename,
1459			 struct map *map, bool no_kcore)
1460{
1461	struct kmap *kmap = map__kmap(map);
1462	u64 delta = 0;
1463
1464	if (symbol__restricted_filename(filename, "/proc/kallsyms"))
1465		return -1;
1466
1467	if (!kmap || !kmap->kmaps)
1468		return -1;
1469
1470	if (dso__load_all_kallsyms(dso, filename) < 0)
1471		return -1;
1472
1473	if (kallsyms__delta(kmap, filename, &delta))
1474		return -1;
1475
1476	symbols__fixup_end(&dso->symbols, true);
1477	symbols__fixup_duplicate(&dso->symbols);
1478
1479	if (dso->kernel == DSO_SPACE__KERNEL_GUEST)
1480		dso->symtab_type = DSO_BINARY_TYPE__GUEST_KALLSYMS;
1481	else
1482		dso->symtab_type = DSO_BINARY_TYPE__KALLSYMS;
1483
1484	if (!no_kcore && !dso__load_kcore(dso, map, filename))
1485		return maps__split_kallsyms_for_kcore(kmap->kmaps, dso);
1486	else
1487		return maps__split_kallsyms(kmap->kmaps, dso, delta, map);
1488}
1489
1490int dso__load_kallsyms(struct dso *dso, const char *filename,
1491		       struct map *map)
1492{
1493	return __dso__load_kallsyms(dso, filename, map, false);
1494}
1495
1496static int dso__load_perf_map(const char *map_path, struct dso *dso)
1497{
1498	char *line = NULL;
1499	size_t n;
1500	FILE *file;
1501	int nr_syms = 0;
1502
1503	file = fopen(map_path, "r");
1504	if (file == NULL)
1505		goto out_failure;
1506
1507	while (!feof(file)) {
1508		u64 start, size;
1509		struct symbol *sym;
1510		int line_len, len;
1511
1512		line_len = getline(&line, &n, file);
1513		if (line_len < 0)
1514			break;
1515
1516		if (!line)
1517			goto out_failure;
1518
1519		line[--line_len] = '\0'; /* \n */
1520
1521		len = hex2u64(line, &start);
1522
1523		len++;
1524		if (len + 2 >= line_len)
1525			continue;
1526
1527		len += hex2u64(line + len, &size);
1528
1529		len++;
1530		if (len + 2 >= line_len)
1531			continue;
1532
1533		sym = symbol__new(start, size, STB_GLOBAL, STT_FUNC, line + len);
1534
1535		if (sym == NULL)
1536			goto out_delete_line;
1537
1538		symbols__insert(&dso->symbols, sym);
1539		nr_syms++;
1540	}
1541
1542	free(line);
1543	fclose(file);
1544
1545	return nr_syms;
1546
1547out_delete_line:
1548	free(line);
1549out_failure:
1550	return -1;
1551}
1552
1553#ifdef HAVE_LIBBFD_SUPPORT
1554#define PACKAGE 'perf'
1555#include <bfd.h>
1556
1557static int bfd_symbols__cmpvalue(const void *a, const void *b)
1558{
1559	const asymbol *as = *(const asymbol **)a, *bs = *(const asymbol **)b;
1560
1561	if (bfd_asymbol_value(as) != bfd_asymbol_value(bs))
1562		return bfd_asymbol_value(as) - bfd_asymbol_value(bs);
1563
1564	return bfd_asymbol_name(as)[0] - bfd_asymbol_name(bs)[0];
1565}
1566
1567static int bfd2elf_binding(asymbol *symbol)
1568{
1569	if (symbol->flags & BSF_WEAK)
1570		return STB_WEAK;
1571	if (symbol->flags & BSF_GLOBAL)
1572		return STB_GLOBAL;
1573	if (symbol->flags & BSF_LOCAL)
1574		return STB_LOCAL;
1575	return -1;
1576}
1577
1578int dso__load_bfd_symbols(struct dso *dso, const char *debugfile)
1579{
1580	int err = -1;
1581	long symbols_size, symbols_count, i;
1582	asection *section;
1583	asymbol **symbols, *sym;
1584	struct symbol *symbol;
1585	bfd *abfd;
1586	u64 start, len;
1587
1588	abfd = bfd_openr(dso->long_name, NULL);
1589	if (!abfd)
1590		return -1;
1591
1592	if (!bfd_check_format(abfd, bfd_object)) {
1593		pr_debug2("%s: cannot read %s bfd file.\n", __func__,
1594			  dso->long_name);
1595		goto out_close;
1596	}
1597
1598	if (bfd_get_flavour(abfd) == bfd_target_elf_flavour)
1599		goto out_close;
1600
1601	section = bfd_get_section_by_name(abfd, ".text");
1602	if (section)
1603		dso->text_offset = section->vma - section->filepos;
1604
1605	bfd_close(abfd);
1606
1607	abfd = bfd_openr(debugfile, NULL);
1608	if (!abfd)
1609		return -1;
1610
1611	if (!bfd_check_format(abfd, bfd_object)) {
1612		pr_debug2("%s: cannot read %s bfd file.\n", __func__,
1613			  debugfile);
1614		goto out_close;
1615	}
1616
1617	if (bfd_get_flavour(abfd) == bfd_target_elf_flavour)
1618		goto out_close;
1619
1620	symbols_size = bfd_get_symtab_upper_bound(abfd);
1621	if (symbols_size == 0) {
1622		bfd_close(abfd);
1623		return 0;
1624	}
1625
1626	if (symbols_size < 0)
1627		goto out_close;
1628
1629	symbols = malloc(symbols_size);
1630	if (!symbols)
1631		goto out_close;
1632
1633	symbols_count = bfd_canonicalize_symtab(abfd, symbols);
1634	if (symbols_count < 0)
1635		goto out_free;
1636
1637	qsort(symbols, symbols_count, sizeof(asymbol *), bfd_symbols__cmpvalue);
1638
1639#ifdef bfd_get_section
1640#define bfd_asymbol_section bfd_get_section
1641#endif
1642	for (i = 0; i < symbols_count; ++i) {
1643		sym = symbols[i];
1644		section = bfd_asymbol_section(sym);
1645		if (bfd2elf_binding(sym) < 0)
1646			continue;
1647
1648		while (i + 1 < symbols_count &&
1649		       bfd_asymbol_section(symbols[i + 1]) == section &&
1650		       bfd2elf_binding(symbols[i + 1]) < 0)
1651			i++;
1652
1653		if (i + 1 < symbols_count &&
1654		    bfd_asymbol_section(symbols[i + 1]) == section)
1655			len = symbols[i + 1]->value - sym->value;
1656		else
1657			len = section->size - sym->value;
1658
1659		start = bfd_asymbol_value(sym) - dso->text_offset;
1660		symbol = symbol__new(start, len, bfd2elf_binding(sym), STT_FUNC,
1661				     bfd_asymbol_name(sym));
1662		if (!symbol)
1663			goto out_free;
1664
1665		symbols__insert(&dso->symbols, symbol);
1666	}
1667#ifdef bfd_get_section
1668#undef bfd_asymbol_section
1669#endif
1670
1671	symbols__fixup_end(&dso->symbols, false);
1672	symbols__fixup_duplicate(&dso->symbols);
1673	dso->adjust_symbols = 1;
1674
1675	err = 0;
1676out_free:
1677	free(symbols);
1678out_close:
1679	bfd_close(abfd);
1680	return err;
1681}
1682#endif
1683
1684static bool dso__is_compatible_symtab_type(struct dso *dso, bool kmod,
1685					   enum dso_binary_type type)
1686{
1687	switch (type) {
1688	case DSO_BINARY_TYPE__JAVA_JIT:
1689	case DSO_BINARY_TYPE__DEBUGLINK:
1690	case DSO_BINARY_TYPE__SYSTEM_PATH_DSO:
1691	case DSO_BINARY_TYPE__FEDORA_DEBUGINFO:
1692	case DSO_BINARY_TYPE__UBUNTU_DEBUGINFO:
1693	case DSO_BINARY_TYPE__MIXEDUP_UBUNTU_DEBUGINFO:
1694	case DSO_BINARY_TYPE__BUILDID_DEBUGINFO:
1695	case DSO_BINARY_TYPE__OPENEMBEDDED_DEBUGINFO:
1696		return !kmod && dso->kernel == DSO_SPACE__USER;
1697
1698	case DSO_BINARY_TYPE__KALLSYMS:
1699	case DSO_BINARY_TYPE__VMLINUX:
1700	case DSO_BINARY_TYPE__KCORE:
1701		return dso->kernel == DSO_SPACE__KERNEL;
1702
1703	case DSO_BINARY_TYPE__GUEST_KALLSYMS:
1704	case DSO_BINARY_TYPE__GUEST_VMLINUX:
1705	case DSO_BINARY_TYPE__GUEST_KCORE:
1706		return dso->kernel == DSO_SPACE__KERNEL_GUEST;
1707
1708	case DSO_BINARY_TYPE__GUEST_KMODULE:
1709	case DSO_BINARY_TYPE__GUEST_KMODULE_COMP:
1710	case DSO_BINARY_TYPE__SYSTEM_PATH_KMODULE:
1711	case DSO_BINARY_TYPE__SYSTEM_PATH_KMODULE_COMP:
1712		/*
1713		 * kernel modules know their symtab type - it's set when
1714		 * creating a module dso in machine__addnew_module_map().
1715		 */
1716		return kmod && dso->symtab_type == type;
1717
1718	case DSO_BINARY_TYPE__BUILD_ID_CACHE:
1719	case DSO_BINARY_TYPE__BUILD_ID_CACHE_DEBUGINFO:
1720		return true;
1721
1722	case DSO_BINARY_TYPE__BPF_PROG_INFO:
1723	case DSO_BINARY_TYPE__BPF_IMAGE:
1724	case DSO_BINARY_TYPE__OOL:
1725	case DSO_BINARY_TYPE__NOT_FOUND:
1726	default:
1727		return false;
1728	}
1729}
1730
1731/* Checks for the existence of the perf-<pid>.map file in two different
1732 * locations.  First, if the process is a separate mount namespace, check in
1733 * that namespace using the pid of the innermost pid namespace.  If's not in a
1734 * namespace, or the file can't be found there, try in the mount namespace of
1735 * the tracing process using our view of its pid.
1736 */
1737static int dso__find_perf_map(char *filebuf, size_t bufsz,
1738			      struct nsinfo **nsip)
1739{
1740	struct nscookie nsc;
1741	struct nsinfo *nsi;
1742	struct nsinfo *nnsi;
1743	int rc = -1;
1744
1745	nsi = *nsip;
1746
1747	if (nsi->need_setns) {
1748		snprintf(filebuf, bufsz, "/tmp/perf-%d.map", nsi->nstgid);
1749		nsinfo__mountns_enter(nsi, &nsc);
1750		rc = access(filebuf, R_OK);
1751		nsinfo__mountns_exit(&nsc);
1752		if (rc == 0)
1753			return rc;
1754	}
1755
1756	nnsi = nsinfo__copy(nsi);
1757	if (nnsi) {
1758		nsinfo__put(nsi);
1759
1760		nnsi->need_setns = false;
1761		snprintf(filebuf, bufsz, "/tmp/perf-%d.map", nnsi->tgid);
1762		*nsip = nnsi;
1763		rc = 0;
1764	}
1765
1766	return rc;
1767}
1768
1769int dso__load(struct dso *dso, struct map *map)
1770{
1771	char *name;
1772	int ret = -1;
1773	u_int i;
1774	struct machine *machine = NULL;
1775	char *root_dir = (char *) "";
1776	int ss_pos = 0;
1777	struct symsrc ss_[2];
1778	struct symsrc *syms_ss = NULL, *runtime_ss = NULL;
1779	bool kmod;
1780	bool perfmap;
1781	struct build_id bid;
1782	struct nscookie nsc;
1783	char newmapname[PATH_MAX];
1784	const char *map_path = dso->long_name;
1785
1786	perfmap = strncmp(dso->name, "/tmp/perf-", 10) == 0;
1787	if (perfmap) {
1788		if (dso->nsinfo && (dso__find_perf_map(newmapname,
1789		    sizeof(newmapname), &dso->nsinfo) == 0)) {
1790			map_path = newmapname;
1791		}
1792	}
1793
1794	nsinfo__mountns_enter(dso->nsinfo, &nsc);
1795	pthread_mutex_lock(&dso->lock);
1796
1797	/* check again under the dso->lock */
1798	if (dso__loaded(dso)) {
1799		ret = 1;
1800		goto out;
1801	}
1802
1803	kmod = dso->symtab_type == DSO_BINARY_TYPE__SYSTEM_PATH_KMODULE ||
1804		dso->symtab_type == DSO_BINARY_TYPE__SYSTEM_PATH_KMODULE_COMP ||
1805		dso->symtab_type == DSO_BINARY_TYPE__GUEST_KMODULE ||
1806		dso->symtab_type == DSO_BINARY_TYPE__GUEST_KMODULE_COMP;
1807
1808	if (dso->kernel && !kmod) {
1809		if (dso->kernel == DSO_SPACE__KERNEL)
1810			ret = dso__load_kernel_sym(dso, map);
1811		else if (dso->kernel == DSO_SPACE__KERNEL_GUEST)
1812			ret = dso__load_guest_kernel_sym(dso, map);
1813
1814		machine = map__kmaps(map)->machine;
1815		if (machine__is(machine, "x86_64"))
1816			machine__map_x86_64_entry_trampolines(machine, dso);
1817		goto out;
1818	}
1819
1820	dso->adjust_symbols = 0;
1821
1822	if (perfmap) {
1823		ret = dso__load_perf_map(map_path, dso);
1824		dso->symtab_type = ret > 0 ? DSO_BINARY_TYPE__JAVA_JIT :
1825					     DSO_BINARY_TYPE__NOT_FOUND;
1826		goto out;
1827	}
1828
1829	if (machine)
1830		root_dir = machine->root_dir;
1831
1832	name = malloc(PATH_MAX);
1833	if (!name)
1834		goto out;
1835
1836	/*
1837	 * Read the build id if possible. This is required for
1838	 * DSO_BINARY_TYPE__BUILDID_DEBUGINFO to work
1839	 */
1840	if (!dso->has_build_id &&
1841	    is_regular_file(dso->long_name)) {
1842	    __symbol__join_symfs(name, PATH_MAX, dso->long_name);
1843		if (filename__read_build_id(name, &bid) > 0)
1844			dso__set_build_id(dso, &bid);
1845	}
1846
1847	/*
1848	 * Iterate over candidate debug images.
1849	 * Keep track of "interesting" ones (those which have a symtab, dynsym,
1850	 * and/or opd section) for processing.
1851	 */
1852	for (i = 0; i < DSO_BINARY_TYPE__SYMTAB_CNT; i++) {
1853		struct symsrc *ss = &ss_[ss_pos];
1854		bool next_slot = false;
1855		bool is_reg;
1856		bool nsexit;
1857		int bfdrc = -1;
1858		int sirc = -1;
1859
1860		enum dso_binary_type symtab_type = binary_type_symtab[i];
1861
1862		nsexit = (symtab_type == DSO_BINARY_TYPE__BUILD_ID_CACHE ||
1863		    symtab_type == DSO_BINARY_TYPE__BUILD_ID_CACHE_DEBUGINFO);
1864
1865		if (!dso__is_compatible_symtab_type(dso, kmod, symtab_type))
1866			continue;
1867
1868		if (dso__read_binary_type_filename(dso, symtab_type,
1869						   root_dir, name, PATH_MAX))
1870			continue;
1871
1872		if (nsexit)
1873			nsinfo__mountns_exit(&nsc);
1874
1875		is_reg = is_regular_file(name);
1876#ifdef HAVE_LIBBFD_SUPPORT
1877		if (is_reg)
1878			bfdrc = dso__load_bfd_symbols(dso, name);
1879#endif
1880		if (is_reg && bfdrc < 0)
1881			sirc = symsrc__init(ss, dso, name, symtab_type);
1882
1883		if (nsexit)
1884			nsinfo__mountns_enter(dso->nsinfo, &nsc);
1885
1886		if (bfdrc == 0) {
1887			ret = 0;
1888			break;
1889		}
1890
1891		if (!is_reg || sirc < 0)
1892			continue;
1893
1894		if (!syms_ss && symsrc__has_symtab(ss)) {
1895			syms_ss = ss;
1896			next_slot = true;
1897			if (!dso->symsrc_filename)
1898				dso->symsrc_filename = strdup(name);
1899		}
1900
1901		if (!runtime_ss && symsrc__possibly_runtime(ss)) {
1902			runtime_ss = ss;
1903			next_slot = true;
1904		}
1905
1906		if (next_slot) {
1907			ss_pos++;
1908
1909			if (syms_ss && runtime_ss)
1910				break;
1911		} else {
1912			symsrc__destroy(ss);
1913		}
1914
1915	}
1916
1917	if (!runtime_ss && !syms_ss)
1918		goto out_free;
1919
1920	if (runtime_ss && !syms_ss) {
1921		syms_ss = runtime_ss;
1922	}
1923
1924	/* We'll have to hope for the best */
1925	if (!runtime_ss && syms_ss)
1926		runtime_ss = syms_ss;
1927
1928	if (syms_ss)
1929		ret = dso__load_sym(dso, map, syms_ss, runtime_ss, kmod);
1930	else
1931		ret = -1;
1932
1933	if (ret > 0) {
1934		int nr_plt;
1935
1936		nr_plt = dso__synthesize_plt_symbols(dso, runtime_ss);
1937		if (nr_plt > 0)
1938			ret += nr_plt;
1939	}
1940
1941	for (; ss_pos > 0; ss_pos--)
1942		symsrc__destroy(&ss_[ss_pos - 1]);
1943out_free:
1944	free(name);
1945	if (ret < 0 && strstr(dso->name, " (deleted)") != NULL)
1946		ret = 0;
1947out:
1948	dso__set_loaded(dso);
1949	pthread_mutex_unlock(&dso->lock);
1950	nsinfo__mountns_exit(&nsc);
1951
1952	return ret;
1953}
1954
1955static int map__strcmp(const void *a, const void *b)
1956{
1957	const struct map *ma = *(const struct map **)a, *mb = *(const struct map **)b;
1958	return strcmp(ma->dso->short_name, mb->dso->short_name);
1959}
1960
1961static int map__strcmp_name(const void *name, const void *b)
1962{
1963	const struct map *map = *(const struct map **)b;
1964	return strcmp(name, map->dso->short_name);
1965}
1966
1967void __maps__sort_by_name(struct maps *maps)
1968{
1969	qsort(maps->maps_by_name, maps->nr_maps, sizeof(struct map *), map__strcmp);
1970}
1971
1972static int map__groups__sort_by_name_from_rbtree(struct maps *maps)
1973{
1974	struct map *map;
1975	struct map **maps_by_name = realloc(maps->maps_by_name, maps->nr_maps * sizeof(map));
1976	int i = 0;
1977
1978	if (maps_by_name == NULL)
1979		return -1;
1980
1981	maps->maps_by_name = maps_by_name;
1982	maps->nr_maps_allocated = maps->nr_maps;
1983
1984	maps__for_each_entry(maps, map)
1985		maps_by_name[i++] = map;
1986
1987	__maps__sort_by_name(maps);
1988	return 0;
1989}
1990
1991static struct map *__maps__find_by_name(struct maps *maps, const char *name)
1992{
1993	struct map **mapp;
1994
1995	if (maps->maps_by_name == NULL &&
1996	    map__groups__sort_by_name_from_rbtree(maps))
1997		return NULL;
1998
1999	mapp = bsearch(name, maps->maps_by_name, maps->nr_maps, sizeof(*mapp), map__strcmp_name);
2000	if (mapp)
2001		return *mapp;
2002	return NULL;
2003}
2004
2005struct map *maps__find_by_name(struct maps *maps, const char *name)
2006{
2007	struct map *map;
2008
2009	down_read(&maps->lock);
2010
2011	if (maps->last_search_by_name && strcmp(maps->last_search_by_name->dso->short_name, name) == 0) {
2012		map = maps->last_search_by_name;
2013		goto out_unlock;
2014	}
2015	/*
2016	 * If we have maps->maps_by_name, then the name isn't in the rbtree,
2017	 * as maps->maps_by_name mirrors the rbtree when lookups by name are
2018	 * made.
2019	 */
2020	map = __maps__find_by_name(maps, name);
2021	if (map || maps->maps_by_name != NULL)
2022		goto out_unlock;
2023
2024	/* Fallback to traversing the rbtree... */
2025	maps__for_each_entry(maps, map)
2026		if (strcmp(map->dso->short_name, name) == 0) {
2027			maps->last_search_by_name = map;
2028			goto out_unlock;
2029		}
2030
2031	map = NULL;
2032
2033out_unlock:
2034	up_read(&maps->lock);
2035	return map;
2036}
2037
2038int dso__load_vmlinux(struct dso *dso, struct map *map,
2039		      const char *vmlinux, bool vmlinux_allocated)
2040{
2041	int err = -1;
2042	struct symsrc ss;
2043	char symfs_vmlinux[PATH_MAX];
2044	enum dso_binary_type symtab_type;
2045
2046	if (vmlinux[0] == '/')
2047		snprintf(symfs_vmlinux, sizeof(symfs_vmlinux), "%s", vmlinux);
2048	else
2049		symbol__join_symfs(symfs_vmlinux, vmlinux);
2050
2051	if (dso->kernel == DSO_SPACE__KERNEL_GUEST)
2052		symtab_type = DSO_BINARY_TYPE__GUEST_VMLINUX;
2053	else
2054		symtab_type = DSO_BINARY_TYPE__VMLINUX;
2055
2056	if (symsrc__init(&ss, dso, symfs_vmlinux, symtab_type))
2057		return -1;
2058
2059	err = dso__load_sym(dso, map, &ss, &ss, 0);
2060	symsrc__destroy(&ss);
2061
2062	if (err > 0) {
2063		if (dso->kernel == DSO_SPACE__KERNEL_GUEST)
2064			dso->binary_type = DSO_BINARY_TYPE__GUEST_VMLINUX;
2065		else
2066			dso->binary_type = DSO_BINARY_TYPE__VMLINUX;
2067		dso__set_long_name(dso, vmlinux, vmlinux_allocated);
2068		dso__set_loaded(dso);
2069		pr_debug("Using %s for symbols\n", symfs_vmlinux);
2070	}
2071
2072	return err;
2073}
2074
2075int dso__load_vmlinux_path(struct dso *dso, struct map *map)
2076{
2077	int i, err = 0;
2078	char *filename = NULL;
2079
2080	pr_debug("Looking at the vmlinux_path (%d entries long)\n",
2081		 vmlinux_path__nr_entries + 1);
2082
2083	for (i = 0; i < vmlinux_path__nr_entries; ++i) {
2084		err = dso__load_vmlinux(dso, map, vmlinux_path[i], false);
2085		if (err > 0)
2086			goto out;
2087	}
2088
2089	if (!symbol_conf.ignore_vmlinux_buildid)
2090		filename = dso__build_id_filename(dso, NULL, 0, false);
2091	if (filename != NULL) {
2092		err = dso__load_vmlinux(dso, map, filename, true);
2093		if (err > 0)
2094			goto out;
2095		free(filename);
2096	}
2097out:
2098	return err;
2099}
2100
2101static bool visible_dir_filter(const char *name, struct dirent *d)
2102{
2103	if (d->d_type != DT_DIR)
2104		return false;
2105	return lsdir_no_dot_filter(name, d);
2106}
2107
2108static int find_matching_kcore(struct map *map, char *dir, size_t dir_sz)
2109{
2110	char kallsyms_filename[PATH_MAX];
2111	int ret = -1;
2112	struct strlist *dirs;
2113	struct str_node *nd;
2114
2115	dirs = lsdir(dir, visible_dir_filter);
2116	if (!dirs)
2117		return -1;
2118
2119	strlist__for_each_entry(nd, dirs) {
2120		scnprintf(kallsyms_filename, sizeof(kallsyms_filename),
2121			  "%s/%s/kallsyms", dir, nd->s);
2122		if (!validate_kcore_addresses(kallsyms_filename, map)) {
2123			strlcpy(dir, kallsyms_filename, dir_sz);
2124			ret = 0;
2125			break;
2126		}
2127	}
2128
2129	strlist__delete(dirs);
2130
2131	return ret;
2132}
2133
2134/*
2135 * Use open(O_RDONLY) to check readability directly instead of access(R_OK)
2136 * since access(R_OK) only checks with real UID/GID but open() use effective
2137 * UID/GID and actual capabilities (e.g. /proc/kcore requires CAP_SYS_RAWIO).
2138 */
2139static bool filename__readable(const char *file)
2140{
2141	int fd = open(file, O_RDONLY);
2142	if (fd < 0)
2143		return false;
2144	close(fd);
2145	return true;
2146}
2147
2148static char *dso__find_kallsyms(struct dso *dso, struct map *map)
2149{
2150	struct build_id bid;
2151	char sbuild_id[SBUILD_ID_SIZE];
2152	bool is_host = false;
2153	char path[PATH_MAX];
2154
2155	if (!dso->has_build_id) {
2156		/*
2157		 * Last resort, if we don't have a build-id and couldn't find
2158		 * any vmlinux file, try the running kernel kallsyms table.
2159		 */
2160		goto proc_kallsyms;
2161	}
2162
2163	if (sysfs__read_build_id("/sys/kernel/notes", &bid) == 0)
2164		is_host = dso__build_id_equal(dso, &bid);
2165
2166	/* Try a fast path for /proc/kallsyms if possible */
2167	if (is_host) {
2168		/*
2169		 * Do not check the build-id cache, unless we know we cannot use
2170		 * /proc/kcore or module maps don't match to /proc/kallsyms.
2171		 * To check readability of /proc/kcore, do not use access(R_OK)
2172		 * since /proc/kcore requires CAP_SYS_RAWIO to read and access
2173		 * can't check it.
2174		 */
2175		if (filename__readable("/proc/kcore") &&
2176		    !validate_kcore_addresses("/proc/kallsyms", map))
2177			goto proc_kallsyms;
2178	}
2179
2180	build_id__sprintf(&dso->bid, sbuild_id);
2181
2182	/* Find kallsyms in build-id cache with kcore */
2183	scnprintf(path, sizeof(path), "%s/%s/%s",
2184		  buildid_dir, DSO__NAME_KCORE, sbuild_id);
2185
2186	if (!find_matching_kcore(map, path, sizeof(path)))
2187		return strdup(path);
2188
2189	/* Use current /proc/kallsyms if possible */
2190	if (is_host) {
2191proc_kallsyms:
2192		return strdup("/proc/kallsyms");
2193	}
2194
2195	/* Finally, find a cache of kallsyms */
2196	if (!build_id_cache__kallsyms_path(sbuild_id, path, sizeof(path))) {
2197		pr_err("No kallsyms or vmlinux with build-id %s was found\n",
2198		       sbuild_id);
2199		return NULL;
2200	}
2201
2202	return strdup(path);
2203}
2204
2205static int dso__load_kernel_sym(struct dso *dso, struct map *map)
2206{
2207	int err;
2208	const char *kallsyms_filename = NULL;
2209	char *kallsyms_allocated_filename = NULL;
2210	/*
2211	 * Step 1: if the user specified a kallsyms or vmlinux filename, use
2212	 * it and only it, reporting errors to the user if it cannot be used.
2213	 *
2214	 * For instance, try to analyse an ARM perf.data file _without_ a
2215	 * build-id, or if the user specifies the wrong path to the right
2216	 * vmlinux file, obviously we can't fallback to another vmlinux (a
2217	 * x86_86 one, on the machine where analysis is being performed, say),
2218	 * or worse, /proc/kallsyms.
2219	 *
2220	 * If the specified file _has_ a build-id and there is a build-id
2221	 * section in the perf.data file, we will still do the expected
2222	 * validation in dso__load_vmlinux and will bail out if they don't
2223	 * match.
2224	 */
2225	if (symbol_conf.kallsyms_name != NULL) {
2226		kallsyms_filename = symbol_conf.kallsyms_name;
2227		goto do_kallsyms;
2228	}
2229
2230	if (!symbol_conf.ignore_vmlinux && symbol_conf.vmlinux_name != NULL) {
2231		return dso__load_vmlinux(dso, map, symbol_conf.vmlinux_name, false);
2232	}
2233
2234	if (!symbol_conf.ignore_vmlinux && vmlinux_path != NULL) {
2235		err = dso__load_vmlinux_path(dso, map);
2236		if (err > 0)
2237			return err;
2238	}
2239
2240	/* do not try local files if a symfs was given */
2241	if (symbol_conf.symfs[0] != 0)
2242		return -1;
2243
2244	kallsyms_allocated_filename = dso__find_kallsyms(dso, map);
2245	if (!kallsyms_allocated_filename)
2246		return -1;
2247
2248	kallsyms_filename = kallsyms_allocated_filename;
2249
2250do_kallsyms:
2251	err = dso__load_kallsyms(dso, kallsyms_filename, map);
2252	if (err > 0)
2253		pr_debug("Using %s for symbols\n", kallsyms_filename);
2254	free(kallsyms_allocated_filename);
2255
2256	if (err > 0 && !dso__is_kcore(dso)) {
2257		dso->binary_type = DSO_BINARY_TYPE__KALLSYMS;
2258		dso__set_long_name(dso, DSO__NAME_KALLSYMS, false);
2259		map__fixup_start(map);
2260		map__fixup_end(map);
2261	}
2262
2263	return err;
2264}
2265
2266static int dso__load_guest_kernel_sym(struct dso *dso, struct map *map)
2267{
2268	int err;
2269	const char *kallsyms_filename = NULL;
2270	struct machine *machine = map__kmaps(map)->machine;
2271	char path[PATH_MAX];
2272
2273	if (machine__is_default_guest(machine)) {
2274		/*
2275		 * if the user specified a vmlinux filename, use it and only
2276		 * it, reporting errors to the user if it cannot be used.
2277		 * Or use file guest_kallsyms inputted by user on commandline
2278		 */
2279		if (symbol_conf.default_guest_vmlinux_name != NULL) {
2280			err = dso__load_vmlinux(dso, map,
2281						symbol_conf.default_guest_vmlinux_name,
2282						false);
2283			return err;
2284		}
2285
2286		kallsyms_filename = symbol_conf.default_guest_kallsyms;
2287		if (!kallsyms_filename)
2288			return -1;
2289	} else {
2290		sprintf(path, "%s/proc/kallsyms", machine->root_dir);
2291		kallsyms_filename = path;
2292	}
2293
2294	err = dso__load_kallsyms(dso, kallsyms_filename, map);
2295	if (err > 0)
2296		pr_debug("Using %s for symbols\n", kallsyms_filename);
2297	if (err > 0 && !dso__is_kcore(dso)) {
2298		dso->binary_type = DSO_BINARY_TYPE__GUEST_KALLSYMS;
2299		dso__set_long_name(dso, machine->mmap_name, false);
2300		map__fixup_start(map);
2301		map__fixup_end(map);
2302	}
2303
2304	return err;
2305}
2306
2307static void vmlinux_path__exit(void)
2308{
2309	while (--vmlinux_path__nr_entries >= 0)
2310		zfree(&vmlinux_path[vmlinux_path__nr_entries]);
2311	vmlinux_path__nr_entries = 0;
2312
2313	zfree(&vmlinux_path);
2314}
2315
2316static const char * const vmlinux_paths[] = {
2317	"vmlinux",
2318	"/boot/vmlinux"
2319};
2320
2321static const char * const vmlinux_paths_upd[] = {
2322	"/boot/vmlinux-%s",
2323	"/usr/lib/debug/boot/vmlinux-%s",
2324	"/lib/modules/%s/build/vmlinux",
2325	"/usr/lib/debug/lib/modules/%s/vmlinux",
2326	"/usr/lib/debug/boot/vmlinux-%s.debug"
2327};
2328
2329static int vmlinux_path__add(const char *new_entry)
2330{
2331	vmlinux_path[vmlinux_path__nr_entries] = strdup(new_entry);
2332	if (vmlinux_path[vmlinux_path__nr_entries] == NULL)
2333		return -1;
2334	++vmlinux_path__nr_entries;
2335
2336	return 0;
2337}
2338
2339static int vmlinux_path__init(struct perf_env *env)
2340{
2341	struct utsname uts;
2342	char bf[PATH_MAX];
2343	char *kernel_version;
2344	unsigned int i;
2345
2346	vmlinux_path = malloc(sizeof(char *) * (ARRAY_SIZE(vmlinux_paths) +
2347			      ARRAY_SIZE(vmlinux_paths_upd)));
2348	if (vmlinux_path == NULL)
2349		return -1;
2350
2351	for (i = 0; i < ARRAY_SIZE(vmlinux_paths); i++)
2352		if (vmlinux_path__add(vmlinux_paths[i]) < 0)
2353			goto out_fail;
2354
2355	/* only try kernel version if no symfs was given */
2356	if (symbol_conf.symfs[0] != 0)
2357		return 0;
2358
2359	if (env) {
2360		kernel_version = env->os_release;
2361	} else {
2362		if (uname(&uts) < 0)
2363			goto out_fail;
2364
2365		kernel_version = uts.release;
2366	}
2367
2368	for (i = 0; i < ARRAY_SIZE(vmlinux_paths_upd); i++) {
2369		snprintf(bf, sizeof(bf), vmlinux_paths_upd[i], kernel_version);
2370		if (vmlinux_path__add(bf) < 0)
2371			goto out_fail;
2372	}
2373
2374	return 0;
2375
2376out_fail:
2377	vmlinux_path__exit();
2378	return -1;
2379}
2380
2381int setup_list(struct strlist **list, const char *list_str,
2382		      const char *list_name)
2383{
2384	if (list_str == NULL)
2385		return 0;
2386
2387	*list = strlist__new(list_str, NULL);
2388	if (!*list) {
2389		pr_err("problems parsing %s list\n", list_name);
2390		return -1;
2391	}
2392
2393	symbol_conf.has_filter = true;
2394	return 0;
2395}
2396
2397int setup_intlist(struct intlist **list, const char *list_str,
2398		  const char *list_name)
2399{
2400	if (list_str == NULL)
2401		return 0;
2402
2403	*list = intlist__new(list_str);
2404	if (!*list) {
2405		pr_err("problems parsing %s list\n", list_name);
2406		return -1;
2407	}
2408	return 0;
2409}
2410
2411static bool symbol__read_kptr_restrict(void)
2412{
2413	bool value = false;
2414	FILE *fp = fopen("/proc/sys/kernel/kptr_restrict", "r");
2415
2416	if (fp != NULL) {
2417		char line[8];
2418
2419		if (fgets(line, sizeof(line), fp) != NULL)
2420			value = perf_cap__capable(CAP_SYSLOG) ?
2421					(atoi(line) >= 2) :
2422					(atoi(line) != 0);
2423
2424		fclose(fp);
2425	}
2426
2427	/* Per kernel/kallsyms.c:
2428	 * we also restrict when perf_event_paranoid > 1 w/o CAP_SYSLOG
2429	 */
2430	if (perf_event_paranoid() > 1 && !perf_cap__capable(CAP_SYSLOG))
2431		value = true;
2432
2433	return value;
2434}
2435
2436int symbol__annotation_init(void)
2437{
2438	if (symbol_conf.init_annotation)
2439		return 0;
2440
2441	if (symbol_conf.initialized) {
2442		pr_err("Annotation needs to be init before symbol__init()\n");
2443		return -1;
2444	}
2445
2446	symbol_conf.priv_size += sizeof(struct annotation);
2447	symbol_conf.init_annotation = true;
2448	return 0;
2449}
2450
2451int symbol__init(struct perf_env *env)
2452{
2453	const char *symfs;
2454
2455	if (symbol_conf.initialized)
2456		return 0;
2457
2458	symbol_conf.priv_size = PERF_ALIGN(symbol_conf.priv_size, sizeof(u64));
2459
2460	symbol__elf_init();
2461
2462	if (symbol_conf.sort_by_name)
2463		symbol_conf.priv_size += (sizeof(struct symbol_name_rb_node) -
2464					  sizeof(struct symbol));
2465
2466	if (symbol_conf.try_vmlinux_path && vmlinux_path__init(env) < 0)
2467		return -1;
2468
2469	if (symbol_conf.field_sep && *symbol_conf.field_sep == '.') {
2470		pr_err("'.' is the only non valid --field-separator argument\n");
2471		return -1;
2472	}
2473
2474	if (setup_list(&symbol_conf.dso_list,
2475		       symbol_conf.dso_list_str, "dso") < 0)
2476		return -1;
2477
2478	if (setup_list(&symbol_conf.comm_list,
2479		       symbol_conf.comm_list_str, "comm") < 0)
2480		goto out_free_dso_list;
2481
2482	if (setup_intlist(&symbol_conf.pid_list,
2483		       symbol_conf.pid_list_str, "pid") < 0)
2484		goto out_free_comm_list;
2485
2486	if (setup_intlist(&symbol_conf.tid_list,
2487		       symbol_conf.tid_list_str, "tid") < 0)
2488		goto out_free_pid_list;
2489
2490	if (setup_list(&symbol_conf.sym_list,
2491		       symbol_conf.sym_list_str, "symbol") < 0)
2492		goto out_free_tid_list;
2493
2494	if (setup_list(&symbol_conf.bt_stop_list,
2495		       symbol_conf.bt_stop_list_str, "symbol") < 0)
2496		goto out_free_sym_list;
2497
2498	/*
2499	 * A path to symbols of "/" is identical to ""
2500	 * reset here for simplicity.
2501	 */
2502	symfs = realpath(symbol_conf.symfs, NULL);
2503	if (symfs == NULL)
2504		symfs = symbol_conf.symfs;
2505	if (strcmp(symfs, "/") == 0)
2506		symbol_conf.symfs = "";
2507	if (symfs != symbol_conf.symfs)
2508		free((void *)symfs);
2509
2510	symbol_conf.kptr_restrict = symbol__read_kptr_restrict();
2511
2512	symbol_conf.initialized = true;
2513	return 0;
2514
2515out_free_sym_list:
2516	strlist__delete(symbol_conf.sym_list);
2517out_free_tid_list:
2518	intlist__delete(symbol_conf.tid_list);
2519out_free_pid_list:
2520	intlist__delete(symbol_conf.pid_list);
2521out_free_comm_list:
2522	strlist__delete(symbol_conf.comm_list);
2523out_free_dso_list:
2524	strlist__delete(symbol_conf.dso_list);
2525	return -1;
2526}
2527
2528void symbol__exit(void)
2529{
2530	if (!symbol_conf.initialized)
2531		return;
2532	strlist__delete(symbol_conf.bt_stop_list);
2533	strlist__delete(symbol_conf.sym_list);
2534	strlist__delete(symbol_conf.dso_list);
2535	strlist__delete(symbol_conf.comm_list);
2536	intlist__delete(symbol_conf.tid_list);
2537	intlist__delete(symbol_conf.pid_list);
2538	vmlinux_path__exit();
2539	symbol_conf.sym_list = symbol_conf.dso_list = symbol_conf.comm_list = NULL;
2540	symbol_conf.bt_stop_list = NULL;
2541	symbol_conf.initialized = false;
2542}
2543
2544int symbol__config_symfs(const struct option *opt __maybe_unused,
2545			 const char *dir, int unset __maybe_unused)
2546{
2547	char *bf = NULL;
2548	int ret;
2549
2550	symbol_conf.symfs = strdup(dir);
2551	if (symbol_conf.symfs == NULL)
2552		return -ENOMEM;
2553
2554	/* skip the locally configured cache if a symfs is given, and
2555	 * config buildid dir to symfs/.debug
2556	 */
2557	ret = asprintf(&bf, "%s/%s", dir, ".debug");
2558	if (ret < 0)
2559		return -ENOMEM;
2560
2561	set_buildid_dir(bf);
2562
2563	free(bf);
2564	return 0;
2565}
2566
2567struct mem_info *mem_info__get(struct mem_info *mi)
2568{
2569	if (mi)
2570		refcount_inc(&mi->refcnt);
2571	return mi;
2572}
2573
2574void mem_info__put(struct mem_info *mi)
2575{
2576	if (mi && refcount_dec_and_test(&mi->refcnt))
2577		free(mi);
2578}
2579
2580struct mem_info *mem_info__new(void)
2581{
2582	struct mem_info *mi = zalloc(sizeof(*mi));
2583
2584	if (mi)
2585		refcount_set(&mi->refcnt, 1);
2586	return mi;
2587}
2588