From patchwork Tue Mar 24 20:32:27 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kees Cook X-Patchwork-Id: 11456465 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 15B05913 for ; Tue, 24 Mar 2020 20:33:28 +0000 (UTC) Received: from mother.openwall.net (mother.openwall.net [195.42.179.200]) by mail.kernel.org (Postfix) with SMTP id 4947420735 for ; Tue, 24 Mar 2020 20:33:27 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=chromium.org header.i=@chromium.org header.b="BcF5fu0w" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 4947420735 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-18198-patchwork-kernel-hardening=patchwork.kernel.org@lists.openwall.com Received: (qmail 18048 invoked by uid 550); 24 Mar 2020 20:32:55 -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: Delivered-To: mailing list kernel-hardening@lists.openwall.com Received: (qmail 17835 invoked from network); 24 Mar 2020 20:32:53 -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=1MVGnSojuGRbIf385C9jQfbyEyUVxBYpFXB8EsCcrYw=; b=BcF5fu0w+3RjSRBoJOMuJwRkQ7K/mRa1BZHJeNserbqzlapS73yhJkI9BAFD3QlZia /tK6Q6a0Xix0108WsK916BMXctBv6x/nqlbYs0Fqc2Fl/c07lkSHe4EI2UglGuLZrWzk OsxF7OZPK7kzoWTSxKgurb1BP56sAT/bnrrp0= 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=1MVGnSojuGRbIf385C9jQfbyEyUVxBYpFXB8EsCcrYw=; b=rBRz6xQsAYtVOMoy+YMmiTrrUAKv+BzkR6B6tvidDn0YdoMzjqnPLd9Z9SSOn8nvJt RLNMX0+I9T0mPlU8nm5k9IFS+3NpMBYCfMbuG9CsLX3RA0RDvSKDdsyHzOkPqEBXvMa2 UtcUzEdqmWpPVw/ZwaKyIMHW9lafGvxV5kfG2Dr8Mcd1s/oYUoLNSRgTFgtk4nsrZIuH rprHlCNCzuttbwmMdI4sBmFyDdeLlkpmXxyZzsxouig952n4zcqltVLN5Q0QAcx45fmi 0aEdHgBQ8E9vQxJHoseQ3tcwrBRe1U+IzKJEP71miufDcQif3Z/ui7sR5luvHjXic9v1 +BoQ== X-Gm-Message-State: ANhLgQ1i7pmYotT11cjMWObt93qhGT5Wd4A/xVZhWwl74EXqFPITGXNx 3j5VNuEZJSwPLnVjWcQduOr2HQ== X-Google-Smtp-Source: ADFU+vvnVRb00GhJN60Odz51h8y0qLnFMPgufkKkVflkAhmJwmU/2do8qdmBufOmVDll0iyTu12GSw== X-Received: by 2002:a17:902:61:: with SMTP id 88mr28126394pla.313.1585081961408; Tue, 24 Mar 2020 13:32:41 -0700 (PDT) From: Kees Cook To: Thomas Gleixner Cc: Kees Cook , Elena Reshetova , x86@kernel.org, Andy Lutomirski , Peter Zijlstra , Catalin Marinas , Will Deacon , Mark Rutland , Alexander Potapenko , Ard Biesheuvel , Jann Horn , "Perla, Enrico" , kernel-hardening@lists.openwall.com, linux-arm-kernel@lists.infradead.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: [PATCH v2 1/5] jump_label: Provide CONFIG-driven build state defaults Date: Tue, 24 Mar 2020 13:32:27 -0700 Message-Id: <20200324203231.64324-2-keescook@chromium.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20200324203231.64324-1-keescook@chromium.org> References: <20200324203231.64324-1-keescook@chromium.org> MIME-Version: 1.0 Choosing the initial state of static branches changes the assembly layout (if the condition is expected to be likely, inline, or unlikely, out of line via a jump). A few places in the kernel use (or could be using) a CONFIG to choose the default state, so provide the infrastructure to do this and convert the existing cases (init_on_alloc and init_on_free) to the new macros. Signed-off-by: Kees Cook Acked-by: Peter Zijlstra (Intel) --- include/linux/jump_label.h | 19 +++++++++++++++++++ include/linux/mm.h | 12 ++---------- mm/page_alloc.c | 12 ++---------- 3 files changed, 23 insertions(+), 20 deletions(-) diff --git a/include/linux/jump_label.h b/include/linux/jump_label.h index 3526c0aee954..615fdfb871a3 100644 --- a/include/linux/jump_label.h +++ b/include/linux/jump_label.h @@ -382,6 +382,21 @@ struct static_key_false { [0 ... (count) - 1] = STATIC_KEY_FALSE_INIT, \ } +#define _DEFINE_STATIC_KEY_1(name) DEFINE_STATIC_KEY_TRUE(name) +#define _DEFINE_STATIC_KEY_0(name) DEFINE_STATIC_KEY_FALSE(name) +#define DEFINE_STATIC_KEY_MAYBE(cfg, name) \ + __PASTE(_DEFINE_STATIC_KEY_, IS_ENABLED(cfg))(name) + +#define _DEFINE_STATIC_KEY_RO_1(name) DEFINE_STATIC_KEY_TRUE_RO(name) +#define _DEFINE_STATIC_KEY_RO_0(name) DEFINE_STATIC_KEY_FALSE_RO(name) +#define DEFINE_STATIC_KEY_MAYBE_RO(cfg, name) \ + __PASTE(_DEFINE_STATIC_KEY_RO_, IS_ENABLED(cfg))(name) + +#define _DECLARE_STATIC_KEY_1(name) DECLARE_STATIC_KEY_TRUE(name) +#define _DECLARE_STATIC_KEY_0(name) DECLARE_STATIC_KEY_FALSE(name) +#define DECLARE_STATIC_KEY_MAYBE(cfg, name) \ + __PASTE(_DECLARE_STATIC_KEY_, IS_ENABLED(cfg))(name) + extern bool ____wrong_branch_error(void); #define static_key_enabled(x) \ @@ -482,6 +497,10 @@ extern bool ____wrong_branch_error(void); #endif /* CONFIG_JUMP_LABEL */ +#define static_branch_maybe(config, x) \ + (IS_ENABLED(config) ? static_branch_likely(x) \ + : static_branch_unlikely(x)) + /* * Advanced usage; refcount, branch is enabled when: count != 0 */ diff --git a/include/linux/mm.h b/include/linux/mm.h index c54fb96cb1e6..059658604dd6 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -2662,11 +2662,7 @@ static inline void kernel_poison_pages(struct page *page, int numpages, int enable) { } #endif -#ifdef CONFIG_INIT_ON_ALLOC_DEFAULT_ON -DECLARE_STATIC_KEY_TRUE(init_on_alloc); -#else -DECLARE_STATIC_KEY_FALSE(init_on_alloc); -#endif +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) && @@ -2675,11 +2671,7 @@ static inline bool want_init_on_alloc(gfp_t flags) return flags & __GFP_ZERO; } -#ifdef CONFIG_INIT_ON_FREE_DEFAULT_ON -DECLARE_STATIC_KEY_TRUE(init_on_free); -#else -DECLARE_STATIC_KEY_FALSE(init_on_free); -#endif +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) && diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 3c4eb750a199..1f625e5a03c0 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -135,18 +135,10 @@ unsigned long totalcma_pages __read_mostly; int percpu_pagelist_fraction; gfp_t gfp_allowed_mask __read_mostly = GFP_BOOT_MASK; -#ifdef CONFIG_INIT_ON_ALLOC_DEFAULT_ON -DEFINE_STATIC_KEY_TRUE(init_on_alloc); -#else -DEFINE_STATIC_KEY_FALSE(init_on_alloc); -#endif +DEFINE_STATIC_KEY_MAYBE(CONFIG_INIT_ON_ALLOC_DEFAULT_ON, init_on_alloc); EXPORT_SYMBOL(init_on_alloc); -#ifdef CONFIG_INIT_ON_FREE_DEFAULT_ON -DEFINE_STATIC_KEY_TRUE(init_on_free); -#else -DEFINE_STATIC_KEY_FALSE(init_on_free); -#endif +DEFINE_STATIC_KEY_MAYBE(CONFIG_INIT_ON_FREE_DEFAULT_ON, init_on_free); EXPORT_SYMBOL(init_on_free); static int __init early_init_on_alloc(char *buf)