From: Dave Hansen <dave.hansen@intel.com>
To: Kevin Brodsky <kevin.brodsky@arm.com>, linux-hardening@vger.kernel.org
Cc: 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>,
Linus Walleij <linus.walleij@linaro.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, x86@kernel.org
Subject: Re: [RFC PATCH v2 00/15] pkeys-based page table hardening
Date: Thu, 9 Jan 2025 08:30:44 -0800 [thread overview]
Message-ID: <dcc1800c-cf0a-4d88-bc88-982f0709b382@intel.com> (raw)
In-Reply-To: <20250108103250.3188419-1-kevin.brodsky@arm.com>
One of the sticker things in the x86 attempt to do the same thing was
context switching, both between normal tasks and in/out of exceptions
and interrupts.
The easiest place this manifested for us was code chunk like this:
kpkeys_set_level(KPKEYS_LVL_PGTABLES);
// modify page tables here
kpkeys_restore_pkey_reg();
We had to make sure that we didn't get preempted and context switch over
to some other task that _wasn't_ doing page table manipulation while
page table writes were allowed.
On x86, we had to basically start context-switching the kernel pkey
register the same way we do GPRs.
How is SYS_POR_EL0 being context switched?
next prev parent reply other threads:[~2025-01-09 16:30 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-01-08 10:32 [RFC PATCH v2 00/15] pkeys-based page table hardening Kevin Brodsky
2025-01-08 10:32 ` [RFC PATCH v2 01/15] mm: Introduce kpkeys Kevin Brodsky
2025-01-08 10:32 ` [RFC PATCH v2 02/15] set_memory: Introduce set_memory_pkey() stub Kevin Brodsky
2025-01-08 10:32 ` [RFC PATCH v2 03/15] arm64: mm: Enable overlays for all EL1 indirect permissions Kevin Brodsky
2025-01-08 10:32 ` [RFC PATCH v2 04/15] arm64: Introduce por_set_pkey_perms() helper Kevin Brodsky
2025-01-08 10:32 ` [RFC PATCH v2 05/15] arm64: Implement asm/kpkeys.h using POE Kevin Brodsky
2025-01-08 10:32 ` [RFC PATCH v2 06/15] arm64: set_memory: Implement set_memory_pkey() Kevin Brodsky
2025-01-08 10:32 ` [RFC PATCH v2 07/15] arm64: Enable kpkeys Kevin Brodsky
2025-01-08 10:32 ` [RFC PATCH v2 08/15] mm: Introduce kernel_pgtables_set_pkey() Kevin Brodsky
2025-01-08 10:32 ` [RFC PATCH v2 09/15] mm: Introduce kpkeys_hardened_pgtables Kevin Brodsky
2025-01-08 10:32 ` [RFC PATCH v2 10/15] mm: Allow __pagetable_ctor() to fail Kevin Brodsky
2025-01-08 10:32 ` [RFC PATCH v2 11/15] mm: Map page tables with privileged pkey Kevin Brodsky
2025-01-08 10:32 ` [RFC PATCH v2 12/15] arm64: kpkeys: Support KPKEYS_LVL_PGTABLES Kevin Brodsky
2025-01-08 10:32 ` [RFC PATCH v2 13/15] arm64: mm: Guard page table writes with kpkeys Kevin Brodsky
2025-01-09 7:17 ` Qi Zheng
2025-01-10 14:05 ` Kevin Brodsky
2025-01-08 10:32 ` [RFC PATCH v2 14/15] arm64: Enable kpkeys_hardened_pgtables support Kevin Brodsky
2025-01-08 10:32 ` [RFC PATCH v2 15/15] mm: Add basic tests for kpkeys_hardened_pgtables Kevin Brodsky
2025-01-09 16:30 ` Dave Hansen [this message]
2025-01-13 10:10 ` [RFC PATCH v2 00/15] pkeys-based page table hardening Kevin Brodsky
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