Re: [musl] Better backtrace from core dump

[Michal Nowak <mnowak@isc.org>]

Thanks Timo, this worked for me.

Michal

On 23/06/2020 14:12, Timo Teräs wrote:
> Hi
> 
> Install musl-dbg package to get the debug symbols.
> 
> Timo
> 
> On Tue, 23 Jun 2020, 14.43 Michal Nowak, <mnowak@isc.org 
> <mailto:mnowak@isc.org>> wrote:
> 
>     Hi,
> 
>     in GitLab we have jobs which run BIND system tests on different
>     operating system, mostly in Docker on Debian 10 but too in KVM virtual
>     machines for non-Linux operating systems. If the test produces core
>     dump, we generate backtrace out of it while still in the CI.
> 
>     For all C libraries but for musl we get reasonable backtraces, e.g.
>     https://gitlab.isc.org/isc-projects/bind9/-/jobs/970585, but for Alpine
>     Linux 3.11 (musl 1.1.24-r2 & GCC 9.2.0-r4) we get something like this
>     (https://gitlab.isc.org/isc-projects/bind9/-/jobs/970568):
> 
>     warning: Can't read pathname for load map: No error information.
>     Core was generated by
>     `/builds/isc-projects/bind9/bin/named/.libs/lt-named -D statistics-ns3
>     -X named.'.
>     Program terminated with signal SIGABRT, Aborted.
>     #0  0x00007fb708ec39ee in setjmp () from /lib/ld-musl-x86_64.so.1
>     [Current thread is 1 (LWP 1274)]
>     #0  0x00007fb708ec39ee in setjmp () from /lib/ld-musl-x86_64.so.1
>     #1  0x00007fb708ec3b49 in raise () from /lib/ld-musl-x86_64.so.1
>     #2  0x804ad6685d596f46 in ?? ()
>     #3  0x00007fb708bd1030 in ns_modules () from
>     /builds/isc-projects/bind9/lib/ns/.libs/libns.so.1702
>     #4  0x00007fb708e59edf in ?? () from
>     /builds/isc-projects/bind9/lib/isc/.libs/libisc.so.1702
>     #5  0x0000000042756621 in ?? ()
>     #6  0x00007fb7069c9db0 in ?? ()
>     #7  0x0000001800000018 in ?? ()
>     #8  0x00007fb708f0e873 in ?? () from /lib/ld-musl-x86_64.so.1
>     #9  0x0000000000000008 in ?? ()
>     #10 0x00007fb7069ca0e8 in ?? ()
>     #11 0x00007fb7069ca0d0 in ?? ()
>     #12 0x00007fb708e32d12 in isc_hash_function (data=0x459, length=0,
>     case_sensitive=<optimized out>) at hash.c:117
> 
>     This is how we generate the backtrace:
> 
>         "${top_builddir}/libtool" --mode=execute gdb --batch
>     --command=run.gdb --core="$coredump" -- "$binary"
> 
>     The GDB command can be either 'bt' or 'thread apply all bt full' (for
>     more on the GDB invocation, see
>     https://gitlab.isc.org/isc-projects/bind9/-/blob/main/bin/tests/system/run.sh.in#L268).
> 
>     CFLAGS used:
> 
>         -fno-omit-frame-pointer -fno-optimize-sibling-calls -O1 -g -Wall
>     -Wextra
> 
>     This is what we install on top of the stock Alpine Linux 3.11 Docker
>     image:
>     https://gitlab.isc.org/isc-projects/images/-/blob/main/docker/bind9/alpine-template/Dockerfile.
> 
>     Are there other packages, we should get into the image to get better
>     backtraces?
> 
>     Should we use something else than GDB?
> 
>     Should we add some compiler flags?
> 
>     Thanks,
>     Michal
>