staging: iio: Use kcalloc instead of kzalloc to allocate array

The advantage of kcalloc is, that will prevent integer overflows which could
result from the multiplication of number of elements and size and it is also
a bit nicer to read.

The semantic patch that makes this change is available
in https://lkml.org/lkml/2011/11/25/107

Signed-off-by: Thomas Meyer <thomas@m3y3r.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/staging/iio/accel/lis3l02dq_ring.c

@@ -93,8 +93,7 @@ static int lis3l02dq_read_all(struct iio_dev *indio_dev, u8 *rx_array)
 	struct spi_message msg;
 	int ret, i, j = 0;
 
-	xfers = kzalloc((buffer->scan_count) * 2
-			* sizeof(*xfers), GFP_KERNEL);
+	xfers = kcalloc((buffer->scan_count) * 2, sizeof(*xfers), GFP_KERNEL);
 	if (!xfers)
 		return -ENOMEM;
 

drivers/staging/iio/adc/ad7280a.c

@@ -488,8 +488,8 @@ static int ad7280_channel_init(struct ad7280_state *st)
 {
 	int dev, ch, cnt;
 
-	st->channels = kzalloc(sizeof(*st->channels) *
-				((st->slave_num + 1) * 12 + 2), GFP_KERNEL);
+	st->channels = kcalloc((st->slave_num + 1) * 12 + 2,
+			       sizeof(*st->channels), GFP_KERNEL);
 	if (st->channels == NULL)
 		return -ENOMEM;
 
@@ -683,7 +683,7 @@ static irqreturn_t ad7280_event_handler(int irq, void *private)
 	unsigned *channels;
 	int i, ret;
 
-	channels = kzalloc(sizeof(*channels) * st->scan_cnt, GFP_KERNEL);
+	channels = kcalloc(st->scan_cnt, sizeof(*channels), GFP_KERNEL);
 	if (channels == NULL)
 		return IRQ_HANDLED;
 

drivers/staging/iio/iio_simple_dummy.c

@@ -518,7 +518,8 @@ static __init int iio_dummy_init(void)
 		return -EINVAL;
 	}
 	/* Fake a bus */
-	iio_dummy_devs = kzalloc(sizeof(*iio_dummy_devs)*instances, GFP_KERNEL);
+	iio_dummy_devs = kcalloc(instances, sizeof(*iio_dummy_devs),
+				 GFP_KERNEL);
 	/* Here we have no actual device so call probe */
 	for (i = 0; i < instances; i++) {
 		ret = iio_dummy_probe(i);

drivers/staging/iio/industrialio-buffer.c

@@ -315,10 +315,9 @@ int iio_buffer_register(struct iio_dev *indio_dev,
 			attrcount += ret;
 		}
 		if (indio_dev->masklength && buffer->scan_mask == NULL) {
-			buffer->scan_mask
-				= kzalloc(sizeof(*buffer->scan_mask)*
-					  BITS_TO_LONGS(indio_dev->masklength),
-					  GFP_KERNEL);
+			buffer->scan_mask = kcalloc(BITS_TO_LONGS(indio_dev->masklength),
+						    sizeof(*buffer->scan_mask),
+						    GFP_KERNEL);
 			if (buffer->scan_mask == NULL) {
 				ret = -ENOMEM;
 				goto error_cleanup_dynamic;
@@ -328,10 +327,9 @@ int iio_buffer_register(struct iio_dev *indio_dev,
 
 	buffer->scan_el_group.name = iio_scan_elements_group_name;
 
-	buffer->scan_el_group.attrs
-		= kzalloc(sizeof(buffer->scan_el_group.attrs[0])*
-			  (attrcount + 1),
-			  GFP_KERNEL);
+	buffer->scan_el_group.attrs = kcalloc(attrcount + 1,
+					      sizeof(buffer->scan_el_group.attrs[0]),
+					      GFP_KERNEL);
 	if (buffer->scan_el_group.attrs == NULL) {
 		ret = -ENOMEM;
 		goto error_free_scan_mask;

drivers/staging/iio/industrialio-core.c

@@ -669,10 +669,9 @@ static int iio_device_register_sysfs(struct iio_dev *indio_dev)
 	if (indio_dev->name)
 		attrcount++;
 
-	indio_dev->chan_attr_group.attrs
-		= kzalloc(sizeof(indio_dev->chan_attr_group.attrs[0])*
-			  (attrcount + 1),
-			  GFP_KERNEL);
+	indio_dev->chan_attr_group.attrs = kcalloc(attrcount + 1,
+						   sizeof(indio_dev->chan_attr_group.attrs[0]),
+						   GFP_KERNEL);
 	if (indio_dev->chan_attr_group.attrs == NULL) {
 		ret = -ENOMEM;
 		goto error_clear_attrs;
@@ -965,10 +964,9 @@ static int iio_device_register_eventset(struct iio_dev *indio_dev)
 	}
 
 	indio_dev->event_interface->group.name = iio_event_group_name;
-	indio_dev->event_interface->group.attrs =
-		kzalloc(sizeof(indio_dev->event_interface->group.attrs[0])
-			*(attrcount + 1),
-			GFP_KERNEL);
+	indio_dev->event_interface->group.attrs = kcalloc(attrcount + 1,
+							  sizeof(indio_dev->event_interface->group.attrs[0]),
+							  GFP_KERNEL);
 	if (indio_dev->event_interface->group.attrs == NULL) {
 		ret = -ENOMEM;
 		goto error_free_setup_event_lines;

drivers/staging/iio/meter/ade7758_core.c

@@ -746,12 +746,12 @@ static int __devinit ade7758_probe(struct spi_device *spi)
 	spi_set_drvdata(spi, indio_dev);
 
 	/* Allocate the comms buffers */
-	st->rx = kzalloc(sizeof(*st->rx)*ADE7758_MAX_RX, GFP_KERNEL);
+	st->rx = kcalloc(ADE7758_MAX_RX, sizeof(*st->rx), GFP_KERNEL);
 	if (st->rx == NULL) {
 		ret = -ENOMEM;
 		goto error_free_dev;
 	}
-	st->tx = kzalloc(sizeof(*st->tx)*ADE7758_MAX_TX, GFP_KERNEL);
+	st->tx = kcalloc(ADE7758_MAX_TX, sizeof(*st->tx), GFP_KERNEL);
 	if (st->tx == NULL) {
 		ret = -ENOMEM;
 		goto error_free_rx;