xref: /linux/tools/perf/util/annotate-data.c (revision 4d6d6e0f61e2267103e9b013d2a82d04ff278127)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 /*
3  * Convert sample address to data type using DWARF debug info.
4  *
5  * Written by Namhyung Kim <namhyung@kernel.org>
6  */
7 
8 #include <stdio.h>
9 #include <stdlib.h>
10 #include <inttypes.h>
11 #include <linux/zalloc.h>
12 
13 #include "annotate.h"
14 #include "annotate-data.h"
15 #include "debuginfo.h"
16 #include "debug.h"
17 #include "dso.h"
18 #include "dwarf-regs.h"
19 #include "evsel.h"
20 #include "evlist.h"
21 #include "map.h"
22 #include "map_symbol.h"
23 #include "sort.h"
24 #include "strbuf.h"
25 #include "symbol.h"
26 #include "symbol_conf.h"
27 #include "thread.h"
28 
29 /* register number of the stack pointer */
30 #define X86_REG_SP 7
31 
32 static void delete_var_types(struct die_var_type *var_types);
33 
34 #define pr_debug_dtp(fmt, ...)					\
35 do {								\
36 	if (debug_type_profile)					\
37 		pr_info(fmt, ##__VA_ARGS__);			\
38 	else							\
39 		pr_debug3(fmt, ##__VA_ARGS__);			\
40 } while (0)
41 
42 void pr_debug_type_name(Dwarf_Die *die, enum type_state_kind kind)
43 {
44 	struct strbuf sb;
45 	char *str;
46 	Dwarf_Word size = 0;
47 
48 	if (!debug_type_profile && verbose < 3)
49 		return;
50 
51 	switch (kind) {
52 	case TSR_KIND_INVALID:
53 		pr_info("\n");
54 		return;
55 	case TSR_KIND_PERCPU_BASE:
56 		pr_info(" percpu base\n");
57 		return;
58 	case TSR_KIND_CONST:
59 		pr_info(" constant\n");
60 		return;
61 	case TSR_KIND_POINTER:
62 		pr_info(" pointer");
63 		/* it also prints the type info */
64 		break;
65 	case TSR_KIND_CANARY:
66 		pr_info(" stack canary\n");
67 		return;
68 	case TSR_KIND_TYPE:
69 	default:
70 		break;
71 	}
72 
73 	dwarf_aggregate_size(die, &size);
74 
75 	strbuf_init(&sb, 32);
76 	die_get_typename_from_type(die, &sb);
77 	str = strbuf_detach(&sb, NULL);
78 	pr_info(" type='%s' size=%#lx (die:%#lx)\n",
79 		str, (long)size, (long)dwarf_dieoffset(die));
80 	free(str);
81 }
82 
83 static void pr_debug_location(Dwarf_Die *die, u64 pc, int reg)
84 {
85 	ptrdiff_t off = 0;
86 	Dwarf_Attribute attr;
87 	Dwarf_Addr base, start, end;
88 	Dwarf_Op *ops;
89 	size_t nops;
90 
91 	if (!debug_type_profile && verbose < 3)
92 		return;
93 
94 	if (dwarf_attr(die, DW_AT_location, &attr) == NULL)
95 		return;
96 
97 	while ((off = dwarf_getlocations(&attr, off, &base, &start, &end, &ops, &nops)) > 0) {
98 		if (reg != DWARF_REG_PC && end <= pc)
99 			continue;
100 		if (reg != DWARF_REG_PC && start > pc)
101 			break;
102 
103 		pr_info(" variable location: ");
104 		switch (ops->atom) {
105 		case DW_OP_reg0 ...DW_OP_reg31:
106 			pr_info("reg%d\n", ops->atom - DW_OP_reg0);
107 			break;
108 		case DW_OP_breg0 ...DW_OP_breg31:
109 			pr_info("base=reg%d, offset=%#lx\n",
110 				ops->atom - DW_OP_breg0, (long)ops->number);
111 			break;
112 		case DW_OP_regx:
113 			pr_info("reg%ld\n", (long)ops->number);
114 			break;
115 		case DW_OP_bregx:
116 			pr_info("base=reg%ld, offset=%#lx\n",
117 				(long)ops->number, (long)ops->number2);
118 			break;
119 		case DW_OP_fbreg:
120 			pr_info("use frame base, offset=%#lx\n", (long)ops->number);
121 			break;
122 		case DW_OP_addr:
123 			pr_info("address=%#lx\n", (long)ops->number);
124 			break;
125 		default:
126 			pr_info("unknown: code=%#x, number=%#lx\n",
127 				ops->atom, (long)ops->number);
128 			break;
129 		}
130 		break;
131 	}
132 }
133 
134 bool has_reg_type(struct type_state *state, int reg)
135 {
136 	return (unsigned)reg < ARRAY_SIZE(state->regs);
137 }
138 
139 static void init_type_state(struct type_state *state, struct arch *arch)
140 {
141 	memset(state, 0, sizeof(*state));
142 	INIT_LIST_HEAD(&state->stack_vars);
143 
144 	if (arch__is(arch, "x86")) {
145 		state->regs[0].caller_saved = true;
146 		state->regs[1].caller_saved = true;
147 		state->regs[2].caller_saved = true;
148 		state->regs[4].caller_saved = true;
149 		state->regs[5].caller_saved = true;
150 		state->regs[8].caller_saved = true;
151 		state->regs[9].caller_saved = true;
152 		state->regs[10].caller_saved = true;
153 		state->regs[11].caller_saved = true;
154 		state->ret_reg = 0;
155 		state->stack_reg = X86_REG_SP;
156 	}
157 }
158 
159 static void exit_type_state(struct type_state *state)
160 {
161 	struct type_state_stack *stack, *tmp;
162 
163 	list_for_each_entry_safe(stack, tmp, &state->stack_vars, list) {
164 		list_del(&stack->list);
165 		free(stack);
166 	}
167 }
168 
169 /*
170  * Compare type name and size to maintain them in a tree.
171  * I'm not sure if DWARF would have information of a single type in many
172  * different places (compilation units).  If not, it could compare the
173  * offset of the type entry in the .debug_info section.
174  */
175 static int data_type_cmp(const void *_key, const struct rb_node *node)
176 {
177 	const struct annotated_data_type *key = _key;
178 	struct annotated_data_type *type;
179 
180 	type = rb_entry(node, struct annotated_data_type, node);
181 
182 	if (key->self.size != type->self.size)
183 		return key->self.size - type->self.size;
184 	return strcmp(key->self.type_name, type->self.type_name);
185 }
186 
187 static bool data_type_less(struct rb_node *node_a, const struct rb_node *node_b)
188 {
189 	struct annotated_data_type *a, *b;
190 
191 	a = rb_entry(node_a, struct annotated_data_type, node);
192 	b = rb_entry(node_b, struct annotated_data_type, node);
193 
194 	if (a->self.size != b->self.size)
195 		return a->self.size < b->self.size;
196 	return strcmp(a->self.type_name, b->self.type_name) < 0;
197 }
198 
199 /* Recursively add new members for struct/union */
200 static int __add_member_cb(Dwarf_Die *die, void *arg)
201 {
202 	struct annotated_member *parent = arg;
203 	struct annotated_member *member;
204 	Dwarf_Die member_type, die_mem;
205 	Dwarf_Word size, loc, bit_size = 0;
206 	Dwarf_Attribute attr;
207 	struct strbuf sb;
208 	int tag;
209 
210 	if (dwarf_tag(die) != DW_TAG_member)
211 		return DIE_FIND_CB_SIBLING;
212 
213 	member = zalloc(sizeof(*member));
214 	if (member == NULL)
215 		return DIE_FIND_CB_END;
216 
217 	strbuf_init(&sb, 32);
218 	die_get_typename(die, &sb);
219 
220 	__die_get_real_type(die, &member_type);
221 	if (dwarf_tag(&member_type) == DW_TAG_typedef)
222 		die_get_real_type(&member_type, &die_mem);
223 	else
224 		die_mem = member_type;
225 
226 	if (dwarf_aggregate_size(&die_mem, &size) < 0)
227 		size = 0;
228 
229 	if (dwarf_attr_integrate(die, DW_AT_data_member_location, &attr))
230 		dwarf_formudata(&attr, &loc);
231 	else {
232 		/* bitfield member */
233 		if (dwarf_attr_integrate(die, DW_AT_data_bit_offset, &attr) &&
234 		    dwarf_formudata(&attr, &loc) == 0)
235 			loc /= 8;
236 		else
237 			loc = 0;
238 
239 		if (dwarf_attr_integrate(die, DW_AT_bit_size, &attr) &&
240 		    dwarf_formudata(&attr, &bit_size) == 0)
241 			size = (bit_size + 7) / 8;
242 	}
243 
244 	member->type_name = strbuf_detach(&sb, NULL);
245 	/* member->var_name can be NULL */
246 	if (dwarf_diename(die)) {
247 		if (bit_size) {
248 			if (asprintf(&member->var_name, "%s:%ld",
249 				     dwarf_diename(die), (long)bit_size) < 0)
250 				member->var_name = NULL;
251 		} else {
252 			member->var_name = strdup(dwarf_diename(die));
253 		}
254 
255 		if (member->var_name == NULL) {
256 			free(member);
257 			return DIE_FIND_CB_END;
258 		}
259 	}
260 	member->size = size;
261 	member->offset = loc + parent->offset;
262 	INIT_LIST_HEAD(&member->children);
263 	list_add_tail(&member->node, &parent->children);
264 
265 	tag = dwarf_tag(&die_mem);
266 	switch (tag) {
267 	case DW_TAG_structure_type:
268 	case DW_TAG_union_type:
269 		die_find_child(&die_mem, __add_member_cb, member, &die_mem);
270 		break;
271 	default:
272 		break;
273 	}
274 	return DIE_FIND_CB_SIBLING;
275 }
276 
277 static void add_member_types(struct annotated_data_type *parent, Dwarf_Die *type)
278 {
279 	Dwarf_Die die_mem;
280 
281 	die_find_child(type, __add_member_cb, &parent->self, &die_mem);
282 }
283 
284 static void delete_members(struct annotated_member *member)
285 {
286 	struct annotated_member *child, *tmp;
287 
288 	list_for_each_entry_safe(child, tmp, &member->children, node) {
289 		list_del(&child->node);
290 		delete_members(child);
291 		zfree(&child->type_name);
292 		zfree(&child->var_name);
293 		free(child);
294 	}
295 }
296 
297 static struct annotated_data_type *dso__findnew_data_type(struct dso *dso,
298 							  Dwarf_Die *type_die)
299 {
300 	struct annotated_data_type *result = NULL;
301 	struct annotated_data_type key;
302 	struct rb_node *node;
303 	struct strbuf sb;
304 	char *type_name;
305 	Dwarf_Word size;
306 
307 	strbuf_init(&sb, 32);
308 	if (die_get_typename_from_type(type_die, &sb) < 0)
309 		strbuf_add(&sb, "(unknown type)", 14);
310 	type_name = strbuf_detach(&sb, NULL);
311 
312 	if (dwarf_tag(type_die) == DW_TAG_typedef)
313 		die_get_real_type(type_die, type_die);
314 
315 	dwarf_aggregate_size(type_die, &size);
316 
317 	/* Check existing nodes in dso->data_types tree */
318 	key.self.type_name = type_name;
319 	key.self.size = size;
320 	node = rb_find(&key, dso__data_types(dso), data_type_cmp);
321 	if (node) {
322 		result = rb_entry(node, struct annotated_data_type, node);
323 		free(type_name);
324 		return result;
325 	}
326 
327 	/* If not, add a new one */
328 	result = zalloc(sizeof(*result));
329 	if (result == NULL) {
330 		free(type_name);
331 		return NULL;
332 	}
333 
334 	result->self.type_name = type_name;
335 	result->self.size = size;
336 	INIT_LIST_HEAD(&result->self.children);
337 
338 	if (symbol_conf.annotate_data_member)
339 		add_member_types(result, type_die);
340 
341 	rb_add(&result->node, dso__data_types(dso), data_type_less);
342 	return result;
343 }
344 
345 static bool find_cu_die(struct debuginfo *di, u64 pc, Dwarf_Die *cu_die)
346 {
347 	Dwarf_Off off, next_off;
348 	size_t header_size;
349 
350 	if (dwarf_addrdie(di->dbg, pc, cu_die) != NULL)
351 		return cu_die;
352 
353 	/*
354 	 * There are some kernels don't have full aranges and contain only a few
355 	 * aranges entries.  Fallback to iterate all CU entries in .debug_info
356 	 * in case it's missing.
357 	 */
358 	off = 0;
359 	while (dwarf_nextcu(di->dbg, off, &next_off, &header_size,
360 			    NULL, NULL, NULL) == 0) {
361 		if (dwarf_offdie(di->dbg, off + header_size, cu_die) &&
362 		    dwarf_haspc(cu_die, pc))
363 			return true;
364 
365 		off = next_off;
366 	}
367 	return false;
368 }
369 
370 enum type_match_result {
371 	PERF_TMR_UNKNOWN = 0,
372 	PERF_TMR_OK,
373 	PERF_TMR_NO_TYPE,
374 	PERF_TMR_NO_POINTER,
375 	PERF_TMR_NO_SIZE,
376 	PERF_TMR_BAD_OFFSET,
377 	PERF_TMR_BAIL_OUT,
378 };
379 
380 static const char *match_result_str(enum type_match_result tmr)
381 {
382 	switch (tmr) {
383 	case PERF_TMR_OK:
384 		return "Good!";
385 	case PERF_TMR_NO_TYPE:
386 		return "no type information";
387 	case PERF_TMR_NO_POINTER:
388 		return "no/void pointer";
389 	case PERF_TMR_NO_SIZE:
390 		return "type size is unknown";
391 	case PERF_TMR_BAD_OFFSET:
392 		return "offset bigger than size";
393 	case PERF_TMR_UNKNOWN:
394 	case PERF_TMR_BAIL_OUT:
395 	default:
396 		return "invalid state";
397 	}
398 }
399 
400 static bool is_pointer_type(Dwarf_Die *type_die)
401 {
402 	int tag = dwarf_tag(type_die);
403 
404 	return tag == DW_TAG_pointer_type || tag == DW_TAG_array_type;
405 }
406 
407 static bool is_compound_type(Dwarf_Die *type_die)
408 {
409 	int tag = dwarf_tag(type_die);
410 
411 	return tag == DW_TAG_structure_type || tag == DW_TAG_union_type;
412 }
413 
414 /* returns if Type B has better information than Type A */
415 static bool is_better_type(Dwarf_Die *type_a, Dwarf_Die *type_b)
416 {
417 	Dwarf_Word size_a, size_b;
418 	Dwarf_Die die_a, die_b;
419 
420 	/* pointer type is preferred */
421 	if (is_pointer_type(type_a) != is_pointer_type(type_b))
422 		return is_pointer_type(type_b);
423 
424 	if (is_pointer_type(type_b)) {
425 		/*
426 		 * We want to compare the target type, but 'void *' can fail to
427 		 * get the target type.
428 		 */
429 		if (die_get_real_type(type_a, &die_a) == NULL)
430 			return true;
431 		if (die_get_real_type(type_b, &die_b) == NULL)
432 			return false;
433 
434 		type_a = &die_a;
435 		type_b = &die_b;
436 	}
437 
438 	/* bigger type is preferred */
439 	if (dwarf_aggregate_size(type_a, &size_a) < 0 ||
440 	    dwarf_aggregate_size(type_b, &size_b) < 0)
441 		return false;
442 
443 	if (size_a != size_b)
444 		return size_a < size_b;
445 
446 	/* struct or union is preferred */
447 	if (is_compound_type(type_a) != is_compound_type(type_b))
448 		return is_compound_type(type_b);
449 
450 	/* typedef is preferred */
451 	if (dwarf_tag(type_b) == DW_TAG_typedef)
452 		return true;
453 
454 	return false;
455 }
456 
457 /* The type info will be saved in @type_die */
458 static enum type_match_result check_variable(struct data_loc_info *dloc,
459 					     Dwarf_Die *var_die,
460 					     Dwarf_Die *type_die, int reg,
461 					     int offset, bool is_fbreg)
462 {
463 	Dwarf_Word size;
464 	bool needs_pointer = true;
465 	Dwarf_Die sized_type;
466 
467 	if (reg == DWARF_REG_PC)
468 		needs_pointer = false;
469 	else if (reg == dloc->fbreg || is_fbreg)
470 		needs_pointer = false;
471 	else if (arch__is(dloc->arch, "x86") && reg == X86_REG_SP)
472 		needs_pointer = false;
473 
474 	/* Get the type of the variable */
475 	if (__die_get_real_type(var_die, type_die) == NULL)
476 		return PERF_TMR_NO_TYPE;
477 
478 	/*
479 	 * Usually it expects a pointer type for a memory access.
480 	 * Convert to a real type it points to.  But global variables
481 	 * and local variables are accessed directly without a pointer.
482 	 */
483 	if (needs_pointer) {
484 		if (!is_pointer_type(type_die) ||
485 		    __die_get_real_type(type_die, type_die) == NULL)
486 			return PERF_TMR_NO_POINTER;
487 	}
488 
489 	if (dwarf_tag(type_die) == DW_TAG_typedef)
490 		die_get_real_type(type_die, &sized_type);
491 	else
492 		sized_type = *type_die;
493 
494 	/* Get the size of the actual type */
495 	if (dwarf_aggregate_size(&sized_type, &size) < 0)
496 		return PERF_TMR_NO_SIZE;
497 
498 	/* Minimal sanity check */
499 	if ((unsigned)offset >= size)
500 		return PERF_TMR_BAD_OFFSET;
501 
502 	return PERF_TMR_OK;
503 }
504 
505 struct type_state_stack *find_stack_state(struct type_state *state,
506 						 int offset)
507 {
508 	struct type_state_stack *stack;
509 
510 	list_for_each_entry(stack, &state->stack_vars, list) {
511 		if (offset == stack->offset)
512 			return stack;
513 
514 		if (stack->compound && stack->offset < offset &&
515 		    offset < stack->offset + stack->size)
516 			return stack;
517 	}
518 	return NULL;
519 }
520 
521 void set_stack_state(struct type_state_stack *stack, int offset, u8 kind,
522 			    Dwarf_Die *type_die)
523 {
524 	int tag;
525 	Dwarf_Word size;
526 
527 	if (dwarf_aggregate_size(type_die, &size) < 0)
528 		size = 0;
529 
530 	tag = dwarf_tag(type_die);
531 
532 	stack->type = *type_die;
533 	stack->size = size;
534 	stack->offset = offset;
535 	stack->kind = kind;
536 
537 	switch (tag) {
538 	case DW_TAG_structure_type:
539 	case DW_TAG_union_type:
540 		stack->compound = (kind != TSR_KIND_POINTER);
541 		break;
542 	default:
543 		stack->compound = false;
544 		break;
545 	}
546 }
547 
548 struct type_state_stack *findnew_stack_state(struct type_state *state,
549 						    int offset, u8 kind,
550 						    Dwarf_Die *type_die)
551 {
552 	struct type_state_stack *stack = find_stack_state(state, offset);
553 
554 	if (stack) {
555 		set_stack_state(stack, offset, kind, type_die);
556 		return stack;
557 	}
558 
559 	stack = malloc(sizeof(*stack));
560 	if (stack) {
561 		set_stack_state(stack, offset, kind, type_die);
562 		list_add(&stack->list, &state->stack_vars);
563 	}
564 	return stack;
565 }
566 
567 /* Maintain a cache for quick global variable lookup */
568 struct global_var_entry {
569 	struct rb_node node;
570 	char *name;
571 	u64 start;
572 	u64 end;
573 	u64 die_offset;
574 };
575 
576 static int global_var_cmp(const void *_key, const struct rb_node *node)
577 {
578 	const u64 addr = (uintptr_t)_key;
579 	struct global_var_entry *gvar;
580 
581 	gvar = rb_entry(node, struct global_var_entry, node);
582 
583 	if (gvar->start <= addr && addr < gvar->end)
584 		return 0;
585 	return gvar->start > addr ? -1 : 1;
586 }
587 
588 static bool global_var_less(struct rb_node *node_a, const struct rb_node *node_b)
589 {
590 	struct global_var_entry *gvar_a, *gvar_b;
591 
592 	gvar_a = rb_entry(node_a, struct global_var_entry, node);
593 	gvar_b = rb_entry(node_b, struct global_var_entry, node);
594 
595 	return gvar_a->start < gvar_b->start;
596 }
597 
598 static struct global_var_entry *global_var__find(struct data_loc_info *dloc, u64 addr)
599 {
600 	struct dso *dso = map__dso(dloc->ms->map);
601 	struct rb_node *node;
602 
603 	node = rb_find((void *)(uintptr_t)addr, dso__global_vars(dso), global_var_cmp);
604 	if (node == NULL)
605 		return NULL;
606 
607 	return rb_entry(node, struct global_var_entry, node);
608 }
609 
610 static bool global_var__add(struct data_loc_info *dloc, u64 addr,
611 			    const char *name, Dwarf_Die *type_die)
612 {
613 	struct dso *dso = map__dso(dloc->ms->map);
614 	struct global_var_entry *gvar;
615 	Dwarf_Word size;
616 
617 	if (dwarf_aggregate_size(type_die, &size) < 0)
618 		return false;
619 
620 	gvar = malloc(sizeof(*gvar));
621 	if (gvar == NULL)
622 		return false;
623 
624 	gvar->name = name ? strdup(name) : NULL;
625 	if (name && gvar->name == NULL) {
626 		free(gvar);
627 		return false;
628 	}
629 
630 	gvar->start = addr;
631 	gvar->end = addr + size;
632 	gvar->die_offset = dwarf_dieoffset(type_die);
633 
634 	rb_add(&gvar->node, dso__global_vars(dso), global_var_less);
635 	return true;
636 }
637 
638 void global_var_type__tree_delete(struct rb_root *root)
639 {
640 	struct global_var_entry *gvar;
641 
642 	while (!RB_EMPTY_ROOT(root)) {
643 		struct rb_node *node = rb_first(root);
644 
645 		rb_erase(node, root);
646 		gvar = rb_entry(node, struct global_var_entry, node);
647 		zfree(&gvar->name);
648 		free(gvar);
649 	}
650 }
651 
652 bool get_global_var_info(struct data_loc_info *dloc, u64 addr,
653 				const char **var_name, int *var_offset)
654 {
655 	struct addr_location al;
656 	struct symbol *sym;
657 	u64 mem_addr;
658 
659 	/* Kernel symbols might be relocated */
660 	mem_addr = addr + map__reloc(dloc->ms->map);
661 
662 	addr_location__init(&al);
663 	sym = thread__find_symbol_fb(dloc->thread, dloc->cpumode,
664 				     mem_addr, &al);
665 	if (sym) {
666 		*var_name = sym->name;
667 		/* Calculate type offset from the start of variable */
668 		*var_offset = mem_addr - map__unmap_ip(al.map, sym->start);
669 	} else {
670 		*var_name = NULL;
671 	}
672 	addr_location__exit(&al);
673 	if (*var_name == NULL)
674 		return false;
675 
676 	return true;
677 }
678 
679 static void global_var__collect(struct data_loc_info *dloc)
680 {
681 	Dwarf *dwarf = dloc->di->dbg;
682 	Dwarf_Off off, next_off;
683 	Dwarf_Die cu_die, type_die;
684 	size_t header_size;
685 
686 	/* Iterate all CU and collect global variables that have no location in a register. */
687 	off = 0;
688 	while (dwarf_nextcu(dwarf, off, &next_off, &header_size,
689 			    NULL, NULL, NULL) == 0) {
690 		struct die_var_type *var_types = NULL;
691 		struct die_var_type *pos;
692 
693 		if (dwarf_offdie(dwarf, off + header_size, &cu_die) == NULL) {
694 			off = next_off;
695 			continue;
696 		}
697 
698 		die_collect_global_vars(&cu_die, &var_types);
699 
700 		for (pos = var_types; pos; pos = pos->next) {
701 			const char *var_name = NULL;
702 			int var_offset = 0;
703 
704 			if (pos->reg != -1)
705 				continue;
706 
707 			if (!dwarf_offdie(dwarf, pos->die_off, &type_die))
708 				continue;
709 
710 			if (!get_global_var_info(dloc, pos->addr, &var_name,
711 						 &var_offset))
712 				continue;
713 
714 			if (var_offset != 0)
715 				continue;
716 
717 			global_var__add(dloc, pos->addr, var_name, &type_die);
718 		}
719 
720 		delete_var_types(var_types);
721 
722 		off = next_off;
723 	}
724 }
725 
726 bool get_global_var_type(Dwarf_Die *cu_die, struct data_loc_info *dloc,
727 				u64 ip, u64 var_addr, int *var_offset,
728 				Dwarf_Die *type_die)
729 {
730 	u64 pc;
731 	int offset;
732 	const char *var_name = NULL;
733 	struct global_var_entry *gvar;
734 	struct dso *dso = map__dso(dloc->ms->map);
735 	Dwarf_Die var_die;
736 
737 	if (RB_EMPTY_ROOT(dso__global_vars(dso)))
738 		global_var__collect(dloc);
739 
740 	gvar = global_var__find(dloc, var_addr);
741 	if (gvar) {
742 		if (!dwarf_offdie(dloc->di->dbg, gvar->die_offset, type_die))
743 			return false;
744 
745 		*var_offset = var_addr - gvar->start;
746 		return true;
747 	}
748 
749 	/* Try to get the variable by address first */
750 	if (die_find_variable_by_addr(cu_die, var_addr, &var_die, &offset) &&
751 	    check_variable(dloc, &var_die, type_die, DWARF_REG_PC, offset,
752 			   /*is_fbreg=*/false) == PERF_TMR_OK) {
753 		var_name = dwarf_diename(&var_die);
754 		*var_offset = offset;
755 		goto ok;
756 	}
757 
758 	if (!get_global_var_info(dloc, var_addr, &var_name, var_offset))
759 		return false;
760 
761 	pc = map__rip_2objdump(dloc->ms->map, ip);
762 
763 	/* Try to get the name of global variable */
764 	if (die_find_variable_at(cu_die, var_name, pc, &var_die) &&
765 	    check_variable(dloc, &var_die, type_die, DWARF_REG_PC, *var_offset,
766 			   /*is_fbreg=*/false) == PERF_TMR_OK)
767 		goto ok;
768 
769 	return false;
770 
771 ok:
772 	/* The address should point to the start of the variable */
773 	global_var__add(dloc, var_addr - *var_offset, var_name, type_die);
774 	return true;
775 }
776 
777 /**
778  * update_var_state - Update type state using given variables
779  * @state: type state table
780  * @dloc: data location info
781  * @addr: instruction address to match with variable
782  * @insn_offset: instruction offset (for debug)
783  * @var_types: list of variables with type info
784  *
785  * This function fills the @state table using @var_types info.  Each variable
786  * is used only at the given location and updates an entry in the table.
787  */
788 static void update_var_state(struct type_state *state, struct data_loc_info *dloc,
789 			     u64 addr, u64 insn_offset, struct die_var_type *var_types)
790 {
791 	Dwarf_Die mem_die;
792 	struct die_var_type *var;
793 	int fbreg = dloc->fbreg;
794 	int fb_offset = 0;
795 
796 	if (dloc->fb_cfa) {
797 		if (die_get_cfa(dloc->di->dbg, addr, &fbreg, &fb_offset) < 0)
798 			fbreg = -1;
799 	}
800 
801 	for (var = var_types; var != NULL; var = var->next) {
802 		if (var->addr != addr)
803 			continue;
804 		/* Get the type DIE using the offset */
805 		if (!dwarf_offdie(dloc->di->dbg, var->die_off, &mem_die))
806 			continue;
807 
808 		if (var->reg == DWARF_REG_FB || var->reg == fbreg) {
809 			int offset = var->offset;
810 			struct type_state_stack *stack;
811 
812 			if (var->reg != DWARF_REG_FB)
813 				offset -= fb_offset;
814 
815 			stack = find_stack_state(state, offset);
816 			if (stack && stack->kind == TSR_KIND_TYPE &&
817 			    !is_better_type(&stack->type, &mem_die))
818 				continue;
819 
820 			findnew_stack_state(state, offset, TSR_KIND_TYPE,
821 					    &mem_die);
822 
823 			pr_debug_dtp("var [%"PRIx64"] -%#x(stack)",
824 				     insn_offset, -offset);
825 			pr_debug_type_name(&mem_die, TSR_KIND_TYPE);
826 		} else if (has_reg_type(state, var->reg) && var->offset == 0) {
827 			struct type_state_reg *reg;
828 
829 			reg = &state->regs[var->reg];
830 
831 			if (reg->ok && reg->kind == TSR_KIND_TYPE &&
832 			    !is_better_type(&reg->type, &mem_die))
833 				continue;
834 
835 			reg->type = mem_die;
836 			reg->kind = TSR_KIND_TYPE;
837 			reg->ok = true;
838 
839 			pr_debug_dtp("var [%"PRIx64"] reg%d",
840 				     insn_offset, var->reg);
841 			pr_debug_type_name(&mem_die, TSR_KIND_TYPE);
842 		}
843 	}
844 }
845 
846 /**
847  * update_insn_state - Update type state for an instruction
848  * @state: type state table
849  * @dloc: data location info
850  * @cu_die: compile unit debug entry
851  * @dl: disasm line for the instruction
852  *
853  * This function updates the @state table for the target operand of the
854  * instruction at @dl if it transfers the type like MOV on x86.  Since it
855  * tracks the type, it won't care about the values like in arithmetic
856  * instructions like ADD/SUB/MUL/DIV and INC/DEC.
857  *
858  * Note that ops->reg2 is only available when both mem_ref and multi_regs
859  * are true.
860  */
861 static void update_insn_state(struct type_state *state, struct data_loc_info *dloc,
862 			      Dwarf_Die *cu_die, struct disasm_line *dl)
863 {
864 	if (dloc->arch->update_insn_state)
865 		dloc->arch->update_insn_state(state, dloc, cu_die, dl);
866 }
867 
868 /*
869  * Prepend this_blocks (from the outer scope) to full_blocks, removing
870  * duplicate disasm line.
871  */
872 static void prepend_basic_blocks(struct list_head *this_blocks,
873 				 struct list_head *full_blocks)
874 {
875 	struct annotated_basic_block *first_bb, *last_bb;
876 
877 	last_bb = list_last_entry(this_blocks, typeof(*last_bb), list);
878 	first_bb = list_first_entry(full_blocks, typeof(*first_bb), list);
879 
880 	if (list_empty(full_blocks))
881 		goto out;
882 
883 	/* Last insn in this_blocks should be same as first insn in full_blocks */
884 	if (last_bb->end != first_bb->begin) {
885 		pr_debug("prepend basic blocks: mismatched disasm line %"PRIx64" -> %"PRIx64"\n",
886 			 last_bb->end->al.offset, first_bb->begin->al.offset);
887 		goto out;
888 	}
889 
890 	/* Is the basic block have only one disasm_line? */
891 	if (last_bb->begin == last_bb->end) {
892 		list_del(&last_bb->list);
893 		free(last_bb);
894 		goto out;
895 	}
896 
897 	/* Point to the insn before the last when adding this block to full_blocks */
898 	last_bb->end = list_prev_entry(last_bb->end, al.node);
899 
900 out:
901 	list_splice(this_blocks, full_blocks);
902 }
903 
904 static void delete_basic_blocks(struct list_head *basic_blocks)
905 {
906 	struct annotated_basic_block *bb, *tmp;
907 
908 	list_for_each_entry_safe(bb, tmp, basic_blocks, list) {
909 		list_del(&bb->list);
910 		free(bb);
911 	}
912 }
913 
914 /* Make sure all variables have a valid start address */
915 static void fixup_var_address(struct die_var_type *var_types, u64 addr)
916 {
917 	while (var_types) {
918 		/*
919 		 * Some variables have no address range meaning it's always
920 		 * available in the whole scope.  Let's adjust the start
921 		 * address to the start of the scope.
922 		 */
923 		if (var_types->addr == 0)
924 			var_types->addr = addr;
925 
926 		var_types = var_types->next;
927 	}
928 }
929 
930 static void delete_var_types(struct die_var_type *var_types)
931 {
932 	while (var_types) {
933 		struct die_var_type *next = var_types->next;
934 
935 		free(var_types);
936 		var_types = next;
937 	}
938 }
939 
940 /* should match to is_stack_canary() in util/annotate.c */
941 static void setup_stack_canary(struct data_loc_info *dloc)
942 {
943 	if (arch__is(dloc->arch, "x86")) {
944 		dloc->op->segment = INSN_SEG_X86_GS;
945 		dloc->op->imm = true;
946 		dloc->op->offset = 40;
947 	}
948 }
949 
950 /*
951  * It's at the target address, check if it has a matching type.
952  * It returns PERF_TMR_BAIL_OUT when it looks up per-cpu variables which
953  * are similar to global variables and no additional info is needed.
954  */
955 static enum type_match_result check_matching_type(struct type_state *state,
956 						  struct data_loc_info *dloc,
957 						  Dwarf_Die *cu_die,
958 						  Dwarf_Die *type_die)
959 {
960 	Dwarf_Word size;
961 	u32 insn_offset = dloc->ip - dloc->ms->sym->start;
962 	int reg = dloc->op->reg1;
963 
964 	pr_debug_dtp("chk [%x] reg%d offset=%#x ok=%d kind=%d ",
965 		     insn_offset, reg, dloc->op->offset,
966 		     state->regs[reg].ok, state->regs[reg].kind);
967 
968 	if (!state->regs[reg].ok)
969 		goto check_non_register;
970 
971 	if (state->regs[reg].kind == TSR_KIND_TYPE) {
972 		Dwarf_Die sized_type;
973 
974 		/*
975 		 * Normal registers should hold a pointer (or array) to
976 		 * dereference a memory location.
977 		 */
978 		if (!is_pointer_type(&state->regs[reg].type)) {
979 			if (dloc->op->offset < 0 && reg != state->stack_reg)
980 				goto check_kernel;
981 
982 			return PERF_TMR_NO_POINTER;
983 		}
984 
985 		/* Remove the pointer and get the target type */
986 		if (__die_get_real_type(&state->regs[reg].type, type_die) == NULL)
987 			return PERF_TMR_NO_POINTER;
988 
989 		dloc->type_offset = dloc->op->offset;
990 
991 		if (dwarf_tag(type_die) == DW_TAG_typedef)
992 			die_get_real_type(type_die, &sized_type);
993 		else
994 			sized_type = *type_die;
995 
996 		/* Get the size of the actual type */
997 		if (dwarf_aggregate_size(&sized_type, &size) < 0 ||
998 		    (unsigned)dloc->type_offset >= size)
999 			return PERF_TMR_BAD_OFFSET;
1000 
1001 		return PERF_TMR_OK;
1002 	}
1003 
1004 	if (state->regs[reg].kind == TSR_KIND_POINTER) {
1005 		pr_debug_dtp("percpu ptr");
1006 
1007 		/*
1008 		 * It's actaully pointer but the address was calculated using
1009 		 * some arithmetic.  So it points to the actual type already.
1010 		 */
1011 		*type_die = state->regs[reg].type;
1012 
1013 		dloc->type_offset = dloc->op->offset;
1014 
1015 		/* Get the size of the actual type */
1016 		if (dwarf_aggregate_size(type_die, &size) < 0 ||
1017 		    (unsigned)dloc->type_offset >= size)
1018 			return PERF_TMR_BAIL_OUT;
1019 
1020 		return PERF_TMR_OK;
1021 	}
1022 
1023 	if (state->regs[reg].kind == TSR_KIND_CANARY) {
1024 		pr_debug_dtp("stack canary");
1025 
1026 		/*
1027 		 * This is a saved value of the stack canary which will be handled
1028 		 * in the outer logic when it returns failure here.  Pretend it's
1029 		 * from the stack canary directly.
1030 		 */
1031 		setup_stack_canary(dloc);
1032 
1033 		return PERF_TMR_BAIL_OUT;
1034 	}
1035 
1036 	if (state->regs[reg].kind == TSR_KIND_PERCPU_BASE) {
1037 		u64 var_addr = dloc->op->offset;
1038 		int var_offset;
1039 
1040 		pr_debug_dtp("percpu var");
1041 
1042 		if (dloc->op->multi_regs) {
1043 			int reg2 = dloc->op->reg2;
1044 
1045 			if (dloc->op->reg2 == reg)
1046 				reg2 = dloc->op->reg1;
1047 
1048 			if (has_reg_type(state, reg2) && state->regs[reg2].ok &&
1049 			    state->regs[reg2].kind == TSR_KIND_CONST)
1050 				var_addr += state->regs[reg2].imm_value;
1051 		}
1052 
1053 		if (get_global_var_type(cu_die, dloc, dloc->ip, var_addr,
1054 					&var_offset, type_die)) {
1055 			dloc->type_offset = var_offset;
1056 			return PERF_TMR_OK;
1057 		}
1058 		/* No need to retry per-cpu (global) variables */
1059 		return PERF_TMR_BAIL_OUT;
1060 	}
1061 
1062 check_non_register:
1063 	if (reg == dloc->fbreg) {
1064 		struct type_state_stack *stack;
1065 
1066 		pr_debug_dtp("fbreg");
1067 
1068 		stack = find_stack_state(state, dloc->type_offset);
1069 		if (stack == NULL)
1070 			return PERF_TMR_NO_TYPE;
1071 
1072 		if (stack->kind == TSR_KIND_CANARY) {
1073 			setup_stack_canary(dloc);
1074 			return PERF_TMR_BAIL_OUT;
1075 		}
1076 
1077 		if (stack->kind != TSR_KIND_TYPE)
1078 			return PERF_TMR_NO_TYPE;
1079 
1080 		*type_die = stack->type;
1081 		/* Update the type offset from the start of slot */
1082 		dloc->type_offset -= stack->offset;
1083 
1084 		return PERF_TMR_OK;
1085 	}
1086 
1087 	if (dloc->fb_cfa) {
1088 		struct type_state_stack *stack;
1089 		u64 pc = map__rip_2objdump(dloc->ms->map, dloc->ip);
1090 		int fbreg, fboff;
1091 
1092 		pr_debug_dtp("cfa");
1093 
1094 		if (die_get_cfa(dloc->di->dbg, pc, &fbreg, &fboff) < 0)
1095 			fbreg = -1;
1096 
1097 		if (reg != fbreg)
1098 			return PERF_TMR_NO_TYPE;
1099 
1100 		stack = find_stack_state(state, dloc->type_offset - fboff);
1101 		if (stack == NULL)
1102 			return PERF_TMR_NO_TYPE;
1103 
1104 		if (stack->kind == TSR_KIND_CANARY) {
1105 			setup_stack_canary(dloc);
1106 			return PERF_TMR_BAIL_OUT;
1107 		}
1108 
1109 		if (stack->kind != TSR_KIND_TYPE)
1110 			return PERF_TMR_NO_TYPE;
1111 
1112 		*type_die = stack->type;
1113 		/* Update the type offset from the start of slot */
1114 		dloc->type_offset -= fboff + stack->offset;
1115 
1116 		return PERF_TMR_OK;
1117 	}
1118 
1119 check_kernel:
1120 	if (dso__kernel(map__dso(dloc->ms->map))) {
1121 		u64 addr;
1122 		int offset;
1123 
1124 		/* Direct this-cpu access like "%gs:0x34740" */
1125 		if (dloc->op->segment == INSN_SEG_X86_GS && dloc->op->imm &&
1126 		    arch__is(dloc->arch, "x86")) {
1127 			pr_debug_dtp("this-cpu var");
1128 
1129 			addr = dloc->op->offset;
1130 
1131 			if (get_global_var_type(cu_die, dloc, dloc->ip, addr,
1132 						&offset, type_die)) {
1133 				dloc->type_offset = offset;
1134 				return PERF_TMR_OK;
1135 			}
1136 			return PERF_TMR_BAIL_OUT;
1137 		}
1138 
1139 		/* Access to global variable like "-0x7dcf0500(,%rdx,8)" */
1140 		if (dloc->op->offset < 0 && reg != state->stack_reg) {
1141 			addr = (s64) dloc->op->offset;
1142 
1143 			if (get_global_var_type(cu_die, dloc, dloc->ip, addr,
1144 						&offset, type_die)) {
1145 				pr_debug_dtp("global var");
1146 
1147 				dloc->type_offset = offset;
1148 				return PERF_TMR_OK;
1149 			}
1150 			return PERF_TMR_BAIL_OUT;
1151 		}
1152 	}
1153 
1154 	return PERF_TMR_UNKNOWN;
1155 }
1156 
1157 /* Iterate instructions in basic blocks and update type table */
1158 static enum type_match_result find_data_type_insn(struct data_loc_info *dloc,
1159 						  struct list_head *basic_blocks,
1160 						  struct die_var_type *var_types,
1161 						  Dwarf_Die *cu_die,
1162 						  Dwarf_Die *type_die)
1163 {
1164 	struct type_state state;
1165 	struct symbol *sym = dloc->ms->sym;
1166 	struct annotation *notes = symbol__annotation(sym);
1167 	struct annotated_basic_block *bb;
1168 	enum type_match_result ret = PERF_TMR_UNKNOWN;
1169 
1170 	init_type_state(&state, dloc->arch);
1171 
1172 	list_for_each_entry(bb, basic_blocks, list) {
1173 		struct disasm_line *dl = bb->begin;
1174 
1175 		BUG_ON(bb->begin->al.offset == -1 || bb->end->al.offset == -1);
1176 
1177 		pr_debug_dtp("bb: [%"PRIx64" - %"PRIx64"]\n",
1178 			     bb->begin->al.offset, bb->end->al.offset);
1179 
1180 		list_for_each_entry_from(dl, &notes->src->source, al.node) {
1181 			u64 this_ip = sym->start + dl->al.offset;
1182 			u64 addr = map__rip_2objdump(dloc->ms->map, this_ip);
1183 
1184 			/* Skip comment or debug info lines */
1185 			if (dl->al.offset == -1)
1186 				continue;
1187 
1188 			/* Update variable type at this address */
1189 			update_var_state(&state, dloc, addr, dl->al.offset, var_types);
1190 
1191 			if (this_ip == dloc->ip) {
1192 				ret = check_matching_type(&state, dloc,
1193 							  cu_die, type_die);
1194 				pr_debug_dtp(" : %s\n", match_result_str(ret));
1195 				goto out;
1196 			}
1197 
1198 			/* Update type table after processing the instruction */
1199 			update_insn_state(&state, dloc, cu_die, dl);
1200 			if (dl == bb->end)
1201 				break;
1202 		}
1203 	}
1204 
1205 out:
1206 	exit_type_state(&state);
1207 	return ret;
1208 }
1209 
1210 static int arch_supports_insn_tracking(struct data_loc_info *dloc)
1211 {
1212 	if ((arch__is(dloc->arch, "x86")) || (arch__is(dloc->arch, "powerpc")))
1213 		return 1;
1214 	return 0;
1215 }
1216 
1217 /*
1218  * Construct a list of basic blocks for each scope with variables and try to find
1219  * the data type by updating a type state table through instructions.
1220  */
1221 static enum type_match_result find_data_type_block(struct data_loc_info *dloc,
1222 						   Dwarf_Die *cu_die,
1223 						   Dwarf_Die *scopes,
1224 						   int nr_scopes,
1225 						   Dwarf_Die *type_die)
1226 {
1227 	LIST_HEAD(basic_blocks);
1228 	struct die_var_type *var_types = NULL;
1229 	u64 src_ip, dst_ip, prev_dst_ip;
1230 	enum type_match_result ret = PERF_TMR_UNKNOWN;
1231 
1232 	/* TODO: other architecture support */
1233 	if (!arch_supports_insn_tracking(dloc))
1234 		return PERF_TMR_BAIL_OUT;
1235 
1236 	prev_dst_ip = dst_ip = dloc->ip;
1237 	for (int i = nr_scopes - 1; i >= 0; i--) {
1238 		Dwarf_Addr base, start, end;
1239 		LIST_HEAD(this_blocks);
1240 
1241 		if (dwarf_ranges(&scopes[i], 0, &base, &start, &end) < 0)
1242 			break;
1243 
1244 		pr_debug_dtp("scope: [%d/%d] (die:%lx)\n",
1245 			     i + 1, nr_scopes, (long)dwarf_dieoffset(&scopes[i]));
1246 		src_ip = map__objdump_2rip(dloc->ms->map, start);
1247 
1248 again:
1249 		/* Get basic blocks for this scope */
1250 		if (annotate_get_basic_blocks(dloc->ms->sym, src_ip, dst_ip,
1251 					      &this_blocks) < 0) {
1252 			/* Try previous block if they are not connected */
1253 			if (prev_dst_ip != dst_ip) {
1254 				dst_ip = prev_dst_ip;
1255 				goto again;
1256 			}
1257 
1258 			pr_debug_dtp("cannot find a basic block from %"PRIx64" to %"PRIx64"\n",
1259 				     src_ip - dloc->ms->sym->start,
1260 				     dst_ip - dloc->ms->sym->start);
1261 			continue;
1262 		}
1263 		prepend_basic_blocks(&this_blocks, &basic_blocks);
1264 
1265 		/* Get variable info for this scope and add to var_types list */
1266 		die_collect_vars(&scopes[i], &var_types);
1267 		fixup_var_address(var_types, start);
1268 
1269 		/* Find from start of this scope to the target instruction */
1270 		ret = find_data_type_insn(dloc, &basic_blocks, var_types,
1271 					    cu_die, type_die);
1272 		if (ret == PERF_TMR_OK) {
1273 			char buf[64];
1274 
1275 			if (dloc->op->multi_regs)
1276 				snprintf(buf, sizeof(buf), "reg%d, reg%d",
1277 					 dloc->op->reg1, dloc->op->reg2);
1278 			else
1279 				snprintf(buf, sizeof(buf), "reg%d", dloc->op->reg1);
1280 
1281 			pr_debug_dtp("found by insn track: %#x(%s) type-offset=%#x\n",
1282 				     dloc->op->offset, buf, dloc->type_offset);
1283 			break;
1284 		}
1285 
1286 		if (ret == PERF_TMR_BAIL_OUT)
1287 			break;
1288 
1289 		/* Go up to the next scope and find blocks to the start */
1290 		prev_dst_ip = dst_ip;
1291 		dst_ip = src_ip;
1292 	}
1293 
1294 	delete_basic_blocks(&basic_blocks);
1295 	delete_var_types(var_types);
1296 	return ret;
1297 }
1298 
1299 /* The result will be saved in @type_die */
1300 static int find_data_type_die(struct data_loc_info *dloc, Dwarf_Die *type_die)
1301 {
1302 	struct annotated_op_loc *loc = dloc->op;
1303 	Dwarf_Die cu_die, var_die;
1304 	Dwarf_Die *scopes = NULL;
1305 	int reg, offset;
1306 	int ret = -1;
1307 	int i, nr_scopes;
1308 	int fbreg = -1;
1309 	int fb_offset = 0;
1310 	bool is_fbreg = false;
1311 	bool found = false;
1312 	u64 pc;
1313 	char buf[64];
1314 	enum type_match_result result = PERF_TMR_UNKNOWN;
1315 
1316 	if (dloc->op->multi_regs)
1317 		snprintf(buf, sizeof(buf), "reg%d, reg%d", dloc->op->reg1, dloc->op->reg2);
1318 	else if (dloc->op->reg1 == DWARF_REG_PC)
1319 		snprintf(buf, sizeof(buf), "PC");
1320 	else
1321 		snprintf(buf, sizeof(buf), "reg%d", dloc->op->reg1);
1322 
1323 	pr_debug_dtp("-----------------------------------------------------------\n");
1324 	pr_debug_dtp("find data type for %#x(%s) at %s+%#"PRIx64"\n",
1325 		     dloc->op->offset, buf, dloc->ms->sym->name,
1326 		     dloc->ip - dloc->ms->sym->start);
1327 
1328 	/*
1329 	 * IP is a relative instruction address from the start of the map, as
1330 	 * it can be randomized/relocated, it needs to translate to PC which is
1331 	 * a file address for DWARF processing.
1332 	 */
1333 	pc = map__rip_2objdump(dloc->ms->map, dloc->ip);
1334 
1335 	/* Get a compile_unit for this address */
1336 	if (!find_cu_die(dloc->di, pc, &cu_die)) {
1337 		pr_debug_dtp("cannot find CU for address %"PRIx64"\n", pc);
1338 		ann_data_stat.no_cuinfo++;
1339 		return -1;
1340 	}
1341 
1342 	reg = loc->reg1;
1343 	offset = loc->offset;
1344 
1345 	pr_debug_dtp("CU for %s (die:%#lx)\n",
1346 		     dwarf_diename(&cu_die), (long)dwarf_dieoffset(&cu_die));
1347 
1348 	if (reg == DWARF_REG_PC) {
1349 		if (get_global_var_type(&cu_die, dloc, dloc->ip, dloc->var_addr,
1350 					&offset, type_die)) {
1351 			dloc->type_offset = offset;
1352 
1353 			pr_debug_dtp("found by addr=%#"PRIx64" type_offset=%#x\n",
1354 				     dloc->var_addr, offset);
1355 			pr_debug_type_name(type_die, TSR_KIND_TYPE);
1356 			found = true;
1357 			goto out;
1358 		}
1359 	}
1360 
1361 	/* Get a list of nested scopes - i.e. (inlined) functions and blocks. */
1362 	nr_scopes = die_get_scopes(&cu_die, pc, &scopes);
1363 
1364 	if (reg != DWARF_REG_PC && dwarf_hasattr(&scopes[0], DW_AT_frame_base)) {
1365 		Dwarf_Attribute attr;
1366 		Dwarf_Block block;
1367 
1368 		/* Check if the 'reg' is assigned as frame base register */
1369 		if (dwarf_attr(&scopes[0], DW_AT_frame_base, &attr) != NULL &&
1370 		    dwarf_formblock(&attr, &block) == 0 && block.length == 1) {
1371 			switch (*block.data) {
1372 			case DW_OP_reg0 ... DW_OP_reg31:
1373 				fbreg = dloc->fbreg = *block.data - DW_OP_reg0;
1374 				break;
1375 			case DW_OP_call_frame_cfa:
1376 				dloc->fb_cfa = true;
1377 				if (die_get_cfa(dloc->di->dbg, pc, &fbreg,
1378 						&fb_offset) < 0)
1379 					fbreg = -1;
1380 				break;
1381 			default:
1382 				break;
1383 			}
1384 
1385 			pr_debug_dtp("frame base: cfa=%d fbreg=%d\n",
1386 				     dloc->fb_cfa, fbreg);
1387 		}
1388 	}
1389 
1390 retry:
1391 	is_fbreg = (reg == fbreg);
1392 	if (is_fbreg)
1393 		offset = loc->offset - fb_offset;
1394 
1395 	/* Search from the inner-most scope to the outer */
1396 	for (i = nr_scopes - 1; i >= 0; i--) {
1397 		Dwarf_Die mem_die;
1398 		int type_offset = offset;
1399 
1400 		if (reg == DWARF_REG_PC) {
1401 			if (!die_find_variable_by_addr(&scopes[i], dloc->var_addr,
1402 						       &var_die, &type_offset))
1403 				continue;
1404 		} else {
1405 			/* Look up variables/parameters in this scope */
1406 			if (!die_find_variable_by_reg(&scopes[i], pc, reg,
1407 						      &type_offset, is_fbreg, &var_die))
1408 				continue;
1409 		}
1410 
1411 		pr_debug_dtp("found \"%s\" (die: %#lx) in scope=%d/%d (die: %#lx) ",
1412 			     dwarf_diename(&var_die), (long)dwarf_dieoffset(&var_die),
1413 			     i+1, nr_scopes, (long)dwarf_dieoffset(&scopes[i]));
1414 
1415 		/* Found a variable, see if it's correct */
1416 		result = check_variable(dloc, &var_die, &mem_die, reg, type_offset, is_fbreg);
1417 		if (result == PERF_TMR_OK) {
1418 			if (reg == DWARF_REG_PC) {
1419 				pr_debug_dtp("addr=%#"PRIx64" type_offset=%#x\n",
1420 					     dloc->var_addr, type_offset);
1421 			} else if (reg == DWARF_REG_FB || is_fbreg) {
1422 				pr_debug_dtp("stack_offset=%#x type_offset=%#x\n",
1423 					     fb_offset, type_offset);
1424 			} else {
1425 				pr_debug_dtp("type_offset=%#x\n", type_offset);
1426 			}
1427 
1428 			if (!found || is_better_type(type_die, &mem_die)) {
1429 				*type_die = mem_die;
1430 				dloc->type_offset = type_offset;
1431 				found = true;
1432 			}
1433 		} else {
1434 			pr_debug_dtp("failed: %s\n", match_result_str(result));
1435 		}
1436 
1437 		pr_debug_location(&var_die, pc, reg);
1438 		pr_debug_type_name(&mem_die, TSR_KIND_TYPE);
1439 	}
1440 
1441 	if (!found && loc->multi_regs && reg == loc->reg1 && loc->reg1 != loc->reg2) {
1442 		reg = loc->reg2;
1443 		goto retry;
1444 	}
1445 
1446 	if (!found && reg != DWARF_REG_PC) {
1447 		result = find_data_type_block(dloc, &cu_die, scopes,
1448 					      nr_scopes, type_die);
1449 		if (result == PERF_TMR_OK) {
1450 			ann_data_stat.insn_track++;
1451 			found = true;
1452 		}
1453 	}
1454 
1455 out:
1456 	if (found) {
1457 		pr_debug_dtp("final type:");
1458 		pr_debug_type_name(type_die, TSR_KIND_TYPE);
1459 		ret = 0;
1460 	} else {
1461 		switch (result) {
1462 		case PERF_TMR_NO_TYPE:
1463 		case PERF_TMR_NO_POINTER:
1464 			pr_debug_dtp("%s\n", match_result_str(result));
1465 			ann_data_stat.no_typeinfo++;
1466 			break;
1467 		case PERF_TMR_NO_SIZE:
1468 			pr_debug_dtp("%s\n", match_result_str(result));
1469 			ann_data_stat.invalid_size++;
1470 			break;
1471 		case PERF_TMR_BAD_OFFSET:
1472 			pr_debug_dtp("%s\n", match_result_str(result));
1473 			ann_data_stat.bad_offset++;
1474 			break;
1475 		case PERF_TMR_UNKNOWN:
1476 		case PERF_TMR_BAIL_OUT:
1477 		case PERF_TMR_OK:  /* should not reach here */
1478 		default:
1479 			pr_debug_dtp("no variable found\n");
1480 			ann_data_stat.no_var++;
1481 			break;
1482 		}
1483 		ret = -1;
1484 	}
1485 
1486 	free(scopes);
1487 	return ret;
1488 }
1489 
1490 /**
1491  * find_data_type - Return a data type at the location
1492  * @dloc: data location
1493  *
1494  * This functions searches the debug information of the binary to get the data
1495  * type it accesses.  The exact location is expressed by (ip, reg, offset)
1496  * for pointer variables or (ip, addr) for global variables.  Note that global
1497  * variables might update the @dloc->type_offset after finding the start of the
1498  * variable.  If it cannot find a global variable by address, it tried to find
1499  * a declaration of the variable using var_name.  In that case, @dloc->offset
1500  * won't be updated.
1501  *
1502  * It return %NULL if not found.
1503  */
1504 struct annotated_data_type *find_data_type(struct data_loc_info *dloc)
1505 {
1506 	struct dso *dso = map__dso(dloc->ms->map);
1507 	Dwarf_Die type_die;
1508 
1509 	/*
1510 	 * The type offset is the same as instruction offset by default.
1511 	 * But when finding a global variable, the offset won't be valid.
1512 	 */
1513 	dloc->type_offset = dloc->op->offset;
1514 
1515 	dloc->fbreg = -1;
1516 
1517 	if (find_data_type_die(dloc, &type_die) < 0)
1518 		return NULL;
1519 
1520 	return dso__findnew_data_type(dso, &type_die);
1521 }
1522 
1523 static int alloc_data_type_histograms(struct annotated_data_type *adt, int nr_entries)
1524 {
1525 	int i;
1526 	size_t sz = sizeof(struct type_hist);
1527 
1528 	sz += sizeof(struct type_hist_entry) * adt->self.size;
1529 
1530 	/* Allocate a table of pointers for each event */
1531 	adt->histograms = calloc(nr_entries, sizeof(*adt->histograms));
1532 	if (adt->histograms == NULL)
1533 		return -ENOMEM;
1534 
1535 	/*
1536 	 * Each histogram is allocated for the whole size of the type.
1537 	 * TODO: Probably we can move the histogram to members.
1538 	 */
1539 	for (i = 0; i < nr_entries; i++) {
1540 		adt->histograms[i] = zalloc(sz);
1541 		if (adt->histograms[i] == NULL)
1542 			goto err;
1543 	}
1544 
1545 	adt->nr_histograms = nr_entries;
1546 	return 0;
1547 
1548 err:
1549 	while (--i >= 0)
1550 		zfree(&(adt->histograms[i]));
1551 	zfree(&adt->histograms);
1552 	return -ENOMEM;
1553 }
1554 
1555 static void delete_data_type_histograms(struct annotated_data_type *adt)
1556 {
1557 	for (int i = 0; i < adt->nr_histograms; i++)
1558 		zfree(&(adt->histograms[i]));
1559 
1560 	zfree(&adt->histograms);
1561 	adt->nr_histograms = 0;
1562 }
1563 
1564 void annotated_data_type__tree_delete(struct rb_root *root)
1565 {
1566 	struct annotated_data_type *pos;
1567 
1568 	while (!RB_EMPTY_ROOT(root)) {
1569 		struct rb_node *node = rb_first(root);
1570 
1571 		rb_erase(node, root);
1572 		pos = rb_entry(node, struct annotated_data_type, node);
1573 		delete_members(&pos->self);
1574 		delete_data_type_histograms(pos);
1575 		zfree(&pos->self.type_name);
1576 		free(pos);
1577 	}
1578 }
1579 
1580 /**
1581  * annotated_data_type__update_samples - Update histogram
1582  * @adt: Data type to update
1583  * @evsel: Event to update
1584  * @offset: Offset in the type
1585  * @nr_samples: Number of samples at this offset
1586  * @period: Event count at this offset
1587  *
1588  * This function updates type histogram at @ofs for @evsel.  Samples are
1589  * aggregated before calling this function so it can be called with more
1590  * than one samples at a certain offset.
1591  */
1592 int annotated_data_type__update_samples(struct annotated_data_type *adt,
1593 					struct evsel *evsel, int offset,
1594 					int nr_samples, u64 period)
1595 {
1596 	struct type_hist *h;
1597 
1598 	if (adt == NULL)
1599 		return 0;
1600 
1601 	if (adt->histograms == NULL) {
1602 		int nr = evsel->evlist->core.nr_entries;
1603 
1604 		if (alloc_data_type_histograms(adt, nr) < 0)
1605 			return -1;
1606 	}
1607 
1608 	if (offset < 0 || offset >= adt->self.size)
1609 		return -1;
1610 
1611 	h = adt->histograms[evsel->core.idx];
1612 
1613 	h->nr_samples += nr_samples;
1614 	h->addr[offset].nr_samples += nr_samples;
1615 	h->period += period;
1616 	h->addr[offset].period += period;
1617 	return 0;
1618 }
1619 
1620 static void print_annotated_data_header(struct hist_entry *he, struct evsel *evsel)
1621 {
1622 	struct dso *dso = map__dso(he->ms.map);
1623 	int nr_members = 1;
1624 	int nr_samples = he->stat.nr_events;
1625 	int width = 7;
1626 	const char *val_hdr = "Percent";
1627 
1628 	if (evsel__is_group_event(evsel)) {
1629 		struct hist_entry *pair;
1630 
1631 		list_for_each_entry(pair, &he->pairs.head, pairs.node)
1632 			nr_samples += pair->stat.nr_events;
1633 	}
1634 
1635 	printf("Annotate type: '%s' in %s (%d samples):\n",
1636 	       he->mem_type->self.type_name, dso__name(dso), nr_samples);
1637 
1638 	if (evsel__is_group_event(evsel)) {
1639 		struct evsel *pos;
1640 		int i = 0;
1641 
1642 		nr_members = 0;
1643 		for_each_group_evsel(pos, evsel) {
1644 			if (symbol_conf.skip_empty &&
1645 			    evsel__hists(pos)->stats.nr_samples == 0)
1646 				continue;
1647 
1648 			printf(" event[%d] = %s\n", i++, pos->name);
1649 			nr_members++;
1650 		}
1651 	}
1652 
1653 	if (symbol_conf.show_total_period) {
1654 		width = 11;
1655 		val_hdr = "Period";
1656 	} else if (symbol_conf.show_nr_samples) {
1657 		width = 7;
1658 		val_hdr = "Samples";
1659 	}
1660 
1661 	printf("============================================================================\n");
1662 	printf("%*s %10s %10s  %s\n", (width + 1) * nr_members, val_hdr,
1663 	       "offset", "size", "field");
1664 }
1665 
1666 static void print_annotated_data_value(struct type_hist *h, u64 period, int nr_samples)
1667 {
1668 	double percent = h->period ? (100.0 * period / h->period) : 0;
1669 	const char *color = get_percent_color(percent);
1670 
1671 	if (symbol_conf.show_total_period)
1672 		color_fprintf(stdout, color, " %11" PRIu64, period);
1673 	else if (symbol_conf.show_nr_samples)
1674 		color_fprintf(stdout, color, " %7d", nr_samples);
1675 	else
1676 		color_fprintf(stdout, color, " %7.2f", percent);
1677 }
1678 
1679 static void print_annotated_data_type(struct annotated_data_type *mem_type,
1680 				      struct annotated_member *member,
1681 				      struct evsel *evsel, int indent)
1682 {
1683 	struct annotated_member *child;
1684 	struct type_hist *h = mem_type->histograms[evsel->core.idx];
1685 	int i, nr_events = 0, samples = 0;
1686 	u64 period = 0;
1687 	int width = symbol_conf.show_total_period ? 11 : 7;
1688 	struct evsel *pos;
1689 
1690 	for_each_group_evsel(pos, evsel) {
1691 		h = mem_type->histograms[pos->core.idx];
1692 
1693 		if (symbol_conf.skip_empty &&
1694 		    evsel__hists(pos)->stats.nr_samples == 0)
1695 			continue;
1696 
1697 		samples = 0;
1698 		period = 0;
1699 		for (i = 0; i < member->size; i++) {
1700 			samples += h->addr[member->offset + i].nr_samples;
1701 			period += h->addr[member->offset + i].period;
1702 		}
1703 		print_annotated_data_value(h, period, samples);
1704 		nr_events++;
1705 	}
1706 
1707 	printf(" %10d %10d  %*s%s\t%s",
1708 	       member->offset, member->size, indent, "", member->type_name,
1709 	       member->var_name ?: "");
1710 
1711 	if (!list_empty(&member->children))
1712 		printf(" {\n");
1713 
1714 	list_for_each_entry(child, &member->children, node)
1715 		print_annotated_data_type(mem_type, child, evsel, indent + 4);
1716 
1717 	if (!list_empty(&member->children))
1718 		printf("%*s}", (width + 1) * nr_events + 24 + indent, "");
1719 	printf(";\n");
1720 }
1721 
1722 int hist_entry__annotate_data_tty(struct hist_entry *he, struct evsel *evsel)
1723 {
1724 	print_annotated_data_header(he, evsel);
1725 	print_annotated_data_type(he->mem_type, &he->mem_type->self, evsel, 0);
1726 	printf("\n");
1727 
1728 	/* move to the next entry */
1729 	return '>';
1730 }
1731