[PATCH 3/5] drivers/media/video/{s2255drv.c,tm6000/tm6000-alsa.c,tm6000/tm6000-input.c}: Remove potential NULL dereferences

From: Julia Lawall
Date: Tue Aug 14 2012 - 11:51:32 EST


From: Julia Lawall <Julia.Lawall@xxxxxxx>

If the NULL test is necessary, the initialization involving a dereference of
the tested value should be moved after the NULL test.

The sematic patch that fixes this problem is as follows:
(http://coccinelle.lip6.fr/)

// <smpl>
@@
type T;
expression E;
identifier i,fld;
statement S;
@@

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

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

---
drivers/media/video/s2255drv.c | 3 ++-
drivers/media/video/tm6000/tm6000-alsa.c | 3 ++-
drivers/media/video/tm6000/tm6000-input.c | 3 ++-
3 files changed, 6 insertions(+), 3 deletions(-)

diff --git a/drivers/media/video/s2255drv.c b/drivers/media/video/s2255drv.c
index 6c7960c..a25513d 100644
--- a/drivers/media/video/s2255drv.c
+++ b/drivers/media/video/s2255drv.c
@@ -1861,11 +1861,12 @@ static int s2255_release(struct file *file)
static int s2255_mmap_v4l(struct file *file, struct vm_area_struct *vma)
{
struct s2255_fh *fh = file->private_data;
- struct s2255_dev *dev = fh->dev;
+ struct s2255_dev *dev;
int ret;

if (!fh)
return -ENODEV;
+ dev = fh->dev;
dprintk(4, "%s, vma=0x%08lx\n", __func__, (unsigned long)vma);
if (mutex_lock_interruptible(&dev->lock))
return -ERESTARTSYS;
diff --git a/drivers/media/video/tm6000/tm6000-alsa.c b/drivers/media/video/tm6000/tm6000-alsa.c
index bd07ec7..813c1ec 100644
--- a/drivers/media/video/tm6000/tm6000-alsa.c
+++ b/drivers/media/video/tm6000/tm6000-alsa.c
@@ -487,10 +487,11 @@ error:

static int tm6000_audio_fini(struct tm6000_core *dev)
{
- struct snd_tm6000_card *chip = dev->adev;
+ struct snd_tm6000_card *chip;

if (!dev)
return 0;
+ chip = dev->adev;

if (!chip)
return 0;
diff --git a/drivers/media/video/tm6000/tm6000-input.c b/drivers/media/video/tm6000/tm6000-input.c
index e80b7e1..dffbd4b 100644
--- a/drivers/media/video/tm6000/tm6000-input.c
+++ b/drivers/media/video/tm6000/tm6000-input.c
@@ -319,12 +319,13 @@ static int tm6000_ir_change_protocol(struct rc_dev *rc, u64 rc_type)
static int __tm6000_ir_int_start(struct rc_dev *rc)
{
struct tm6000_IR *ir = rc->priv;
- struct tm6000_core *dev = ir->dev;
+ struct tm6000_core *dev;
int pipe, size;
int err = -ENOMEM;

if (!ir)
return -ENODEV;
+ dev = ir->dev;

dprintk(2, "%s\n",__func__);


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