perf events: Fix event inherit fallout of precalculated headers

The precalculated header size is not updated when an event is inherited. That
results in bogus sample entries for all child events. Bug introduced in c320c7b.

Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ian Munsie <imunsie@au1.ibm.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Stephane Eranian <eranian@google.com>
LKML-Reference: <alpine.LFD.2.00.1012031245220.2653@localhost6.localdomain6>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

diff --git a/kernel/perf_event.c b/kernel/perf_event.c
index aede71245e9f9594a47a4165787f2485ba530f1d..7961b27aceead89e6e75f3f7aa00d8383569bec2 100644 (file)
--- a/kernel/perf_event.c
+++ b/kernel/perf_event.c
@@ -6098,6 +6098,11 @@ inherit_event(struct perf_event *parent_event,
        child_event->ctx = child_ctx;
        child_event->overflow_handler = parent_event->overflow_handler;
 
+       /*
+        * Precalculate sample_data sizes
+        */
+       perf_event__header_size(child_event);
+
        /*
         * Link it up in the child's context:
         */