Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
Date:   Tue, 1 Feb 2022 16:30:23 +0000
From:   Matthew Wilcox <willy@infradead.org>
To:     =?iso-8859-1?Q?Ma=EDra?= Canal <maira.canal@usp.br>
Cc:     gregkh@linuxfoundation.org, tj@kernel.org, viro@zeniv.linux.org.uk,
        nathan@kernel.org, ndesaulniers@google.com,
        linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org,
        llvm@lists.linux.dev
Subject: Re: [PATCH v3] seq_file: fix NULL pointer arithmetic warning
Message-ID: <YflgH+uaoMJTlUoK@casper.infradead.org>
References: <Yfgo8p6Vk+h4+YHY@fedora>
MIME-Version: 1.0
Content-Type: text/plain; charset=iso-8859-1
Content-Disposition: inline
Content-Transfer-Encoding: 8bit
In-Reply-To: <Yfgo8p6Vk+h4+YHY@fedora>
Precedence: bulk

On Mon, Jan 31, 2022 at 03:22:42PM -0300, Ma?ra Canal wrote:
> Implement conditional logic in order to replace NULL pointer arithmetic.
> 
> The use of NULL pointer arithmetic was pointed out by clang with the
> following warning:
> 
> fs/kernfs/file.c:128:15: warning: performing pointer arithmetic on a
> null pointer has undefined behavior [-Wnull-pointer-arithmetic]
>                 return NULL + !*ppos;
>                        ~~~~ ^
> fs/seq_file.c:559:14: warning: performing pointer arithmetic on a
> null pointer has undefined behavior [-Wnull-pointer-arithmetic]
>         return NULL + (*pos == 0);
> 
> Signed-off-by: Ma?ra Canal <maira.canal@usp.br>

Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>