From: Zhao Liu <zhao1.liu@intel.com>
As the comment in qapi/error, passing @errp to error_prepend() requires
ERRP_GUARD():
* = Why, when and how to use ERRP_GUARD() =
*
* Without ERRP_GUARD(), use of the @errp parameter is restricted:
...
* - It should not be passed to error_prepend(), error_vprepend() or
* error_append_hint(), because that doesn't work with &error_fatal.
* ERRP_GUARD() lifts these restrictions.
*
* To use ERRP_GUARD(), add it right at the beginning of the function.
* @errp can then be used without worrying about the argument being
* NULL or &error_fatal.
ERRP_GUARD() could avoid the case when @errp is &error_fatal, the user
can't see this additional information, because exit() happens in
error_setg earlier than information is added [1].
The vfio_ap_realize() passes @errp to error_prepend(), and as a
DeviceClass.realize method, there are too many possible callers to check
the impact of this defect; it may or may not be harmless. Thus it is
necessary to protect @errp with ERRP_GUARD().
To avoid the issue like [1] said, add missing ERRP_GUARD() at the
beginning of this function.
[1]: Issue description in the commit message of commit ae7c80a7bd73
("error: New macro ERRP_GUARD()").
Cc: Alex Williamson <alex.williamson@redhat.com>
Cc: "Cédric Le Goater" <clg@redhat.com>
Cc: Tony Krowiak <akrowiak@linux.ibm.com>
Cc: Halil Pasic <pasic@linux.ibm.com>
Cc: Jason Herne <jjherne@linux.ibm.com>
Cc: Thomas Huth <thuth@redhat.com>
Cc: qemu-s390x@nongnu.org
Signed-off-by: Zhao Liu <zhao1.liu@intel.com>
---
v2: Use Markus' sentence to polish commit message. (Markus)
---
hw/vfio/ap.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/hw/vfio/ap.c b/hw/vfio/ap.c
index e157aa1ff79c..7c4caa593863 100644
--- a/hw/vfio/ap.c
+++ b/hw/vfio/ap.c
@@ -155,6 +155,7 @@ static void vfio_ap_unregister_irq_notifier(VFIOAPDevice
*vapdev,
static void vfio_ap_realize(DeviceState *dev, Error **errp)
{
+ ERRP_GUARD();
int ret;
Error *err = NULL;
VFIOAPDevice *vapdev = VFIO_AP_DEVICE(dev);