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 X-Spam-Level: X-Spam-Status: No, score=-5.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_2 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 4767EC48BCF for ; Wed, 9 Jun 2021 11:07:20 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 24D1C6139A for ; Wed, 9 Jun 2021 11:07:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232750AbhFILJN (ORCPT ); Wed, 9 Jun 2021 07:09:13 -0400 Received: from mail.kernel.org ([198.145.29.99]:33076 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238062AbhFILJM (ORCPT ); Wed, 9 Jun 2021 07:09:12 -0400 Received: from gandalf.local.home (cpe-66-24-58-225.stny.res.rr.com [66.24.58.225]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 3171A61364; Wed, 9 Jun 2021 11:07:18 +0000 (UTC) Date: Wed, 9 Jun 2021 07:07:16 -0400 From: Steven Rostedt To: Julia Lawall Cc: Linux Trace Devel Subject: Re: [PATCH v2] libtraceevent: Handle parsing of "(REC)->" case Message-ID: <20210609070716.5f7d4a4e@gandalf.local.home> In-Reply-To: References: <20210608172744.796e93b7@gandalf.local.home> 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-devel@vger.kernel.org On Wed, 9 Jun 2021 07:43:08 +0200 (CEST) Julia Lawall wrote: > > If a trace event wraps the special __entry variable to dereference it with > > parenthesis, it shows up in the trace event format file wrapping the > > "(REC)" as well. For example, the "func_repeats" event passed the __entry > > into a helper macro in the TP_printk() portion, and the macro correctly > > wrapped its parameter in parenthesis. This caused the output to show: > > > > "(((u64)(REC)->top_delta_ts << 32) | (REC)->bottom_delta_ts)" > > > > The parser then failed to parse the "(REC)->" portion, as it expected the > > "->" to appear directly after the "REC". This is not a requirement, and > > the parser should be able to handle such cases. > > > > When this occurred, trace-cmd would error with the following message: > > > > trace-cmd: No such file or directory > > Error: expected type 4 but read 5 > > For the record, I have tried tracing two programs with Linux v5.13-rc4 or > rc5 and both of them had this problem, while they didn't have this problem > when traced with the same arguments with earlier Linux versions. So it > may be systematic for Linux v5.13. The event mentioned in the change log was added in 5.13. But it is a valid pattern, and not a bug in the 5.13 kernel. -- Steve