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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 15:42:11 +0000 (17:42 +0200)
commit6b06f36f07e2c91ad0126f17d0fc8f933c827da8
treea9540a4018bf801f385642d99e0162bbe5e35542
parent02ff2769edbce2261e981effbc3c4b98fae4faf0
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: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
arch/x86/mm/kmmio.c