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 991393DF018 for ; Tue, 26 May 2026 11:18:26 +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=1779794307; cv=none; b=r/vJ1kb88JVNBg+/9VKjz6Xi4GAIWL34c1pwhh0k+LBB2QivbordwySR37/B9Yk/vNq2OM0B8ip+pfC8fdrUemHipkAWgsosOyS7INjNmfinCkNepwUudae3j/X4L13ks4C9AhslgbWwyypeo9mwXPd/W6Ou7K9h0VsqU6Z3feQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779794307; c=relaxed/simple; bh=Ksvs4ETYtArM4OpjEpTgUeDGNdsc/o015KS8Xfe06BU=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=ij+lRnZ7gxHcmWcz+cVGJvXvRAX6JN5zu2qUoFiobWLoKMGrQuP0GXkELENkjNSqKCKNNMGxvPCrGLyjA68dOgdznP2yq3sMMohRq7rzaIrWLiTam34EiAWQDnsON1l8SLRKeV3ZZ38UW7G1FiJL6aimUFXXEUIURSvWVgRTnlY= 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=f//46ng0; 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="f//46ng0" 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 E96A2169C; Tue, 26 May 2026 04:18:20 -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 27FF93F7D8; Tue, 26 May 2026 04:18:21 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=arm.com; s=foss; t=1779794306; bh=Ksvs4ETYtArM4OpjEpTgUeDGNdsc/o015KS8Xfe06BU=; h=From:Date:Subject:References:In-Reply-To:To:Cc:From; b=f//46ng0yqzXyYbz5KWfhQJnZiDBCx6Rl/sbBf8Rff2ghq58j0APCVuPAndxPLwhu 2jLygnKRBglQjL5M/9SLsXH8i6qwBsm7E3JigQ5taE1rvTutuRf5ktw1U6+xar480t apzsdI4JWV3NqrH9OX/RukkpJJV/EsnBlMIaTfUk= From: Kevin Brodsky Date: Tue, 26 May 2026 12:16:06 +0100 Subject: [PATCH RFC v8 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: <20260526-kpkeys-v8-17-eaaacdacc67c@arm.com> References: <20260526-kpkeys-v8-0-eaaacdacc67c@arm.com> In-Reply-To: <20260526-kpkeys-v8-0-eaaacdacc67c@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 , Vlastimil Babka , Will Deacon , Yang Shi , Yeoreum Yun , linux-arm-kernel@lists.infradead.org, linux-mm@kvack.org, x86@kernel.org, Lorenzo Stoakes , Thomas Gleixner X-Mailer: b4 0.15.2 X-Developer-Signature: v=1; a=ed25519-sha256; t=1779794212; l=1216; i=kevin.brodsky@arm.com; s=20260427; h=from:subject:message-id; bh=Ksvs4ETYtArM4OpjEpTgUeDGNdsc/o015KS8Xfe06BU=; b=HOtK9mBM/YEa1W1AKAgO/LbBhIoiZcz/bGtMqz+cFwafME0nEaGnjIA7ihVVbSs2asa0ZyTDx aJfHsBOF6KCCH74QPffHPLJRZ8lklx5Qz5Ia1O7GPTzyisbDFDX3/df 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 fdf3ebe92810..c1daab643195 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