From patchwork Wed May 6 19:51:28 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mark Brown X-Patchwork-Id: 11531757 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 BD54E92A for ; Wed, 6 May 2020 19:52:06 +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 9BB372076D for ; Wed, 6 May 2020 19:52:06 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="G1a4zkZ5"; dkim=fail reason="signature verification failed" (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="AelTKDdo" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 9BB372076D 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+patchwork-linux-arm=patchwork.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=jMdDLtIlVYnMH4lmq9yqmtxQ5ovLmSWDVXHly8XWIr4=; b=G1a4zkZ5rShdhy puuwgpmF4oXmYrOCIYE7lcYSdkGyjtUY6z+U5USlABTipIbTrmJA6lpAOBB4PY39X4wupRd5dFdpA ybxp0/PBETPuBB0NlU01vR4dNgTSI3tUBIciwOI4tjhAdDOaWhwISjn0JY2soz5t2YbIucU62dAe3 Ca4s3u1ZT40M1bGPCYXDJxNj7BYX55PXQpWgiuqyDcg4jXWo9aKa+B7vxzL1QkTJItSEhVOWkUvj2 Np22vxVd61Aei+axEDTKRzn/4Jo2oRNkS7qiIJ9NeyIW8b/hLx76+8L9LmDbDsCQ7AjqCFAiS9sLO H1dVMZ/vLyTVFHue4l/w==; 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 1jWQ5K-0003zw-CM; Wed, 06 May 2020 19:52:02 +0000 Received: from mail.kernel.org ([198.145.29.99]) by bombadil.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1jWQ5B-0003sO-U1 for linux-arm-kernel@lists.infradead.org; Wed, 06 May 2020 19:51:55 +0000 Received: from localhost (fw-tnat.cambridge.arm.com [217.140.96.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 164EA2076D; Wed, 6 May 2020 19:51:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1588794713; bh=Ka6XaeJFGLEHETAtkDTVNC8JD3X9bt0CjpNM2vX+44E=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=AelTKDdo52MGwmw3yPmTCHzbM/m0gL+xZLLRgceBJH7B+QJdalPrneLy6aS+Nxk53 4OilEM+cSdxqE365adbGTYN5Fjp6cU4aWhu8GShQKno8YyyLVQMTdjYwJ8bTuRZ5Lq sCFeNQB+C6EOSOtofEEFpX4TjT6C6SWpEUVoMH1Q= From: Mark Brown To: Vincenzo Frascino , Will Deacon , Catalin Marinas Subject: [PATCH v3 01/11] arm64: Document why we enable PAC support for leaf functions Date: Wed, 6 May 2020 20:51:28 +0100 Message-Id: <20200506195138.22086-2-broonie@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20200506195138.22086-1-broonie@kernel.org> References: <20200506195138.22086-1-broonie@kernel.org> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20200506_125153_987003_38359764 X-CRM114-Status: UNSURE ( 9.23 ) X-CRM114-Notice: Please train this message. X-Spam-Score: -5.2 (-----) X-Spam-Report: SpamAssassin version 3.4.4 on bombadil.infradead.org summary: Content analysis details: (-5.2 points) pts rule name description ---- ---------------------- -------------------------------------------------- -5.0 RCVD_IN_DNSWL_HI RBL: Sender listed at https://www.dnswl.org/, high trust [198.145.29.99 listed in list.dnswl.org] -0.0 SPF_PASS SPF: sender matches SPF record 0.0 SPF_HELO_NONE SPF: HELO does not publish an SPF Record -0.1 DKIM_VALID Message has at least one valid DKIM or DK signature -0.1 DKIM_VALID_AU Message has a valid DKIM or DK signature from author's domain -0.1 DKIM_VALID_EF Message has a valid DKIM or DK signature from envelope-from domain 0.1 DKIM_SIGNED Message has a DKIM or DK signature, not necessarily valid -0.0 DKIMWL_WL_HIGH DKIMwl.org - Whitelisted High sender 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: Kees Cook , Daniel Borkmann , Jean-Philippe Brucker , Mark Brown , Amit Kachhap , Dave Martin , linux-arm-kernel@lists.infradead.org Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org Document the fact that we enable pointer authentication protection for leaf functions since there is some narrow potential for ROP protection benefits and little overhead has been observed. Signed-off-by: Mark Brown --- arch/arm64/Makefile | 3 +++ 1 file changed, 3 insertions(+) diff --git a/arch/arm64/Makefile b/arch/arm64/Makefile index 85e4149cc5d5..921c8ee8552b 100644 --- a/arch/arm64/Makefile +++ b/arch/arm64/Makefile @@ -71,6 +71,9 @@ branch-prot-flags-y += $(call cc-option,-mbranch-protection=none) ifeq ($(CONFIG_ARM64_PTR_AUTH),y) branch-prot-flags-$(CONFIG_CC_HAS_SIGN_RETURN_ADDRESS) := -msign-return-address=all +# We enable additional protection for leaf functions as there is some +# narrow potential for ROP protection benefits and no substantial +# performance impact has been observed. branch-prot-flags-$(CONFIG_CC_HAS_BRANCH_PROT_PAC_RET) := -mbranch-protection=pac-ret+leaf # -march=armv8.3-a enables the non-nops instructions for PAC, to avoid the # compiler to generate them and consequently to break the single image contract