Re: [PATCH net-next v2 8/9] net: filter: rework/optimize internal BPF interpreter's instruction set
From: H. Peter Anvin <hidden>
Date: 2014-03-26 00:24:30
Also in:
lkml
From: H. Peter Anvin <hidden>
Date: 2014-03-26 00:24:30
Also in:
lkml
On 03/25/2014 05:17 PM, David Miller wrote:
From: Daniel Borkmann <redacted> Date: Tue, 25 Mar 2014 13:10:56 +0100quoted
- Conditional jt/jf targets replaced with jt/fall-through, and forward/backward jumps now possible as wellUmmm... 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