Re: [PATCH 0/4] perf cs-etm: Track exception level

[Arnaldo Carvalho de Melo]

Em Wed, May 24, 2023 at 02:19:54PM +0100, James Clark escreveu:
> Some fixes to support an issue reported by Denis Nikitin where decoding
> trace that contains different EL1 and EL2 kernels can crash or go into
> an infinite loop because the wrong kernel maps are used for the decode.
> 
> This still doesn't support distinguishing guest and host userspace,
> we'd still have to fix the timestamps and do a bit more work to
> correlate that. And I've removed PERF_RECORD_MISC_HYPERVISOR as a
> possible outcome of cs_etm__cpu_mode(). As far as I know this could
> never have been returned anyway because machine__is_host(machine) was
> always true due to session.machines.host being hard coded. And I'm not
> sure of the relevance of the difference between PERF_RECORD_MISC_KERNEL
> and PERF_RECORD_MISC_HYPERVISOR in this scenario.
> 
> The first commit is a tidy up, second fixes a bug that I found when
> comparing the exception level and thread of branch records, the third
> is the main fix, and the last commit is some extra error checking. 
> 
> Applies to acme/perf-tools (4e111f0cf0)

So there seems to be agreement the first two patches can be applied? May
I go ahead and do that now?

- Arnaldo
 
> James Clark (4):
>   perf cs-etm: Only track threads instead of PID and TIDs
>   perf cs-etm: Use previous thread for branch sample source IP
>   perf cs-etm: Track exception level
>   perf cs-etm: Add exception level consistency check
> 
>  .../perf/util/cs-etm-decoder/cs-etm-decoder.c |  13 +-
>  .../perf/util/cs-etm-decoder/cs-etm-decoder.h |   4 +-
>  tools/perf/util/cs-etm.c                      | 220 +++++++++---------
>  tools/perf/util/cs-etm.h                      |   5 +-
>  4 files changed, 126 insertions(+), 116 deletions(-)
> 
> -- 
> 2.34.1
> 

-- 

- Arnaldo