The id field of struct ftrace_event_call is different for kernels: Old kernel uses ftrace_event_call.id newer kernel uses ftrace_event_call.event.type Change ftrace_get_event_type_id() and make it serves for different kernels. Signed-off-by: Lai Jiangshan <laijs(a)cn.fujitsu.com&gt; --- diff --git a/extensions/trace.c b/extensions/trace.c index 3697108..1ad53c1 100755 --- a/extensions/trace.c +++ b/extensions/trace.c @@ -878,6 +878,15 @@ int ftrace_get_event_type_id(ulong call, int *id) if (!inited) { inited = 1; id_offset = MEMBER_OFFSET("ftrace_event_call", "id"); + + if (id_offset < 0) { + /* id = call->event.type */ + int f1 = MEMBER_OFFSET("ftrace_event_call", "event"); + int f2 = MEMBER_OFFSET("trace_event", "type"); + + if (f1 >= 0 && f2 >= 0) + id_offset = f1 + f2; + } } if (id_offset < 0)