perf: Fix inherited events vs. tracepoint filters

commit b71b437eedaed985062492565d9d421d975ae845 upstream.

Arnaldo reported that tracepoint filters seem to misbehave (ie. not
apply) on inherited events.

The fix is obvious; filters are only set on the actual (parent)
event, use the normal pattern of using this parent event for filters.
This is safe because each child event has a reference to it.

Reported-by: Arnaldo Carvalho de Melo <acme@kernel.org>
Tested-by: Arnaldo Carvalho de Melo <acme@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frédéric Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/r/20151102095051.GN17308@twins.programming.kicks-ass.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

diff --git a/kernel/events/core.c b/kernel/events/core.c
index f475286..7c0b4f0 100644 (file)
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -5393,6 +5393,10 @@ static int perf_tp_filter_match(struct perf_event *event,
 {
        void *record = data->raw->data;
 
 {
        void *record = data->raw->data;
 

+       /* only top level events have filters set */
+       if (event->parent)
+               event = event->parent;
+

        if (likely(!event->filter) || filter_match_preds(event->filter, record))
                return 1;
        return 0;
        if (likely(!event->filter) || filter_match_preds(event->filter, record))
                return 1;
        return 0;