[PATCH 9/9] drivers/staging/media/as102/as102_usb_drv.c: shift position of allocation code

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



The conditional after the kzalloc says that the tested expression should
never be true, but if it were, the allocated data would have to be freed.
This change just moves the allocation below the test, to avoid any
possibility of the problem.

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

// <smpl>
@r exists@
local idexpression x;
statement S;
identifier f1;
position p1,p2;
expression *ptr != NULL;
@@

x@p1 = \(kmalloc\|kzalloc\|kcalloc\)(...);
...
if (x == NULL) S
<... when != x
     when != if (...) { <+...x...+> }
x->f1
...>
(
 return \(0\|<+...x...+>\|ptr\);
|
 return@p2 ...;
)

@script:python@
p1 << r.p1;
p2 << r.p2;
@@

print "* file: %s kmalloc %s return %s" % (p1[0].file,p1[0].line,p2[0].line)
// </smpl>

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

---
 drivers/staging/media/as102/as102_usb_drv.c |   12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/drivers/staging/media/as102/as102_usb_drv.c b/drivers/staging/media/as102/as102_usb_drv.c
index 7bcb28c..d775be0 100644
--- a/drivers/staging/media/as102/as102_usb_drv.c
+++ b/drivers/staging/media/as102/as102_usb_drv.c
@@ -353,12 +353,6 @@ static int as102_usb_probe(struct usb_interface *intf,
 
 	ENTER();
 
-	as102_dev = kzalloc(sizeof(struct as102_dev_t), GFP_KERNEL);
-	if (as102_dev == NULL) {
-		err("%s: kzalloc failed", __func__);
-		return -ENOMEM;
-	}
-
 	/* This should never actually happen */
 	if ((sizeof(as102_usb_id_table) / sizeof(struct usb_device_id)) !=
 	    (sizeof(as102_device_names) / sizeof(const char *))) {
@@ -366,6 +360,12 @@ static int as102_usb_probe(struct usb_interface *intf,
 		return -EINVAL;
 	}
 
+	as102_dev = kzalloc(sizeof(struct as102_dev_t), GFP_KERNEL);
+	if (as102_dev == NULL) {
+		err("%s: kzalloc failed", __func__);
+		return -ENOMEM;
+	}
+
 	/* Assign the user-friendly device name */
 	for (i = 0; i < (sizeof(as102_usb_id_table) /
 			 sizeof(struct usb_device_id)); i++) {

--
To unsubscribe from this list: send the line "unsubscribe linux-media" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html


[Index of Archives]     [Linux Input]     [Video for Linux]     [Gstreamer Embedded]     [Mplayer Users]     [Linux USB Devel]     [Linux Audio Users]     [Linux Kernel]     [Linux SCSI]     [Yosemite Backpacking]
  Powered by Linux