Functions that take an Error ** parameter to pass an error to the
caller expect the parameter to point to null.
failover_replug_primary() violates this precondition in several
places:
* After qemu_opts_from_qdict() failed, *errp is no longer null.
Passing it to error_setg() is wrong, and will trip the assertion in
error_setv(). Messed up in commit 150ab54aa6 "net/virtio: fix
re-plugging of primary device". Simply drop the error_setg().
* Passing @errp to qemu_opt_set_bool(), hotplug_handler_pre_plug(),
and hotplug_handler_plug() is wrong. If one of the first two fails,
*errp is no longer null. Risks tripping the same assertion.
Moreover, continuing after such errors is unsafe. Messed up in
commit 9711cd0dfc "net/virtio: add failover support". Fix by
handling each error properly.
failover_replug_primary() crashes when passed a null @errp. Also
messed up in commit 9711cd0dfc. This bug can't bite as no caller
actually passes null. Fix it anyway.
Fixes: 9711cd0dfc3fa414f7f64935713c07134ae67971
Fixes: 150ab54aa6934583180f88a2bd540bc6fc4fbff3
Cc: Jens Freimann <jfreimann@redhat.com>
Cc: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20191130194240.10517-3-armbru@redhat.com>
Reviewed-by: Jens Freimann <jfreimann@redhat.com>
5a0948d36c