Re: [PATCH v2 00/18] arm64: Unmap the kernel whilst running in userspace (KAISER)

From: Will Deacon
Date: Fri Dec 01 2017 - 12:50:27 EST


Hi Mark,

On Fri, Dec 01, 2017 at 02:04:06PM +0000, Mark Rutland wrote:
> On Thu, Nov 30, 2017 at 04:39:28PM +0000, Will Deacon wrote:
> > Hi again,
> >
> > This is version two of the patches previously posted here:
> >
> > http://lists.infradead.org/pipermail/linux-arm-kernel/2017-November/542751.html
> >
> > Changes since v1 include:
> >
> > * Based on v4.15-rc1
> > * Trampoline moved into FIXMAP area
> > * Explicit static key replaced by cpu cap
> > * Disable SPE for userspace profiling if kernel unmapped at EL0
> > * Changed polarity of cpu feature to match config option
> > * Changed command-line option so we can force on in future if necessary
> > * Changed Falkor workaround to invalidate different page within 2MB region
> > * Reworked alternative sequences in entry.S, since the NOP slides with
> > kaiser=off were measurable
>
> This generally looks good to me.
>
> For patches patches 1-10, 13-15, and 17, feel free to add:
>
> Reviewed-by: Mark Rutland <mark.rutland@xxxxxxx>

Thanks for going through this. Do you have any ideas about what we could
rename the command-line option to? I'll get us started:

- kaiser=
- hidekernel=
- unmapkernel=
- hardenkaslr=
- swuan=

...

Will