x86_64: fix 2.6.18 regression - PTRACE_OLDSETOPTIONS should be accepted

x86_64: fix 2.6.18 regression - PTRACE_OLDSETOPTIONS should be accepted

Also PTRACE_OLDSETOPTIONS should be accepted, as done by kernel/ptrace.c and
forced by binary compatibility. UML/32bit breaks because of this - since it is wise
enough to use PTRACE_OLDSETOPTIONS to be binary compatible with 2.4 host
kernels.

Until 2.6.17 (commit f0f2d6536e3515b5b1b7ae97dc8f176860c8c2ce) we had:

       default:
                return sys_ptrace(request, pid, addr, data);

Instead here we have:
        case PTRACE_GET_THREAD_AREA:
	case ...:
                return sys_ptrace(request, pid, addr, data);

        default:
                return -EINVAL;

This change was a style change - when a case is added, it must be explicitly
tested this way. In this case, not enough testing was done.

Cc: Andi Kleen <ak@suse.de>
Signed-off-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>