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s390/kvm,tprot: use new gmap_translate() function 

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@de.ibm.com>
Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
This commit is contained in:
Heiko Carstens 2013-03-05 13:14:42 +01:00 committed by Marcelo Tosatti
parent 9e0fdb4145
commit 59a1fa2d80
1 changed files with 9 additions and 12 deletions
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21
arch/s390/kvm/priv.c
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@ -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(&current->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(&current->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(&current->mm->mmap_sem);
return 0;
out_inject:
up_read(&current->mm->mmap_sem);
return kvm_s390_inject_program_int(vcpu, PGM_ADDRESSING);
}
int kvm_s390_handle_e5(struct kvm_vcpu *vcpu)