Re: Bug#1076564: pahole BTF processing seems flaky on powerpc

Domenico Andreoli <[email protected]> Fri, 19 Jul 2024 23:20:54 +0200

Newsgroups	gmane.comp.debugging.dwarves,gmane.linux.debian.devel.kernel,gmane.linux.debian.ports.powerpc
Message-ID	<ZprYtq5UQ1KDMw_v@localhost>

CCing debian-kernel and debian-powerpc

On Fri, Jul 19, 2024 at 04:13:00PM -0300, Arnaldo Carvalho de Melo wrote:
> Adding Alan and Jiri to the CC list.
> 
> On Fri, Jul 19, 2024 at 08:53:24AM +0200, Domenico Andreoli wrote:
> > Hi Arnaldo,
> > 
> > On Thu, Jul 18, 2024 at 11:56:09PM +0200, Ben Hutchings wrote:
> > > Package: pahole
> > > Version: 1.27-1
> > > Severity: normal
> > > X-Debbugs-Cc: [email protected]
> > > 
> > > Several kernel builds on powerpc have failed recently:
> > > 
> > > 6.8.12-1:    https://buildd.debian.org/status/fetch.php?pkg=linux&arch=powerpc&ver=6.8.12-1&stamp=1717234422&raw=1
> > > 6.9.9-1:     https://buildd.debian.org/status/fetch.php?pkg=linux&arch=powerpc&ver=6.9.9-1&stamp=1720906547&raw=1
> > > 6.10-1~exp1: https://buildd.debian.org/status/fetch.php?pkg=linux&arch=powerpc&ver=6.10-1%7Eexp1&stamp=1721287862&raw=1
> > > 
> > > Note, these log files are up to 270 MB in size and should be
> > > downloaded; at least Firefox becomes unresponsive when trying to
> > > display them.
> > > 
> > > For each of these, the failure seems to start with an error from
> > > pahole such as:
> > > 
> > >     [102044] ARRAY (anon) type_id=99491 index_type_id=14 nr_elems=12 Error emitting BTF type
> > >     Encountered error while encoding BTF.
> > 
> > Does the above error ring any bell?
> 
> Nope
>  
> > Is there anything I can do to help?
> 
> From the 6.10-1~exp1:
> https://buildd.debian.org/status/fetch.php?pkg=linux&arch=powerpc&ver=6.10-1%7Eexp1&stamp=1721287862&raw=1
> file:
> 
> + LLVM_OBJCOPY=powerpc-linux-gnu-objcopy pahole -J -j --btf_features=encode_force,var,float,enum64,decl_tag,type_tag,optimized_func,consistent_func --lang_exclude=rust .tmp_vmlinux.btf
> 
> Can I have access to that .tmp_vmlinux.btf file so that I can try to
> reproduce it here?

I don't have access to the build host (blaauw2) and I've some doubts
it would still have that file.

Maybe our kernel team and powerpc porters have suggestions?

Dom

-- 
rsa4096: 3B10 0CA1 8674 ACBA B4FE  FCD2 CE5B CF17 9960 DE13
ed25519: FFB4 0CC3 7F2E 091D F7DA  356E CC79 2832 ED38 CB05

signature.asc (application/pgp-signature, 833 B)