Since the @def is consumed by the assignment function, let's pass by
reference instead of value and really consume it.

Signed-off-by: John Ferlan <jferlan@redhat.com>
---
 src/conf/virnodedeviceobj.c        | 8 ++++----
 src/conf/virnodedeviceobj.h        | 2 +-
 src/node_device/node_device_hal.c  | 2 +-
 src/node_device/node_device_udev.c | 8 +++-----
 src/test/test_driver.c             | 5 ++---
 5 files changed, 11 insertions(+), 14 deletions(-)

diff --git a/src/conf/virnodedeviceobj.c b/src/conf/virnodedeviceobj.c
index a7e51ef..1648b33 100644
--- a/src/conf/virnodedeviceobj.c
+++ b/src/conf/virnodedeviceobj.c
@@ -268,13 +268,13 @@ virNodeDeviceObjListFree(virNodeDeviceObjListPtr devs)
 
 virNodeDeviceObjPtr
 virNodeDeviceObjAssignDef(virNodeDeviceObjListPtr devs,
-                          virNodeDeviceDefPtr def)
+                          virNodeDeviceDefPtr *def)
 {
     virNodeDeviceObjPtr obj;
 
-    if ((obj = virNodeDeviceObjFindByName(devs, def->name))) {
+    if ((obj = virNodeDeviceObjFindByName(devs, (*def)->name))) {
         virNodeDeviceDefFree(obj->def);
-        obj->def = def;
+        VIR_STEAL_PTR(obj->def, *def);
         return obj;
     }
 
@@ -294,7 +294,7 @@ virNodeDeviceObjAssignDef(virNodeDeviceObjListPtr devs,
         virNodeDeviceObjFree(obj);
         return NULL;
     }
-    obj->def = def;
+    VIR_STEAL_PTR(obj->def, *def);
 
     return obj;
 
diff --git a/src/conf/virnodedeviceobj.h b/src/conf/virnodedeviceobj.h
index 135a424..49c28e7 100644
--- a/src/conf/virnodedeviceobj.h
+++ b/src/conf/virnodedeviceobj.h
@@ -53,7 +53,7 @@ virNodeDeviceObjFindBySysfsPath(virNodeDeviceObjListPtr devs,
 
 virNodeDeviceObjPtr
 virNodeDeviceObjAssignDef(virNodeDeviceObjListPtr devs,
-                          virNodeDeviceDefPtr def);
+                          virNodeDeviceDefPtr *def);
 
 void
 virNodeDeviceObjRemove(virNodeDeviceObjListPtr devs,
diff --git a/src/node_device/node_device_hal.c b/src/node_device/node_device_hal.c
index e9031ea..2d996a9 100644
--- a/src/node_device/node_device_hal.c
+++ b/src/node_device/node_device_hal.c
@@ -482,7 +482,7 @@ dev_create(const char *udi)
     /* Some devices don't have a path in sysfs, so ignore failure */
     (void)get_str_prop(ctx, udi, "linux.sysfs_path", &devicePath);
 
-    if (!(obj = virNodeDeviceObjAssignDef(&driver->devs, def))) {
+    if (!(obj = virNodeDeviceObjAssignDef(&driver->devs, &def))) {
         VIR_FREE(devicePath);
         goto failure;
     }
diff --git a/src/node_device/node_device_udev.c b/src/node_device/node_device_udev.c
index 83a8fcc..0250aab 100644
--- a/src/node_device/node_device_udev.c
+++ b/src/node_device/node_device_udev.c
@@ -1395,7 +1395,7 @@ udevAddOneDevice(struct udev_device *device)
 
     /* If this is a device change, the old definition will be freed
      * and the current definition will take its place. */
-    if (!(obj = virNodeDeviceObjAssignDef(&driver->devs, def)))
+    if (!(obj = virNodeDeviceObjAssignDef(&driver->devs, &def)))
         goto cleanup;
     objdef = virNodeDeviceObjGetDef(obj);
 
@@ -1685,8 +1685,7 @@ udevSetupSystemDev(void)
     udevGetDMIData(&def->caps->data.system);
 #endif
 
-    obj = virNodeDeviceObjAssignDef(&driver->devs, def);
-    if (obj == NULL)
+    if (!(obj = virNodeDeviceObjAssignDef(&driver->devs, &def)))
         goto cleanup;
 
     virNodeDeviceObjUnlock(obj);
@@ -1694,8 +1693,7 @@ udevSetupSystemDev(void)
     ret = 0;
 
  cleanup:
-    if (ret == -1)
-        virNodeDeviceDefFree(def);
+    virNodeDeviceDefFree(def);
 
     return ret;
 }
diff --git a/src/test/test_driver.c b/src/test/test_driver.c
index 206fdf9..84ff1de 100644
--- a/src/test/test_driver.c
+++ b/src/test/test_driver.c
@@ -1168,7 +1168,7 @@ testParseNodedevs(testDriverPtr privconn,
         if (!def)
             goto error;
 
-        if (!(obj = virNodeDeviceObjAssignDef(&privconn->devs, def))) {
+        if (!(obj = virNodeDeviceObjAssignDef(&privconn->devs, &def))) {
             virNodeDeviceDefFree(def);
             goto error;
         }
@@ -5491,9 +5491,8 @@ testNodeDeviceMockCreateVport(testDriverPtr driver,
         caps = caps->next;
     }
 
-    if (!(obj = virNodeDeviceObjAssignDef(&driver->devs, def)))
+    if (!(obj = virNodeDeviceObjAssignDef(&driver->devs, &def)))
         goto cleanup;
-    def = NULL;
     objdef = virNodeDeviceObjGetDef(obj);
 
     event = virNodeDeviceEventLifecycleNew(objdef->name,
-- 
2.9.4

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On Thu, May 25, 2017 at 15:57:10 -0400, John Ferlan wrote:
> Since the @def is consumed by the assignment function, let's pass by
> reference instead of value and really consume it.
> 
> Signed-off-by: John Ferlan <jferlan@redhat.com>
> ---
>  src/conf/virnodedeviceobj.c        | 8 ++++----
>  src/conf/virnodedeviceobj.h        | 2 +-
>  src/node_device/node_device_hal.c  | 2 +-
>  src/node_device/node_device_udev.c | 8 +++-----
>  src/test/test_driver.c             | 5 ++---
>  5 files changed, 11 insertions(+), 14 deletions(-)
> 
> diff --git a/src/conf/virnodedeviceobj.c b/src/conf/virnodedeviceobj.c
> index a7e51ef..1648b33 100644
> --- a/src/conf/virnodedeviceobj.c
> +++ b/src/conf/virnodedeviceobj.c
> @@ -268,13 +268,13 @@ virNodeDeviceObjListFree(virNodeDeviceObjListPtr devs)
>  
>  virNodeDeviceObjPtr
>  virNodeDeviceObjAssignDef(virNodeDeviceObjListPtr devs,
> -                          virNodeDeviceDefPtr def)
> +                          virNodeDeviceDefPtr *def)

I don't really like this. You can documment that this function either
consumes def always or only on success and the callers can free the
pointer. Passing the pointer to a pointer just to clear it in some cases
is overcomplicating stuff.
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On 05/26/2017 08:12 AM, Peter Krempa wrote:
> On Thu, May 25, 2017 at 15:57:10 -0400, John Ferlan wrote:
>> Since the @def is consumed by the assignment function, let's pass by
>> reference instead of value and really consume it.
>>
>> Signed-off-by: John Ferlan <jferlan@redhat.com>
>> ---
>>  src/conf/virnodedeviceobj.c        | 8 ++++----
>>  src/conf/virnodedeviceobj.h        | 2 +-
>>  src/node_device/node_device_hal.c  | 2 +-
>>  src/node_device/node_device_udev.c | 8 +++-----
>>  src/test/test_driver.c             | 5 ++---
>>  5 files changed, 11 insertions(+), 14 deletions(-)
>>
>> diff --git a/src/conf/virnodedeviceobj.c b/src/conf/virnodedeviceobj.c
>> index a7e51ef..1648b33 100644
>> --- a/src/conf/virnodedeviceobj.c
>> +++ b/src/conf/virnodedeviceobj.c
>> @@ -268,13 +268,13 @@ virNodeDeviceObjListFree(virNodeDeviceObjListPtr devs)
>>  
>>  virNodeDeviceObjPtr
>>  virNodeDeviceObjAssignDef(virNodeDeviceObjListPtr devs,
>> -                          virNodeDeviceDefPtr def)
>> +                          virNodeDeviceDefPtr *def)
> 
> I don't really like this. You can documment that this function either
> consumes def always or only on success and the callers can free the
> pointer. Passing the pointer to a pointer just to clear it in some cases
> is overcomplicating stuff.
> 

True, but I ran into in one case (I forget which one now) where the
assumption was that the @def wasn't consumed on a failure, but in
reality it had been.  The obj->def got assigned, then the attempt was
made to add the obj to the list which if it failed would call whatever
cleanup routine was there which free'd @obj->def and returned to the
caller with a failure which would attempt to free @def (again). My first
instinct was to just set obj->def = NULL prior to the cleanup, which
worked for a short time until obj->def was a "real" object and the
cleanup code didn't own obj any more.

So it's the long winded way of saying - I can drop this and the
following patch either be "more careful" as necessary or just claim at
some point in time that @def would be consumed on both success and
failure, which I think follows how virJSONValueObjectCreate eats the
"a:" arguments (and causes many false positives for Coverity).

John

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