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=-8.4 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS,USER_AGENT_MUTT 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 2879CC43218 for ; Sun, 28 Apr 2019 02:33:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E1D9920874 for ; Sun, 28 Apr 2019 02:33:49 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="ZBSt/SG+" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726224AbfD1Cdt (ORCPT ); Sat, 27 Apr 2019 22:33:49 -0400 Received: from mail-pg1-f194.google.com ([209.85.215.194]:35628 "EHLO mail-pg1-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726112AbfD1Cdt (ORCPT ); Sat, 27 Apr 2019 22:33:49 -0400 Received: by mail-pg1-f194.google.com with SMTP id h1so3455536pgs.2; Sat, 27 Apr 2019 19:33:49 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=date:from:to:cc:subject:message-id:mail-followup-to:mime-version :content-disposition:user-agent; bh=8pdP/pIbSMTEUfQnT+0vcRdQjYsBt7dW9GatpOSe0b0=; b=ZBSt/SG+mbZSNJMGMysW1W8y1DcfuWBMt+y1GCEjXy45Ycibqoks6g1MWKq1/HxzMP bSlln+KNPYYYwpZv7PvIRsaW1DmrTKl7wOG2dRigldgxY0d5jg/rMNUa8Fttst7kmURM CgUVb7R6OqNx2s/1InmJ10P36fc9r5L1v0fh8M7V8kJYQWLtsIE2hWF/bfchdJBbJkSz 2exaE1RAInpyMPe89byC/3o45z3ldMmNJDU4APVDKtcq7R9B33YH6Q3om2WeIawN9AeS wdn5FTbGhmPb5FbTpL2arESdEiGE5ja9ngXB/3d3oPy3E4NmVNqoDVPgclnYTf+7THQ2 YnHg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id :mail-followup-to:mime-version:content-disposition:user-agent; bh=8pdP/pIbSMTEUfQnT+0vcRdQjYsBt7dW9GatpOSe0b0=; b=oHQqRSrreZ6ZdUk/2md3Qm7KUyTjOfZgxh9ZU9M6VDVeV1kuJSSnikQ0onKgVLMjHE NZZ4qJaW6Z4P6szvuqwVz7ruLLGBoQjog5UhL093gPuJqkQMxBBTpVLT5RJakYI/VzxE WSSPo1m4lvmm/fBkH8FAOWEKRwqZNa4j59zBEB/07Y0DKeGVfYv1lb1gDksRm1WtrVjU 59A888kY0QRcQe2ympT9svfPDS5wlBeOel/bilk3s70bJEtqv3vDHb/PzIG6gOEBNHuo n1C4lUxaFg1g3+4yluf+cujC0B33HPWb5eyBeLyzxY5fJIGyvJmEP/8znw8ntM7ldy1P XshQ== X-Gm-Message-State: APjAAAU3oYfCdyIkUtT88v53XutPQEb7/mIf0dBVi+bC1arAIKUFGbye FK8oqBewfPP9FT7YZI0ZxJg= X-Google-Smtp-Source: APXvYqxZvLvOc3rGYU2DbViR+D8bUUYIlr9cbTBVek3/r2LkNuOFbboTkGmUNKlIo85ASnXVLCgCbQ== X-Received: by 2002:a63:d512:: with SMTP id c18mr11227831pgg.252.1556418828679; Sat, 27 Apr 2019 19:33:48 -0700 (PDT) Received: from udknight.localhost ([183.250.89.86]) by smtp.gmail.com with ESMTPSA id l19sm39348312pff.1.2019.04.27.19.33.47 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Sat, 27 Apr 2019 19:33:48 -0700 (PDT) Received: from udknight.localhost (localhost [127.0.0.1]) by udknight.localhost (8.14.9/8.14.4) with ESMTP id x3S2XLSf029356; Sun, 28 Apr 2019 10:33:23 +0800 Received: (from root@localhost) by udknight.localhost (8.14.9/8.14.9/Submit) id x3S2X293029347; Sun, 28 Apr 2019 10:33:02 +0800 Date: Sun, 28 Apr 2019 10:33:02 +0800 From: Wang YanQing To: daniel@iogearbox.net Cc: 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 Subject: [PATCH] bpf, x32: Fix bug for BPF_ALU64 | BPF_NEG Message-ID: <20190428023302.GA29326@udknight> Mail-Followup-To: Wang YanQing , daniel@iogearbox.net, 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 MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.7.1 (2016-10-04) Sender: bpf-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org 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 --- arch/x86/net/bpf_jit_comp32.c | 19 ++++++------------- 1 file changed, 6 insertions(+), 13 deletions(-) diff --git a/arch/x86/net/bpf_jit_comp32.c b/arch/x86/net/bpf_jit_comp32.c index 8097b88..b29e82f 100644 --- a/arch/x86/net/bpf_jit_comp32.c +++ b/arch/x86/net/bpf_jit_comp32.c @@ -700,19 +700,12 @@ static inline void emit_ia32_neg64(const u8 dst[], bool dstk, u8 **pprog) STACK_VAR(dst_hi)); } - /* xor ecx,ecx */ - EMIT2(0x31, add_2reg(0xC0, IA32_ECX, IA32_ECX)); - /* sub dreg_lo,ecx */ - EMIT2(0x2B, add_2reg(0xC0, dreg_lo, IA32_ECX)); - /* mov dreg_lo,ecx */ - EMIT2(0x89, add_2reg(0xC0, dreg_lo, IA32_ECX)); - - /* xor ecx,ecx */ - EMIT2(0x31, add_2reg(0xC0, IA32_ECX, IA32_ECX)); - /* sbb dreg_hi,ecx */ - EMIT2(0x19, add_2reg(0xC0, dreg_hi, IA32_ECX)); - /* mov dreg_hi,ecx */ - EMIT2(0x89, add_2reg(0xC0, dreg_hi, IA32_ECX)); + /* neg dreg_lo */ + EMIT2(0xF7, add_1reg(0xD8, dreg_lo)); + /* adc dreg_hi,0x0 */ + EMIT3(0x83, add_1reg(0xD0, dreg_hi), 0x00); + /* neg dreg_hi */ + EMIT2(0xF7, add_1reg(0xD8, dreg_hi)); if (dstk) { /* mov dword ptr [ebp+off],dreg_lo */ -- 1.8.5.6.2.g3d8a54e.dirty