KVM: s390: Fix user triggerable bug in dead code
commit 614a80e474b227cace52fd6e3c790554db8a396e upstream.
In the early days, we had some special handling for the
KVM_EXIT_S390_SIEIC exit, but this was gone in 2009 with commit
d7b0b5eb3000 (KVM: s390: Make psw available on all exits, not
just a subset).
Now this switch statement is just a sanity check for userspace
not messing with the kvm_run structure. Unfortunately, this
allows userspace to trigger a kernel BUG. Let's just remove
this switch statement.
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Reviewed-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
[lizf: Backported to 3.4:
- adjust context
- no KVM_EXIT_S390_TSCH and KVM_EXIT_DEBUG in 3.4]
Signed-off-by: Zefan Li <lizefan@huawei.com>
diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
index 53c973e..0f250d1 100644
--- a/arch/s390/kvm/kvm-s390.c
+++ b/arch/s390/kvm/kvm-s390.c
@@ -566,17 +566,6 @@
BUG_ON(vcpu->kvm->arch.float_int.local_int[vcpu->vcpu_id] == NULL);
- switch (kvm_run->exit_reason) {
- case KVM_EXIT_S390_SIEIC:
- case KVM_EXIT_UNKNOWN:
- case KVM_EXIT_INTR:
- case KVM_EXIT_S390_RESET:
- case KVM_EXIT_S390_UCONTROL:
- break;
- default:
- BUG();
- }
-
vcpu->arch.sie_block->gpsw.mask = kvm_run->psw_mask;
vcpu->arch.sie_block->gpsw.addr = kvm_run->psw_addr;
if (kvm_run->kvm_dirty_regs & KVM_SYNC_PREFIX) {