This is a note to let you know that I've just added the patch titled perf header: Fix handling of PERF_EVENT_UPDATE__SCALE to the 4.9-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-header-fix-handling-of-perf_event_update__scale.patch and it can be found in the queue-4.9 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From 8434a2ec13d5c8cb25716950bfbf7c9d7b64628a Mon Sep 17 00:00:00 2001 From: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx> Date: Wed, 8 Feb 2017 21:57:22 -0300 Subject: perf header: Fix handling of PERF_EVENT_UPDATE__SCALE From: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx> commit 8434a2ec13d5c8cb25716950bfbf7c9d7b64628a upstream. 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@xxxxxxxxx> Cc: Jiri Olsa <jolsa@xxxxxxxxxx> Cc: Kan Liang <kan.liang@xxxxxxxxx> Cc: Namhyung Kim <namhyung@xxxxxxxxxx> Cc: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx> Fixes: daeecbc0c431 ("perf tools: Add event_update event scale type") Link: http://lkml.kernel.org/n/tip-lukcf9hdj092ax2914ss95at@xxxxxxxxxxxxxx Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- tools/perf/util/header.c | 1 + 1 file changed, 1 insertion(+) --- a/tools/perf/util/header.c +++ b/tools/perf/util/header.c @@ -3184,6 +3184,7 @@ int perf_event__process_event_update(str 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; Patches currently in stable-queue which might be from acme@xxxxxxxxxx are queue-4.9/perf-thread_map-correctly-size-buffer-used-with-dirent-dt_name.patch queue-4.9/perf-tests-avoid-possible-truncation-with-dirent-d_name-snprintf.patch queue-4.9/perf-top-use-__fallthrough.patch queue-4.9/perf-scripting-perl-fix-compile-error-with-some-perl5-versions.patch queue-4.9/perf-bench-numa-avoid-possible-truncation-when-using-snprintf.patch queue-4.9/perf-probe-add-error-checks-to-offline-probe-post-processing.patch queue-4.9/perf-header-fix-handling-of-perf_event_update__scale.patch queue-4.9/tools-string-use-__fallthrough-in-perf_atoll.patch queue-4.9/perf-intel-pt-use-__fallthrough.patch queue-4.9/tools-include-add-a-__fallthrough-statement.patch queue-4.9/tools-strfilter-use-__fallthrough.patch queue-4.9/perf-probe-fix-to-probe-on-gcc-generated-symbols-for-offline-kernel.patch