Re: [PATCH] x86,perf: Disable intel_bts when PTI

From: Thomas Gleixner
Date: Sun Jan 14 2018 - 05:52:13 EST


On Sun, 14 Jan 2018, 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 <alexander.shishkin@xxxxxxxxxxxxxxx>
> > Reported-by: Vince Weaver <vincent.weaver@xxxxxxxxx>
> > Reported-by: Robert ÅwiÄcki <robert@xxxxxxxxxxx>
> > Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
>
> Can you add a:
> Cc: stable <stable@xxxxxxxxxxxxxxx>
> please?

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