Re: [PATCH] netdev: Use flexible array for trailing private bytes

From: Eric Dumazet <edumazet@google.com>
To: Jakub Kicinski <kuba@kernel.org>
Cc: Kees Cook <keescook@chromium.org>,
	"David S. Miller" <davem@davemloft.net>,
	 Paolo Abeni <pabeni@redhat.com>,
	Andy Shevchenko <andriy.shevchenko@linux.intel.com>,
	 "Gustavo A. R. Silva" <gustavoars@kernel.org>,
	netdev@vger.kernel.org,  linux-hardening@vger.kernel.org,
	Simon Horman <horms@kernel.org>,  Jiri Pirko <jiri@resnulli.us>,
	Daniel Borkmann <daniel@iogearbox.net>,
	Coco Li <lixiaoyan@google.com>,
	 Amritha Nambiar <amritha.nambiar@intel.com>,
	linux-kernel@vger.kernel.org
Subject: Re: [PATCH] netdev: Use flexible array for trailing private bytes
Date: Fri, 1 Mar 2024 09:03:55 +0100	[thread overview]
Message-ID: <CANn89iKeJGvhY0K=kLhhR39NVbaizP2UBk0Vk0r_XCe2XMBZHg@mail.gmail.com> (raw)
In-Reply-To: <20240229225910.79e224cf@kernel.org>

On Fri, Mar 1, 2024 at 7:59 AM Jakub Kicinski <kuba@kernel.org> wrote:
>
> On Thu, 29 Feb 2024 13:30:22 -0800 Kees Cook wrote:

> > diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
> > index 118c40258d07..b476809d0bae 100644
> > --- a/include/linux/netdevice.h
> > +++ b/include/linux/netdevice.h
> > @@ -1815,6 +1815,8 @@ enum netdev_stat_type {
> >       NETDEV_PCPU_STAT_DSTATS, /* struct pcpu_dstats */
> >  };
> >
> > +#define      NETDEV_ALIGN            32
>
> Unless someone knows what this is for it should go.
> Align priv to cacheline size.

+2

#define NETDEV_ALIGN    L1_CACHE_BYTES

or a general replacement of NETDEV_ALIGN....