On Fri, Nov 6, 2020 at 2:25 PM Jiri Olsa <jolsa@xxxxxxxxxx> wrote: > > hi, > because of gcc bug [1] we can no longer rely on DW_AT_declaration > attribute to filter out declarations and end up with just > one copy of the function in the BTF data. > > It seems this bug is not easy to fix, but regardless if the > it's coming soon, it's probably good idea not to depend so > much only on dwarf data and make some extra checks. > > Thus for function encoding we are now doing following checks: > - argument names are defined for the function > - there's symbol and address defined for the function > - function address belongs to ftrace locations (new in v2) > - function is generated only once > > v4 changes: > - added acks > - renames and change functions_valid to be local var [Andrii] > - fixed error path (return err) of collect_symbols > > v3 changes: > - added Hao's ack for patch 1 > - fixed realloc memory leak [Andrii] > - fixed addrs_cmp function [Andrii] > - removed SET_SYMBOL macro [Andrii] > - fixed the 'valid' function logic > - added .init.bpf.preserve_type check > - added iterator functions to new kernel section > .init.bpf.preserve_type [Yonghong] > > v2 changes: > - add check ensuring functions belong to ftrace's mcount > locations, this way we ensure to have in BTF only > functions available for ftrace - patch 2 changelog > describes all details > - use collect* function names [Andrii] > - use conventional size increase in realloc [Andrii] > - drop elf_sym__is_function check > - drop patch 3, it's not needed, because we follow ftrace > locations > > thanks, > jirka > > > [1] https://gcc.gnu.org/bugzilla/show_bug.cgi?id=97060 > For the series: Acked-by: Andrii Nakryiko <andrii@xxxxxxxxxx>
