perf: Treat attr.config as u64 in perf_swevent_init()

Trinity discovered that we fail to check all 64 bits of
attr.config passed by user space, resulting to out-of-bounds
access of the perf_swevent_enabled array in
sw_perf_event_destroy().

Introduced in commit b0a873ebb ("perf: Register PMU
implementations").

Signed-off-by: Tommi Rantala <tt.rantala@gmail.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: davej@redhat.com
Cc: Paul Mackerras <paulus@samba.org>
Cc: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
Link: http://lkml.kernel.org/r/1365882554-30259-1-git-send-email-tt.rantala@gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
static void perf_output_read(struct perf_output_handle *handle,
			     struct perf_event *event)
{
	u64 enabled = 0, running = 0, now;
	u64 read_format = event->attr.read_format;

	/*
	 * compute total_time_enabled, total_time_running
	 * based on snapshot values taken when the event
	 * was last scheduled in.
	 *
	 * we cannot simply called update_context_time()
	 * because of locking issue as we are called in
	 * NMI context
	 */
	if (read_format & PERF_FORMAT_TOTAL_TIMES)
		calc_timer_values(event, &now, &enabled, &running);

	if (event->attr.read_format & PERF_FORMAT_GROUP)
		perf_output_read_group(handle, event, enabled, running);
	else
		perf_output_read_one(handle, event, enabled, running);
}

static void perf_output_read(struct perf_output_handle *handle,
			     struct perf_event *event)
{
	u64 enabled = 0, running = 0, now;
	u64 read_format = event->attr.read_format;

	/*
	 * compute total_time_enabled, total_time_running
	 * based on snapshot values taken when the event
	 * was last scheduled in.
	 *
	 * we cannot simply called update_context_time()
	 * because of locking issue as we are called in
	 * NMI context
	 */
	if (read_format & PERF_FORMAT_TOTAL_TIMES)
		calc_timer_values(event, &now, &enabled, &running);

	if (event->attr.read_format & PERF_FORMAT_GROUP)
		perf_output_read_group(handle, event, enabled, running);
	else
		perf_output_read_one(handle, event, enabled, running);
}
