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Date:   Mon, 2 Oct 2023 00:36:28 -0700
From:   Kees Cook <keescook@chromium.org>
To:     Julia Lawall <julia.lawall@inria.fr>
Cc:     Kees Cook <kees@kernel.org>,
        Christophe JAILLET <christophe.jaillet@wanadoo.fr>,
        Ian Abbott <abbotti@mev.co.uk>,
        H Hartley Sweeten <hsweeten@visionengravers.com>,
        "Gustavo A. R. Silva" <gustavoars@kernel.org>,
        Nathan Chancellor <nathan@kernel.org>,
        Nick Desaulniers <ndesaulniers@google.com>,
        Tom Rix <trix@redhat.com>, linux-kernel@vger.kernel.org,
        kernel-janitors@vger.kernel.org, linux-hardening@vger.kernel.org,
        llvm@lists.linux.dev
Subject: Re: [PATCH] comedi: Annotate struct comedi_lrange with __counted_by
Message-ID: <202310020036.864B735D60@keescook>
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On Mon, Oct 02, 2023 at 07:38:42AM +0200, Julia Lawall wrote:
> The sizeof with an expression argument is treated differently than the
> sizeof with a type argument.  So you need to write:
> 
> @allocated@
> identifier STRUCT, ARRAY;
> expression COUNT;
> struct STRUCT *PTR;
> identifier ALLOC;
> type ELEMENT_TYPE;
> @@
> 
>         PTR = ALLOC(..., \(sizeof(*PTR)\|sizeof(struct STRUCT)\) +
>                          COUNT * \(sizeof(*PTR->ARRAY)\|sizeof(PTR->ARRAY[0])\|sizeof(ELEMENT_TYPE)\), ...);

Ah! Thank you thank you! Yes, this works great now. :)

-- 
Kees Cook