From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-4.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id F2AB5C04AA8 for ; Wed, 1 May 2019 21:44:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id CA241208C3 for ; Wed, 1 May 2019 21:44:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726282AbfEAVoG (ORCPT ); Wed, 1 May 2019 17:44:06 -0400 Received: from www62.your-server.de ([213.133.104.62]:42956 "EHLO www62.your-server.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726231AbfEAVoF (ORCPT ); Wed, 1 May 2019 17:44:05 -0400 Received: from [78.46.172.2] (helo=sslproxy05.your-server.de) by www62.your-server.de with esmtpsa (TLSv1.2:DHE-RSA-AES256-GCM-SHA384:256) (Exim 4.89_1) (envelope-from ) id 1hLx14-0008OJ-3n; Wed, 01 May 2019 23:43:50 +0200 Received: from [173.228.226.134] (helo=localhost.localdomain) by sslproxy05.your-server.de with esmtpsa (TLSv1.2:ECDHE-RSA-AES256-GCM-SHA384:256) (Exim 4.89) (envelope-from ) id 1hLx13-000M1d-Ia; Wed, 01 May 2019 23:43:49 +0200 Subject: Re: [PATCH] bpf, x32: Fix bug for BPF_ALU64 | BPF_NEG To: Wang YanQing , ast@kernel.org, davem@davemloft.net, kuznet@ms2.inr.ac.ru, tglx@linutronix.de, netdev@vger.kernel.org, bpf@vger.kernel.org, linux-kernel@vger.kernel.org References: <20190428023302.GA29326@udknight> From: Daniel Borkmann Message-ID: <091c2ed4-a07f-cc75-7b18-1c7cb7068652@iogearbox.net> Date: Wed, 1 May 2019 23:43:45 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.3.0 MIME-Version: 1.0 In-Reply-To: <20190428023302.GA29326@udknight> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit X-Authenticated-Sender: daniel@iogearbox.net X-Virus-Scanned: Clear (ClamAV 0.100.3/25436/Wed May 1 09:58:19 2019) Sender: bpf-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org On 04/28/2019 04:33 AM, Wang YanQing wrote: > The current implementation has two errors: > 1: The second xor instruction will clear carry flag which > is necessary for following sbb instruction. > 2: The select coding for sbb instruction is wrong, the coding > is "sbb dreg_hi,ecx", but what we need is "sbb ecx,dreg_hi". > > This patch rewrites the implementation and fixes the errors. > > This patch fixes below errors reported by bpf/test_verifier in x32 > platform when the jit is enabled: > " > 0: (b4) w1 = 4 > 1: (b4) w2 = 4 > 2: (1f) r2 -= r1 > 3: (4f) r2 |= r1 > 4: (87) r2 = -r2 > 5: (c7) r2 s>>= 63 > 6: (5f) r1 &= r2 > 7: (bf) r0 = r1 > 8: (95) exit > processed 9 insns (limit 131072), stack depth 0 > 0: (b4) w1 = 4 > 1: (b4) w2 = 4 > 2: (1f) r2 -= r1 > 3: (4f) r2 |= r1 > 4: (87) r2 = -r2 > 5: (c7) r2 s>>= 63 > 6: (5f) r1 &= r2 > 7: (bf) r0 = r1 > 8: (95) exit > processed 9 insns (limit 131072), stack depth 0 > ...... > Summary: 1189 PASSED, 125 SKIPPED, 15 FAILED > " > > Signed-off-by: Wang YanQing Applied, thanks!