[PATCH v3] binfmt_elf: Dump smaller VMAs first in ELF cores

[Michael Stapelberg <michael@stapelberg.ch>]

Hey Brian and folks

> […]
> backtrace, and it turned out to be a non-trivial problem. Instead, we
> try simply sorting the VMAs by size, which has the intended effect.
> […]
> Still need to run rr tests on this, per Kees Cook's suggestion, will
> update back once done. GDB and readelf show that this patch works
> without issue though.

I think in your testing, you probably did not try the eu-stack tool
from the elfutils package, because I think I found a bug:

Current elfutils cannot symbolize core dumps created by Linux 6.12+.
I noticed this because systemd-coredump(8) uses elfutils, and when
a program crashed on my machine, syslog did not show function names.

I reported this issue with elfutils at:
https://sourceware.org/bugzilla/show_bug.cgi?id=32713
…but figured it would be good to give a heads-up here, too.

Is this breakage sufficient reason to revert the commit?
Or are we saying userspace just needs to be updated to cope?

Thanks
Best regards
Michael