This is a note to let you know that I've just added the patch titled
KVM: s390: don't use current->thread.fpu.* when accessing registers
to the 4.7-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
kvm-s390-don-t-use-current-thread.fpu.-when-accessing-registers.patch
and it can be found in the queue-4.7 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From a7d4b8f2565ad0dfdff9a222d1d87990c73b36e8 Mon Sep 17 00:00:00 2001
From: David Hildenbrand <dahi@xxxxxxxxxxxxxxxxxx>
Date: Tue, 16 Aug 2016 14:38:24 +0200
Subject: KVM: s390: don't use current->thread.fpu.* when accessing registers
From: David Hildenbrand <dahi@xxxxxxxxxxxxxxxxxx>
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
current->thread.
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 <haoqf@xxxxxxxxxxxxxxxxxx>
Signed-off-by: David Hildenbrand <dahi@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Christian Borntraeger <borntraeger@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
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);
else
- 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 */
save_fpu_regs();
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);
else
- 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;
}
Patches currently in stable-queue which might be from dahi@xxxxxxxxxxxxxxxxxx are
queue-4.7/kvm-s390-don-t-use-current-thread.fpu.-when-accessing-registers.patch
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