From: catalin.marinas@arm.com (Catalin Marinas)
To: linux-arm-kernel@lists.infradead.org
Subject: [kernel-hardening] [PATCH 0/7] arm64: Privileged Access Never using TTBR0_EL1 switching
Date: Mon, 15 Aug 2016 11:52:06 +0100 [thread overview]
Message-ID: <20160815105205.GD22320@e104818-lin.cambridge.arm.com> (raw)
In-Reply-To: <CAKv+Gu-5Ckd0_ot-Le=7dL2Wn8E6198vEHPk0-E4VtRUw8c0BQ@mail.gmail.com>
On Mon, Aug 15, 2016 at 12:43:31PM +0200, Ard Biesheuvel wrote:
> But, how about we store the reserved ASID in TTBR1_EL1 instead, and
> switch TCR_EL1.A1 and TCR_EL1.EPD0 in a single write? That way, we can
> switch ASIDs and disable table walks atomically (I hope), and we
> wouldn't need to change TTBR0_EL1 at all.
I did this before for AArch32 + LPAE (patches on the list sometime last
year I think). But the idea was nak'ed by the ARM architects. The
TCR_EL1.A1 can be cached somewhere in the TLB state machine, so you need
TLBI (IOW, toggling A1 does not guarantee an ASID switch).
--
Catalin
next prev parent reply other threads:[~2016-08-15 10:52 UTC|newest]
Thread overview: 37+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-08-12 15:27 [PATCH 0/7] arm64: Privileged Access Never using TTBR0_EL1 switching Catalin Marinas
2016-08-12 15:27 ` [PATCH 1/7] arm64: Factor out PAN enabling/disabling into separate uaccess_* macros Catalin Marinas
2016-08-12 15:27 ` [PATCH 2/7] arm64: Factor out TTBR0_EL1 setting into a specific asm macro Catalin Marinas
2016-08-12 15:27 ` [PATCH 3/7] arm64: Introduce uaccess_{disable, enable} functionality based on TTBR0_EL1 Catalin Marinas
2016-08-12 15:27 ` [PATCH 4/7] arm64: Disable TTBR0_EL1 during normal kernel execution Catalin Marinas
2016-08-15 11:18 ` Mark Rutland
2016-08-15 16:39 ` Catalin Marinas
2016-08-12 15:27 ` [PATCH 5/7] arm64: Handle faults caused by inadvertent user access with PAN enabled Catalin Marinas
2016-08-12 15:27 ` [PATCH 6/7] arm64: xen: Enable user access before a privcmd hvc call Catalin Marinas
2016-08-15 9:58 ` Julien Grall
2016-08-15 18:00 ` Stefano Stabellini
2016-08-12 15:27 ` [PATCH 7/7] arm64: Enable CONFIG_ARM64_TTBR0_PAN Catalin Marinas
2016-08-12 18:04 ` [PATCH 0/7] arm64: Privileged Access Never using TTBR0_EL1 switching Kees Cook
2016-08-12 18:22 ` Catalin Marinas
2016-08-13 9:13 ` [kernel-hardening] " Ard Biesheuvel
2016-08-15 9:48 ` Catalin Marinas
2016-08-15 9:58 ` Mark Rutland
2016-08-15 10:02 ` Ard Biesheuvel
2016-08-15 10:06 ` Mark Rutland
2016-08-15 10:10 ` Will Deacon
2016-08-15 10:15 ` Mark Rutland
2016-08-15 10:21 ` Will Deacon
2016-08-15 10:21 ` Ard Biesheuvel
2016-08-15 10:30 ` Will Deacon
2016-08-15 10:31 ` Ard Biesheuvel
2016-08-15 10:37 ` Will Deacon
2016-08-15 10:43 ` Ard Biesheuvel
2016-08-15 10:52 ` Catalin Marinas [this message]
2016-08-15 10:56 ` Ard Biesheuvel
2016-08-15 11:02 ` Will Deacon
2016-08-15 16:13 ` Catalin Marinas
2016-08-15 19:04 ` Ard Biesheuvel
2016-08-15 11:00 ` Will Deacon
2016-08-15 10:30 ` Mark Rutland
2016-08-15 10:08 ` Will Deacon
2016-08-26 15:39 ` David Brown
2016-08-26 17:24 ` Catalin Marinas
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