4.7-stable review patch.  If anyone has any objections, please let me know.


From: David Hildenbrand <d...@linux.vnet.ibm.com>

commit a7d4b8f2565ad0dfdff9a222d1d87990c73b36e8 upstream.

As the meaning of these variables and pointers seems to change more
frequently, let's directly access our save area, instead of going via

Right now, this is broken for set/get_fpu. They simply overwrite the
host registers, as the pointers to the current save area were turned
into the static host save area.

Fixes: 3f6813b9a5e0 ("s390/fpu: allocate 'struct fpu' with the task_struct")
Reported-by: Hao QingFeng <ha...@linux.vnet.ibm.com>
Signed-off-by: David Hildenbrand <d...@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntrae...@de.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org>

 arch/s390/kvm/kvm-s390.c |   10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

--- a/arch/s390/kvm/kvm-s390.c
+++ b/arch/s390/kvm/kvm-s390.c
@@ -1951,9 +1951,10 @@ int kvm_arch_vcpu_ioctl_set_fpu(struct k
                return -EINVAL;
        current->thread.fpu.fpc = fpu->fpc;
        if (MACHINE_HAS_VX)
-               convert_fp_to_vx(current->thread.fpu.vxrs, (freg_t *)fpu->fprs);
+               convert_fp_to_vx((__vector128 *) vcpu->run->s.regs.vrs,
+                                (freg_t *) fpu->fprs);
-               memcpy(current->thread.fpu.fprs, &fpu->fprs, sizeof(fpu->fprs));
+               memcpy(vcpu->run->s.regs.fprs, &fpu->fprs, sizeof(fpu->fprs));
        return 0;
@@ -1962,9 +1963,10 @@ int kvm_arch_vcpu_ioctl_get_fpu(struct k
        /* make sure we have the latest values */
        if (MACHINE_HAS_VX)
-               convert_vx_to_fp((freg_t *)fpu->fprs, current->thread.fpu.vxrs);
+               convert_vx_to_fp((freg_t *) fpu->fprs,
+                                (__vector128 *) vcpu->run->s.regs.vrs);
-               memcpy(fpu->fprs, current->thread.fpu.fprs, sizeof(fpu->fprs));
+               memcpy(fpu->fprs, vcpu->run->s.regs.fprs, sizeof(fpu->fprs));
        fpu->fpc = current->thread.fpu.fpc;
        return 0;

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