/* SPDX-License-Identifier: GPL-2.0 */ /* * Convert sample address to data type using DWARF debug info. * * Written by Namhyung Kim */ #include #include #include #include #include "annotate.h" #include "annotate-data.h" #include "debuginfo.h" #include "debug.h" #include "dso.h" #include "dwarf-regs.h" #include "evsel.h" #include "evlist.h" #include "map.h" #include "map_symbol.h" #include "sort.h" #include "strbuf.h" #include "symbol.h" #include "symbol_conf.h" #include "thread.h" /* register number of the stack pointer */ #define X86_REG_SP 7 static void delete_var_types(struct die_var_type *var_types); #define pr_debug_dtp(fmt, ...) \ do { \ if (debug_type_profile) \ pr_info(fmt, ##__VA_ARGS__); \ else \ pr_debug3(fmt, ##__VA_ARGS__); \ } while (0) void pr_debug_type_name(Dwarf_Die *die, enum type_state_kind kind) { struct strbuf sb; char *str; Dwarf_Word size = 0; if (!debug_type_profile && verbose < 3) return; switch (kind) { case TSR_KIND_INVALID: pr_info("\n"); return; case TSR_KIND_PERCPU_BASE: pr_info(" percpu base\n"); return; case TSR_KIND_CONST: pr_info(" constant\n"); return; case TSR_KIND_POINTER: pr_info(" pointer"); /* it also prints the type info */ break; case TSR_KIND_CANARY: pr_info(" stack canary\n"); return; case TSR_KIND_TYPE: default: break; } dwarf_aggregate_size(die, &size); strbuf_init(&sb, 32); die_get_typename_from_type(die, &sb); str = strbuf_detach(&sb, NULL); pr_info(" type='%s' size=%#lx (die:%#lx)\n", str, (long)size, (long)dwarf_dieoffset(die)); free(str); } static void pr_debug_location(Dwarf_Die *die, u64 pc, int reg) { ptrdiff_t off = 0; Dwarf_Attribute attr; Dwarf_Addr base, start, end; Dwarf_Op *ops; size_t nops; if (!debug_type_profile && verbose < 3) return; if (dwarf_attr(die, DW_AT_location, &attr) == NULL) return; while ((off = dwarf_getlocations(&attr, off, &base, &start, &end, &ops, &nops)) > 0) { if (reg != DWARF_REG_PC && end <= pc) continue; if (reg != DWARF_REG_PC && start > pc) break; pr_info(" variable location: "); switch (ops->atom) { case DW_OP_reg0 ...DW_OP_reg31: pr_info("reg%d\n", ops->atom - DW_OP_reg0); break; case DW_OP_breg0 ...DW_OP_breg31: pr_info("base=reg%d, offset=%#lx\n", ops->atom - DW_OP_breg0, (long)ops->number); break; case DW_OP_regx: pr_info("reg%ld\n", (long)ops->number); break; case DW_OP_bregx: pr_info("base=reg%ld, offset=%#lx\n", (long)ops->number, (long)ops->number2); break; case DW_OP_fbreg: pr_info("use frame base, offset=%#lx\n", (long)ops->number); break; case DW_OP_addr: pr_info("address=%#lx\n", (long)ops->number); break; default: pr_info("unknown: code=%#x, number=%#lx\n", ops->atom, (long)ops->number); break; } break; } } static void pr_debug_scope(Dwarf_Die *scope_die) { int tag; if (!debug_type_profile && verbose < 3) return; pr_info("(die:%lx) ", (long)dwarf_dieoffset(scope_die)); tag = dwarf_tag(scope_die); if (tag == DW_TAG_subprogram) pr_info("[function] %s\n", dwarf_diename(scope_die)); else if (tag == DW_TAG_inlined_subroutine) pr_info("[inlined] %s\n", dwarf_diename(scope_die)); else if (tag == DW_TAG_lexical_block) pr_info("[block]\n"); else pr_info("[unknown] tag=%x\n", tag); } bool has_reg_type(struct type_state *state, int reg) { return (unsigned)reg < ARRAY_SIZE(state->regs); } static void init_type_state(struct type_state *state, struct arch *arch) { memset(state, 0, sizeof(*state)); INIT_LIST_HEAD(&state->stack_vars); if (arch__is(arch, "x86")) { state->regs[0].caller_saved = true; state->regs[1].caller_saved = true; state->regs[2].caller_saved = true; state->regs[4].caller_saved = true; state->regs[5].caller_saved = true; state->regs[8].caller_saved = true; state->regs[9].caller_saved = true; state->regs[10].caller_saved = true; state->regs[11].caller_saved = true; state->ret_reg = 0; state->stack_reg = X86_REG_SP; } } static void exit_type_state(struct type_state *state) { struct type_state_stack *stack, *tmp; list_for_each_entry_safe(stack, tmp, &state->stack_vars, list) { list_del(&stack->list); free(stack); } } /* * Compare type name and size to maintain them in a tree. * I'm not sure if DWARF would have information of a single type in many * different places (compilation units). If not, it could compare the * offset of the type entry in the .debug_info section. */ static int data_type_cmp(const void *_key, const struct rb_node *node) { const struct annotated_data_type *key = _key; struct annotated_data_type *type; type = rb_entry(node, struct annotated_data_type, node); if (key->self.size != type->self.size) return key->self.size - type->self.size; return strcmp(key->self.type_name, type->self.type_name); } static bool data_type_less(struct rb_node *node_a, const struct rb_node *node_b) { struct annotated_data_type *a, *b; a = rb_entry(node_a, struct annotated_data_type, node); b = rb_entry(node_b, struct annotated_data_type, node); if (a->self.size != b->self.size) return a->self.size < b->self.size; return strcmp(a->self.type_name, b->self.type_name) < 0; } /* Recursively add new members for struct/union */ static int __add_member_cb(Dwarf_Die *die, void *arg) { struct annotated_member *parent = arg; struct annotated_member *member; Dwarf_Die member_type, die_mem; Dwarf_Word size, loc, bit_size = 0; Dwarf_Attribute attr; struct strbuf sb; int tag; if (dwarf_tag(die) != DW_TAG_member) return DIE_FIND_CB_SIBLING; member = zalloc(sizeof(*member)); if (member == NULL) return DIE_FIND_CB_END; strbuf_init(&sb, 32); die_get_typename(die, &sb); __die_get_real_type(die, &member_type); if (dwarf_tag(&member_type) == DW_TAG_typedef) die_get_real_type(&member_type, &die_mem); else die_mem = member_type; if (dwarf_aggregate_size(&die_mem, &size) < 0) size = 0; if (dwarf_attr_integrate(die, DW_AT_data_member_location, &attr)) dwarf_formudata(&attr, &loc); else { /* bitfield member */ if (dwarf_attr_integrate(die, DW_AT_data_bit_offset, &attr) && dwarf_formudata(&attr, &loc) == 0) loc /= 8; else loc = 0; if (dwarf_attr_integrate(die, DW_AT_bit_size, &attr) && dwarf_formudata(&attr, &bit_size) == 0) size = (bit_size + 7) / 8; } member->type_name = strbuf_detach(&sb, NULL); /* member->var_name can be NULL */ if (dwarf_diename(die)) { if (bit_size) { if (asprintf(&member->var_name, "%s:%ld", dwarf_diename(die), (long)bit_size) < 0) member->var_name = NULL; } else { member->var_name = strdup(dwarf_diename(die)); } if (member->var_name == NULL) { free(member); return DIE_FIND_CB_END; } } member->size = size; member->offset = loc + parent->offset; INIT_LIST_HEAD(&member->children); list_add_tail(&member->node, &parent->children); tag = dwarf_tag(&die_mem); switch (tag) { case DW_TAG_structure_type: case DW_TAG_union_type: die_find_child(&die_mem, __add_member_cb, member, &die_mem); break; default: break; } return DIE_FIND_CB_SIBLING; } static void add_member_types(struct annotated_data_type *parent, Dwarf_Die *type) { Dwarf_Die die_mem; die_find_child(type, __add_member_cb, &parent->self, &die_mem); } static void delete_members(struct annotated_member *member) { struct annotated_member *child, *tmp; list_for_each_entry_safe(child, tmp, &member->children, node) { list_del(&child->node); delete_members(child); zfree(&child->type_name); zfree(&child->var_name); free(child); } } static struct annotated_data_type *dso__findnew_data_type(struct dso *dso, Dwarf_Die *type_die) { struct annotated_data_type *result = NULL; struct annotated_data_type key; struct rb_node *node; struct strbuf sb; char *type_name; Dwarf_Word size; strbuf_init(&sb, 32); if (die_get_typename_from_type(type_die, &sb) < 0) strbuf_add(&sb, "(unknown type)", 14); type_name = strbuf_detach(&sb, NULL); if (dwarf_tag(type_die) == DW_TAG_typedef) die_get_real_type(type_die, type_die); dwarf_aggregate_size(type_die, &size); /* Check existing nodes in dso->data_types tree */ key.self.type_name = type_name; key.self.size = size; node = rb_find(&key, dso__data_types(dso), data_type_cmp); if (node) { result = rb_entry(node, struct annotated_data_type, node); free(type_name); return result; } /* If not, add a new one */ result = zalloc(sizeof(*result)); if (result == NULL) { free(type_name); return NULL; } result->self.type_name = type_name; result->self.size = size; INIT_LIST_HEAD(&result->self.children); if (symbol_conf.annotate_data_member) add_member_types(result, type_die); rb_add(&result->node, dso__data_types(dso), data_type_less); return result; } static bool find_cu_die(struct debuginfo *di, u64 pc, Dwarf_Die *cu_die) { Dwarf_Off off, next_off; size_t header_size; if (dwarf_addrdie(di->dbg, pc, cu_die) != NULL) return cu_die; /* * There are some kernels don't have full aranges and contain only a few * aranges entries. Fallback to iterate all CU entries in .debug_info * in case it's missing. */ off = 0; while (dwarf_nextcu(di->dbg, off, &next_off, &header_size, NULL, NULL, NULL) == 0) { if (dwarf_offdie(di->dbg, off + header_size, cu_die) && dwarf_haspc(cu_die, pc)) return true; off = next_off; } return false; } enum type_match_result { PERF_TMR_UNKNOWN = 0, PERF_TMR_OK, PERF_TMR_NO_TYPE, PERF_TMR_NO_POINTER, PERF_TMR_NO_SIZE, PERF_TMR_BAD_OFFSET, PERF_TMR_BAIL_OUT, }; static const char *match_result_str(enum type_match_result tmr) { switch (tmr) { case PERF_TMR_OK: return "Good!"; case PERF_TMR_NO_TYPE: return "no type information"; case PERF_TMR_NO_POINTER: return "no/void pointer"; case PERF_TMR_NO_SIZE: return "type size is unknown"; case PERF_TMR_BAD_OFFSET: return "offset bigger than size"; case PERF_TMR_UNKNOWN: case PERF_TMR_BAIL_OUT: default: return "invalid state"; } } static bool is_pointer_type(Dwarf_Die *type_die) { int tag = dwarf_tag(type_die); return tag == DW_TAG_pointer_type || tag == DW_TAG_array_type; } static bool is_compound_type(Dwarf_Die *type_die) { int tag = dwarf_tag(type_die); return tag == DW_TAG_structure_type || tag == DW_TAG_union_type; } /* returns if Type B has better information than Type A */ static bool is_better_type(Dwarf_Die *type_a, Dwarf_Die *type_b) { Dwarf_Word size_a, size_b; Dwarf_Die die_a, die_b; /* pointer type is preferred */ if (is_pointer_type(type_a) != is_pointer_type(type_b)) return is_pointer_type(type_b); if (is_pointer_type(type_b)) { /* * We want to compare the target type, but 'void *' can fail to * get the target type. */ if (die_get_real_type(type_a, &die_a) == NULL) return true; if (die_get_real_type(type_b, &die_b) == NULL) return false; type_a = &die_a; type_b = &die_b; } /* bigger type is preferred */ if (dwarf_aggregate_size(type_a, &size_a) < 0 || dwarf_aggregate_size(type_b, &size_b) < 0) return false; if (size_a != size_b) return size_a < size_b; /* struct or union is preferred */ if (is_compound_type(type_a) != is_compound_type(type_b)) return is_compound_type(type_b); /* typedef is preferred */ if (dwarf_tag(type_b) == DW_TAG_typedef) return true; return false; } /* The type info will be saved in @type_die */ static enum type_match_result check_variable(struct data_loc_info *dloc, Dwarf_Die *var_die, Dwarf_Die *type_die, int reg, int offset, bool is_fbreg) { Dwarf_Word size; bool needs_pointer = true; Dwarf_Die sized_type; if (reg == DWARF_REG_PC) needs_pointer = false; else if (reg == dloc->fbreg || is_fbreg) needs_pointer = false; else if (arch__is(dloc->arch, "x86") && reg == X86_REG_SP) needs_pointer = false; /* Get the type of the variable */ if (__die_get_real_type(var_die, type_die) == NULL) return PERF_TMR_NO_TYPE; /* * Usually it expects a pointer type for a memory access. * Convert to a real type it points to. But global variables * and local variables are accessed directly without a pointer. */ if (needs_pointer) { if (!is_pointer_type(type_die) || __die_get_real_type(type_die, type_die) == NULL) return PERF_TMR_NO_POINTER; } if (dwarf_tag(type_die) == DW_TAG_typedef) die_get_real_type(type_die, &sized_type); else sized_type = *type_die; /* Get the size of the actual type */ if (dwarf_aggregate_size(&sized_type, &size) < 0) return PERF_TMR_NO_SIZE; /* Minimal sanity check */ if ((unsigned)offset >= size) return PERF_TMR_BAD_OFFSET; return PERF_TMR_OK; } struct type_state_stack *find_stack_state(struct type_state *state, int offset) { struct type_state_stack *stack; list_for_each_entry(stack, &state->stack_vars, list) { if (offset == stack->offset) return stack; if (stack->compound && stack->offset < offset && offset < stack->offset + stack->size) return stack; } return NULL; } void set_stack_state(struct type_state_stack *stack, int offset, u8 kind, Dwarf_Die *type_die) { int tag; Dwarf_Word size; if (dwarf_aggregate_size(type_die, &size) < 0) size = 0; tag = dwarf_tag(type_die); stack->type = *type_die; stack->size = size; stack->offset = offset; stack->kind = kind; switch (tag) { case DW_TAG_structure_type: case DW_TAG_union_type: stack->compound = (kind != TSR_KIND_POINTER); break; default: stack->compound = false; break; } } struct type_state_stack *findnew_stack_state(struct type_state *state, int offset, u8 kind, Dwarf_Die *type_die) { struct type_state_stack *stack = find_stack_state(state, offset); if (stack) { set_stack_state(stack, offset, kind, type_die); return stack; } stack = malloc(sizeof(*stack)); if (stack) { set_stack_state(stack, offset, kind, type_die); list_add(&stack->list, &state->stack_vars); } return stack; } /* Maintain a cache for quick global variable lookup */ struct global_var_entry { struct rb_node node; char *name; u64 start; u64 end; u64 die_offset; }; static int global_var_cmp(const void *_key, const struct rb_node *node) { const u64 addr = (uintptr_t)_key; struct global_var_entry *gvar; gvar = rb_entry(node, struct global_var_entry, node); if (gvar->start <= addr && addr < gvar->end) return 0; return gvar->start > addr ? -1 : 1; } static bool global_var_less(struct rb_node *node_a, const struct rb_node *node_b) { struct global_var_entry *gvar_a, *gvar_b; gvar_a = rb_entry(node_a, struct global_var_entry, node); gvar_b = rb_entry(node_b, struct global_var_entry, node); return gvar_a->start < gvar_b->start; } static struct global_var_entry *global_var__find(struct data_loc_info *dloc, u64 addr) { struct dso *dso = map__dso(dloc->ms->map); struct rb_node *node; node = rb_find((void *)(uintptr_t)addr, dso__global_vars(dso), global_var_cmp); if (node == NULL) return NULL; return rb_entry(node, struct global_var_entry, node); } static bool global_var__add(struct data_loc_info *dloc, u64 addr, const char *name, Dwarf_Die *type_die) { struct dso *dso = map__dso(dloc->ms->map); struct global_var_entry *gvar; Dwarf_Word size; if (dwarf_aggregate_size(type_die, &size) < 0) return false; gvar = malloc(sizeof(*gvar)); if (gvar == NULL) return false; gvar->name = name ? strdup(name) : NULL; if (name && gvar->name == NULL) { free(gvar); return false; } gvar->start = addr; gvar->end = addr + size; gvar->die_offset = dwarf_dieoffset(type_die); rb_add(&gvar->node, dso__global_vars(dso), global_var_less); return true; } void global_var_type__tree_delete(struct rb_root *root) { struct global_var_entry *gvar; while (!RB_EMPTY_ROOT(root)) { struct rb_node *node = rb_first(root); rb_erase(node, root); gvar = rb_entry(node, struct global_var_entry, node); zfree(&gvar->name); free(gvar); } } bool get_global_var_info(struct data_loc_info *dloc, u64 addr, const char **var_name, int *var_offset) { struct addr_location al; struct symbol *sym; u64 mem_addr; /* Kernel symbols might be relocated */ mem_addr = addr + map__reloc(dloc->ms->map); addr_location__init(&al); sym = thread__find_symbol_fb(dloc->thread, dloc->cpumode, mem_addr, &al); if (sym) { *var_name = sym->name; /* Calculate type offset from the start of variable */ *var_offset = mem_addr - map__unmap_ip(al.map, sym->start); } else { *var_name = NULL; } addr_location__exit(&al); if (*var_name == NULL) return false; return true; } static void global_var__collect(struct data_loc_info *dloc) { Dwarf *dwarf = dloc->di->dbg; Dwarf_Off off, next_off; Dwarf_Die cu_die, type_die; size_t header_size; /* Iterate all CU and collect global variables that have no location in a register. */ off = 0; while (dwarf_nextcu(dwarf, off, &next_off, &header_size, NULL, NULL, NULL) == 0) { struct die_var_type *var_types = NULL; struct die_var_type *pos; if (dwarf_offdie(dwarf, off + header_size, &cu_die) == NULL) { off = next_off; continue; } die_collect_global_vars(&cu_die, &var_types); for (pos = var_types; pos; pos = pos->next) { const char *var_name = NULL; int var_offset = 0; if (pos->reg != -1) continue; if (!dwarf_offdie(dwarf, pos->die_off, &type_die)) continue; if (!get_global_var_info(dloc, pos->addr, &var_name, &var_offset)) continue; if (var_offset != 0) continue; global_var__add(dloc, pos->addr, var_name, &type_die); } delete_var_types(var_types); off = next_off; } } bool get_global_var_type(Dwarf_Die *cu_die, struct data_loc_info *dloc, u64 ip, u64 var_addr, int *var_offset, Dwarf_Die *type_die) { u64 pc; int offset; const char *var_name = NULL; struct global_var_entry *gvar; struct dso *dso = map__dso(dloc->ms->map); Dwarf_Die var_die; if (RB_EMPTY_ROOT(dso__global_vars(dso))) global_var__collect(dloc); gvar = global_var__find(dloc, var_addr); if (gvar) { if (!dwarf_offdie(dloc->di->dbg, gvar->die_offset, type_die)) return false; *var_offset = var_addr - gvar->start; return true; } /* Try to get the variable by address first */ if (die_find_variable_by_addr(cu_die, var_addr, &var_die, &offset) && check_variable(dloc, &var_die, type_die, DWARF_REG_PC, offset, /*is_fbreg=*/false) == PERF_TMR_OK) { var_name = dwarf_diename(&var_die); *var_offset = offset; goto ok; } if (!get_global_var_info(dloc, var_addr, &var_name, var_offset)) return false; pc = map__rip_2objdump(dloc->ms->map, ip); /* Try to get the name of global variable */ if (die_find_variable_at(cu_die, var_name, pc, &var_die) && check_variable(dloc, &var_die, type_die, DWARF_REG_PC, *var_offset, /*is_fbreg=*/false) == PERF_TMR_OK) goto ok; return false; ok: /* The address should point to the start of the variable */ global_var__add(dloc, var_addr - *var_offset, var_name, type_die); return true; } static bool die_is_same(Dwarf_Die *die_a, Dwarf_Die *die_b) { return (die_a->cu == die_b->cu) && (die_a->addr == die_b->addr); } /** * update_var_state - Update type state using given variables * @state: type state table * @dloc: data location info * @addr: instruction address to match with variable * @insn_offset: instruction offset (for debug) * @var_types: list of variables with type info * * This function fills the @state table using @var_types info. Each variable * is used only at the given location and updates an entry in the table. */ static void update_var_state(struct type_state *state, struct data_loc_info *dloc, u64 addr, u64 insn_offset, struct die_var_type *var_types) { Dwarf_Die mem_die; struct die_var_type *var; int fbreg = dloc->fbreg; int fb_offset = 0; if (dloc->fb_cfa) { if (die_get_cfa(dloc->di->dbg, addr, &fbreg, &fb_offset) < 0) fbreg = -1; } for (var = var_types; var != NULL; var = var->next) { if (var->addr != addr) continue; /* Get the type DIE using the offset */ if (!dwarf_offdie(dloc->di->dbg, var->die_off, &mem_die)) continue; if (var->reg == DWARF_REG_FB || var->reg == fbreg) { int offset = var->offset; struct type_state_stack *stack; if (var->reg != DWARF_REG_FB) offset -= fb_offset; stack = find_stack_state(state, offset); if (stack && stack->kind == TSR_KIND_TYPE && !is_better_type(&stack->type, &mem_die)) continue; findnew_stack_state(state, offset, TSR_KIND_TYPE, &mem_die); pr_debug_dtp("var [%"PRIx64"] -%#x(stack)", insn_offset, -offset); pr_debug_type_name(&mem_die, TSR_KIND_TYPE); } else if (has_reg_type(state, var->reg) && var->offset == 0) { struct type_state_reg *reg; Dwarf_Die orig_type; reg = &state->regs[var->reg]; if (reg->ok && reg->kind == TSR_KIND_TYPE && !is_better_type(®->type, &mem_die)) continue; orig_type = reg->type; reg->type = mem_die; reg->kind = TSR_KIND_TYPE; reg->ok = true; pr_debug_dtp("var [%"PRIx64"] reg%d", insn_offset, var->reg); pr_debug_type_name(&mem_die, TSR_KIND_TYPE); /* * If this register is directly copied from another and it gets a * better type, also update the type of the source register. This * is usually the case of container_of() macro with offset of 0. */ if (has_reg_type(state, reg->copied_from)) { struct type_state_reg *copy_reg; copy_reg = &state->regs[reg->copied_from]; /* TODO: check if type is compatible or embedded */ if (!copy_reg->ok || (copy_reg->kind != TSR_KIND_TYPE) || !die_is_same(©_reg->type, &orig_type) || !is_better_type(©_reg->type, &mem_die)) continue; copy_reg->type = mem_die; pr_debug_dtp("var [%"PRIx64"] copyback reg%d", insn_offset, reg->copied_from); pr_debug_type_name(&mem_die, TSR_KIND_TYPE); } } } } /** * update_insn_state - Update type state for an instruction * @state: type state table * @dloc: data location info * @cu_die: compile unit debug entry * @dl: disasm line for the instruction * * This function updates the @state table for the target operand of the * instruction at @dl if it transfers the type like MOV on x86. Since it * tracks the type, it won't care about the values like in arithmetic * instructions like ADD/SUB/MUL/DIV and INC/DEC. * * Note that ops->reg2 is only available when both mem_ref and multi_regs * are true. */ static void update_insn_state(struct type_state *state, struct data_loc_info *dloc, Dwarf_Die *cu_die, struct disasm_line *dl) { if (dloc->arch->update_insn_state) dloc->arch->update_insn_state(state, dloc, cu_die, dl); } /* * Prepend this_blocks (from the outer scope) to full_blocks, removing * duplicate disasm line. */ static void prepend_basic_blocks(struct list_head *this_blocks, struct list_head *full_blocks) { struct annotated_basic_block *first_bb, *last_bb; last_bb = list_last_entry(this_blocks, typeof(*last_bb), list); first_bb = list_first_entry(full_blocks, typeof(*first_bb), list); if (list_empty(full_blocks)) goto out; /* Last insn in this_blocks should be same as first insn in full_blocks */ if (last_bb->end != first_bb->begin) { pr_debug("prepend basic blocks: mismatched disasm line %"PRIx64" -> %"PRIx64"\n", last_bb->end->al.offset, first_bb->begin->al.offset); goto out; } /* Is the basic block have only one disasm_line? */ if (last_bb->begin == last_bb->end) { list_del(&last_bb->list); free(last_bb); goto out; } /* Point to the insn before the last when adding this block to full_blocks */ last_bb->end = list_prev_entry(last_bb->end, al.node); out: list_splice(this_blocks, full_blocks); } static void delete_basic_blocks(struct list_head *basic_blocks) { struct annotated_basic_block *bb, *tmp; list_for_each_entry_safe(bb, tmp, basic_blocks, list) { list_del(&bb->list); free(bb); } } /* Make sure all variables have a valid start address */ static void fixup_var_address(struct die_var_type *var_types, u64 addr) { while (var_types) { /* * Some variables have no address range meaning it's always * available in the whole scope. Let's adjust the start * address to the start of the scope. */ if (var_types->addr == 0) var_types->addr = addr; var_types = var_types->next; } } static void delete_var_types(struct die_var_type *var_types) { while (var_types) { struct die_var_type *next = var_types->next; free(var_types); var_types = next; } } /* should match to is_stack_canary() in util/annotate.c */ static void setup_stack_canary(struct data_loc_info *dloc) { if (arch__is(dloc->arch, "x86")) { dloc->op->segment = INSN_SEG_X86_GS; dloc->op->imm = true; dloc->op->offset = 40; } } /* * It's at the target address, check if it has a matching type. * It returns PERF_TMR_BAIL_OUT when it looks up per-cpu variables which * are similar to global variables and no additional info is needed. */ static enum type_match_result check_matching_type(struct type_state *state, struct data_loc_info *dloc, Dwarf_Die *cu_die, struct disasm_line *dl, Dwarf_Die *type_die) { Dwarf_Word size; u32 insn_offset = dl->al.offset; int reg = dloc->op->reg1; int offset = dloc->op->offset; const char *offset_sign = ""; bool retry = true; if (offset < 0) { offset = -offset; offset_sign = "-"; } again: pr_debug_dtp("chk [%x] reg%d offset=%s%#x ok=%d kind=%d ", insn_offset, reg, offset_sign, offset, state->regs[reg].ok, state->regs[reg].kind); if (!state->regs[reg].ok) goto check_non_register; if (state->regs[reg].kind == TSR_KIND_TYPE) { Dwarf_Die sized_type; struct strbuf sb; strbuf_init(&sb, 32); die_get_typename_from_type(&state->regs[reg].type, &sb); pr_debug_dtp("(%s)", sb.buf); strbuf_release(&sb); /* * Normal registers should hold a pointer (or array) to * dereference a memory location. */ if (!is_pointer_type(&state->regs[reg].type)) { if (dloc->op->offset < 0 && reg != state->stack_reg) goto check_kernel; return PERF_TMR_NO_POINTER; } /* Remove the pointer and get the target type */ if (__die_get_real_type(&state->regs[reg].type, type_die) == NULL) return PERF_TMR_NO_POINTER; dloc->type_offset = dloc->op->offset; if (dwarf_tag(type_die) == DW_TAG_typedef) die_get_real_type(type_die, &sized_type); else sized_type = *type_die; /* Get the size of the actual type */ if (dwarf_aggregate_size(&sized_type, &size) < 0 || (unsigned)dloc->type_offset >= size) return PERF_TMR_BAD_OFFSET; return PERF_TMR_OK; } if (state->regs[reg].kind == TSR_KIND_POINTER) { pr_debug_dtp("percpu ptr"); /* * It's actaully pointer but the address was calculated using * some arithmetic. So it points to the actual type already. */ *type_die = state->regs[reg].type; dloc->type_offset = dloc->op->offset; /* Get the size of the actual type */ if (dwarf_aggregate_size(type_die, &size) < 0 || (unsigned)dloc->type_offset >= size) return PERF_TMR_BAIL_OUT; return PERF_TMR_OK; } if (state->regs[reg].kind == TSR_KIND_CANARY) { pr_debug_dtp("stack canary"); /* * This is a saved value of the stack canary which will be handled * in the outer logic when it returns failure here. Pretend it's * from the stack canary directly. */ setup_stack_canary(dloc); return PERF_TMR_BAIL_OUT; } if (state->regs[reg].kind == TSR_KIND_PERCPU_BASE) { u64 var_addr = dloc->op->offset; int var_offset; pr_debug_dtp("percpu var"); if (dloc->op->multi_regs) { int reg2 = dloc->op->reg2; if (dloc->op->reg2 == reg) reg2 = dloc->op->reg1; if (has_reg_type(state, reg2) && state->regs[reg2].ok && state->regs[reg2].kind == TSR_KIND_CONST) var_addr += state->regs[reg2].imm_value; } if (get_global_var_type(cu_die, dloc, dloc->ip, var_addr, &var_offset, type_die)) { dloc->type_offset = var_offset; return PERF_TMR_OK; } /* No need to retry per-cpu (global) variables */ return PERF_TMR_BAIL_OUT; } check_non_register: if (reg == dloc->fbreg) { struct type_state_stack *stack; pr_debug_dtp("fbreg"); stack = find_stack_state(state, dloc->type_offset); if (stack == NULL) { if (retry) { pr_debug_dtp(" : retry\n"); retry = false; /* update type info it's the first store to the stack */ update_insn_state(state, dloc, cu_die, dl); goto again; } return PERF_TMR_NO_TYPE; } if (stack->kind == TSR_KIND_CANARY) { setup_stack_canary(dloc); return PERF_TMR_BAIL_OUT; } if (stack->kind != TSR_KIND_TYPE) return PERF_TMR_NO_TYPE; *type_die = stack->type; /* Update the type offset from the start of slot */ dloc->type_offset -= stack->offset; return PERF_TMR_OK; } if (dloc->fb_cfa) { struct type_state_stack *stack; u64 pc = map__rip_2objdump(dloc->ms->map, dloc->ip); int fbreg, fboff; pr_debug_dtp("cfa"); if (die_get_cfa(dloc->di->dbg, pc, &fbreg, &fboff) < 0) fbreg = -1; if (reg != fbreg) return PERF_TMR_NO_TYPE; stack = find_stack_state(state, dloc->type_offset - fboff); if (stack == NULL) { if (retry) { pr_debug_dtp(" : retry\n"); retry = false; /* update type info it's the first store to the stack */ update_insn_state(state, dloc, cu_die, dl); goto again; } return PERF_TMR_NO_TYPE; } if (stack->kind == TSR_KIND_CANARY) { setup_stack_canary(dloc); return PERF_TMR_BAIL_OUT; } if (stack->kind != TSR_KIND_TYPE) return PERF_TMR_NO_TYPE; *type_die = stack->type; /* Update the type offset from the start of slot */ dloc->type_offset -= fboff + stack->offset; return PERF_TMR_OK; } check_kernel: if (dso__kernel(map__dso(dloc->ms->map))) { u64 addr; /* Direct this-cpu access like "%gs:0x34740" */ if (dloc->op->segment == INSN_SEG_X86_GS && dloc->op->imm && arch__is(dloc->arch, "x86")) { pr_debug_dtp("this-cpu var"); addr = dloc->op->offset; if (get_global_var_type(cu_die, dloc, dloc->ip, addr, &offset, type_die)) { dloc->type_offset = offset; return PERF_TMR_OK; } return PERF_TMR_BAIL_OUT; } /* Access to global variable like "-0x7dcf0500(,%rdx,8)" */ if (dloc->op->offset < 0 && reg != state->stack_reg) { addr = (s64) dloc->op->offset; if (get_global_var_type(cu_die, dloc, dloc->ip, addr, &offset, type_die)) { pr_debug_dtp("global var"); dloc->type_offset = offset; return PERF_TMR_OK; } return PERF_TMR_BAIL_OUT; } } return PERF_TMR_UNKNOWN; } /* Iterate instructions in basic blocks and update type table */ static enum type_match_result find_data_type_insn(struct data_loc_info *dloc, struct list_head *basic_blocks, struct die_var_type *var_types, Dwarf_Die *cu_die, Dwarf_Die *type_die) { struct type_state state; struct symbol *sym = dloc->ms->sym; struct annotation *notes = symbol__annotation(sym); struct annotated_basic_block *bb; enum type_match_result ret = PERF_TMR_UNKNOWN; init_type_state(&state, dloc->arch); list_for_each_entry(bb, basic_blocks, list) { struct disasm_line *dl = bb->begin; BUG_ON(bb->begin->al.offset == -1 || bb->end->al.offset == -1); pr_debug_dtp("bb: [%"PRIx64" - %"PRIx64"]\n", bb->begin->al.offset, bb->end->al.offset); list_for_each_entry_from(dl, ¬es->src->source, al.node) { u64 this_ip = sym->start + dl->al.offset; u64 addr = map__rip_2objdump(dloc->ms->map, this_ip); /* Skip comment or debug info lines */ if (dl->al.offset == -1) continue; /* Update variable type at this address */ update_var_state(&state, dloc, addr, dl->al.offset, var_types); if (this_ip == dloc->ip) { ret = check_matching_type(&state, dloc, cu_die, dl, type_die); pr_debug_dtp(" : %s\n", match_result_str(ret)); goto out; } /* Update type table after processing the instruction */ update_insn_state(&state, dloc, cu_die, dl); if (dl == bb->end) break; } } out: exit_type_state(&state); return ret; } static int arch_supports_insn_tracking(struct data_loc_info *dloc) { if ((arch__is(dloc->arch, "x86")) || (arch__is(dloc->arch, "powerpc"))) return 1; return 0; } /* * Construct a list of basic blocks for each scope with variables and try to find * the data type by updating a type state table through instructions. */ static enum type_match_result find_data_type_block(struct data_loc_info *dloc, Dwarf_Die *cu_die, Dwarf_Die *scopes, int nr_scopes, Dwarf_Die *type_die) { LIST_HEAD(basic_blocks); struct die_var_type *var_types = NULL; u64 src_ip, dst_ip, prev_dst_ip; enum type_match_result ret = PERF_TMR_UNKNOWN; /* TODO: other architecture support */ if (!arch_supports_insn_tracking(dloc)) return PERF_TMR_BAIL_OUT; prev_dst_ip = dst_ip = dloc->ip; for (int i = nr_scopes - 1; i >= 0; i--) { Dwarf_Addr base, start, end; LIST_HEAD(this_blocks); if (dwarf_ranges(&scopes[i], 0, &base, &start, &end) < 0) break; pr_debug_dtp("scope: [%d/%d] ", i + 1, nr_scopes); pr_debug_scope(&scopes[i]); src_ip = map__objdump_2rip(dloc->ms->map, start); again: /* Get basic blocks for this scope */ if (annotate_get_basic_blocks(dloc->ms->sym, src_ip, dst_ip, &this_blocks) < 0) { /* Try previous block if they are not connected */ if (prev_dst_ip != dst_ip) { dst_ip = prev_dst_ip; goto again; } pr_debug_dtp("cannot find a basic block from %"PRIx64" to %"PRIx64"\n", src_ip - dloc->ms->sym->start, dst_ip - dloc->ms->sym->start); continue; } prepend_basic_blocks(&this_blocks, &basic_blocks); /* Get variable info for this scope and add to var_types list */ die_collect_vars(&scopes[i], &var_types); fixup_var_address(var_types, start); /* Find from start of this scope to the target instruction */ ret = find_data_type_insn(dloc, &basic_blocks, var_types, cu_die, type_die); if (ret == PERF_TMR_OK) { char buf[64]; int offset = dloc->op->offset; const char *offset_sign = ""; if (offset < 0) { offset = -offset; offset_sign = "-"; } if (dloc->op->multi_regs) snprintf(buf, sizeof(buf), "reg%d, reg%d", dloc->op->reg1, dloc->op->reg2); else snprintf(buf, sizeof(buf), "reg%d", dloc->op->reg1); pr_debug_dtp("found by insn track: %s%#x(%s) type-offset=%#x\n", offset_sign, offset, buf, dloc->type_offset); break; } if (ret == PERF_TMR_BAIL_OUT) break; /* Go up to the next scope and find blocks to the start */ prev_dst_ip = dst_ip; dst_ip = src_ip; } delete_basic_blocks(&basic_blocks); delete_var_types(var_types); return ret; } /* The result will be saved in @type_die */ static int find_data_type_die(struct data_loc_info *dloc, Dwarf_Die *type_die) { struct annotated_op_loc *loc = dloc->op; Dwarf_Die cu_die, var_die; Dwarf_Die *scopes = NULL; int reg, offset = loc->offset; int ret = -1; int i, nr_scopes; int fbreg = -1; int fb_offset = 0; bool is_fbreg = false; bool found = false; u64 pc; char buf[64]; enum type_match_result result = PERF_TMR_UNKNOWN; const char *offset_sign = ""; if (dloc->op->multi_regs) snprintf(buf, sizeof(buf), "reg%d, reg%d", dloc->op->reg1, dloc->op->reg2); else if (dloc->op->reg1 == DWARF_REG_PC) snprintf(buf, sizeof(buf), "PC"); else snprintf(buf, sizeof(buf), "reg%d", dloc->op->reg1); if (offset < 0) { offset = -offset; offset_sign = "-"; } pr_debug_dtp("-----------------------------------------------------------\n"); pr_debug_dtp("find data type for %s%#x(%s) at %s+%#"PRIx64"\n", offset_sign, offset, buf, dloc->ms->sym->name, dloc->ip - dloc->ms->sym->start); /* * IP is a relative instruction address from the start of the map, as * it can be randomized/relocated, it needs to translate to PC which is * a file address for DWARF processing. */ pc = map__rip_2objdump(dloc->ms->map, dloc->ip); /* Get a compile_unit for this address */ if (!find_cu_die(dloc->di, pc, &cu_die)) { pr_debug_dtp("cannot find CU for address %"PRIx64"\n", pc); ann_data_stat.no_cuinfo++; return -1; } reg = loc->reg1; offset = loc->offset; pr_debug_dtp("CU for %s (die:%#lx)\n", dwarf_diename(&cu_die), (long)dwarf_dieoffset(&cu_die)); if (reg == DWARF_REG_PC) { if (get_global_var_type(&cu_die, dloc, dloc->ip, dloc->var_addr, &offset, type_die)) { dloc->type_offset = offset; pr_debug_dtp("found by addr=%#"PRIx64" type_offset=%#x\n", dloc->var_addr, offset); pr_debug_type_name(type_die, TSR_KIND_TYPE); found = true; goto out; } } /* Get a list of nested scopes - i.e. (inlined) functions and blocks. */ nr_scopes = die_get_scopes(&cu_die, pc, &scopes); if (reg != DWARF_REG_PC && dwarf_hasattr(&scopes[0], DW_AT_frame_base)) { Dwarf_Attribute attr; Dwarf_Block block; /* Check if the 'reg' is assigned as frame base register */ if (dwarf_attr(&scopes[0], DW_AT_frame_base, &attr) != NULL && dwarf_formblock(&attr, &block) == 0 && block.length == 1) { switch (*block.data) { case DW_OP_reg0 ... DW_OP_reg31: fbreg = dloc->fbreg = *block.data - DW_OP_reg0; break; case DW_OP_call_frame_cfa: dloc->fb_cfa = true; if (die_get_cfa(dloc->di->dbg, pc, &fbreg, &fb_offset) < 0) fbreg = -1; break; default: break; } pr_debug_dtp("frame base: cfa=%d fbreg=%d\n", dloc->fb_cfa, fbreg); } } retry: is_fbreg = (reg == fbreg); if (is_fbreg) offset = loc->offset - fb_offset; /* Search from the inner-most scope to the outer */ for (i = nr_scopes - 1; i >= 0; i--) { Dwarf_Die mem_die; int type_offset = offset; if (reg == DWARF_REG_PC) { if (!die_find_variable_by_addr(&scopes[i], dloc->var_addr, &var_die, &type_offset)) continue; } else { /* Look up variables/parameters in this scope */ if (!die_find_variable_by_reg(&scopes[i], pc, reg, &type_offset, is_fbreg, &var_die)) continue; } pr_debug_dtp("found \"%s\" (die: %#lx) in scope=%d/%d (die: %#lx) ", dwarf_diename(&var_die), (long)dwarf_dieoffset(&var_die), i+1, nr_scopes, (long)dwarf_dieoffset(&scopes[i])); /* Found a variable, see if it's correct */ result = check_variable(dloc, &var_die, &mem_die, reg, type_offset, is_fbreg); if (result == PERF_TMR_OK) { if (reg == DWARF_REG_PC) { pr_debug_dtp("addr=%#"PRIx64" type_offset=%#x\n", dloc->var_addr, type_offset); } else if (reg == DWARF_REG_FB || is_fbreg) { pr_debug_dtp("stack_offset=%#x type_offset=%#x\n", fb_offset, type_offset); } else { pr_debug_dtp("type_offset=%#x\n", type_offset); } if (!found || is_better_type(type_die, &mem_die)) { *type_die = mem_die; dloc->type_offset = type_offset; found = true; } } else { pr_debug_dtp("failed: %s\n", match_result_str(result)); } pr_debug_location(&var_die, pc, reg); pr_debug_type_name(&mem_die, TSR_KIND_TYPE); } if (!found && loc->multi_regs && reg == loc->reg1 && loc->reg1 != loc->reg2) { reg = loc->reg2; goto retry; } if (!found && reg != DWARF_REG_PC) { result = find_data_type_block(dloc, &cu_die, scopes, nr_scopes, type_die); if (result == PERF_TMR_OK) { ann_data_stat.insn_track++; found = true; } } out: pr_debug_dtp("final result: "); if (found) { pr_debug_type_name(type_die, TSR_KIND_TYPE); ret = 0; } else { switch (result) { case PERF_TMR_NO_TYPE: case PERF_TMR_NO_POINTER: pr_debug_dtp("%s\n", match_result_str(result)); ann_data_stat.no_typeinfo++; break; case PERF_TMR_NO_SIZE: pr_debug_dtp("%s\n", match_result_str(result)); ann_data_stat.invalid_size++; break; case PERF_TMR_BAD_OFFSET: pr_debug_dtp("%s\n", match_result_str(result)); ann_data_stat.bad_offset++; break; case PERF_TMR_UNKNOWN: case PERF_TMR_BAIL_OUT: case PERF_TMR_OK: /* should not reach here */ default: pr_debug_dtp("no variable found\n"); ann_data_stat.no_var++; break; } ret = -1; } free(scopes); return ret; } /** * find_data_type - Return a data type at the location * @dloc: data location * * This functions searches the debug information of the binary to get the data * type it accesses. The exact location is expressed by (ip, reg, offset) * for pointer variables or (ip, addr) for global variables. Note that global * variables might update the @dloc->type_offset after finding the start of the * variable. If it cannot find a global variable by address, it tried to find * a declaration of the variable using var_name. In that case, @dloc->offset * won't be updated. * * It return %NULL if not found. */ struct annotated_data_type *find_data_type(struct data_loc_info *dloc) { struct dso *dso = map__dso(dloc->ms->map); Dwarf_Die type_die; /* * The type offset is the same as instruction offset by default. * But when finding a global variable, the offset won't be valid. */ dloc->type_offset = dloc->op->offset; dloc->fbreg = -1; if (find_data_type_die(dloc, &type_die) < 0) return NULL; return dso__findnew_data_type(dso, &type_die); } static int alloc_data_type_histograms(struct annotated_data_type *adt, int nr_entries) { int i; size_t sz = sizeof(struct type_hist); sz += sizeof(struct type_hist_entry) * adt->self.size; /* Allocate a table of pointers for each event */ adt->histograms = calloc(nr_entries, sizeof(*adt->histograms)); if (adt->histograms == NULL) return -ENOMEM; /* * Each histogram is allocated for the whole size of the type. * TODO: Probably we can move the histogram to members. */ for (i = 0; i < nr_entries; i++) { adt->histograms[i] = zalloc(sz); if (adt->histograms[i] == NULL) goto err; } adt->nr_histograms = nr_entries; return 0; err: while (--i >= 0) zfree(&(adt->histograms[i])); zfree(&adt->histograms); return -ENOMEM; } static void delete_data_type_histograms(struct annotated_data_type *adt) { for (int i = 0; i < adt->nr_histograms; i++) zfree(&(adt->histograms[i])); zfree(&adt->histograms); adt->nr_histograms = 0; } void annotated_data_type__tree_delete(struct rb_root *root) { struct annotated_data_type *pos; while (!RB_EMPTY_ROOT(root)) { struct rb_node *node = rb_first(root); rb_erase(node, root); pos = rb_entry(node, struct annotated_data_type, node); delete_members(&pos->self); delete_data_type_histograms(pos); zfree(&pos->self.type_name); free(pos); } } /** * annotated_data_type__update_samples - Update histogram * @adt: Data type to update * @evsel: Event to update * @offset: Offset in the type * @nr_samples: Number of samples at this offset * @period: Event count at this offset * * This function updates type histogram at @ofs for @evsel. Samples are * aggregated before calling this function so it can be called with more * than one samples at a certain offset. */ int annotated_data_type__update_samples(struct annotated_data_type *adt, struct evsel *evsel, int offset, int nr_samples, u64 period) { struct type_hist *h; if (adt == NULL) return 0; if (adt->histograms == NULL) { int nr = evsel->evlist->core.nr_entries; if (alloc_data_type_histograms(adt, nr) < 0) return -1; } if (offset < 0 || offset >= adt->self.size) return -1; h = adt->histograms[evsel->core.idx]; h->nr_samples += nr_samples; h->addr[offset].nr_samples += nr_samples; h->period += period; h->addr[offset].period += period; return 0; } static void print_annotated_data_header(struct hist_entry *he, struct evsel *evsel) { struct dso *dso = map__dso(he->ms.map); int nr_members = 1; int nr_samples = he->stat.nr_events; int width = 7; const char *val_hdr = "Percent"; if (evsel__is_group_event(evsel)) { struct hist_entry *pair; list_for_each_entry(pair, &he->pairs.head, pairs.node) nr_samples += pair->stat.nr_events; } printf("Annotate type: '%s' in %s (%d samples):\n", he->mem_type->self.type_name, dso__name(dso), nr_samples); if (evsel__is_group_event(evsel)) { struct evsel *pos; int i = 0; nr_members = 0; for_each_group_evsel(pos, evsel) { if (symbol_conf.skip_empty && evsel__hists(pos)->stats.nr_samples == 0) continue; printf(" event[%d] = %s\n", i++, pos->name); nr_members++; } } if (symbol_conf.show_total_period) { width = 11; val_hdr = "Period"; } else if (symbol_conf.show_nr_samples) { width = 7; val_hdr = "Samples"; } printf("============================================================================\n"); printf("%*s %10s %10s %s\n", (width + 1) * nr_members, val_hdr, "offset", "size", "field"); } static void print_annotated_data_value(struct type_hist *h, u64 period, int nr_samples) { double percent = h->period ? (100.0 * period / h->period) : 0; const char *color = get_percent_color(percent); if (symbol_conf.show_total_period) color_fprintf(stdout, color, " %11" PRIu64, period); else if (symbol_conf.show_nr_samples) color_fprintf(stdout, color, " %7d", nr_samples); else color_fprintf(stdout, color, " %7.2f", percent); } static void print_annotated_data_type(struct annotated_data_type *mem_type, struct annotated_member *member, struct evsel *evsel, int indent) { struct annotated_member *child; struct type_hist *h = mem_type->histograms[evsel->core.idx]; int i, nr_events = 0, samples = 0; u64 period = 0; int width = symbol_conf.show_total_period ? 11 : 7; struct evsel *pos; for_each_group_evsel(pos, evsel) { h = mem_type->histograms[pos->core.idx]; if (symbol_conf.skip_empty && evsel__hists(pos)->stats.nr_samples == 0) continue; samples = 0; period = 0; for (i = 0; i < member->size; i++) { samples += h->addr[member->offset + i].nr_samples; period += h->addr[member->offset + i].period; } print_annotated_data_value(h, period, samples); nr_events++; } printf(" %#10x %#10x %*s%s\t%s", member->offset, member->size, indent, "", member->type_name, member->var_name ?: ""); if (!list_empty(&member->children)) printf(" {\n"); list_for_each_entry(child, &member->children, node) print_annotated_data_type(mem_type, child, evsel, indent + 4); if (!list_empty(&member->children)) printf("%*s}", (width + 1) * nr_events + 24 + indent, ""); printf(";\n"); } int hist_entry__annotate_data_tty(struct hist_entry *he, struct evsel *evsel) { print_annotated_data_header(he, evsel); print_annotated_data_type(he->mem_type, &he->mem_type->self, evsel, 0); printf("\n"); /* move to the next entry */ return '>'; }