Linux Virtualization - May 2017 - [PATCH 2/3] s390: virtio: Improve a size determination in virtio_ccw_setup_vq()

From: Markus Elfring <elfring at users.sourceforge.net>
Date: Tue, 16 May 2017 17:43:21 +0200

A few update suggestions were taken into account
from static source code analysis.

Markus Elfring (3):
  Delete error messages for failed memory allocations in two functions
  Improve a size determination in virtio_ccw_setup_vq()
  Adjust a null pointer check in two functions

 drivers/s390/virtio/virtio_ccw.c | 9 +++------
 1 file changed, 3 insertions(+), 6 deletions(-)

-- 
2.13.0

From: Markus Elfring <elfring at users.sourceforge.net>
Date: Tue, 16 May 2017 16:50:17 +0200

Omit three extra messages for memory allocation failures in these functions.

This issue was detected by using the Coccinelle software.

Link:
http://events.linuxfoundation.org/sites/events/files/slides/LCJ16-Refactor_Strings-WSang_0.pdf
Signed-off-by: Markus Elfring <elfring at users.sourceforge.net>
---
 drivers/s390/virtio/virtio_ccw.c | 3 ---
 1 file changed, 3 deletions(-)

diff --git a/drivers/s390/virtio/virtio_ccw.c b/drivers/s390/virtio/virtio_ccw.c
index 2a76ea78a0bf..447fe718c0ab 100644
--- a/drivers/s390/virtio/virtio_ccw.c
+++ b/drivers/s390/virtio/virtio_ccw.c
@@ -499,12 +499,10 @@ static struct virtqueue *virtio_ccw_setup_vq(struct
virtio_device *vdev,
 	if (!info) {
-		dev_warn(&vcdev->cdev->dev, "no info\n");
 		err = -ENOMEM;
 		goto out_err;
 	}
 	info->info_block = kzalloc(sizeof(*info->info_block),
 				   GFP_DMA | GFP_KERNEL);
 	if (!info->info_block) {
-		dev_warn(&vcdev->cdev->dev, "no info block\n");
 		err = -ENOMEM;
 		goto out_err;
 	}
@@ -1225,7 +1223,6 @@ static int virtio_ccw_online(struct ccw_device *cdev)
 
 	vcdev = kzalloc(sizeof(*vcdev), GFP_KERNEL);
 	if (!vcdev) {
-		dev_warn(&cdev->dev, "Could not get memory for virtio\n");
 		ret = -ENOMEM;
 		goto out_free;
 	}
-- 
2.13.0

From: Markus Elfring <elfring at users.sourceforge.net>
Date: Tue, 16 May 2017 17:05:01 +0200

Replace the specification of a data structure by a pointer dereference
as the parameter for the operator "sizeof" to make the corresponding
size
determination a bit safer according to the Linux coding style convention.

Signed-off-by: Markus Elfring <elfring at users.sourceforge.net>
---
 drivers/s390/virtio/virtio_ccw.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/s390/virtio/virtio_ccw.c b/drivers/s390/virtio/virtio_ccw.c
index 447fe718c0ab..bfb845d7faa7 100644
--- a/drivers/s390/virtio/virtio_ccw.c
+++ b/drivers/s390/virtio/virtio_ccw.c
@@ -495,5 +495,5 @@ static struct virtqueue *virtio_ccw_setup_vq(struct
virtio_device *vdev,
 	unsigned long flags;
 
 	/* Allocate queue. */
-	info = kzalloc(sizeof(struct virtio_ccw_vq_info), GFP_KERNEL);
+	info = kzalloc(sizeof(*info), GFP_KERNEL);
 	if (!info) {
-- 
2.13.0

From: Markus Elfring <elfring at users.sourceforge.net>
Date: Tue, 16 May 2017 17:14:26 +0200
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

The script ?checkpatch.pl? pointed information out like the following.

Comparison to NULL could be written ?

Thus fix the affected source code places.

Signed-off-by: Markus Elfring <elfring at users.sourceforge.net>
---
 drivers/s390/virtio/virtio_ccw.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/s390/virtio/virtio_ccw.c b/drivers/s390/virtio/virtio_ccw.c
index bfb845d7faa7..27ab0f0b59cd 100644
--- a/drivers/s390/virtio/virtio_ccw.c
+++ b/drivers/s390/virtio/virtio_ccw.c
@@ -513,7 +513,7 @@ static struct virtqueue *virtio_ccw_setup_vq(struct
virtio_device *vdev,
 	}
 	size = PAGE_ALIGN(vring_size(info->num, KVM_VIRTIO_CCW_RING_ALIGN));
 	info->queue = alloc_pages_exact(size, GFP_KERNEL | __GFP_ZERO);
-	if (info->queue == NULL) {
+	if (!info->queue) {
 		dev_warn(&vcdev->cdev->dev, "no queue\n");
 		err = -ENOMEM;
 		goto out_err;
@@ -1388,7 +1388,7 @@ static void __init no_auto_parse(void)
 				 &from_ssid, &from);
 		if (rc)
 			continue;
-		if (parm != NULL) {
+		if (parm) {
 			rc = parse_busid(parm, &to_cssid,
 					 &to_ssid, &to);
 			if ((from_ssid > to_ssid) ||
-- 
2.13.0