[lkml]   [2018]   [Jan]   [14]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
SubjectRe: [PATCH] x86,perf: Disable intel_bts when PTI

* 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



 \ /
  Last update: 2018-01-14 23:27    [W:0.047 / U:0.908 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site