From mboxrd@z Thu Jan 1 00:00:00 1970 From: Kees Cook Subject: Re: [PATCH v17 03/15] arm64: Introduce prctl() options to control the tagged user addresses ABI Date: Thu, 13 Jun 2019 22:13:54 -0700 Message-ID: <201906132209.FC65A3C771@keescook> References: <20190613110235.GW28398@e103592.cambridge.arm.com> <20190613152632.GT28951@C02TF0J2HF1T.local> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <20190613152632.GT28951@C02TF0J2HF1T.local> Sender: linux-kernel-owner@vger.kernel.org To: Catalin Marinas Cc: Dave Martin , Andrey Konovalov , linux-arm-kernel@lists.infradead.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, amd-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org, linux-rdma@vger.kernel.org, linux-media@vger.kernel.org, kvm@vger.kernel.org, linux-kselftest@vger.kernel.org, Mark Rutland , Szabolcs Nagy , Will Deacon , Kostya Serebryany , Khalid Aziz , Felix Kuehling , Vincenzo Frascino , Jacob Bramley , Leon Romanovsky , Christoph Hellwig , Jason Gunthorpe List-Id: linux-rdma@vger.kernel.org On Thu, Jun 13, 2019 at 04:26:32PM +0100, Catalin Marinas wrote: > On Thu, Jun 13, 2019 at 12:02:35PM +0100, Dave P Martin wrote: > > On Wed, Jun 12, 2019 at 01:43:20PM +0200, Andrey Konovalov wrote: > > > +static int zero; > > > +static int one = 1; > > > > !!! > > > > And these can't even be const without a cast. Yuk. > > > > (Not your fault though, but it would be nice to have a proc_dobool() to > > avoid this.) > > I had the same reaction. Maybe for another patch sanitising this pattern > across the kernel. That's actually already happening (via -mm tree last I looked). tl;dr: it ends up using a cast hidden in a macro. It's in linux-next already along with a checkpatch.pl addition to yell about doing what's being done here. ;) https://lore.kernel.org/lkml/20190430180111.10688-1-mcroce@redhat.com/#r -- Kees Cook