From patchwork Tue Jan 12 15:42:27 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Brendan Jackman X-Patchwork-Id: 12013831 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=unavailable 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 26363C43331 for ; Tue, 12 Jan 2021 15:44:55 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id CEFDB23131 for ; Tue, 12 Jan 2021 15:44:54 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2403868AbhALPoC (ORCPT ); Tue, 12 Jan 2021 10:44:02 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52920 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729397AbhALPoB (ORCPT ); Tue, 12 Jan 2021 10:44:01 -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 E15D7C0617A4 for ; Tue, 12 Jan 2021 07:42:46 -0800 (PST) Received: by mail-wm1-x34a.google.com with SMTP id w204so640091wmb.1 for ; Tue, 12 Jan 2021 07:42:46 -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=ZTGQEWpWAiK+AJl9ZPeXz4p19Gfj2HCZL+15XnqwBus=; b=qK+5Htm26MeU6+gJ3X7VhdVrGERTVcewU4/bvrNs3gnN7qHBnnpNIr5SWl7979mEu3 YgQL252A06kXXddF3PXFbB1XGuNBQk0eYNzUOhxqglEkhuWwaDFCBnko/vwbbJTW4EIQ 2J9I+BjQABZ+gJ75bG2pJR5HQIHqmnbwNR7W5cHPvO4YNnA6jlRKSPLpX/js/CbdDwn+ RRmooIqOvwszs2NOzfb/zUCn9fUX+waqwGCRNzDqawXaizDxLECSd67Us+nQF/jN0+Vd tf9+Tav6a4UjBTtoIRHmBPY/1o2/BVOp9hQcaKixulXG7ZUREoMUesL1HjviEBMb+VBq XXJA== 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=ZTGQEWpWAiK+AJl9ZPeXz4p19Gfj2HCZL+15XnqwBus=; b=VdW0lYRgNsIlLu92H/6sX7VgqvOHr3oFcxFBDbXOQZu2Q2lQ/rZ7xKmngZl+NjCRfo V6/9ii/GF1OJfkj8UMSxcra8+PEKRWCoInHf39Nd59mgliKphjX0+IL+TKNNH3rcY1yR cRphDXWLznyybtozHDkUOwGTH2Jnw3b/BxsAh1iT2VxPmcDhgGLf0nWlTCTF61TV08kB zgaCV3F/6KCUy3psIndfqPMFKckh3pIPSv6puJcrFYDlZPr6z4odSsHVDjWUhZLM/RjZ xJlhAZXd67wu+qQ3XvU2NXCoiAvjo9fyPpJkIfAfGqIsvVJieNjY+EkpzBz510FlwhvO f1cA== X-Gm-Message-State: AOAM530r3DwOcMaVJf9JQQhb8U3OU8hC0ZqiKuyOGYZL1yHdk7wYVaEB wL4NKSHPnC+KBpTr8wdN5TABp93rkN+LYmn//GGp94Xy94Sp8zFMERNuzDqQi+/5QyKtypI5wQ2 IIJoBY9QbG1hKbGTDZdd+aZHczjCQpbFs5wb7XUwvrMWFZsJp+PohspDns0H9wiQ= X-Google-Smtp-Source: ABdhPJyW6XQ55d6NBrHqiCTtElubyhVpadacjAlnkBOxd1utVgSsfx15a4mip98cGUVXfCDOihGuVvYpYn8ZvA== Sender: "jackmanb via sendgmr" X-Received: from beeg.c.googlers.com ([fda3:e722:ac3:cc00:28:9cb1:c0a8:11db]) (user=jackmanb job=sendgmr) by 2002:a1c:4489:: with SMTP id r131mr4256433wma.24.1610466165562; Tue, 12 Jan 2021 07:42:45 -0800 (PST) Date: Tue, 12 Jan 2021 15:42:27 +0000 In-Reply-To: <20210112154235.2192781-1-jackmanb@google.com> Message-Id: <20210112154235.2192781-4-jackmanb@google.com> Mime-Version: 1.0 References: <20210112154235.2192781-1-jackmanb@google.com> X-Mailer: git-send-email 2.30.0.284.gd98b1dd5eaa7-goog Subject: [PATCH bpf-next v6 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, " =?utf-8?b?QmrDtnJuIFTDtnBlbA==?= " , John Fastabend , Yonghong Song , 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. 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)