xref: /linux/tools/perf/util/annotate-data.c (revision 922ec313f061cf75157d8e93fe16bc6397f6ea25)
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 /* returns if Type B has better information than Type A */
408 static bool is_better_type(Dwarf_Die *type_a, Dwarf_Die *type_b)
409 {
410 	Dwarf_Word size_a, size_b;
411 	Dwarf_Die die_a, die_b;
412 
413 	/* pointer type is preferred */
414 	if (is_pointer_type(type_a) != is_pointer_type(type_b))
415 		return is_pointer_type(type_b);
416 
417 	if (is_pointer_type(type_b)) {
418 		/*
419 		 * We want to compare the target type, but 'void *' can fail to
420 		 * get the target type.
421 		 */
422 		if (die_get_real_type(type_a, &die_a) == NULL)
423 			return true;
424 		if (die_get_real_type(type_b, &die_b) == NULL)
425 			return false;
426 
427 		type_a = &die_a;
428 		type_b = &die_b;
429 	}
430 
431 	/* bigger type is preferred */
432 	if (dwarf_aggregate_size(type_a, &size_a) < 0 ||
433 	    dwarf_aggregate_size(type_b, &size_b) < 0)
434 		return false;
435 
436 	return size_a < size_b;
437 }
438 
439 /* The type info will be saved in @type_die */
440 static enum type_match_result check_variable(struct data_loc_info *dloc,
441 					     Dwarf_Die *var_die,
442 					     Dwarf_Die *type_die, int reg,
443 					     int offset, bool is_fbreg)
444 {
445 	Dwarf_Word size;
446 	bool needs_pointer = true;
447 	Dwarf_Die sized_type;
448 
449 	if (reg == DWARF_REG_PC)
450 		needs_pointer = false;
451 	else if (reg == dloc->fbreg || is_fbreg)
452 		needs_pointer = false;
453 	else if (arch__is(dloc->arch, "x86") && reg == X86_REG_SP)
454 		needs_pointer = false;
455 
456 	/* Get the type of the variable */
457 	if (__die_get_real_type(var_die, type_die) == NULL)
458 		return PERF_TMR_NO_TYPE;
459 
460 	/*
461 	 * Usually it expects a pointer type for a memory access.
462 	 * Convert to a real type it points to.  But global variables
463 	 * and local variables are accessed directly without a pointer.
464 	 */
465 	if (needs_pointer) {
466 		if (!is_pointer_type(type_die) ||
467 		    __die_get_real_type(type_die, type_die) == NULL)
468 			return PERF_TMR_NO_POINTER;
469 	}
470 
471 	if (dwarf_tag(type_die) == DW_TAG_typedef)
472 		die_get_real_type(type_die, &sized_type);
473 	else
474 		sized_type = *type_die;
475 
476 	/* Get the size of the actual type */
477 	if (dwarf_aggregate_size(&sized_type, &size) < 0)
478 		return PERF_TMR_NO_SIZE;
479 
480 	/* Minimal sanity check */
481 	if ((unsigned)offset >= size)
482 		return PERF_TMR_BAD_OFFSET;
483 
484 	return PERF_TMR_OK;
485 }
486 
487 struct type_state_stack *find_stack_state(struct type_state *state,
488 						 int offset)
489 {
490 	struct type_state_stack *stack;
491 
492 	list_for_each_entry(stack, &state->stack_vars, list) {
493 		if (offset == stack->offset)
494 			return stack;
495 
496 		if (stack->compound && stack->offset < offset &&
497 		    offset < stack->offset + stack->size)
498 			return stack;
499 	}
500 	return NULL;
501 }
502 
503 void set_stack_state(struct type_state_stack *stack, int offset, u8 kind,
504 			    Dwarf_Die *type_die)
505 {
506 	int tag;
507 	Dwarf_Word size;
508 
509 	if (dwarf_aggregate_size(type_die, &size) < 0)
510 		size = 0;
511 
512 	tag = dwarf_tag(type_die);
513 
514 	stack->type = *type_die;
515 	stack->size = size;
516 	stack->offset = offset;
517 	stack->kind = kind;
518 
519 	switch (tag) {
520 	case DW_TAG_structure_type:
521 	case DW_TAG_union_type:
522 		stack->compound = (kind != TSR_KIND_POINTER);
523 		break;
524 	default:
525 		stack->compound = false;
526 		break;
527 	}
528 }
529 
530 struct type_state_stack *findnew_stack_state(struct type_state *state,
531 						    int offset, u8 kind,
532 						    Dwarf_Die *type_die)
533 {
534 	struct type_state_stack *stack = find_stack_state(state, offset);
535 
536 	if (stack) {
537 		set_stack_state(stack, offset, kind, type_die);
538 		return stack;
539 	}
540 
541 	stack = malloc(sizeof(*stack));
542 	if (stack) {
543 		set_stack_state(stack, offset, kind, type_die);
544 		list_add(&stack->list, &state->stack_vars);
545 	}
546 	return stack;
547 }
548 
549 /* Maintain a cache for quick global variable lookup */
550 struct global_var_entry {
551 	struct rb_node node;
552 	char *name;
553 	u64 start;
554 	u64 end;
555 	u64 die_offset;
556 };
557 
558 static int global_var_cmp(const void *_key, const struct rb_node *node)
559 {
560 	const u64 addr = (uintptr_t)_key;
561 	struct global_var_entry *gvar;
562 
563 	gvar = rb_entry(node, struct global_var_entry, node);
564 
565 	if (gvar->start <= addr && addr < gvar->end)
566 		return 0;
567 	return gvar->start > addr ? -1 : 1;
568 }
569 
570 static bool global_var_less(struct rb_node *node_a, const struct rb_node *node_b)
571 {
572 	struct global_var_entry *gvar_a, *gvar_b;
573 
574 	gvar_a = rb_entry(node_a, struct global_var_entry, node);
575 	gvar_b = rb_entry(node_b, struct global_var_entry, node);
576 
577 	return gvar_a->start < gvar_b->start;
578 }
579 
580 static struct global_var_entry *global_var__find(struct data_loc_info *dloc, u64 addr)
581 {
582 	struct dso *dso = map__dso(dloc->ms->map);
583 	struct rb_node *node;
584 
585 	node = rb_find((void *)(uintptr_t)addr, dso__global_vars(dso), global_var_cmp);
586 	if (node == NULL)
587 		return NULL;
588 
589 	return rb_entry(node, struct global_var_entry, node);
590 }
591 
592 static bool global_var__add(struct data_loc_info *dloc, u64 addr,
593 			    const char *name, Dwarf_Die *type_die)
594 {
595 	struct dso *dso = map__dso(dloc->ms->map);
596 	struct global_var_entry *gvar;
597 	Dwarf_Word size;
598 
599 	if (dwarf_aggregate_size(type_die, &size) < 0)
600 		return false;
601 
602 	gvar = malloc(sizeof(*gvar));
603 	if (gvar == NULL)
604 		return false;
605 
606 	gvar->name = name ? strdup(name) : NULL;
607 	if (name && gvar->name == NULL) {
608 		free(gvar);
609 		return false;
610 	}
611 
612 	gvar->start = addr;
613 	gvar->end = addr + size;
614 	gvar->die_offset = dwarf_dieoffset(type_die);
615 
616 	rb_add(&gvar->node, dso__global_vars(dso), global_var_less);
617 	return true;
618 }
619 
620 void global_var_type__tree_delete(struct rb_root *root)
621 {
622 	struct global_var_entry *gvar;
623 
624 	while (!RB_EMPTY_ROOT(root)) {
625 		struct rb_node *node = rb_first(root);
626 
627 		rb_erase(node, root);
628 		gvar = rb_entry(node, struct global_var_entry, node);
629 		zfree(&gvar->name);
630 		free(gvar);
631 	}
632 }
633 
634 bool get_global_var_info(struct data_loc_info *dloc, u64 addr,
635 				const char **var_name, int *var_offset)
636 {
637 	struct addr_location al;
638 	struct symbol *sym;
639 	u64 mem_addr;
640 
641 	/* Kernel symbols might be relocated */
642 	mem_addr = addr + map__reloc(dloc->ms->map);
643 
644 	addr_location__init(&al);
645 	sym = thread__find_symbol_fb(dloc->thread, dloc->cpumode,
646 				     mem_addr, &al);
647 	if (sym) {
648 		*var_name = sym->name;
649 		/* Calculate type offset from the start of variable */
650 		*var_offset = mem_addr - map__unmap_ip(al.map, sym->start);
651 	} else {
652 		*var_name = NULL;
653 	}
654 	addr_location__exit(&al);
655 	if (*var_name == NULL)
656 		return false;
657 
658 	return true;
659 }
660 
661 static void global_var__collect(struct data_loc_info *dloc)
662 {
663 	Dwarf *dwarf = dloc->di->dbg;
664 	Dwarf_Off off, next_off;
665 	Dwarf_Die cu_die, type_die;
666 	size_t header_size;
667 
668 	/* Iterate all CU and collect global variables that have no location in a register. */
669 	off = 0;
670 	while (dwarf_nextcu(dwarf, off, &next_off, &header_size,
671 			    NULL, NULL, NULL) == 0) {
672 		struct die_var_type *var_types = NULL;
673 		struct die_var_type *pos;
674 
675 		if (dwarf_offdie(dwarf, off + header_size, &cu_die) == NULL) {
676 			off = next_off;
677 			continue;
678 		}
679 
680 		die_collect_global_vars(&cu_die, &var_types);
681 
682 		for (pos = var_types; pos; pos = pos->next) {
683 			const char *var_name = NULL;
684 			int var_offset = 0;
685 
686 			if (pos->reg != -1)
687 				continue;
688 
689 			if (!dwarf_offdie(dwarf, pos->die_off, &type_die))
690 				continue;
691 
692 			if (!get_global_var_info(dloc, pos->addr, &var_name,
693 						 &var_offset))
694 				continue;
695 
696 			if (var_offset != 0)
697 				continue;
698 
699 			global_var__add(dloc, pos->addr, var_name, &type_die);
700 		}
701 
702 		delete_var_types(var_types);
703 
704 		off = next_off;
705 	}
706 }
707 
708 bool get_global_var_type(Dwarf_Die *cu_die, struct data_loc_info *dloc,
709 				u64 ip, u64 var_addr, int *var_offset,
710 				Dwarf_Die *type_die)
711 {
712 	u64 pc;
713 	int offset;
714 	const char *var_name = NULL;
715 	struct global_var_entry *gvar;
716 	struct dso *dso = map__dso(dloc->ms->map);
717 	Dwarf_Die var_die;
718 
719 	if (RB_EMPTY_ROOT(dso__global_vars(dso)))
720 		global_var__collect(dloc);
721 
722 	gvar = global_var__find(dloc, var_addr);
723 	if (gvar) {
724 		if (!dwarf_offdie(dloc->di->dbg, gvar->die_offset, type_die))
725 			return false;
726 
727 		*var_offset = var_addr - gvar->start;
728 		return true;
729 	}
730 
731 	/* Try to get the variable by address first */
732 	if (die_find_variable_by_addr(cu_die, var_addr, &var_die, &offset) &&
733 	    check_variable(dloc, &var_die, type_die, DWARF_REG_PC, offset,
734 			   /*is_fbreg=*/false) == PERF_TMR_OK) {
735 		var_name = dwarf_diename(&var_die);
736 		*var_offset = offset;
737 		goto ok;
738 	}
739 
740 	if (!get_global_var_info(dloc, var_addr, &var_name, var_offset))
741 		return false;
742 
743 	pc = map__rip_2objdump(dloc->ms->map, ip);
744 
745 	/* Try to get the name of global variable */
746 	if (die_find_variable_at(cu_die, var_name, pc, &var_die) &&
747 	    check_variable(dloc, &var_die, type_die, DWARF_REG_PC, *var_offset,
748 			   /*is_fbreg=*/false) == PERF_TMR_OK)
749 		goto ok;
750 
751 	return false;
752 
753 ok:
754 	/* The address should point to the start of the variable */
755 	global_var__add(dloc, var_addr - *var_offset, var_name, type_die);
756 	return true;
757 }
758 
759 /**
760  * update_var_state - Update type state using given variables
761  * @state: type state table
762  * @dloc: data location info
763  * @addr: instruction address to match with variable
764  * @insn_offset: instruction offset (for debug)
765  * @var_types: list of variables with type info
766  *
767  * This function fills the @state table using @var_types info.  Each variable
768  * is used only at the given location and updates an entry in the table.
769  */
770 static void update_var_state(struct type_state *state, struct data_loc_info *dloc,
771 			     u64 addr, u64 insn_offset, struct die_var_type *var_types)
772 {
773 	Dwarf_Die mem_die;
774 	struct die_var_type *var;
775 	int fbreg = dloc->fbreg;
776 	int fb_offset = 0;
777 
778 	if (dloc->fb_cfa) {
779 		if (die_get_cfa(dloc->di->dbg, addr, &fbreg, &fb_offset) < 0)
780 			fbreg = -1;
781 	}
782 
783 	for (var = var_types; var != NULL; var = var->next) {
784 		if (var->addr != addr)
785 			continue;
786 		/* Get the type DIE using the offset */
787 		if (!dwarf_offdie(dloc->di->dbg, var->die_off, &mem_die))
788 			continue;
789 
790 		if (var->reg == DWARF_REG_FB || var->reg == fbreg) {
791 			int offset = var->offset;
792 			struct type_state_stack *stack;
793 
794 			if (var->reg != DWARF_REG_FB)
795 				offset -= fb_offset;
796 
797 			stack = find_stack_state(state, offset);
798 			if (stack && stack->kind == TSR_KIND_TYPE &&
799 			    !is_better_type(&stack->type, &mem_die))
800 				continue;
801 
802 			findnew_stack_state(state, offset, TSR_KIND_TYPE,
803 					    &mem_die);
804 
805 			pr_debug_dtp("var [%"PRIx64"] -%#x(stack)",
806 				     insn_offset, -offset);
807 			pr_debug_type_name(&mem_die, TSR_KIND_TYPE);
808 		} else if (has_reg_type(state, var->reg) && var->offset == 0) {
809 			struct type_state_reg *reg;
810 
811 			reg = &state->regs[var->reg];
812 
813 			if (reg->ok && reg->kind == TSR_KIND_TYPE &&
814 			    !is_better_type(&reg->type, &mem_die))
815 				continue;
816 
817 			reg->type = mem_die;
818 			reg->kind = TSR_KIND_TYPE;
819 			reg->ok = true;
820 
821 			pr_debug_dtp("var [%"PRIx64"] reg%d",
822 				     insn_offset, var->reg);
823 			pr_debug_type_name(&mem_die, TSR_KIND_TYPE);
824 		}
825 	}
826 }
827 
828 /**
829  * update_insn_state - Update type state for an instruction
830  * @state: type state table
831  * @dloc: data location info
832  * @cu_die: compile unit debug entry
833  * @dl: disasm line for the instruction
834  *
835  * This function updates the @state table for the target operand of the
836  * instruction at @dl if it transfers the type like MOV on x86.  Since it
837  * tracks the type, it won't care about the values like in arithmetic
838  * instructions like ADD/SUB/MUL/DIV and INC/DEC.
839  *
840  * Note that ops->reg2 is only available when both mem_ref and multi_regs
841  * are true.
842  */
843 static void update_insn_state(struct type_state *state, struct data_loc_info *dloc,
844 			      Dwarf_Die *cu_die, struct disasm_line *dl)
845 {
846 	if (dloc->arch->update_insn_state)
847 		dloc->arch->update_insn_state(state, dloc, cu_die, dl);
848 }
849 
850 /*
851  * Prepend this_blocks (from the outer scope) to full_blocks, removing
852  * duplicate disasm line.
853  */
854 static void prepend_basic_blocks(struct list_head *this_blocks,
855 				 struct list_head *full_blocks)
856 {
857 	struct annotated_basic_block *first_bb, *last_bb;
858 
859 	last_bb = list_last_entry(this_blocks, typeof(*last_bb), list);
860 	first_bb = list_first_entry(full_blocks, typeof(*first_bb), list);
861 
862 	if (list_empty(full_blocks))
863 		goto out;
864 
865 	/* Last insn in this_blocks should be same as first insn in full_blocks */
866 	if (last_bb->end != first_bb->begin) {
867 		pr_debug("prepend basic blocks: mismatched disasm line %"PRIx64" -> %"PRIx64"\n",
868 			 last_bb->end->al.offset, first_bb->begin->al.offset);
869 		goto out;
870 	}
871 
872 	/* Is the basic block have only one disasm_line? */
873 	if (last_bb->begin == last_bb->end) {
874 		list_del(&last_bb->list);
875 		free(last_bb);
876 		goto out;
877 	}
878 
879 	/* Point to the insn before the last when adding this block to full_blocks */
880 	last_bb->end = list_prev_entry(last_bb->end, al.node);
881 
882 out:
883 	list_splice(this_blocks, full_blocks);
884 }
885 
886 static void delete_basic_blocks(struct list_head *basic_blocks)
887 {
888 	struct annotated_basic_block *bb, *tmp;
889 
890 	list_for_each_entry_safe(bb, tmp, basic_blocks, list) {
891 		list_del(&bb->list);
892 		free(bb);
893 	}
894 }
895 
896 /* Make sure all variables have a valid start address */
897 static void fixup_var_address(struct die_var_type *var_types, u64 addr)
898 {
899 	while (var_types) {
900 		/*
901 		 * Some variables have no address range meaning it's always
902 		 * available in the whole scope.  Let's adjust the start
903 		 * address to the start of the scope.
904 		 */
905 		if (var_types->addr == 0)
906 			var_types->addr = addr;
907 
908 		var_types = var_types->next;
909 	}
910 }
911 
912 static void delete_var_types(struct die_var_type *var_types)
913 {
914 	while (var_types) {
915 		struct die_var_type *next = var_types->next;
916 
917 		free(var_types);
918 		var_types = next;
919 	}
920 }
921 
922 /* should match to is_stack_canary() in util/annotate.c */
923 static void setup_stack_canary(struct data_loc_info *dloc)
924 {
925 	if (arch__is(dloc->arch, "x86")) {
926 		dloc->op->segment = INSN_SEG_X86_GS;
927 		dloc->op->imm = true;
928 		dloc->op->offset = 40;
929 	}
930 }
931 
932 /*
933  * It's at the target address, check if it has a matching type.
934  * It returns PERF_TMR_BAIL_OUT when it looks up per-cpu variables which
935  * are similar to global variables and no additional info is needed.
936  */
937 static enum type_match_result check_matching_type(struct type_state *state,
938 						  struct data_loc_info *dloc,
939 						  Dwarf_Die *cu_die,
940 						  Dwarf_Die *type_die)
941 {
942 	Dwarf_Word size;
943 	u32 insn_offset = dloc->ip - dloc->ms->sym->start;
944 	int reg = dloc->op->reg1;
945 
946 	pr_debug_dtp("chk [%x] reg%d offset=%#x ok=%d kind=%d ",
947 		     insn_offset, reg, dloc->op->offset,
948 		     state->regs[reg].ok, state->regs[reg].kind);
949 
950 	if (state->regs[reg].ok && state->regs[reg].kind == TSR_KIND_TYPE) {
951 		Dwarf_Die sized_type;
952 
953 		/*
954 		 * Normal registers should hold a pointer (or array) to
955 		 * dereference a memory location.
956 		 */
957 		if (!is_pointer_type(&state->regs[reg].type)) {
958 			if (dloc->op->offset < 0 && reg != state->stack_reg)
959 				goto check_kernel;
960 
961 			return PERF_TMR_NO_POINTER;
962 		}
963 
964 		/* Remove the pointer and get the target type */
965 		if (__die_get_real_type(&state->regs[reg].type, type_die) == NULL)
966 			return PERF_TMR_NO_POINTER;
967 
968 		dloc->type_offset = dloc->op->offset;
969 
970 		if (dwarf_tag(type_die) == DW_TAG_typedef)
971 			die_get_real_type(type_die, &sized_type);
972 		else
973 			sized_type = *type_die;
974 
975 		/* Get the size of the actual type */
976 		if (dwarf_aggregate_size(&sized_type, &size) < 0 ||
977 		    (unsigned)dloc->type_offset >= size)
978 			return PERF_TMR_BAD_OFFSET;
979 
980 		return PERF_TMR_OK;
981 	}
982 
983 	if (reg == dloc->fbreg) {
984 		struct type_state_stack *stack;
985 
986 		pr_debug_dtp("fbreg");
987 
988 		stack = find_stack_state(state, dloc->type_offset);
989 		if (stack == NULL)
990 			return PERF_TMR_NO_TYPE;
991 
992 		if (stack->kind == TSR_KIND_CANARY) {
993 			setup_stack_canary(dloc);
994 			return PERF_TMR_BAIL_OUT;
995 		}
996 
997 		if (stack->kind != TSR_KIND_TYPE)
998 			return PERF_TMR_NO_TYPE;
999 
1000 		*type_die = stack->type;
1001 		/* Update the type offset from the start of slot */
1002 		dloc->type_offset -= stack->offset;
1003 
1004 		return PERF_TMR_OK;
1005 	}
1006 
1007 	if (dloc->fb_cfa) {
1008 		struct type_state_stack *stack;
1009 		u64 pc = map__rip_2objdump(dloc->ms->map, dloc->ip);
1010 		int fbreg, fboff;
1011 
1012 		pr_debug_dtp("cfa");
1013 
1014 		if (die_get_cfa(dloc->di->dbg, pc, &fbreg, &fboff) < 0)
1015 			fbreg = -1;
1016 
1017 		if (reg != fbreg)
1018 			return PERF_TMR_NO_TYPE;
1019 
1020 		stack = find_stack_state(state, dloc->type_offset - fboff);
1021 		if (stack == NULL)
1022 			return PERF_TMR_NO_TYPE;
1023 
1024 		if (stack->kind == TSR_KIND_CANARY) {
1025 			setup_stack_canary(dloc);
1026 			return PERF_TMR_BAIL_OUT;
1027 		}
1028 
1029 		if (stack->kind != TSR_KIND_TYPE)
1030 			return PERF_TMR_NO_TYPE;
1031 
1032 		*type_die = stack->type;
1033 		/* Update the type offset from the start of slot */
1034 		dloc->type_offset -= fboff + stack->offset;
1035 
1036 		return PERF_TMR_OK;
1037 	}
1038 
1039 	if (state->regs[reg].kind == TSR_KIND_PERCPU_BASE) {
1040 		u64 var_addr = dloc->op->offset;
1041 		int var_offset;
1042 
1043 		pr_debug_dtp("percpu var");
1044 
1045 		if (dloc->op->multi_regs) {
1046 			int reg2 = dloc->op->reg2;
1047 
1048 			if (dloc->op->reg2 == reg)
1049 				reg2 = dloc->op->reg1;
1050 
1051 			if (has_reg_type(state, reg2) && state->regs[reg2].ok &&
1052 			    state->regs[reg2].kind == TSR_KIND_CONST)
1053 				var_addr += state->regs[reg2].imm_value;
1054 		}
1055 
1056 		if (get_global_var_type(cu_die, dloc, dloc->ip, var_addr,
1057 					&var_offset, type_die)) {
1058 			dloc->type_offset = var_offset;
1059 			return PERF_TMR_OK;
1060 		}
1061 		/* No need to retry per-cpu (global) variables */
1062 		return PERF_TMR_BAIL_OUT;
1063 	}
1064 
1065 	if (state->regs[reg].ok && state->regs[reg].kind == TSR_KIND_POINTER) {
1066 		pr_debug_dtp("percpu ptr");
1067 
1068 		/*
1069 		 * It's actaully pointer but the address was calculated using
1070 		 * some arithmetic.  So it points to the actual type already.
1071 		 */
1072 		*type_die = state->regs[reg].type;
1073 
1074 		dloc->type_offset = dloc->op->offset;
1075 
1076 		/* Get the size of the actual type */
1077 		if (dwarf_aggregate_size(type_die, &size) < 0 ||
1078 		    (unsigned)dloc->type_offset >= size)
1079 			return PERF_TMR_BAIL_OUT;
1080 
1081 		return PERF_TMR_OK;
1082 	}
1083 
1084 	if (state->regs[reg].ok && state->regs[reg].kind == TSR_KIND_CANARY) {
1085 		pr_debug_dtp("stack canary");
1086 
1087 		/*
1088 		 * This is a saved value of the stack canary which will be handled
1089 		 * in the outer logic when it returns failure here.  Pretend it's
1090 		 * from the stack canary directly.
1091 		 */
1092 		setup_stack_canary(dloc);
1093 
1094 		return PERF_TMR_BAIL_OUT;
1095 	}
1096 
1097 check_kernel:
1098 	if (dso__kernel(map__dso(dloc->ms->map))) {
1099 		u64 addr;
1100 		int offset;
1101 
1102 		/* Direct this-cpu access like "%gs:0x34740" */
1103 		if (dloc->op->segment == INSN_SEG_X86_GS && dloc->op->imm &&
1104 		    arch__is(dloc->arch, "x86")) {
1105 			pr_debug_dtp("this-cpu var");
1106 
1107 			addr = dloc->op->offset;
1108 
1109 			if (get_global_var_type(cu_die, dloc, dloc->ip, addr,
1110 						&offset, type_die)) {
1111 				dloc->type_offset = offset;
1112 				return PERF_TMR_OK;
1113 			}
1114 			return PERF_TMR_BAIL_OUT;
1115 		}
1116 
1117 		/* Access to global variable like "-0x7dcf0500(,%rdx,8)" */
1118 		if (dloc->op->offset < 0 && reg != state->stack_reg) {
1119 			addr = (s64) dloc->op->offset;
1120 
1121 			if (get_global_var_type(cu_die, dloc, dloc->ip, addr,
1122 						&offset, type_die)) {
1123 				pr_debug_dtp("global var");
1124 
1125 				dloc->type_offset = offset;
1126 				return PERF_TMR_OK;
1127 			}
1128 			return PERF_TMR_BAIL_OUT;
1129 		}
1130 	}
1131 
1132 	return PERF_TMR_UNKNOWN;
1133 }
1134 
1135 /* Iterate instructions in basic blocks and update type table */
1136 static enum type_match_result find_data_type_insn(struct data_loc_info *dloc,
1137 						  struct list_head *basic_blocks,
1138 						  struct die_var_type *var_types,
1139 						  Dwarf_Die *cu_die,
1140 						  Dwarf_Die *type_die)
1141 {
1142 	struct type_state state;
1143 	struct symbol *sym = dloc->ms->sym;
1144 	struct annotation *notes = symbol__annotation(sym);
1145 	struct annotated_basic_block *bb;
1146 	enum type_match_result ret = PERF_TMR_UNKNOWN;
1147 
1148 	init_type_state(&state, dloc->arch);
1149 
1150 	list_for_each_entry(bb, basic_blocks, list) {
1151 		struct disasm_line *dl = bb->begin;
1152 
1153 		BUG_ON(bb->begin->al.offset == -1 || bb->end->al.offset == -1);
1154 
1155 		pr_debug_dtp("bb: [%"PRIx64" - %"PRIx64"]\n",
1156 			     bb->begin->al.offset, bb->end->al.offset);
1157 
1158 		list_for_each_entry_from(dl, &notes->src->source, al.node) {
1159 			u64 this_ip = sym->start + dl->al.offset;
1160 			u64 addr = map__rip_2objdump(dloc->ms->map, this_ip);
1161 
1162 			/* Skip comment or debug info lines */
1163 			if (dl->al.offset == -1)
1164 				continue;
1165 
1166 			/* Update variable type at this address */
1167 			update_var_state(&state, dloc, addr, dl->al.offset, var_types);
1168 
1169 			if (this_ip == dloc->ip) {
1170 				ret = check_matching_type(&state, dloc,
1171 							  cu_die, type_die);
1172 				pr_debug_dtp(" : %s\n", match_result_str(ret));
1173 				goto out;
1174 			}
1175 
1176 			/* Update type table after processing the instruction */
1177 			update_insn_state(&state, dloc, cu_die, dl);
1178 			if (dl == bb->end)
1179 				break;
1180 		}
1181 	}
1182 
1183 out:
1184 	exit_type_state(&state);
1185 	return ret;
1186 }
1187 
1188 static int arch_supports_insn_tracking(struct data_loc_info *dloc)
1189 {
1190 	if ((arch__is(dloc->arch, "x86")) || (arch__is(dloc->arch, "powerpc")))
1191 		return 1;
1192 	return 0;
1193 }
1194 
1195 /*
1196  * Construct a list of basic blocks for each scope with variables and try to find
1197  * the data type by updating a type state table through instructions.
1198  */
1199 static enum type_match_result find_data_type_block(struct data_loc_info *dloc,
1200 						   Dwarf_Die *cu_die,
1201 						   Dwarf_Die *scopes,
1202 						   int nr_scopes,
1203 						   Dwarf_Die *type_die)
1204 {
1205 	LIST_HEAD(basic_blocks);
1206 	struct die_var_type *var_types = NULL;
1207 	u64 src_ip, dst_ip, prev_dst_ip;
1208 	enum type_match_result ret = PERF_TMR_UNKNOWN;
1209 
1210 	/* TODO: other architecture support */
1211 	if (!arch_supports_insn_tracking(dloc))
1212 		return PERF_TMR_BAIL_OUT;
1213 
1214 	prev_dst_ip = dst_ip = dloc->ip;
1215 	for (int i = nr_scopes - 1; i >= 0; i--) {
1216 		Dwarf_Addr base, start, end;
1217 		LIST_HEAD(this_blocks);
1218 
1219 		if (dwarf_ranges(&scopes[i], 0, &base, &start, &end) < 0)
1220 			break;
1221 
1222 		pr_debug_dtp("scope: [%d/%d] (die:%lx)\n",
1223 			     i + 1, nr_scopes, (long)dwarf_dieoffset(&scopes[i]));
1224 		src_ip = map__objdump_2rip(dloc->ms->map, start);
1225 
1226 again:
1227 		/* Get basic blocks for this scope */
1228 		if (annotate_get_basic_blocks(dloc->ms->sym, src_ip, dst_ip,
1229 					      &this_blocks) < 0) {
1230 			/* Try previous block if they are not connected */
1231 			if (prev_dst_ip != dst_ip) {
1232 				dst_ip = prev_dst_ip;
1233 				goto again;
1234 			}
1235 
1236 			pr_debug_dtp("cannot find a basic block from %"PRIx64" to %"PRIx64"\n",
1237 				     src_ip - dloc->ms->sym->start,
1238 				     dst_ip - dloc->ms->sym->start);
1239 			continue;
1240 		}
1241 		prepend_basic_blocks(&this_blocks, &basic_blocks);
1242 
1243 		/* Get variable info for this scope and add to var_types list */
1244 		die_collect_vars(&scopes[i], &var_types);
1245 		fixup_var_address(var_types, start);
1246 
1247 		/* Find from start of this scope to the target instruction */
1248 		ret = find_data_type_insn(dloc, &basic_blocks, var_types,
1249 					    cu_die, type_die);
1250 		if (ret == PERF_TMR_OK) {
1251 			char buf[64];
1252 
1253 			if (dloc->op->multi_regs)
1254 				snprintf(buf, sizeof(buf), "reg%d, reg%d",
1255 					 dloc->op->reg1, dloc->op->reg2);
1256 			else
1257 				snprintf(buf, sizeof(buf), "reg%d", dloc->op->reg1);
1258 
1259 			pr_debug_dtp("found by insn track: %#x(%s) type-offset=%#x\n",
1260 				     dloc->op->offset, buf, dloc->type_offset);
1261 			break;
1262 		}
1263 
1264 		if (ret == PERF_TMR_BAIL_OUT)
1265 			break;
1266 
1267 		/* Go up to the next scope and find blocks to the start */
1268 		prev_dst_ip = dst_ip;
1269 		dst_ip = src_ip;
1270 	}
1271 
1272 	delete_basic_blocks(&basic_blocks);
1273 	delete_var_types(var_types);
1274 	return ret;
1275 }
1276 
1277 /* The result will be saved in @type_die */
1278 static int find_data_type_die(struct data_loc_info *dloc, Dwarf_Die *type_die)
1279 {
1280 	struct annotated_op_loc *loc = dloc->op;
1281 	Dwarf_Die cu_die, var_die;
1282 	Dwarf_Die *scopes = NULL;
1283 	int reg, offset;
1284 	int ret = -1;
1285 	int i, nr_scopes;
1286 	int fbreg = -1;
1287 	int fb_offset = 0;
1288 	bool is_fbreg = false;
1289 	bool found = false;
1290 	u64 pc;
1291 	char buf[64];
1292 	enum type_match_result result = PERF_TMR_UNKNOWN;
1293 
1294 	if (dloc->op->multi_regs)
1295 		snprintf(buf, sizeof(buf), "reg%d, reg%d", dloc->op->reg1, dloc->op->reg2);
1296 	else if (dloc->op->reg1 == DWARF_REG_PC)
1297 		snprintf(buf, sizeof(buf), "PC");
1298 	else
1299 		snprintf(buf, sizeof(buf), "reg%d", dloc->op->reg1);
1300 
1301 	pr_debug_dtp("-----------------------------------------------------------\n");
1302 	pr_debug_dtp("find data type for %#x(%s) at %s+%#"PRIx64"\n",
1303 		     dloc->op->offset, buf, dloc->ms->sym->name,
1304 		     dloc->ip - dloc->ms->sym->start);
1305 
1306 	/*
1307 	 * IP is a relative instruction address from the start of the map, as
1308 	 * it can be randomized/relocated, it needs to translate to PC which is
1309 	 * a file address for DWARF processing.
1310 	 */
1311 	pc = map__rip_2objdump(dloc->ms->map, dloc->ip);
1312 
1313 	/* Get a compile_unit for this address */
1314 	if (!find_cu_die(dloc->di, pc, &cu_die)) {
1315 		pr_debug_dtp("cannot find CU for address %"PRIx64"\n", pc);
1316 		ann_data_stat.no_cuinfo++;
1317 		return -1;
1318 	}
1319 
1320 	reg = loc->reg1;
1321 	offset = loc->offset;
1322 
1323 	pr_debug_dtp("CU for %s (die:%#lx)\n",
1324 		     dwarf_diename(&cu_die), (long)dwarf_dieoffset(&cu_die));
1325 
1326 	if (reg == DWARF_REG_PC) {
1327 		if (get_global_var_type(&cu_die, dloc, dloc->ip, dloc->var_addr,
1328 					&offset, type_die)) {
1329 			dloc->type_offset = offset;
1330 
1331 			pr_debug_dtp("found by addr=%#"PRIx64" type_offset=%#x\n",
1332 				     dloc->var_addr, offset);
1333 			pr_debug_type_name(type_die, TSR_KIND_TYPE);
1334 			found = true;
1335 			goto out;
1336 		}
1337 	}
1338 
1339 	/* Get a list of nested scopes - i.e. (inlined) functions and blocks. */
1340 	nr_scopes = die_get_scopes(&cu_die, pc, &scopes);
1341 
1342 	if (reg != DWARF_REG_PC && dwarf_hasattr(&scopes[0], DW_AT_frame_base)) {
1343 		Dwarf_Attribute attr;
1344 		Dwarf_Block block;
1345 
1346 		/* Check if the 'reg' is assigned as frame base register */
1347 		if (dwarf_attr(&scopes[0], DW_AT_frame_base, &attr) != NULL &&
1348 		    dwarf_formblock(&attr, &block) == 0 && block.length == 1) {
1349 			switch (*block.data) {
1350 			case DW_OP_reg0 ... DW_OP_reg31:
1351 				fbreg = dloc->fbreg = *block.data - DW_OP_reg0;
1352 				break;
1353 			case DW_OP_call_frame_cfa:
1354 				dloc->fb_cfa = true;
1355 				if (die_get_cfa(dloc->di->dbg, pc, &fbreg,
1356 						&fb_offset) < 0)
1357 					fbreg = -1;
1358 				break;
1359 			default:
1360 				break;
1361 			}
1362 
1363 			pr_debug_dtp("frame base: cfa=%d fbreg=%d\n",
1364 				     dloc->fb_cfa, fbreg);
1365 		}
1366 	}
1367 
1368 retry:
1369 	is_fbreg = (reg == fbreg);
1370 	if (is_fbreg)
1371 		offset = loc->offset - fb_offset;
1372 
1373 	/* Search from the inner-most scope to the outer */
1374 	for (i = nr_scopes - 1; i >= 0; i--) {
1375 		Dwarf_Die mem_die;
1376 		int type_offset = offset;
1377 
1378 		if (reg == DWARF_REG_PC) {
1379 			if (!die_find_variable_by_addr(&scopes[i], dloc->var_addr,
1380 						       &var_die, &type_offset))
1381 				continue;
1382 		} else {
1383 			/* Look up variables/parameters in this scope */
1384 			if (!die_find_variable_by_reg(&scopes[i], pc, reg,
1385 						      &type_offset, is_fbreg, &var_die))
1386 				continue;
1387 		}
1388 
1389 		pr_debug_dtp("found \"%s\" (die: %#lx) in scope=%d/%d (die: %#lx) ",
1390 			     dwarf_diename(&var_die), (long)dwarf_dieoffset(&var_die),
1391 			     i+1, nr_scopes, (long)dwarf_dieoffset(&scopes[i]));
1392 
1393 		/* Found a variable, see if it's correct */
1394 		result = check_variable(dloc, &var_die, &mem_die, reg, type_offset, is_fbreg);
1395 		if (result == PERF_TMR_OK) {
1396 			if (reg == DWARF_REG_PC) {
1397 				pr_debug_dtp("addr=%#"PRIx64" type_offset=%#x\n",
1398 					     dloc->var_addr, type_offset);
1399 			} else if (reg == DWARF_REG_FB || is_fbreg) {
1400 				pr_debug_dtp("stack_offset=%#x type_offset=%#x\n",
1401 					     fb_offset, type_offset);
1402 			} else {
1403 				pr_debug_dtp("type_offset=%#x\n", type_offset);
1404 			}
1405 
1406 			if (!found || is_better_type(type_die, &mem_die)) {
1407 				*type_die = mem_die;
1408 				dloc->type_offset = type_offset;
1409 				found = true;
1410 			}
1411 		} else {
1412 			pr_debug_dtp("failed: %s\n", match_result_str(result));
1413 		}
1414 
1415 		pr_debug_location(&var_die, pc, reg);
1416 		pr_debug_type_name(&mem_die, TSR_KIND_TYPE);
1417 	}
1418 
1419 	if (!found && loc->multi_regs && reg == loc->reg1 && loc->reg1 != loc->reg2) {
1420 		reg = loc->reg2;
1421 		goto retry;
1422 	}
1423 
1424 	if (!found && reg != DWARF_REG_PC) {
1425 		result = find_data_type_block(dloc, &cu_die, scopes,
1426 					      nr_scopes, type_die);
1427 		if (result == PERF_TMR_OK) {
1428 			ann_data_stat.insn_track++;
1429 			found = true;
1430 		}
1431 	}
1432 
1433 out:
1434 	if (found) {
1435 		pr_debug_dtp("final type:");
1436 		pr_debug_type_name(type_die, TSR_KIND_TYPE);
1437 		ret = 0;
1438 	} else {
1439 		switch (result) {
1440 		case PERF_TMR_NO_TYPE:
1441 		case PERF_TMR_NO_POINTER:
1442 			pr_debug_dtp("%s\n", match_result_str(result));
1443 			ann_data_stat.no_typeinfo++;
1444 			break;
1445 		case PERF_TMR_NO_SIZE:
1446 			pr_debug_dtp("%s\n", match_result_str(result));
1447 			ann_data_stat.invalid_size++;
1448 			break;
1449 		case PERF_TMR_BAD_OFFSET:
1450 			pr_debug_dtp("%s\n", match_result_str(result));
1451 			ann_data_stat.bad_offset++;
1452 			break;
1453 		case PERF_TMR_UNKNOWN:
1454 		case PERF_TMR_BAIL_OUT:
1455 		case PERF_TMR_OK:  /* should not reach here */
1456 		default:
1457 			pr_debug_dtp("no variable found\n");
1458 			ann_data_stat.no_var++;
1459 			break;
1460 		}
1461 		ret = -1;
1462 	}
1463 
1464 	free(scopes);
1465 	return ret;
1466 }
1467 
1468 /**
1469  * find_data_type - Return a data type at the location
1470  * @dloc: data location
1471  *
1472  * This functions searches the debug information of the binary to get the data
1473  * type it accesses.  The exact location is expressed by (ip, reg, offset)
1474  * for pointer variables or (ip, addr) for global variables.  Note that global
1475  * variables might update the @dloc->type_offset after finding the start of the
1476  * variable.  If it cannot find a global variable by address, it tried to find
1477  * a declaration of the variable using var_name.  In that case, @dloc->offset
1478  * won't be updated.
1479  *
1480  * It return %NULL if not found.
1481  */
1482 struct annotated_data_type *find_data_type(struct data_loc_info *dloc)
1483 {
1484 	struct dso *dso = map__dso(dloc->ms->map);
1485 	Dwarf_Die type_die;
1486 
1487 	/*
1488 	 * The type offset is the same as instruction offset by default.
1489 	 * But when finding a global variable, the offset won't be valid.
1490 	 */
1491 	dloc->type_offset = dloc->op->offset;
1492 
1493 	dloc->fbreg = -1;
1494 
1495 	if (find_data_type_die(dloc, &type_die) < 0)
1496 		return NULL;
1497 
1498 	return dso__findnew_data_type(dso, &type_die);
1499 }
1500 
1501 static int alloc_data_type_histograms(struct annotated_data_type *adt, int nr_entries)
1502 {
1503 	int i;
1504 	size_t sz = sizeof(struct type_hist);
1505 
1506 	sz += sizeof(struct type_hist_entry) * adt->self.size;
1507 
1508 	/* Allocate a table of pointers for each event */
1509 	adt->histograms = calloc(nr_entries, sizeof(*adt->histograms));
1510 	if (adt->histograms == NULL)
1511 		return -ENOMEM;
1512 
1513 	/*
1514 	 * Each histogram is allocated for the whole size of the type.
1515 	 * TODO: Probably we can move the histogram to members.
1516 	 */
1517 	for (i = 0; i < nr_entries; i++) {
1518 		adt->histograms[i] = zalloc(sz);
1519 		if (adt->histograms[i] == NULL)
1520 			goto err;
1521 	}
1522 
1523 	adt->nr_histograms = nr_entries;
1524 	return 0;
1525 
1526 err:
1527 	while (--i >= 0)
1528 		zfree(&(adt->histograms[i]));
1529 	zfree(&adt->histograms);
1530 	return -ENOMEM;
1531 }
1532 
1533 static void delete_data_type_histograms(struct annotated_data_type *adt)
1534 {
1535 	for (int i = 0; i < adt->nr_histograms; i++)
1536 		zfree(&(adt->histograms[i]));
1537 
1538 	zfree(&adt->histograms);
1539 	adt->nr_histograms = 0;
1540 }
1541 
1542 void annotated_data_type__tree_delete(struct rb_root *root)
1543 {
1544 	struct annotated_data_type *pos;
1545 
1546 	while (!RB_EMPTY_ROOT(root)) {
1547 		struct rb_node *node = rb_first(root);
1548 
1549 		rb_erase(node, root);
1550 		pos = rb_entry(node, struct annotated_data_type, node);
1551 		delete_members(&pos->self);
1552 		delete_data_type_histograms(pos);
1553 		zfree(&pos->self.type_name);
1554 		free(pos);
1555 	}
1556 }
1557 
1558 /**
1559  * annotated_data_type__update_samples - Update histogram
1560  * @adt: Data type to update
1561  * @evsel: Event to update
1562  * @offset: Offset in the type
1563  * @nr_samples: Number of samples at this offset
1564  * @period: Event count at this offset
1565  *
1566  * This function updates type histogram at @ofs for @evsel.  Samples are
1567  * aggregated before calling this function so it can be called with more
1568  * than one samples at a certain offset.
1569  */
1570 int annotated_data_type__update_samples(struct annotated_data_type *adt,
1571 					struct evsel *evsel, int offset,
1572 					int nr_samples, u64 period)
1573 {
1574 	struct type_hist *h;
1575 
1576 	if (adt == NULL)
1577 		return 0;
1578 
1579 	if (adt->histograms == NULL) {
1580 		int nr = evsel->evlist->core.nr_entries;
1581 
1582 		if (alloc_data_type_histograms(adt, nr) < 0)
1583 			return -1;
1584 	}
1585 
1586 	if (offset < 0 || offset >= adt->self.size)
1587 		return -1;
1588 
1589 	h = adt->histograms[evsel->core.idx];
1590 
1591 	h->nr_samples += nr_samples;
1592 	h->addr[offset].nr_samples += nr_samples;
1593 	h->period += period;
1594 	h->addr[offset].period += period;
1595 	return 0;
1596 }
1597 
1598 static void print_annotated_data_header(struct hist_entry *he, struct evsel *evsel)
1599 {
1600 	struct dso *dso = map__dso(he->ms.map);
1601 	int nr_members = 1;
1602 	int nr_samples = he->stat.nr_events;
1603 	int width = 7;
1604 	const char *val_hdr = "Percent";
1605 
1606 	if (evsel__is_group_event(evsel)) {
1607 		struct hist_entry *pair;
1608 
1609 		list_for_each_entry(pair, &he->pairs.head, pairs.node)
1610 			nr_samples += pair->stat.nr_events;
1611 	}
1612 
1613 	printf("Annotate type: '%s' in %s (%d samples):\n",
1614 	       he->mem_type->self.type_name, dso__name(dso), nr_samples);
1615 
1616 	if (evsel__is_group_event(evsel)) {
1617 		struct evsel *pos;
1618 		int i = 0;
1619 
1620 		nr_members = 0;
1621 		for_each_group_evsel(pos, evsel) {
1622 			if (symbol_conf.skip_empty &&
1623 			    evsel__hists(pos)->stats.nr_samples == 0)
1624 				continue;
1625 
1626 			printf(" event[%d] = %s\n", i++, pos->name);
1627 			nr_members++;
1628 		}
1629 	}
1630 
1631 	if (symbol_conf.show_total_period) {
1632 		width = 11;
1633 		val_hdr = "Period";
1634 	} else if (symbol_conf.show_nr_samples) {
1635 		width = 7;
1636 		val_hdr = "Samples";
1637 	}
1638 
1639 	printf("============================================================================\n");
1640 	printf("%*s %10s %10s  %s\n", (width + 1) * nr_members, val_hdr,
1641 	       "offset", "size", "field");
1642 }
1643 
1644 static void print_annotated_data_value(struct type_hist *h, u64 period, int nr_samples)
1645 {
1646 	double percent = h->period ? (100.0 * period / h->period) : 0;
1647 	const char *color = get_percent_color(percent);
1648 
1649 	if (symbol_conf.show_total_period)
1650 		color_fprintf(stdout, color, " %11" PRIu64, period);
1651 	else if (symbol_conf.show_nr_samples)
1652 		color_fprintf(stdout, color, " %7d", nr_samples);
1653 	else
1654 		color_fprintf(stdout, color, " %7.2f", percent);
1655 }
1656 
1657 static void print_annotated_data_type(struct annotated_data_type *mem_type,
1658 				      struct annotated_member *member,
1659 				      struct evsel *evsel, int indent)
1660 {
1661 	struct annotated_member *child;
1662 	struct type_hist *h = mem_type->histograms[evsel->core.idx];
1663 	int i, nr_events = 0, samples = 0;
1664 	u64 period = 0;
1665 	int width = symbol_conf.show_total_period ? 11 : 7;
1666 	struct evsel *pos;
1667 
1668 	for_each_group_evsel(pos, evsel) {
1669 		h = mem_type->histograms[pos->core.idx];
1670 
1671 		if (symbol_conf.skip_empty &&
1672 		    evsel__hists(pos)->stats.nr_samples == 0)
1673 			continue;
1674 
1675 		samples = 0;
1676 		period = 0;
1677 		for (i = 0; i < member->size; i++) {
1678 			samples += h->addr[member->offset + i].nr_samples;
1679 			period += h->addr[member->offset + i].period;
1680 		}
1681 		print_annotated_data_value(h, period, samples);
1682 		nr_events++;
1683 	}
1684 
1685 	printf(" %10d %10d  %*s%s\t%s",
1686 	       member->offset, member->size, indent, "", member->type_name,
1687 	       member->var_name ?: "");
1688 
1689 	if (!list_empty(&member->children))
1690 		printf(" {\n");
1691 
1692 	list_for_each_entry(child, &member->children, node)
1693 		print_annotated_data_type(mem_type, child, evsel, indent + 4);
1694 
1695 	if (!list_empty(&member->children))
1696 		printf("%*s}", (width + 1) * nr_events + 24 + indent, "");
1697 	printf(";\n");
1698 }
1699 
1700 int hist_entry__annotate_data_tty(struct hist_entry *he, struct evsel *evsel)
1701 {
1702 	print_annotated_data_header(he, evsel);
1703 	print_annotated_data_type(he->mem_type, &he->mem_type->self, evsel, 0);
1704 	printf("\n");
1705 
1706 	/* move to the next entry */
1707 	return '>';
1708 }
1709