[systemd-devel] Does coredumpctl info support minidebuginfo / gnu_debugdata ?

[Etienne Cordonnier]

Hi,
for future reference the issue in Fedora was the configuration
"ProtectHome=yes" in systemd-coredump's service file (Ubuntu does the
same), which makes the home directory invisible to systemd-coredump, and
thus "coredumpctl info" shows "n/a" instead of function names in call
stacks even if the binaries have full debug symbols.

Etienne

On Tue, Nov 28, 2023 at 1:11 PM Etienne Cordonnier <ecordonnier at snap.com>
wrote:

> I found the issue in the yocto based distribution: elfutils / libdw was
> compiled without xz support, and was thus unable to extract the
> minidebuginfo symbol names.
> On Ubuntu / Fedora, I don't know exactly what the issue is.
>
> Etienne
>
> On Tue, Nov 21, 2023 at 11:53 PM Etienne Cordonnier <ecordonnier at snap.com>
> wrote:
>
>> Thanks for your reply. I have tested with Fedora 39 and indeed
>> coredumpctl info shows function names when a binary provided by a Fedora
>> package crashes. However, when I compile a test binary on Fedora, even with
>> debug symbols enabled (I tried -g and -ggdb), and I then send kill -SEGV my
>> binary, coredumpctl info shows "n/a" instead of the function names of my
>> test binary. I also tried to inject minidebuginfo into my binary file with
>> the same result.
>>
>> Do you know what I should do so that coredumpctl info also works with
>> binary files I compile? (I added full reproduction steps including the code
>> of this test binary to
>> https://unix.stackexchange.com/questions/761966/how-to-get-symbolized-call-stacks-with-coredumpctl-info
>> ).
>>
>> Etienne
>>
>> On Fri, Nov 17, 2023 at 10:03 AM Lennart Poettering <
>> lennart at poettering.net> wrote:
>>
>>> On Do, 16.11.23 18:37, Etienne Cordonnier (ecordonnier at snap.com) wrote:
>>>
>>> > Hello,
>>> > I am testing a yocto based system, where it seems that "coredumpctl
>>> info"
>>> > isn't able to use minidebuginfo / gnu_debugdata to extract a symbolized
>>> > call-stack. I saw in the code that coredumpctl uses elfutils / libdwfl
>>> in
>>> > order to extract a call-stack, and as far as I understand libdwfl
>>> supports
>>> > minidebuginfo since this commit (
>>> >
>>> https://urldefense.proofpoint.com/v2/url?u=https-3A__sourceware.org_git_-3Fp-3Delfutils.git-3Ba-3Dcommit-3Bh-3D5083a70d3b64946fa47ea5766943a15a3ecc6891&d=DwIBAg&c=ncDTmphkJTvjIDPh0hpF_4vCHvabgGkICC2epckfdiw&r=AhkbNonVuMIGRfPx_Qj9TsRih1DULJTKUkSGa66m67E&m=HRBTXvbd-s9li256Vbbs9zIn33TULJrpWyLD4WV4rEtaedXG1zYgtpXt1vN3eolJ&s=WjU-C5bJAjCxwlzGD-CwjTBUFN_ZEr7Z1pFNC54_HU0&e=
>>> > ).
>>> >
>>> > Is there a configuration / build-option / etc. to enable support for
>>> > minidebuginfo in coredumpctl? If no is it on the roadmap? The
>>> advantage of
>>> > minidebuginfo is that it is much smaller than full debug symbols.
>>>
>>> Fedora has been using minidebuginfo since ~10y or so, and
>>> coredumctl/libdwfl has been working fine with it. So it certainly
>>> works, it's how this all works on my local machine since forever.
>>>
>>> Maybe ask your distro for help, it's generally an integration issue of
>>> distributions i this doesn't work.
>>>
>>> Lennart
>>>
>>> --
>>> Lennart Poettering, Berlin
>>>
>>
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