From mboxrd@z Thu Jan  1 00:00:00 1970
From: Jason Gunthorpe <jgg@ziepe.ca>
Subject: Re: [PATCH][next] treewide: uapi: Replace zero-length arrays with
 flexible-array members
Date: Tue, 28 Jun 2022 15:44:04 -0300
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To: Kees Cook <keescook@chromium.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>, "Gustavo A. R. Silva" <gustavoars@kernel.org>, linux-kernel@vger.kernel.org, x86@kernel.org, dm-devel@redhat.com, linux-m68k@lists.linux-m68k.org, linux-mips@vger.kernel.org, linux-s390@vger.kernel.org, kvm@vger.kernel.org, intel-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org, netdev@vger.kernel.org, bpf@vger.kernel.org, linux-btrfs@vger.kernel.org, linux-can@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux1394-devel@lists.sourceforge.net, io-uring@vger.kernel.org, lvs-devel@vger.kernel.org, linux-mtd@lists.infradead.org, kasan-dev@googlegroups.com, linux-mmc@vger.kernel.org, nvdimm@lists.linux.dev, netfilter-devel@vger.kernel.org, coreteam@netfilter.org, linux-perf-users@vger.kernel.org, linux-raid@vger.kernel.org, l

On Tue, Jun 28, 2022 at 10:54:58AM -0700, Kees Cook wrote:

 
> which must also be assuming it's a header. So probably better to just
> drop the driver_data field? I don't see anything using it (that I can
> find) besides as a sanity-check that the field exists and is at the end
> of the struct.

The field is guaranteeing alignment of the following structure. IIRC
there are a few cases that we don't have a u64 already to force this.

Jason