1 files changed, 17 insertions, 24 deletions

diff --git a/net/tipc/bcast.c b/net/tipc/bcast.c
index 1633ef201df..54128040a12 100644
--- a/net/tipc/bcast.c
+++ b/net/tipc/bcast.c
@@ -81,7 +81,14 @@ struct bcbearer_pair {
  * @bearer: (non-standard) broadcast bearer structure
  * @media: (non-standard) broadcast media structure
  * @bpairs: array of bearer pairs
- * @bpairs_temp: array of bearer pairs used during creation of "bpairs"
+ * @bpairs_temp: temporary array of bearer pairs used by tipc_bcbearer_sort()
+ * @remains: temporary node map used by tipc_bcbearer_send()
+ * @remains_new: temporary node map used tipc_bcbearer_send()
+ * 
+ * Note: The fields labelled "temporary" are incorporated into the bearer
+ * to avoid consuming potentially limited stack space through the use of
+ * large local variables within multicast routines.  Concurrent access is
+ * prevented through use of the spinlock "bc_lock".
  */
 
 struct bcbearer {
@@ -89,6 +96,8 @@ struct bcbearer {
         struct media media;
         struct bcbearer_pair bpairs[MAX_BEARERS];
         struct bcbearer_pair bpairs_temp[TIPC_MAX_LINK_PRI + 1];
+        struct node_map remains;
+        struct node_map remains_new;
 };
 
 /**
@@ -551,12 +560,8 @@ static int tipc_bcbearer_send(struct sk_buff *buf,
 {
         static int send_count = 0;
 
-        struct node_map *remains;
-        struct node_map *remains_new;
-        struct node_map *remains_tmp;
         int bp_index;
         int swap_time;
-        int err;
 
         /* Prepare buffer for broadcasting (if first time trying to send it) */
 
@@ -577,9 +582,7 @@ static int tipc_bcbearer_send(struct sk_buff *buf,
 
         /* Send buffer over bearers until all targets reached */
         
-        remains = kmalloc(sizeof(struct node_map), GFP_ATOMIC);
-        remains_new = kmalloc(sizeof(struct node_map), GFP_ATOMIC);
-        *remains = tipc_cltr_bcast_nodes;
+        bcbearer->remains = tipc_cltr_bcast_nodes;
 
         for (bp_index = 0; bp_index < MAX_BEARERS; bp_index++) {
                 struct bearer *p = bcbearer->bpairs[bp_index].primary;
@@ -588,8 +591,8 @@ static int tipc_bcbearer_send(struct sk_buff *buf,
                 if (!p)
                         break;  /* no more bearers to try */
 
-                tipc_nmap_diff(remains, &p->nodes, remains_new);
-                if (remains_new->count == remains->count)
+                tipc_nmap_diff(&bcbearer->remains, &p->nodes, &bcbearer->remains_new);
+                if (bcbearer->remains_new.count == bcbearer->remains.count)
                         continue;       /* bearer pair doesn't add anything */
 
                 if (!p->publ.blocked &&
@@ -607,27 +610,17 @@ swap:
                 bcbearer->bpairs[bp_index].primary = s;
                 bcbearer->bpairs[bp_index].secondary = p;
 update:
-                if (remains_new->count == 0) {
-                        err = TIPC_OK;
-                        goto out;
-                }
+                if (bcbearer->remains_new.count == 0)
+                        return TIPC_OK;
 
-                /* swap map */
-                remains_tmp = remains;
-                remains = remains_new;
-                remains_new = remains_tmp;
+                bcbearer->remains = bcbearer->remains_new;
         }
         
         /* Unable to reach all targets */
 
         bcbearer->bearer.publ.blocked = 1;
         bcl->stats.bearer_congs++;
-        err = ~TIPC_OK;
-
- out:
-        kfree(remains_new);
-        kfree(remains);
-        return err;
+        return ~TIPC_OK;
 }
 
 /**