On 03/25/2014 05:17 PM, David Miller wrote:
> From: Daniel Borkmann <[email protected]>
> Date: Tue, 25 Mar 2014 13:10:56 +0100
>
>> - Conditional jt/jf targets replaced with jt/fall-through,
>> and forward/backward jumps now possible as well
>
> Ummm... does anyone even remember why backwards jumps were not allowed
> in the original BPF?
>
> It's to guarentee forward progress in the filter.
>
> Allowing branching backward would allow endless loops.
>
> Please remove this feature.
>
If you allow loops, it greatly increases the expressibility of the
language, but we would really need another control to limit CPU usage.
-hpa
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