Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751500AbeAECOd (ORCPT + 1 other); Thu, 4 Jan 2018 21:14:33 -0500 Received: from aserp2120.oracle.com ([141.146.126.78]:57694 "EHLO aserp2120.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751166AbeAECOc (ORCPT ); Thu, 4 Jan 2018 21:14:32 -0500 Subject: Re: [PATCH 1/2] Move kfree_call_rcu() to slab_common.c To: Matthew Wilcox , "Paul E. McKenney" Cc: Joe Perches , Boqun Feng , linux-kernel@vger.kernel.org, brouer@redhat.com, linux-mm@kvack.org 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 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.5.0 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 X-Proofpoint-Virus-Version: vendor=nai engine=5900 definitions=8764 signatures=668651 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 suspectscore=0 malwarescore=0 phishscore=0 bulkscore=0 spamscore=0 mlxscore=0 mlxlogscore=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1711220000 definitions=main-1801050024 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Return-Path: 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