On Tue, 2023-03-28 at 12:26 -0300, Arnaldo Carvalho de Melo wrote: [...] > Sure, but look: > > > > - struct qdisc_size_table * stab; /* 32 8 */ > > > + struct qdisc_size_table stab; /* 32 8 */ > > Its the DW_TAG_pointer_type that is getting lost somehow: > > <1><b0af32>: Abbrev Number: 81 (DW_TAG_structure_type) > <b0af33> DW_AT_name : (indirect string, offset: 0xe825): Qdisc > <b0af37> DW_AT_byte_size : 384 > <b0af39> DW_AT_decl_file : 223 > <b0af3a> DW_AT_decl_line : 72 > > <SNIP> > > <2><b0af77>: Abbrev Number: 65 (DW_TAG_member) > <b0af78> DW_AT_name : (indirect string, offset: 0x4745ff): stab > <b0af7c> DW_AT_type : <0xb0b76b> > <b0af80> DW_AT_decl_file : 223 > <b0af81> DW_AT_decl_line : 99 > <b0af82> DW_AT_data_member_location: 32 > > <SNIP> > > <1><b0b76b>: Abbrev Number: 61 (DW_TAG_pointer_type) > <b0b76c> DW_AT_type : <0xb0b77a> > <2><b0b770>: Abbrev Number: 62 (User TAG value: 0x6000) > <b0b771> DW_AT_name : (indirect string, offset: 0x378): btf_type_tag > <b0b775> DW_AT_const_value : (indirect string, offset: 0x6e93): rcu > <2><b0b779>: Abbrev Number: 0 > <1><b0b77a>: Abbrev Number: 69 (DW_TAG_structure_type) > <b0b77b> DW_AT_name : (indirect string, offset: 0x6e5ed): qdisc_size_table > <b0b77f> DW_AT_byte_size : 64 > <b0b780> DW_AT_decl_file : 223 > <b0b781> DW_AT_decl_line : 56 > > > So it's all there in the DWARF info: > > b0af77 has type 0xb0b76b which is a DW_TAG_pointer_type that has type > 0xb0b77a, that is DW_TAG_structure_type. > > Now lets see how this was encoded into BTF: > > [4725] STRUCT 'Qdisc' size=384 vlen=28 > <SNIP> > 'stab' type_id=4790 bits_offset=256 > <SNIP> > [4790] PTR '(anon)' type_id=4789 > <SNIP> > [4789] TYPE_TAG 'rcu' type_id=4791 > <SNIP> > [4791] STRUCT 'qdisc_size_table' size=64 vlen=5 > 'rcu' type_id=320 bits_offset=0 > 'list' type_id=87 bits_offset=128 > 'szopts' type_id=4792 bits_offset=256 > 'refcnt' type_id=16 bits_offset=448 > 'data' type_id=4659 bits_offset=480 > > So it all seems ok, we should keep all the info and teach fprintf to > handle TYPE_TAG. > > Which you tried, but somehow the '*' link is missing. Yep, thanks a lot for the analysis, I will take a look. Hopefully will send v2 tomorrow. > > - Arnaldo
