Re: Segfault in pahole 1.18 when building kernel 5.9.1 for arm64

[Arnaldo Carvalho de Melo]

Em Tue, Oct 20, 2020 at 10:10:19AM -0700, Andrii Nakryiko escreveu:
> On Tue, Oct 20, 2020 at 10:05 AM Hao Luo <haoluo@xxxxxxxxxx> wrote:
> > Thanks for reporting this and cc'ing me. I forgot to update the error
> > messages when renaming the flags. I will send a patch to fix the error
> > message.

> > The commit

> > commit f3d9054ba8ff1df0fc44e507e3a01c0964cabd42
> > Author:     Hao Luo <haoluo@xxxxxxxxxx>
> > AuthorDate: Wed Jul 8 13:44:10 2020 -0700

> >      btf_encoder: Teach pahole to store percpu variables in vmlinux BTF.

> > encodes kernel global variables into BTF so that bpf programs can
> > directly access them. If there is no need to access kernel global
> > variables, it's perfectly fine to use '--btf_encode_force' to skip
> > encoding bad symbols into BTF, or '--skip_encoding_btf_vars' to skip
> > encoding all global vars all together. I will add these info into the
> > updated error message.

> > Also cc bpf folks for attention of this bug.

> I've already fixed the message as part of
> 2e719cca6672 ("btf_encoder: revamp how per-CPU variables are encoded")

> It's currently still in the tmp.libbtf_encoder branch in pahole repo.

I'm now running:

  $ grep BTF=y ../build/s390x-v5.9.0+/.config
  CONFIG_DEBUG_INFO_BTF=y
  $ make -j24 CROSS_COMPILE=s390x-linux-gnu- ARCH=s390 O=../build/s390x-v5.9.0+/

To do the last test I wanted before moving it to master.

- Arnaldo