kvmarm.lists.cs.columbia.edu archive mirror
 help / color / mirror / Atom feed
From: Greg KH <gregkh@linuxfoundation.org>
To: Florian Fainelli <f.fainelli@gmail.com>
Cc: Nick Desaulniers <ndesaulniers@google.com>,
	Fangrui Song <maskray@google.com>,
	Catalin Marinas <catalin.marinas@arm.com>,
	Will Deacon <will.deacon@arm.com>,
	open list <linux-kernel@vger.kernel.org>,
	stable@vger.kernel.org,
	"open list:KERNEL VIRTUAL MACHINE FOR ARM64 \(KVM/arm64\)"
	<kvmarm@lists.cs.columbia.edu>, Mark Brown <broonie@kernel.org>,
	Sami Tolvanen <samitolvanen@google.com>,
	Marc Zyngier <maz@kernel.org>,
	Kristina Martsenko <kristina.martsenko@arm.com>,
	Will Deacon <will@kernel.org>, Ard Biesheuvel <ardb@kernel.org>,
	linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH stable v4.9 v2] arm64: entry: Place an SB sequence following an ERET instruction
Date: Mon, 20 Jul 2020 15:04:11 +0200	[thread overview]
Message-ID: <20200720130411.GB494210@kroah.com> (raw)
In-Reply-To: <20200709195034.15185-1-f.fainelli@gmail.com>

On Thu, Jul 09, 2020 at 12:50:23PM -0700, Florian Fainelli wrote:
> From: Will Deacon <will.deacon@arm.com>
> 
> commit 679db70801da9fda91d26caf13bf5b5ccc74e8e8 upstream
> 
> Some CPUs can speculate past an ERET instruction and potentially perform
> speculative accesses to memory before processing the exception return.
> Since the register state is often controlled by a lower privilege level
> at the point of an ERET, this could potentially be used as part of a
> side-channel attack.
> 
> This patch emits an SB sequence after each ERET so that speculation is
> held up on exception return.
> 
> Signed-off-by: Will Deacon <will.deacon@arm.com>
> [florian: Adjust hyp-entry.S to account for the label
>  added change to hyp/entry.S]
> Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
> ---
> Changes in v2:
> 
> - added missing hunk in hyp/entry.S per Will's feedback

What about 4.19.y and 4.14.y trees?  I can't take something for 4.9.y
and then have a regression if someone moves to a newer release, right?

thanks,

greg k-h
_______________________________________________
kvmarm mailing list
kvmarm@lists.cs.columbia.edu
https://lists.cs.columbia.edu/mailman/listinfo/kvmarm

  parent reply	other threads:[~2020-07-20 13:04 UTC|newest]

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-07-09 19:50 [PATCH stable v4.9 v2] arm64: entry: Place an SB sequence following an ERET instruction Florian Fainelli
2020-07-11  0:28 ` Sasha Levin
2020-07-20 13:04 ` Greg KH [this message]
2020-07-20 18:26   ` Florian Fainelli
2020-08-06 20:00     ` Florian Fainelli
2020-08-07 13:14       ` Greg KH
2020-08-07 18:17         ` Florian Fainelli
2020-08-13 20:52           ` Florian Fainelli
2020-08-21 16:03         ` Will Deacon
2020-08-21 17:16           ` Florian Fainelli
2020-08-24 16:32             ` Will Deacon
2020-08-24 16:42               ` Florian Fainelli

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=20200720130411.GB494210@kroah.com \
    --to=gregkh@linuxfoundation.org \
    --cc=ardb@kernel.org \
    --cc=broonie@kernel.org \
    --cc=catalin.marinas@arm.com \
    --cc=f.fainelli@gmail.com \
    --cc=kristina.martsenko@arm.com \
    --cc=kvmarm@lists.cs.columbia.edu \
    --cc=linux-arm-kernel@lists.infradead.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=maskray@google.com \
    --cc=maz@kernel.org \
    --cc=ndesaulniers@google.com \
    --cc=samitolvanen@google.com \
    --cc=stable@vger.kernel.org \
    --cc=will.deacon@arm.com \
    --cc=will@kernel.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).