Re: [PATCH 1/2] perf cs-etm: Fix corrupt data after perf inject from

Leo Yan
2020-09-02T00:41:07Z

Hi Arnaldo,

On Tue, Sep 01, 2020 at 11:54:32AM -0300, Arnaldo Carvalho de Melo wrote:
> Em Mon, Aug 31, 2020 at 08:04:32AM +0800, Leo Yan escreveu:
> > Hi Mathieu,
> >
> > On Thu, Aug 27, 2020 at 02:53:54PM -0600, Mathieu Poirier wrote:
> > > Hi Leo and Al,
> > >
> > > On Wed, Aug 19, 2020 at 04:47:50PM +0800, Leo Yan wrote:
> > > > From: Al Grant <al.grant@arm.com>
> > > >
> > > > Commit 42bbabed09ce ("perf tools: Add hw_idx in struct branch_stack")
> > > > changed the format of branch stacks in perf samples. When samples use
> > > > this new format, a flag must be set in the corresponding event.
> > > > Synthesized branch stacks generated from CoreSight ETM trace were using
> > > > the new format, but not setting the event attribute, leading to
> > > > consumers seeing corrupt data. This patch fixes the issue by setting the
> > > > event attribute to indicate use of the new format.
> > > >
> > > > Fixes: 42bbabed09ce ("perf tools: Add hw_idx in struct branch_stack")
> > > > Signed-off-by: Al Grant <al.grant@arm.com>
> > > > Reviewed-by: Andrea Brunato <andrea.brunato@arm.com>
> > > > Signed-off-by: Leo Yan <leo.yan@linaro.org>
> > > > ---
> > > > tools/perf/util/cs-etm.c | 9 ++++++++-
> > > > 1 file changed, 8 insertions(+), 1 deletion(-)
> > > >
> > > > diff --git a/tools/perf/util/cs-etm.c b/tools/perf/util/cs-etm.c
> > > > index c283223fb31f..a2a369e2fbb6 100644
> > > > --- a/tools/perf/util/cs-etm.c
> > > > +++ b/tools/perf/util/cs-etm.c
> > > > @@ -1344,8 +1344,15 @@ static int cs_etm__synth_events(struct cs_etm_auxtrace *etm,
> > > > attr.sample_type &= ~(u64)PERF_SAMPLE_ADDR;
> > > > }
> > > >
> > > > - if (etm->synth_opts.last_branch)
> > > > + if (etm->synth_opts.last_branch) {
> > > > attr.sample_type |= PERF_SAMPLE_BRANCH_STACK;
> > > > + /*
> > > > + * We don't use the hardware index, but the sample generation
> > > > + * code uses the new format branch_stack with this field,
> > > > + * so the event attributes must indicate that it's present.
> > > > + */
> > > > + attr.branch_sample_type |= PERF_SAMPLE_BRANCH_HW_INDEX;
> > > > + }
> > >
> > > I've see this patch before... I thought it had been merged - what happened?
> >
> > This patch before has been sent by Al to CoreSight mailing list but has
> > not sent to LKML, this is why I resent it to LKML in case it's missed.
>
> So, was it Acked on the CoreSight mailing list? Are we missing any
> Acked-by or Reviewed-by for this 1/2 patch as we got for 2/2?

The CoreSight mailing list has some discussion for this patch set,
when respin this patch set, I confirmed we don't miss any 'Acked' or
'Reviewed' tags.

Thanks,
Leo