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 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 smtp.lore.kernel.org (Postfix) with ESMTPS id 27D66FEFB70 for ; Fri, 27 Feb 2026 17:56:42 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Transfer-Encoding: MIME-Version:References:In-Reply-To:Message-ID:Date:Subject:Cc:To:From: Reply-To:Content-Type:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=yvPuv6sH8ptnova1Tbtix8h3gQ7QoRRh+xxQudFszJY=; b=UAqvGbm6Erb2lXojjvqlwhdilS e6UR301+N5FWPhYGhsiARuy6n30gGRoyTFJw/HDF/qGLbQee0IEpxU6PWOfXBp0Z9c67Af5no0dHU nO0REIhT/R8gjqOXI+kwfuCn+3c0uW2LtUwDdeysUiaDg1n4IiENWfJ4NaVgQdjnAbIbdTSemj4ah 3ZUrpofSPipHW8j/QNBam6X/T5VW3TnhKkaJYdBzy/anFW1ljvLDqw9mMzN2Up7ywpspVSfq7VgDS eAGIJ7FeaWA3SYHs7onoQyiufx15kt6jC0/fsfZ8QNxuIhSvNN/smVWvXX3W/ZngXopnIWNzvdHQG D1iIvUeQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1vw24r-00000008qnJ-1c6O; Fri, 27 Feb 2026 17:56:37 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1vw24l-00000008qhi-3gOg for linux-arm-kernel@lists.infradead.org; Fri, 27 Feb 2026 17:56:33 +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 2D25D14BF; Fri, 27 Feb 2026 09:56:24 -0800 (PST) Received: from e123572-lin.arm.com (e123572-lin.cambridge.arm.com [10.1.194.54]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 1637B3F73B; Fri, 27 Feb 2026 09:56:25 -0800 (PST) From: Kevin Brodsky To: linux-hardening@vger.kernel.org Cc: linux-kernel@vger.kernel.org, Kevin Brodsky , Andrew Morton , Andy Lutomirski , Catalin Marinas , Dave Hansen , David Hildenbrand , Ira Weiny , Jann Horn , Jeff Xu , Joey Gouly , Kees Cook , Linus Walleij , Lorenzo Stoakes , Marc Zyngier , Mark Brown , Matthew Wilcox , Maxwell Bland , "Mike Rapoport (IBM)" , Peter Zijlstra , Pierre Langlois , Quentin Perret , Rick Edgecombe , Ryan Roberts , Thomas Gleixner , Vlastimil Babka , Will Deacon , Yang Shi , Yeoreum Yun , linux-arm-kernel@lists.infradead.org, linux-mm@kvack.org, x86@kernel.org Subject: [PATCH v6 10/30] arm64: Enable kpkeys Date: Fri, 27 Feb 2026 17:54:58 +0000 Message-ID: <20260227175518.3728055-11-kevin.brodsky@arm.com> X-Mailer: git-send-email 2.51.2 In-Reply-To: <20260227175518.3728055-1-kevin.brodsky@arm.com> References: <20260227175518.3728055-1-kevin.brodsky@arm.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260227_095631_990037_0AC1C3F3 X-CRM114-Status: GOOD ( 13.32 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org This is the final step to enable kpkeys on arm64. We enable POE at EL1 by setting TCR2_EL1.POE, and initialise POR_EL1 to the default value, enabling access to the default pkey/POIndex (0). An ISB is added so that POE restrictions are enforced immediately. Having done this, we can now select ARCH_HAS_KPKEYS if ARM64_POE is enabled. Signed-off-by: Kevin Brodsky --- arch/arm64/Kconfig | 1 + arch/arm64/kernel/cpufeature.c | 5 ++++- 2 files changed, 5 insertions(+), 1 deletion(-) diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index 38dba5f7e4d2..732d4dbbab20 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -2164,6 +2164,7 @@ config ARM64_POE def_bool y select ARCH_USES_HIGH_VMA_FLAGS select ARCH_HAS_PKEYS + select ARCH_HAS_KPKEYS help The Permission Overlay Extension is used to implement Memory Protection Keys. Memory Protection Keys provides a mechanism for diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c index c31f8e17732a..3b01a70b617b 100644 --- a/arch/arm64/kernel/cpufeature.c +++ b/arch/arm64/kernel/cpufeature.c @@ -76,6 +76,7 @@ #include #include #include +#include #include #include @@ -2447,8 +2448,10 @@ static void cpu_enable_mops(const struct arm64_cpu_capabilities *__unused) #ifdef CONFIG_ARM64_POE static void cpu_enable_poe(const struct arm64_cpu_capabilities *__unused) { - sysreg_clear_set(REG_TCR2_EL1, 0, TCR2_EL1_E0POE); + write_sysreg_s(POR_EL1_INIT, SYS_POR_EL1); + sysreg_clear_set(REG_TCR2_EL1, 0, TCR2_EL1_E0POE | TCR2_EL1_POE); sysreg_clear_set(CPACR_EL1, 0, CPACR_EL1_E0POE); + isb(); } #endif -- 2.51.2