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=-18.8 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, URIBL_BLOCKED,USER_AGENT_GIT 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 0B812C433E5 for ; Tue, 30 Mar 2021 20:58:35 +0000 (UTC) Received: from mother.openwall.net (mother.openwall.net [195.42.179.200]) by mail.kernel.org (Postfix) with SMTP id 2878A6199A for ; Tue, 30 Mar 2021 20:58:33 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 2878A6199A 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-21086-kernel-hardening=archiver.kernel.org@lists.openwall.com Received: (qmail 5273 invoked by uid 550); 30 Mar 2021 20:58:08 -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 5154 invoked from network); 30 Mar 2021 20:58:06 -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=UG6lpZSAG8t+NfdJici9YkMGF34rxaYTMGPEmVDXXFs=; b=nAtL0yLEpjO2guyFAnk1UK8RCNVE817hSH2Q172t9upN0Y9DcHi4VPdazL0wXZjLfd xlHHSMBZWyFEw7jxyLinGl0JaLbvCqzWK4kVm5P+6y5xzoKJRTbfmuOnH8+1yQshwVQ8 emm1ECwHM5YtpWRAoVYZwoNNTFLms6VvWOqLU= 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=UG6lpZSAG8t+NfdJici9YkMGF34rxaYTMGPEmVDXXFs=; b=CZ5b/Wuc391ZgPusxnKyuEL3mXTjqdCqHjyAqPncjdjO8pWnlSS0RuaxhOZMY3qTlg h3RK9TOH86XeFKZhj0++J+88B5WIQZwiD+HOnHjKP+OksuA7o/QaQhKPl2ceMcnApZ3u +xNeNefq8Y5Ycsu1S6HFiZnYU243W/PgoEjmq8RJyR3qJJv6pu0NdGdZAmh2TOWMjXib Frc+Ia2N0RdwgL6ijwjwX6QNoBJgnUM7pYDKsJ95N0+aBlavPWI8aWhuGJEN1oldXhfS 6D5HN/2X5/iC4se0pQEwaCR7XsuaPMRhFqwFlaygkMnt56Gw38w2G6Zq8b0NoAqklZwC WMbA== X-Gm-Message-State: AOAM531IIJfmXgPukcnCietGBzRypl7ECO9JYbD1Z7TkovDGduRhIzwQ wZDrON1Su//o/SYESBuuRpLzoQ== X-Google-Smtp-Source: ABdhPJz3LXv4eDOhFhF6lIjzHku5IEzcEABiR69AQC5cXMNAv6qJ/s1o3KIyukaQCofHm60NmmHgeA== X-Received: by 2002:a62:8fcd:0:b029:218:461:2279 with SMTP id n196-20020a628fcd0000b029021804612279mr31460592pfd.43.1617137873522; Tue, 30 Mar 2021 13:57:53 -0700 (PDT) From: Kees Cook To: Thomas Gleixner Cc: Kees Cook , Alexander Potapenko , Vlastimil Babka , Elena Reshetova , x86@kernel.org, Andy Lutomirski , Peter Zijlstra , Catalin Marinas , Will Deacon , Mark Rutland , Alexander Popov , Ard Biesheuvel , Jann Horn , 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 v8 2/6] init_on_alloc: Optimize static branches Date: Tue, 30 Mar 2021 13:57:46 -0700 Message-Id: <20210330205750.428816-3-keescook@chromium.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20210330205750.428816-1-keescook@chromium.org> References: <20210330205750.428816-1-keescook@chromium.org> MIME-Version: 1.0 X-Patch-Hashes: v=1; h=sha256; g=2f4b59272e09d0180c87e3d8378d95ea375990ec; i=7VrM8Pzr5MGi8vAaDOW4xeiDtVYbjHgJsdLlT/sxDXE=; m=OLLKLAHsfNT1d7+pflxMGJuAvSt8GZaetKIXzfk0ilc=; p=cKq4RSNZSRZ+ASTC07w37jURMQB1hxGsdgqU07adDH0= X-Patch-Sig: m=pgp; i=keescook@chromium.org; s=0x0x8972F4DFDC6DC026; b=iQIzBAABCgAdFiEEpcP2jyKd1g9yPm4TiXL039xtwCYFAmBjkMwACgkQiXL039xtwCZc3RAAneZ W9nsrEVAJu/2EM9W3eP/wNa9JCKIEGXsfdWDWQPPeCbpGDVnJgSVyjiCWUFr4tej6kSR2JcjNkDtk RamMPpNcmIBTAEQZCMJvmrtcKW1IDd/OGeQba5IsPM2+nzcu7TIihfbnaOaO007hiw5q0lN0dy6Vz INq699xnV4EDdLtYeikcR+yHjgF9BrTpVkRdUUD05riIM5MKdp1bCEELMVGvRNofeTRfnTwGW+P08 L8DpSkB+4LmS285BqK0bLDrBFkIlT32vvQmNur8jFep9Yddh2uApO3GfmkatNKXr2pZhthk9ylXAt oLYfDTHsftsgfeBeeCgYWbz52VxjzKw2QlqYy98p2kmLbSWjhZs+mnMvjUfTsHk3tE8pULROEkkxQ EYBq2yGgZCxW/DplktGsnIw2+IuXr5ZVmszBhCU7fjdfnuUpGieeboPgZ3bsyFyLCg5COu0WaMU2k NqhLH42LJzP9w7bvvdccxuPX4DwZjsue4iDmmZgYnWCq20wHcbjVquMuhe5+Z4iMSYCe12rKUT8mh qYDodBX6u5xZgbfJp+x144gtPE89shG9i69yAXKWgC/kRl/en7wYjeg0utnlpYkc+Vg0Oe3I5Jkfs TmEtbMUzu1eA1785dXZn5CS1UZL6KK1W57w5r0f3u7y/IwvVYp1i1NAnZT/lq1BQ= Content-Transfer-Encoding: 8bit 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/ Acked-by: Vlastimil Babka Link: https://lore.kernel.org/lkml/5d626b9b-5355-be94-e8e2-1be47f880f30@suse.cz Signed-off-by: Kees Cook --- 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..774c7221efdc 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_ALLOC_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; -- 2.25.1