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 62845C47094 for ; Thu, 10 Jun 2021 17:33:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 41FD4613E9 for ; Thu, 10 Jun 2021 17:33:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230251AbhFJRfp (ORCPT ); Thu, 10 Jun 2021 13:35:45 -0400 Received: from mail.kernel.org ([198.145.29.99]:39378 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229802AbhFJRfo (ORCPT ); Thu, 10 Jun 2021 13:35:44 -0400 Received: from oasis.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 EB18A613D0; Thu, 10 Jun 2021 17:33:47 +0000 (UTC) Date: Thu, 10 Jun 2021 13:33:46 -0400 From: Steven Rostedt To: Masami Hiramatsu Cc: "Naveen N. Rao" , , Peter Zijlstra , "Aneesh Kumar K.V" Subject: Re: [PATCH] kprobes: Print an error if probe is rejected Message-ID: <20210610133346.4a55c60a@oasis.local.home> In-Reply-To: <20210610191643.d24e7d56d102567070fe8386@kernel.org> References: <20210610085617.1590138-1-naveen.n.rao@linux.vnet.ibm.com> <20210610191643.d24e7d56d102567070fe8386@kernel.org> X-Mailer: Claws Mail 3.17.3 (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 Thu, 10 Jun 2021 19:16:43 +0900 Masami Hiramatsu wrote: > Hmm, Nack for this way, but I understand that is a problem. > If you got the error in perf probe, which uses ftrace dynamic-event interface. > In that case, the errors should not be output in the dmesg, but are reported > via error_log in tracefs. > And kprobes itself should return different error code to the caller, instead > of printing error in dmesg. See below. We should update perf to use libtracefs that also has an interface to read the error_log file. -- Steve