[PATCH 1/5] common: don't (kind of) open-code rcu_lock_domain_by_any_id()

[Jan Beulich <jbeulich@xxxxxxxx>]

Even more so when using rcu_lock_domain_by_id() in place of the more
efficient rcu_lock_current_domain().

Signed-off-by: Jan Beulich <jbeulich@xxxxxxxx>
---
Besides get_pg_owner(), gnttab_copy_lock_domain() has similar strange(?)
behavior: They accept DOMID_SELF, but not the resolved ID of the caller.
---
v4: New.

--- a/xen/common/event_channel.c
+++ b/xen/common/event_channel.c
@@ -353,10 +353,7 @@ static int evtchn_bind_interdomain(evtch
     evtchn_port_t  rport = bind->remote_port;
     domid_t        rdom = bind->remote_dom;
 
-    if ( rdom == DOMID_SELF )
-        rdom = current->domain->domain_id;
-
-    if ( (rd = rcu_lock_domain_by_id(rdom)) == NULL )
+    if ( (rd = rcu_lock_domain_by_any_id(rdom)) == NULL )
         return -ESRCH;
 
     write_lock(&ld->event_lock);
--- a/xen/common/page_alloc.c
+++ b/xen/common/page_alloc.c
@@ -2568,12 +2568,6 @@ struct domain *get_pg_owner(domid_t domi
 {
     struct domain *pg_owner = NULL, *curr = current->domain;
 
-    if ( likely(domid == DOMID_SELF) )
-    {
-        pg_owner = rcu_lock_current_domain();
-        goto out;
-    }
-
     if ( unlikely(domid == curr->domain_id) )
     {
         gdprintk(XENLOG_WARNING, "Cannot specify itself as foreign domain\n");
@@ -2591,7 +2585,7 @@ struct domain *get_pg_owner(domid_t domi
         break;
 
     default:
-        if ( (pg_owner = rcu_lock_domain_by_id(domid)) == NULL )
+        if ( (pg_owner = rcu_lock_domain_by_any_id(domid)) == NULL )
             gdprintk(XENLOG_WARNING, "Unknown domain d%d\n", domid);
         break;
     }