Em Wed, Nov 11, 2020 at 12:26:29PM +0100, Daniel Borkmann escreveu: > On 11/10/20 4:40 PM, Jiri Olsa wrote: > > With upcoming changes to pahole, that change the way how and > > which kernel functions are stored in BTF data, we need a way > > to recognize iterator functions. > > > > Iterator functions need to be in BTF data, but have no real > > body and are currently placed in .init.text section, so they > > are freed after kernel init and are filtered out of BTF data > > because of that. > > > > The solution is to place these functions under new section: > > .init.bpf.preserve_type > > > > And add 2 new symbols to mark that area: > > __init_bpf_preserve_type_begin > > __init_bpf_preserve_type_end > > > > The code in pahole responsible for picking up the functions will > > be able to recognize functions from this section and add them to > > the BTF data and filter out all other .init.text functions. > > > > Cc: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx> > > Suggested-by: Yonghong Song <yhs@xxxxxx> > > Signed-off-by: Jiri Olsa <jolsa@xxxxxxxxxx> > > LGTM, applied, thanks! Also added a reference to the pahole commit Applied to what branch? I'm trying to test it now :-) - Arnaldo > to the commit log so that this info doesn't get lost in the void > plus carried over prior Acks given nothing changed logically in the > patch. > > P.s.: I've been wondering whether we also need to align the begin/end > symbols via ALIGN_FUNCTION() in case ld might realign to a different > boundary on later passes but this seems neither the case for .init.text > right now, likely since it doesn't matter for kallsyms data in our > particular case. -- - Arnaldo
