This is a note to let you know that I've just added the patch titled perf parse-events: Use strcmp() to compare the PMU name to the 5.4-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-parse-events-use-strcmp-to-compare-the-pmu-name.patch and it can be found in the queue-5.4 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit cee449e56a54c14b0cb130d611c463815462bb59 Author: Jin Yao <yao.jin@xxxxxxxxxxxxxxx> Date: Thu Apr 30 08:36:18 2020 +0800 perf parse-events: Use strcmp() to compare the PMU name [ Upstream commit 8510895bafdbf7c4dd24c22946d925691135c2b2 ] A big uncore event group is split into multiple small groups which only include the uncore events from the same PMU. This has been supported in the commit 3cdc5c2cb924a ("perf parse-events: Handle uncore event aliases in small groups properly"). If the event's PMU name starts to repeat, it must be a new event. That can be used to distinguish the leader from other members. But now it only compares the pointer of pmu_name (leader->pmu_name == evsel->pmu_name). If we use "perf stat -M LLC_MISSES.PCIE_WRITE -a" on cascadelakex, the event list is: evsel->name evsel->pmu_name --------------------------------------------------------------- unc_iio_data_req_of_cpu.mem_write.part0 uncore_iio_4 (as leader) unc_iio_data_req_of_cpu.mem_write.part0 uncore_iio_2 unc_iio_data_req_of_cpu.mem_write.part0 uncore_iio_0 unc_iio_data_req_of_cpu.mem_write.part0 uncore_iio_5 unc_iio_data_req_of_cpu.mem_write.part0 uncore_iio_3 unc_iio_data_req_of_cpu.mem_write.part0 uncore_iio_1 unc_iio_data_req_of_cpu.mem_write.part1 uncore_iio_4 ...... For the event "unc_iio_data_req_of_cpu.mem_write.part1" with "uncore_iio_4", it should be the event from PMU "uncore_iio_4". It's not a new leader for this PMU. But if we use "(leader->pmu_name == evsel->pmu_name)", the check would be failed and the event is stored to leaders[] as a new PMU leader. So this patch uses strcmp to compare the PMU name between events. Fixes: d4953f7ef1a2 ("perf parse-events: Fix 3 use after frees found with clang ASAN") Signed-off-by: Jin Yao <yao.jin@xxxxxxxxxxxxxxx> Acked-by: Jiri Olsa <jolsa@xxxxxxxxxx> Cc: Alexander Shishkin <alexander.shishkin@xxxxxxxxxxxxxxx> Cc: Andi Kleen <ak@xxxxxxxxxxxxxxx> Cc: Jin Yao <yao.jin@xxxxxxxxx> Cc: Kan Liang <kan.liang@xxxxxxxxxxxxxxx> Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx> Link: http://lore.kernel.org/lkml/20200430003618.17002-1-yao.jin@xxxxxxxxxxxxxxx Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/tools/perf/util/parse-events.c b/tools/perf/util/parse-events.c index ca9006cd4bf18..c8924a2039e3c 100644 --- a/tools/perf/util/parse-events.c +++ b/tools/perf/util/parse-events.c @@ -1507,12 +1507,11 @@ parse_events__set_leader_for_uncore_aliase(char *name, struct list_head *list, * event. That can be used to distinguish the leader from * other members, even they have the same event name. */ - if ((leader != evsel) && (leader->pmu_name == evsel->pmu_name)) { + if ((leader != evsel) && + !strcmp(leader->pmu_name, evsel->pmu_name)) { is_leader = false; continue; } - /* The name is always alias name */ - WARN_ON(strcmp(leader->name, evsel->name)); /* Store the leader event for each PMU */ leaders[nr_pmu++] = (uintptr_t) evsel;