From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:43664) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Zoxay-0005Dh-97 for qemu-devel@nongnu.org; Wed, 21 Oct 2015 13:54:44 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1Zoxat-0006Ss-8c for qemu-devel@nongnu.org; Wed, 21 Oct 2015 13:54:40 -0400 Received: from e19.ny.us.ibm.com ([129.33.205.209]:56448) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Zoxat-0006Sh-2r for qemu-devel@nongnu.org; Wed, 21 Oct 2015 13:54:35 -0400 Received: from localhost by e19.ny.us.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Wed, 21 Oct 2015 13:54:34 -0400 From: Michael Roth Date: Wed, 21 Oct 2015 12:51:56 -0500 Message-Id: <1445449930-23525-27-git-send-email-mdroth@linux.vnet.ibm.com> In-Reply-To: <1445449930-23525-1-git-send-email-mdroth@linux.vnet.ibm.com> References: <1445449930-23525-1-git-send-email-mdroth@linux.vnet.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Subject: [Qemu-devel] [PATCH 26/40] qom: Fix invalid error check in property_get_str() List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: Michael Roth , =?UTF-8?q?Andreas=20F=C3=A4rber?= , qemu-stable@nongnu.org, Anthony Liguori , Markus Armbruster From: Markus Armbruster When a function returns a null pointer on error and only on error, you can do if (!foo(foos, errp)) { ... handle error ... } instead of the more cumbersome Error *err = NULL; if (!foo(foos, &err)) { error_propagate(errp, err); ... handle error ... } A StringProperty's getter, however, may return null on success! We then fail to call visit_type_str(). Screwed up in 6a146eb, v1.1. Fails tests/qom-test in my current, heavily hacked QAPI branch. No reproducer for master known (but I didn't look hard). Cc: Anthony Liguori Signed-off-by: Markus Armbruster Reviewed-by: Eric Blake Cc: qemu-stable@nongnu.org Signed-off-by: Andreas Färber (cherry picked from commit e1c8237df5395f6a453f18109bd9dd33fb2a397c) Signed-off-by: Michael Roth --- qom/object.c | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-) diff --git a/qom/object.c b/qom/object.c index c9aedd0..e14b9d8 100644 --- a/qom/object.c +++ b/qom/object.c @@ -1593,12 +1593,16 @@ static void property_get_str(Object *obj, Visitor *v, void *opaque, { StringProperty *prop = opaque; char *value; + Error *err = NULL; - value = prop->get(obj, errp); - if (value) { - visit_type_str(v, &value, name, errp); - g_free(value); + value = prop->get(obj, &err); + if (err) { + error_propagate(errp, err); + return; } + + visit_type_str(v, &value, name, errp); + g_free(value); } static void property_set_str(Object *obj, Visitor *v, void *opaque, -- 1.9.1