[Qemu-stable] [PATCH 49/56] target-i386: Fix X86CPU error handling

[Michael Roth]

From: Andreas Färber <address@hidden>

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 <address@hidden>
Cc: address@hidden
Cc: Igor Mammedov <address@hidden>
Signed-off-by: Andreas Färber <address@hidden>
(cherry picked from commit cd7b87ffe9b6b7b0089ec8c71555f3b942bc6daf)

Signed-off-by: Michael Roth <address@hidden>
---
 hw/i386/pc.c      |   13 ++++++-------
 target-i386/cpu.c |    6 +++++-
 2 files changed, 11 insertions(+), 8 deletions(-)

diff --git a/hw/i386/pc.c b/hw/i386/pc.c
index e2c44f8..a7ecfb0 100644
--- a/hw/i386/pc.c
+++ b/hw/i386/pc.c
@@ -902,20 +902,19 @@ 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 ae8e682..cdae1ce 100644
--- a/target-i386/cpu.c
+++ b/target-i386/cpu.c
@@ -1820,7 +1820,11 @@ 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;
 }
-- 
1.7.9.5