From: Marc Zyngier <maz@kernel•org>
To: Ard Biesheuvel <ardb@kernel•org>
Cc: rmk+kernel@armlinux•org.uk, linus.walleij@linaro•org,
linux-arm-kernel@lists•infradead.org
Subject: Re: [PATCH resend 0/2] ARM/decompressor: deal with disabled CP15 barrier instructions
Date: Thu, 07 Nov 2019 17:30:00 +0109 [thread overview]
Message-ID: <36e25caa345f95ff785a814fcba5778f@www.loen.fr> (raw)
In-Reply-To: <20191106104918.26397-1-ardb@kernel.org>
On 2019-11-06 11:58, Ard Biesheuvel wrote:
> [ Resending because --cc-cover didn't take ]
>
> While trying to test my v4.4 backport of the firmware/hypervisor
> based spectre
> v1/v2 mitigations for 32-bit ARM, I noticed that KVM/qemu failed to
> boot my
> kernel while it booted fine under TCG emulation.
>
> As it turns out, KVM/qemu may instantiate the VCPU with support for
> CP15
> barrier instructions disabled, causing them to UNDEF and crash the
> decompressor.
>
> I already fixed the same issue for UEFI boot, but since v4.4 does not
> support
> that, I only noticed now that this is an issue for bare metal as
> well.
>
> Cc: Russell King <rmk+kernel@armlinux•org.uk>
> Cc: Linus Walleij <linus.walleij@linaro•org>
> Cc: Marc Zyngier <maz@kernel•org>
>
> Ard Biesheuvel (2):
> ARM/decompressor: avoid CP15 barrier instructions in v7 cache setup
> code
> Revert "ARM: 8857/1: efi: enable CP15 DMB instructions before
> cleaning
> the cache"
>
> arch/arm/boot/compressed/head.S | 51 ++++++++++----------
> 1 file changed, 26 insertions(+), 25 deletions(-)
For the whole series:
Acked-by: Marc Zyngier <maz@kernel•org>
M.
--
Jazz is not dead. It just smells funny...
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prev parent reply other threads:[~2019-11-07 16:20 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-11-06 10:49 [PATCH resend 0/2] ARM/decompressor: deal with disabled CP15 barrier instructions Ard Biesheuvel
2019-11-06 10:49 ` [PATCH resend 1/2] ARM/decompressor: avoid CP15 barrier instructions in v7 cache setup code Ard Biesheuvel
2019-11-06 10:49 ` [PATCH resend 2/2] Revert "ARM: 8857/1: efi: enable CP15 DMB instructions before cleaning the cache" Ard Biesheuvel
2019-11-07 16:21 ` Marc Zyngier [this message]
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