Functions like devm_kzalloc, kmalloc_array, devm_ioremap,
usb_alloc_urb, alloc_netdev return NULL as a return value on failure.
Generally, When NULL represents failure, !x is commonly used.
This patch cleans up the tests on the results of these functions, thereby
using !x instead of x == NULL or NULL == x. This is done via following
coccinelle script:
@prob_7@
identifier x;
statement S;
@@
(
x = devm_kzalloc(...);
|
x = usb_alloc_urb(...);
|
x = kmalloc_array(...);
|
x = devm_ioremap(...);
|
x = alloc_netdev(...);
)
...
- if(NULL == x)
+ if(!x)
S
Further we have used isomorphism characteristics of coccinelle to
indicate x == NULL and NULL == x are equivalent. This is done via
following iso script.
Expression
@ is_null @ expression X; @@
X == NULL <=> NULL == X
Signed-off-by: Somya Anand <somyaanand214@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
dma_addr_t buf_addr;
data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
- if (data == NULL)
+ if (!data)
return -ENOMEM;
spin_lock_init(&data->lock);
init_waitqueue_head(&data->wait);
mtd->priv = nand;
name = devm_kzalloc(&pdev->dev, name_len + 1, GFP_KERNEL);
- if (name == NULL)
+ if (!name)
return -ENOMEM;
mtd->name = name;
return -ENODEV;
base = devm_ioremap(&pdev->dev, r->start, PAGE_SIZE);
- if (base == NULL)
+ if (!base)
return -ENOMEM;
version = readl(base + NAND_VERSION);
nand = devm_kzalloc(&pdev->dev, sizeof(*nand) +
sizeof(struct mtd_info) * num_dev, GFP_KERNEL);
- if (nand == NULL)
+ if (!nand)
return -ENOMEM;
mutex_init(&nand->lock);