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 19E85C433E6 for ; Tue, 12 Jan 2021 15:43:57 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D806023131 for ; Tue, 12 Jan 2021 15:43:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2404136AbhALPn2 (ORCPT ); Tue, 12 Jan 2021 10:43:28 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52790 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2403889AbhALPnZ (ORCPT ); Tue, 12 Jan 2021 10:43:25 -0500 Received: from mail-wr1-x449.google.com (mail-wr1-x449.google.com [IPv6:2a00:1450:4864:20::449]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D40ADC06179F for ; Tue, 12 Jan 2021 07:42:44 -0800 (PST) Received: by mail-wr1-x449.google.com with SMTP id v5so1333752wrr.0 for ; Tue, 12 Jan 2021 07:42:44 -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=e3m9lxWPd1akNGwOE664d3Ddb1cr1DVVkpzRKRihJEs=; b=RwUEjOYOfTGhlF9n+6uI36gGPxJutfvmCHnPnbf0DWHdej0SkQVwCzsQfQ6vvbSBM/ bqKwKEFzFJYf//XCDtfmzwW0Xn/jjZnnU/dPFeWvewXeuaQim4oYQMOTNTkkCQtIxsw+ bdxG2necjEFDvi90OWcee4/y8pL76o9HPf1nhn6vkmzTzoCdgWTCxCMuckYiTsmji01+ 5YF3VbjKchPFOTQdVRGQt/jJhA5AIY8CTbzJg+G5rtc7olhrHQeGmsf03F4w5wNqZXaJ ZZwsAHe4PzD/GEQJpYQvDJes3l3y+8koO12yWCneVhQpWQR0n1CqqOYgiD4B9tVhBYqL B3CQ== 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=e3m9lxWPd1akNGwOE664d3Ddb1cr1DVVkpzRKRihJEs=; b=FJvVoyF1nXDbe1+6UeQTZZ/I41lPtiAiga5m72GWtdcVk6EljQ20+uFXylbpBRxpOM jC6X9WEN3r6AH5zxaquT5nqnXf5368iTFmnlkg6oZrOnYBzS/hgR8b+tQ3A8WKAOLYdA MZFnouih4azTqWtx+TSWArFLdvPPGb9At/0hSVBNkW+2DyNrJIjGpa29MJGX1Saq+Fes H8H9gz2wjgwXTUJtuW9/cmuskpfPwOWk//aYHFZczrl6RZTNuUMhVyGquJ78xovDNv8s PgweNbm5pyt3j11Wzglvz1aONZ2Adp2GXZb1EhDe/lJsWqfsVN245H+iQBZEgS0EOt9V zHvg== X-Gm-Message-State: AOAM531dvP+HCZJGQGu2vSmmhMXYx6Tz8bWJPLpKU5aKT9Pd2Zkg+6Bj KsFHWsmkeHWwtUFAbXOl3RM165bnVl9BOg== X-Google-Smtp-Source: ABdhPJzmUbNZVgQEEl9a1+yS6EbVAnyPPnivhSVA6Z3pRfWi9Sq0xYQIeKEiP2FKujS3XJA4Qu/HQD+q4kc6+w== 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:adf:fb85:: with SMTP id a5mr4955537wrr.331.1610466163355; Tue, 12 Jan 2021 07:42:43 -0800 (PST) Date: Tue, 12 Jan 2021 15:42:26 +0000 In-Reply-To: <20210112154235.2192781-1-jackmanb@google.com> Message-Id: <20210112154235.2192781-3-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 02/11] bpf: x86: Factor out emission of REX byte 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 JIT case for encoding atomic ops is about to get more complicated. In order to make the review & resulting code easier, let's factor out some shared helpers. Signed-off-by: Brendan Jackman Acked-by: John Fastabend --- arch/x86/net/bpf_jit_comp.c | 39 ++++++++++++++++++++++--------------- 1 file changed, 23 insertions(+), 16 deletions(-) diff --git a/arch/x86/net/bpf_jit_comp.c b/arch/x86/net/bpf_jit_comp.c index 30526776fa78..f15c93275a18 100644 --- a/arch/x86/net/bpf_jit_comp.c +++ b/arch/x86/net/bpf_jit_comp.c @@ -702,6 +702,21 @@ static void emit_insn_suffix(u8 **pprog, u32 ptr_reg, u32 val_reg, int off) *pprog = prog; } +/* + * Emit a REX byte if it will be necessary to address these registers + */ +static void maybe_emit_mod(u8 **pprog, u32 dst_reg, u32 src_reg, bool is64) +{ + u8 *prog = *pprog; + int cnt = 0; + + if (is64) + EMIT1(add_2mod(0x48, dst_reg, src_reg)); + else if (is_ereg(dst_reg) || is_ereg(src_reg)) + EMIT1(add_2mod(0x40, dst_reg, src_reg)); + *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) { @@ -854,10 +869,8 @@ static int do_jit(struct bpf_prog *bpf_prog, int *addrs, u8 *image, case BPF_OR: b2 = 0x09; break; case BPF_XOR: b2 = 0x31; break; } - if (BPF_CLASS(insn->code) == BPF_ALU64) - EMIT1(add_2mod(0x48, dst_reg, src_reg)); - else if (is_ereg(dst_reg) || is_ereg(src_reg)) - EMIT1(add_2mod(0x40, dst_reg, src_reg)); + maybe_emit_mod(&prog, dst_reg, src_reg, + BPF_CLASS(insn->code) == BPF_ALU64); EMIT2(b2, add_2reg(0xC0, dst_reg, src_reg)); break; @@ -1302,20 +1315,16 @@ st: if (is_imm8(insn->off)) case BPF_JMP32 | BPF_JSGE | BPF_X: case BPF_JMP32 | BPF_JSLE | BPF_X: /* cmp dst_reg, src_reg */ - if (BPF_CLASS(insn->code) == BPF_JMP) - EMIT1(add_2mod(0x48, dst_reg, src_reg)); - else if (is_ereg(dst_reg) || is_ereg(src_reg)) - EMIT1(add_2mod(0x40, dst_reg, src_reg)); + maybe_emit_mod(&prog, dst_reg, src_reg, + BPF_CLASS(insn->code) == BPF_JMP); EMIT2(0x39, add_2reg(0xC0, dst_reg, src_reg)); goto emit_cond_jmp; case BPF_JMP | BPF_JSET | BPF_X: case BPF_JMP32 | BPF_JSET | BPF_X: /* test dst_reg, src_reg */ - if (BPF_CLASS(insn->code) == BPF_JMP) - EMIT1(add_2mod(0x48, dst_reg, src_reg)); - else if (is_ereg(dst_reg) || is_ereg(src_reg)) - EMIT1(add_2mod(0x40, dst_reg, src_reg)); + maybe_emit_mod(&prog, dst_reg, src_reg, + BPF_CLASS(insn->code) == BPF_JMP); EMIT2(0x85, add_2reg(0xC0, dst_reg, src_reg)); goto emit_cond_jmp; @@ -1351,10 +1360,8 @@ st: if (is_imm8(insn->off)) case BPF_JMP32 | BPF_JSLE | BPF_K: /* test dst_reg, dst_reg to save one extra byte */ if (imm32 == 0) { - if (BPF_CLASS(insn->code) == BPF_JMP) - EMIT1(add_2mod(0x48, dst_reg, dst_reg)); - else if (is_ereg(dst_reg)) - EMIT1(add_2mod(0x40, dst_reg, dst_reg)); + maybe_emit_mod(&prog, dst_reg, dst_reg, + BPF_CLASS(insn->code) == BPF_JMP); EMIT2(0x85, add_2reg(0xC0, dst_reg, dst_reg)); goto emit_cond_jmp; } -- 2.30.0.284.gd98b1dd5eaa7-goog