[PATCH 4/10] staging: tidspbridge: use safer test on the result of find_first_zero_bit

From: Julia Lawall
Date: Wed Jun 04 2014 - 05:13:07 EST


From: Julia Lawall <Julia.Lawall@xxxxxxx>

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/)

// <smpl>
@@
expression e1,e2,e3;
statement S1,S2;
@@

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

Signed-off-by: Julia Lawall <Julia.Lawall@xxxxxxx>

---
drivers/staging/tidspbridge/rmgr/node.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff -u -p a/drivers/staging/tidspbridge/rmgr/node.c b/drivers/staging/tidspbridge/rmgr/node.c
--- a/drivers/staging/tidspbridge/rmgr/node.c
+++ b/drivers/staging/tidspbridge/rmgr/node.c
@@ -935,7 +935,7 @@ int node_connect(struct node_object *nod
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 *nod
status = -EINVAL;
goto out_unlock;
}
- if (chnl_id == CHNL_MAXCHANNELS) {
+ if (chnl_id >= CHNL_MAXCHANNELS) {
status = -ECONNREFUSED;
goto out_unlock;
}

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