Linux Virtualization - Jan 2017 - [PATCH 3/3] virtio_ring: Use kmalloc_array() in alloc_indirect()

From: Markus Elfring <elfring at users.sourceforge.net>
Date: Thu, 26 Jan 2017 22:40:02 +0100

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

Markus Elfring (3):
  virtio_pci: Use kcalloc() in vp_request_msix_vectors()
  virtio_pci: Use kmalloc_array() in vp_request_msix_vectors()
  virtio_ring: Use kmalloc_array() in alloc_indirect()

 drivers/virtio/virtio_pci_common.c | 8 ++++----
 drivers/virtio/virtio_ring.c       | 3 +--
 2 files changed, 5 insertions(+), 6 deletions(-)

-- 
2.11.0

From: Markus Elfring <elfring at users.sourceforge.net>
Date: Thu, 26 Jan 2017 22:10:18 +0100

A multiplication for the size determination of a memory allocation
indicated that an array data structure should be processed.
Thus reuse the corresponding function "kcalloc".

This issue was detected by using the Coccinelle software.

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

diff --git a/drivers/virtio/virtio_pci_common.c
b/drivers/virtio/virtio_pci_common.c
index 186cbab327b8..559a2b706093 100644
--- a/drivers/virtio/virtio_pci_common.c
+++ b/drivers/virtio/virtio_pci_common.c
@@ -117,7 +117,7 @@ static int vp_request_msix_vectors(struct virtio_device
*vdev, int nvectors,
 	if (!vp_dev->msix_names)
 		goto error;
 	vp_dev->msix_affinity_masks
-		= kzalloc(nvectors * sizeof *vp_dev->msix_affinity_masks,
+		= kcalloc(nvectors, sizeof(*vp_dev->msix_affinity_masks),
 			  GFP_KERNEL);
 	if (!vp_dev->msix_affinity_masks)
 		goto error;
-- 
2.11.0

From: Markus Elfring <elfring at users.sourceforge.net>
Date: Thu, 26 Jan 2017 22:20:30 +0100

A multiplication for the size determination of a memory allocation
indicated that an array data structure should be processed.
Thus reuse the corresponding function "kmalloc_array".

This issue was detected by using the Coccinelle software.

Signed-off-by: Markus Elfring <elfring at users.sourceforge.net>
---
 drivers/virtio/virtio_pci_common.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/virtio/virtio_pci_common.c
b/drivers/virtio/virtio_pci_common.c
index 559a2b706093..623a8cea1441 100644
--- a/drivers/virtio/virtio_pci_common.c
+++ b/drivers/virtio/virtio_pci_common.c
@@ -111,9 +111,9 @@ static int vp_request_msix_vectors(struct virtio_device
*vdev, int nvectors,
 	int err = -ENOMEM;
 
 	vp_dev->msix_vectors = nvectors;
-
-	vp_dev->msix_names = kmalloc(nvectors * sizeof *vp_dev->msix_names,
-				     GFP_KERNEL);
+	vp_dev->msix_names = kmalloc_array(nvectors,
+					   sizeof(*vp_dev->msix_names),
+					   GFP_KERNEL);
 	if (!vp_dev->msix_names)
 		goto error;
 	vp_dev->msix_affinity_masks
-- 
2.11.0

From: Markus Elfring <elfring at users.sourceforge.net>
Date: Thu, 26 Jan 2017 22:30:45 +0100

* A multiplication for the size determination of a memory allocation
  indicated that an array data structure should be processed.
  Thus use the corresponding function "kmalloc_array".

  This issue was detected by using the Coccinelle software.

* Replace the specification of a data structure by a pointer dereference
  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/virtio/virtio_ring.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c
index 409aeaa49246..34b6b694298c 100644
--- a/drivers/virtio/virtio_ring.c
+++ b/drivers/virtio/virtio_ring.c
@@ -247,8 +247,7 @@ static struct vring_desc *alloc_indirect(struct virtqueue
*_vq,
 	 * virtqueue.
 	 */
 	gfp &= ~__GFP_HIGHMEM;
-
-	desc = kmalloc(total_sg * sizeof(struct vring_desc), gfp);
+	desc = kmalloc_array(total_sg, sizeof(*desc), gfp);
 	if (!desc)
 		return NULL;
 
-- 
2.11.0

On 2017?01?27? 05:44, SF Markus Elfring wrote:
> From: Markus Elfring <elfring at users.sourceforge.net>
> Date: Thu, 26 Jan 2017 22:40:02 +0100
>
> A few update suggestions were taken into account
> from static source code analysis.
>
> Markus Elfring (3):
>    virtio_pci: Use kcalloc() in vp_request_msix_vectors()
>    virtio_pci: Use kmalloc_array() in vp_request_msix_vectors()
>    virtio_ring: Use kmalloc_array() in alloc_indirect()
>
>   drivers/virtio/virtio_pci_common.c | 8 ++++----
>   drivers/virtio/virtio_ring.c       | 3 +--
>   2 files changed, 5 insertions(+), 6 deletions(-)
>
Acked-by: Jason Wang <jasowang at redhat.com>