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=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 775C8C433E6 for ; Thu, 14 Jan 2021 18:18:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4331923A50 for ; Thu, 14 Jan 2021 18:18:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729496AbhANSSw (ORCPT ); Thu, 14 Jan 2021 13:18:52 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58122 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725935AbhANSSt (ORCPT ); Thu, 14 Jan 2021 13:18:49 -0500 Received: from mail-qv1-xf4a.google.com (mail-qv1-xf4a.google.com [IPv6:2607:f8b0:4864:20::f4a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3DC23C0613CF for ; Thu, 14 Jan 2021 10:18:09 -0800 (PST) Received: by mail-qv1-xf4a.google.com with SMTP id c2so5257582qvs.12 for ; Thu, 14 Jan 2021 10:18:09 -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=4StJvEPcqpOoMaFQqXp2l4E4gqPLXrwP2qT6WBxKOzM=; b=GobCPeYowh3r/lLNPJLitXo++prm+HDGITq517VlpQwWxv+IKVbVnnse0Jw9P4pWKj uTaVx7oEQ/QvfRvlJD8a4w1UJD6rqIFwCsglox0IyRzeh7p6ou2NhSNr6eLh8JIdOu/H i+6ehi/Mlf6qSdLWZNtpNBy7Tq8uhLUa5n5cfRf4KK/YncdZzTDpg7f1pWwBqJlh4XZE wK3l3NTW/Aq0GZTw3cF5i4RIzjJyrzbOhJyi2QVmySeBwpicPt1+XQujMxTFvaF5YNGs E0alYo1fhFIeiKC8rKgPPGmsxvZYh3OteW+N3JE29e1XPOnmtXHICScigIQgJXXHo63K e1qg== 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=4StJvEPcqpOoMaFQqXp2l4E4gqPLXrwP2qT6WBxKOzM=; b=NcB921VMSykT3/44onrH/sVVYd7Qn9vmG9wS0Neisw1r9EAwS4ye/AyFGhDFeX1+j/ NG3nky/9AXhGucfU1TdwcQNLUehqc/dIaAelDcOiD7cYd4V59rvig/O5wW9l73b4ilqT UWTFdQBpf/cqHKTDHUwfaiGmA0ws2AxX1lE18miman75zPQfjksjoMnr87lXnZXbIQys kVJYvwjwQKisrYNsYMG37fLujTJb7n/xQwSVx0FUK9OCARa0BTJmPHjNLUN0jrLsHDkD YM7+zyltY0tfO2IM6VaYcxP2pGaxOLfskOqVSwMa+iQdhmtNsvQQY1RY+9hADSipwkP6 QyDQ== X-Gm-Message-State: AOAM531pBXDJOZavJvJkc736VPlVcZlnIT9KweaXUtva/msWpsuJMyrn uCmUW62Ph20NYfbL1zYKXoafFJNNTiNBkw== X-Google-Smtp-Source: ABdhPJygvCFqDDlF4ox29jIpa6X40Y6F/9plae/kqJpo7jaYHxrswA8ZOl2XU+Gf4hWMwhNTnYQ+RbO2hzxzKA== 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:a05:6214:727:: with SMTP id c7mr8439214qvz.22.1610648288369; Thu, 14 Jan 2021 10:18:08 -0800 (PST) Date: Thu, 14 Jan 2021 18:17:41 +0000 In-Reply-To: <20210114181751.768687-1-jackmanb@google.com> Message-Id: <20210114181751.768687-2-jackmanb@google.com> Mime-Version: 1.0 References: <20210114181751.768687-1-jackmanb@google.com> X-Mailer: git-send-email 2.30.0.284.gd98b1dd5eaa7-goog Subject: [PATCH bpf-next v7 01/11] bpf: x86: Factor out emission of ModR/M for *(reg + off) 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?q?Bj=C3=B6rn=20T=C3=B6pel?=" , John Fastabend , Yonghong Song , 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. Acked-by: John Fastabend Signed-off-by: Brendan Jackman --- arch/x86/net/bpf_jit_comp.c | 43 +++++++++++++++++++++---------------- 1 file changed, 25 insertions(+), 18 deletions(-) diff --git a/arch/x86/net/bpf_jit_comp.c b/arch/x86/net/bpf_jit_comp.c index 796506dcfc42..30526776fa78 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 +1250,8 @@ 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 */ -- 2.30.0.284.gd98b1dd5eaa7-goog