Messages in this thread | | | Date | Thu, 18 Sep 2014 19:28:04 +0200 | From | Daniel Borkmann <> | Subject | Re: [PATCH v13 net-next 07/11] bpf: verifier (add ability to receive verification log) |
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On 09/18/2014 05:24 PM, Alexei Starovoitov wrote: ... > solve or not. If we decide to solve it, we need to have > a plan to solve it all the way. Partial fix for size of bpf_attr > is not a plan. It's something that is not addressing the problem > completely. Little bit of help is not useful for userspace. It > would need to deal with new types, verifier differences and > other things that I mentioned earlier.
Hm, I don't think it would be a strict requirement to solve it all the way, and I think that perf_event_open() with perf_copy_attr() is not trying to do so either. It, however, is trying on a ``best effort basis'' to still load something if new features are unused by the binary (I guess you saw the comment in perf_copy_attr()).
Iff, e.g. due to new types we fail at the verifier stage, sure, that's life since we only have backwards-compatible guarantee, but in case we tried to use features we support, we're still able to load the eBPF program while right now, we're rejecting it right up-front. That's just my $0.02 ...
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