From patchwork Wed Jan 8 10:32:40 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kevin Brodsky X-Patchwork-Id: 13930524 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 E687AE77188 for ; Wed, 8 Jan 2025 10:42:43 +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=Snhdnks8KmGT9o0/ZDnykraCyor+6xfRkmoZ7dE4fso=; b=lGWweXExjn0+VUEcXgvQ+2bb1H K6Iua9c4jMS+YuMttb9ZxVJ6ZjhU+bzC9CaCyzZSVe64hXkkW3NEDEdxdd3W8rkjsj5gOYu11ZGhv kjuA22waqfDVawGc0KqXDg+rdINvIJIFTSwdh0Fd2oOyMjtTIc1rPVmebEVWWTkoErj5azzczo48n /RpWkOtrm/7n21yeK4TJ7bhE33nafzJalgzYs83sTNgTJnTpEA+TeieaWI3mqYjx26+Dm/pUw5rqc agshBl/5MZiI4+edMbwbZLtX4B96f/CjsqvA5GTCcR5n5IcJGr01njkHvbB7ZHuGDdb3zkB42MZed PL4SPrlQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98 #2 (Red Hat Linux)) id 1tVTW9-00000008208-1DQ5; Wed, 08 Jan 2025 10:42:29 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.98 #2 (Red Hat Linux)) id 1tVTON-00000008063-08sW for linux-arm-kernel@lists.infradead.org; Wed, 08 Jan 2025 10:34:28 +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 B740513D5; Wed, 8 Jan 2025 02:34:53 -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 9D3B93F673; Wed, 8 Jan 2025 02:34:22 -0800 (PST) From: Kevin Brodsky To: linux-hardening@vger.kernel.org Cc: linux-kernel@vger.kernel.org, Kevin Brodsky , Andrew Morton , Mark Brown , Catalin Marinas , Dave Hansen , Jann Horn , Jeff Xu , Joey Gouly , Kees Cook , Linus Walleij , Andy Lutomirski , Marc Zyngier , Peter Zijlstra , Pierre Langlois , Quentin Perret , "Mike Rapoport (IBM)" , Ryan Roberts , Thomas Gleixner , Will Deacon , Matthew Wilcox , Qi Zheng , linux-arm-kernel@lists.infradead.org, x86@kernel.org Subject: [RFC PATCH v2 05/15] arm64: Implement asm/kpkeys.h using POE Date: Wed, 8 Jan 2025 10:32:40 +0000 Message-ID: <20250108103250.3188419-6-kevin.brodsky@arm.com> X-Mailer: git-send-email 2.47.0 In-Reply-To: <20250108103250.3188419-1-kevin.brodsky@arm.com> References: <20250108103250.3188419-1-kevin.brodsky@arm.com> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20250108_023427_107768_4685FD21 X-CRM114-Status: GOOD ( 13.59 ) 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 Implement the kpkeys interface if CONFIG_ARM64_POE is enabled. The permissions for KPKEYS_PKEY_DEFAULT (pkey 0) are set to RWX as this pkey is also used for code mappings. Signed-off-by: Kevin Brodsky --- arch/arm64/include/asm/kpkeys.h | 43 +++++++++++++++++++++++++++++++++ 1 file changed, 43 insertions(+) create mode 100644 arch/arm64/include/asm/kpkeys.h diff --git a/arch/arm64/include/asm/kpkeys.h b/arch/arm64/include/asm/kpkeys.h new file mode 100644 index 000000000000..e17f6df41873 --- /dev/null +++ b/arch/arm64/include/asm/kpkeys.h @@ -0,0 +1,43 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +#ifndef __ASM_KPKEYS_H +#define __ASM_KPKEYS_H + +#include +#include +#include + +#include + +static inline bool arch_kpkeys_enabled(void) +{ + return system_supports_poe(); +} + +#ifdef CONFIG_ARM64_POE + +static inline u64 por_set_kpkeys_level(u64 por, int level) +{ + por = por_set_pkey_perms(por, KPKEYS_PKEY_DEFAULT, POE_RXW); + + return por; +} + +static inline int arch_kpkeys_set_level(int level) +{ + u64 prev_por = read_sysreg_s(SYS_POR_EL1); + + write_sysreg_s(por_set_kpkeys_level(prev_por, level), SYS_POR_EL1); + isb(); + + return prev_por; +} + +static inline void arch_kpkeys_restore_pkey_reg(u64 pkey_reg) +{ + write_sysreg_s(pkey_reg, SYS_POR_EL1); + isb(); +} + +#endif /* CONFIG_ARM64_POE */ + +#endif /* __ASM_KPKEYS_H */