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=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,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 943F6C67790 for ; Fri, 27 Jul 2018 13:38:47 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 266A720873 for ; Fri, 27 Jul 2018 13:38:47 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 266A720873 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=goodmis.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 S1731002AbeG0PAn (ORCPT ); Fri, 27 Jul 2018 11:00:43 -0400 Received: from mail.kernel.org ([198.145.29.99]:48852 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730395AbeG0PAm (ORCPT ); Fri, 27 Jul 2018 11:00:42 -0400 Received: from gandalf.local.home (cpe-66-24-56-78.stny.res.rr.com [66.24.56.78]) (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 E432320873; Fri, 27 Jul 2018 13:38:43 +0000 (UTC) Date: Fri, 27 Jul 2018 09:38:41 -0400 From: Steven Rostedt To: Masami Hiramatsu Cc: Josh Poimboeuf , LKML , Artem Savkov Subject: [PATCH v2] tracing/kprobes: Simplify the logic of enable_trace_kprobe() Message-ID: <20180727093841.73f27a7b@gandalf.local.home> In-Reply-To: <20180727215202.0af90e09709f7699e033ef54@kernel.org> References: <20180726121152.4dd54330@gandalf.local.home> <20180726164352.tctldcryo4fs3nap@treble> <20180727215202.0af90e09709f7699e033ef54@kernel.org> X-Mailer: Claws Mail 3.16.0 (GTK+ 2.24.32; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: "Steven Rostedt (VMware)" The function enable_trace_kprobe() performs slightly differently if the file parameter is passed in as NULL on non-NULL. Instead of checking file twice, move the code between the two tests into a static inline helper function to make the code easier to follow. Link: http://lkml.kernel.org/r/20180725224728.7b1d5db2@vmware.local.home Link: http://lkml.kernel.org/r/20180726121152.4dd54330@gandalf.local.home Reviewed-by: Josh Poimboeuf Acked-by: Masami Hiramatsu Signed-off-by: Steven Rostedt (VMware) --- kernel/trace/trace_kprobe.c | 42 ++++++++++++++++++++++++------------------ 1 file changed, 24 insertions(+), 18 deletions(-) diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c index 6b71860f3998..0534eb8b7640 100644 --- a/kernel/trace/trace_kprobe.c +++ b/kernel/trace/trace_kprobe.c @@ -393,6 +393,20 @@ static struct trace_kprobe *find_trace_kprobe(const char *event, return NULL; } +static inline int __enable_trace_kprobe(struct trace_kprobe *tk) +{ + int ret = 0; + + if (trace_probe_is_registered(&tk->tp) && !trace_kprobe_has_gone(tk)) { + if (trace_kprobe_is_return(tk)) + ret = enable_kretprobe(&tk->rp); + else + ret = enable_kprobe(&tk->rp.kp); + } + + return ret; +} + /* * Enable trace_probe * if the file is NULL, enable "perf" handler, or enable "trace" handler. @@ -400,7 +414,7 @@ static struct trace_kprobe *find_trace_kprobe(const char *event, static int enable_trace_kprobe(struct trace_kprobe *tk, struct trace_event_file *file) { - struct event_file_link *link = NULL; + struct event_file_link *link; int ret = 0; if (file) { @@ -414,26 +428,18 @@ enable_trace_kprobe(struct trace_kprobe *tk, struct trace_event_file *file) list_add_tail_rcu(&link->list, &tk->tp.files); tk->tp.flags |= TP_FLAG_TRACE; - } else - tk->tp.flags |= TP_FLAG_PROFILE; - - if (trace_probe_is_registered(&tk->tp) && !trace_kprobe_has_gone(tk)) { - if (trace_kprobe_is_return(tk)) - ret = enable_kretprobe(&tk->rp); - else - ret = enable_kprobe(&tk->rp.kp); - } - - if (ret) { - if (file) { - /* Notice the if is true on not WARN() */ - if (!WARN_ON_ONCE(!link)) - list_del_rcu(&link->list); + ret = __enable_trace_kprobe(tk); + if (ret) { + list_del_rcu(&link->list); kfree(link); tk->tp.flags &= ~TP_FLAG_TRACE; - } else { - tk->tp.flags &= ~TP_FLAG_PROFILE; } + + } else { + tk->tp.flags |= TP_FLAG_PROFILE; + ret = __enable_trace_kprobe(tk); + if (ret) + tk->tp.flags &= ~TP_FLAG_PROFILE; } out: return ret; -- 2.13.6