[Gcl-devel] Re: gcl-2.6.7 and FC4

[Juho Snellman]

<address@hidden> wrote:
> GCL-2.6.7 fails to build on FC4.
> I'm trying to debug it now but I thought I'd mention it in case
> anyone already knows why.

FC4 randomizes the brk (and a bunch of other memory regions) more
agressively than the exec-shield patches in previous Fedora kernels.
Also the old methods of marking the executable as non-randomizable
don't work any more. To test whether this is the reason, try building
under setarch ("setarch i386 -R make"). 

The only working method of disabling the randomization seems to be
doing something like this at startup:

    {
       long pers = personality(-1);
       /* 0x40000 aka. ADDR_NO_RANDOMIZE */
       if (!(pers & 0x40000)) {
           personality(pers | 0x40000);
           execve(argv[0], argv, envp);
       }
    }   

See the sbcl-devel thread "Memory randomization problems coming" for
some more information on this.

-- 
Juho Snellman