From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 3BF5C48AE04 for ; Tue, 5 May 2026 16:08:21 +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=1777997302; cv=none; b=t8aLEtOsZzA/mX2rXv4n8JWYP39Q6GfvmQKydnvF4+CT1a3ud4RGNg9IyzhGxhwi4WSnq+n4D9vmGbsI2Cttyd8w3aUEPzxq/m3hFekVMlCn5oAmT3Gh78b1wFBx2AaOLreMxEo+0W/MmqkPfQYFXFbeIVNdlEcQRMNKZqPOz0Y= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1777997302; c=relaxed/simple; bh=omwCAkmx3thEkpkTqNX8z5wj8c3+qOTHKO6WhZwka58=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=jG3wHsNs19NGswtvUVxf9M/Tp9x8R6g6TydOCczYTNzBwIxsLbkb1vDDDHD05cjY3gOolFsa4gaT1hzpa2HbtkL+AE/dXCLzIVRCkMz5BAI3SVr3ZgkQjNnJ0k65Licbv1OIEOaZVe9yKJrR0bgMwv00koxp+ELuXMHvdqC7pQg= 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; dkim=pass (1024-bit key) header.d=arm.com header.i=@arm.com header.b=bE7gISU0; 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 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=arm.com header.i=@arm.com header.b="bE7gISU0" 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 4394A14BF; Tue, 5 May 2026 09:08:15 -0700 (PDT) Received: from localhost.localdomain (e123572-lin.cambridge.arm.com [10.1.194.54]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 7C7253F763; Tue, 5 May 2026 09:08:16 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=arm.com; s=foss; t=1777997300; bh=omwCAkmx3thEkpkTqNX8z5wj8c3+qOTHKO6WhZwka58=; h=From:Date:Subject:References:In-Reply-To:To:Cc:From; b=bE7gISU03gq0h755odYFsgUzOaw6UDvswOcJVrHQb7PQhhWyk6yiq+HnvJuqZPmdb Fic9XDvc4cYQn3o6sKXeRw5zTwg5dq3jBAXKilBxXBvI+EicgvKmE9G8KFeMYsisYy npvWbqceXO+gbqx/NjShjbqNXvzlyo8KLckaSZGI= From: Kevin Brodsky Date: Tue, 05 May 2026 17:06:06 +0100 Subject: [PATCH RFC v7 17/24] arm64: kpkeys: Support KPKEYS_CTX_PGTABLES Precedence: bulk X-Mailing-List: linux-hardening@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Message-Id: <20260505-kpkeys-v7-17-20c0bdd97197@arm.com> References: <20260505-kpkeys-v7-0-20c0bdd97197@arm.com> In-Reply-To: <20260505-kpkeys-v7-0-20c0bdd97197@arm.com> To: linux-hardening@vger.kernel.org Cc: Kevin Brodsky , Andrew Morton , Andy Lutomirski , Catalin Marinas , Dave Hansen , "David Hildenbrand (Arm)" , Ira Weiny , Jann Horn , Jeff Xu , Joey Gouly , Kees Cook , Linus Walleij , Marc Zyngier , Mark Brown , Matthew Wilcox , Maxwell Bland , "Mike Rapoport (IBM)" , Peter Zijlstra , Pierre Langlois , Quentin Perret , Rick Edgecombe , Ryan Roberts , Will Deacon , Yang Shi , Yeoreum Yun , linux-arm-kernel@lists.infradead.org, linux-mm@kvack.org, x86@kernel.org, Lorenzo Stoakes , Thomas Gleixner , Vlastimil Babka X-Mailer: b4 0.15.2 X-Developer-Signature: v=1; a=ed25519-sha256; t=1777997220; l=1216; i=kevin.brodsky@arm.com; s=20260427; h=from:subject:message-id; bh=omwCAkmx3thEkpkTqNX8z5wj8c3+qOTHKO6WhZwka58=; b=zfUg7xwypSzq4NEGLAX1n6Kb71opGk8Ba4Dk+wrRWrE1XDWMw4FDZX+FCmdcwhWvH8K1snn4m v9noznHVB+MDzDbG8bhnCVOUWISyMPU0c1iJDQMs1vX4UbE0Q2tHNto X-Developer-Key: i=kevin.brodsky@arm.com; a=ed25519; pk=N2QG+eJKrvkNovwhhwJhnJ4+ScVfsGCHldmqLfcMTFs= Enable RW access to KPKEYS_PKEY_PGTABLES (used to map page table pages) if switching to KPKEYS_CTX_PGTABLES, otherwise only grant RO access. Signed-off-by: Kevin Brodsky --- arch/arm64/include/asm/kpkeys.h | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/arch/arm64/include/asm/kpkeys.h b/arch/arm64/include/asm/kpkeys.h index ea915f78936b..0c155b970582 100644 --- a/arch/arm64/include/asm/kpkeys.h +++ b/arch/arm64/include/asm/kpkeys.h @@ -12,7 +12,8 @@ * Equivalent to por_set_kpkeys_context(0, KPKEYS_CTX_DEFAULT), but can also be * used in assembly. */ -#define POR_EL1_INIT POR_ELx_PERM_PREP(KPKEYS_PKEY_DEFAULT, POE_RWX) +#define POR_EL1_INIT (POR_ELx_PERM_PREP(KPKEYS_PKEY_DEFAULT, POE_RWX) | \ + POR_ELx_PERM_PREP(KPKEYS_PKEY_PGTABLES, POE_R)) #ifndef __ASSEMBLY__ @@ -33,6 +34,8 @@ static inline bool arch_supports_kpkeys_early(void) static inline u64 por_set_kpkeys_context(u64 por, int ctx) { por = por_elx_set_pkey_perms(por, KPKEYS_PKEY_DEFAULT, POE_RWX); + por = por_elx_set_pkey_perms(por, KPKEYS_PKEY_PGTABLES, + ctx == KPKEYS_CTX_PGTABLES ? POE_RW : POE_R); return por; } -- 2.51.2