From patchwork Thu Dec 3 16:02:35 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Brendan Jackman X-Patchwork-Id: 11949059 X-Patchwork-Delegate: bpf@iogearbox.net 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=-26.3 required=3.0 tests=BAYES_00,DKIMWL_WL_MED, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_GIT,USER_IN_DEF_DKIM_WL 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 663AFC4167B for ; Thu, 3 Dec 2020 16:05:07 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 125E0207A9 for ; Thu, 3 Dec 2020 16:05:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2436649AbgLCQEc (ORCPT ); Thu, 3 Dec 2020 11:04:32 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54820 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2436594AbgLCQEb (ORCPT ); Thu, 3 Dec 2020 11:04:31 -0500 Received: from mail-wm1-x34a.google.com (mail-wm1-x34a.google.com [IPv6:2a00:1450:4864:20::34a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E8C84C08E85F for ; Thu, 3 Dec 2020 08:03:19 -0800 (PST) Received: by mail-wm1-x34a.google.com with SMTP id l5so1503462wmi.4 for ; Thu, 03 Dec 2020 08:03:19 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=sender:date:in-reply-to:message-id:mime-version:references:subject :from:to:cc; bh=2Q2lne0lXLlvS3rxE7b9vuMB9y2K2LQZIZMl35a4JXk=; b=vcJ4+79//CdUXs9AdX9SPf05uB/G63aUP5cG4KzyXo/tvvxbbWt6n+3Qx73s7O3Dpb v1L95XWtfWCpKts52CEIq8d2OwA88kBC67aOerfydzROVWbBDykc1fntIekGZgB/OjKX sR3DEEv/H6mFORpM0vcEOlh3GxtOvqkMfy/89+7ORcFWEBgSAHd8U0pWVWjwYSsmym14 +FAYpqcpU5vR/l8ZboEngQxDOMgFyrXSemfzZloks/lv/qLV0QZxN7kjkm/Hz18U3ugR ffZn/FTZkJVMZ2GVSfcGAsWqtz8S4AfL15VPP2ma04FHcF249DECceWDLAGs5TuAId8+ UdBQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:sender:date:in-reply-to:message-id:mime-version :references:subject:from:to:cc; bh=2Q2lne0lXLlvS3rxE7b9vuMB9y2K2LQZIZMl35a4JXk=; b=Ym4qsVlwgFPmok4usZrTI1eRMM+8HV3fuCYXrFtwj0ZrhNiRCr+KIH3Ps+RwAwOfKs OmaciDukejrGP2FqF8AM72uv6NTUfd3nvJzTn6684mbVIvEKgotq68iojSTcc6IIJWVA f9BLzRAFv4Z9CFMLO8L+jKCVFC+iBGUh9fGEtRgsWxW5D6D/gtS/5+mrbXiXkz25WfAq eEYgcZshtBBXK1y05X45nUIuWrjC1HtfM+yMIQfW/g9+gYxcS7co1MjtrNg+KoaMZHs3 1FCQoq3vXtkMdW8Jmf8zo9uKW0p1vR3nTEECYbxrP/v49ZSjYWEr0eEIb+jB2G/sS4Jv YfcQ== X-Gm-Message-State: AOAM532MHVmKdMfX7g13ZDJL8DAcNqbX71cYbirSS56V6TDsGVOQBj0/ KsCJ1ROWoZ1yP7QXzMTWLcziWDqAUUaliKwFgMsECSxTMbjxHA3yKjGwuexAkkyj16RzI4zgGrs BKDmMBtHhhOelXALfHLYSupvxczTp5b1WT2SRpWihFjaQTwFUkCf1VjMyL9C6dg0= X-Google-Smtp-Source: ABdhPJxfEnzmya6LLLPB13rIOUwk19exrmqubviCzrWxYezPhfMxbEy9yh2kt8fPqjD23AGjw7yuMAHbib0fbA== Sender: "jackmanb via sendgmr" X-Received: from beeg.c.googlers.com ([fda3:e722:ac3:10:28:9cb1:c0a8:11db]) (user=jackmanb job=sendgmr) by 2002:a7b:c8c8:: with SMTP id f8mr1117092wml.0.1607011397822; Thu, 03 Dec 2020 08:03:17 -0800 (PST) Date: Thu, 3 Dec 2020 16:02:35 +0000 In-Reply-To: <20201203160245.1014867-1-jackmanb@google.com> Message-Id: <20201203160245.1014867-5-jackmanb@google.com> Mime-Version: 1.0 References: <20201203160245.1014867-1-jackmanb@google.com> X-Mailer: git-send-email 2.29.2.454.gaff20da3a2-goog Subject: [PATCH bpf-next v3 04/14] bpf: x86: Factor out a lookup table for some ALU opcodes From: Brendan Jackman To: bpf@vger.kernel.org Cc: Alexei Starovoitov , Yonghong Song , Daniel Borkmann , KP Singh , Florent Revest , linux-kernel@vger.kernel.org, Jann Horn , Brendan Jackman Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org X-Patchwork-Delegate: bpf@iogearbox.net A later commit will need to lookup a subset of these opcodes. To avoid duplicating code, pull out a table. The shift opcodes won't be needed by that later commit, but they're already duplicated, so fold them into the table anyway. Change-Id: Ia6888f9fa65da6225c33b530ea16911bf2f70750 Signed-off-by: Brendan Jackman --- arch/x86/net/bpf_jit_comp.c | 33 +++++++++++++++------------------ 1 file changed, 15 insertions(+), 18 deletions(-) diff --git a/arch/x86/net/bpf_jit_comp.c b/arch/x86/net/bpf_jit_comp.c index 171ce539f6b9..ee7905051ee9 100644 --- a/arch/x86/net/bpf_jit_comp.c +++ b/arch/x86/net/bpf_jit_comp.c @@ -205,6 +205,18 @@ static u8 add_2reg(u8 byte, u32 dst_reg, u32 src_reg) return byte + reg2hex[dst_reg] + (reg2hex[src_reg] << 3); } +/* Some 1-byte opcodes for binary ALU operations */ +static u8 simple_alu_opcodes[] = { + [BPF_ADD] = 0x01, + [BPF_SUB] = 0x29, + [BPF_AND] = 0x21, + [BPF_OR] = 0x09, + [BPF_XOR] = 0x31, + [BPF_LSH] = 0xE0, + [BPF_RSH] = 0xE8, + [BPF_ARSH] = 0xF8, +}; + static void jit_fill_hole(void *area, unsigned int size) { /* Fill whole space with INT3 instructions */ @@ -878,15 +890,9 @@ static int do_jit(struct bpf_prog *bpf_prog, int *addrs, u8 *image, case BPF_ALU64 | BPF_AND | BPF_X: case BPF_ALU64 | BPF_OR | BPF_X: case BPF_ALU64 | BPF_XOR | BPF_X: - switch (BPF_OP(insn->code)) { - case BPF_ADD: b2 = 0x01; break; - case BPF_SUB: b2 = 0x29; break; - case BPF_AND: b2 = 0x21; break; - case BPF_OR: b2 = 0x09; break; - case BPF_XOR: b2 = 0x31; break; - } maybe_emit_mod(&prog, dst_reg, src_reg, BPF_CLASS(insn->code) == BPF_ALU64); + b2 = simple_alu_opcodes[BPF_OP(insn->code)]; EMIT2(b2, add_2reg(0xC0, dst_reg, src_reg)); break; @@ -1063,12 +1069,7 @@ static int do_jit(struct bpf_prog *bpf_prog, int *addrs, u8 *image, else if (is_ereg(dst_reg)) EMIT1(add_1mod(0x40, dst_reg)); - switch (BPF_OP(insn->code)) { - case BPF_LSH: b3 = 0xE0; break; - case BPF_RSH: b3 = 0xE8; break; - case BPF_ARSH: b3 = 0xF8; break; - } - + b3 = simple_alu_opcodes[BPF_OP(insn->code)]; if (imm32 == 1) EMIT2(0xD1, add_1reg(b3, dst_reg)); else @@ -1102,11 +1103,7 @@ static int do_jit(struct bpf_prog *bpf_prog, int *addrs, u8 *image, else if (is_ereg(dst_reg)) EMIT1(add_1mod(0x40, dst_reg)); - switch (BPF_OP(insn->code)) { - case BPF_LSH: b3 = 0xE0; break; - case BPF_RSH: b3 = 0xE8; break; - case BPF_ARSH: b3 = 0xF8; break; - } + b3 = simple_alu_opcodes[BPF_OP(insn->code)]; EMIT2(0xD3, add_1reg(b3, dst_reg)); if (src_reg != BPF_REG_4)