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=-1.1 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,MAILING_LIST_MULTI,SPF_PASS,T_DKIMWL_WL_HIGH,URIBL_BLOCKED autolearn=ham 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 CE23FECDFAA for ; Fri, 13 Jul 2018 02:53:08 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 7D1AC214C2 for ; Fri, 13 Jul 2018 02:53:08 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="vcajbfaQ" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 7D1AC214C2 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387747AbeGMDFf (ORCPT ); Thu, 12 Jul 2018 23:05:35 -0400 Received: from mail.kernel.org ([198.145.29.99]:43204 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2387677AbeGMDFf (ORCPT ); Thu, 12 Jul 2018 23:05:35 -0400 Received: from devnote (unknown [180.57.129.245]) (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 A104D2147E; Fri, 13 Jul 2018 02:53:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1531450386; bh=oYYSyUlDi7zkLZbYJC0ngVr4cb6ZyS5f+8FwsS1JUs4=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=vcajbfaQDCfS2f9+vUNBDGGe1wm3ecwyVKt5PInOPH5sjZmQn5ZerRIF5RN9vDarz Npji2XoYtcWx5nrlCYmTnGcon/N2vjzlWzYKn9T2ZH9GgVEuBh1An+o7TX2kW7zPsj CMUb3Y0FSeBIxWtTsTzL6VLYg9ya1XJy/Mr5b54k= Date: Fri, 13 Jul 2018 11:53:01 +0900 From: Masami Hiramatsu To: Francis Deslauriers Cc: rostedt@goodmis.org, peterz@infradead.org, mathieu.desnoyers@efficios.com, linux-kernel@vger.kernel.org Subject: Re: [PATCH 1/2] tracing: kprobes: Prohibit probing on notrace functions Message-Id: <20180713115301.532ab1484e8b0befd90782d0@kernel.org> In-Reply-To: <1531418053-21414-2-git-send-email-francis.deslauriers@efficios.com> References: <1500044315-9508-3-git-send-email-francis.deslauriers@efficios.com> <1531418053-21414-1-git-send-email-francis.deslauriers@efficios.com> <1531418053-21414-2-git-send-email-francis.deslauriers@efficios.com> X-Mailer: Sylpheed 3.5.0 (GTK+ 2.24.30; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 12 Jul 2018 13:54:12 -0400 Francis Deslauriers wrote: > From: Masami Hiramatsu > > Prohibit kprobe-events probing on notrace function. > Since probing on the notrace function can cause recursive > event call. In most case those are just skipped, but > in some case it falls into infinite recursive call. BTW, I'm considering to add an option to allow putting kprobes on notrace function - just for debugging ftrace by kprobes. That is "developer only" option so generally it should be disabled, but for debugging the ftrace, we still need it. Or should I introduce another kprobes module for debugging it? Thank you, -- Masami Hiramatsu