From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jiong Wang Subject: [PATCH bpf-next 0/2] bpf: offer maximum packet offset info Date: Thu, 8 Nov 2018 04:08:41 -0500 Message-ID: <1541668123-9571-1-git-send-email-jiong.wang@netronome.com> Cc: netdev@vger.kernel.org, oss-drivers@netronome.com, Jiong Wang To: ast@kernel.org, daniel@iogearbox.net Return-path: Received: from mail-wm1-f66.google.com ([209.85.128.66]:37743 "EHLO mail-wm1-f66.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726133AbeKHSno (ORCPT ); Thu, 8 Nov 2018 13:43:44 -0500 Received: by mail-wm1-f66.google.com with SMTP id p2-v6so428506wmc.2 for ; Thu, 08 Nov 2018 01:09:11 -0800 (PST) Sender: netdev-owner@vger.kernel.org List-ID: The maximum packet offset accessed by one BPF program is useful information. Because sometimes there could be packet split and it is possible for some reasons (for example performance) we want to reject the BPF program if the maximum packet size would trigger such split. Normally, MTU value is treated as the maximum packet size, but one BPF program does not always access the whole packet, it could only access the head portion of the data. We could let verifier calculate the maximum packet offset ever used and record it inside prog auxiliar information structure as a new field "max_pkt_offset". Jiong Wang (2): bpf: let verifier to calculate and record max_pkt_offset nfp: bpf: relax prog rejection through max_pkt_offset drivers/net/ethernet/netronome/nfp/bpf/offload.c | 9 +++++---- include/linux/bpf.h | 1 + kernel/bpf/verifier.c | 12 ++++++++++++ 3 files changed, 18 insertions(+), 4 deletions(-) -- 2.7.4