From: will.deacon@arm.com (Will Deacon)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH v3 02/13] arm64: Kconfig: Reword UNMAP_KERNEL_AT_EL0 kconfig entry
Date: Wed, 10 Jan 2018 19:26:11 +0000 [thread overview]
Message-ID: <20180110192610.GB9723@arm.com> (raw)
In-Reply-To: <20180109171700.GA18100@infradead.org>
On Tue, Jan 09, 2018 at 09:17:00AM -0800, Christoph Hellwig wrote:
> On Mon, Jan 08, 2018 at 05:32:27PM +0000, Will Deacon wrote:
> > Although CONFIG_UNMAP_KERNEL_AT_EL0 does make KASLR more robust, it's
> > actually more useful as a mitigation against speculation attacks that
> > can leak arbitrary kernel data to userspace through speculation.
> >
> > Reword the Kconfig help message to reflect this, and make the option
> > depend on EXPERT so that it is on by default for the majority of users.
>
> I still haven't heard an anwer on why this isn't using
> CONFIG_PAGE_TABLE_ISOLATION but instead reinvents its own symbol.
Mainly because this code was written before CONFIG_PAGE_TABLE_ISOLATION had
been proposed and I wanted to avoid confusion with the ongoing backports
just to align on the naming for an arch-specific config option. We could
CONFIG_PAGE_TABLE_ISOLATION and make it select CONFIG_UNMAP_KERNEL_AT_EL) if
you like, but worth noting that this is default 'y' anyway and depends on
EXPERT.
Will
WARNING: multiple messages have this Message-ID (diff)
From: Will Deacon <will.deacon@arm.com>
To: Christoph Hellwig <hch@infradead.org>
Cc: linux-arm-kernel@lists.infradead.org, catalin.marinas@arm.com,
ard.biesheuvel@linaro.org, marc.zyngier@arm.com,
lorenzo.pieralisi@arm.com, christoffer.dall@linaro.org,
linux-kernel@vger.kernel.org, shankerd@codeaurora.org,
jnair@caviumnetworks.com
Subject: Re: [PATCH v3 02/13] arm64: Kconfig: Reword UNMAP_KERNEL_AT_EL0 kconfig entry
Date: Wed, 10 Jan 2018 19:26:11 +0000 [thread overview]
Message-ID: <20180110192610.GB9723@arm.com> (raw)
In-Reply-To: <20180109171700.GA18100@infradead.org>
On Tue, Jan 09, 2018 at 09:17:00AM -0800, Christoph Hellwig wrote:
> On Mon, Jan 08, 2018 at 05:32:27PM +0000, Will Deacon wrote:
> > Although CONFIG_UNMAP_KERNEL_AT_EL0 does make KASLR more robust, it's
> > actually more useful as a mitigation against speculation attacks that
> > can leak arbitrary kernel data to userspace through speculation.
> >
> > Reword the Kconfig help message to reflect this, and make the option
> > depend on EXPERT so that it is on by default for the majority of users.
>
> I still haven't heard an anwer on why this isn't using
> CONFIG_PAGE_TABLE_ISOLATION but instead reinvents its own symbol.
Mainly because this code was written before CONFIG_PAGE_TABLE_ISOLATION had
been proposed and I wanted to avoid confusion with the ongoing backports
just to align on the naming for an arch-specific config option. We could
CONFIG_PAGE_TABLE_ISOLATION and make it select CONFIG_UNMAP_KERNEL_AT_EL) if
you like, but worth noting that this is default 'y' anyway and depends on
EXPERT.
Will
next prev parent reply other threads:[~2018-01-10 19:26 UTC|newest]
Thread overview: 48+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-01-08 17:32 [PATCH v3 00/13] arm64 kpti hardening and variant 2 workarounds Will Deacon
2018-01-08 17:32 ` Will Deacon
2018-01-08 17:32 ` [PATCH v3 01/13] arm64: use RET instruction for exiting the trampoline Will Deacon
2018-01-08 17:32 ` Will Deacon
2018-01-08 17:32 ` [PATCH v3 02/13] arm64: Kconfig: Reword UNMAP_KERNEL_AT_EL0 kconfig entry Will Deacon
2018-01-08 17:32 ` Will Deacon
2018-01-09 17:17 ` Christoph Hellwig
2018-01-09 17:17 ` Christoph Hellwig
2018-01-10 19:26 ` Will Deacon [this message]
2018-01-10 19:26 ` Will Deacon
2018-01-08 17:32 ` [PATCH v3 03/13] arm64: Take into account ID_AA64PFR0_EL1.CSV3 Will Deacon
2018-01-08 17:32 ` Will Deacon
2018-01-08 17:32 ` [PATCH v3 04/13] arm64: cpufeature: Pass capability structure to ->enable callback Will Deacon
2018-01-08 17:32 ` Will Deacon
2018-01-08 17:32 ` [PATCH v3 05/13] drivers/firmware: Expose psci_get_version through psci_ops structure Will Deacon
2018-01-08 17:32 ` Will Deacon
2018-01-08 17:32 ` [PATCH v3 06/13] arm64: Move post_ttbr_update_workaround to C code Will Deacon
2018-01-08 17:32 ` Will Deacon
2018-01-08 17:32 ` [PATCH v3 07/13] arm64: Add skeleton to harden the branch predictor against aliasing attacks Will Deacon
2018-01-08 17:32 ` Will Deacon
2018-01-09 12:55 ` Philippe Ombredanne
2018-01-09 12:55 ` Philippe Ombredanne
2018-01-08 17:32 ` [PATCH v3 08/13] arm64: KVM: Use per-CPU vector when BP hardening is enabled Will Deacon
2018-01-08 17:32 ` Will Deacon
2018-01-08 17:32 ` [PATCH v3 09/13] arm64: KVM: Make PSCI_VERSION a fast path Will Deacon
2018-01-08 17:32 ` Will Deacon
2018-01-08 17:32 ` [PATCH v3 10/13] arm64: cputype: Add missing MIDR values for Cortex-A72 and Cortex-A75 Will Deacon
2018-01-08 17:32 ` Will Deacon
2018-01-08 17:32 ` [PATCH v3 11/13] arm64: Implement branch predictor hardening for affected Cortex-A CPUs Will Deacon
2018-01-08 17:32 ` Will Deacon
2018-01-09 16:12 ` Suzuki K Poulose
2018-01-09 16:12 ` Suzuki K Poulose
2018-01-15 11:51 ` Marc Zyngier
2018-01-15 11:51 ` Marc Zyngier
2018-01-15 18:01 ` Catalin Marinas
2018-01-15 18:01 ` Catalin Marinas
2018-01-08 17:32 ` [PATCH v3 12/13] arm64: Implement branch predictor hardening for Falkor Will Deacon
2018-01-08 17:32 ` Will Deacon
2018-01-12 17:58 ` Shanker Donthineni
2018-01-12 17:58 ` Shanker Donthineni
2018-01-08 17:32 ` [PATCH v3 13/13] arm64: cputype: Add MIDR values for Cavium ThunderX2 CPUs Will Deacon
2018-01-08 17:32 ` Will Deacon
2018-01-08 18:53 ` [PATCH v3 00/13] arm64 kpti hardening and variant 2 workarounds Catalin Marinas
2018-01-08 18:53 ` Catalin Marinas
2018-01-09 14:07 ` Matthias Brugger
2018-01-09 14:07 ` Matthias Brugger
2018-01-12 15:58 ` Catalin Marinas
2018-01-12 15:58 ` Catalin Marinas
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