Received-SPF: pass (google.com: domain of linux-kernel+bounces-85746-linux.lists.archive=gmail.com@vger.kernel.org designates 2604:1380:40f1:3f00::1 as permitted sender) client-ip=2604:1380:40f1:3f00::1;
Date: Wed, 28 Feb 2024 23:53:17 +0200
From: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
To: Kees Cook <keescook@chromium.org>
Cc: Vinod Koul <vkoul@kernel.org>, Linus Walleij <linus.walleij@linaro.org>,
	Jonathan Cameron <Jonathan.Cameron@huawei.com>,
	Mark Brown <broonie@kernel.org>,
	linux-arm-kernel@lists.infradead.org, dmaengine@vger.kernel.org,
	linux-kernel@vger.kernel.org, linux-iio@vger.kernel.org,
	linux-spi@vger.kernel.org, netdev@vger.kernel.org,
	linux-hardening@vger.kernel.org,
	Jonathan Cameron <jic23@kernel.org>,
	Lars-Peter Clausen <lars@metafoo.de>,
	"David S. Miller" <davem@davemloft.net>,
	Eric Dumazet <edumazet@google.com>,
	Jakub Kicinski <kuba@kernel.org>, Paolo Abeni <pabeni@redhat.com>,
	"Gustavo A. R. Silva" <gustavoars@kernel.org>
Subject: Re: [PATCH v4 7/8] net-device: Use new helpers from overflow.h in
 netdevice APIs
Message-ID: <Zd-rTRidOqOd4Gr7@smile.fi.intel.com>
References: <20240228204919.3680786-1-andriy.shevchenko@linux.intel.com>
 <20240228204919.3680786-8-andriy.shevchenko@linux.intel.com>
 <202402281341.AC67EB6E35@keescook>
Precedence: bulk
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <202402281341.AC67EB6E35@keescook>
Organization: Intel Finland Oy - BIC 0357606-4 - Westendinkatu 7, 02160 Espoo

On Wed, Feb 28, 2024 at 01:46:10PM -0800, Kees Cook wrote:
> On Wed, Feb 28, 2024 at 10:41:37PM +0200, Andy Shevchenko wrote:

..

> >  static inline void *netdev_priv(const struct net_device *dev)
> >  {
> > -	return (char *)dev + ALIGN(sizeof(struct net_device), NETDEV_ALIGN);
> > +	return struct_data_pointer(dev, NETDEV_ALIGN);
> >  }
> 
> I really don't like hiding these trailing allocations from the compiler.
> Why can't something like this be done (totally untested):

Below is interesting idea, now at least I started understanding your previous
comments.

-- 
With Best Regards,
Andy Shevchenko