From: Heiko Carstens <heiko.carstens@xxxxxxxxxx>
When out-of-memory the tprot code incorrectly injected a program check
for the guest which reported an addressing exception even if the guest
address was valid.
Let's use the new gmap_translate() which translates a guest address to
a user space address whithout the chance of running into an out-of-memory
situation.
Also make it more explicit that for -EFAULT we won't find a vma.
Signed-off-by: Heiko Carstens <heiko.carstens@xxxxxxxxxx>
Reviewed-by: Christian Borntraeger <borntraeger@xxxxxxxxxx>
Signed-off-by: Martin Schwidefsky <schwidefsky@xxxxxxxxxx>
Signed-off-by: Christian Borntraeger <borntraeger@xxxxxxxxxx>
---
arch/s390/kvm/priv.c | 21 +++++++++------------
1 file changed, 9 insertions(+), 12 deletions(-)
diff --git a/arch/s390/kvm/priv.c b/arch/s390/kvm/priv.c
index 0ef9894..75ad91e 100644
--- a/arch/s390/kvm/priv.c
+++ b/arch/s390/kvm/priv.c
@@ -575,20 +575,13 @@ static int handle_tprot(struct kvm_vcpu *vcpu)
if (vcpu->arch.sie_block->gpsw.mask & PSW_MASK_DAT)
return -EOPNOTSUPP;
-
- /* we must resolve the address without holding the mmap semaphore.
- * This is ok since the userspace hypervisor is not supposed to change
- * the mapping while the guest queries the memory. Otherwise the guest
- * might crash or get wrong info anyway. */
- user_address = (unsigned long) __guestaddr_to_user(vcpu, address1);
-
down_read(¤t->mm->mmap_sem);
+ user_address = __gmap_translate(address1, vcpu->arch.gmap);
+ if (IS_ERR_VALUE(user_address))
+ goto out_inject;
vma = find_vma(current->mm, user_address);
- if (!vma) {
- up_read(¤t->mm->mmap_sem);
- return kvm_s390_inject_program_int(vcpu, PGM_ADDRESSING);
- }
-
+ if (!vma)
+ goto out_inject;
vcpu->arch.sie_block->gpsw.mask &= ~(3ul << 44);
if (!(vma->vm_flags & VM_WRITE) && (vma->vm_flags & VM_READ))
vcpu->arch.sie_block->gpsw.mask |= (1ul << 44);
@@ -597,6 +590,10 @@ static int handle_tprot(struct kvm_vcpu *vcpu)
up_read(¤t->mm->mmap_sem);
return 0;
+
+out_inject:
+ up_read(¤t->mm->mmap_sem);
+ return kvm_s390_inject_program_int(vcpu, PGM_ADDRESSING);
}
int kvm_s390_handle_e5(struct kvm_vcpu *vcpu)
--
1.8.0.1
--
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