Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm
Pull KVM fixes from Radim Krčmář:
"Fix races and a potential use after free in the s390 cmma migration
code"
* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
KVM: s390: add proper locking for CMMA migration bitmap
+11
-7
+11
-7
arch/s390/kvm/kvm-s390.c
+11
-7
arch/s390/kvm/kvm-s390.c
···
769
769
770
770
/*
771
771
* Must be called with kvm->srcu held to avoid races on memslots, and with
772
-
* kvm->lock to avoid races with ourselves and kvm_s390_vm_stop_migration.
772
+
* kvm->slots_lock to avoid races with ourselves and kvm_s390_vm_stop_migration.
773
773
*/
774
774
static int kvm_s390_vm_start_migration(struct kvm *kvm)
775
775
{
···
825
825
}
826
826
827
827
/*
828
-
* Must be called with kvm->lock to avoid races with ourselves and
828
+
* Must be called with kvm->slots_lock to avoid races with ourselves and
829
829
* kvm_s390_vm_start_migration.
830
830
*/
831
831
static int kvm_s390_vm_stop_migration(struct kvm *kvm)
···
840
840
841
841
if (kvm->arch.use_cmma) {
842
842
kvm_s390_sync_request_broadcast(kvm, KVM_REQ_STOP_MIGRATION);
843
+
/* We have to wait for the essa emulation to finish */
844
+
synchronize_srcu(&kvm->srcu);
843
845
vfree(mgs->pgste_bitmap);
844
846
}
845
847
kfree(mgs);
···
851
849
static int kvm_s390_vm_set_migration(struct kvm *kvm,
852
850
struct kvm_device_attr *attr)
853
851
{
854
-
int idx, res = -ENXIO;
852
+
int res = -ENXIO;
855
853
856
-
mutex_lock(&kvm->lock);
854
+
mutex_lock(&kvm->slots_lock);
857
855
switch (attr->attr) {
858
856
case KVM_S390_VM_MIGRATION_START:
859
-
idx = srcu_read_lock(&kvm->srcu);
860
857
res = kvm_s390_vm_start_migration(kvm);
861
-
srcu_read_unlock(&kvm->srcu, idx);
862
858
break;
863
859
case KVM_S390_VM_MIGRATION_STOP:
864
860
res = kvm_s390_vm_stop_migration(kvm);
···
864
864
default:
865
865
break;
866
866
}
867
-
mutex_unlock(&kvm->lock);
867
+
mutex_unlock(&kvm->slots_lock);
868
868
869
869
return res;
870
870
}
···
1754
1754
r = -EFAULT;
1755
1755
if (copy_from_user(&args, argp, sizeof(args)))
1756
1756
break;
1757
+
mutex_lock(&kvm->slots_lock);
1757
1758
r = kvm_s390_get_cmma_bits(kvm, &args);
1759
+
mutex_unlock(&kvm->slots_lock);
1758
1760
if (!r) {
1759
1761
r = copy_to_user(argp, &args, sizeof(args));
1760
1762
if (r)
···
1770
1768
r = -EFAULT;
1771
1769
if (copy_from_user(&args, argp, sizeof(args)))
1772
1770
break;
1771
+
mutex_lock(&kvm->slots_lock);
1773
1772
r = kvm_s390_set_cmma_bits(kvm, &args);
1773
+
mutex_unlock(&kvm->slots_lock);
1774
1774
break;
1775
1775
}
1776
1776
default: