Re: [PATCH v2 4/4] uprobes/powerpc: Make use of generic routinesto enable single step

[Suzuki K. Poulose]

On 12/15/2012 01:32 AM, Oleg Nesterov wrote:
> On 12/03, Suzuki K. Poulose wrote:
> > Replace the ptrace helpers with the powerpc generic routines to
> > enable/disable single step. We save/restore the MSR (and DCBR for BookE)
> > across for the operation. We don't have to disable the single step,
> > as restoring the MSR/DBCR would restore the previous state.
>
> Obviously I can't review this series (although it looks fine to me).
>
> Just one note,
>
> > @@ -121,7 +132,7 @@ int arch_uprobe_post_xol(struct arch_uprobe *auprobe, struct pt_regs *regs)
> >
> >   	WARN_ON_ONCE(current->thread.trap_nr != UPROBE_TRAP_NR);
> >
> > -	uprobe_restore_context_sstep(&utask->autask);
> > +	uprobe_restore_context_sstep(&utask->autask, regs);
>
> I am not sure ppc needs this, but note that x86 does a bit more.
>
> Not only we need to restore the "single-step" state, we need to
> send SIGTRAP if it was not set by us. The same for _skip_sstep.
Ok. I will investigate that part and do the necessary.

Thanks
Suzuki

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