Re: [PATCH] ld.so: add an --argv0 option

[Vincent Mihalkovic <vmihalko@redhat.com>]

Hi,

Sorry, I forgot to CC the libc-alpha mailing-list on my reply.

We do not need the option for shell scripting, where it is indeed not
needed,
as you say.  We are developing a tool for running dynamic analysis tools on
RPM packages fully automatically.  The tool appends custom linker flags
while
executing the %build section of RPMs to make the binaries use our custom ELF
interpreter.  While running the %check section, the interpreter takes care
of
running the binaries built in %build through the selected dynamic analyzer
in
a way that does not break the testing framework.  For this to work, we need
to run dynamic linker explicitly.  There is currently no way to preserve the
original argv[0], which some programs are sensitive to.  This unnecessarily
breaks the tests running in %check of some RPM packages.

An experimental implementation of the custom ELF interpreter is available
here:

    https://github.com/kdudka/cswrap/pull/2

thanks for considering this idea,
vincent mihalkovic

On Wed, Jul 22, 2020 at 11:00 AM Florian Weimer <fweimer@redhat.com> wrote:

> * Vincent Mihalkovic via Libc-alpha:
>
> > a few years ago there was an effort for adding --argv0 option:
> > https://sourceware.org/legacy-ml/libc-alpha/2016-04/msg00576.html.
> > I made the old patch actual for version 2.31.9000, added a test case and
> > changelog.
>
> Many shells support “exec -a” to get a similar effect.  The advantage is
> that this does not perturb the argument vector layout.  Given that, I
> think promoting --argv0 would merely introduce further compatibility
> issues.
>
> Thanks,
> Florian
>
>