Jul 19 2009

HID: Move dereferences below a NULL test 

Author: Julia Lawall <julia@diku.dk>

If the NULL test is necessary, then the dereferences should be moved below
the NULL test.

The semantic patch that makes this change is as follows:
(http://www.emn.fr/x-info/coccinelle/)

// 
@@
type T;
expression E,E1;
identifier i,fld;
statement S;
@@

- T i = E->fld;
+ T i;
  ... when != E=E1
      when != i
  if (E == NULL||...) S
+ i = E->fld;
// 

Signed-off-by: Julia Lawall 
Signed-off-by: Jiri Kosina 

---
 drivers/hid/hid-core.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)
 
diff --git a/drivers/hid/hid-core.c b/drivers/hid/hid-core.c
index f2c21d5..5eb10c2 100644
--- a/drivers/hid/hid-core.c
+++ b/drivers/hid/hid-core.c
@@ -1075,14 +1075,16 @@ EXPORT_SYMBOL_GPL(hid_report_raw_event);
  */
 int hid_input_report(struct hid_device *hid, int type, u8 *data, int size, int interrupt)
 {
-	struct hid_report_enum *report_enum = hid->report_enum + type;
-	struct hid_driver *hdrv = hid->driver;
+	struct hid_report_enum *report_enum;
+	struct hid_driver *hdrv;
 	struct hid_report *report;
 	unsigned int i;
 	int ret;
 
 	if (!hid || !hid->driver)
 		return -ENODEV;
+	report_enum = hid->report_enum + type;
+	hdrv = hid->driver;
 
 	if (!size) {
 		dbg_hid("empty report\n");

qlambert