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 247CF3321BD for ; Tue, 26 May 2026 11:18:36 +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=1779794318; cv=none; b=D9gzAhbe5sOaHqp4zQpOk/pOw1qrirBrIFQ829O5vDh765d6UfUxHoI9FgDlssXMgSvYP6qF31NYAxRQ9wf8kfDy0/NJD2BZxPP72mkLnAxMXC1uqjbFWrzIIR0udiXxnmDqpCd3IlQOUblR14/JU1QTB6thTGBfu7CIUDCKVm4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779794318; c=relaxed/simple; bh=9wBueeoIAFIdpCFPeoLi/EZkGlpSFOkAKC8me35KoYQ=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=j6NwlKrMosrOYIRHSk2uGfPiP9PPK2V8emmSxhzaJTiC+WZgIjm94VoqvgpWGf1J2AfWiSQXXgAAdVfnE5D1bENtSyqwbMEuJJ3t7xV6j1QJ6SSNLj/F7A5t5ZjuIhVFrexTgorXCB/RAcI3ru2lYhdbEtcw7ueposoe83NMnSc= 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=eXOLH7Md; 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="eXOLH7Md" 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 5820A169C; Tue, 26 May 2026 04:18:31 -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 8CC293F7D8; Tue, 26 May 2026 04:18:31 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=arm.com; s=foss; t=1779794316; bh=9wBueeoIAFIdpCFPeoLi/EZkGlpSFOkAKC8me35KoYQ=; h=From:Date:Subject:References:In-Reply-To:To:Cc:From; b=eXOLH7MdxJiOkZAP09iP5uw9iCgsxj2We3+sJWtQmd8d061E+2loD2GFwpxMovdHs LkkJNWWWTbLMzrvvXKCOGN9snp9rVpHRftvn//W84DGsK8vZ3pfuDtOV20nXYNOXgx KEnsow/YXuphRzS2h1zxu8OS9NOsZUePYgmR8K38= From: Kevin Brodsky Date: Tue, 26 May 2026 12:16:08 +0100 Subject: [PATCH RFC v8 19/24] arm64: kpkeys: Protect early page tables 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-v8-19-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=1150; i=kevin.brodsky@arm.com; s=20260427; h=from:subject:message-id; bh=9wBueeoIAFIdpCFPeoLi/EZkGlpSFOkAKC8me35KoYQ=; b=hUZ4Yyz5aVs6xpjZ1bdjTDRJfpeVGlGiY3rWKsG5Z1xMA/LMf3Vg/P8KbC4MF9EHQU3Mnw9ah fidBllv5ILqAMkofFH+F/kdGsTqbbi3lJBwRm6AiQE+GRrMzYmyWRch X-Developer-Key: i=kevin.brodsky@arm.com; a=ed25519; pk=N2QG+eJKrvkNovwhhwJhnJ4+ScVfsGCHldmqLfcMTFs= Use the dedicated kpkeys allocator for early page tables (used to create the linear map) when the kpkeys_hardened_pgtables feature is enabled. CPU features have not been detected at this stage so we use the early_enabled() helper. This is not a concern as kpkeys_physmem_pgtable_alloc() does not itself use POE or set_memory_pkey(). Signed-off-by: Kevin Brodsky --- arch/arm64/mm/mmu.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c index c67b46592af6..a9cc189affd8 100644 --- a/arch/arm64/mm/mmu.c +++ b/arch/arm64/mm/mmu.c @@ -109,8 +109,11 @@ static phys_addr_t __init early_pgtable_alloc(enum pgtable_level pgtable_level) { phys_addr_t phys; - phys = memblock_phys_alloc_range(PAGE_SIZE, PAGE_SIZE, 0, - MEMBLOCK_ALLOC_NOLEAKTRACE); + if (kpkeys_hardened_pgtables_early_enabled()) + phys = kpkeys_physmem_pgtable_alloc(); + else + phys = memblock_phys_alloc_range(PAGE_SIZE, PAGE_SIZE, 0, + MEMBLOCK_ALLOC_NOLEAKTRACE); if (!phys) panic("Failed to allocate page table page\n"); -- 2.51.2