From patchwork Fri Nov 27 17:57:34 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Brendan Jackman X-Patchwork-Id: 11937021 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=-26.3 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 3F7F3C83010 for ; Fri, 27 Nov 2020 17:58:25 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0D41A2224C for ; Fri, 27 Nov 2020 17:58:25 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="ODBuhzIh" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732966AbgK0R6K (ORCPT ); Fri, 27 Nov 2020 12:58:10 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37790 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1732965AbgK0R6K (ORCPT ); Fri, 27 Nov 2020 12:58:10 -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 A9D75C0613D2 for ; Fri, 27 Nov 2020 09:58:08 -0800 (PST) Received: by mail-wr1-x449.google.com with SMTP id p16so3781569wrx.4 for ; Fri, 27 Nov 2020 09:58:08 -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=l/XmS3F8heDnnCjC/QfV3ASRMXtsU72vcNxRpP0pgcs=; b=ODBuhzIhRy9z+TV6wyH1yjSarGBb4XmnN5EPraWYd1vPji65yN00rSZc4BOORsN10F KUeBOIxRFoEbm8drjKMMs5bkgePqf3zFtQv0HrzoEvdjVaJ+PRbyrBBzUndMp3jqgRzf zIy1HHpUp3V7nyA/AEHmMjl8CN2le2PY8sbBAGa0fG0FOCSjsluVQbFQ9v0xBJ/96eyn qag9Th0QAqHNfKM2mQYxNCpc5Kffi9lTsde/4HpofgU9ifatDDSECJrZ8Qcg5u2jJnWW DAOCt0MQ+Kbm4Jty+GHSBLfYNxgGV0ljuF31KDPbped5l0U5plfpzcayOhUo1dq0oS4C fwnw== 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=l/XmS3F8heDnnCjC/QfV3ASRMXtsU72vcNxRpP0pgcs=; b=J146vua/I8mKnEOQoqi7PshVZ/xEzHVtGS/AWvNlUNlYSgSzvYCErq3DA2RpNTE/HC lUGlgdF+kVMGWvb+sueRwkkTQblyf3YvCMDGl0dYOUQNLWKt2K+s3pc85Iad7Fmx8kpc wWGdCbsXUs+dhPIylQUWgUeRDQQtg/jpAoZQwcIbJgjLMcG4ILErex1JUd1dcZTEPxAY q3rSyWnbXTvHUb1Fxh/vZq1+gL2/iuJXMWVorpCTwCxw1aYgvBHDmGV5BovpRgqBXYWb f2rI+8/2Pe9mn1MB1xnQTP2lHxQRAJRczVAa9ZH2YkGVHHAG2S/V1zy8b/2hYpukY6Nl IPSg== X-Gm-Message-State: AOAM530zecVjuAAIA0WPRwiWQSXX1G/PLgoXP8I/pI7n6AnxLKAwWKLL tQS5k+pyzxqHAyNO9LpT7Y3rGB9CdgO2HTdhwPxNihw/RlJMMCuiegZrRiwaHUWF2lxyTar3r7O VBqPliaxmTyIe3MaU74l61fgWFD6BR3REPFvmInVava5e8/ETc1H2teYN9otST0c= X-Google-Smtp-Source: ABdhPJxrqimB5kfC4aGvATRJWvBfKmL+97XEjnMgu/Khl1atRW6kZO7Yyo7TGLngWUlU2fos3PI8GDhHlYsr/A== 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:e787:: with SMTP id n7mr12379892wrm.153.1606499887359; Fri, 27 Nov 2020 09:58:07 -0800 (PST) Date: Fri, 27 Nov 2020 17:57:34 +0000 In-Reply-To: <20201127175738.1085417-1-jackmanb@google.com> Message-Id: <20201127175738.1085417-10-jackmanb@google.com> Mime-Version: 1.0 References: <20201127175738.1085417-1-jackmanb@google.com> X-Mailer: git-send-email 2.29.2.454.gaff20da3a2-goog Subject: [PATCH v2 bpf-next 09/13] 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. Signed-off-by: Brendan Jackman --- kernel/bpf/core.c | 79 +++++++++++++++++++++++------------------------ 1 file changed, 38 insertions(+), 41 deletions(-) diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c index 05350a8f87c0..20a5351d1dc2 100644 --- a/kernel/bpf/core.c +++ b/kernel/bpf/core.c @@ -1626,55 +1626,52 @@ 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(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(BPF_ADD, add) + 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; }