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=-16.2 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,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 C29A4C433DB for ; Wed, 20 Jan 2021 03:26:41 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 70AD8207CF for ; Wed, 20 Jan 2021 03:26:41 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728039AbhATD0i (ORCPT ); Tue, 19 Jan 2021 22:26:38 -0500 Received: from mail.kernel.org ([198.145.29.99]:40612 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727630AbhATDZF (ORCPT ); Tue, 19 Jan 2021 22:25:05 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id E579E207CF; Wed, 20 Jan 2021 03:24:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1611113058; bh=4l5m100OkQzuADlrQgWF3YznK8+tUXDL2rs5lRR33RM=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=sCu1cBwZFbp9XRAA0kjheMbhV1fxIn37dIUhI0IhxQq/+FA7zjjNSOkNaGZaDlRJP EWqwURZhp4cgMKcATlM8z8OlTnD1E7wCwhNahi51wz0LbE/L+VxNkeGWfdR+cNFFn8 Dh9PFV09n081710pOQjVXUE/icrA/puLDa6PsW+SUzgRfcIXMj7lGxOxIpl4U8Fkb9 AGM7/KSkKemEnFNibEGVNi1DC/AXrMLiiPXkdXZ1MwN3w33HNkd88jIktseHMJw254 QgtihCu1100LUof13L8tFTlrnDb82NsqaFJ5/hfeVMS+ZrRYaB63Fm7zMWq4G6Shjh ACU0vftfY1bog== Date: Wed, 20 Jan 2021 12:24:15 +0900 From: Masami Hiramatsu To: Steven Rostedt Cc: Jianlin Lv , mingo@redhat.com, linux-kernel@vger.kernel.org Subject: Re: [PATCH] tracing: precise log info for kretprobe addr err Message-Id: <20210120122415.76fa3539ce031bfb90e1c862@kernel.org> In-Reply-To: <20210119104106.2213a49c@gandalf.local.home> References: <20210119151014.3822465-1-Jianlin.Lv@arm.com> <20210119104106.2213a49c@gandalf.local.home> X-Mailer: Sylpheed 3.7.0 (GTK+ 2.24.32; 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 Hi, On Tue, 19 Jan 2021 10:41:06 -0500 Steven Rostedt wrote: > Masami, > > Looks fine to me. What do you think? Agreed. Since register_kretprobe() checks the address by kprobe_on_func_entry(), if it is not passed, it should always fail to register at last. Acked-by: Masami Hiramatsu Thank you! > > -- Steve > > > On Tue, 19 Jan 2021 23:10:14 +0800 > Jianlin Lv wrote: > > > When trying to create kretprobe with the wrong function symbol in tracefs; > > The error is triggered in the register_trace_kprobe() and recorded as > > FAIL_REG_PROBE issue, > > > > Example: > > $ cd /sys/kernel/debug/tracing > > $ echo 'r:myprobe ERROR_SYMBOL_XXX ret=%x0' >> kprobe_events > > bash: echo: write error: Invalid argument > > $ cat error_log > > [142797.347877] trace_kprobe: error: Failed to register probe event > > Command: r:myprobe ERROR_SYMBOL_XXX ret=%x0 > > ^ > > > > This error can be detected in the parameter parsing stage, the effect of > > applying this patch is as follows: > > > > $ echo 'r:myprobe ERROR_SYMBOL_XXX ret=%x0' >> kprobe_events > > bash: echo: write error: Invalid argument > > $ cat error_log > > [415.89]trace_kprobe: error: Retprobe address must be an function entry > > Command: r:myprobe ERROR_SYMBOL_XXX ret=%x0 > > ^ > > > > Signed-off-by: Jianlin Lv > > --- > > kernel/trace/trace_kprobe.c | 2 +- > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c > > index e6fba1798771..3dfd1b6711a3 100644 > > --- a/kernel/trace/trace_kprobe.c > > +++ b/kernel/trace/trace_kprobe.c > > @@ -830,7 +830,7 @@ static int trace_kprobe_create(int argc, const char *argv[]) > > flags |= TPARG_FL_RETURN; > > if (kprobe_on_func_entry(NULL, symbol, offset)) > > flags |= TPARG_FL_FENTRY; > > - if (offset && is_return && !(flags & TPARG_FL_FENTRY)) { > > + if (is_return && !(flags & TPARG_FL_FENTRY)) { > > trace_probe_log_err(0, BAD_RETPROBE); > > goto parse_error; > > } > -- Masami Hiramatsu