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=-10.0 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED,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 E4893C43331 for ; Fri, 27 Mar 2020 19:21:40 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (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 BD58420663 for ; Fri, 27 Mar 2020 19:21:40 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="INjqzK5A" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org BD58420663 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+infradead-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=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-Id:Date:Subject:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=UMoXrH+DxS91uLP+9TRWAaQ2hcsgWgKFXLsgvr8jPCg=; b=INjqzK5AzCxKgH y2YqlRdLu/EWAIwIjcVwk0sWZkqc7lyR4fu0XDF88nXu2R4Vs1VPMvkS7LIzz0H7FsLxwiz/3UI4n sgqzq1KcWxkM+2TRdC7LsgYvHlAQZAe14y2jVD5IpVRMKqYLixQbhCzroyLiI9+B7Kl8vtUrJZ51W 88g2pda8K73dEXYppfPZo9XReeCWglQQpryaeeH8QSssYlmCeDBJjzuZzawDOL6vPtvSzf9uk7v/w m1rX06de00CXtbKkekXdmGAYoSnXowN+GNjoesn/FUH46XMdW5cnsRDjmXy98Ms5gjcNo+eBOdjRH cIqYdX5clF9WQl90Dwow==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1jHuXv-0001tq-QP; Fri, 27 Mar 2020 19:21:35 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1jHuXi-0001es-A2 for linux-arm-kernel@lists.infradead.org; Fri, 27 Mar 2020 19:21:23 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id BF17A31B; Fri, 27 Mar 2020 12:21:21 -0700 (PDT) Received: from localhost (unknown [10.37.6.21]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 4046D3F85E; Fri, 27 Mar 2020 12:21:21 -0700 (PDT) From: Mark Brown To: Catalin Marinas , Will Deacon Subject: [PATCH 2/5] arm64: asm: Override SYM_FUNC_START when building the kernel with BTI Date: Fri, 27 Mar 2020 19:21:04 +0000 Message-Id: <20200327192107.18394-3-broonie@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20200327192107.18394-1-broonie@kernel.org> References: <20200327192107.18394-1-broonie@kernel.org> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20200327_122122_389375_15C757FD X-CRM114-Status: GOOD ( 10.40 ) 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 Brown , Kees Cook , linux-arm-kernel@lists.infradead.org Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org When the kernel is built for BTI override SYM_FUNC_START and related macros to add a BTI landing pad to the start of all global functions, ensuring that they are BTI safe. The ; at the end of the BTI_C macro is for the benefit of the macro-generated functions in xen-hypercall.S. Signed-off-by: Mark Brown --- arch/arm64/include/asm/linkage.h | 46 ++++++++++++++++++++++++++++++++ 1 file changed, 46 insertions(+) diff --git a/arch/arm64/include/asm/linkage.h b/arch/arm64/include/asm/linkage.h index ebee3113a62f..d8d5b0f77216 100644 --- a/arch/arm64/include/asm/linkage.h +++ b/arch/arm64/include/asm/linkage.h @@ -4,6 +4,52 @@ #define __ALIGN .align 2 #define __ALIGN_STR ".align 2" +#ifdef CONFIG_ARM64_BTI_KERNEL + +/* + * Since current versions of gas reject the BTI instruction unless we + * set the architecture version to v8.5 we use the hint instruction + * instead. + */ +#define BTI_C hint 34 ; +#define BTI_J hint 36 ; + +/* + * When using in-kernel BTI we need to ensure that assembly functions + * have suitable annotations. Override SYM_FUNC_START to insert a BTI + * landing pad at the start of everything. + */ +#define SYM_FUNC_START(name) \ + SYM_START(name, SYM_L_GLOBAL, SYM_A_ALIGN) \ + BTI_C + +#define SYM_FUNC_START_NOALIGN(name) \ + SYM_START(name, SYM_L_GLOBAL, SYM_A_NONE) \ + BTI_C + +#define SYM_FUNC_START_LOCAL(name) \ + SYM_START(name, SYM_L_LOCAL, SYM_A_ALIGN) \ + BTI_C + +#define SYM_FUNC_START_LOCAL_NOALIGN(name) \ + SYM_START(name, SYM_L_LOCAL, SYM_A_NONE) \ + BTI_C + +#define SYM_FUNC_START_WEAK(name) \ + SYM_START(name, SYM_L_WEAK, SYM_A_ALIGN) \ + BTI_C + +#define SYM_FUNC_START_WEAK_NOALIGN(name) \ + SYM_START(name, SYM_L_WEAK, SYM_A_NONE) \ + BTI_C + +#define SYM_INNER_LABEL(name, linkage) \ + .type name SYM_T_NONE ASM_NL \ + SYM_ENTRY(name, linkage, SYM_A_NONE) \ + BTI_J + +#endif + /* * Annotate a function as position independent, i.e., safe to be called before * the kernel virtual mapping is activated. -- 2.20.1 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel