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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 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 X-Rspamd-Server: rspam10 X-Stat-Signature: miqe3g3nqunaq43q3g96g93xtg8tq8k4 X-Rspam-User: X-Rspamd-Queue-Id: 774E01C0004 X-HE-Tag: 1776436688-794676 X-HE-Meta: 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 LdRTgqFT I7wjCYPSMOnnCzHtQLkIgJKILBj0j+5tsA3xhNNPNa7laJypuG6bG6Q1/5GhIJJl6Yz8Btzs7qdS7Z4QON+gEi3WGTJxkOz6IT/WDx8o9FmYM7wWS2kjJ7InugKC5UWMWDm7BdtKf2Rfvsi0o7h8euDsHEAKMjj1GxFX/rDBxVGfSnuM5ASGmzKMZw7hGZQ570Nqb/FqfDC9QSZmNnXEeyJs8gSUUrVmwxmI6//18n6UXqaV2YfsICULZ8LP6dt6XmIrD Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: 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