From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 8E2FB3B0ACB for ; Mon, 22 Jun 2026 13:06:34 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1782133595; cv=none; b=X1zRGt7lVhOJEve/cJY95OSkriff9ZqZ/Jin9bwQMHJc8gvAno5hO1DrXaY4K9fX0PVt8hUlBKCwxgx7WjbGO2vLG0EszKW+iutn+t47y+1LuxovW0krjic6K6F2Lkb9RsSiu6qbwgc93Gn7wOfYvE7H3bdrChLflLy+nbSNrIQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1782133595; c=relaxed/simple; bh=ymtlc3AQrxEuaabeTzUwTgAjuHMloYfKcg9JlFh4YXk=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=IUHao1n3dNU69ggWeZqexiruTvu+3RM/rbsikeOcWCtSkQncyNF459FoiQR8ipIV0qHi8Etk3g1U7z3n+MHu8D8XMjDjO/iPhGgEGwYAnkUGmjSJ46XakIM7cnhepTDhQYWqMRqKwAd9pser/bjkzkAYpIYQQDfLV4UIf2hAxPA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=EVO3TrLz; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="EVO3TrLz" Received: by smtp.kernel.org (Postfix) with ESMTPSA id AF82F1F000E9; Mon, 22 Jun 2026 13:06:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1782133594; bh=sLW3835ooF/gyASPq4HfcxuD4xTqS9E83di9vyQnNuU=; h=Date:Subject:To:Cc:References:From:In-Reply-To; b=EVO3TrLz+bQjQqozayKpjazPXBGIy5tAHLEgjkJc5yRgHhuigoWiPudPbB7kB3uSE UtOB7y4258R1S8pmCtLnbYcOTWEOgS1mobD4Vp2ge358defYkyY8pQXmxRNwU15rV1 Ei+5Bo4/bRcahmSXjuouj9qFQs4cAbI2gW6BpP00CZ7W46vU8vs/AUyBRerlYuhUeb lN3nggcejKli1r/PdVvLluVgSkDo1kSQNWtxN6jdlzE5spv02okcBDbYdiSjyKf7Z4 J49g9/QL5cjv9luKHEhmdvKOLNQpWYbz9+abchACeNQfHOHgZoBWOmOgLYVDgLwj++ y8z5oo4KQuOuw== Message-ID: Date: Mon, 22 Jun 2026 15:06:24 +0200 Precedence: bulk X-Mailing-List: linux-hardening@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH RFC v8 03/24] arm64: mm: Enable overlays for all EL1 indirect permissions To: Kevin Brodsky , linux-hardening@vger.kernel.org Cc: Andrew Morton , Andy Lutomirski , Catalin Marinas , Dave Hansen , 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 References: <20260526-kpkeys-v8-0-eaaacdacc67c@arm.com> <20260526-kpkeys-v8-3-eaaacdacc67c@arm.com> From: "David Hildenbrand (Arm)" Content-Language: en-US Autocrypt: addr=david@kernel.org; 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charset=UTF-8 Content-Transfer-Encoding: 7bit On 5/26/26 13:15, Kevin Brodsky wrote: > In preparation of using POE inside the kernel, enable "Overlay > applied" for kernel memory types in PIR_EL1. This ensures that the > permissions set in POR_EL1 affect all kernel mappings. > > User memory types must be left untouched (overlays not applied) > because any privileged access to user memory (e.g. futex atomic > without FEAT_LSUI) would then be mistakenly checked against POR_EL1. That makes sense. Still learning the architecture, but ... leaving the user bits as is sounds good to me (and unrelated to using overlays for kernel memory). Reviewed-by: David Hildenbrand (Arm) > > Signed-off-by: Kevin Brodsky > --- > arch/arm64/include/asm/pgtable-prot.h | 8 ++++---- > 1 file changed, 4 insertions(+), 4 deletions(-) > > diff --git a/arch/arm64/include/asm/pgtable-prot.h b/arch/arm64/include/asm/pgtable-prot.h > index 212ce1b02e15..d4d45ab86a5a 100644 > --- a/arch/arm64/include/asm/pgtable-prot.h > +++ b/arch/arm64/include/asm/pgtable-prot.h > @@ -183,9 +183,9 @@ static inline bool __pure lpa2_is_enabled(void) > PIRx_ELx_PERM_PREP(pte_pi_index(_PAGE_SHARED_EXEC), PIE_RW) | \ > PIRx_ELx_PERM_PREP(pte_pi_index(_PAGE_READONLY), PIE_R) | \ > PIRx_ELx_PERM_PREP(pte_pi_index(_PAGE_SHARED), PIE_RW) | \ > - PIRx_ELx_PERM_PREP(pte_pi_index(_PAGE_KERNEL_ROX), PIE_RX) | \ > - PIRx_ELx_PERM_PREP(pte_pi_index(_PAGE_KERNEL_EXEC), PIE_RWX) | \ > - PIRx_ELx_PERM_PREP(pte_pi_index(_PAGE_KERNEL_RO), PIE_R) | \ > - PIRx_ELx_PERM_PREP(pte_pi_index(_PAGE_KERNEL), PIE_RW)) > + PIRx_ELx_PERM_PREP(pte_pi_index(_PAGE_KERNEL_ROX), PIE_RX_O) | \ > + PIRx_ELx_PERM_PREP(pte_pi_index(_PAGE_KERNEL_EXEC), PIE_RWX_O) | \ > + PIRx_ELx_PERM_PREP(pte_pi_index(_PAGE_KERNEL_RO), PIE_R_O) | \ > + PIRx_ELx_PERM_PREP(pte_pi_index(_PAGE_KERNEL), PIE_RW_O)) > > #endif /* __ASM_PGTABLE_PROT_H */ > -- Cheers, David