[PATCH AUTOSEL 4.9 28/91] KVM: s390: unregister debug feature on failing arch init

[Sasha Levin]

From: Michael Mueller <mimu@xxxxxxxxxxxxx>

[ Upstream commit 308c3e6673b012beecb96ef04cc65f4a0e7cdd99 ]

Make sure the debug feature and its allocated resources get
released upon unsuccessful architecture initialization.

A related indication of the issue will be reported as kernel
message.

Signed-off-by: Michael Mueller <mimu@xxxxxxxxxxxxx>
Reviewed-by: Cornelia Huck <cohuck@xxxxxxxxxx>
Reviewed-by: Pierre Morel <pmorel@xxxxxxxxxxxxx>
Reviewed-by: David Hildenbrand <david@xxxxxxxxxx>
Message-Id: <20181130143215.69496-2-mimu@xxxxxxxxxxxxx>
Signed-off-by: Christian Borntraeger <borntraeger@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 arch/s390/kvm/kvm-s390.c | 17 ++++++++++++++---
 1 file changed, 14 insertions(+), 3 deletions(-)

diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
index 37c254677ccda..d8fd2eadcda7f 100644
--- a/arch/s390/kvm/kvm-s390.c
+++ b/arch/s390/kvm/kvm-s390.c
@@ -319,19 +319,30 @@ static void kvm_s390_cpu_feat_init(void)
 
 int kvm_arch_init(void *opaque)
 {
+	int rc;
+
 	kvm_s390_dbf = debug_register("kvm-trace", 32, 1, 7 * sizeof(long));
 	if (!kvm_s390_dbf)
 		return -ENOMEM;
 
 	if (debug_register_view(kvm_s390_dbf, &debug_sprintf_view)) {
-		debug_unregister(kvm_s390_dbf);
-		return -ENOMEM;
+		rc = -ENOMEM;
+		goto out_debug_unreg;
 	}
 
 	kvm_s390_cpu_feat_init();
 
 	/* Register floating interrupt controller interface. */
-	return kvm_register_device_ops(&kvm_flic_ops, KVM_DEV_TYPE_FLIC);
+	rc = kvm_register_device_ops(&kvm_flic_ops, KVM_DEV_TYPE_FLIC);
+	if (rc) {
+		pr_err("Failed to register FLIC rc=%d\n", rc);
+		goto out_debug_unreg;
+	}
+	return 0;
+
+out_debug_unreg:
+	debug_unregister(kvm_s390_dbf);
+	return rc;
 }
 
 void kvm_arch_exit(void)
-- 
2.20.1