From patchwork Tue Dec 15 12:18:08 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Brendan Jackman X-Patchwork-Id: 11974737 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 9AE49C4361B for ; Tue, 15 Dec 2020 12:25:49 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6DD43224D4 for ; Tue, 15 Dec 2020 12:25:49 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729232AbgLOMXt (ORCPT ); Tue, 15 Dec 2020 07:23:49 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50380 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729214AbgLOMTs (ORCPT ); Tue, 15 Dec 2020 07:19:48 -0500 Received: from mail-qt1-x84a.google.com (mail-qt1-x84a.google.com [IPv6:2607:f8b0:4864:20::84a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E918BC061257 for ; Tue, 15 Dec 2020 04:18:32 -0800 (PST) Received: by mail-qt1-x84a.google.com with SMTP id h18so14194293qtr.2 for ; Tue, 15 Dec 2020 04:18:32 -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=GQwczh69LorlYAPQdPfIPWNyJ7hNz6c/R9pqWK+AyzI=; b=G7RyHQSIudCFMx/xGV47eTUGHkkTKXpywxoR40oEEEoe7JZ/Qr0uhFQ0DA0OWM7ycs FfMY1csZPaECxH8B/g9WZJvMQxuDln9Dg5V9kc7dOFgECu9Mi1hhxhr1QZ+4WNk90ZMD myHn5EJdmkGrsMGDFkH1FnJZxAPC8rNTUWg7UMFTsl9TQ30D9s10mNNvo9wRhqz43Ln5 tN34dqKjeW936xpNI15r0FeFFGYfXsuwvMyyCHoZn9dCBxIrCfoYdOVMjJekjJFBzFga FLndUvmtSrSEbVwY6vIkyYrDILFQG5jSDiV5oiUftsqFQsFDwnIA/FACCqpJg/genSqy BjzA== 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=GQwczh69LorlYAPQdPfIPWNyJ7hNz6c/R9pqWK+AyzI=; b=RFGt7i6IhXWuk9Btmb5YHnBtKkKFq02wXqYi1JToyENer1Vw2bdfKdA4p5csc8AWCM E7JWO2EkhC/KfRYZ0kL9vpvPlbAhGsJKZH8s0SfEtWMAXOOBNhr9VsvcgLowFHgxDpxQ 4yOKRhuub3pZGuGbGMzke5VZDa3kDKHH1gwq25bS28FERsMjUat94DZK1c8XPnNVXYnh kjhoNY2E9ld3xxNfxjztjVrzsUwrgpnYWihGkfhnS6i69rcx2JYEiGViFzC1RcT1jIaX ltxfBTWYc72yeXY3yKJJZvspS3IJDvGvc1Gt2gQypCUK66QxTj7iMigBbwbhmsGYtcax RRFQ== X-Gm-Message-State: AOAM533YO1MCQ7X2o+PDLteT2E2VZVcXFRrj0XGq0ZpRnApd7+7sBJLa RES2pcmPb4Yv4YQWFXiYzFE0nyBjZoyTwmQ0sQHPSIYpb46ueZaEuZUKgkcUYjtb8922dBgzhYv oOm/xm1sw0KZdLEGCMtvt91/DSyWP+V7pWA7lXPt6RM6obpB7zRTnEE2UwZkSbG4= X-Google-Smtp-Source: ABdhPJz7hS1PnKYUpNWqPZWjT/unGfvmNwjw9v/mMRb3FvqsWkiuAWlom8nSwl531yVuEeJEczCUJ0LfCFxsAg== 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:ad4:4e4d:: with SMTP id eb13mr16996899qvb.6.1608034711998; Tue, 15 Dec 2020 04:18:31 -0800 (PST) Date: Tue, 15 Dec 2020 12:18:08 +0000 In-Reply-To: <20201215121816.1048557-1-jackmanb@google.com> Message-Id: <20201215121816.1048557-5-jackmanb@google.com> Mime-Version: 1.0 References: <20201215121816.1048557-1-jackmanb@google.com> X-Mailer: git-send-email 2.29.2.684.gfbc64c5ab5-goog Subject: [PATCH bpf-next v5 03/11] bpf: x86: Factor out a lookup table for some ALU opcodes From: Brendan Jackman To: bpf@vger.kernel.org Cc: Alexei Starovoitov , Daniel Borkmann , Andrii Nakryiko , KP Singh , Florent Revest , linux-kernel@vger.kernel.org, Brendan Jackman , John Fastabend 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. Signed-off-by: Brendan Jackman Acked-by: John Fastabend --- 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 f15c93275a18..93f32e0ba0ef 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 */ @@ -862,15 +874,9 @@ 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; @@ -1050,12 +1056,7 @@ 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 @@ -1089,11 +1090,7 @@ 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)