Got it: glibc 2.3.5 and gcc-4.0 4.0.3-6

[Petr Salinger]

> > >Meanwhile, I made some progress on this bug (even if I have no time...). 
> > >It seems that the problem comes from brk.o, as using the one generated 
> > >with 4.0.2-6 in the tree built with 4.0.2-5 reproduces the problem. The 
> > >reverse is also true, ie copying brk.o built with 4.0.2-5 to the tree 
> > >built with 4.0.2-6 fixes the problem.
> > >
> > You're right, the problem comes from the optimisation. Building brk.c 
> > with -mtune=i486 fixes the problem, both for -march=i386 and 
> > -march=i486. Now the question is about the C code being correct or not...

The C code is correct, the our asm is not.

The (years standing) problem is in syscall.S 
I will fix it shortly.

Aurelien, many thanks for invaluable hint on brk.c. 

Petr