From: James Morse <james.morse@arm.com>
To: John Garry <john.garry@huawei.com>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>,
Catalin Marinas <catalin.marinas@arm.com>,
Will Deacon <will.deacon@arm.com>, Linuxarm <linuxarm@huawei.com>,
"Guohanjun \(Hanjun Guo\)" <guohanjun@huawei.com>,
linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH] arm64: kpti: Update arm64_kernel_use_ng_mappings() when forced on
Date: Wed, 16 Jan 2019 10:33:00 +0000 [thread overview]
Message-ID: <5218967d-e12b-7eff-6d93-7feda563267a@arm.com> (raw)
In-Reply-To: <21310b0b-8a75-1adf-a844-b2f3f520fa2d@huawei.com>
Hi John,
On 16/01/2019 09:38, John Garry wrote:
> On 15/01/2019 18:49, James Morse wrote:
>> Since commit b89d82ef01b3 ("arm64: kpti: Avoid rewriting early page
>
> About b89d82ef01b3, I got an *unconfirmed* (emphasis on this, I don't want to
> cry wolf) report yesterday that the symptom I saw (boot delay) has been seen on
> 5.0-rc2 on our D06 board. I could not see it.
You can still cause kpti_install_ng_mappings() to rewrite the page-tables if you
don't have CONFIG_RANDOMIZE_BASE (or there is no seed), so its not enabled
early, and unmap_kernel_at_el0() thinks the CPU is vulnerable, so enables it late.
> Please note that this would be same board which we saw this on:
> https://lkml.org/lkml/2018/6/20/589
>
> I only witnessed the issue on the predecessor A72-based D05 board.
2a355ec25729 whitelisted the CPUs on this board. Unless you force kpti on, and
disable KASLR you shouldn't see it.
> The reporter is very busy, but we'll keep tabs on it.
Thanks!
James
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
next prev parent reply other threads:[~2019-01-16 10:33 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-01-15 18:49 [PATCH] arm64: kpti: Update arm64_kernel_use_ng_mappings() when forced on James Morse
2019-01-16 9:38 ` John Garry
2019-01-16 10:33 ` James Morse [this message]
[not found] ` <835dc899-578c-d914-4ed3-fa8b3b391ae6@huawei.com>
2019-03-01 11:35 ` Will Deacon
2019-03-01 11:43 ` Ard Biesheuvel
2019-03-01 11:45 ` Will Deacon
2019-03-01 11:46 ` Ard Biesheuvel
2019-03-01 12:59 ` Hanjun Guo
2019-03-01 13:02 ` Will Deacon
2019-03-01 13:34 ` Hanjun Guo
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=5218967d-e12b-7eff-6d93-7feda563267a@arm.com \
--to=james.morse@arm.com \
--cc=ard.biesheuvel@linaro.org \
--cc=catalin.marinas@arm.com \
--cc=guohanjun@huawei.com \
--cc=john.garry@huawei.com \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linuxarm@huawei.com \
--cc=will.deacon@arm.com \
/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).