perf jit: Let convert_timestamp() to be backwards-compatible
authorLeo Yan <leo.yan@linaro.org>
Wed, 28 Apr 2021 12:09:13 +0000 (20:09 +0800)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Fri, 14 May 2021 07:50:44 +0000 (09:50 +0200)
commit86941f8bd46ae1ddb41239ab93d0d4959a416260
treea0e56ace83dbf87e82e997dd66b479a76c03187d
parentfe07408afba2b594bcc7d1b636193294d5c7972d
perf jit: Let convert_timestamp() to be backwards-compatible

[ Upstream commit aa616f5a8a2d22a179d5502ebd85045af66fa656 ]

Commit d110162cafc80dad ("perf tsc: Support cap_user_time_short for
event TIME_CONV") supports the extended parameters for event TIME_CONV,
but it broke the backwards compatibility, so any perf data file with old
event format fails to convert timestamp.

This patch introduces a helper event_contains() to check if an event
contains a specific member or not.  For the backwards-compatibility, if
the event size confirms the extended parameters are supported in the
event TIME_CONV, then copies these parameters.

Committer notes:

To make this compiler backwards compatible add this patch:

  -       struct perf_tsc_conversion tc = { 0 };
  +       struct perf_tsc_conversion tc = { .time_shift = 0, };

Fixes: d110162cafc8 ("perf tsc: Support cap_user_time_short for event TIME_CONV")
Signed-off-by: Leo Yan <leo.yan@linaro.org>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Gustavo A. R. Silva <gustavoars@kernel.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steve MacLean <Steve.MacLean@Microsoft.com>
Cc: Yonatan Goldschmidt <yonatan.goldschmidt@granulate.io>
Link: https://lore.kernel.org/r/20210428120915.7123-3-leo.yan@linaro.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
tools/lib/perf/include/perf/event.h
tools/perf/util/jitdump.c