system/qdev: Remove pointless NULL check in qdev_device_add_from_qdict

Coverity reported a unnecessary NULL check:

  qemu/system/qdev-monitor.c: 720 in qdev_device_add_from_qdict()
  683     /* create device */
  684     dev = qdev_new(driver);
  ...
  719     err_del_dev:
  >>>     CID 1590192:  Null pointer dereferences  (REVERSE_INULL)
  >>>     Null-checking "dev" suggests that it may be null, but it has already been dereferenced on all paths leading to the check.
  720         if (dev) {
  721             object_unparent(OBJECT(dev));
  722             object_unref(OBJECT(dev));
  723         }
  724         return NULL;
  725     }

Indeed, unlike qdev_try_new() which can return NULL,
qdev_new() always returns a heap pointer (or aborts).

Remove the unnecessary assignment and check.

Fixes: f3a85056569 ("qdev/qbus: add hidden device support")
Resolves: Coverity CID 1590192 (Null pointer dereferences)
Suggested-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

diff --git a/system/qdev-monitor.c b/system/qdev-monitor.c
index 5588ed2047d9e93bdaeebc057aa22dcd232e3c7f..2ac92d0a076cbeb3598a577bedc2adbe45fa93a6 100644 (file)
--- a/system/qdev-monitor.c
+++ b/system/qdev-monitor.c
@@ -628,7 +628,7 @@ DeviceState *qdev_device_add_from_qdict(const QDict *opts,
     DeviceClass *dc;
     const char *driver, *path;
     char *id;
-    DeviceState *dev = NULL;
+    DeviceState *dev;
     BusState *bus = NULL;
     QDict *properties;
 
@@ -717,10 +717,9 @@ DeviceState *qdev_device_add_from_qdict(const QDict *opts,
     return dev;
 
 err_del_dev:
-    if (dev) {
-        object_unparent(OBJECT(dev));
-        object_unref(OBJECT(dev));
-    }
+    object_unparent(OBJECT(dev));
+    object_unref(OBJECT(dev));
+
     return NULL;
 }