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 00D37C43381 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 B21502312F for ; Tue, 12 Jan 2021 15:43:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2403844AbhALPnY (ORCPT ); Tue, 12 Jan 2021 10:43:24 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52774 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2391924AbhALPnX (ORCPT ); Tue, 12 Jan 2021 10:43:23 -0500 Received: from mail-wr1-x44a.google.com (mail-wr1-x44a.google.com [IPv6:2a00:1450:4864:20::44a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 911A5C061794 for ; Tue, 12 Jan 2021 07:42:42 -0800 (PST) Received: by mail-wr1-x44a.google.com with SMTP id v7so1325785wra.3 for ; Tue, 12 Jan 2021 07:42:42 -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=Alxp/7McXhYTRj4ejJtb24GbL7XVg9SRHlt2G3JYcMOF79DupYcmHMkpMBV3rA26lL /t5W3RV9xFJTYTyzog+0/MA14nHuB+2z8uSslCINuDe4F9Z9NDg4EVm+QjsPIAHL+awx cUJBZs88nezRLWlkujK8fNlx1M5fdL+P/0pU4bJujWoHXzl5x0ZEctucjpdRaytc/ULD V8VivzQI/ByniVMebsIDDdapi5QgQx4tAXA2849ljJ4+913FTp0ftUwgjbZPjdDd74Rt ru5FJctTCCOPTy5xiYvXft5ecFFIUouOM2CVWeAeL+erG+cLh62c++oeysHylF9Wj7z3 VQ/w== 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=RR9vVsFCrUmM+oFlaH6HU6Ar/pyFYLBO/6Ea+qoiXnh/VCfc0uGf3ynq9H0GWCLeJ2 w5iVKLMF17ciutD1PeG8DkkwxjQscvH8RmlQN+C73TQ23FyXK2wNncHDeKhnmwMWA3+g 95quoSwSs6GqIyA9EnkHCuZTH+lXiXSa/OMHY29U65X0JCPPdnQWFxfxp8lfCKiU4nru O4R6Y0iVkXyv8TdZmAOyIbI8Qw+f6giNoNltQgh6I+WAZr99uUbJm7Q7c85dPPnD6/so 8WaBFiZ/RMXenGQBcO9lq4O8tz3imd3SXQk4AJuOXnOC+PuO14cMixCU0k4la3zUBVOs 597g== X-Gm-Message-State: AOAM5304dU97ViDcIYCGVaVTPoo/FpsRbOSE4+1e70Q1kcWMWgV37Oim GgItwpFEdNzYpZL1uPN/s2ImqBgqWKzLOA== X-Google-Smtp-Source: ABdhPJy39n98utrSDxBW1caz3c1idclRUV/R3dDPJK/sQu0zHVoQF3090gJOgJ5v2X5g/AMrnVfOWm5chc32Wg== 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:8290:: with SMTP id 16mr4792288wrc.27.1610466161171; Tue, 12 Jan 2021 07:42:41 -0800 (PST) Date: Tue, 12 Jan 2021 15:42:25 +0000 In-Reply-To: <20210112154235.2192781-1-jackmanb@google.com> Message-Id: <20210112154235.2192781-2-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 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