[PATCH 0/4] perf cs-etm: Track exception level
Arnaldo Carvalho de Melo
acme at kernel.org
Mon Jun 5 12:44:45 PDT 2023
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
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