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perf header: Fix handling of PERF_EVENT_UPDATE__SCALE

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In commit daeecbc0c4 ("perf tools: Add event_update event scale type"), the
handling of PERF_EVENT_UPDATE__SCALE cast struct event_update_event->data to a
pointer to event_update_event_scale, uses some field from this casted struct
and then ends up falling through to the handling of another event type,
PERF_EVENT_UPDATE__CPUS were it casts that ev->data to yet another type, oops,
fix it by inserting the missing break.

Noticed when building perf using gcc 7 on Fedora Rawhide:

  util/header.c: In function 'perf_event__process_event_update':
  util/header.c:3207:16: error: this statement may fall through [-Werror=implicit-fallthrough=]
     evsel->scale = ev_scale->scale;
     ~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~
  util/header.c:3208:2: note: here
    case PERF_EVENT_UPDATE__CPUS:
    ^~~~

This wasn't noticed because probably PERF_EVENT_UPDATE__CPUS comes after
PERF_EVENT_UPDATE__SCALE, so we would just create a bogus evsel->own_cpus when
processing a PERF_EVENT_UPDATE__SCALE to then leak it and create a new cpu map
with the correct data.

Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kan Liang <kan.liang@intel.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Fixes: daeecbc0c4 ("perf tools: Add event_update event scale type")
Link: http://lkml.kernel.org/n/tip-lukcf9hdj092ax2914ss95at@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
This commit is contained in:
Arnaldo Carvalho de Melo 2017-02-08 21:57:22 -03:00
parent bdf23a9a19
commit 8434a2ec13
1 changed files with 1 additions and 0 deletions
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tools/perf/util/header.c
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@ -3205,6 +3205,7 @@ int perf_event__process_event_update(struct perf_tool *tool __maybe_unused,
case PERF_EVENT_UPDATE__SCALE:
ev_scale = (struct event_update_event_scale *) ev->data;
evsel->scale = ev_scale->scale;
break;
case PERF_EVENT_UPDATE__CPUS:
ev_cpus = (struct event_update_event_cpus *) ev->data;