Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
Message-ID: <5bacf91085ce7e253b2697333dc8ff0378fcfae9.camel@perches.com>
Subject: Re: [PATCH] checkpatch: fix false positive for REPEATED_WORD warning
From:   Joe Perches <joe@perches.com>
To:     Aditya <yashsri421@gmail.com>
Cc:     linux-kernel@vger.kernel.org, lukas.bulwahn@gmail.com,
        linux-kernel-mentees@lists.linuxfoundation.org,
        dwaipayanray1@gmail.com
Date:   Wed, 21 Oct 2020 12:26:19 -0700
In-Reply-To: <0562c42d-f9af-1141-ab77-8abb73bfd31f@gmail.com>
References: <20201021150120.29920-1-yashsri421@gmail.com>
         <f073750511750336de5f82600600ba6cb3ddbec0.camel@perches.com>
         <0562c42d-f9af-1141-ab77-8abb73bfd31f@gmail.com>
Content-Type: text/plain; charset="ISO-8859-1"
User-Agent: Evolution 3.36.4-0ubuntu1 
MIME-Version: 1.0
Content-Transfer-Encoding: 7bit
Precedence: bulk

On Thu, 2020-10-22 at 00:40 +0530, Aditya wrote:
> On 21/10/20 8:48 pm, Joe Perches wrote:
> > On Wed, 2020-10-21 at 20:31 +0530, Aditya Srivastava wrote:
> > > Presence of hexadecimal address or symbol results in false warning
> > > message by checkpatch.pl.
> > > 
> > > For example, running checkpatch on commit b8ad540dd4e4 ("mptcp: fix
> > > memory leak in mptcp_subflow_create_socket()") results in warning:
> > > 
> > > WARNING:REPEATED_WORD: Possible repeated word: 'ff'
> > >     00 00 00 00 00 00 00 00 00 2f 30 0a 81 88 ff ff  ........./0.....
> > 
> > Right.
> > 
> > > To avoid all such reports, add an additional regex check for a repeating
> > > pattern of 4 or more 2-lettered words separated by space in a line.
> > > A quick evaluation on v5.6..v5.8 showed that this fix reduces
> > > REPEATED_WORD warnings from 2797 to 1043.
> > 
> > Are many of the other 1043 false positives?
> > Any pattern to them?
> > 
> Apart from the changes suggested by Dwaipayan in
> https://lore.kernel.org/linux-kernel-mentees/20201017162732.152351-1-dwaipayanray1@gmail.com/
> 
> The 'ls -l' output seems to be another common false positive for
> REPEATED_WORD (Frequency 106 over v5.6..v5.8). For eg.
> 
> WARNING:REPEATED_WORD: Possible repeated word: 'root'
> #18:
>   drwxr-xr-x. 2 root root    0 Apr 17 10:53 .
[]
> @@ -3050,8 +3050,10 @@ sub process {
>  			}
>  		}
> 
> -		if ($rawline =~ /^\+/ || $in_commit_log) {
> +		if (($rawline =~ /^\+/ || $in_commit_log) &&
> +		$rawline !~ /\b[a-z-]+.* \d{1,3} [a-zA-Z]+ \w+ +\d+ \w{3} \d{1,2}
> \d{1,2}:\d{1,2}/) {

Perhaps a regex for permissions is good enough

	$line !~ /\b[cbdl-][rwxs-]{9,9}\b/