diff --git a/tools/perf/util/probe-finder.c b/tools/perf/util/probe-finder.c index b4c93659929a..03b469197a03 100644 --- a/tools/perf/util/probe-finder.c +++ b/tools/perf/util/probe-finder.c @@ -249,6 +249,33 @@ static int die_get_byte_size(Dwarf_Die *tp_die) return (int)ret; } +/* Get data_member_location offset */ +static int die_get_data_member_location(Dwarf_Die *mb_die, Dwarf_Word *offs) +{ + Dwarf_Attribute attr; + Dwarf_Op *expr; + size_t nexpr; + int ret; + + if (dwarf_attr(mb_die, DW_AT_data_member_location, &attr) == NULL) + return -ENOENT; + + if (dwarf_formudata(&attr, offs) != 0) { + /* DW_AT_data_member_location should be DW_OP_plus_uconst */ + ret = dwarf_getlocation(&attr, &expr, &nexpr); + if (ret < 0 || nexpr == 0) + return -ENOENT; + + if (expr[0].atom != DW_OP_plus_uconst || nexpr != 1) { + pr_debug("Unable to get offset:Unexpected OP %x (%zd)\n", + expr[0].atom, nexpr); + return -ENOTSUP; + } + *offs = (Dwarf_Word)expr[0].number; + } + return 0; +} + /* Return values for die_find callbacks */ enum { DIE_FIND_CB_FOUND = 0, /* End of Search */ @@ -482,9 +509,9 @@ static int convert_variable_fields(Dwarf_Die *vr_die, const char *varname, Dwarf_Die *die_mem) { struct kprobe_trace_arg_ref *ref = *ref_ptr; - Dwarf_Attribute attr; Dwarf_Die type; Dwarf_Word offs; + int ret; pr_debug("converting %s in %s\n", field->name, varname); if (die_get_real_type(vr_die, &type) == NULL) { @@ -542,17 +569,17 @@ static int convert_variable_fields(Dwarf_Die *vr_die, const char *varname, } /* Get the offset of the field */ - if (dwarf_attr(die_mem, DW_AT_data_member_location, &attr) == NULL || - dwarf_formudata(&attr, &offs) != 0) { + ret = die_get_data_member_location(die_mem, &offs); + if (ret < 0) { pr_warning("Failed to get the offset of %s.\n", field->name); - return -ENOENT; + return ret; } ref->offset += (long)offs; /* Converting next field */ if (field->next) return convert_variable_fields(die_mem, field->name, - field->next, &ref, die_mem); + field->next, &ref, die_mem); else return 0; }