From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 AFD753B27F6; Fri, 17 Apr 2026 14:38:07 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1776436687; cv=none; b=V9D5VK3XU/UmM5l/yE3ekNFlRPIROLEaLbHRgJ8NAP7E9Q5u+ZRxCmRmn3DuGhfI2wLl6rb8Ujeon+sceyiYaOzRrFOYjNooAQ9/Oz30fguz12FKWUFpTr3hhCXJGZaikblK5JKgHNY34IGnFrWQK6/HOVwFj3gaPS4ioiAzlJI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1776436687; c=relaxed/simple; bh=71fI7RYCKU2/+pXbICCBe4Ry1z/5h9g3tXZ1OoB1U/0=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=rqmxH/pTtNXIWCeWFbQp3vS1L+D5e9d2GbbeWzoQLF/g8D9rvkME1bR1QG4+GOD4m2cszBJqtbZcRyc7ejwPcGDjmyIn0nnuYrxkRU2cx/qqnGNUUwIXCVD8m/oeeW8BjZeWYAdPaJQuzXk76k4uHEV2avzu1pCJx9GwGN59BjU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=qhWujADd; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="qhWujADd" Received: by smtp.kernel.org (Postfix) with ESMTPSA id A5B2EC19425; Fri, 17 Apr 2026 14:38:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1776436687; bh=71fI7RYCKU2/+pXbICCBe4Ry1z/5h9g3tXZ1OoB1U/0=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=qhWujADdKcxaZq684kVHsaixqi43r/+f8Y1XaTTTq0IwyZ1W8nBK3UeRlRM0uD1uJ fqC8lfgLKFwv9mL88pW9wUWubXkwgxoNc1nUFE/KuuZ5kkHdvYSaj2uMPk4v/6SBBv 4txQqVgAu3KAqmGjtbj4R+96nromnLjZEMjnjXYM9K0FpYVHZdU0pwOKAisqNhm3qz jyTOHmjPpWKs0hUO4y4T+SptGdjS8GWMR8i9xS4ylx/9AK/Ac49ghXdwZJUcv0rpqj mOwZ9DEkTWYl9yCe9TZTgKMZD3LgrupjSR9NB52nHpKDt7Fz3l3IUzRH7rohQsAtni NO+5o5ZDjWo7w== Message-ID: <00b24db8-0063-48d6-8bc4-e8b670d8f0d5@kernel.org> Date: Fri, 17 Apr 2026 16:37:58 +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 v6 01/30] mm: Introduce kpkeys To: Kevin Brodsky , linux-hardening@vger.kernel.org Cc: linux-kernel@vger.kernel.org, Andrew Morton , Andy Lutomirski , Catalin Marinas , Dave Hansen , Ira Weiny , Jann Horn , Jeff Xu , Joey Gouly , Kees Cook , Linus Walleij , Lorenzo Stoakes , Marc Zyngier , Mark Brown , Matthew Wilcox , Maxwell Bland , "Mike Rapoport (IBM)" , Peter Zijlstra , Pierre Langlois , Quentin Perret , Rick Edgecombe , Ryan Roberts , Thomas Gleixner , Vlastimil Babka , Will Deacon , Yang Shi , Yeoreum Yun , linux-arm-kernel@lists.infradead.org, linux-mm@kvack.org, x86@kernel.org References: <20260227175518.3728055-1-kevin.brodsky@arm.com> <20260227175518.3728055-2-kevin.brodsky@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 2/27/26 18:54, Kevin Brodsky wrote: > kpkeys is a simple framework to enable the use of protection keys > (pkeys) to harden the kernel itself. This patch introduces the basic > API in : a couple of functions to set and restore > the pkey register and macros to define guard objects. > > kpkeys introduces a new concept on top of pkeys: the kpkeys level. > Each level is associated to a set of permissions for the pkeys > managed by the kpkeys framework. kpkeys_set_level(lvl) sets those > permissions according to lvl, and returns the original pkey > register, to be later restored by kpkeys_restore_pkey_reg(). To > start with, only KPKEYS_LVL_DEFAULT is available, which is meant > to grant RW access to KPKEYS_PKEY_DEFAULT (i.e. all memory since > this is the only available pkey for now). > > Because each architecture implementing pkeys uses a different > representation for the pkey register, and may reserve certain pkeys > for specific uses, support for kpkeys must be explicitly indicated > by selecting ARCH_HAS_KPKEYS and defining the following functions in > , in addition to the macros provided in > : > > - arch_kpkeys_set_level() > - arch_kpkeys_restore_pkey_reg() > - arch_kpkeys_enabled() Another thing: why not simply drop the "arch_" stuff from these helpers? -- Cheers, David