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=-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 91E3DC4167B for ; Thu, 3 Dec 2020 16:04:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 52146207AA for ; Thu, 3 Dec 2020 16:04:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2389301AbgLCQDx (ORCPT ); Thu, 3 Dec 2020 11:03:53 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54710 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2389264AbgLCQDx (ORCPT ); Thu, 3 Dec 2020 11:03:53 -0500 Received: from mail-ed1-x54a.google.com (mail-ed1-x54a.google.com [IPv6:2a00:1450:4864:20::54a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id CB7E1C061A52 for ; Thu, 3 Dec 2020 08:03:12 -0800 (PST) Received: by mail-ed1-x54a.google.com with SMTP id p17so1123016edx.22 for ; Thu, 03 Dec 2020 08:03:12 -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=Avg0eeJcHmqqPj9kVJA02JQI6kCCnbENGcaSwjHPh3w=; b=IFtG6Xqy/HIL7S+ghxb9zqtTZkaezrwpXDJBy+3NhXnBPgctfC1hoVNdopgr4BhGoC xzpDUUuz3fCW9BvtFLchGmQKgpZGjmllAl8u+px+FtAFfEWrGXhD7SbeMntG8H11hI+K jS1TWr+CpOYtIJV/yDofrOQfh3QTk3hYvF13V6xqAem/6EJpHqxHDK55/+b0qAf6J95Z 9P5q8If3f/sXCZjtoF7mC8NFePzRNhxQvixpoBePhvGHz5p3cELZMOdIkSM+Wt+BSfbU L+ZmfXazlhg+aVDILuLWuaD6Jt6sKMAilPhhAxLk6vVNFfS/E8CFlpeUeqmohyWGkYch l6SQ== 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=Avg0eeJcHmqqPj9kVJA02JQI6kCCnbENGcaSwjHPh3w=; b=B+K6uk+tmLuRlwuVLwcOStEeDh/NBlG+8MnwpqrKCZW1sogqrPqVfNvUr3rhl0fbFF BYjs4GB5XQvP01ouAuOB4QKdJIJEaxUsavwgwm+0o9UjLsTnk/RQdn1pIYJ2jkxE/J3l YlEmuZ3sdo42ckhw30RwUMhcBpJ6op8D9UzV36SEsKO6e5+dOlHKVWQujx+c85yaAvxZ 71xcNMTv9LP+UNmn0rzFb582ehJv3JgwvDER8x3yxSADeVw1fE3aiE14Lmqh6juNuXq6 tKrLxRzLYLLa5b/DWamPCFnnyaNYiJaARBaymd2uHHqFDZ4TuGejbC98I/Od/1V+LtmU JJ8A== X-Gm-Message-State: AOAM532qveP2cKCNioWOuDdsclaYXx8UkvBXJrmnyqf6EijwK1117CkG RLWmSH3tPSz0NnIr13pPIcdeVzuBBSGVnA== X-Google-Smtp-Source: ABdhPJzuT8NP2QZqSfs5VGNZ/PtzZs7jUmyA8fllEw8LdS22rMv2aLa+JH08iaFSAytfjR0iwSBz1ys9ErjX3w== 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:a17:906:f894:: with SMTP id lg20mr3079697ejb.348.1607011391181; Thu, 03 Dec 2020 08:03:11 -0800 (PST) Date: Thu, 3 Dec 2020 16:02:32 +0000 In-Reply-To: <20201203160245.1014867-1-jackmanb@google.com> Message-Id: <20201203160245.1014867-2-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 01/14] bpf: x86: Factor out emission of ModR/M for *(reg + off) 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 Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The case for JITing atomics is about to get more complicated. Let's factor out some common code to make the review and result more readable. NB the atomics code doesn't yet use the new helper - a subsequent patch will add its use as a side-effect of other changes. Signed-off-by: Brendan Jackman Change-Id: I1510c7eb0132ff9262fea92ce1839243b6d33372 --- arch/x86/net/bpf_jit_comp.c | 42 +++++++++++++++++++++---------------- 1 file changed, 24 insertions(+), 18 deletions(-) diff --git a/arch/x86/net/bpf_jit_comp.c b/arch/x86/net/bpf_jit_comp.c index 796506dcfc42..cc818ed7c2b9 100644 --- a/arch/x86/net/bpf_jit_comp.c +++ b/arch/x86/net/bpf_jit_comp.c @@ -681,6 +681,27 @@ static void emit_mov_reg(u8 **pprog, bool is64, u32 dst_reg, u32 src_reg) *pprog = prog; } +/* Emit the suffix (ModR/M etc) for addressing *(ptr_reg + off) and val_reg */ +static void emit_insn_suffix(u8 **pprog, u32 ptr_reg, u32 val_reg, int off) +{ + u8 *prog = *pprog; + int cnt = 0; + + if (is_imm8(off)) { + /* 1-byte signed displacement. + * + * If off == 0 we could skip this and save one extra byte, but + * special case of x86 R13 which always needs an offset is not + * worth the hassle + */ + EMIT2(add_2reg(0x40, ptr_reg, val_reg), off); + } else { + /* 4-byte signed displacement */ + EMIT1_off32(add_2reg(0x80, ptr_reg, val_reg), off); + } + *pprog = prog; +} + /* LDX: dst_reg = *(u8*)(src_reg + off) */ static void emit_ldx(u8 **pprog, u32 size, u32 dst_reg, u32 src_reg, int off) { @@ -708,15 +729,7 @@ static void emit_ldx(u8 **pprog, u32 size, u32 dst_reg, u32 src_reg, int off) EMIT2(add_2mod(0x48, src_reg, dst_reg), 0x8B); break; } - /* - * If insn->off == 0 we can save one extra byte, but - * special case of x86 R13 which always needs an offset - * is not worth the hassle - */ - if (is_imm8(off)) - EMIT2(add_2reg(0x40, src_reg, dst_reg), off); - else - EMIT1_off32(add_2reg(0x80, src_reg, dst_reg), off); + emit_insn_suffix(&prog, src_reg, dst_reg, off); *pprog = prog; } @@ -751,10 +764,7 @@ static void emit_stx(u8 **pprog, u32 size, u32 dst_reg, u32 src_reg, int off) EMIT2(add_2mod(0x48, dst_reg, src_reg), 0x89); break; } - if (is_imm8(off)) - EMIT2(add_2reg(0x40, dst_reg, src_reg), off); - else - EMIT1_off32(add_2reg(0x80, dst_reg, src_reg), off); + emit_insn_suffix(&prog, dst_reg, src_reg, off); *pprog = prog; } @@ -1240,11 +1250,7 @@ st: if (is_imm8(insn->off)) goto xadd; case BPF_STX | BPF_XADD | BPF_DW: EMIT3(0xF0, add_2mod(0x48, dst_reg, src_reg), 0x01); -xadd: if (is_imm8(insn->off)) - EMIT2(add_2reg(0x40, dst_reg, src_reg), insn->off); - else - EMIT1_off32(add_2reg(0x80, dst_reg, src_reg), - insn->off); +xadd: emit_modrm_dstoff(&prog, dst_reg, src_reg, insn->off); break; /* call */ -- 2.29.2.454.gaff20da3a2-goog