LKML Archive on
 help / color / Atom feed
From: Ingo Molnar <>
To: Greg KH <>
Cc: Peter Zijlstra <>,
	Thomas Gleixner <>,, Vince Weaver <>,,,,,
	Alexander Shishkin <>
Subject: Re: [PATCH] x86,perf: Disable intel_bts when PTI
Date: Sun, 14 Jan 2018 13:54:44 +0100
Message-ID: <> (raw)
In-Reply-To: <>

* Greg KH <> wrote:

> On Sun, Jan 14, 2018 at 11:27:13AM +0100, Peter Zijlstra wrote:
> > 
> > The intel_bts driver does not use the 'normal' BTS buffer we allocated
> > space for in the cpu_entry_area but instead uses the memory allocated
> > for the perf AUX buffer.
> > 
> > This obviously comes apart when using PTI because then the kernel
> > mapping; which includes that AUX buffer memory; disappears.
> > 
> > For now disable this driver when PTI is enabled, we'll try and sort
> > something out later.
> > 
> > Cc: Alexander Shishkin <>
> > Reported-by: Vince Weaver <>
> > Reported-by: Robert Święcki <>
> > Signed-off-by: Peter Zijlstra (Intel) <>
> Can you add a:
> 	Cc: stable <>
> please?

Note that these fixes are all going into tip:x86/pti, which is still a backporting 
friendly linear set of commits that should all be backported.

So once 99a9dc98ba52 goes upstream, all of v4.14..99a9dc98ba52 the remaining bits 
can go to -stable as well.

Will keep you updated about the latest status periodically, right now the latest 
that is already upstream is:

  de791821c295: x86/pti: Rename BUG_CPU_INSECURE to BUG_CPU_MELTDOWN

i.e. all 194 commits in the v4.14..de791821c295 range should be queued up for 
-stable. (And most of them already are.)

There are 28 new commits in tip:x86/pti that will (hopefully) go upstream later 



  parent reply index

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-01-14 10:27 Peter Zijlstra
2018-01-14 10:46 ` [tip:x86/pti] " tip-bot for Peter Zijlstra
2018-01-14 10:50 ` [PATCH] " Greg KH
2018-01-14 10:52   ` Thomas Gleixner
2018-01-14 12:54   ` Ingo Molnar [this message]
2018-01-14 13:27     ` Greg KH

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:

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \ \ \ \ \ \ \ \ \ \ \ \ \

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

LKML Archive on

Archives are clonable:
	git clone --mirror lkml/git/0.git
	git clone --mirror lkml/git/1.git
	git clone --mirror lkml/git/2.git
	git clone --mirror lkml/git/3.git
	git clone --mirror lkml/git/4.git
	git clone --mirror lkml/git/5.git
	git clone --mirror lkml/git/6.git
	git clone --mirror lkml/git/7.git
	git clone --mirror lkml/git/8.git
	git clone --mirror lkml/git/9.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 lkml lkml/ \
	public-inbox-index lkml

Example config snippet for mirrors

Newsgroup available over NNTP:

AGPL code for this site: git clone