Jan Kratochvil has just sent me an E-mail saying that it seems to be
a kvm bug (or a bug caused by kvm).
He is right: using qemu/kqemu instead of kvm it does not panic.
Anyway I am puzzled. Using kvm the PTRACE_SINGLEBLOCK should have the
same effect on 2.6.25.4 and 2.6.25.4+utrace.
2.6.25.4: ptrace_resume(kernel/ptrace.c)->user_enable_block_step
2.6.25.4+utrace:
ptrace_common(kernel/ptrace.c) sets UTRACE_ACTION_BLOCKSTEP
->utrace_quiescent(kernel/utrace.c) tests UTRACE_ACTION_BLOCKSTEP
->user_enable_block_step
I wonder where is the difference...
Anyway, let us wait for kvm people to fix it...
I want to thank Jan for his quick feedback.
renzo
