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 int __perf_event_enable(void *info)
{
	struct perf_event *event = info;
	struct perf_event_context *ctx = event->ctx;
	struct perf_event *leader = event->group_leader;
	struct perf_cpu_context *cpuctx = __get_cpu_context(ctx);
	int err;

	if (WARN_ON_ONCE(!ctx->is_active))
		return -EINVAL;

	raw_spin_lock(&ctx->lock);
	update_context_time(ctx);

	if (event->state >= PERF_EVENT_STATE_INACTIVE)
		goto unlock;

	/*
	 * set current task's cgroup time reference point
	 */
	perf_cgroup_set_timestamp(current, ctx);

	__perf_event_mark_enabled(event);

	if (!event_filter_match(event)) {
		if (is_cgroup_event(event))
			perf_cgroup_defer_enabled(event);
		goto unlock;
	}

	/*
	 * If the event is in a group and isn't the group leader,
	 * then don't put it on unless the group is on.
	 */
	if (leader != event && leader->state != PERF_EVENT_STATE_ACTIVE)
		goto unlock;

	if (!group_can_go_on(event, cpuctx, 1)) {
		err = -EEXIST;
	} else {
		if (event == leader)
			err = group_sched_in(event, cpuctx, ctx);
		else
			err = event_sched_in(event, cpuctx, ctx);
	}

	if (err) {
		/*
		 * If this event can't go on and it's part of a
		 * group, then the whole group has to come off.
		 */
		if (leader != event)
			group_sched_out(leader, cpuctx, ctx);
		if (leader->attr.pinned) {
			update_group_times(leader);
			leader->state = PERF_EVENT_STATE_ERROR;
		}
	}

unlock:
	raw_spin_unlock(&ctx->lock);

	return 0;
}

static int __perf_event_enable(void *info)
{
	struct perf_event *event = info;
	struct perf_event_context *ctx = event->ctx;
	struct perf_event *leader = event->group_leader;
	struct perf_cpu_context *cpuctx = __get_cpu_context(ctx);
	int err;

	if (WARN_ON_ONCE(!ctx->is_active))
		return -EINVAL;

	raw_spin_lock(&ctx->lock);
	update_context_time(ctx);

	if (event->state >= PERF_EVENT_STATE_INACTIVE)
		goto unlock;

	/*
	 * set current task's cgroup time reference point
	 */
	perf_cgroup_set_timestamp(current, ctx);

	__perf_event_mark_enabled(event);

	if (!event_filter_match(event)) {
		if (is_cgroup_event(event))
			perf_cgroup_defer_enabled(event);
		goto unlock;
	}

	/*
	 * If the event is in a group and isn't the group leader,
	 * then don't put it on unless the group is on.
	 */
	if (leader != event && leader->state != PERF_EVENT_STATE_ACTIVE)
		goto unlock;

	if (!group_can_go_on(event, cpuctx, 1)) {
		err = -EEXIST;
	} else {
		if (event == leader)
			err = group_sched_in(event, cpuctx, ctx);
		else
			err = event_sched_in(event, cpuctx, ctx);
	}

	if (err) {
		/*
		 * If this event can't go on and it's part of a
		 * group, then the whole group has to come off.
		 */
		if (leader != event)
			group_sched_out(leader, cpuctx, ctx);
		if (leader->attr.pinned) {
			update_group_times(leader);
			leader->state = PERF_EVENT_STATE_ERROR;
		}
	}

unlock:
	raw_spin_unlock(&ctx->lock);

	return 0;
}
