Re: [PATCH 01/52] perf tools: Fix jump label always changing during tracing

Peter Zijlstra
2014-07-23T06:58:33Z

On Wed, Jul 23, 2014 at 09:07:32AM +0300, Adrian Hunter wrote:
> On 07/22/2014 05:11 PM, Peter Zijlstra wrote:
> > On Tue, Jul 22, 2014 at 11:00:34AM -0300, Arnaldo Carvalho de Melo wrote:
> >> Em Tue, Jul 22, 2014 at 04:17:10PM +0300, Adrian Hunter escreveu:
> >>> Intel PT decoding walks the object code to reconstruct
> >>> the trace. A jump label change during tracing causes
> >>> decoding errors.
> >
> > You'd better fix that, jump_labels can change any time and they're all
> > over the frigging place.
> >
>
> Perhaps a general method is needed to be able to deal with kernel
> self-modifying code.

I know people are looking at doing the same to userspace, is that also a
problem?