From: David Miller <davem@davemloft.net>
To: ast@plumgrid.com
Cc: mingo@kernel.org, torvalds@linux-foundation.org,
luto@amacapital.net, rostedt@goodmis.org, dborkman@redhat.com,
chema@google.com, edumazet@google.com, a.p.zijlstra@chello.nl,
brendan.d.gregg@gmail.com, namhyung@kernel.org, hpa@zytor.com,
akpm@linux-foundation.org, keescook@chromium.org,
linux-api@vger.kernel.org, netdev@vger.kernel.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH v6 net-next 1/6] net: filter: add "load 64-bit immediate" eBPF instruction
Date: Mon, 25 Aug 2014 18:06:21 -0700 (PDT) [thread overview]
Message-ID: <20140825.180621.1003932711320755950.davem@davemloft.net> (raw)
In-Reply-To: <1409014858-1410-2-git-send-email-ast@plumgrid.com>
From: Alexei Starovoitov <ast@plumgrid.com>
Date: Mon, 25 Aug 2014 18:00:53 -0700
> add BPF_LD_IMM64 instruction to load 64-bit immediate value into a register.
I think you need to rethink this.
I understand that you want to be able to compile arbitrary C code into
eBPF, but you have to restrict strongly what data the eBPF code can get
to.
Arbitrary pointer loads is asking for trouble.
Instead I would rather you look into a model like what the quake
engine uses for it's VM.
Namely, the program can do loads and stores from/to a data section,
but all of them are validated to be in the range of the VM program's
image.
eBPF programs should only be able to access things using either:
1) Well defined entry/exit points for control transfer
2) Load/Store within a private limited data segment range used
only by the eBPF program
I don't want the eBPF program to be able to get "out of it's box"
in any way shape or form.
And besides, you're only making this thing as an optimization right?
next prev parent reply other threads:[~2014-08-26 1:06 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-08-26 1:00 [PATCH v6 net-next 0/6] introduce BPF syscall Alexei Starovoitov
2014-08-26 1:00 ` [PATCH v6 net-next 1/6] net: filter: add "load 64-bit immediate" eBPF instruction Alexei Starovoitov
2014-08-26 1:06 ` David Miller [this message]
2014-08-26 1:35 ` Alexei Starovoitov
2014-08-26 1:38 ` Andy Lutomirski
2014-08-26 1:53 ` Alexei Starovoitov
2014-08-26 1:54 ` Andy Lutomirski
2014-08-26 2:02 ` Alexei Starovoitov
2014-08-26 4:12 ` Alexei Starovoitov
2014-08-26 1:00 ` [PATCH v6 net-next 2/6] net: filter: split filter.h and expose eBPF to user space Alexei Starovoitov
2014-08-26 1:00 ` [PATCH v6 net-next 3/6] bpf: introduce syscall(BPF, ...) and BPF maps Alexei Starovoitov
2014-08-26 1:00 ` [PATCH v6 net-next 4/6] bpf: enable bpf syscall on x64 and i386 Alexei Starovoitov
2014-08-26 1:07 ` David Miller
2014-08-26 1:43 ` Alexei Starovoitov
2014-08-26 7:45 ` Ingo Molnar
2014-08-26 16:29 ` Alexei Starovoitov
2014-08-26 3:52 ` Stephen Hemminger
2014-08-26 4:24 ` Alexei Starovoitov
2014-08-26 7:46 ` Ingo Molnar
2014-08-26 8:00 ` Daniel Borkmann
2014-08-26 8:02 ` Ingo Molnar
2014-08-26 16:40 ` Alexei Starovoitov
2014-08-26 1:00 ` [PATCH v6 net-next 5/6] bpf: add lookup/update/delete/iterate methods to BPF maps Alexei Starovoitov
2014-08-26 1:00 ` [PATCH v6 net-next 6/6] bpf: add hashtable type of " Alexei Starovoitov
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