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From: Markus Armbruster <armbru@redhat.com>
To: Paolo Bonzini <pbonzini@redhat.com>
Cc: "Daniel P. Berrangé" <berrange@redhat.com>,
	"Eduardo Habkost" <ehabkost@redhat.com>,
	"Juan Quintela" <quintela@redhat.com>,
	"Michael Roth" <mdroth@linux.vnet.ibm.com>,
	qemu-devel@nongnu.org,
	"Marc-André Lureau" <marcandre.lureau@redhat.com>,
	"Dr. David Alan Gilbert" <dgilbert@redhat.com>
Subject: Re: [PATCH for-5.0 3/3] object-add: don't create return value if failed
Date: Mon, 30 Mar 2020 16:48:59 +0200
Message-ID: <87wo71ucdg.fsf@dusky.pond.sub.org> (raw)
In-Reply-To: <c408ed09-3740-bc5d-2e39-318bb5beff3f@redhat.com> (Paolo Bonzini's message of "Thu, 26 Mar 2020 10:42:08 +0100")

Paolo Bonzini <pbonzini@redhat.com> writes:

> On 25/03/20 19:47, Marc-André Lureau wrote:
>> If object-add failed, no need to create a return value that may later
>> be leaked.
>> 
>> Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
>> ---
>>  qom/qom-qmp-cmds.c | 2 +-
>>  1 file changed, 1 insertion(+), 1 deletion(-)
>> 
>> diff --git a/qom/qom-qmp-cmds.c b/qom/qom-qmp-cmds.c
>> index 435193b036..6bd137ccbf 100644
>> --- a/qom/qom-qmp-cmds.c
>> +++ b/qom/qom-qmp-cmds.c
>> @@ -287,8 +287,8 @@ void qmp_object_add(QDict *qdict, QObject **ret_data, Error **errp)
>>      visit_free(v);
>>      if (obj) {
>>          object_unref(obj);
>> +        *ret_data = QOBJECT(qdict_new());
>>      }
>> -    *ret_data = QOBJECT(qdict_new());
>>  }
>>  
>>  void qmp_object_del(const char *id, Error **errp)
>> 
>
> It can be slightly simplified:
>
> ------------------- 8< ----------------------
> From: Paolo Bonzini <pbonzini@redhat.com>
> Subject: [PATCH] object-add: don't create return value if failed
>     
> No need to return an empty value from object-add (it would also leak
> if the command failed).  While at it, remove the "if" around object_unref
> since object_unref handles NULL arguments just fine.
>     
> Reported-by: Marc-André Lureau <marcandre.lureau@redhat.com>
> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
>
> diff --git a/qom/qom-qmp-cmds.c b/qom/qom-qmp-cmds.c
> index 435193b036..e47ebe8ed1 100644
> --- a/qom/qom-qmp-cmds.c
> +++ b/qom/qom-qmp-cmds.c
> @@ -285,10 +285,7 @@ void qmp_object_add(QDict *qdict, QObject **ret_data, Error **errp)
>      v = qobject_input_visitor_new(QOBJECT(qdict));
>      obj = user_creatable_add_type(type, id, qdict, v, errp);
>      visit_free(v);
> -    if (obj) {
> -        object_unref(obj);
> -    }
> -    *ret_data = QOBJECT(qdict_new());
> +    object_unref(obj);
>  }
>  
>  void qmp_object_del(const char *id, Error **errp)

Yes, that's better.

Reviewed-by: Markus Armbruster <armbru@redhat.com>

> I queued this patch and your other two.  Thanks,
>
> Paolo



      reply index

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-03-25 18:47 [PATCH for-5.0 0/3] Memory leak fixes Marc-André Lureau
2020-03-25 18:47 ` [PATCH for-5.0 1/3] migration: fix cleanup_bh leak on resume Marc-André Lureau
2020-03-26  2:40   ` Juan Quintela
2020-03-25 18:47 ` [PATCH for-5.0 2/3] qmp: fix leak on callbacks that return both value and error Marc-André Lureau
2020-03-30 14:59   ` Markus Armbruster
2020-03-25 18:47 ` [PATCH for-5.0 3/3] object-add: don't create return value if failed Marc-André Lureau
2020-03-25 20:43   ` Philippe Mathieu-Daudé
2020-03-26  9:42   ` Paolo Bonzini
2020-03-30 14:48     ` Markus Armbruster [this message]

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