From: Andi Kleen <ak@linux.intel.com>
To: speck@linutronix.de
Subject: [MODERATED] Re: Generic eBPF hardening
Date: Thu, 17 May 2018 16:39:07 -0700 [thread overview]
Message-ID: <20180517233907.GD4486@tassilo.jf.intel.com> (raw)
In-Reply-To: <20180517232115.mwmns6w6t32mjeze@ast-mbp>
> I disagree with 'cheap' assessment.
> The main use case for unprivileged bpf is so_reuseport and socket filters.
> It's critical path of networking receive side.
> Adding lfence after every program won't be cheap.
I don't think we need any lfence at all. It makes no difference for
stack reuse.
All we need is stack clear for the locations that are script controlled.
That should be quite cheap.
Register clearing would be nice, and should be also cheap.
-Andi
next prev parent reply other threads:[~2018-05-17 23:39 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-05-17 20:55 [MODERATED] Generic eBPF hardening Dave Hansen
2018-05-17 22:22 ` [MODERATED] " Alexei Starovoitov
2018-05-17 22:54 ` Andi Kleen
2018-05-17 23:21 ` Alexei Starovoitov
2018-05-17 23:39 ` Andi Kleen [this message]
2018-05-18 18:18 ` Dave Hansen
2018-05-18 22:26 ` Alexei Starovoitov
2018-05-17 23:13 ` Dave Hansen
2018-05-17 23:24 ` Alexei Starovoitov
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