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 "mem-info.h"
31 #include "symsrc.h"
32 #include "strlist.h"
33 #include "intlist.h"
34 #include "namespaces.h"
35 #include "header.h"
36 #include "path.h"
37 #include <linux/ctype.h>
38 #include <linux/zalloc.h>
39 
40 #include <elf.h>
41 #include <limits.h>
42 #include <symbol/kallsyms.h>
43 #include <sys/utsname.h>
44 
45 static int dso__load_kernel_sym(struct dso *dso, struct map *map);
46 static int dso__load_guest_kernel_sym(struct dso *dso, struct map *map);
47 static bool symbol__is_idle(const char *name);
48 
49 int vmlinux_path__nr_entries;
50 char **vmlinux_path;
51 
52 struct symbol_conf symbol_conf = {
53 	.nanosecs		= false,
54 	.use_modules		= true,
55 	.try_vmlinux_path	= true,
56 	.demangle		= true,
57 	.demangle_kernel	= false,
58 	.cumulate_callchain	= true,
59 	.time_quantum		= 100 * NSEC_PER_MSEC, /* 100ms */
60 	.show_hist_headers	= true,
61 	.symfs			= "",
62 	.event_group		= true,
63 	.inline_name		= true,
64 	.res_sample		= 0,
65 };
66 
67 struct map_list_node {
68 	struct list_head node;
69 	struct map *map;
70 };
71 
map_list_node__new(void)72 static struct map_list_node *map_list_node__new(void)
73 {
74 	return malloc(sizeof(struct map_list_node));
75 }
76 
77 static enum dso_binary_type binary_type_symtab[] = {
78 	DSO_BINARY_TYPE__KALLSYMS,
79 	DSO_BINARY_TYPE__GUEST_KALLSYMS,
80 	DSO_BINARY_TYPE__JAVA_JIT,
81 	DSO_BINARY_TYPE__DEBUGLINK,
82 	DSO_BINARY_TYPE__BUILD_ID_CACHE,
83 	DSO_BINARY_TYPE__BUILD_ID_CACHE_DEBUGINFO,
84 	DSO_BINARY_TYPE__FEDORA_DEBUGINFO,
85 	DSO_BINARY_TYPE__UBUNTU_DEBUGINFO,
86 	DSO_BINARY_TYPE__BUILDID_DEBUGINFO,
87 	DSO_BINARY_TYPE__SYSTEM_PATH_DSO,
88 	DSO_BINARY_TYPE__GUEST_KMODULE,
89 	DSO_BINARY_TYPE__GUEST_KMODULE_COMP,
90 	DSO_BINARY_TYPE__SYSTEM_PATH_KMODULE,
91 	DSO_BINARY_TYPE__SYSTEM_PATH_KMODULE_COMP,
92 	DSO_BINARY_TYPE__OPENEMBEDDED_DEBUGINFO,
93 	DSO_BINARY_TYPE__MIXEDUP_UBUNTU_DEBUGINFO,
94 	DSO_BINARY_TYPE__NOT_FOUND,
95 };
96 
97 #define DSO_BINARY_TYPE__SYMTAB_CNT ARRAY_SIZE(binary_type_symtab)
98 
symbol_type__filter(char symbol_type)99 static bool symbol_type__filter(char symbol_type)
100 {
101 	symbol_type = toupper(symbol_type);
102 	return symbol_type == 'T' || symbol_type == 'W' || symbol_type == 'D' || symbol_type == 'B';
103 }
104 
prefix_underscores_count(const char * str)105 static int prefix_underscores_count(const char *str)
106 {
107 	const char *tail = str;
108 
109 	while (*tail == '_')
110 		tail++;
111 
112 	return tail - str;
113 }
114 
arch__normalize_symbol_name(const char * name)115 const char * __weak arch__normalize_symbol_name(const char *name)
116 {
117 	return name;
118 }
119 
arch__compare_symbol_names(const char * namea,const char * nameb)120 int __weak arch__compare_symbol_names(const char *namea, const char *nameb)
121 {
122 	return strcmp(namea, nameb);
123 }
124 
arch__compare_symbol_names_n(const char * namea,const char * nameb,unsigned int n)125 int __weak arch__compare_symbol_names_n(const char *namea, const char *nameb,
126 					unsigned int n)
127 {
128 	return strncmp(namea, nameb, n);
129 }
130 
arch__choose_best_symbol(struct symbol * syma,struct symbol * symb __maybe_unused)131 int __weak arch__choose_best_symbol(struct symbol *syma,
132 				    struct symbol *symb __maybe_unused)
133 {
134 	/* Avoid "SyS" kernel syscall aliases */
135 	if (strlen(syma->name) >= 3 && !strncmp(syma->name, "SyS", 3))
136 		return SYMBOL_B;
137 	if (strlen(syma->name) >= 10 && !strncmp(syma->name, "compat_SyS", 10))
138 		return SYMBOL_B;
139 
140 	return SYMBOL_A;
141 }
142 
choose_best_symbol(struct symbol * syma,struct symbol * symb)143 static int choose_best_symbol(struct symbol *syma, struct symbol *symb)
144 {
145 	s64 a;
146 	s64 b;
147 	size_t na, nb;
148 
149 	/* Prefer a symbol with non zero length */
150 	a = syma->end - syma->start;
151 	b = symb->end - symb->start;
152 	if ((b == 0) && (a > 0))
153 		return SYMBOL_A;
154 	else if ((a == 0) && (b > 0))
155 		return SYMBOL_B;
156 
157 	if (syma->type != symb->type) {
158 		if (syma->type == STT_NOTYPE)
159 			return SYMBOL_B;
160 		if (symb->type == STT_NOTYPE)
161 			return SYMBOL_A;
162 	}
163 
164 	/* Prefer a non weak symbol over a weak one */
165 	a = syma->binding == STB_WEAK;
166 	b = symb->binding == STB_WEAK;
167 	if (b && !a)
168 		return SYMBOL_A;
169 	if (a && !b)
170 		return SYMBOL_B;
171 
172 	/* Prefer a global symbol over a non global one */
173 	a = syma->binding == STB_GLOBAL;
174 	b = symb->binding == STB_GLOBAL;
175 	if (a && !b)
176 		return SYMBOL_A;
177 	if (b && !a)
178 		return SYMBOL_B;
179 
180 	/* Prefer a symbol with less underscores */
181 	a = prefix_underscores_count(syma->name);
182 	b = prefix_underscores_count(symb->name);
183 	if (b > a)
184 		return SYMBOL_A;
185 	else if (a > b)
186 		return SYMBOL_B;
187 
188 	/* Choose the symbol with the longest name */
189 	na = strlen(syma->name);
190 	nb = strlen(symb->name);
191 	if (na > nb)
192 		return SYMBOL_A;
193 	else if (na < nb)
194 		return SYMBOL_B;
195 
196 	return arch__choose_best_symbol(syma, symb);
197 }
198 
symbols__fixup_duplicate(struct rb_root_cached * symbols)199 void symbols__fixup_duplicate(struct rb_root_cached *symbols)
200 {
201 	struct rb_node *nd;
202 	struct symbol *curr, *next;
203 
204 	if (symbol_conf.allow_aliases)
205 		return;
206 
207 	nd = rb_first_cached(symbols);
208 
209 	while (nd) {
210 		curr = rb_entry(nd, struct symbol, rb_node);
211 again:
212 		nd = rb_next(&curr->rb_node);
213 		if (!nd)
214 			break;
215 
216 		next = rb_entry(nd, struct symbol, rb_node);
217 		if (curr->start != next->start)
218 			continue;
219 
220 		if (choose_best_symbol(curr, next) == SYMBOL_A) {
221 			if (next->type == STT_GNU_IFUNC)
222 				curr->ifunc_alias = true;
223 			rb_erase_cached(&next->rb_node, symbols);
224 			symbol__delete(next);
225 			goto again;
226 		} else {
227 			if (curr->type == STT_GNU_IFUNC)
228 				next->ifunc_alias = true;
229 			nd = rb_next(&curr->rb_node);
230 			rb_erase_cached(&curr->rb_node, symbols);
231 			symbol__delete(curr);
232 		}
233 	}
234 }
235 
236 /* Update zero-sized symbols using the address of the next symbol */
symbols__fixup_end(struct rb_root_cached * symbols,bool is_kallsyms)237 void symbols__fixup_end(struct rb_root_cached *symbols, bool is_kallsyms)
238 {
239 	struct rb_node *nd, *prevnd = rb_first_cached(symbols);
240 	struct symbol *curr, *prev;
241 
242 	if (prevnd == NULL)
243 		return;
244 
245 	curr = rb_entry(prevnd, struct symbol, rb_node);
246 
247 	for (nd = rb_next(prevnd); nd; nd = rb_next(nd)) {
248 		prev = curr;
249 		curr = rb_entry(nd, struct symbol, rb_node);
250 
251 		/*
252 		 * On some architecture kernel text segment start is located at
253 		 * some low memory address, while modules are located at high
254 		 * memory addresses (or vice versa).  The gap between end of
255 		 * kernel text segment and beginning of first module's text
256 		 * segment is very big.  Therefore do not fill this gap and do
257 		 * not assign it to the kernel dso map (kallsyms).
258 		 *
259 		 * Also BPF code can be allocated separately from text segments
260 		 * and modules.  So the last entry in a module should not fill
261 		 * the gap too.
262 		 *
263 		 * In kallsyms, it determines module symbols using '[' character
264 		 * like in:
265 		 *   ffffffffc1937000 T hdmi_driver_init  [snd_hda_codec_hdmi]
266 		 */
267 		if (prev->end == prev->start) {
268 			const char *prev_mod;
269 			const char *curr_mod;
270 
271 			if (!is_kallsyms) {
272 				prev->end = curr->start;
273 				continue;
274 			}
275 
276 			prev_mod = strchr(prev->name, '[');
277 			curr_mod = strchr(curr->name, '[');
278 
279 			/* Last kernel/module symbol mapped to end of page */
280 			if (!prev_mod != !curr_mod)
281 				prev->end = roundup(prev->end + 4096, 4096);
282 			/* Last symbol in the previous module */
283 			else if (prev_mod && strcmp(prev_mod, curr_mod))
284 				prev->end = roundup(prev->end + 4096, 4096);
285 			else
286 				prev->end = curr->start;
287 
288 			pr_debug4("%s sym:%s end:%#" PRIx64 "\n",
289 				  __func__, prev->name, prev->end);
290 		}
291 	}
292 
293 	/* Last entry */
294 	if (curr->end == curr->start)
295 		curr->end = roundup(curr->start, 4096) + 4096;
296 }
297 
symbol__new(u64 start,u64 len,u8 binding,u8 type,const char * name)298 struct symbol *symbol__new(u64 start, u64 len, u8 binding, u8 type, const char *name)
299 {
300 	size_t namelen = strlen(name) + 1;
301 	struct symbol *sym = calloc(1, (symbol_conf.priv_size +
302 					sizeof(*sym) + namelen));
303 	if (sym == NULL)
304 		return NULL;
305 
306 	if (symbol_conf.priv_size) {
307 		if (symbol_conf.init_annotation) {
308 			struct annotation *notes = (void *)sym;
309 			annotation__init(notes);
310 		}
311 		sym = ((void *)sym) + symbol_conf.priv_size;
312 	}
313 
314 	sym->start   = start;
315 	sym->end     = len ? start + len : start;
316 	sym->type    = type;
317 	sym->binding = binding;
318 	sym->namelen = namelen - 1;
319 
320 	pr_debug4("%s: %s %#" PRIx64 "-%#" PRIx64 "\n",
321 		  __func__, name, start, sym->end);
322 	memcpy(sym->name, name, namelen);
323 
324 	return sym;
325 }
326 
symbol__delete(struct symbol * sym)327 void symbol__delete(struct symbol *sym)
328 {
329 	if (symbol_conf.priv_size) {
330 		if (symbol_conf.init_annotation) {
331 			struct annotation *notes = symbol__annotation(sym);
332 
333 			annotation__exit(notes);
334 		}
335 	}
336 	free(((void *)sym) - symbol_conf.priv_size);
337 }
338 
symbols__delete(struct rb_root_cached * symbols)339 void symbols__delete(struct rb_root_cached *symbols)
340 {
341 	struct symbol *pos;
342 	struct rb_node *next = rb_first_cached(symbols);
343 
344 	while (next) {
345 		pos = rb_entry(next, struct symbol, rb_node);
346 		next = rb_next(&pos->rb_node);
347 		rb_erase_cached(&pos->rb_node, symbols);
348 		symbol__delete(pos);
349 	}
350 }
351 
__symbols__insert(struct rb_root_cached * symbols,struct symbol * sym,bool kernel)352 void __symbols__insert(struct rb_root_cached *symbols,
353 		       struct symbol *sym, bool kernel)
354 {
355 	struct rb_node **p = &symbols->rb_root.rb_node;
356 	struct rb_node *parent = NULL;
357 	const u64 ip = sym->start;
358 	struct symbol *s;
359 	bool leftmost = true;
360 
361 	if (kernel) {
362 		const char *name = sym->name;
363 		/*
364 		 * ppc64 uses function descriptors and appends a '.' to the
365 		 * start of every instruction address. Remove it.
366 		 */
367 		if (name[0] == '.')
368 			name++;
369 		sym->idle = symbol__is_idle(name);
370 	}
371 
372 	while (*p != NULL) {
373 		parent = *p;
374 		s = rb_entry(parent, struct symbol, rb_node);
375 		if (ip < s->start)
376 			p = &(*p)->rb_left;
377 		else {
378 			p = &(*p)->rb_right;
379 			leftmost = false;
380 		}
381 	}
382 	rb_link_node(&sym->rb_node, parent, p);
383 	rb_insert_color_cached(&sym->rb_node, symbols, leftmost);
384 }
385 
symbols__insert(struct rb_root_cached * symbols,struct symbol * sym)386 void symbols__insert(struct rb_root_cached *symbols, struct symbol *sym)
387 {
388 	__symbols__insert(symbols, sym, false);
389 }
390 
symbols__find(struct rb_root_cached * symbols,u64 ip)391 static struct symbol *symbols__find(struct rb_root_cached *symbols, u64 ip)
392 {
393 	struct rb_node *n;
394 
395 	if (symbols == NULL)
396 		return NULL;
397 
398 	n = symbols->rb_root.rb_node;
399 
400 	while (n) {
401 		struct symbol *s = rb_entry(n, struct symbol, rb_node);
402 
403 		if (ip < s->start)
404 			n = n->rb_left;
405 		else if (ip > s->end || (ip == s->end && ip != s->start))
406 			n = n->rb_right;
407 		else
408 			return s;
409 	}
410 
411 	return NULL;
412 }
413 
symbols__first(struct rb_root_cached * symbols)414 static struct symbol *symbols__first(struct rb_root_cached *symbols)
415 {
416 	struct rb_node *n = rb_first_cached(symbols);
417 
418 	if (n)
419 		return rb_entry(n, struct symbol, rb_node);
420 
421 	return NULL;
422 }
423 
symbols__last(struct rb_root_cached * symbols)424 static struct symbol *symbols__last(struct rb_root_cached *symbols)
425 {
426 	struct rb_node *n = rb_last(&symbols->rb_root);
427 
428 	if (n)
429 		return rb_entry(n, struct symbol, rb_node);
430 
431 	return NULL;
432 }
433 
symbols__next(struct symbol * sym)434 static struct symbol *symbols__next(struct symbol *sym)
435 {
436 	struct rb_node *n = rb_next(&sym->rb_node);
437 
438 	if (n)
439 		return rb_entry(n, struct symbol, rb_node);
440 
441 	return NULL;
442 }
443 
symbols__sort_name_cmp(const void * vlhs,const void * vrhs)444 static int symbols__sort_name_cmp(const void *vlhs, const void *vrhs)
445 {
446 	const struct symbol *lhs = *((const struct symbol **)vlhs);
447 	const struct symbol *rhs = *((const struct symbol **)vrhs);
448 
449 	return strcmp(lhs->name, rhs->name);
450 }
451 
symbols__sort_by_name(struct rb_root_cached * source,size_t * len)452 static struct symbol **symbols__sort_by_name(struct rb_root_cached *source, size_t *len)
453 {
454 	struct rb_node *nd;
455 	struct symbol **result;
456 	size_t i = 0, size = 0;
457 
458 	for (nd = rb_first_cached(source); nd; nd = rb_next(nd))
459 		size++;
460 
461 	result = malloc(sizeof(*result) * size);
462 	if (!result)
463 		return NULL;
464 
465 	for (nd = rb_first_cached(source); nd; nd = rb_next(nd)) {
466 		struct symbol *pos = rb_entry(nd, struct symbol, rb_node);
467 
468 		result[i++] = pos;
469 	}
470 	qsort(result, size, sizeof(*result), symbols__sort_name_cmp);
471 	*len = size;
472 	return result;
473 }
474 
symbol__match_symbol_name(const char * name,const char * str,enum symbol_tag_include includes)475 int symbol__match_symbol_name(const char *name, const char *str,
476 			      enum symbol_tag_include includes)
477 {
478 	const char *versioning;
479 
480 	if (includes == SYMBOL_TAG_INCLUDE__DEFAULT_ONLY &&
481 	    (versioning = strstr(name, "@@"))) {
482 		int len = strlen(str);
483 
484 		if (len < versioning - name)
485 			len = versioning - name;
486 
487 		return arch__compare_symbol_names_n(name, str, len);
488 	} else
489 		return arch__compare_symbol_names(name, str);
490 }
491 
symbols__find_by_name(struct symbol * symbols[],size_t symbols_len,const char * name,enum symbol_tag_include includes,size_t * found_idx)492 static struct symbol *symbols__find_by_name(struct symbol *symbols[],
493 					    size_t symbols_len,
494 					    const char *name,
495 					    enum symbol_tag_include includes,
496 					    size_t *found_idx)
497 {
498 	size_t i, lower = 0, upper = symbols_len;
499 	struct symbol *s = NULL;
500 
501 	if (found_idx)
502 		*found_idx = SIZE_MAX;
503 
504 	if (!symbols_len)
505 		return NULL;
506 
507 	while (lower < upper) {
508 		int cmp;
509 
510 		i = (lower + upper) / 2;
511 		cmp = symbol__match_symbol_name(symbols[i]->name, name, includes);
512 
513 		if (cmp > 0)
514 			upper = i;
515 		else if (cmp < 0)
516 			lower = i + 1;
517 		else {
518 			if (found_idx)
519 				*found_idx = i;
520 			s = symbols[i];
521 			break;
522 		}
523 	}
524 	if (s && includes != SYMBOL_TAG_INCLUDE__DEFAULT_ONLY) {
525 		/* return first symbol that has same name (if any) */
526 		for (; i > 0; i--) {
527 			struct symbol *tmp = symbols[i - 1];
528 
529 			if (!arch__compare_symbol_names(tmp->name, s->name)) {
530 				if (found_idx)
531 					*found_idx = i - 1;
532 				s = tmp;
533 			} else
534 				break;
535 		}
536 	}
537 	assert(!found_idx || !s || s == symbols[*found_idx]);
538 	return s;
539 }
540 
dso__reset_find_symbol_cache(struct dso * dso)541 void dso__reset_find_symbol_cache(struct dso *dso)
542 {
543 	dso__set_last_find_result_addr(dso, 0);
544 	dso__set_last_find_result_symbol(dso, NULL);
545 }
546 
dso__insert_symbol(struct dso * dso,struct symbol * sym)547 void dso__insert_symbol(struct dso *dso, struct symbol *sym)
548 {
549 	__symbols__insert(dso__symbols(dso), sym, dso__kernel(dso));
550 
551 	/* update the symbol cache if necessary */
552 	if (dso__last_find_result_addr(dso) >= sym->start &&
553 	    (dso__last_find_result_addr(dso) < sym->end ||
554 	    sym->start == sym->end)) {
555 		dso__set_last_find_result_symbol(dso, sym);
556 	}
557 }
558 
dso__delete_symbol(struct dso * dso,struct symbol * sym)559 void dso__delete_symbol(struct dso *dso, struct symbol *sym)
560 {
561 	rb_erase_cached(&sym->rb_node, dso__symbols(dso));
562 	symbol__delete(sym);
563 	dso__reset_find_symbol_cache(dso);
564 }
565 
dso__find_symbol(struct dso * dso,u64 addr)566 struct symbol *dso__find_symbol(struct dso *dso, u64 addr)
567 {
568 	if (dso__last_find_result_addr(dso) != addr || dso__last_find_result_symbol(dso) == NULL) {
569 		dso__set_last_find_result_addr(dso, addr);
570 		dso__set_last_find_result_symbol(dso, symbols__find(dso__symbols(dso), addr));
571 	}
572 
573 	return dso__last_find_result_symbol(dso);
574 }
575 
dso__find_symbol_nocache(struct dso * dso,u64 addr)576 struct symbol *dso__find_symbol_nocache(struct dso *dso, u64 addr)
577 {
578 	return symbols__find(dso__symbols(dso), addr);
579 }
580 
dso__first_symbol(struct dso * dso)581 struct symbol *dso__first_symbol(struct dso *dso)
582 {
583 	return symbols__first(dso__symbols(dso));
584 }
585 
dso__last_symbol(struct dso * dso)586 struct symbol *dso__last_symbol(struct dso *dso)
587 {
588 	return symbols__last(dso__symbols(dso));
589 }
590 
dso__next_symbol(struct symbol * sym)591 struct symbol *dso__next_symbol(struct symbol *sym)
592 {
593 	return symbols__next(sym);
594 }
595 
dso__next_symbol_by_name(struct dso * dso,size_t * idx)596 struct symbol *dso__next_symbol_by_name(struct dso *dso, size_t *idx)
597 {
598 	if (*idx + 1 >= dso__symbol_names_len(dso))
599 		return NULL;
600 
601 	++*idx;
602 	return dso__symbol_names(dso)[*idx];
603 }
604 
605  /*
606   * Returns first symbol that matched with @name.
607   */
dso__find_symbol_by_name(struct dso * dso,const char * name,size_t * idx)608 struct symbol *dso__find_symbol_by_name(struct dso *dso, const char *name, size_t *idx)
609 {
610 	struct symbol *s = symbols__find_by_name(dso__symbol_names(dso),
611 						 dso__symbol_names_len(dso),
612 						 name, SYMBOL_TAG_INCLUDE__NONE, idx);
613 	if (!s) {
614 		s = symbols__find_by_name(dso__symbol_names(dso), dso__symbol_names_len(dso),
615 					  name, SYMBOL_TAG_INCLUDE__DEFAULT_ONLY, idx);
616 	}
617 	return s;
618 }
619 
dso__sort_by_name(struct dso * dso)620 void dso__sort_by_name(struct dso *dso)
621 {
622 	mutex_lock(dso__lock(dso));
623 	if (!dso__sorted_by_name(dso)) {
624 		size_t len;
625 
626 		dso__set_symbol_names(dso, symbols__sort_by_name(dso__symbols(dso), &len));
627 		if (dso__symbol_names(dso)) {
628 			dso__set_symbol_names_len(dso, len);
629 			dso__set_sorted_by_name(dso);
630 		}
631 	}
632 	mutex_unlock(dso__lock(dso));
633 }
634 
635 /*
636  * While we find nice hex chars, build a long_val.
637  * Return number of chars processed.
638  */
hex2u64(const char * ptr,u64 * long_val)639 static int hex2u64(const char *ptr, u64 *long_val)
640 {
641 	char *p;
642 
643 	*long_val = strtoull(ptr, &p, 16);
644 
645 	return p - ptr;
646 }
647 
648 
modules__parse(const char * filename,void * arg,int (* process_module)(void * arg,const char * name,u64 start,u64 size))649 int modules__parse(const char *filename, void *arg,
650 		   int (*process_module)(void *arg, const char *name,
651 					 u64 start, u64 size))
652 {
653 	char *line = NULL;
654 	size_t n;
655 	FILE *file;
656 	int err = 0;
657 
658 	file = fopen(filename, "r");
659 	if (file == NULL)
660 		return -1;
661 
662 	while (1) {
663 		char name[PATH_MAX];
664 		u64 start, size;
665 		char *sep, *endptr;
666 		ssize_t line_len;
667 
668 		line_len = getline(&line, &n, file);
669 		if (line_len < 0) {
670 			if (feof(file))
671 				break;
672 			err = -1;
673 			goto out;
674 		}
675 
676 		if (!line) {
677 			err = -1;
678 			goto out;
679 		}
680 
681 		line[--line_len] = '\0'; /* \n */
682 
683 		sep = strrchr(line, 'x');
684 		if (sep == NULL)
685 			continue;
686 
687 		hex2u64(sep + 1, &start);
688 
689 		sep = strchr(line, ' ');
690 		if (sep == NULL)
691 			continue;
692 
693 		*sep = '\0';
694 
695 		scnprintf(name, sizeof(name), "[%s]", line);
696 
697 		size = strtoul(sep + 1, &endptr, 0);
698 		if (*endptr != ' ' && *endptr != '\t')
699 			continue;
700 
701 		err = process_module(arg, name, start, size);
702 		if (err)
703 			break;
704 	}
705 out:
706 	free(line);
707 	fclose(file);
708 	return err;
709 }
710 
711 /*
712  * These are symbols in the kernel image, so make sure that
713  * sym is from a kernel DSO.
714  */
symbol__is_idle(const char * name)715 static bool symbol__is_idle(const char *name)
716 {
717 	const char * const idle_symbols[] = {
718 		"acpi_idle_do_entry",
719 		"acpi_processor_ffh_cstate_enter",
720 		"arch_cpu_idle",
721 		"cpu_idle",
722 		"cpu_startup_entry",
723 		"idle_cpu",
724 		"intel_idle",
725 		"intel_idle_ibrs",
726 		"default_idle",
727 		"native_safe_halt",
728 		"enter_idle",
729 		"exit_idle",
730 		"mwait_idle",
731 		"mwait_idle_with_hints",
732 		"mwait_idle_with_hints.constprop.0",
733 		"poll_idle",
734 		"ppc64_runlatch_off",
735 		"pseries_dedicated_idle_sleep",
736 		"psw_idle",
737 		"psw_idle_exit",
738 		NULL
739 	};
740 	int i;
741 	static struct strlist *idle_symbols_list;
742 
743 	if (idle_symbols_list)
744 		return strlist__has_entry(idle_symbols_list, name);
745 
746 	idle_symbols_list = strlist__new(NULL, NULL);
747 
748 	for (i = 0; idle_symbols[i]; i++)
749 		strlist__add(idle_symbols_list, idle_symbols[i]);
750 
751 	return strlist__has_entry(idle_symbols_list, name);
752 }
753 
map__process_kallsym_symbol(void * arg,const char * name,char type,u64 start)754 static int map__process_kallsym_symbol(void *arg, const char *name,
755 				       char type, u64 start)
756 {
757 	struct symbol *sym;
758 	struct dso *dso = arg;
759 	struct rb_root_cached *root = dso__symbols(dso);
760 
761 	if (!symbol_type__filter(type))
762 		return 0;
763 
764 	/* Ignore local symbols for ARM modules */
765 	if (name[0] == '$')
766 		return 0;
767 
768 	/*
769 	 * module symbols are not sorted so we add all
770 	 * symbols, setting length to 0, and rely on
771 	 * symbols__fixup_end() to fix it up.
772 	 */
773 	sym = symbol__new(start, 0, kallsyms2elf_binding(type), kallsyms2elf_type(type), name);
774 	if (sym == NULL)
775 		return -ENOMEM;
776 	/*
777 	 * We will pass the symbols to the filter later, in
778 	 * map__split_kallsyms, when we have split the maps per module
779 	 */
780 	__symbols__insert(root, sym, !strchr(name, '['));
781 
782 	return 0;
783 }
784 
785 /*
786  * Loads the function entries in /proc/kallsyms into kernel_map->dso,
787  * so that we can in the next step set the symbol ->end address and then
788  * call kernel_maps__split_kallsyms.
789  */
dso__load_all_kallsyms(struct dso * dso,const char * filename)790 static int dso__load_all_kallsyms(struct dso *dso, const char *filename)
791 {
792 	return kallsyms__parse(filename, dso, map__process_kallsym_symbol);
793 }
794 
maps__split_kallsyms_for_kcore(struct maps * kmaps,struct dso * dso)795 static int maps__split_kallsyms_for_kcore(struct maps *kmaps, struct dso *dso)
796 {
797 	struct symbol *pos;
798 	int count = 0;
799 	struct rb_root_cached *root = dso__symbols(dso);
800 	struct rb_root_cached old_root = *root;
801 	struct rb_node *next = rb_first_cached(root);
802 
803 	if (!kmaps)
804 		return -1;
805 
806 	*root = RB_ROOT_CACHED;
807 
808 	while (next) {
809 		struct map *curr_map;
810 		struct dso *curr_map_dso;
811 		char *module;
812 
813 		pos = rb_entry(next, struct symbol, rb_node);
814 		next = rb_next(&pos->rb_node);
815 
816 		rb_erase_cached(&pos->rb_node, &old_root);
817 		RB_CLEAR_NODE(&pos->rb_node);
818 		module = strchr(pos->name, '\t');
819 		if (module)
820 			*module = '\0';
821 
822 		curr_map = maps__find(kmaps, pos->start);
823 
824 		if (!curr_map) {
825 			symbol__delete(pos);
826 			continue;
827 		}
828 		curr_map_dso = map__dso(curr_map);
829 		pos->start -= map__start(curr_map) - map__pgoff(curr_map);
830 		if (pos->end > map__end(curr_map))
831 			pos->end = map__end(curr_map);
832 		if (pos->end)
833 			pos->end -= map__start(curr_map) - map__pgoff(curr_map);
834 		symbols__insert(dso__symbols(curr_map_dso), pos);
835 		++count;
836 		map__put(curr_map);
837 	}
838 
839 	/* Symbols have been adjusted */
840 	dso__set_adjust_symbols(dso, true);
841 
842 	return count;
843 }
844 
845 /*
846  * Split the symbols into maps, making sure there are no overlaps, i.e. the
847  * kernel range is broken in several maps, named [kernel].N, as we don't have
848  * the original ELF section names vmlinux have.
849  */
maps__split_kallsyms(struct maps * kmaps,struct dso * dso,u64 delta,struct map * initial_map)850 static int maps__split_kallsyms(struct maps *kmaps, struct dso *dso, u64 delta,
851 				struct map *initial_map)
852 {
853 	struct machine *machine;
854 	struct map *curr_map = map__get(initial_map);
855 	struct symbol *pos;
856 	int count = 0, moved = 0;
857 	struct rb_root_cached *root = dso__symbols(dso);
858 	struct rb_node *next = rb_first_cached(root);
859 	int kernel_range = 0;
860 	bool x86_64;
861 
862 	if (!kmaps)
863 		return -1;
864 
865 	machine = maps__machine(kmaps);
866 
867 	x86_64 = machine__is(machine, "x86_64");
868 
869 	while (next) {
870 		char *module;
871 
872 		pos = rb_entry(next, struct symbol, rb_node);
873 		next = rb_next(&pos->rb_node);
874 
875 		module = strchr(pos->name, '\t');
876 		if (module) {
877 			struct dso *curr_map_dso;
878 
879 			if (!symbol_conf.use_modules)
880 				goto discard_symbol;
881 
882 			*module++ = '\0';
883 			curr_map_dso = map__dso(curr_map);
884 			if (strcmp(dso__short_name(curr_map_dso), module)) {
885 				if (!RC_CHK_EQUAL(curr_map, initial_map) &&
886 				    dso__kernel(dso) == DSO_SPACE__KERNEL_GUEST &&
887 				    machine__is_default_guest(machine)) {
888 					/*
889 					 * We assume all symbols of a module are
890 					 * continuous in * kallsyms, so curr_map
891 					 * points to a module and all its
892 					 * symbols are in its kmap. Mark it as
893 					 * loaded.
894 					 */
895 					dso__set_loaded(curr_map_dso);
896 				}
897 
898 				map__zput(curr_map);
899 				curr_map = maps__find_by_name(kmaps, module);
900 				if (curr_map == NULL) {
901 					pr_debug("%s/proc/{kallsyms,modules} "
902 					         "inconsistency while looking "
903 						 "for \"%s\" module!\n",
904 						 machine->root_dir, module);
905 					curr_map = map__get(initial_map);
906 					goto discard_symbol;
907 				}
908 				curr_map_dso = map__dso(curr_map);
909 				if (dso__loaded(curr_map_dso) &&
910 				    !machine__is_default_guest(machine))
911 					goto discard_symbol;
912 			}
913 			/*
914 			 * So that we look just like we get from .ko files,
915 			 * i.e. not prelinked, relative to initial_map->start.
916 			 */
917 			pos->start = map__map_ip(curr_map, pos->start);
918 			pos->end   = map__map_ip(curr_map, pos->end);
919 		} else if (x86_64 && is_entry_trampoline(pos->name)) {
920 			/*
921 			 * These symbols are not needed anymore since the
922 			 * trampoline maps refer to the text section and it's
923 			 * symbols instead. Avoid having to deal with
924 			 * relocations, and the assumption that the first symbol
925 			 * is the start of kernel text, by simply removing the
926 			 * symbols at this point.
927 			 */
928 			goto discard_symbol;
929 		} else if (!RC_CHK_EQUAL(curr_map, initial_map)) {
930 			char dso_name[PATH_MAX];
931 			struct dso *ndso;
932 
933 			if (delta) {
934 				/* Kernel was relocated at boot time */
935 				pos->start -= delta;
936 				pos->end -= delta;
937 			}
938 
939 			if (count == 0) {
940 				map__zput(curr_map);
941 				curr_map = map__get(initial_map);
942 				goto add_symbol;
943 			}
944 
945 			if (dso__kernel(dso) == DSO_SPACE__KERNEL_GUEST)
946 				snprintf(dso_name, sizeof(dso_name),
947 					"[guest.kernel].%d",
948 					kernel_range++);
949 			else
950 				snprintf(dso_name, sizeof(dso_name),
951 					"[kernel].%d",
952 					kernel_range++);
953 
954 			ndso = dso__new(dso_name);
955 			map__zput(curr_map);
956 			if (ndso == NULL)
957 				return -1;
958 
959 			dso__set_kernel(ndso, dso__kernel(dso));
960 
961 			curr_map = map__new2(pos->start, ndso);
962 			if (curr_map == NULL) {
963 				dso__put(ndso);
964 				return -1;
965 			}
966 
967 			map__set_mapping_type(curr_map, MAPPING_TYPE__IDENTITY);
968 			if (maps__insert(kmaps, curr_map)) {
969 				map__zput(curr_map);
970 				dso__put(ndso);
971 				return -1;
972 			}
973 			++kernel_range;
974 		} else if (delta) {
975 			/* Kernel was relocated at boot time */
976 			pos->start -= delta;
977 			pos->end -= delta;
978 		}
979 add_symbol:
980 		if (!RC_CHK_EQUAL(curr_map, initial_map)) {
981 			struct dso *curr_map_dso = map__dso(curr_map);
982 
983 			rb_erase_cached(&pos->rb_node, root);
984 			symbols__insert(dso__symbols(curr_map_dso), pos);
985 			++moved;
986 		} else
987 			++count;
988 
989 		continue;
990 discard_symbol:
991 		rb_erase_cached(&pos->rb_node, root);
992 		symbol__delete(pos);
993 	}
994 
995 	if (!RC_CHK_EQUAL(curr_map, initial_map) &&
996 	    dso__kernel(dso) == DSO_SPACE__KERNEL_GUEST &&
997 	    machine__is_default_guest(maps__machine(kmaps))) {
998 		dso__set_loaded(map__dso(curr_map));
999 	}
1000 	map__put(curr_map);
1001 	return count + moved;
1002 }
1003 
symbol__restricted_filename(const char * filename,const char * restricted_filename)1004 bool symbol__restricted_filename(const char *filename,
1005 				 const char *restricted_filename)
1006 {
1007 	bool restricted = false;
1008 
1009 	if (symbol_conf.kptr_restrict) {
1010 		char *r = realpath(filename, NULL);
1011 
1012 		if (r != NULL) {
1013 			restricted = strcmp(r, restricted_filename) == 0;
1014 			free(r);
1015 			return restricted;
1016 		}
1017 	}
1018 
1019 	return restricted;
1020 }
1021 
1022 struct module_info {
1023 	struct rb_node rb_node;
1024 	char *name;
1025 	u64 start;
1026 };
1027 
add_module(struct module_info * mi,struct rb_root * modules)1028 static void add_module(struct module_info *mi, struct rb_root *modules)
1029 {
1030 	struct rb_node **p = &modules->rb_node;
1031 	struct rb_node *parent = NULL;
1032 	struct module_info *m;
1033 
1034 	while (*p != NULL) {
1035 		parent = *p;
1036 		m = rb_entry(parent, struct module_info, rb_node);
1037 		if (strcmp(mi->name, m->name) < 0)
1038 			p = &(*p)->rb_left;
1039 		else
1040 			p = &(*p)->rb_right;
1041 	}
1042 	rb_link_node(&mi->rb_node, parent, p);
1043 	rb_insert_color(&mi->rb_node, modules);
1044 }
1045 
delete_modules(struct rb_root * modules)1046 static void delete_modules(struct rb_root *modules)
1047 {
1048 	struct module_info *mi;
1049 	struct rb_node *next = rb_first(modules);
1050 
1051 	while (next) {
1052 		mi = rb_entry(next, struct module_info, rb_node);
1053 		next = rb_next(&mi->rb_node);
1054 		rb_erase(&mi->rb_node, modules);
1055 		zfree(&mi->name);
1056 		free(mi);
1057 	}
1058 }
1059 
find_module(const char * name,struct rb_root * modules)1060 static struct module_info *find_module(const char *name,
1061 				       struct rb_root *modules)
1062 {
1063 	struct rb_node *n = modules->rb_node;
1064 
1065 	while (n) {
1066 		struct module_info *m;
1067 		int cmp;
1068 
1069 		m = rb_entry(n, struct module_info, rb_node);
1070 		cmp = strcmp(name, m->name);
1071 		if (cmp < 0)
1072 			n = n->rb_left;
1073 		else if (cmp > 0)
1074 			n = n->rb_right;
1075 		else
1076 			return m;
1077 	}
1078 
1079 	return NULL;
1080 }
1081 
__read_proc_modules(void * arg,const char * name,u64 start,u64 size __maybe_unused)1082 static int __read_proc_modules(void *arg, const char *name, u64 start,
1083 			       u64 size __maybe_unused)
1084 {
1085 	struct rb_root *modules = arg;
1086 	struct module_info *mi;
1087 
1088 	mi = zalloc(sizeof(struct module_info));
1089 	if (!mi)
1090 		return -ENOMEM;
1091 
1092 	mi->name = strdup(name);
1093 	mi->start = start;
1094 
1095 	if (!mi->name) {
1096 		free(mi);
1097 		return -ENOMEM;
1098 	}
1099 
1100 	add_module(mi, modules);
1101 
1102 	return 0;
1103 }
1104 
read_proc_modules(const char * filename,struct rb_root * modules)1105 static int read_proc_modules(const char *filename, struct rb_root *modules)
1106 {
1107 	if (symbol__restricted_filename(filename, "/proc/modules"))
1108 		return -1;
1109 
1110 	if (modules__parse(filename, modules, __read_proc_modules)) {
1111 		delete_modules(modules);
1112 		return -1;
1113 	}
1114 
1115 	return 0;
1116 }
1117 
compare_proc_modules(const char * from,const char * to)1118 int compare_proc_modules(const char *from, const char *to)
1119 {
1120 	struct rb_root from_modules = RB_ROOT;
1121 	struct rb_root to_modules = RB_ROOT;
1122 	struct rb_node *from_node, *to_node;
1123 	struct module_info *from_m, *to_m;
1124 	int ret = -1;
1125 
1126 	if (read_proc_modules(from, &from_modules))
1127 		return -1;
1128 
1129 	if (read_proc_modules(to, &to_modules))
1130 		goto out_delete_from;
1131 
1132 	from_node = rb_first(&from_modules);
1133 	to_node = rb_first(&to_modules);
1134 	while (from_node) {
1135 		if (!to_node)
1136 			break;
1137 
1138 		from_m = rb_entry(from_node, struct module_info, rb_node);
1139 		to_m = rb_entry(to_node, struct module_info, rb_node);
1140 
1141 		if (from_m->start != to_m->start ||
1142 		    strcmp(from_m->name, to_m->name))
1143 			break;
1144 
1145 		from_node = rb_next(from_node);
1146 		to_node = rb_next(to_node);
1147 	}
1148 
1149 	if (!from_node && !to_node)
1150 		ret = 0;
1151 
1152 	delete_modules(&to_modules);
1153 out_delete_from:
1154 	delete_modules(&from_modules);
1155 
1156 	return ret;
1157 }
1158 
do_validate_kcore_modules_cb(struct map * old_map,void * data)1159 static int do_validate_kcore_modules_cb(struct map *old_map, void *data)
1160 {
1161 	struct rb_root *modules = data;
1162 	struct module_info *mi;
1163 	struct dso *dso;
1164 
1165 	if (!__map__is_kmodule(old_map))
1166 		return 0;
1167 
1168 	dso = map__dso(old_map);
1169 	/* Module must be in memory at the same address */
1170 	mi = find_module(dso__short_name(dso), modules);
1171 	if (!mi || mi->start != map__start(old_map))
1172 		return -EINVAL;
1173 
1174 	return 0;
1175 }
1176 
do_validate_kcore_modules(const char * filename,struct maps * kmaps)1177 static int do_validate_kcore_modules(const char *filename, struct maps *kmaps)
1178 {
1179 	struct rb_root modules = RB_ROOT;
1180 	int err;
1181 
1182 	err = read_proc_modules(filename, &modules);
1183 	if (err)
1184 		return err;
1185 
1186 	err = maps__for_each_map(kmaps, do_validate_kcore_modules_cb, &modules);
1187 
1188 	delete_modules(&modules);
1189 	return err;
1190 }
1191 
1192 /*
1193  * If kallsyms is referenced by name then we look for filename in the same
1194  * directory.
1195  */
filename_from_kallsyms_filename(char * filename,const char * base_name,const char * kallsyms_filename)1196 static bool filename_from_kallsyms_filename(char *filename,
1197 					    const char *base_name,
1198 					    const char *kallsyms_filename)
1199 {
1200 	char *name;
1201 
1202 	strcpy(filename, kallsyms_filename);
1203 	name = strrchr(filename, '/');
1204 	if (!name)
1205 		return false;
1206 
1207 	name += 1;
1208 
1209 	if (!strcmp(name, "kallsyms")) {
1210 		strcpy(name, base_name);
1211 		return true;
1212 	}
1213 
1214 	return false;
1215 }
1216 
validate_kcore_modules(const char * kallsyms_filename,struct map * map)1217 static int validate_kcore_modules(const char *kallsyms_filename,
1218 				  struct map *map)
1219 {
1220 	struct maps *kmaps = map__kmaps(map);
1221 	char modules_filename[PATH_MAX];
1222 
1223 	if (!kmaps)
1224 		return -EINVAL;
1225 
1226 	if (!filename_from_kallsyms_filename(modules_filename, "modules",
1227 					     kallsyms_filename))
1228 		return -EINVAL;
1229 
1230 	if (do_validate_kcore_modules(modules_filename, kmaps))
1231 		return -EINVAL;
1232 
1233 	return 0;
1234 }
1235 
validate_kcore_addresses(const char * kallsyms_filename,struct map * map)1236 static int validate_kcore_addresses(const char *kallsyms_filename,
1237 				    struct map *map)
1238 {
1239 	struct kmap *kmap = map__kmap(map);
1240 
1241 	if (!kmap)
1242 		return -EINVAL;
1243 
1244 	if (kmap->ref_reloc_sym && kmap->ref_reloc_sym->name) {
1245 		u64 start;
1246 
1247 		if (kallsyms__get_function_start(kallsyms_filename,
1248 						 kmap->ref_reloc_sym->name, &start))
1249 			return -ENOENT;
1250 		if (start != kmap->ref_reloc_sym->addr)
1251 			return -EINVAL;
1252 	}
1253 
1254 	return validate_kcore_modules(kallsyms_filename, map);
1255 }
1256 
1257 struct kcore_mapfn_data {
1258 	struct dso *dso;
1259 	struct list_head maps;
1260 };
1261 
kcore_mapfn(u64 start,u64 len,u64 pgoff,void * data)1262 static int kcore_mapfn(u64 start, u64 len, u64 pgoff, void *data)
1263 {
1264 	struct kcore_mapfn_data *md = data;
1265 	struct map_list_node *list_node = map_list_node__new();
1266 
1267 	if (!list_node)
1268 		return -ENOMEM;
1269 
1270 	list_node->map = map__new2(start, md->dso);
1271 	if (!list_node->map) {
1272 		free(list_node);
1273 		return -ENOMEM;
1274 	}
1275 
1276 	map__set_end(list_node->map, map__start(list_node->map) + len);
1277 	map__set_pgoff(list_node->map, pgoff);
1278 
1279 	list_add(&list_node->node, &md->maps);
1280 
1281 	return 0;
1282 }
1283 
remove_old_maps(struct map * map,void * data)1284 static bool remove_old_maps(struct map *map, void *data)
1285 {
1286 	const struct map *map_to_save = data;
1287 
1288 	/*
1289 	 * We need to preserve eBPF maps even if they are covered by kcore,
1290 	 * because we need to access eBPF dso for source data.
1291 	 */
1292 	return !RC_CHK_EQUAL(map, map_to_save) && !__map__is_bpf_prog(map);
1293 }
1294 
dso__load_kcore(struct dso * dso,struct map * map,const char * kallsyms_filename)1295 static 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 *map_ref, *replacement_map = NULL;
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 = maps__machine(kmaps);
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(map) & PROT_EXEC, kcore_mapfn, &md,
1336 			      &is_64_bit);
1337 	if (err)
1338 		goto out_err;
1339 	dso__set_is_64_bit(dso, 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__remove_maps(kmaps, remove_old_maps, map);
1348 	machine->trampolines_mapped = false;
1349 
1350 	/* Find the kernel map using the '_stext' symbol */
1351 	if (!kallsyms__get_function_start(kallsyms_filename, "_stext", &stext)) {
1352 		u64 replacement_size = 0;
1353 		struct map_list_node *new_node;
1354 
1355 		list_for_each_entry(new_node, &md.maps, node) {
1356 			struct map *new_map = new_node->map;
1357 			u64 new_size = map__size(new_map);
1358 
1359 			if (!(stext >= map__start(new_map) && stext < map__end(new_map)))
1360 				continue;
1361 
1362 			/*
1363 			 * On some architectures, ARM64 for example, the kernel
1364 			 * text can get allocated inside of the vmalloc segment.
1365 			 * Select the smallest matching segment, in case stext
1366 			 * falls within more than one in the list.
1367 			 */
1368 			if (!replacement_map || new_size < replacement_size) {
1369 				replacement_map = new_map;
1370 				replacement_size = new_size;
1371 			}
1372 		}
1373 	}
1374 
1375 	if (!replacement_map)
1376 		replacement_map = list_entry(md.maps.next, struct map_list_node, node)->map;
1377 
1378 	/*
1379 	 * Update addresses of vmlinux map. Re-insert it to ensure maps are
1380 	 * correctly ordered. Do this before using maps__merge_in() for the
1381 	 * remaining maps so vmlinux gets split if necessary.
1382 	 */
1383 	map_ref = map__get(map);
1384 	maps__remove(kmaps, map_ref);
1385 
1386 	map__set_start(map_ref, map__start(replacement_map));
1387 	map__set_end(map_ref, map__end(replacement_map));
1388 	map__set_pgoff(map_ref, map__pgoff(replacement_map));
1389 	map__set_mapping_type(map_ref, map__mapping_type(replacement_map));
1390 
1391 	err = maps__insert(kmaps, map_ref);
1392 	map__put(map_ref);
1393 	if (err)
1394 		goto out_err;
1395 
1396 	/* Add new maps */
1397 	while (!list_empty(&md.maps)) {
1398 		struct map_list_node *new_node = list_entry(md.maps.next, struct map_list_node, node);
1399 		struct map *new_map = new_node->map;
1400 
1401 		list_del_init(&new_node->node);
1402 
1403 		/* skip if replacement_map, already inserted above */
1404 		if (!RC_CHK_EQUAL(new_map, replacement_map)) {
1405 			/*
1406 			 * Merge kcore map into existing maps,
1407 			 * and ensure that current maps (eBPF)
1408 			 * stay intact.
1409 			 */
1410 			if (maps__merge_in(kmaps, new_map)) {
1411 				err = -EINVAL;
1412 				goto out_err;
1413 			}
1414 		}
1415 		free(new_node);
1416 	}
1417 
1418 	if (machine__is(machine, "x86_64")) {
1419 		u64 addr;
1420 
1421 		/*
1422 		 * If one of the corresponding symbols is there, assume the
1423 		 * entry trampoline maps are too.
1424 		 */
1425 		if (!kallsyms__get_function_start(kallsyms_filename,
1426 						  ENTRY_TRAMPOLINE_NAME,
1427 						  &addr))
1428 			machine->trampolines_mapped = true;
1429 	}
1430 
1431 	/*
1432 	 * Set the data type and long name so that kcore can be read via
1433 	 * dso__data_read_addr().
1434 	 */
1435 	if (dso__kernel(dso) == DSO_SPACE__KERNEL_GUEST)
1436 		dso__set_binary_type(dso, DSO_BINARY_TYPE__GUEST_KCORE);
1437 	else
1438 		dso__set_binary_type(dso, DSO_BINARY_TYPE__KCORE);
1439 	dso__set_long_name(dso, strdup(kcore_filename), true);
1440 
1441 	close(fd);
1442 
1443 	if (map__prot(map) & PROT_EXEC)
1444 		pr_debug("Using %s for kernel object code\n", kcore_filename);
1445 	else
1446 		pr_debug("Using %s for kernel data\n", kcore_filename);
1447 
1448 	return 0;
1449 
1450 out_err:
1451 	while (!list_empty(&md.maps)) {
1452 		struct map_list_node *list_node;
1453 
1454 		list_node = list_entry(md.maps.next, struct map_list_node, node);
1455 		list_del_init(&list_node->node);
1456 		map__zput(list_node->map);
1457 		free(list_node);
1458 	}
1459 	close(fd);
1460 	return err;
1461 }
1462 
1463 /*
1464  * If the kernel is relocated at boot time, kallsyms won't match.  Compute the
1465  * delta based on the relocation reference symbol.
1466  */
kallsyms__delta(struct kmap * kmap,const char * filename,u64 * delta)1467 static int kallsyms__delta(struct kmap *kmap, const char *filename, u64 *delta)
1468 {
1469 	u64 addr;
1470 
1471 	if (!kmap->ref_reloc_sym || !kmap->ref_reloc_sym->name)
1472 		return 0;
1473 
1474 	if (kallsyms__get_function_start(filename, kmap->ref_reloc_sym->name, &addr))
1475 		return -1;
1476 
1477 	*delta = addr - kmap->ref_reloc_sym->addr;
1478 	return 0;
1479 }
1480 
__dso__load_kallsyms(struct dso * dso,const char * filename,struct map * map,bool no_kcore)1481 int __dso__load_kallsyms(struct dso *dso, const char *filename,
1482 			 struct map *map, bool no_kcore)
1483 {
1484 	struct kmap *kmap = map__kmap(map);
1485 	u64 delta = 0;
1486 
1487 	if (symbol__restricted_filename(filename, "/proc/kallsyms"))
1488 		return -1;
1489 
1490 	if (!kmap || !kmap->kmaps)
1491 		return -1;
1492 
1493 	if (dso__load_all_kallsyms(dso, filename) < 0)
1494 		return -1;
1495 
1496 	if (kallsyms__delta(kmap, filename, &delta))
1497 		return -1;
1498 
1499 	symbols__fixup_end(dso__symbols(dso), true);
1500 	symbols__fixup_duplicate(dso__symbols(dso));
1501 
1502 	if (dso__kernel(dso) == DSO_SPACE__KERNEL_GUEST)
1503 		dso__set_symtab_type(dso, DSO_BINARY_TYPE__GUEST_KALLSYMS);
1504 	else
1505 		dso__set_symtab_type(dso, DSO_BINARY_TYPE__KALLSYMS);
1506 
1507 	if (!no_kcore && !dso__load_kcore(dso, map, filename))
1508 		return maps__split_kallsyms_for_kcore(kmap->kmaps, dso);
1509 	else
1510 		return maps__split_kallsyms(kmap->kmaps, dso, delta, map);
1511 }
1512 
dso__load_kallsyms(struct dso * dso,const char * filename,struct map * map)1513 int dso__load_kallsyms(struct dso *dso, const char *filename,
1514 		       struct map *map)
1515 {
1516 	return __dso__load_kallsyms(dso, filename, map, false);
1517 }
1518 
dso__load_perf_map(const char * map_path,struct dso * dso)1519 static int dso__load_perf_map(const char *map_path, struct dso *dso)
1520 {
1521 	char *line = NULL;
1522 	size_t n;
1523 	FILE *file;
1524 	int nr_syms = 0;
1525 
1526 	file = fopen(map_path, "r");
1527 	if (file == NULL)
1528 		goto out_failure;
1529 
1530 	while (!feof(file)) {
1531 		u64 start, size;
1532 		struct symbol *sym;
1533 		int line_len, len;
1534 
1535 		line_len = getline(&line, &n, file);
1536 		if (line_len < 0)
1537 			break;
1538 
1539 		if (!line)
1540 			goto out_failure;
1541 
1542 		line[--line_len] = '\0'; /* \n */
1543 
1544 		len = hex2u64(line, &start);
1545 
1546 		len++;
1547 		if (len + 2 >= line_len)
1548 			continue;
1549 
1550 		len += hex2u64(line + len, &size);
1551 
1552 		len++;
1553 		if (len + 2 >= line_len)
1554 			continue;
1555 
1556 		sym = symbol__new(start, size, STB_GLOBAL, STT_FUNC, line + len);
1557 
1558 		if (sym == NULL)
1559 			goto out_delete_line;
1560 
1561 		symbols__insert(dso__symbols(dso), sym);
1562 		nr_syms++;
1563 	}
1564 
1565 	free(line);
1566 	fclose(file);
1567 
1568 	return nr_syms;
1569 
1570 out_delete_line:
1571 	free(line);
1572 out_failure:
1573 	return -1;
1574 }
1575 
1576 #ifdef HAVE_LIBBFD_SUPPORT
1577 #define PACKAGE 'perf'
1578 #include <bfd.h>
1579 
bfd_symbols__cmpvalue(const void * a,const void * b)1580 static int bfd_symbols__cmpvalue(const void *a, const void *b)
1581 {
1582 	const asymbol *as = *(const asymbol **)a, *bs = *(const asymbol **)b;
1583 
1584 	if (bfd_asymbol_value(as) != bfd_asymbol_value(bs))
1585 		return bfd_asymbol_value(as) - bfd_asymbol_value(bs);
1586 
1587 	return bfd_asymbol_name(as)[0] - bfd_asymbol_name(bs)[0];
1588 }
1589 
bfd2elf_binding(asymbol * symbol)1590 static int bfd2elf_binding(asymbol *symbol)
1591 {
1592 	if (symbol->flags & BSF_WEAK)
1593 		return STB_WEAK;
1594 	if (symbol->flags & BSF_GLOBAL)
1595 		return STB_GLOBAL;
1596 	if (symbol->flags & BSF_LOCAL)
1597 		return STB_LOCAL;
1598 	return -1;
1599 }
1600 
dso__load_bfd_symbols(struct dso * dso,const char * debugfile)1601 int dso__load_bfd_symbols(struct dso *dso, const char *debugfile)
1602 {
1603 	int err = -1;
1604 	long symbols_size, symbols_count, i;
1605 	asection *section;
1606 	asymbol **symbols, *sym;
1607 	struct symbol *symbol;
1608 	bfd *abfd;
1609 	u64 start, len;
1610 
1611 	abfd = bfd_openr(debugfile, NULL);
1612 	if (!abfd)
1613 		return -1;
1614 
1615 	if (!bfd_check_format(abfd, bfd_object)) {
1616 		pr_debug2("%s: cannot read %s bfd file.\n", __func__,
1617 			  dso__long_name(dso));
1618 		goto out_close;
1619 	}
1620 
1621 	if (bfd_get_flavour(abfd) == bfd_target_elf_flavour)
1622 		goto out_close;
1623 
1624 	symbols_size = bfd_get_symtab_upper_bound(abfd);
1625 	if (symbols_size == 0) {
1626 		bfd_close(abfd);
1627 		return 0;
1628 	}
1629 
1630 	if (symbols_size < 0)
1631 		goto out_close;
1632 
1633 	symbols = malloc(symbols_size);
1634 	if (!symbols)
1635 		goto out_close;
1636 
1637 	symbols_count = bfd_canonicalize_symtab(abfd, symbols);
1638 	if (symbols_count < 0)
1639 		goto out_free;
1640 
1641 	section = bfd_get_section_by_name(abfd, ".text");
1642 	if (section) {
1643 		for (i = 0; i < symbols_count; ++i) {
1644 			if (!strcmp(bfd_asymbol_name(symbols[i]), "__ImageBase") ||
1645 			    !strcmp(bfd_asymbol_name(symbols[i]), "__image_base__"))
1646 				break;
1647 		}
1648 		if (i < symbols_count) {
1649 			/* PE symbols can only have 4 bytes, so use .text high bits */
1650 			u64 text_offset = (section->vma - (u32)section->vma)
1651 				+ (u32)bfd_asymbol_value(symbols[i]);
1652 			dso__set_text_offset(dso, text_offset);
1653 			dso__set_text_end(dso, (section->vma - text_offset) + section->size);
1654 		} else {
1655 			dso__set_text_offset(dso, section->vma - section->filepos);
1656 			dso__set_text_end(dso, section->filepos + section->size);
1657 		}
1658 	}
1659 
1660 	qsort(symbols, symbols_count, sizeof(asymbol *), bfd_symbols__cmpvalue);
1661 
1662 #ifdef bfd_get_section
1663 #define bfd_asymbol_section bfd_get_section
1664 #endif
1665 	for (i = 0; i < symbols_count; ++i) {
1666 		sym = symbols[i];
1667 		section = bfd_asymbol_section(sym);
1668 		if (bfd2elf_binding(sym) < 0)
1669 			continue;
1670 
1671 		while (i + 1 < symbols_count &&
1672 		       bfd_asymbol_section(symbols[i + 1]) == section &&
1673 		       bfd2elf_binding(symbols[i + 1]) < 0)
1674 			i++;
1675 
1676 		if (i + 1 < symbols_count &&
1677 		    bfd_asymbol_section(symbols[i + 1]) == section)
1678 			len = symbols[i + 1]->value - sym->value;
1679 		else
1680 			len = section->size - sym->value;
1681 
1682 		start = bfd_asymbol_value(sym) - dso__text_offset(dso);
1683 		symbol = symbol__new(start, len, bfd2elf_binding(sym), STT_FUNC,
1684 				     bfd_asymbol_name(sym));
1685 		if (!symbol)
1686 			goto out_free;
1687 
1688 		symbols__insert(dso__symbols(dso), symbol);
1689 	}
1690 #ifdef bfd_get_section
1691 #undef bfd_asymbol_section
1692 #endif
1693 
1694 	symbols__fixup_end(dso__symbols(dso), false);
1695 	symbols__fixup_duplicate(dso__symbols(dso));
1696 	dso__set_adjust_symbols(dso, true);
1697 
1698 	err = 0;
1699 out_free:
1700 	free(symbols);
1701 out_close:
1702 	bfd_close(abfd);
1703 	return err;
1704 }
1705 #endif
1706 
dso__is_compatible_symtab_type(struct dso * dso,bool kmod,enum dso_binary_type type)1707 static bool dso__is_compatible_symtab_type(struct dso *dso, bool kmod,
1708 					   enum dso_binary_type type)
1709 {
1710 	switch (type) {
1711 	case DSO_BINARY_TYPE__JAVA_JIT:
1712 	case DSO_BINARY_TYPE__DEBUGLINK:
1713 	case DSO_BINARY_TYPE__SYSTEM_PATH_DSO:
1714 	case DSO_BINARY_TYPE__FEDORA_DEBUGINFO:
1715 	case DSO_BINARY_TYPE__UBUNTU_DEBUGINFO:
1716 	case DSO_BINARY_TYPE__MIXEDUP_UBUNTU_DEBUGINFO:
1717 	case DSO_BINARY_TYPE__BUILDID_DEBUGINFO:
1718 	case DSO_BINARY_TYPE__OPENEMBEDDED_DEBUGINFO:
1719 		return !kmod && dso__kernel(dso) == DSO_SPACE__USER;
1720 
1721 	case DSO_BINARY_TYPE__KALLSYMS:
1722 	case DSO_BINARY_TYPE__VMLINUX:
1723 	case DSO_BINARY_TYPE__KCORE:
1724 		return dso__kernel(dso) == DSO_SPACE__KERNEL;
1725 
1726 	case DSO_BINARY_TYPE__GUEST_KALLSYMS:
1727 	case DSO_BINARY_TYPE__GUEST_VMLINUX:
1728 	case DSO_BINARY_TYPE__GUEST_KCORE:
1729 		return dso__kernel(dso) == DSO_SPACE__KERNEL_GUEST;
1730 
1731 	case DSO_BINARY_TYPE__GUEST_KMODULE:
1732 	case DSO_BINARY_TYPE__GUEST_KMODULE_COMP:
1733 	case DSO_BINARY_TYPE__SYSTEM_PATH_KMODULE:
1734 	case DSO_BINARY_TYPE__SYSTEM_PATH_KMODULE_COMP:
1735 		/*
1736 		 * kernel modules know their symtab type - it's set when
1737 		 * creating a module dso in machine__addnew_module_map().
1738 		 */
1739 		return kmod && dso__symtab_type(dso) == type;
1740 
1741 	case DSO_BINARY_TYPE__BUILD_ID_CACHE:
1742 	case DSO_BINARY_TYPE__BUILD_ID_CACHE_DEBUGINFO:
1743 		return true;
1744 
1745 	case DSO_BINARY_TYPE__BPF_PROG_INFO:
1746 	case DSO_BINARY_TYPE__BPF_IMAGE:
1747 	case DSO_BINARY_TYPE__OOL:
1748 	case DSO_BINARY_TYPE__NOT_FOUND:
1749 	default:
1750 		return false;
1751 	}
1752 }
1753 
1754 /* Checks for the existence of the perf-<pid>.map file in two different
1755  * locations.  First, if the process is a separate mount namespace, check in
1756  * that namespace using the pid of the innermost pid namespace.  If's not in a
1757  * namespace, or the file can't be found there, try in the mount namespace of
1758  * the tracing process using our view of its pid.
1759  */
dso__find_perf_map(char * filebuf,size_t bufsz,struct nsinfo ** nsip)1760 static int dso__find_perf_map(char *filebuf, size_t bufsz,
1761 			      struct nsinfo **nsip)
1762 {
1763 	struct nscookie nsc;
1764 	struct nsinfo *nsi;
1765 	struct nsinfo *nnsi;
1766 	int rc = -1;
1767 
1768 	nsi = *nsip;
1769 
1770 	if (nsinfo__need_setns(nsi)) {
1771 		snprintf(filebuf, bufsz, "/tmp/perf-%d.map", nsinfo__nstgid(nsi));
1772 		nsinfo__mountns_enter(nsi, &nsc);
1773 		rc = access(filebuf, R_OK);
1774 		nsinfo__mountns_exit(&nsc);
1775 		if (rc == 0)
1776 			return rc;
1777 	}
1778 
1779 	nnsi = nsinfo__copy(nsi);
1780 	if (nnsi) {
1781 		nsinfo__put(nsi);
1782 
1783 		nsinfo__clear_need_setns(nnsi);
1784 		snprintf(filebuf, bufsz, "/tmp/perf-%d.map", nsinfo__tgid(nnsi));
1785 		*nsip = nnsi;
1786 		rc = 0;
1787 	}
1788 
1789 	return rc;
1790 }
1791 
dso__load(struct dso * dso,struct map * map)1792 int dso__load(struct dso *dso, struct map *map)
1793 {
1794 	char *name;
1795 	int ret = -1;
1796 	u_int i;
1797 	struct machine *machine = NULL;
1798 	char *root_dir = (char *) "";
1799 	int ss_pos = 0;
1800 	struct symsrc ss_[2];
1801 	struct symsrc *syms_ss = NULL, *runtime_ss = NULL;
1802 	bool kmod;
1803 	bool perfmap;
1804 	struct build_id bid;
1805 	struct nscookie nsc;
1806 	char newmapname[PATH_MAX];
1807 	const char *map_path = dso__long_name(dso);
1808 
1809 	mutex_lock(dso__lock(dso));
1810 	perfmap = is_perf_pid_map_name(map_path);
1811 
1812 	if (perfmap) {
1813 		if (dso__nsinfo(dso) &&
1814 		    (dso__find_perf_map(newmapname, sizeof(newmapname),
1815 					dso__nsinfo_ptr(dso)) == 0)) {
1816 			map_path = newmapname;
1817 		}
1818 	}
1819 
1820 	nsinfo__mountns_enter(dso__nsinfo(dso), &nsc);
1821 
1822 	/* check again under the dso->lock */
1823 	if (dso__loaded(dso)) {
1824 		ret = 1;
1825 		goto out;
1826 	}
1827 
1828 	kmod = dso__is_kmod(dso);
1829 
1830 	if (dso__kernel(dso) && !kmod) {
1831 		if (dso__kernel(dso) == DSO_SPACE__KERNEL)
1832 			ret = dso__load_kernel_sym(dso, map);
1833 		else if (dso__kernel(dso) == DSO_SPACE__KERNEL_GUEST)
1834 			ret = dso__load_guest_kernel_sym(dso, map);
1835 
1836 		machine = maps__machine(map__kmaps(map));
1837 		if (machine__is(machine, "x86_64"))
1838 			machine__map_x86_64_entry_trampolines(machine, dso);
1839 		goto out;
1840 	}
1841 
1842 	dso__set_adjust_symbols(dso, false);
1843 
1844 	if (perfmap) {
1845 		ret = dso__load_perf_map(map_path, dso);
1846 		dso__set_symtab_type(dso, ret > 0
1847 				? DSO_BINARY_TYPE__JAVA_JIT
1848 				: DSO_BINARY_TYPE__NOT_FOUND);
1849 		goto out;
1850 	}
1851 
1852 	if (machine)
1853 		root_dir = machine->root_dir;
1854 
1855 	name = malloc(PATH_MAX);
1856 	if (!name)
1857 		goto out;
1858 
1859 	/*
1860 	 * Read the build id if possible. This is required for
1861 	 * DSO_BINARY_TYPE__BUILDID_DEBUGINFO to work
1862 	 */
1863 	if (!dso__has_build_id(dso) &&
1864 	    is_regular_file(dso__long_name(dso))) {
1865 		__symbol__join_symfs(name, PATH_MAX, dso__long_name(dso));
1866 		if (filename__read_build_id(name, &bid) > 0)
1867 			dso__set_build_id(dso, &bid);
1868 	}
1869 
1870 	/*
1871 	 * Iterate over candidate debug images.
1872 	 * Keep track of "interesting" ones (those which have a symtab, dynsym,
1873 	 * and/or opd section) for processing.
1874 	 */
1875 	for (i = 0; i < DSO_BINARY_TYPE__SYMTAB_CNT; i++) {
1876 		struct symsrc *ss = &ss_[ss_pos];
1877 		bool next_slot = false;
1878 		bool is_reg;
1879 		bool nsexit;
1880 		int bfdrc = -1;
1881 		int sirc = -1;
1882 
1883 		enum dso_binary_type symtab_type = binary_type_symtab[i];
1884 
1885 		nsexit = (symtab_type == DSO_BINARY_TYPE__BUILD_ID_CACHE ||
1886 		    symtab_type == DSO_BINARY_TYPE__BUILD_ID_CACHE_DEBUGINFO);
1887 
1888 		if (!dso__is_compatible_symtab_type(dso, kmod, symtab_type))
1889 			continue;
1890 
1891 		if (dso__read_binary_type_filename(dso, symtab_type,
1892 						   root_dir, name, PATH_MAX))
1893 			continue;
1894 
1895 		if (nsexit)
1896 			nsinfo__mountns_exit(&nsc);
1897 
1898 		is_reg = is_regular_file(name);
1899 		if (!is_reg && errno == ENOENT && dso__nsinfo(dso)) {
1900 			char *new_name = dso__filename_with_chroot(dso, name);
1901 			if (new_name) {
1902 				is_reg = is_regular_file(new_name);
1903 				strlcpy(name, new_name, PATH_MAX);
1904 				free(new_name);
1905 			}
1906 		}
1907 
1908 #ifdef HAVE_LIBBFD_SUPPORT
1909 		if (is_reg)
1910 			bfdrc = dso__load_bfd_symbols(dso, name);
1911 #endif
1912 		if (is_reg && bfdrc < 0)
1913 			sirc = symsrc__init(ss, dso, name, symtab_type);
1914 
1915 		if (nsexit)
1916 			nsinfo__mountns_enter(dso__nsinfo(dso), &nsc);
1917 
1918 		if (bfdrc == 0) {
1919 			ret = 0;
1920 			break;
1921 		}
1922 
1923 		if (!is_reg || sirc < 0)
1924 			continue;
1925 
1926 		if (!syms_ss && symsrc__has_symtab(ss)) {
1927 			syms_ss = ss;
1928 			next_slot = true;
1929 			if (!dso__symsrc_filename(dso))
1930 				dso__set_symsrc_filename(dso, strdup(name));
1931 		}
1932 
1933 		if (!runtime_ss && symsrc__possibly_runtime(ss)) {
1934 			runtime_ss = ss;
1935 			next_slot = true;
1936 		}
1937 
1938 		if (next_slot) {
1939 			ss_pos++;
1940 
1941 			if (dso__binary_type(dso) == DSO_BINARY_TYPE__NOT_FOUND)
1942 				dso__set_binary_type(dso, symtab_type);
1943 
1944 			if (syms_ss && runtime_ss)
1945 				break;
1946 		} else {
1947 			symsrc__destroy(ss);
1948 		}
1949 
1950 	}
1951 
1952 	if (!runtime_ss && !syms_ss)
1953 		goto out_free;
1954 
1955 	if (runtime_ss && !syms_ss) {
1956 		syms_ss = runtime_ss;
1957 	}
1958 
1959 	/* We'll have to hope for the best */
1960 	if (!runtime_ss && syms_ss)
1961 		runtime_ss = syms_ss;
1962 
1963 	if (syms_ss)
1964 		ret = dso__load_sym(dso, map, syms_ss, runtime_ss, kmod);
1965 	else
1966 		ret = -1;
1967 
1968 	if (ret > 0) {
1969 		int nr_plt;
1970 
1971 		nr_plt = dso__synthesize_plt_symbols(dso, runtime_ss);
1972 		if (nr_plt > 0)
1973 			ret += nr_plt;
1974 	}
1975 
1976 	for (; ss_pos > 0; ss_pos--)
1977 		symsrc__destroy(&ss_[ss_pos - 1]);
1978 out_free:
1979 	free(name);
1980 	if (ret < 0 && strstr(dso__name(dso), " (deleted)") != NULL)
1981 		ret = 0;
1982 out:
1983 	dso__set_loaded(dso);
1984 	mutex_unlock(dso__lock(dso));
1985 	nsinfo__mountns_exit(&nsc);
1986 
1987 	return ret;
1988 }
1989 
1990 /*
1991  * Always takes ownership of vmlinux when vmlinux_allocated == true, even if
1992  * it returns an error.
1993  */
dso__load_vmlinux(struct dso * dso,struct map * map,const char * vmlinux,bool vmlinux_allocated)1994 int dso__load_vmlinux(struct dso *dso, struct map *map,
1995 		      const char *vmlinux, bool vmlinux_allocated)
1996 {
1997 	int err = -1;
1998 	struct symsrc ss;
1999 	char symfs_vmlinux[PATH_MAX];
2000 	enum dso_binary_type symtab_type;
2001 
2002 	if (vmlinux[0] == '/')
2003 		snprintf(symfs_vmlinux, sizeof(symfs_vmlinux), "%s", vmlinux);
2004 	else
2005 		symbol__join_symfs(symfs_vmlinux, vmlinux);
2006 
2007 	if (dso__kernel(dso) == DSO_SPACE__KERNEL_GUEST)
2008 		symtab_type = DSO_BINARY_TYPE__GUEST_VMLINUX;
2009 	else
2010 		symtab_type = DSO_BINARY_TYPE__VMLINUX;
2011 
2012 	if (symsrc__init(&ss, dso, symfs_vmlinux, symtab_type)) {
2013 		if (vmlinux_allocated)
2014 			free((char *) vmlinux);
2015 		return -1;
2016 	}
2017 
2018 	/*
2019 	 * dso__load_sym() may copy 'dso' which will result in the copies having
2020 	 * an incorrect long name unless we set it here first.
2021 	 */
2022 	dso__set_long_name(dso, vmlinux, vmlinux_allocated);
2023 	if (dso__kernel(dso) == DSO_SPACE__KERNEL_GUEST)
2024 		dso__set_binary_type(dso, DSO_BINARY_TYPE__GUEST_VMLINUX);
2025 	else
2026 		dso__set_binary_type(dso, DSO_BINARY_TYPE__VMLINUX);
2027 
2028 	err = dso__load_sym(dso, map, &ss, &ss, 0);
2029 	symsrc__destroy(&ss);
2030 
2031 	if (err > 0) {
2032 		dso__set_loaded(dso);
2033 		pr_debug("Using %s for symbols\n", symfs_vmlinux);
2034 	}
2035 
2036 	return err;
2037 }
2038 
dso__load_vmlinux_path(struct dso * dso,struct map * map)2039 int dso__load_vmlinux_path(struct dso *dso, struct map *map)
2040 {
2041 	int i, err = 0;
2042 	char *filename = NULL;
2043 
2044 	pr_debug("Looking at the vmlinux_path (%d entries long)\n",
2045 		 vmlinux_path__nr_entries + 1);
2046 
2047 	for (i = 0; i < vmlinux_path__nr_entries; ++i) {
2048 		err = dso__load_vmlinux(dso, map, vmlinux_path[i], false);
2049 		if (err > 0)
2050 			goto out;
2051 	}
2052 
2053 	if (!symbol_conf.ignore_vmlinux_buildid)
2054 		filename = dso__build_id_filename(dso, NULL, 0, false);
2055 	if (filename != NULL) {
2056 		err = dso__load_vmlinux(dso, map, filename, true);
2057 		if (err > 0)
2058 			goto out;
2059 	}
2060 out:
2061 	return err;
2062 }
2063 
visible_dir_filter(const char * name,struct dirent * d)2064 static bool visible_dir_filter(const char *name, struct dirent *d)
2065 {
2066 	if (d->d_type != DT_DIR)
2067 		return false;
2068 	return lsdir_no_dot_filter(name, d);
2069 }
2070 
find_matching_kcore(struct map * map,char * dir,size_t dir_sz)2071 static int find_matching_kcore(struct map *map, char *dir, size_t dir_sz)
2072 {
2073 	char kallsyms_filename[PATH_MAX];
2074 	int ret = -1;
2075 	struct strlist *dirs;
2076 	struct str_node *nd;
2077 
2078 	dirs = lsdir(dir, visible_dir_filter);
2079 	if (!dirs)
2080 		return -1;
2081 
2082 	strlist__for_each_entry(nd, dirs) {
2083 		scnprintf(kallsyms_filename, sizeof(kallsyms_filename),
2084 			  "%s/%s/kallsyms", dir, nd->s);
2085 		if (!validate_kcore_addresses(kallsyms_filename, map)) {
2086 			strlcpy(dir, kallsyms_filename, dir_sz);
2087 			ret = 0;
2088 			break;
2089 		}
2090 	}
2091 
2092 	strlist__delete(dirs);
2093 
2094 	return ret;
2095 }
2096 
2097 /*
2098  * Use open(O_RDONLY) to check readability directly instead of access(R_OK)
2099  * since access(R_OK) only checks with real UID/GID but open() use effective
2100  * UID/GID and actual capabilities (e.g. /proc/kcore requires CAP_SYS_RAWIO).
2101  */
filename__readable(const char * file)2102 static bool filename__readable(const char *file)
2103 {
2104 	int fd = open(file, O_RDONLY);
2105 	if (fd < 0)
2106 		return false;
2107 	close(fd);
2108 	return true;
2109 }
2110 
dso__find_kallsyms(struct dso * dso,struct map * map)2111 static char *dso__find_kallsyms(struct dso *dso, struct map *map)
2112 {
2113 	struct build_id bid;
2114 	char sbuild_id[SBUILD_ID_SIZE];
2115 	bool is_host = false;
2116 	char path[PATH_MAX];
2117 
2118 	if (!dso__has_build_id(dso)) {
2119 		/*
2120 		 * Last resort, if we don't have a build-id and couldn't find
2121 		 * any vmlinux file, try the running kernel kallsyms table.
2122 		 */
2123 		goto proc_kallsyms;
2124 	}
2125 
2126 	if (sysfs__read_build_id("/sys/kernel/notes", &bid) == 0)
2127 		is_host = dso__build_id_equal(dso, &bid);
2128 
2129 	/* Try a fast path for /proc/kallsyms if possible */
2130 	if (is_host) {
2131 		/*
2132 		 * Do not check the build-id cache, unless we know we cannot use
2133 		 * /proc/kcore or module maps don't match to /proc/kallsyms.
2134 		 * To check readability of /proc/kcore, do not use access(R_OK)
2135 		 * since /proc/kcore requires CAP_SYS_RAWIO to read and access
2136 		 * can't check it.
2137 		 */
2138 		if (filename__readable("/proc/kcore") &&
2139 		    !validate_kcore_addresses("/proc/kallsyms", map))
2140 			goto proc_kallsyms;
2141 	}
2142 
2143 	build_id__sprintf(dso__bid(dso), sbuild_id);
2144 
2145 	/* Find kallsyms in build-id cache with kcore */
2146 	scnprintf(path, sizeof(path), "%s/%s/%s",
2147 		  buildid_dir, DSO__NAME_KCORE, sbuild_id);
2148 
2149 	if (!find_matching_kcore(map, path, sizeof(path)))
2150 		return strdup(path);
2151 
2152 	/* Use current /proc/kallsyms if possible */
2153 	if (is_host) {
2154 proc_kallsyms:
2155 		return strdup("/proc/kallsyms");
2156 	}
2157 
2158 	/* Finally, find a cache of kallsyms */
2159 	if (!build_id_cache__kallsyms_path(sbuild_id, path, sizeof(path))) {
2160 		pr_err("No kallsyms or vmlinux with build-id %s was found\n",
2161 		       sbuild_id);
2162 		return NULL;
2163 	}
2164 
2165 	return strdup(path);
2166 }
2167 
dso__load_kernel_sym(struct dso * dso,struct map * map)2168 static int dso__load_kernel_sym(struct dso *dso, struct map *map)
2169 {
2170 	int err;
2171 	const char *kallsyms_filename = NULL;
2172 	char *kallsyms_allocated_filename = NULL;
2173 	char *filename = NULL;
2174 
2175 	/*
2176 	 * Step 1: if the user specified a kallsyms or vmlinux filename, use
2177 	 * it and only it, reporting errors to the user if it cannot be used.
2178 	 *
2179 	 * For instance, try to analyse an ARM perf.data file _without_ a
2180 	 * build-id, or if the user specifies the wrong path to the right
2181 	 * vmlinux file, obviously we can't fallback to another vmlinux (a
2182 	 * x86_86 one, on the machine where analysis is being performed, say),
2183 	 * or worse, /proc/kallsyms.
2184 	 *
2185 	 * If the specified file _has_ a build-id and there is a build-id
2186 	 * section in the perf.data file, we will still do the expected
2187 	 * validation in dso__load_vmlinux and will bail out if they don't
2188 	 * match.
2189 	 */
2190 	if (symbol_conf.kallsyms_name != NULL) {
2191 		kallsyms_filename = symbol_conf.kallsyms_name;
2192 		goto do_kallsyms;
2193 	}
2194 
2195 	if (!symbol_conf.ignore_vmlinux && symbol_conf.vmlinux_name != NULL) {
2196 		return dso__load_vmlinux(dso, map, symbol_conf.vmlinux_name, false);
2197 	}
2198 
2199 	/*
2200 	 * Before checking on common vmlinux locations, check if it's
2201 	 * stored as standard build id binary (not kallsyms) under
2202 	 * .debug cache.
2203 	 */
2204 	if (!symbol_conf.ignore_vmlinux_buildid)
2205 		filename = __dso__build_id_filename(dso, NULL, 0, false, false);
2206 	if (filename != NULL) {
2207 		err = dso__load_vmlinux(dso, map, filename, true);
2208 		if (err > 0)
2209 			return err;
2210 	}
2211 
2212 	if (!symbol_conf.ignore_vmlinux && vmlinux_path != NULL) {
2213 		err = dso__load_vmlinux_path(dso, map);
2214 		if (err > 0)
2215 			return err;
2216 	}
2217 
2218 	/* do not try local files if a symfs was given */
2219 	if (symbol_conf.symfs[0] != 0)
2220 		return -1;
2221 
2222 	kallsyms_allocated_filename = dso__find_kallsyms(dso, map);
2223 	if (!kallsyms_allocated_filename)
2224 		return -1;
2225 
2226 	kallsyms_filename = kallsyms_allocated_filename;
2227 
2228 do_kallsyms:
2229 	err = dso__load_kallsyms(dso, kallsyms_filename, map);
2230 	if (err > 0)
2231 		pr_debug("Using %s for symbols\n", kallsyms_filename);
2232 	free(kallsyms_allocated_filename);
2233 
2234 	if (err > 0 && !dso__is_kcore(dso)) {
2235 		dso__set_binary_type(dso, DSO_BINARY_TYPE__KALLSYMS);
2236 		dso__set_long_name(dso, DSO__NAME_KALLSYMS, false);
2237 		map__fixup_start(map);
2238 		map__fixup_end(map);
2239 	}
2240 
2241 	return err;
2242 }
2243 
dso__load_guest_kernel_sym(struct dso * dso,struct map * map)2244 static int dso__load_guest_kernel_sym(struct dso *dso, struct map *map)
2245 {
2246 	int err;
2247 	const char *kallsyms_filename;
2248 	struct machine *machine = maps__machine(map__kmaps(map));
2249 	char path[PATH_MAX];
2250 
2251 	if (machine->kallsyms_filename) {
2252 		kallsyms_filename = machine->kallsyms_filename;
2253 	} else if (machine__is_default_guest(machine)) {
2254 		/*
2255 		 * if the user specified a vmlinux filename, use it and only
2256 		 * it, reporting errors to the user if it cannot be used.
2257 		 * Or use file guest_kallsyms inputted by user on commandline
2258 		 */
2259 		if (symbol_conf.default_guest_vmlinux_name != NULL) {
2260 			err = dso__load_vmlinux(dso, map,
2261 						symbol_conf.default_guest_vmlinux_name,
2262 						false);
2263 			return err;
2264 		}
2265 
2266 		kallsyms_filename = symbol_conf.default_guest_kallsyms;
2267 		if (!kallsyms_filename)
2268 			return -1;
2269 	} else {
2270 		sprintf(path, "%s/proc/kallsyms", machine->root_dir);
2271 		kallsyms_filename = path;
2272 	}
2273 
2274 	err = dso__load_kallsyms(dso, kallsyms_filename, map);
2275 	if (err > 0)
2276 		pr_debug("Using %s for symbols\n", kallsyms_filename);
2277 	if (err > 0 && !dso__is_kcore(dso)) {
2278 		dso__set_binary_type(dso, DSO_BINARY_TYPE__GUEST_KALLSYMS);
2279 		dso__set_long_name(dso, machine->mmap_name, false);
2280 		map__fixup_start(map);
2281 		map__fixup_end(map);
2282 	}
2283 
2284 	return err;
2285 }
2286 
vmlinux_path__exit(void)2287 static void vmlinux_path__exit(void)
2288 {
2289 	while (--vmlinux_path__nr_entries >= 0)
2290 		zfree(&vmlinux_path[vmlinux_path__nr_entries]);
2291 	vmlinux_path__nr_entries = 0;
2292 
2293 	zfree(&vmlinux_path);
2294 }
2295 
2296 static const char * const vmlinux_paths[] = {
2297 	"vmlinux",
2298 	"/boot/vmlinux"
2299 };
2300 
2301 static const char * const vmlinux_paths_upd[] = {
2302 	"/boot/vmlinux-%s",
2303 	"/usr/lib/debug/boot/vmlinux-%s",
2304 	"/lib/modules/%s/build/vmlinux",
2305 	"/usr/lib/debug/lib/modules/%s/vmlinux",
2306 	"/usr/lib/debug/boot/vmlinux-%s.debug"
2307 };
2308 
vmlinux_path__add(const char * new_entry)2309 static int vmlinux_path__add(const char *new_entry)
2310 {
2311 	vmlinux_path[vmlinux_path__nr_entries] = strdup(new_entry);
2312 	if (vmlinux_path[vmlinux_path__nr_entries] == NULL)
2313 		return -1;
2314 	++vmlinux_path__nr_entries;
2315 
2316 	return 0;
2317 }
2318 
vmlinux_path__init(struct perf_env * env)2319 static int vmlinux_path__init(struct perf_env *env)
2320 {
2321 	struct utsname uts;
2322 	char bf[PATH_MAX];
2323 	char *kernel_version;
2324 	unsigned int i;
2325 
2326 	vmlinux_path = malloc(sizeof(char *) * (ARRAY_SIZE(vmlinux_paths) +
2327 			      ARRAY_SIZE(vmlinux_paths_upd)));
2328 	if (vmlinux_path == NULL)
2329 		return -1;
2330 
2331 	for (i = 0; i < ARRAY_SIZE(vmlinux_paths); i++)
2332 		if (vmlinux_path__add(vmlinux_paths[i]) < 0)
2333 			goto out_fail;
2334 
2335 	/* only try kernel version if no symfs was given */
2336 	if (symbol_conf.symfs[0] != 0)
2337 		return 0;
2338 
2339 	if (env) {
2340 		kernel_version = env->os_release;
2341 	} else {
2342 		if (uname(&uts) < 0)
2343 			goto out_fail;
2344 
2345 		kernel_version = uts.release;
2346 	}
2347 
2348 	for (i = 0; i < ARRAY_SIZE(vmlinux_paths_upd); i++) {
2349 		snprintf(bf, sizeof(bf), vmlinux_paths_upd[i], kernel_version);
2350 		if (vmlinux_path__add(bf) < 0)
2351 			goto out_fail;
2352 	}
2353 
2354 	return 0;
2355 
2356 out_fail:
2357 	vmlinux_path__exit();
2358 	return -1;
2359 }
2360 
setup_list(struct strlist ** list,const char * list_str,const char * list_name)2361 int setup_list(struct strlist **list, const char *list_str,
2362 		      const char *list_name)
2363 {
2364 	if (list_str == NULL)
2365 		return 0;
2366 
2367 	*list = strlist__new(list_str, NULL);
2368 	if (!*list) {
2369 		pr_err("problems parsing %s list\n", list_name);
2370 		return -1;
2371 	}
2372 
2373 	symbol_conf.has_filter = true;
2374 	return 0;
2375 }
2376 
setup_intlist(struct intlist ** list,const char * list_str,const char * list_name)2377 int setup_intlist(struct intlist **list, const char *list_str,
2378 		  const char *list_name)
2379 {
2380 	if (list_str == NULL)
2381 		return 0;
2382 
2383 	*list = intlist__new(list_str);
2384 	if (!*list) {
2385 		pr_err("problems parsing %s list\n", list_name);
2386 		return -1;
2387 	}
2388 	return 0;
2389 }
2390 
setup_addrlist(struct intlist ** addr_list,struct strlist * sym_list)2391 static int setup_addrlist(struct intlist **addr_list, struct strlist *sym_list)
2392 {
2393 	struct str_node *pos, *tmp;
2394 	unsigned long val;
2395 	char *sep;
2396 	const char *end;
2397 	int i = 0, err;
2398 
2399 	*addr_list = intlist__new(NULL);
2400 	if (!*addr_list)
2401 		return -1;
2402 
2403 	strlist__for_each_entry_safe(pos, tmp, sym_list) {
2404 		errno = 0;
2405 		val = strtoul(pos->s, &sep, 16);
2406 		if (errno || (sep == pos->s))
2407 			continue;
2408 
2409 		if (*sep != '\0') {
2410 			end = pos->s + strlen(pos->s) - 1;
2411 			while (end >= sep && isspace(*end))
2412 				end--;
2413 
2414 			if (end >= sep)
2415 				continue;
2416 		}
2417 
2418 		err = intlist__add(*addr_list, val);
2419 		if (err)
2420 			break;
2421 
2422 		strlist__remove(sym_list, pos);
2423 		i++;
2424 	}
2425 
2426 	if (i == 0) {
2427 		intlist__delete(*addr_list);
2428 		*addr_list = NULL;
2429 	}
2430 
2431 	return 0;
2432 }
2433 
symbol__read_kptr_restrict(void)2434 static bool symbol__read_kptr_restrict(void)
2435 {
2436 	bool value = false;
2437 	FILE *fp = fopen("/proc/sys/kernel/kptr_restrict", "r");
2438 	bool used_root;
2439 	bool cap_syslog = perf_cap__capable(CAP_SYSLOG, &used_root);
2440 
2441 	if (fp != NULL) {
2442 		char line[8];
2443 
2444 		if (fgets(line, sizeof(line), fp) != NULL)
2445 			value = cap_syslog ? (atoi(line) >= 2) : (atoi(line) != 0);
2446 
2447 		fclose(fp);
2448 	}
2449 
2450 	/* Per kernel/kallsyms.c:
2451 	 * we also restrict when perf_event_paranoid > 1 w/o CAP_SYSLOG
2452 	 */
2453 	if (perf_event_paranoid() > 1 && !cap_syslog)
2454 		value = true;
2455 
2456 	return value;
2457 }
2458 
symbol__annotation_init(void)2459 int symbol__annotation_init(void)
2460 {
2461 	if (symbol_conf.init_annotation)
2462 		return 0;
2463 
2464 	if (symbol_conf.initialized) {
2465 		pr_err("Annotation needs to be init before symbol__init()\n");
2466 		return -1;
2467 	}
2468 
2469 	symbol_conf.priv_size += sizeof(struct annotation);
2470 	symbol_conf.init_annotation = true;
2471 	return 0;
2472 }
2473 
symbol__init(struct perf_env * env)2474 int symbol__init(struct perf_env *env)
2475 {
2476 	const char *symfs;
2477 
2478 	if (symbol_conf.initialized)
2479 		return 0;
2480 
2481 	symbol_conf.priv_size = PERF_ALIGN(symbol_conf.priv_size, sizeof(u64));
2482 
2483 	symbol__elf_init();
2484 
2485 	if (symbol_conf.try_vmlinux_path && vmlinux_path__init(env) < 0)
2486 		return -1;
2487 
2488 	if (symbol_conf.field_sep && *symbol_conf.field_sep == '.') {
2489 		pr_err("'.' is the only non valid --field-separator argument\n");
2490 		return -1;
2491 	}
2492 
2493 	if (setup_list(&symbol_conf.dso_list,
2494 		       symbol_conf.dso_list_str, "dso") < 0)
2495 		return -1;
2496 
2497 	if (setup_list(&symbol_conf.comm_list,
2498 		       symbol_conf.comm_list_str, "comm") < 0)
2499 		goto out_free_dso_list;
2500 
2501 	if (setup_intlist(&symbol_conf.pid_list,
2502 		       symbol_conf.pid_list_str, "pid") < 0)
2503 		goto out_free_comm_list;
2504 
2505 	if (setup_intlist(&symbol_conf.tid_list,
2506 		       symbol_conf.tid_list_str, "tid") < 0)
2507 		goto out_free_pid_list;
2508 
2509 	if (setup_list(&symbol_conf.sym_list,
2510 		       symbol_conf.sym_list_str, "symbol") < 0)
2511 		goto out_free_tid_list;
2512 
2513 	if (symbol_conf.sym_list &&
2514 	    setup_addrlist(&symbol_conf.addr_list, symbol_conf.sym_list) < 0)
2515 		goto out_free_sym_list;
2516 
2517 	if (setup_list(&symbol_conf.bt_stop_list,
2518 		       symbol_conf.bt_stop_list_str, "symbol") < 0)
2519 		goto out_free_sym_list;
2520 
2521 	/*
2522 	 * A path to symbols of "/" is identical to ""
2523 	 * reset here for simplicity.
2524 	 */
2525 	symfs = realpath(symbol_conf.symfs, NULL);
2526 	if (symfs == NULL)
2527 		symfs = symbol_conf.symfs;
2528 	if (strcmp(symfs, "/") == 0)
2529 		symbol_conf.symfs = "";
2530 	if (symfs != symbol_conf.symfs)
2531 		free((void *)symfs);
2532 
2533 	symbol_conf.kptr_restrict = symbol__read_kptr_restrict();
2534 
2535 	symbol_conf.initialized = true;
2536 	return 0;
2537 
2538 out_free_sym_list:
2539 	strlist__delete(symbol_conf.sym_list);
2540 	intlist__delete(symbol_conf.addr_list);
2541 out_free_tid_list:
2542 	intlist__delete(symbol_conf.tid_list);
2543 out_free_pid_list:
2544 	intlist__delete(symbol_conf.pid_list);
2545 out_free_comm_list:
2546 	strlist__delete(symbol_conf.comm_list);
2547 out_free_dso_list:
2548 	strlist__delete(symbol_conf.dso_list);
2549 	return -1;
2550 }
2551 
symbol__exit(void)2552 void symbol__exit(void)
2553 {
2554 	if (!symbol_conf.initialized)
2555 		return;
2556 	strlist__delete(symbol_conf.bt_stop_list);
2557 	strlist__delete(symbol_conf.sym_list);
2558 	strlist__delete(symbol_conf.dso_list);
2559 	strlist__delete(symbol_conf.comm_list);
2560 	intlist__delete(symbol_conf.tid_list);
2561 	intlist__delete(symbol_conf.pid_list);
2562 	intlist__delete(symbol_conf.addr_list);
2563 	vmlinux_path__exit();
2564 	symbol_conf.sym_list = symbol_conf.dso_list = symbol_conf.comm_list = NULL;
2565 	symbol_conf.bt_stop_list = NULL;
2566 	symbol_conf.initialized = false;
2567 }
2568 
symbol__config_symfs(const struct option * opt __maybe_unused,const char * dir,int unset __maybe_unused)2569 int symbol__config_symfs(const struct option *opt __maybe_unused,
2570 			 const char *dir, int unset __maybe_unused)
2571 {
2572 	char *bf = NULL;
2573 	int ret;
2574 
2575 	symbol_conf.symfs = strdup(dir);
2576 	if (symbol_conf.symfs == NULL)
2577 		return -ENOMEM;
2578 
2579 	/* skip the locally configured cache if a symfs is given, and
2580 	 * config buildid dir to symfs/.debug
2581 	 */
2582 	ret = asprintf(&bf, "%s/%s", dir, ".debug");
2583 	if (ret < 0)
2584 		return -ENOMEM;
2585 
2586 	set_buildid_dir(bf);
2587 
2588 	free(bf);
2589 	return 0;
2590 }
2591 
2592 /*
2593  * Checks that user supplied symbol kernel files are accessible because
2594  * the default mechanism for accessing elf files fails silently. i.e. if
2595  * debug syms for a build ID aren't found perf carries on normally. When
2596  * they are user supplied we should assume that the user doesn't want to
2597  * silently fail.
2598  */
symbol__validate_sym_arguments(void)2599 int symbol__validate_sym_arguments(void)
2600 {
2601 	if (symbol_conf.vmlinux_name &&
2602 	    access(symbol_conf.vmlinux_name, R_OK)) {
2603 		pr_err("Invalid file: %s\n", symbol_conf.vmlinux_name);
2604 		return -EINVAL;
2605 	}
2606 	if (symbol_conf.kallsyms_name &&
2607 	    access(symbol_conf.kallsyms_name, R_OK)) {
2608 		pr_err("Invalid file: %s\n", symbol_conf.kallsyms_name);
2609 		return -EINVAL;
2610 	}
2611 	return 0;
2612 }
2613