target-i386: Fix X86CPU error handling

Error **errp argument is not for emitting warnings, it means an error
has occurred and the caller should not make any assumptions about the
state of other return values (unless otherwise documented).

Therefore cpu_x86_create() must unref the new X86CPU itself, and
pc_new_cpu() must check for an Error rather than NULL return value.

While at it, clean up a superfluous NULL check.

Reported-by: Jan Kiszka <jan.kiszka@siemens.com>
Cc: qemu-stable@nongnu.org
Cc: Igor Mammedov <imammedo@redhat.com>
Signed-off-by: Andreas Färber <afaerber@suse.de>

2 files changed, 11 insertions, 8 deletions

diff --git a/hw/i386/pc.c b/hw/i386/pc.c
index a2b9d889d..6a0b04278 100644
--- a/hw/i386/pc.c
+++ b/hw/i386/pc.c
@@ -912,20 +912,19 @@ static X86CPU *pc_new_cpu(const char *cpu_model, int64_t apic_id,
     X86CPU *cpu;
     Error *local_err = NULL;
 
-    cpu = cpu_x86_create(cpu_model, icc_bridge, errp);
-    if (!cpu) {
-        return cpu;
+    cpu = cpu_x86_create(cpu_model, icc_bridge, &local_err);
+    if (local_err != NULL) {
+        error_propagate(errp, local_err);
+        return NULL;
     }
 
     object_property_set_int(OBJECT(cpu), apic_id, "apic-id", &local_err);
     object_property_set_bool(OBJECT(cpu), true, "realized", &local_err);
 
     if (local_err) {
-        if (cpu != NULL) {
-            object_unref(OBJECT(cpu));
-            cpu = NULL;
-        }
         error_propagate(errp, local_err);
+        object_unref(OBJECT(cpu));
+        cpu = NULL;
     }
     return cpu;
 }
diff --git a/target-i386/cpu.c b/target-i386/cpu.c
index 71ab91531..2efbeca8b 100644
--- a/target-i386/cpu.c
+++ b/target-i386/cpu.c
@@ -1824,7 +1824,11 @@ X86CPU *cpu_x86_create(const char *cpu_model, DeviceState *icc_bridge,
     }
 
 out:
-    error_propagate(errp, error);
+    if (error != NULL) {
+        error_propagate(errp, error);
+        object_unref(OBJECT(cpu));
+        cpu = NULL;
+    }
     g_strfreev(model_pieces);
     return cpu;
 }