On Thu, Jan 14, 2021 at 9:11 PM Sedat Dilek <sedat.dilek@xxxxxxxxx> wrote:
>
> On Thu, Jan 14, 2021 at 8:13 PM Yonghong Song <yhs@xxxxxx> wrote:
> >
> >
> >
> > On 1/14/21 11:01 AM, Nick Desaulniers wrote:
> > > On Thu, Jan 14, 2021 at 10:53 AM Nick Desaulniers
> > > <ndesaulniers@xxxxxxxxxx> wrote:
> > >>
> > >> On Wed, Jan 13, 2021 at 10:18 PM Sedat Dilek <sedat.dilek@xxxxxxxxx> wrote:
> > >>>
> > >>> On Wed, Jan 13, 2021 at 11:25 PM Caroline Tice <cmtice@xxxxxxxxxx> wrote:
> > >>>>
> > >>>> On Tue, Jan 12, 2021 at 3:17 PM Sedat Dilek <sedat.dilek@xxxxxxxxx> wrote:
> > >>>>>
> > >>>>> Unfortunately, I see with CONFIG_DEBUG_INFO_DWARF5=y and
> > >>>>> CONFIG_DEBUG_INFO_BTF=y:
> > >>>>>
> > >>>>> die__process_inline_expansion: DW_TAG_INVALID (0x48) @ <0x3f0dd5a> not handled!
> > >>>>> die__process_function: DW_TAG_INVALID (0x48) @ <0x3f0dd69> not handled!
> > >>
> > >> I can confirm that I see a stream of these warnings when building with
> > >> this patch series applied, and those two configs enabled.
> > >>
> > >> rebuilding with `make ... V=1`, it looks like the call to:
> > >>
> > >> + pahole -J .tmp_vmlinux.btf
> > >>
> > >> is triggering these.
> > >>
> > >> Shall I send a v4 that adds a Kconfig dependency on !DEBUG_INFO_BTF?
> > >> Does pahole have a bug tracker?
> >
> > pahole could have issues for dwarf5 since as far as I know, people just
> > use dwarf2/dwarf4 with config functions in the kernel.
> >
> > Where is the link of the patch to add CONFIG_DEBUG_INFO_DWARF5 to linux?
> > I think you can add CONFIG_DEBUG_INFO_DWARF5 to kernel with dependency
> > of !CONFIG_DEBUG_INFO_BTF. At the same time, people can debug pahole
> > issues. Once it is resolved, !CONFIG_DEBUG_INFO_BTF dependency can be
> > removed with proper pahole version change in kernel.
> >
>
> Yeah, sounds like a good idea.
>
Today, I have observed and reported (see [1]) bpf/btf/pahole issues
with Clang v12 (from apt.llvm.org) and DWARF-4 ("four").
Cannot speak for other compilers and its version.
- Sedat -
[1] https://lore.kernel.org/bpf/CA+icZUWb3OyaSQAso8LhsRifZnpxAfDtuRwgB786qEJ3GQ+kRw@xxxxxxxxxxxxxx/T/#m6d05cc6c634e9cee89060b2522abc78c3705ea4c
>
> > >
> > > FWIW, my distro packages pahole v1.17; rebuilt with ToT v1.19 from
> > > source and also observe the issue.
> > >
