From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wr1-x443.google.com (mail-wr1-x443.google.com [IPv6:2a00:1450:4864:20::443]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by lists.bufferbloat.net (Postfix) with ESMTPS id 9818D3B2A4 for ; Wed, 22 Aug 2018 15:18:18 -0400 (EDT) Received: by mail-wr1-x443.google.com with SMTP id u12-v6so1235607wrr.4 for ; Wed, 22 Aug 2018 12:18:18 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=heistp.net; s=google; h=mime-version:subject:from:in-reply-to:date:cc :content-transfer-encoding:message-id:references:to; bh=VU8JEcACIXZ5niXC3RUHPgvsR0rLeeGZ4k0HXCTgbJE=; b=BgME6cxWbkM5acFRbqQ0N/Iqa8I9KOBuqVMkxctOJ1PZ8fgp/hNboiZU5z0SYXY7hp fNdBglPma/3rUir8sQhJE1uOsjBPIeNo1J7X3a6omc0/OlUs5fdt69Fdfm1g6IXGJNYz Q3kfew5aW3gUYRVDmam6eI8tV3vwt+P0S8ilwvccQuRJrh1Jib4JJaAR9XRDEjYUSoj7 gYJjdL95TOhjuJWd3DyMLF3JvP2DA1UC2R0LSzdeuofKhRlaBHeTpPEhwyggcYgw4eRD BKk4mHSNRfuje/uA2XfB8GGNvwNWQXYXlI0PIbqDSOuuIT3hS/V+n8PkU6je7eT4J+Xy XDcg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:subject:from:in-reply-to:date:cc :content-transfer-encoding:message-id:references:to; bh=VU8JEcACIXZ5niXC3RUHPgvsR0rLeeGZ4k0HXCTgbJE=; b=sSi6OEZtPpRBJfD2TuVDq/1ZyAnlzpWczLNMxwW9T4iWNWIlf+dFfoV+lLj7NXvnUx 4J2pdwlUKqjitL26wDQgsd5WSkANA88jFGphUENyGWDdGvKsUl8CeO9UpKAzqoYkTOme o2oCq1cYLn3yJIDVbD7pa0HaIOaIoSJv63e4uodYMmeoDHHzL5ZLvcfM4Jr72dVVIN/Z 2LFfvaUZt70Y5cEhsFsXRjD+8atGELz3vlMnfe6qQC0gorHoIbk2w6rXo5Ft0xPcgCtZ bczVy2nc1S7jLGDy+NDEA6IWAQMNTSy6LNi4PP3MimWT8T4hmi8N1gw2TdLn6PHZiAQ3 wJeg== X-Gm-Message-State: AOUpUlGjCPdRd9VVzBIzNE60pv+6udlz++XVNQ6QfnXOMiPwJojtPQsQ xUpB3dgo7qwDaVjsE6JZwAYc6w== X-Google-Smtp-Source: AA+uWPzwG3ARzq9tbkoW6YWgDSOcRlnRBqfH8EEyb9jk42bCarX2pyd4zD5KlVJpeiUtPTBVkeKuiw== X-Received: by 2002:adf:808f:: with SMTP id 15-v6mr35860833wrl.204.1534965497759; Wed, 22 Aug 2018 12:18:17 -0700 (PDT) Received: from tron.luk.heistp.net (h-1169.lbcfree.net. [185.193.85.130]) by smtp.gmail.com with ESMTPSA id q135-v6sm4724179wmd.4.2018.08.22.12.18.16 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 22 Aug 2018 12:18:17 -0700 (PDT) Content-Type: text/plain; charset=utf-8 Mime-Version: 1.0 (Mac OS X Mail 11.5 \(3445.9.1\)) From: Pete Heist In-Reply-To: <72d4eaa7-e1ae-67c9-98fa-2664d1cd52f9@iogearbox.net> Date: Wed, 22 Aug 2018 21:18:15 +0200 Cc: =?utf-8?Q?Toke_H=C3=B8iland-J=C3=B8rgensen?= , Dave Taht , Cake List Content-Transfer-Encoding: quoted-printable Message-Id: References: <20180816164423.14368-1-peterpenkov96@gmail.com> <20180816164423.14368-3-peterpenkov96@gmail.com> <5E9B5665-E115-4B8B-959A-0A4A4220046A@heistp.net> <871saqah2m.fsf@toke.dk> <72d4eaa7-e1ae-67c9-98fa-2664d1cd52f9@iogearbox.net> To: Daniel Borkmann X-Mailer: Apple Mail (2.3445.9.1) Subject: Re: [Cake] [bpf-next RFC 2/3] flow_dissector: implements eBPF parser X-BeenThere: cake@lists.bufferbloat.net X-Mailman-Version: 2.1.20 Precedence: list List-Id: Cake - FQ_codel the next generation List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 22 Aug 2018 19:18:18 -0000 > On Aug 22, 2018, at 12:41 PM, Daniel Borkmann = wrote: >=20 > On 08/22/2018 11:25 AM, Toke H=C3=B8iland-J=C3=B8rgensen wrote: >> Pete Heist writes: >>=20 >> Well, it operates on the byte code and errs on the side of safety. = I.e., >> if it can't prove your program is safe it is going to reject it. = Which >> can be less than helpful. >>=20 >> There's a mode where it can dump its state including the byte code it = is >> operating at, which can be helpful in figuring out why you get an = error. >> But it has a way to go yet compared with regular compiler error >> messages... :) >=20 > There's also llvm-objdump which can dump with annotated BPF C code and > it allows to match the verifier output line number with it. There's a > small example in the doc under LLVM section on how to get there: >=20 > https://cilium.readthedocs.io/en/latest/bpf/#llvm Thank you Daniel, that helped match the C source with the verifier = output- much easier. I=E2=80=99m still not sure why I was able to fix my problem by simply = returning my uint16_t classid through the stack rather than setting it = through a passed in pointer, but nevertheless, that works. :) Pete