From: Daniel Borkmann <daniel@iogearbox.net>
To: David Laight <David.Laight@ACULAB.COM>,
'Florian Westphal' <fw@strlen.de>,
"netdev@vger.kernel.org" <netdev@vger.kernel.org>
Subject: Re: [PATCH v2] net: bridge: add compile-time assert for cb struct size
Date: Tue, 03 Mar 2015 15:28:47 +0100 [thread overview]
Message-ID: <54F5C51F.5020906@iogearbox.net> (raw)
In-Reply-To: <063D6719AE5E284EB5DD2968C1650D6D1CAF3BB7@AcuExch.aculab.com>
On 03/03/2015 02:50 PM, David Laight wrote:
...
>> + BUILD_BUG_ON(sizeof(struct br_input_skb_cb) > FIELD_SIZEOF(struct sk_buff, cb));
>> +
>
> What about using something based on:
> #define GET_CB(skb, type) ((type *)((skb)->cb + (sizeof (char[(sizeof (type) <= sizeof (skb->cb)) ? 1 : -1] - 1)))
> to access skb->sb?
That would require to change all skb->cb[] call-sites everywhere.
Besides that, this macro is also buggy, my totally untrained lisp-eye tells
me that you got your brackets wrong.
Cheers,
Daniel
next prev parent reply other threads:[~2015-03-03 14:28 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-03-03 12:53 [PATCH v2] net: bridge: add compile-time assert for cb struct size Florian Westphal
2015-03-03 13:50 ` David Laight
2015-03-03 14:07 ` Eric Dumazet
2015-03-03 14:15 ` David Laight
2015-03-03 14:33 ` Eric Dumazet
2015-03-03 14:28 ` Daniel Borkmann [this message]
2015-03-03 14:44 ` David Laight
2015-03-03 14:51 ` Eyal Birger
2015-03-03 19:07 ` David Miller
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