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=-8.2 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, 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 22F0EC282C0 for ; Wed, 23 Jan 2019 08:10:07 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E617721019 for ; Wed, 23 Jan 2019 08:10:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1548231007; bh=7J0pDHtZRLVxwU1gvRx1ZGnqrK3uix9v79Dk4CrIbCU=; h=Date:From:To:Cc:Subject:In-Reply-To:References:List-ID:From; b=y7/zegs3rtjGwrcpd208KVIHs/m5qnVTWpePrFARTS9mn6lUPEE9kVkmi0zzkUpmz kPtm90pu35qyg/Qr82J/d0S1yjySGjDKgm0c5brW+2fYPugqy0ze8Bja49TsJYw81u fwRyTVimBdJOYkgjPF6RLiL53RdCq13yjb/tAzfI= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726611AbfAWIKF (ORCPT ); Wed, 23 Jan 2019 03:10:05 -0500 Received: from mail.kernel.org ([198.145.29.99]:59200 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726000AbfAWIKE (ORCPT ); Wed, 23 Jan 2019 03:10:04 -0500 Received: from devnote (p105099-mobac01.tokyo.ocn.ne.jp [153.233.96.99]) (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 0BD0321019; Wed, 23 Jan 2019 08:10:02 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1548231004; bh=7J0pDHtZRLVxwU1gvRx1ZGnqrK3uix9v79Dk4CrIbCU=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=iCFitbs62RFTfGnMmtiQwZA0pSHx5zp0uJS6JQUuR+xhWXruqWchJDikk2/i/TzJy 2xTQ8ekwWmIgGLPNzBo9KfaVxQPMeixFM8E/DhHM4zqPwcgBlaqWyIB2AWvyZgKPBM xTSowvNaAmY4QQYm1hFy3UwUx8S9o+/dJE0mrJiU= Date: Wed, 23 Jan 2019 17:10:00 +0900 From: Masami Hiramatsu To: Greg Kroah-Hartman Cc: linux-kernel@vger.kernel.org, "Naveen N. Rao" , Anil S Keshavamurthy , "David S. Miller" Subject: Re: [PATCH] kprobes: no need to check return value of debugfs_create functions Message-Id: <20190123171000.b1cbc9e1b52251bdd78b2338@kernel.org> In-Reply-To: <20190123065422.GA27466@kroah.com> References: <20190122152151.16139-47-gregkh@linuxfoundation.org> <20190123111516.d5fd81cb315810235205fbeb@kernel.org> <20190123065422.GA27466@kroah.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 Wed, 23 Jan 2019 07:54:22 +0100 Greg Kroah-Hartman wrote: > On Wed, Jan 23, 2019 at 11:15:16AM +0900, Masami Hiramatsu wrote: > > On Tue, 22 Jan 2019 16:21:46 +0100 > > Greg Kroah-Hartman wrote: > > > > > When calling debugfs functions, there is no need to ever check the > > > return value. The function can work or not, but the code logic should > > > never do something different based on this. > > > > > > Cc: "Naveen N. Rao" > > > Cc: Anil S Keshavamurthy > > > Cc: "David S. Miller" > > > Cc: Masami Hiramatsu > > > Signed-off-by: Greg Kroah-Hartman > > > --- > > > kernel/kprobes.c | 25 ++++++------------------- > > > 1 file changed, 6 insertions(+), 19 deletions(-) > > > > > > diff --git a/kernel/kprobes.c b/kernel/kprobes.c > > > index f4ddfdd2d07e..7287e7de2350 100644 > > > --- a/kernel/kprobes.c > > > +++ b/kernel/kprobes.c > > > @@ -2566,33 +2566,20 @@ static const struct file_operations fops_kp = { > > > > > > static int __init debugfs_kprobe_init(void) > > > { > > > - struct dentry *dir, *file; > > > + struct dentry *dir; > > > unsigned int value = 1; > > > > > > dir = debugfs_create_dir("kprobes", NULL); > > > - if (!dir) > > > - return -ENOMEM; > > > > Here, I think IS_ERR(dir) is OK for debugfs_create_file(), > > but dir == NULL has different meaning. I think we'd better > > keep this check. (I see, -ENOMEM will be no good...) > > dir == NULL means the system is out of memory. Which I'll change and > just make it return an error, so it is fine to ignore this value. Got it! Thanks! Acked-by: Masami Hiramatsu > > thanks, > > greg k-h -- Masami Hiramatsu