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Date:   Thu, 19 Aug 2021 10:09:02 +0100
From:   Christoph Hellwig <hch@infradead.org>
To:     Kees Cook <keescook@chromium.org>
Cc:     linux-kernel@vger.kernel.org,
        Andrew Morton <akpm@linux-foundation.org>,
        Miguel Ojeda <ojeda@kernel.org>,
        Nathan Chancellor <nathan@kernel.org>,
        Nick Desaulniers <ndesaulniers@google.com>,
        Daniel Micay <danielmicay@gmail.com>,
        Christoph Lameter <cl@linux.com>,
        Pekka Enberg <penberg@kernel.org>,
        David Rientjes <rientjes@google.com>,
        Joonsoo Kim <iamjoonsoo.kim@lge.com>,
        Vlastimil Babka <vbabka@suse.cz>,
        Dennis Zhou <dennis@kernel.org>, Tejun Heo <tj@kernel.org>,
        Masahiro Yamada <masahiroy@kernel.org>,
        Michal Marek <michal.lkml@markovi.net>,
        clang-built-linux@googlegroups.com, linux-mm@kvack.org,
        linux-kbuild@vger.kernel.org, linux-hardening@vger.kernel.org
Subject: Re: [PATCH 0/5] Add __alloc_size() for better bounds checking
Message-ID: <YR4frlpfJQonPuKp@infradead.org>
References: <20210818050841.2226600-1-keescook@chromium.org>
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On Tue, Aug 17, 2021 at 10:08:36PM -0700, Kees Cook wrote:
> Hi,
> 
> GCC and Clang both use the "alloc_size" attribute to assist with bounds
> checking around the use of allocation functions. Add the attribute,
> adjust the Makefile to silence needless warnings, and add the hints to
> the allocators where possible. These changes have been in use for a
> while now in GrapheneOS.

Can you explain how this attribute helps?  Should we flow it through
other allocating functions?