From patchwork Mon Dec 7 16:07:31 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Brendan Jackman X-Patchwork-Id: 11956297 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=-26.2 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, URIBL_BLOCKED,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 14F11C4361B for ; Mon, 7 Dec 2020 16:16:48 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D1AEF2376F for ; Mon, 7 Dec 2020 16:16:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726494AbgLGQQ1 (ORCPT ); Mon, 7 Dec 2020 11:16:27 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56836 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726485AbgLGQQ1 (ORCPT ); Mon, 7 Dec 2020 11:16:27 -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 A4319C061749 for ; Mon, 7 Dec 2020 08:15:46 -0800 (PST) Received: by mail-wr1-x44a.google.com with SMTP id r11so3079616wrs.23 for ; Mon, 07 Dec 2020 08:15:46 -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=zKhPLuQByBWIZw1uYTkwBeWZCWJCpLKTPppsP1+IhXE=; b=ZTpFsZawTsqrTEhsVv6t+Xqhsz76zbNDKpourLTywyfZrA+bWEhWDAl0911tNvZZHw l6/Arau5+HTyRJG+IqDJDhx3gqNqcQRffwrp2glc4TbVOr8lk2/uOA9FyfY81rb3mSbP UQr0wmYQM95kB34h4NaJhaLyioUCzmL9a5e2Zeso0x/pObQB+eQbGMluMY/Kw5lOR9wg pIewJKsuDxu4r5HpPWeLGpeH/8UCUH6Lws1tawzxZipSyvITa+0iCrHPVNBHbFx4zFtm dOPc4NAoBZVuiXe/2azfkr0hHkgl4h3Vxnp4MvSjNRv2xzpszRmlLnwuiyGxzn7RFVWA qomA== 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=zKhPLuQByBWIZw1uYTkwBeWZCWJCpLKTPppsP1+IhXE=; b=RRkkRqBWjSsj1LY4jY9aQK7gxvhopv2VpvQR6Qi0sZ5iOT38D8PWFZ3iPcCS5v9uiA h55C399HNEoPzqHGo3G9Q5O/2HLqrT3K7sQsXL7A7lS1fqQhej+AuYNn2Z0MSaWlIAyu OS2Y4icFvMtI6R5m9ZA+cM3XwO0VE7o2xu+ni0TgZseeSskBArXVB/FKwG9Ch9b7VxTW 6uK93w0VtCv6V30tQMmpcau9mWjVsK43C0ZsYOYN35xCHpFWBOf/WgRUH3x1NRMUxQOk hCjruDwuU++BT8ARHGRdT3rix3/hkfwNRDZ1dT4Pnomem0eBGQdqsgejarzSAY06YB4L Fr1g== X-Gm-Message-State: AOAM532rSSjgOIgYuDs28WoDOewhHTGY5lXEX86w6pV/lgzuPaQlgZ2u 8Y9pR/V3Bhuos+8h0DlLprY9F/fKpsSZ/Z2n7KEYEiSgRDT7vOCIObqDeklvMSRmOu5BNPAhSCk ZS7DHi1vmr6emRkTmzUZJQVQxnD72gR8+/UtxoYOP1IPTEuemOrFjioTgsyz0cVU= X-Google-Smtp-Source: ABdhPJzPFZTgMmWGu1YCSsxY0YVICXeUcTVncl9Zvb2JOefQlybNeEyykZOozKpIuJZkK+Oa8rGufwMtCB8FBQ== 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:e084:: with SMTP id x126mr19124582wmg.109.1607357309765; Mon, 07 Dec 2020 08:08:29 -0800 (PST) Date: Mon, 7 Dec 2020 16:07:31 +0000 In-Reply-To: <20201207160734.2345502-1-jackmanb@google.com> Message-Id: <20201207160734.2345502-9-jackmanb@google.com> Mime-Version: 1.0 References: <20201207160734.2345502-1-jackmanb@google.com> X-Mailer: git-send-email 2.29.2.576.ga3fc446d84-goog Subject: [PATCH bpf-next v4 08/11] bpf: Pull out a macro for interpreting atomic ALU operations 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 Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org X-Patchwork-Delegate: bpf@iogearbox.net Since the atomic operations that are added in subsequent commits are all isomorphic with BPF_ADD, pull out a macro to avoid the interpreter becoming dominated by lines of atomic-related code. Note that this sacrificies interpreter performance (combining STX_ATOMIC_W and STX_ATOMIC_DW into single switch case means that we need an extra conditional branch to differentiate them) in favour of compact and (relatively!) simple C code. Acked-by: Yonghong Song Signed-off-by: Brendan Jackman --- kernel/bpf/core.c | 80 +++++++++++++++++++++++------------------------ 1 file changed, 39 insertions(+), 41 deletions(-) diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c index 28f960bc2e30..1d9e5dcde03a 100644 --- a/kernel/bpf/core.c +++ b/kernel/bpf/core.c @@ -1618,55 +1618,53 @@ static u64 ___bpf_prog_run(u64 *regs, const struct bpf_insn *insn, u64 *stack) LDX_PROBE(DW, 8) #undef LDX_PROBE - STX_ATOMIC_W: - switch (IMM) { - case BPF_ADD: - /* lock xadd *(u32 *)(dst_reg + off16) += src_reg */ - atomic_add((u32) SRC, (atomic_t *)(unsigned long) - (DST + insn->off)); - break; - case BPF_ADD | BPF_FETCH: - SRC = (u32) atomic_fetch_add( - (u32) SRC, - (atomic_t *)(unsigned long) (DST + insn->off)); - break; - case BPF_XCHG: - SRC = (u32) atomic_xchg( - (atomic_t *)(unsigned long) (DST + insn->off), - (u32) SRC); - break; - case BPF_CMPXCHG: - BPF_R0 = (u32) atomic_cmpxchg( - (atomic_t *)(unsigned long) (DST + insn->off), - (u32) BPF_R0, (u32) SRC); +#define ATOMIC_ALU_OP(BOP, KOP) \ + case BOP: \ + if (BPF_SIZE(insn->code) == BPF_W) \ + atomic_##KOP((u32) SRC, (atomic_t *)(unsigned long) \ + (DST + insn->off)); \ + else \ + atomic64_##KOP((u64) SRC, (atomic64_t *)(unsigned long) \ + (DST + insn->off)); \ + break; \ + case BOP | BPF_FETCH: \ + if (BPF_SIZE(insn->code) == BPF_W) \ + SRC = (u32) atomic_fetch_##KOP( \ + (u32) SRC, \ + (atomic_t *)(unsigned long) (DST + insn->off)); \ + else \ + SRC = (u64) atomic64_fetch_##KOP( \ + (u64) SRC, \ + (atomic64_t *)(s64) (DST + insn->off)); \ break; - default: - goto default_label; - } - CONT; STX_ATOMIC_DW: + STX_ATOMIC_W: switch (IMM) { - case BPF_ADD: - /* lock xadd *(u64 *)(dst_reg + off16) += src_reg */ - atomic64_add((u64) SRC, (atomic64_t *)(unsigned long) - (DST + insn->off)); - break; - case BPF_ADD | BPF_FETCH: - SRC = (u64) atomic64_fetch_add( - (u64) SRC, - (atomic64_t *)(s64) (DST + insn->off)); - break; + ATOMIC_ALU_OP(BPF_ADD, add) +#undef ATOMIC_ALU_OP + case BPF_XCHG: - SRC = (u64) atomic64_xchg( - (atomic64_t *)(u64) (DST + insn->off), - (u64) SRC); + if (BPF_SIZE(insn->code) == BPF_W) + SRC = (u32) atomic_xchg( + (atomic_t *)(unsigned long) (DST + insn->off), + (u32) SRC); + else + SRC = (u64) atomic64_xchg( + (atomic64_t *)(u64) (DST + insn->off), + (u64) SRC); break; case BPF_CMPXCHG: - BPF_R0 = (u64) atomic64_cmpxchg( - (atomic64_t *)(u64) (DST + insn->off), - (u64) BPF_R0, (u64) SRC); + if (BPF_SIZE(insn->code) == BPF_W) + BPF_R0 = (u32) atomic_cmpxchg( + (atomic_t *)(unsigned long) (DST + insn->off), + (u32) BPF_R0, (u32) SRC); + else + BPF_R0 = (u64) atomic64_cmpxchg( + (atomic64_t *)(u64) (DST + insn->off), + (u64) BPF_R0, (u64) SRC); break; + default: goto default_label; }