This is a note to let you know that I've just added the patch titled
perf script: Skip aggregation for stat events
to the 6.3-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
perf-script-skip-aggregation-for-stat-events.patch
and it can be found in the queue-6.3 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 2fe6575924612f1014a0539ab3053b106aded926 Mon Sep 17 00:00:00 2001
From: Sandipan Das <sandipan.das@xxxxxxx>
Date: Fri, 5 May 2023 15:32:53 +0530
Subject: perf script: Skip aggregation for stat events
From: Sandipan Das <sandipan.das@xxxxxxx>
commit 2fe6575924612f1014a0539ab3053b106aded926 upstream.
The script command does not support aggregation modes by itself although
that can be achieved using post-processing scripts. Because of this, it
does not allocate memory for aggregated event values.
Upon running perf stat record, the aggregation mode is set in the perf
data file. If the mode is AGGR_GLOBAL, the aggregated event values are
accessed and this leads to a segmentation fault since these were never
allocated to begin with. Set the mode to AGGR_NONE explicitly to avoid
this.
E.g.
$ perf stat record -e cycles true
$ perf script
Before:
Segmentation fault (core dumped)
After:
CPU THREAD VAL ENA RUN TIME EVENT
-1 231919 162831 362069 362069 935289 cycles:u
Fixes: 8b76a3188b85724f ("perf stat: Remove unused perf_counts.aggr field")
Signed-off-by: Sandipan Das <sandipan.das@xxxxxxx>
Acked-by: Namhyung Kim <namhyung@xxxxxxxxxx>
Cc: Adrian Hunter <adrian.hunter@xxxxxxxxx>
Cc: Alexander Shishkin <alexander.shishkin@xxxxxxxxxxxxxxx>
Cc: Ananth Narayan <ananth.narayan@xxxxxxx>
Cc: Ian Rogers <irogers@xxxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: Jiri Olsa <jolsa@xxxxxxxxxx>
Cc: Mark Rutland <mark.rutland@xxxxxxx>
Cc: Namhyung Kim <namhyung@xxxxxxxxxx>
Cc: Nick Terrell <terrelln@xxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Ravi Bangoria <ravi.bangoria@xxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx # v6.2+
Link: https://lore.kernel.org/r/83d6c6c05c54bf00c5a9df32ac160718efca0c7a.1683280603.git.sandipan.das@xxxxxxx
Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
tools/perf/builtin-script.c | 7 +++++++
1 file changed, 7 insertions(+)
--- a/tools/perf/builtin-script.c
+++ b/tools/perf/builtin-script.c
@@ -3652,6 +3652,13 @@ static int process_stat_config_event(str
union perf_event *event)
{
perf_event__read_stat_config(&stat_config, &event->stat_config);
+
+ /*
+ * Aggregation modes are not used since post-processing scripts are
+ * supposed to take care of such requirements
+ */
+ stat_config.aggr_mode = AGGR_NONE;
+
return 0;
}
Patches currently in stable-queue which might be from sandipan.das@xxxxxxx are
queue-6.3/perf-script-skip-aggregation-for-stat-events.patch
