x86/mm/kmmio: Make the tracer robust against L1TF
authorAndi Kleen <ak@linux.intel.com>
Tue, 7 Aug 2018 22:09:38 +0000 (15:09 -0700)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Wed, 15 Aug 2018 16:14:54 +0000 (18:14 +0200)
commite79d049743f1466084df5708cd0e052b0d586548
tree7c63f0371ae559f287b4b2fa5c01449c36613ef6
parent7e464373357dd6ff33a1a7373d5e596ed1dbb219
x86/mm/kmmio: Make the tracer robust against L1TF

commit 1063711b57393c1999248cccb57bebfaf16739e7 upstream

The mmio tracer sets io mapping PTEs and PMDs to non present when enabled
without inverting the address bits, which makes the PTE entry vulnerable
for L1TF.

Make it use the right low level macros to actually invert the address bits
to protect against L1TF.

In principle this could be avoided because MMIO tracing is not likely to be
enabled on production machines, but the fix is straigt forward and for
consistency sake it's better to get rid of the open coded PTE manipulation.

Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
arch/x86/mm/kmmio.c