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Date: Sat, 18 Aug 2012 12:07:34 -0400 (EDT)
From: idunham@...abit.com
To: musl@...ts.openwall.com
Subject: Re: Building without -Wl,-Bsymbolic-functions

> On Sat, Aug 18, 2012 at 01:38:23PM +0200, Jens wrote:
>>
>> Hi!
>>
>> Im building musl inside an oldish uclibc environment based on uclibc
>> 0.9.30.1, gcc 4.1.2 and GNU ld version 2.17.
>>
>> The linker does not accept -Bsymbolic-functions.
>>
>> Im now building the shared library despite of this.
>>
>> How broken will the musl libc be without -Bsymbolic-functions ?
>
> If building without it entirely, the shared libc will just crash.
>
> If replacing it with -Bsymbolic, it will run, but global variables in
> libc that are accessed by the application (e.g. environ, optind, ...)
> will actually have separate copies in libc and the application, and
> thus the app won't work as expected.
Last I checked, ISTR it was "Illegal instruction" or segfault (even for
hello world); I forget which was which, but both did not work at all.

> A patch to add -Bsymbolic-functions to old binutils would be very
> welcome... In the mean time, you could compile a new ld and pass the
> -B option to gcc to give it the path for the new ld.
The patch isn't trivial to get right, but 2.17.50 (20070703) is a
significant improvement in many other ways (a few code generation fixes
among them)...
I've built a tarball, but not really posted it publicly (tarballs in git
is really nasty 8-)* ).

Interestingly, -B is not needed if you just put the desired version first
in your path. (I found that out trying 2.17/2.17.50 on an Ubuntu host
Isaac Dunham

*see github.com/idunham/srcs if you still dare.


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