[PATCH 9/14] drivers/video: Move dereference after NULL test

From: Julia Lawall
Date: Sat Oct 17 2009 - 02:41:32 EST


From: Julia Lawall <julia@xxxxxxx>

If the NULL test on fbi is needed, then the dereference should be after the
NULL test.

A simplified version of the semantic match that detects this problem is as
follows (http://coccinelle.lip6.fr/):

// <smpl>
@match exists@
expression x, E;
identifier fld;
@@

* x->fld
... when != \(x = E\|&x\)
* x == NULL
// </smpl>

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

---
drivers/video/pxafb.c | 5 +++--
1 files changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/video/pxafb.c b/drivers/video/pxafb.c
index 1820c4a..fe3172c 100644
--- a/drivers/video/pxafb.c
+++ b/drivers/video/pxafb.c
@@ -1208,13 +1208,14 @@ static void setup_smart_timing(struct pxafb_info *fbi,
static int pxafb_smart_thread(void *arg)
{
struct pxafb_info *fbi = arg;
- struct pxafb_mach_info *inf = fbi->dev->platform_data;
+ struct pxafb_mach_info *inf;

- if (!fbi || !inf->smart_update) {
+ if (!fbi || !fbi->dev->platform_data->smart_update) {
pr_err("%s: not properly initialized, thread terminated\n",
__func__);
return -EINVAL;
}
+ inf = fbi->dev->platform_data;

pr_debug("%s(): task starting\n", __func__);

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