diff options
Diffstat (limited to 'tools/perf/util/dwarf-aux.c')
| -rw-r--r-- | tools/perf/util/dwarf-aux.c | 69 |
1 files changed, 58 insertions, 11 deletions
diff --git a/tools/perf/util/dwarf-aux.c b/tools/perf/util/dwarf-aux.c index 559c953ca172..9267af204c7d 100644 --- a/tools/perf/util/dwarf-aux.c +++ b/tools/perf/util/dwarf-aux.c @@ -1388,18 +1388,19 @@ struct find_var_data { #define DWARF_OP_DIRECT_REGS 32 static bool match_var_offset(Dwarf_Die *die_mem, struct find_var_data *data, - u64 addr_offset, u64 addr_type, bool is_pointer) + s64 addr_offset, s64 addr_type, bool is_pointer) { Dwarf_Die type_die; Dwarf_Word size; + s64 offset = addr_offset - addr_type; - if (addr_offset == addr_type) { + if (offset == 0) { /* Update offset relative to the start of the variable */ data->offset = 0; return true; } - if (addr_offset < addr_type) + if (offset < 0) return false; if (die_get_real_type(die_mem, &type_die) == NULL) @@ -1414,14 +1415,42 @@ static bool match_var_offset(Dwarf_Die *die_mem, struct find_var_data *data, if (dwarf_aggregate_size(&type_die, &size) < 0) return false; - if (addr_offset >= addr_type + size) + if ((u64)offset >= size) return false; /* Update offset relative to the start of the variable */ - data->offset = addr_offset - addr_type; + data->offset = offset; return true; } +/** + * is_breg_access_indirect - Check if breg based access implies type + * dereference + * @ops: DWARF operations array + * @nops: Number of operations in @ops + * + * Returns true if the DWARF expression evaluates to the variable's + * value, so the memory access on that register needs type dereference. + * Returns false if the expression evaluates to the variable's address. + * This is called after check_allowed_ops. + */ +static bool is_breg_access_indirect(Dwarf_Op *ops, size_t nops) +{ + /* only the base register */ + if (nops == 1) + return false; + + if (nops == 2 && ops[1].atom == DW_OP_stack_value) + return true; + + if (nops == 3 && (ops[1].atom == DW_OP_deref || + ops[1].atom == DW_OP_deref_size) && + ops[2].atom == DW_OP_stack_value) + return false; + /* unreachable, OP not supported */ + return false; +} + /* Only checks direct child DIEs in the given scope. */ static int __die_find_var_reg_cb(Dwarf_Die *die_mem, void *arg) { @@ -1450,7 +1479,7 @@ static int __die_find_var_reg_cb(Dwarf_Die *die_mem, void *arg) if (data->is_fbreg && ops->atom == DW_OP_fbreg && check_allowed_ops(ops, nops) && match_var_offset(die_mem, data, data->offset, ops->number, - /*is_pointer=*/false)) + is_breg_access_indirect(ops, nops))) return DIE_FIND_CB_END; /* Only match with a simple case */ @@ -1462,11 +1491,11 @@ static int __die_find_var_reg_cb(Dwarf_Die *die_mem, void *arg) /*is_pointer=*/true)) return DIE_FIND_CB_END; - /* Local variables accessed by a register + offset */ + /* variables accessed by a register + offset */ if (ops->atom == (DW_OP_breg0 + data->reg) && check_allowed_ops(ops, nops) && match_var_offset(die_mem, data, data->offset, ops->number, - /*is_pointer=*/false)) + is_breg_access_indirect(ops, nops))) return DIE_FIND_CB_END; } else { /* pointer variables saved in a register 32 or above */ @@ -1476,11 +1505,11 @@ static int __die_find_var_reg_cb(Dwarf_Die *die_mem, void *arg) /*is_pointer=*/true)) return DIE_FIND_CB_END; - /* Local variables accessed by a register + offset */ + /* variables accessed by a register + offset */ if (ops->atom == DW_OP_bregx && data->reg == ops->number && check_allowed_ops(ops, nops) && match_var_offset(die_mem, data, data->offset, ops->number2, - /*is_poitner=*/false)) + is_breg_access_indirect(ops, nops))) return DIE_FIND_CB_END; } } @@ -1598,13 +1627,22 @@ static int __die_collect_vars_cb(Dwarf_Die *die_mem, void *arg) if (!check_allowed_ops(ops, nops)) return DIE_FIND_CB_SIBLING; - if (die_get_real_type(die_mem, &type_die) == NULL) + if (__die_get_real_type(die_mem, &type_die) == NULL) return DIE_FIND_CB_SIBLING; vt = malloc(sizeof(*vt)); if (vt == NULL) return DIE_FIND_CB_END; + /* Usually a register holds the value of a variable */ + vt->is_reg_var_addr = false; + + if (((ops->atom >= DW_OP_breg0 && ops->atom <= DW_OP_breg31) || + ops->atom == DW_OP_bregx || ops->atom == DW_OP_fbreg) && + !is_breg_access_indirect(ops, nops)) + /* The register contains an address of the variable. */ + vt->is_reg_var_addr = true; + vt->die_off = dwarf_dieoffset(&type_die); vt->addr = start; vt->reg = reg_from_dwarf_op(ops); @@ -1920,6 +1958,7 @@ struct find_scope_data { static int __die_find_scope_cb(Dwarf_Die *die_mem, void *arg) { struct find_scope_data *data = arg; + int tag = dwarf_tag(die_mem); if (dwarf_haspc(die_mem, data->pc)) { Dwarf_Die *tmp; @@ -1933,6 +1972,14 @@ static int __die_find_scope_cb(Dwarf_Die *die_mem, void *arg) data->nr++; return DIE_FIND_CB_CHILD; } + + /* + * If the DIE doesn't have the PC, we still need to check its children + * and siblings if it's a container like a namespace. + */ + if (tag == DW_TAG_namespace) + return DIE_FIND_CB_CONTINUE; + return DIE_FIND_CB_SIBLING; } |