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 the pointer of
error_fatal, the user can't see this additional information, because
exit() happens in error_setg earlier than information is added [1].
The xen_netdev_connect() passes @errp to error_prepend(), and its @errp
parameter is from xen_device_frontend_changed().
Though its @errp points to @local_err of xen_device_frontend_changed(),
to follow the requirement of @errp, 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: Stefano Stabellini <sstabellini@kernel.org>
Cc: Anthony Perard <anthony.perard@citrix.com>
Cc: Paul Durrant <paul@xen.org>
Cc: Jason Wang <jasowang@redhat.com>
Signed-off-by: Zhao Liu <zhao1.liu@intel.com>
---
hw/net/xen_nic.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/hw/net/xen_nic.c b/hw/net/xen_nic.c
index 453fdb981983..89487b49baf9 100644
--- a/hw/net/xen_nic.c
+++ b/hw/net/xen_nic.c
@@ -351,6 +351,7 @@ static bool net_event(void *_xendev)
static bool xen_netdev_connect(XenDevice *xendev, Error **errp)
{
+ ERRP_GUARD();
XenNetDev *netdev = XEN_NET_DEVICE(xendev);
unsigned int port, rx_copy;