Jun 04 2014

staging: tidspbridge: use safer test on the result of find_first_zero_bit 

Author: Julia Lawall <Julia.Lawall@lip6.fr>

Find_first_zero_bit considers BITS_PER_LONG bits at a time, and thus may
return a larger number than the maximum position argument if that position
is not a multiple of BITS_PER_LONG.

The semantic match that finds this problem is as follows:
(http://coccinelle.lip6.fr/)

// 
@@
expression e1,e2,e3;
statement S1,S2;
@@

e1 = find_first_zero_bit(e2,e3)
...
if (e1
- ==
+ >=
  e3)
S1 else S2
// 

Signed-off-by: Julia Lawall 
Signed-off-by: Greg Kroah-Hartman 

---
 drivers/staging/tidspbridge/rmgr/node.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)
 
diff --git a/drivers/staging/tidspbridge/rmgr/node.c b/drivers/staging/tidspbridge/rmgr/node.c
index 9d3044a..305f3a6 100644
--- a/drivers/staging/tidspbridge/rmgr/node.c
+++ b/drivers/staging/tidspbridge/rmgr/node.c
@@ -935,7 +935,7 @@ int node_connect(struct node_object *node1, u32 stream1,
 				 node2_type == NODE_DAISSOCKET)) {
 		/* Find available pipe */
 		pipe_id = find_first_zero_bit(hnode_mgr->pipe_map, MAXPIPES);
-		if (pipe_id == MAXPIPES) {
+		if (pipe_id >= MAXPIPES) {
 			status = -ECONNREFUSED;
 			goto out_unlock;
 		}
@@ -1008,7 +1008,7 @@ int node_connect(struct node_object *node1, u32 stream1,
 			status = -EINVAL;
 			goto out_unlock;
 		}
-		if (chnl_id == CHNL_MAXCHANNELS) {
+		if (chnl_id >= CHNL_MAXCHANNELS) {
 			status = -ECONNREFUSED;
 			goto out_unlock;
 		}

qlambert