On Mon, 02 Jun 2008 11:09:56 +0200, Renzo Davoli wrote: > Jan Kratochvil has just sent me an E-mail saying that it seems to be > a kvm bug (or a bug caused by kvm).
KVM bug details at https://bugzilla.redhat.com/show_bug.cgi?id=437028 . > 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... Just FYI on 2.6.25 I still get the crash, host: kernel: kvm: 19661: cpu0 unhandled wrmsr: 0x1d9 data 2 kernel-2.6.25.3-18.fc9.x86_64 kvm-65-7.fc9.x86_64 guest: vanilla 2.6.25 x86_64 Pid: 1945, comm: block-step Not tainted 2.6.25-0.101.rc4.git3.fc8 #1 RIP: 0010:[<ffffffff8100ab79>] [<ffffffff8100ab79>] __switch_to+0x218/0x2bc (the version number is for a RPM-built vanilla kernel) (I did not find any ptrace patches in between 2.6.25 and 2.6.25.4.) Regards, Jan