From: linux@armlinux.org.uk (Russell King - ARM Linux)
To: linux-arm-kernel@lists.infradead.org
Subject: arm: v4.18-rc5 with cpuidle on TC2 (A7 boot) spectre v2 issue
Date: Thu, 19 Jul 2018 11:01:10 +0100 [thread overview]
Message-ID: <20180719100109.GH17271@n2100.armlinux.org.uk> (raw)
In-Reply-To: <2abc6c11-2e8c-a4ea-6911-0f495d90ace6@arm.com>
On Thu, Jul 19, 2018 at 11:42:50AM +0200, Dietmar Eggemann wrote:
> Hi,
>
> running v4.18-rc5 (plus still missing "power: vexpress: fix corruption in
> notifier registration", otherwise I get this rcu_sched stall issue) on TC2
> (A7 boot) with vanilla multi_v7_defconfig plus
> CONFIG_ARM_BIG_LITTLE_CPUIDLE=y gives me continuous:
>
> ...
> CPUX: Spectre v2: incorrect context switching function, system vulnerable
> ...
>
> messages.
>
> Work around is to disable CONFIG_HARDEN_BRANCH_PREDICTOR.
or disable big.Little if you want the hardening.
The choices are currently either protection against Spectre or big.Little
support since the two are mutually exclusive at the moment.
--
RMK's Patch system: http://www.armlinux.org.uk/developer/patches/
FTTC broadband for 0.8mile line in suburbia: sync at 13.8Mbps down 630kbps up
According to speedtest.net: 13Mbps down 490kbps up
next prev parent reply other threads:[~2018-07-19 10:01 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-07-19 9:42 arm: v4.18-rc5 with cpuidle on TC2 (A7 boot) spectre v2 issue Dietmar Eggemann
2018-07-19 10:01 ` Russell King - ARM Linux [this message]
2018-07-19 10:39 ` Morten Rasmussen
2018-07-19 11:16 ` Russell King - ARM Linux
2018-07-19 13:32 ` Russell King - ARM Linux
2018-07-20 10:25 ` Morten Rasmussen
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20180719100109.GH17271@n2100.armlinux.org.uk \
--to=linux@armlinux.org.uk \
--cc=linux-arm-kernel@lists.infradead.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).