Andy Lutomirski e824880110 x86_64/entry/xen: Do not invoke espfix64 on Xen ...

commit 7209a75d20 upstream.

This moves the espfix64 logic into native_iret.  To make this work,
it gets rid of the native patch for INTERRUPT_RETURN:
INTERRUPT_RETURN on native kernels is now 'jmp native_iret'.

This changes the 16-bit SS behavior on Xen from OOPSing to leaking
some bits of the Xen hypervisor's RSP (I think).

[ hpa: this is a nonzero cost on native, but probably not enough to
  measure. Xen needs to fix this in their own code, probably doing
  something equivalent to espfix64. ]

Signed-off-by: Andy Lutomirski <luto@amacapital.net>
Link: http://lkml.kernel.org/r/7b8f1d8ef6597cb16ae004a43c56980a7de3cf94.1406129132.git.luto@amacapital.net
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

2014-08-07 14:30:26 -07:00

..

asm

x86_64/entry/xen: Do not invoke espfix64 on Xen

2014-08-07 14:30:26 -07:00

uapi/asm

x86, cpu, amd: Add workaround for family 16h, erratum 793

2014-02-06 11:08:18 -08:00