From patchwork Mon Feb 3 10:18:29 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kevin Brodsky X-Patchwork-Id: 13957208 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id EB064201016; Mon, 3 Feb 2025 10:20:01 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.140.110.172 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1738578003; cv=none; b=Ghkyg4k00gF9AC5pI9YPWji0378jzwS//aIp4jL+WNaLVsI1bxJcRvNDK70/qdsPvkqcjdzUmC3mi2LJrO2sBr1IJ3NTlUXpQTzsY62GJ0UmeWDWrkZfglcE3TS+SzgdSKSmrIzMHXjkoYI5P9Nh2bVgSSayPSgf6MFXbc4fPw0= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1738578003; c=relaxed/simple; bh=ADi3c0PRpU2JemlHu/u0oUZ4vDQkss9aFXz31FTjnBw=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=NVRrht3dkJQx+J9s/1CQjfNtUX6RC4dayQn7rrlu/sV9ZaecBrOFaLVKeRNOyTwu3OM3MAM1Qi7agmPa8qwtaYva0B8rF/0oXc4gebROqBs6HaaF5mLD7koMczFK7maS8z117lGuSntB1GHqAQIj3Apwh7EHxao28uTwBL2Rm2Q= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com; spf=pass smtp.mailfrom=arm.com; arc=none smtp.client-ip=217.140.110.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com 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 92D9D1476; Mon, 3 Feb 2025 02:20:25 -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 A14E23F63F; Mon, 3 Feb 2025 02:19:57 -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, linux-mm@kvack.org, x86@kernel.org Subject: [RFC PATCH v3 05/15] arm64: Implement asm/kpkeys.h using POE Date: Mon, 3 Feb 2025 10:18:29 +0000 Message-ID: <20250203101839.1223008-6-kevin.brodsky@arm.com> X-Mailer: git-send-email 2.47.0 In-Reply-To: <20250203101839.1223008-1-kevin.brodsky@arm.com> References: <20250203101839.1223008-1-kevin.brodsky@arm.com> Precedence: bulk X-Mailing-List: linux-hardening@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 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 */