* [PATCH] ioat/dca: Use struct_size() helper
@ 2019-08-28 18:40 Gustavo A. R. Silva
2019-08-28 19:38 ` Dave Jiang
2019-09-04 4:48 ` Vinod Koul
0 siblings, 2 replies; 3+ messages in thread
From: Gustavo A. R. Silva @ 2019-08-28 18:40 UTC (permalink / raw)
To: Vinod Koul, Dan Williams; +Cc: dmaengine, linux-kernel, 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 ioat_dca_priv {
...
struct ioat_dca_slot req_slots[0];
};
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(*ioatdca) + (sizeof(struct ioat_dca_slot) * slots)
with:
struct_size(ioatdca, req_slots, slots)
This code was detected with the help of Coccinelle.
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
---
drivers/dma/ioat/dca.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)
diff --git a/drivers/dma/ioat/dca.c b/drivers/dma/ioat/dca.c
index 70fd8454d002..be61c32a876f 100644
--- a/drivers/dma/ioat/dca.c
+++ b/drivers/dma/ioat/dca.c
@@ -286,8 +286,7 @@ struct dca_provider *ioat_dca_init(struct pci_dev *pdev, void __iomem *iobase)
return NULL;
dca = alloc_dca_provider(&ioat_dca_ops,
- sizeof(*ioatdca)
- + (sizeof(struct ioat_dca_slot) * slots));
+ struct_size(ioatdca, req_slots, slots));
if (!dca)
return NULL;
--
2.23.0
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH] ioat/dca: Use struct_size() helper
2019-08-28 18:40 [PATCH] ioat/dca: Use struct_size() helper Gustavo A. R. Silva
@ 2019-08-28 19:38 ` Dave Jiang
2019-09-04 4:48 ` Vinod Koul
1 sibling, 0 replies; 3+ messages in thread
From: Dave Jiang @ 2019-08-28 19:38 UTC (permalink / raw)
To: Gustavo A. R. Silva, Vinod Koul, Williams, Dan J; +Cc: dmaengine, linux-kernel
On 8/28/19 11:40 AM, 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 ioat_dca_priv {
> ...
> struct ioat_dca_slot req_slots[0];
> };
>
> 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(*ioatdca) + (sizeof(struct ioat_dca_slot) * slots)
>
> with:
>
> struct_size(ioatdca, req_slots, slots)
>
> This code was detected with the help of Coccinelle.
>
> Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Acked-by: Dave Jiang <dave.jiang@intel.com>
> ---
> drivers/dma/ioat/dca.c | 3 +--
> 1 file changed, 1 insertion(+), 2 deletions(-)
>
> diff --git a/drivers/dma/ioat/dca.c b/drivers/dma/ioat/dca.c
> index 70fd8454d002..be61c32a876f 100644
> --- a/drivers/dma/ioat/dca.c
> +++ b/drivers/dma/ioat/dca.c
> @@ -286,8 +286,7 @@ struct dca_provider *ioat_dca_init(struct pci_dev *pdev, void __iomem *iobase)
> return NULL;
>
> dca = alloc_dca_provider(&ioat_dca_ops,
> - sizeof(*ioatdca)
> - + (sizeof(struct ioat_dca_slot) * slots));
> + struct_size(ioatdca, req_slots, slots));
> if (!dca)
> return NULL;
>
>
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH] ioat/dca: Use struct_size() helper
2019-08-28 18:40 [PATCH] ioat/dca: Use struct_size() helper Gustavo A. R. Silva
2019-08-28 19:38 ` Dave Jiang
@ 2019-09-04 4:48 ` Vinod Koul
1 sibling, 0 replies; 3+ messages in thread
From: Vinod Koul @ 2019-09-04 4:48 UTC (permalink / raw)
To: Gustavo A. R. Silva; +Cc: Dan Williams, dmaengine, linux-kernel
On 28-08-19, 13:40, 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 ioat_dca_priv {
> ...
> struct ioat_dca_slot req_slots[0];
> };
>
> 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(*ioatdca) + (sizeof(struct ioat_dca_slot) * slots)
>
> with:
>
> struct_size(ioatdca, req_slots, slots)
>
> This code was detected with the help of Coccinelle.
Please do not invent subsystem tags, git log should tell you the
convention to be used!
Applied after fixing tags, thanks
--
~Vinod
^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2019-09-04 4:49 UTC | newest]
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2019-08-28 18:40 [PATCH] ioat/dca: Use struct_size() helper Gustavo A. R. Silva
2019-08-28 19:38 ` Dave Jiang
2019-09-04 4:48 ` Vinod Koul
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