Re: [PATCH 0/2] fs: support $ORIGIN in ELF interpreter paths

[David Laight <david.laight.linux@gmail.com>]

On Fri, 26 Jun 2026 15:34:12 +0200
Jann Horn <jannh@google.com> wrote:

> On Fri, Jun 26, 2026 at 3:26 PM David Laight
> <david.laight.linux@gmail.com> wrote:
> > On Fri, 26 Jun 2026 14:39:22 +0200
> > Jann Horn <jannh@google.com> wrote:
> >  
> > > On Thu, Jun 25, 2026 at 10:50 AM Christian Brauner <brauner@kernel.org> wrote:  
> > > > The arguments I have heard from various people so far are:
> > > >
> > > > (1) Userspace would be able to clone a random chroot to /woot and run a
> > > >     binary from it without having to set up a complicated sandbox
> > > >     effectively making dynamically linked binaries more like static
> > > >     binaries in a sense.
> > > >
> > > > (2) Quote:
> > > >     "If you debootstrap/dnf a chroot to some location in your
> > > >     home dir and try to run a binary from it, that it tries to load the
> > > >     libraries from your /usr is a pretty unintuitive and not at all
> > > >     useful behavior."
> > > >
> > > > (3) Quote:
> > > >     "[Various remote execution things run in locked down containers that
> > > >     disable userns, which makes the sandbox impossible and hence our
> > > >     builds wouldn't work there."  
> > >
> > > FWIW I think someone also mentioned to me that it would make things
> > > easier for them if they could build a piece of software in one
> > > environment and then bundle it up with all required libraries and such
> > > and run it in a very different environment, without
> > > container/sandboxing stuff and without static linking. But I guess
> > > that's kinda niche.  
> >
> > The problem with 'ship the shared libraries with the application' is
> > that you get all the problems of static linking.
> > If there is a bug in the library code you can't fix it without getting the
> > 3rd party to rebuild their application package.  
> 
> Yes, it's appropriate for weird use cases like "I want to run this
> historical version of the software and its dependencies", it's not
> necessarily a good idea for normal application use.

That's what LD_LIBRARY_PATH is for ...

And if you want to use a different elf interpreter just run it and pass the
program name and arguments to it. eg:
	/lib64/ld-linux-x64-64.so.2 /bin/echo fubar
Last time I did that I was trying to run non-linux ppc elf program.
I got part way there, but needed to build a lot more of libc.

	David