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;
Date:   Wed, 8 Jul 2020 08:53:30 +0200
From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     Saheed Olayemi Bolarinwa <refactormyself@gmail.com>
Cc:     helgaas@kernel.org, Arnd Bergmann <arnd@arndb.de>,
        bjorn@helgaas.com, skhan@linuxfoundation.org,
        linux-kernel-mentees@lists.linuxfoundation.org,
        linux-kernel@vger.kernel.org
Subject: Re: [PATCH 2/13] misc: rtsx: Check the return value of
 pcie_capability_read_*()
Message-ID: <20200708065330.GA348669@kroah.com>
References: <20200707220324.8425-1-refactormyself@gmail.com>
 <20200707220324.8425-3-refactormyself@gmail.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <20200707220324.8425-3-refactormyself@gmail.com>
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

On Wed, Jul 08, 2020 at 12:03:13AM +0200, Saheed Olayemi Bolarinwa wrote:
> From: Bolarinwa Olayemi Saheed <refactormyself@gmail.com>
> 
> On failure pcie_capability_read_dword() sets it's last parameter, val
> to 0. In which case (val & PCI_EXP_DEVCTL2_LTR_EN) evaluates to 0.
> However, with Patch 13/13, it is possible that val is set to ~0 on
> failure. This would introduce a bug because (x & x) == (~0 & x).
> 
> This bug can be avoided without changing the function's behaviour if the
> return value of pcie_capability_read_word is checked to confirm success.
> 
> Check the return value of pcie_capability_read_word() to ensure success.
> 
> Suggested-by: Bjorn Helgaas <bjorn@helgaas.com>
> Signed-off-by: Bolarinwa Olayemi Saheed <refactormyself@gmail.com>

Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>