Re: Versioning mess proved!!!

[Franz Sirl <Franz dot Sirl-kernel at lauterbach dot com>]

On Sun, 01 Oct 2000, Geoff Keating wrote:
> > From: Franz Sirl <Franz.Sirl-kernel@lauterbach.com>
> > Date: Sun, 1 Oct 2000 23:08:28 +0200
> > Cc: Ulrich Drepper <drepper@redhat.com>, Jack Howarth <howarth@fuse.net>,
> >         libc-alpha@sourceware.cygnus.com, aj@suse.de
> >
> > On Sun, 01 Oct 2000, Philip Blundell wrote:
> > > >Uli, actually I think your patch broke this, WEAK_GMON_START was never
> > > >defined for PPC, we always had the dummy weak __gmon_start__() routine
> > > > which Philips patch removed. Can we really change this without
> > > > breaking binary compatibility?
> > >
> > > I thought Geoff said at the time that PPC worked OK without the dummy
> > > weak definition.  What's the actual issue that breaks it?
> >
> > Backwards compatibility? Actually I can't do much better in this area,
> > cause the innards of the shared library loading are still mostly a
> > mystery to me. Maybe it's not possible to have backwards compatibility,
> > maybe the shared lib loader has a bug, maybe...? I think Geoff is the one
> > to ask here, or maybe somebody can give me some hints on what to look
> > next.
>
> I believe it's either a bug in ld.so or a bug in the binutils.
>
> If someone could show me the output of
>
> objdump -R zlib.so | grep gmon_start

the zlib.so compiled against glibc-2.1.3:
[fsirl@enzo:/cvsx/rawhide/zlib-1.1.3]$ objdump -R /usr/lib/libz.so|grep gmon
0001debc R_PPC_JMP_SLOT    __gmon_start__

the zlib.so compiled against glibc-2.1.94:
[fsirl@enzo:/cvsx/rawhide/zlib-1.1.3]$ objdump -R 
../BUILD/zlib-1.1.3/libz.so|grep gmon
0001e994 R_PPC_GLOB_DAT    __gmon_start__

the zlib example compiled against glibc-2.1.94 and 
zlib.so-compiled-against-2.1.3:
[fsirl@enzo:/cvsx/rawhide/zlib-1.1.3]$ objdump -R example|grep gmon
10012ee8 R_PPC_GLOB_DAT    __gmon_start__
10013104 R_PPC_JMP_SLOT    __gmon_start__

And I guess this double relocation is the culprit then?

Franz.