Re: [PATCH v4 1/4] x86/ibt: factor out cfi and fineibt offset

H. Peter Anvin
2025-03-04T14:55:04Z

On March 4, 2025 1:42:20 AM PST, Peter Zijlstra <peterz@infradead.org> wrote:
>On Tue, Mar 04, 2025 at 03:47:45PM +0800, Menglong Dong wrote:
>> We don't have to select FUNCTION_ALIGNMENT_32B, so the
>> worst case is to increase ~2.2%.
>>
>> What do you think?
>
>Well, since I don't understand what you need this for at all, I'm firmly
>on the side of not doing this.
>
>What actual problem is being solved with this meta data nonsense? Why is
>it worth blowing up our I$ footprint over.
>
>Also note, that if you're going to be explaining this, start from
>scratch, as I have absolutely 0 clues about BPF and such.

I would appreciate such information as well. The idea seems dubious on the surface.