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Date:   Fri, 8 Feb 2019 07:51:08 -0800
From:   Jakub Kicinski <jakub.kicinski@netronome.com>
To:     "Gustavo A. R. Silva" <gustavo@embeddedor.com>
Cc:     "David S. Miller" <davem@davemloft.net>, oss-drivers@netronome.com,
        netdev@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH net-next] nfp: flower: cmsg: use struct_size() helper
Message-ID: <20190208075108.68763aca@cakuba.netronome.com>
In-Reply-To: <20190208034725.GA12043@embeddedor>
References: <20190208034725.GA12043@embeddedor>
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On Thu, 7 Feb 2019 21:47:25 -0600, Gustavo A. R. Silva wrote:
> One of the more common cases of allocation size calculations is finding
> the size of a structure that has a zero-sized array at the end, along
> with memory for some number of elements for that array. For example:
> 
> struct foo {
>     int stuff;
>     void *entry[];
> };
> 
> size = sizeof(struct foo) + count * sizeof(void *);
> instance = alloc(size, GFP_KERNEL);
> 
> Instead of leaving these open-coded and prone to type mistakes, we can
> now use the new struct_size() helper:
> 
> instance = alloc(struct_size(instance, entry, count), GFP_KERNEL);
> 
> Notice that, in this case, variable size is not necessary, hence
> it is removed.
> 
> This code was detected with the help of Coccinelle.
> 
> Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>

Acked-by: Jakub Kicinski <jakub.kicinski@netronome.com>