From: Linus Walleij <linus.walleij@linaro.org>
To: Kevin Brodsky <kevin.brodsky@arm.com>
Cc: linux-hardening@vger.kernel.org, linux-kernel@vger.kernel.org,
Andrew Morton <akpm@linux-foundation.org>,
Mark Brown <broonie@kernel.org>,
Catalin Marinas <catalin.marinas@arm.com>,
Dave Hansen <dave.hansen@linux.intel.com>,
Jann Horn <jannh@google.com>, Jeff Xu <jeffxu@chromium.org>,
Joey Gouly <joey.gouly@arm.com>, Kees Cook <kees@kernel.org>,
Andy Lutomirski <luto@kernel.org>, Marc Zyngier <maz@kernel.org>,
Peter Zijlstra <peterz@infradead.org>,
Pierre Langlois <pierre.langlois@arm.com>,
Quentin Perret <qperret@google.com>,
"Mike Rapoport (IBM)" <rppt@kernel.org>,
Ryan Roberts <ryan.roberts@arm.com>,
Thomas Gleixner <tglx@linutronix.de>,
Will Deacon <will@kernel.org>,
Matthew Wilcox <willy@infradead.org>,
Qi Zheng <zhengqi.arch@bytedance.com>,
linux-arm-kernel@lists.infradead.org, linux-mm@kvack.org,
x86@kernel.org
Subject: Re: [RFC PATCH v3 08/15] mm: Introduce kernel_pgtables_set_pkey()
Date: Thu, 6 Feb 2025 20:01:34 +0100 [thread overview]
Message-ID: <CACRpkdZ_eGsfZh2vkG8dtSyZDbStMfDUuj7s7TQ4FcDwThJVkg@mail.gmail.com> (raw)
In-Reply-To: <20250203101839.1223008-9-kevin.brodsky@arm.com>
Hi Kevin,
thanks for your patch!
On Mon, Feb 3, 2025 at 11:20 AM Kevin Brodsky <kevin.brodsky@arm.com> wrote:
> kernel_pgtables_set_pkey() allows setting the pkey of all page table
> pages in swapper_pg_dir, recursively. This will be needed by
> kpkeys_hardened_pgtables, as it relies on all PTPs being mapped with
> a non-default pkey. Those initial kernel page tables cannot
> practically be assigned a non-default pkey right when they are
> allocated, so mutating them during (early) boot is required.
>
> Signed-off-by: Kevin Brodsky <kevin.brodsky@arm.com>
(...)
> +static int set_page_pkey(void *p, int pkey)
> +static int set_pkey_pte(pmd_t *pmd, int pkey)
> +static int set_pkey_pmd(pud_t *pud, int pkey)
> +static int set_pkey_pud(p4d_t *p4d, int pkey)
> +static int set_pkey_p4d(pgd_t *pgd, int pkey)
> +int kernel_pgtables_set_pkey(int pkey)
Aren't these all discardable after boot, so the whole set should
be tagged with __init?
Other than that it LGTM.
Yours,
Linus Walleij
next prev parent reply other threads:[~2025-02-06 19:01 UTC|newest]
Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-02-03 10:18 [RFC PATCH v3 00/15] pkeys-based page table hardening Kevin Brodsky
2025-02-03 10:18 ` [RFC PATCH v3 01/15] mm: Introduce kpkeys Kevin Brodsky
2025-02-03 10:18 ` [RFC PATCH v3 02/15] set_memory: Introduce set_memory_pkey() stub Kevin Brodsky
2025-02-03 10:18 ` [RFC PATCH v3 03/15] arm64: mm: Enable overlays for all EL1 indirect permissions Kevin Brodsky
2025-02-03 10:18 ` [RFC PATCH v3 04/15] arm64: Introduce por_set_pkey_perms() helper Kevin Brodsky
2025-02-03 10:18 ` [RFC PATCH v3 05/15] arm64: Implement asm/kpkeys.h using POE Kevin Brodsky
2025-02-03 10:18 ` [RFC PATCH v3 06/15] arm64: set_memory: Implement set_memory_pkey() Kevin Brodsky
2025-02-03 10:18 ` [RFC PATCH v3 07/15] arm64: Enable kpkeys Kevin Brodsky
2025-02-03 10:18 ` [RFC PATCH v3 08/15] mm: Introduce kernel_pgtables_set_pkey() Kevin Brodsky
2025-02-06 19:01 ` Linus Walleij [this message]
2025-02-07 14:33 ` Kevin Brodsky
2025-02-03 10:18 ` [RFC PATCH v3 09/15] mm: Introduce kpkeys_hardened_pgtables Kevin Brodsky
2025-02-03 10:18 ` [RFC PATCH v3 10/15] mm: Allow __pagetable_ctor() to fail Kevin Brodsky
2025-02-03 10:18 ` [RFC PATCH v3 11/15] mm: Map page tables with privileged pkey Kevin Brodsky
2025-02-03 10:18 ` [RFC PATCH v3 12/15] arm64: kpkeys: Support KPKEYS_LVL_PGTABLES Kevin Brodsky
2025-02-03 10:18 ` [RFC PATCH v3 13/15] arm64: mm: Guard page table writes with kpkeys Kevin Brodsky
2025-02-03 10:18 ` [RFC PATCH v3 14/15] arm64: Enable kpkeys_hardened_pgtables support Kevin Brodsky
2025-02-03 10:18 ` [RFC PATCH v3 15/15] mm: Add basic tests for kpkeys_hardened_pgtables Kevin Brodsky
2025-02-06 22:41 ` [RFC PATCH v3 00/15] pkeys-based page table hardening Kees Cook
2025-02-10 14:23 ` Kevin Brodsky
2025-02-13 14:54 ` Kevin Brodsky
2025-03-06 16:23 ` Maxwell Bland
2025-03-13 12:32 ` Kevin Brodsky
2025-03-19 21:54 ` Maxwell Bland
2025-03-25 17:11 ` Kevin Brodsky
2025-03-28 16:15 ` Maxwell Bland
2025-04-04 7:57 ` Kevin Brodsky
2025-04-14 22:43 ` Maxwell Bland
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