From patchwork Mon Mar 15 18:02:25 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kees Cook X-Patchwork-Id: 12140321 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=-19.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, 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 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 A7921C433DB for ; Mon, 15 Mar 2021 18:03:17 +0000 (UTC) Received: from mother.openwall.net (mother.openwall.net [195.42.179.200]) by mail.kernel.org (Postfix) with SMTP id B78F764E81 for ; Mon, 15 Mar 2021 18:03:16 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org B78F764E81 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=chromium.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=kernel-hardening-return-20937-kernel-hardening=archiver.kernel.org@lists.openwall.com Received: (qmail 11448 invoked by uid 550); 15 Mar 2021 18:02:50 -0000 Mailing-List: contact kernel-hardening-help@lists.openwall.com; run by ezmlm Precedence: bulk List-Post: List-Help: List-Unsubscribe: List-Subscribe: List-ID: Received: (qmail 10217 invoked from network); 15 Mar 2021 18:02:48 -0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=K0uLi49Yx6Hs1kogqwqRCUz/Bpqh/dFOqLS4VRKyyBc=; b=NpVfbBSkCMGMjvqUBvpnwYBUDLSg0t4mYOsEdbBvi2yZSriP+lLClj248lVLlV1mpf nX/stjeHOgx3unJ6YY/jz4OctbXPuxLlEunQgCM/jxtNPHvbwL+KbU7nEMw6u8yj22PF /M7fJIqZgumlNjIVXD5qiAhMakD1OX3Kq+TYw= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=K0uLi49Yx6Hs1kogqwqRCUz/Bpqh/dFOqLS4VRKyyBc=; b=pIxpJ/7gcOZ/zRo3JjIxdxDKnBgm3Htz98Doj7V/jT3xS9KgayTJ/z8HTV6ErNQOpS GJGC7tTL8hPxPut/6FKAQlXO0Aj0Qsy6FkiO0bu/RjIclFeZDKVrLAW1r8Afxwvl6O6d EpBxeNSD81pC6jjtBrYxmR0sfOmExKHWhBkWqG84fwqEwxkuWV5FADUnrg+iGZZvWu7s AaCau0bwRxXO7dPGviwvKRP0vm0MM+oRLsvg80Fh+oSnqaY5tgJe7zTaoM1UK9kny8Kk xEdaIw6S1dgRqVV2jtuZl7/g6YZQnO4xCgdxiYzo5GR22GuYNTmqUJ0665Zz2UBIAaNp 5klA== X-Gm-Message-State: AOAM530IJCgCkTdRUFtTrWLXufKjOGekxZEYFxbG3iD5RaOtKZIV9wV9 598rTz/Hmiq3HwWoXxy2muop7w== X-Google-Smtp-Source: ABdhPJw3XuSiNT39U8lLpLBLKNJyfyNfidC2LZuwiQfSz+u6PVqNYpahOsQIoKSVW+ozDdUAE8Umjg== X-Received: by 2002:a17:90b:691:: with SMTP id m17mr276901pjz.191.1615831356378; Mon, 15 Mar 2021 11:02:36 -0700 (PDT) From: Kees Cook To: Thomas Gleixner Cc: Kees Cook , Alexander Potapenko , Elena Reshetova , x86@kernel.org, Andy Lutomirski , Peter Zijlstra , Catalin Marinas , Will Deacon , Mark Rutland , Alexander Popov , Ard Biesheuvel , Jann Horn , Vlastimil Babka , David Hildenbrand , Mike Rapoport , Andrew Morton , Jonathan Corbet , Randy Dunlap , kernel-hardening@lists.openwall.com, linux-hardening@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: [PATCH v6 2/6] init_on_alloc: Optimize static branches Date: Mon, 15 Mar 2021 11:02:25 -0700 Message-Id: <20210315180229.1224655-3-keescook@chromium.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20210315180229.1224655-1-keescook@chromium.org> References: <20210315180229.1224655-1-keescook@chromium.org> MIME-Version: 1.0 X-Patch-Hashes: v=1; h=sha256; g=d73e14f50f59a92ac8538519f3e1f53d503ab26d; i=7VrM8Pzr5MGi8vAaDOW4xeiDtVYbjHgJsdLlT/sxDXE=; m=9pRPoTwktIPBeIWxjZ3xtu7JAekgWFD5JAmIfxnzZpU=; p=kGv6Q+SMrU5E1IdQ/vRaEbpDt4x68fXZGP3gRBxoslM= X-Patch-Sig: m=pgp; i=keescook@chromium.org; s=0x0x8972F4DFDC6DC026; b=iQIzBAABCgAdFiEEpcP2jyKd1g9yPm4TiXL039xtwCYFAmBPoTQACgkQiXL039xtwCYmkw//V/q 8YDIGvlrMf++Qpx3Y4F3jp6BV9YPPaIeh+7wAqmOGLpfhHGIggCuroF6Bx+Pb+rJbjJa63cbQizhi k+AxuhTsUnZpfHDR4Q1TIjsYJAN8XBXR1HGAaLwnq/D20E+EJsPOMDCisEsVPuvQbJdxaW7qb0oDK vmDWKOZCcN7VIYqpXnqB897l8P5RcLTtv4l3yUs1mVosqpb+CNXMSPI1Csr3e8nrZPM5SuoYZakj2 i3gfACSgTGgzqo5KZvY58pagDyHUK7lufPiP9kwsnmq6Jv8OvlbkNQwwC8vzmek5lJ9rpju01wlDr O4a7cCdjmm2CjDMAI1maK25DDY0MkNzViwrAtSJ0g28yVrPq8OTQINu4J/oKsu8DOeU8dk+34adFn 5fSkkgS3r20gMPIrsVPDewIJBmOzWQAUbaFhoUucmBcOAHLPnmmTyOzcBqBgksXuOckNOZcwIUvys Mtb04OUCS3Pxzl1b3XcOLInfxgqm88Bre7PgJv5HvexCmdLHKJ6aCNojW9UP4qngdA/HgFkL0LTwU PwcmH+LmUx5Ofpm8QT/VEoUhjsA3j9ZHX/R7vfwe9w6Sl42G6IXNZr9Ft79uOnYTfh3rkH8ksvs/U Xmq1KzeG9cpSvVSK3U4JH8tziH45YgiOwYUOazJKUTgYCIyV6QPse1xpMvnH/cXs= The state of CONFIG_INIT_ON_ALLOC_DEFAULT_ON (and ...ON_FREE...) did not change the assembly ordering of the static branches: they were always out of line. Use the new jump_label macros to check the CONFIG settings to default to the "expected" state, which slightly optimizes the resulting assembly code. Reviewed-by: Alexander Potapenko Link: https://lore.kernel.org/lkml/CAG_fn=X0DVwqLaHJTO6Jw7TGcMSm77GKHinrd0m_6y0SzWOrFA@mail.gmail.com/ Signed-off-by: Kees Cook Acked-by: Vlastimil Babka --- include/linux/mm.h | 10 ++++++---- mm/page_alloc.c | 4 ++-- mm/slab.h | 6 ++++-- 3 files changed, 12 insertions(+), 8 deletions(-) diff --git a/include/linux/mm.h b/include/linux/mm.h index 77e64e3eac80..2ccd856ac0d1 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -2871,18 +2871,20 @@ static inline void kernel_poison_pages(struct page *page, int numpages) { } static inline void kernel_unpoison_pages(struct page *page, int numpages) { } #endif -DECLARE_STATIC_KEY_FALSE(init_on_alloc); +DECLARE_STATIC_KEY_MAYBE(CONFIG_INIT_ON_ALLOC_DEFAULT_ON, init_on_alloc); static inline bool want_init_on_alloc(gfp_t flags) { - if (static_branch_unlikely(&init_on_alloc)) + if (static_branch_maybe(CONFIG_INIT_ON_ALLOC_DEFAULT_ON, + &init_on_alloc)) return true; return flags & __GFP_ZERO; } -DECLARE_STATIC_KEY_FALSE(init_on_free); +DECLARE_STATIC_KEY_MAYBE(CONFIG_INIT_ON_FREE_DEFAULT_ON, init_on_free); static inline bool want_init_on_free(void) { - return static_branch_unlikely(&init_on_free); + return static_branch_maybe(CONFIG_INIT_ON_FREE_DEFAULT_ON, + &init_on_free); } extern bool _debug_pagealloc_enabled_early; diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 3e4b29ee2b1e..267c04b8911d 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -167,10 +167,10 @@ unsigned long totalcma_pages __read_mostly; int percpu_pagelist_fraction; gfp_t gfp_allowed_mask __read_mostly = GFP_BOOT_MASK; -DEFINE_STATIC_KEY_FALSE(init_on_alloc); +DEFINE_STATIC_KEY_MAYBE(CONFIG_INIT_ON_ALLOC_DEFAULT_ON, init_on_alloc); EXPORT_SYMBOL(init_on_alloc); -DEFINE_STATIC_KEY_FALSE(init_on_free); +DEFINE_STATIC_KEY_MAYBE(CONFIG_INIT_ON_FREE_DEFAULT_ON, init_on_free); EXPORT_SYMBOL(init_on_free); static bool _init_on_alloc_enabled_early __read_mostly diff --git a/mm/slab.h b/mm/slab.h index 076582f58f68..b0977d525c06 100644 --- a/mm/slab.h +++ b/mm/slab.h @@ -601,7 +601,8 @@ static inline void cache_random_seq_destroy(struct kmem_cache *cachep) { } static inline bool slab_want_init_on_alloc(gfp_t flags, struct kmem_cache *c) { - if (static_branch_unlikely(&init_on_alloc)) { + if (static_branch_maybe(CONFIG_INIT_ON_FREE_DEFAULT_ON, + &init_on_alloc)) { if (c->ctor) return false; if (c->flags & (SLAB_TYPESAFE_BY_RCU | SLAB_POISON)) @@ -613,7 +614,8 @@ static inline bool slab_want_init_on_alloc(gfp_t flags, struct kmem_cache *c) static inline bool slab_want_init_on_free(struct kmem_cache *c) { - if (static_branch_unlikely(&init_on_free)) + if (static_branch_maybe(CONFIG_INIT_ON_FREE_DEFAULT_ON, + &init_on_free)) return !(c->ctor || (c->flags & (SLAB_TYPESAFE_BY_RCU | SLAB_POISON))); return false;