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 E58B4EB64DC for ; Fri, 7 Jul 2023 02:20:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231799AbjGGCUa (ORCPT ); Thu, 6 Jul 2023 22:20:30 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54248 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231732AbjGGCU2 (ORCPT ); Thu, 6 Jul 2023 22:20:28 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D8230170C; Thu, 6 Jul 2023 19:20:24 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 6CBD7614D4; Fri, 7 Jul 2023 02:20:24 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 65888C433C8; Fri, 7 Jul 2023 02:20:23 +0000 (UTC) Date: Thu, 6 Jul 2023 22:20:20 -0400 From: Steven Rostedt To: "Masami Hiramatsu (Google)" Cc: Dan Carpenter , linux-trace-kernel@vger.kernel.org, LKML Subject: Re: [PATCH 3/3] tracing/probes: Fix return value when "(fault)" is injected Message-ID: <20230706222020.6e5c8e89@rorschach.local.home> In-Reply-To: <20230707110210.06e81e182c775454ce86280d@kernel.org> References: <168830922841.2278819.9165254236027770818.stgit@mhiramat.roam.corp.google.com> <168830925534.2278819.7237772177111801959.stgit@mhiramat.roam.corp.google.com> <20230705224956.1c5213e6@gandalf.local.home> <20230706134036.5c074aa5fc6a55cdb5038660@kernel.org> <20230706095039.1cb9c9d1@gandalf.local.home> <20230707110210.06e81e182c775454ce86280d@kernel.org> 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-kernel@vger.kernel.org On Fri, 7 Jul 2023 11:02:10 +0900 Masami Hiramatsu (Google) wrote: > /* Print type function for string type */ > int PRINT_TYPE_FUNC_NAME(string)(struct trace_seq *s, void *data, void *ent) > { > int len = *(u32 *)data >> 16; > > if (!len) > trace_seq_puts(s, "(fault)"); > else > ---- > > In this case, what we need is to set data_loc length = 0 if ret < 0. > > Do you really need to get '"(fault)"' (with double quotation) or > just '(fault)' (no double quotation) is OK? ># echo 'e:myopen syscalls/sys_enter_openat file=+0($filename):ustring' >> /sys/kernel/tracing/dynamic_events ># trace-cmd start -e myopen ># trace-cmd show # tracer: nop # # entries-in-buffer/entries-written: 19/19 #P:4 # # _-----=> irqs-off/BH-disabled # / _----=> need-resched # | / _---=> hardirq/softirq # || / _--=> preempt-depth # ||| / _-=> migrate-disable # |||| / delay # TASK-PID CPU# ||||| TIMESTAMP FUNCTION # | | | ||||| | | trace-cmd-4688 [000] ...1. 466968.015784: myopen: (syscalls.sys_enter_openat) file=(fault) trace-cmd-4688 [000] ...1. 466968.015816: myopen: (syscalls.sys_enter_openat) file=(fault) trace-cmd-4688 [000] ...1. 466968.015833: myopen: (syscalls.sys_enter_openat) file=(fault) trace-cmd-4688 [000] ...1. 466968.015849: myopen: (syscalls.sys_enter_openat) file=(fault) trace-cmd-4688 [000] ...1. 466968.015864: myopen: (syscalls.sys_enter_openat) file=(fault) trace-cmd-4688 [000] ...1. 466968.015879: myopen: (syscalls.sys_enter_openat) file=(fault) Does that answer your question? ;-) -- Steve