| Message ID | 20190619192833.GA825@embeddedor (mailing list archive) |
|---|---|
| State | Mainlined |
| Commit | 211f70ff1daa3b3bb877f0f6fa85a42ef50f8341 |
| Headers | show |
| Series | scsi: virtio_scsi: Use struct_size() helper | expand |
On Wed, Jun 19, 2019 at 02:28:33PM -0500, Gustavo A. R. Silva wrote: > One of the more common cases of allocation size calculations is finding > the size of a structure that has a zero-sized array at the end, along > with memory for some number of elements for that array. For example: > > struct virtio_scsi { > ... > struct virtio_scsi_vq req_vqs[]; > }; > > Make use of the struct_size() helper instead of an open-coded version > in order to avoid any potential type mistakes. > > So, replace the following form: > > sizeof(*vscsi) + sizeof(vscsi->req_vqs[0]) * num_queues > > with: > > struct_size(vscsi, req_vqs, num_queues) > > This code was detected with the help of Coccinelle. > > Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com> > --- > drivers/scsi/virtio_scsi.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Gustavo, > One of the more common cases of allocation size calculations is finding > the size of a structure that has a zero-sized array at the end, along > with memory for some number of elements for that array. For example: Applied to 5.4/scsi-queue, thanks!
On Thu, Jul 11, 2019 at 08:18:54PM -0400, Martin K. Petersen wrote: > > Gustavo, > > > One of the more common cases of allocation size calculations is finding > > the size of a structure that has a zero-sized array at the end, along > > with memory for some number of elements for that array. For example: > > Applied to 5.4/scsi-queue, thanks! Oh I put it in the virtio tree already. Can't hurt I guess :) > -- > Martin K. Petersen Oracle Linux Engineering
diff --git a/drivers/scsi/virtio_scsi.c b/drivers/scsi/virtio_scsi.c index 13f1b3b9923a..ed4f79bffc73 100644 --- a/drivers/scsi/virtio_scsi.c +++ b/drivers/scsi/virtio_scsi.c @@ -795,7 +795,7 @@ static int virtscsi_probe(struct virtio_device *vdev) num_targets = virtscsi_config_get(vdev, max_target) + 1; shost = scsi_host_alloc(&virtscsi_host_template, - sizeof(*vscsi) + sizeof(vscsi->req_vqs[0]) * num_queues); + struct_size(vscsi, req_vqs, num_queues)); if (!shost) return -ENOMEM;
One of the more common cases of allocation size calculations is finding the size of a structure that has a zero-sized array at the end, along with memory for some number of elements for that array. For example: struct virtio_scsi { ... struct virtio_scsi_vq req_vqs[]; }; Make use of the struct_size() helper instead of an open-coded version in order to avoid any potential type mistakes. So, replace the following form: sizeof(*vscsi) + sizeof(vscsi->req_vqs[0]) * num_queues with: struct_size(vscsi, req_vqs, num_queues) This code was detected with the help of Coccinelle. Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com> --- drivers/scsi/virtio_scsi.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)