On 09/03, Oleg Nesterov wrote:
>
> This is another reason to move enable/disable step into ptrace_stop().
> And in fact I had the patches a loong ago, but we need to cleanup
> the usage of PT_SINGLESTEP/PT_BLOCKSTEP first. The tracer should
> simply set/clear these PT_ flags and resume the tracee which should
> check them and do user_*_single_step() in response.

Found these patches, see the attachments.... And this also fixes the
problems with DEBUGCTLMSR_BTF.

The patches should be re-diffed, but I need to recall why I didn't
send them, perhaps I noticed some problem...

Oleg.