Re: [linux-image-5.10.0-1-amd64] Requirement of pahole binary with CONFIG_DEBUG_INFO_BTF=y

[Sedat Dilek <sedat.dilek@gmail.com>]

On Mon, Jan 11, 2021 at 11:29 AM Salvatore Bonaccorso <carnil@debian.org> wrote:
>
>
> On Mon, Jan 11, 2021 at 09:57:43AM +0100, Sedat Dilek wrote:
> > Hi,
> >
> > yesterday, I installed linux-image-5.10.0-1-amd64 version 5.10.5-1
> > from Debian/unstable.
> >
> > I am building custom Linux-kernels mostly to test with LLVM/Clang and
> > use Debian's kernel-config file as a base for my work.
> >
> > With CONFIG_DEBUG_INFO_BTF=y there is a requirement for pahole binary
> > from dwarves package.
> >
> > The requirement is coded in [1]:
> >
> > if ! [ -x "$(command -v ${PAHOLE})" ]; then
> > echo >&2 "BTF: ${1}: pahole (${PAHOLE}) is not available"
> > return 1
> > fi
> >
> > Is there an install-recommendation for dwarves package?
> > If not - I would like to open a bug-report.
> >
> > If you need further information, please let me know.
>
> this change happened in
> https://salsa.debian.org/kernel-team/linux/-/commit/929891281c61ce4403ddd869664c949692644a2f
> (actually earlier, then reverted and enabled for a subset of
> architectures wiith the above commit).
>
> For the Debian build it adds as well the Build-Depends on dwarves (>=
> 1.16~).
>
> Did I understood your question correctly?
>

Hi Salvatore,

That commit looks good to me.

Anyway, it breaks here CONFIG_DEBUG_INFO_BTF=y:

+ [ -n y -a -n y ]
+ info BTFIDS vmlinux
+ [  != silent_ ]
+ printf   %-7s %s\n BTFIDS vmlinux
 BTFIDS  vmlinux
+ ./tools/bpf/resolve_btfids/resolve_btfids vmlinux
FAILED: load BTF from vmlinux: Invalid argument
+ on_exit
+ [ 255 -ne 0 ]
+ cleanup
+ rm -f .btf.vmlinux.bin.o

Any comments?

Thanks.

Regards,
- Sedat -