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scsi: virtio_scsi: Use struct_size() helper

PATCH Applied Gustavo A. R. Silva 4 participants 7 messages Jun 19, 2019 – Jul 12, 2019

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SCSI virtio core virtio block and SCSI drivers
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Gustavo A. R. Silva

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#0 lore raw

PATCH 1/1 scsi: virtio_scsi: Use struct_size() helper

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 <[email protected]>
---
 drivers/scsi/virtio_scsi.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
drivers/scsi/virtio_scsi.c +1 -1
index 13f1b3b9923a..ed4f79bffc73 100644
@@ -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;
Signature · 1 line
2.21.0
reviewer Reviewed-by on v1 1/1
#1 lore raw
Quoted 18 lines · Gustavo A. R. Silva

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:

Quoted 8 lines

struct_size(vscsi, req_vqs, num_queues)

This code was detected with the help of Coccinelle.

Signed-off-by Gustavo A. R. Silva <[email protected]>
---
 drivers/scsi/virtio_scsi.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
Reviewed-by Stefan Hajnoczi <[email protected]>
reviewer Reviewed-by on v1 1/1
#2 lore raw
In reply to Gustavo A. R. Silva
Quoted 18 lines · Gustavo A. R. Silva

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:

Quoted 8 lines

struct_size(vscsi, req_vqs, num_queues)

This code was detected with the help of Coccinelle.

Signed-off-by Gustavo A. R. Silva <[email protected]>
---
 drivers/scsi/virtio_scsi.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
Reviewed-by Stefan Hajnoczi <[email protected]>

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Applied
#3 lore raw
In reply to Gustavo A. R. Silva

Gustavo,

Quoted 3 lines

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!

Signature · 1 line
Martin K. Petersen	Oracle Linux Engineering
maintainer
#4 lore raw
Quoted 8 lines · Martin K. Petersen

Gustavo,

Quoted 3 lines

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 :)

Quoted 2 lines
Signature · 1 line
Martin K. Petersen	Oracle Linux Engineering
maintainer
#5 lore raw
In reply to Martin K. Petersen
Quoted 8 lines · Martin K. Petersen

Gustavo,

Quoted 3 lines

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 :)

Quoted 2 lines
Signature · 1 line
Martin K. Petersen	Oracle Linux Engineering
Applied
#6 lore raw
In reply to Gustavo A. R. Silva

Gustavo,

Quoted 3 lines

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!

Signature · 1 line
Martin K. Petersen	Oracle Linux Engineering