In case of register defined variable (found using find_data_type_global_reg), if the type of variable happens to be base type (example, long unsigned int), perf report captures it as:
12.85% long unsigned int long unsigned int +0 (no field) The above data type is actually referring to samples captured while accessing "r1" which represents current stack pointer in powerpc. register void *__stack_pointer asm("r1"); The dwarf debug contains this as: <<>> <1><18dd772>: Abbrev Number: 129 (DW_TAG_variable) <18dd774> DW_AT_name : (indirect string, offset: 0x11ba): current_stack_pointer <18dd778> DW_AT_decl_file : 51 <18dd779> DW_AT_decl_line : 1468 <18dd77b> DW_AT_decl_column : 24 <18dd77c> DW_AT_type : <0x18da5cd> <18dd780> DW_AT_external : 1 <18dd780> DW_AT_location : 1 byte block: 51 (DW_OP_reg1 (r1)) where 18da5cd is: <1><18da5cd>: Abbrev Number: 47 (DW_TAG_base_type) <18da5ce> DW_AT_byte_size : 8 <18da5cf> DW_AT_encoding : 7 (unsigned) <18da5d0> DW_AT_name : (indirect string, offset: 0x55c7): long unsigned int <<>> To make it more clear to the user, capture the DW_AT_name of the variable and save it as part of Dwarf_Global. Dwarf_Global is used so that it can be used and retrieved while presenting the result. Update "dso__findnew_data_type" function to set "var_name" if variable name is set as part of Dwarf_Global. Signed-off-by: Athira Rajeev <atraj...@linux.vnet.ibm.com> --- tools/perf/util/annotate-data.c | 30 ++++++++++++++++++++++++------ tools/perf/util/dwarf-aux.c | 1 + tools/perf/util/dwarf-aux.h | 1 + 3 files changed, 26 insertions(+), 6 deletions(-) diff --git a/tools/perf/util/annotate-data.c b/tools/perf/util/annotate-data.c index a5b4429ede57..8d05f3dbddf6 100644 --- a/tools/perf/util/annotate-data.c +++ b/tools/perf/util/annotate-data.c @@ -268,28 +268,37 @@ static void delete_members(struct annotated_member *member) } static struct annotated_data_type *dso__findnew_data_type(struct dso *dso, - Dwarf_Die *type_die) + Dwarf_Die *type_die, Dwarf_Global *global_die) { struct annotated_data_type *result = NULL; struct annotated_data_type key; struct rb_node *node; struct strbuf sb; + struct strbuf sb_var_name; char *type_name; + char *var_name = NULL; Dwarf_Word size; strbuf_init(&sb, 32); + strbuf_init(&sb_var_name, 32); if (die_get_typename_from_type(type_die, &sb) < 0) strbuf_add(&sb, "(unknown type)", 14); + if (global_die->name) { + strbuf_addstr(&sb_var_name, global_die->name); + var_name = strbuf_detach(&sb_var_name, NULL); + } type_name = strbuf_detach(&sb, NULL); dwarf_aggregate_size(type_die, &size); /* Check existing nodes in dso->data_types tree */ key.self.type_name = type_name; + key.self.var_name = var_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); + free(var_name); return result; } @@ -297,10 +306,12 @@ static struct annotated_data_type *dso__findnew_data_type(struct dso *dso, result = zalloc(sizeof(*result)); if (result == NULL) { free(type_name); + free(var_name); return NULL; } result->self.type_name = type_name; + result->self.var_name = var_name; result->self.size = size; INIT_LIST_HEAD(&result->self.children); @@ -1178,7 +1189,7 @@ static int find_data_type_block(struct data_loc_info *dloc, * cu_die and match with reg to identify data type die. */ static int find_data_type_global_reg(struct data_loc_info *dloc, int reg, Dwarf_Die *cu_die, - Dwarf_Die *type_die) + Dwarf_Die *type_die, Dwarf_Global *global_die) { Dwarf_Die vr_die; int ret = -1; @@ -1191,8 +1202,11 @@ static int find_data_type_global_reg(struct data_loc_info *dloc, int reg, Dwarf_ if (dwarf_offdie(dloc->di->dbg, var_types->die_off, &vr_die)) { if (die_get_real_type(&vr_die, type_die) == NULL) { dloc->type_offset = 0; + global_die->name = var_types->name; dwarf_offdie(dloc->di->dbg, var_types->die_off, type_die); } + global_die->die_offset = (long)dwarf_dieoffset(type_die); + global_die->cu_offset = (long)dwarf_dieoffset(cu_die); pr_debug_type_name(type_die, TSR_KIND_TYPE); ret = 0; pr_debug_dtp("found by CU for %s (die:%#lx)\n", @@ -1207,7 +1221,8 @@ static int find_data_type_global_reg(struct data_loc_info *dloc, int reg, Dwarf_ } /* The result will be saved in @type_die */ -static int find_data_type_die(struct data_loc_info *dloc, Dwarf_Die *type_die) +static int find_data_type_die(struct data_loc_info *dloc, Dwarf_Die *type_die, + Dwarf_Global *global_die) { struct annotated_op_loc *loc = dloc->op; Dwarf_Die cu_die, var_die; @@ -1221,6 +1236,8 @@ static int find_data_type_die(struct data_loc_info *dloc, Dwarf_Die *type_die) u64 pc; char buf[64]; + memset(global_die, 0, sizeof(Dwarf_Global)); + 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) @@ -1254,7 +1271,7 @@ static int find_data_type_die(struct data_loc_info *dloc, Dwarf_Die *type_die) dwarf_diename(&cu_die), (long)dwarf_dieoffset(&cu_die)); if (loc->reg_type == DWARF_REG_GLOBAL) { - ret = find_data_type_global_reg(dloc, reg, &cu_die, type_die); + ret = find_data_type_global_reg(dloc, reg, &cu_die, type_die, global_die); if (!ret) goto out; } @@ -1390,6 +1407,7 @@ struct annotated_data_type *find_data_type(struct data_loc_info *dloc) struct annotated_data_type *result = NULL; struct dso *dso = map__dso(dloc->ms->map); Dwarf_Die type_die; + Dwarf_Global global_die; dloc->di = debuginfo__new(dso__long_name(dso)); if (dloc->di == NULL) { @@ -1405,10 +1423,10 @@ struct annotated_data_type *find_data_type(struct data_loc_info *dloc) dloc->fbreg = -1; - if (find_data_type_die(dloc, &type_die) < 0) + if (find_data_type_die(dloc, &type_die, &global_die) < 0) goto out; - result = dso__findnew_data_type(dso, &type_die); + result = dso__findnew_data_type(dso, &type_die, &global_die); out: debuginfo__delete(dloc->di); diff --git a/tools/perf/util/dwarf-aux.c b/tools/perf/util/dwarf-aux.c index 44ef968a7ad3..9e61ff326651 100644 --- a/tools/perf/util/dwarf-aux.c +++ b/tools/perf/util/dwarf-aux.c @@ -1610,6 +1610,7 @@ static int __die_collect_vars_cb(Dwarf_Die *die_mem, void *arg) vt->reg = reg_from_dwarf_op(ops); vt->offset = offset_from_dwarf_op(ops); vt->next = *var_types; + vt->name = dwarf_diename(die_mem); *var_types = vt; return DIE_FIND_CB_SIBLING; diff --git a/tools/perf/util/dwarf-aux.h b/tools/perf/util/dwarf-aux.h index 24446412b869..406a5b1e269b 100644 --- a/tools/perf/util/dwarf-aux.h +++ b/tools/perf/util/dwarf-aux.h @@ -146,6 +146,7 @@ struct die_var_type { u64 addr; int reg; int offset; + const char *name; }; /* Return type info of a member at offset */ -- 2.43.0