From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-io0-f197.google.com (mail-io0-f197.google.com [209.85.223.197]) by kanga.kvack.org (Postfix) with ESMTP id CF7CF6B0328 for ; Thu, 4 Jan 2018 21:14:28 -0500 (EST) Received: by mail-io0-f197.google.com with SMTP id s24so3421964ioa.9 for ; Thu, 04 Jan 2018 18:14:28 -0800 (PST) Received: from aserp2120.oracle.com (aserp2120.oracle.com. [141.146.126.78]) by mx.google.com with ESMTPS id t185si3510767iod.43.2018.01.04.18.14.27 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 04 Jan 2018 18:14:27 -0800 (PST) Subject: Re: [PATCH 1/2] Move kfree_call_rcu() to slab_common.c References: <1514923898-2495-1-git-send-email-rao.shoaib@oracle.com> <20180102222341.GB20405@bombadil.infradead.org> <3be609d4-800e-a89e-f885-7e0f5d288862@oracle.com> <20180104013807.GA31392@tardis> <64ca3929-4044-9393-a6ca-70c0a2589a35@oracle.com> <20180104214658.GA20740@bombadil.infradead.org> <3e4ea0b9-686f-7e36-d80c-8577401517e2@oracle.com> <20180104231307.GA794@bombadil.infradead.org> <20180104234732.GM9671@linux.vnet.ibm.com> <20180105000707.GA22237@bombadil.infradead.org> From: Rao Shoaib Message-ID: Date: Thu, 4 Jan 2018 18:14:08 -0800 MIME-Version: 1.0 In-Reply-To: <20180105000707.GA22237@bombadil.infradead.org> Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Content-Language: en-US Sender: owner-linux-mm@kvack.org List-ID: To: Matthew Wilcox , "Paul E. McKenney" Cc: Joe Perches , Boqun Feng , linux-kernel@vger.kernel.org, brouer@redhat.com, linux-mm@kvack.org On 01/04/2018 04:07 PM, Matthew Wilcox wrote: > On Thu, Jan 04, 2018 at 03:47:32PM -0800, Paul E. McKenney wrote: >> I was under the impression that typeof did not actually evaluate its >> argument, but rather only returned its type. And there are a few macros >> with this pattern in mainline. >> >> Or am I confused about what typeof does? > I think checkpatch is confused by the '*' in the typeof argument: Yup. > > $ git diff |./scripts/checkpatch.pl --strict > CHECK: Macro argument reuse 'ptr' - possible side-effects? > #29: FILE: include/linux/rcupdate.h:896: > +#define kfree_rcu(ptr, rcu_head) \ > + __kfree_rcu(&((ptr)->rcu_head), offsetof(typeof(*(ptr)), rcu_head)) > > If one removes the '*', the warning goes away. > > I'm no perlista, but Joe, would this regexp modification make sense? > > +++ b/scripts/checkpatch.pl > @@ -4957,7 +4957,7 @@ sub process { > next if ($arg =~ /\.\.\./); > next if ($arg =~ /^type$/i); > my $tmp_stmt = $define_stmt; > - $tmp_stmt =~ s/\b(typeof|__typeof__|__builtin\w+|typecheck\s*\(\s*$Type\s*,|\#+)\s*\(*\s*$arg\s*\)*\b//g; > + $tmp_stmt =~ s/\b(typeof|__typeof__|__builtin\w+|typecheck\s*\(\s*$Type\s*,|\#+)\s*\(*\**\(*\s*$arg\s*\)*\b//g; > $tmp_stmt =~ s/\#+\s*$arg\b//g; > $tmp_stmt =~ s/\b$arg\s*\#\#//g; > my $use_cnt = $tmp_stmt =~ s/\b$arg\b//g; > Thanks a lot for digging into this. I had to try several variations for the warning to go away and don't remember the reason for each change. I am not perl literate and the regular expression sacred me ;-). Shoaib -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org