perf sched: Suppress latency table output when trace samples are missing

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When 'perf sched latency' is executed on a perf.data file that lacks
tracepoint samples (i.e., a file recorded without the -R flag or
containing only non-tracepoint events), perf_session__has_traces()
correctly outputs an error message. However, perf_sched__read_events()
subsequently falls through and returns 0 (success).

Consequently, caller functions such as perf_sched__lat() assume event
processing succeeded and proceed to render empty latency header tables
and total summary statistics.

Fix this behaviour by ensuring perf_sched__read_events() aborts early and
returns a suitable error code when perf_session__has_traces() evaluates
to false.

Additionally, validate thread__get_runtime() against NULL in
map_switch_event() to prevent potential null-pointer dereferences.

Fixes: 27295592c2 ("perf session: Share the common trace sample_check routine as perf_session__has_traces")
Reviewed-by: Ian Rogers <irogers@google.com>
Signed-off-by: Aaron Tomlin <atomlin@atomlin.com>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>

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Aaron Tomlin 2026-08-06 11:39:23 -04:00 • committed by Namhyung Kim

parent 006a6f0f6e

commit 4a81d59a9d

1 changed files with 12 additions and 11 deletions

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tools/perf/builtin-sched.c

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