From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 1AFF8C7EE2D for ; Mon, 22 May 2023 14:32:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231609AbjEVOc3 (ORCPT ); Mon, 22 May 2023 10:32:29 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56464 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233644AbjEVOc2 (ORCPT ); Mon, 22 May 2023 10:32:28 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E5D5399; Mon, 22 May 2023 07:32:27 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 83940613F7; Mon, 22 May 2023 14:32:27 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 85AB2C433EF; Mon, 22 May 2023 14:32:26 +0000 (UTC) Date: Mon, 22 May 2023 10:32:24 -0400 From: Steven Rostedt To: sunliming Cc: mhiramat@kernel.org, linux-trace-kernel@vger.kernel.org, linux-kernel@vger.kernel.org, Beau Belgrave Subject: Re: [PATCH] racing/user_events: Prevent same address and bit per process Message-ID: <20230522103224.032ec78f@rorschach.local.home> In-Reply-To: <20230519081035.228891-1-sunliming@kylinos.cn> References: <20230519081035.228891-1-sunliming@kylinos.cn> X-Mailer: Claws Mail 3.17.8 (GTK+ 2.24.33; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-trace-kernel@vger.kernel.org Is the subject a Freudian slip? Added Beau. I need to add him to the maintainers file for user events ;-) On Fri, 19 May 2023 16:10:35 +0800 sunliming wrote: > User processes register name_args for events. If the same name are registered > multiple times in the same process, it can cause undefined behavior. Because > the same name may be used for a diffrent event. If this event has the same > format as the original event, it is impossible to distinguish the trace output > of these two events. If the event has a different format from the original event, > the trace output of the new event is incorrect. > > Return EADDRINUSE back to the user process if the same event has being registered > in the same process. I'll let Beau ack this or not. -- Steve > > Signed-off-by: sunliming > --- > kernel/trace/trace_events_user.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/kernel/trace/trace_events_user.c b/kernel/trace/trace_events_user.c > index b1ecd7677642..4ef6bdb5c07c 100644 > --- a/kernel/trace/trace_events_user.c > +++ b/kernel/trace/trace_events_user.c > @@ -1996,7 +1996,7 @@ static int user_events_ref_add(struct user_event_file_info *info, > > for (i = 0; i < count; ++i) > if (refs->events[i] == user) > - return i; > + return -EADDRINUSE; > } > > size = struct_size(refs, events, count + 1);