lkml.org 
[lkml]   [2017]   [Feb]   [10]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
Date
From
Subject[tip:perf/core] perf header: Fix handling of PERF_EVENT_UPDATE__SCALE
Commit-ID:  8434a2ec13d5c8cb25716950bfbf7c9d7b64628a
Gitweb: http://git.kernel.org/tip/8434a2ec13d5c8cb25716950bfbf7c9d7b64628a
Author: Arnaldo Carvalho de Melo <acme@redhat.com>
AuthorDate: Wed, 8 Feb 2017 21:57:22 -0300
Committer: Arnaldo Carvalho de Melo <acme@redhat.com>
CommitDate: Wed, 8 Feb 2017 22:06:18 -0300

perf header: Fix handling of PERF_EVENT_UPDATE__SCALE

In commit daeecbc0c431 ("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: daeecbc0c431 ("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>
---
tools/perf/util/header.c | 1 +
1 file changed, 1 insertion(+)

diff --git a/tools/perf/util/header.c b/tools/perf/util/header.c
index c567d9f..3d12c16 100644
--- a/tools/perf/util/header.c
+++ b/tools/perf/util/header.c
@@ -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;

\
 
 \ /
  Last update: 2017-02-10 08:57    [W:0.161 / U:0.016 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site