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Date: Thu, 29 Feb 2024 12:54:31 +0200
From: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
To: Kees Cook <keescook@chromium.org>
Cc: Jakub Kicinski <kuba@kernel.org>, 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>, 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: <ZeBiZ_aulsAqP83c@smile.fi.intel.com>
References: <20240228204919.3680786-1-andriy.shevchenko@linux.intel.com>
 <20240228204919.3680786-8-andriy.shevchenko@linux.intel.com>
 <202402281341.AC67EB6E35@keescook>
 <20240228144148.5c227487@kernel.org>
 <202402281554.C1CEEF744@keescook>
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Organization: Intel Finland Oy - BIC 0357606-4 - Westendinkatu 7, 02160 Espoo

On Wed, Feb 28, 2024 at 04:01:49PM -0800, Kees Cook wrote:
> On Wed, Feb 28, 2024 at 02:41:48PM -0800, Jakub Kicinski wrote:
> > On Wed, 28 Feb 2024 13:46:10 -0800 Kees Cook wrote:

..

> But I still like the idea -- Gustavo has been solving these cases with
> having two structs, e.g.:
> 
> struct net_device {
> 	...unchanged...
> };
> 
> struct net_device_alloc {
> 	struct net_device	dev;
> 	u32			priv_size;
> 	u8			priv_data[] __counted_by(priv_size) __aligned(NETDEV_ALIGN);
> };
> 
> And internals can use struct net_device_alloc...

I just realized that I made same approach in 

f6d7f050e258 ("spi: Don't use flexible array in struct spi_message definition")
75e308ffc4f0 ("spi: Use struct_size() helper")


-- 
With Best Regards,
Andy Shevchenko