From patchwork Tue Feb 23 02:35:28 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jian Cai X-Patchwork-Id: 12099789 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=-15.7 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_ADSP_CUSTOM_MED,DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,MISSING_HEADERS, 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 50F8CC433E0 for ; Tue, 23 Feb 2021 02:37:04 +0000 (UTC) Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 0701964E3F for ; Tue, 23 Feb 2021 02:37:04 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 0701964E3F Authentication-Results: mail.kernel.org; dmarc=fail (p=reject dis=none) header.from=google.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=merlin.20170209; h=Sender:Content-Transfer-Encoding: Content-Type:Cc:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:From:Subject:References:Mime-Version:Message-Id: In-Reply-To:Date:Reply-To:To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=fFljfvtpHkcJVYs1gtw5tXBviQB1bWWuBxQLc41IaBM=; b=NdcCOUkdKjUSOQxzoDh1NF91G 3iQY4igFWvN2HWvP3Qvwv4X8j/YqwdVIGwrW8M02axTaZKQ5f7E/l9Xr7dRzlFJtRCu5SZ3R+FYcZ 33M93Ojwr+4Qt4FTBk6f3voGryRHlc0IZsGT6Tl8PF/+LZY9RORAvVHumxTt5XAUjhVLhAkKk9Xe7 Lq57UIMk8NDiNTJh9l+VMgnyTx5W3JrRu0tT1s6E6RRuAROpKVG7wT4WApDdaABKUJTSr4WJB2A5M iKFExi8lAa/AIaUjQqfPxSxVJHb9I13ZzCuJYAtw7h72W0favFhMqtreD1YZ2i3X/7Hw7V6uJf96X Q6+8fte+A==; Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1lENYH-0006bn-36; Tue, 23 Feb 2021 02:35:53 +0000 Received: from mail-pl1-x64a.google.com ([2607:f8b0:4864:20::64a]) by merlin.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1lENYE-0006ag-EM for linux-arm-kernel@lists.infradead.org; Tue, 23 Feb 2021 02:35:51 +0000 Received: by mail-pl1-x64a.google.com with SMTP id a6so9339617plm.17 for ; Mon, 22 Feb 2021 18:35:47 -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:cc; bh=PGrLnEq5sje+DbyVyjyk9DtPrIKTxkj/GFVaSNwb+20=; b=lQPJcLW5Zj/rVq/5KMZi6Bk5Gxp9bi/jqYNJj/hkmFM6gzte6FNZy8pUhQPuF48DW5 rgdLyFQsyQ6U4RJUQqukWwxkSjocc0fLx+yt1DM01Qk39F7C/1AXZh+zjBdJxQ/3G0By 9Q1STBNlBg5Q7c+WlQM3qRq5jdlJ/xEHfGwh+b+RySqJGyYgto60gGTcmqgVTnskcTia voGzzLmvFVyrWpAvMnajOE6rcF29MHLzcWao+b+LIqDC6xm2dNFZctXjqUO3V/BvFPkl xIDw2+GeuCSLwm+cSUCmzXDs9pW4C7jufUXw/nbxuMFcESLv2rHy/6q1Bho4udqCsDPz 0t3w== 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:cc; bh=PGrLnEq5sje+DbyVyjyk9DtPrIKTxkj/GFVaSNwb+20=; b=Aseqs7De9HvmxWiJXgnMgPftA3TncAOj4q5O8L526kXzoSoNP013pmNXL4L6K20mG8 vHlbVo8nS2SMvgV03wFaRF7AmAn1gj+XiMWeFXRExT1eFYJp7Mkouhy0EG2+201moJIz +sr2tTpB4AMu1odkSv6u1y1hKEPgFMZJx7VW1ufxhtLw3XV23RxCEtjB6ycr7hfltGo/ YH2iId9v+K9fuU7TLBe0cinDkBUWZQD3U+43MfAAycmvtCo+jVCzbTDcx1RgcP25T7gd VayPlALcQ36H1TzfiFjXEX1k4pRyHHMHnFb8NUzWth265vtyX0BnV1cyXmYbeJzWtGHw lGbg== X-Gm-Message-State: AOAM533as/Uz/K+9O4lNpWH6O+TXHDDH1H1xRPX971C6tx1uJc2vzdyY /Ph8a3lf9n8Rg3yXhmbd7954t1MuJz1q X-Google-Smtp-Source: ABdhPJwpIgoHP79+CAP1cZb8niAgyx2loeUCwl0+OoIAPkr358YzHC0nbYkhT6jM2oeR9Nm6NApKoYyBPvq+ X-Received: from jiancai.svl.corp.google.com ([2620:15c:2ce:0:7985:60cc:661a:9692]) (user=jiancai job=sendgmr) by 2002:a17:90a:8e83:: with SMTP id f3mr27877234pjo.70.1614047746241; Mon, 22 Feb 2021 18:35:46 -0800 (PST) Date: Mon, 22 Feb 2021 18:35:28 -0800 In-Reply-To: <20210223023125.2265845-1-jiancai@google.com> Message-Id: <20210223023542.2287529-1-jiancai@google.com> Mime-Version: 1.0 References: <20210223023125.2265845-1-jiancai@google.com> X-Mailer: git-send-email 2.30.0.617.g56c4b15f3c-goog Subject: [PATCH v5] ARM: Implement SLS mitigation From: Jian Cai X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20210222_213550_551411_E51019E8 X-CRM114-Status: GOOD ( 17.66 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Mark Rutland , Catalin Marinas , James Morris , manojgupta@google.com, Will Deacon , Ingo Molnar , Marc Zyngier , Masahiro Yamada , Russell King , Krzysztof Kozlowski , Ard Biesheuvel , clang-built-linux@googlegroups.com, llozano@google.com, David Brazdil , "Serge E. Hallyn" , Kees Cook , Arnd Bergmann , Jian Cai , Nathan Chancellor , Russell King , linux-arm-kernel@lists.infradead.org, ndesaulniers@google.com, linux-kernel@vger.kernel.org, linux-security-module@vger.kernel.org, David Laight , James Morse , Andrew Morton , =?utf-8?q?Andreas_F=C3=A4rber?= , Mike Rapoport Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org This patch adds CONFIG_HARDEN_SLS_ALL that can be used to turn on -mharden-sls=all, which mitigates the straight-line speculation vulnerability, speculative execution of the instruction following some unconditional jumps. Notice -mharden-sls= has other options as below, and this config turns on the strongest option. all: enable all mitigations against Straight Line Speculation that are implemented. none: disable all mitigations against Straight Line Speculation. retbr: enable the mitigation against Straight Line Speculation for RET and BR instructions. blr: enable the mitigation against Straight Line Speculation for BLR instructions. Links: https://reviews.llvm.org/D93221 https://reviews.llvm.org/D81404 https://developer.arm.com/support/arm-security-updates/speculative-processor-vulnerability/downloads/straight-line-speculation https://developer.arm.com/support/arm-security-updates/speculative-processor-vulnerability/frequently-asked-questions#SLS2 Suggested-by: Manoj Gupta Suggested-by: Nick Desaulniers Suggested-by: Nathan Chancellor Suggested-by: David Laight Suggested-by: Will Deacon Suggested-by: Russell King Reviewed-by: Nathan Chancellor Signed-off-by: Jian Cai --- Changes v4->v5: Removed "default n" and made the description target indepdent in Kconfig.hardening. Please ignore my last email, it did not include the changes. arch/arm/Makefile | 4 ++++ arch/arm/include/asm/vmlinux.lds.h | 4 ++++ arch/arm/kernel/vmlinux.lds.S | 1 + arch/arm64/Makefile | 4 ++++ arch/arm64/kernel/vmlinux.lds.S | 5 +++++ security/Kconfig.hardening | 8 ++++++++ 6 files changed, 26 insertions(+) diff --git a/arch/arm/Makefile b/arch/arm/Makefile index 4aaec9599e8a..11d89ef32da9 100644 --- a/arch/arm/Makefile +++ b/arch/arm/Makefile @@ -48,6 +48,10 @@ CHECKFLAGS += -D__ARMEL__ KBUILD_LDFLAGS += -EL endif +ifeq ($(CONFIG_HARDEN_SLS_ALL), y) +KBUILD_CFLAGS += -mharden-sls=all +endif + # # The Scalar Replacement of Aggregates (SRA) optimization pass in GCC 4.9 and # later may result in code being generated that handles signed short and signed diff --git a/arch/arm/include/asm/vmlinux.lds.h b/arch/arm/include/asm/vmlinux.lds.h index 4a91428c324d..c7f9717511ca 100644 --- a/arch/arm/include/asm/vmlinux.lds.h +++ b/arch/arm/include/asm/vmlinux.lds.h @@ -145,3 +145,7 @@ __edtcm_data = .; \ } \ . = __dtcm_start + SIZEOF(.data_dtcm); + +#define SLS_TEXT \ + ALIGN_FUNCTION(); \ + *(.text.__llvm_slsblr_thunk_*) diff --git a/arch/arm/kernel/vmlinux.lds.S b/arch/arm/kernel/vmlinux.lds.S index f7f4620d59c3..e71f2bc97bae 100644 --- a/arch/arm/kernel/vmlinux.lds.S +++ b/arch/arm/kernel/vmlinux.lds.S @@ -63,6 +63,7 @@ SECTIONS .text : { /* Real text segment */ _stext = .; /* Text and read-only data */ ARM_TEXT + SLS_TEXT } #ifdef CONFIG_DEBUG_ALIGN_RODATA diff --git a/arch/arm64/Makefile b/arch/arm64/Makefile index 90309208bb28..ca7299b356a9 100644 --- a/arch/arm64/Makefile +++ b/arch/arm64/Makefile @@ -34,6 +34,10 @@ $(warning LSE atomics not supported by binutils) endif endif +ifeq ($(CONFIG_HARDEN_SLS_ALL), y) +KBUILD_CFLAGS += -mharden-sls=all +endif + cc_has_k_constraint := $(call try-run,echo \ 'int main(void) { \ asm volatile("and w0, w0, %w0" :: "K" (4294967295)); \ diff --git a/arch/arm64/kernel/vmlinux.lds.S b/arch/arm64/kernel/vmlinux.lds.S index 4c0b0c89ad59..f8912e42ffcd 100644 --- a/arch/arm64/kernel/vmlinux.lds.S +++ b/arch/arm64/kernel/vmlinux.lds.S @@ -93,6 +93,10 @@ jiffies = jiffies_64; #define TRAMP_TEXT #endif +#define SLS_TEXT \ + ALIGN_FUNCTION(); \ + *(.text.__llvm_slsblr_thunk_*) + /* * The size of the PE/COFF section that covers the kernel image, which * runs from _stext to _edata, must be a round multiple of the PE/COFF @@ -144,6 +148,7 @@ SECTIONS HIBERNATE_TEXT TRAMP_TEXT *(.fixup) + SLS_TEXT *(.gnu.warning) . = ALIGN(16); *(.got) /* Global offset table */ diff --git a/security/Kconfig.hardening b/security/Kconfig.hardening index 269967c4fc1b..db76ad732c14 100644 --- a/security/Kconfig.hardening +++ b/security/Kconfig.hardening @@ -121,6 +121,14 @@ choice endchoice +config HARDEN_SLS_ALL + bool "enable SLS vulnerability hardening" + depends on $(cc-option,-mharden-sls=all) + help + Enables straight-line speculation vulnerability hardening. This inserts + speculation barrier instruction sequences after certain unconditional jumps + to prevent speculative execution past those barriers. + config GCC_PLUGIN_STRUCTLEAK_VERBOSE bool "Report forcefully initialized variables" depends on GCC_PLUGIN_STRUCTLEAK