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SubjectRe: [PATCH] dmaengine: st_fdma: use struct_size() in kzalloc()
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Hi Gustavo

On 1/4/19 7:43 PM, 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 foo {
> int stuff;
> void *entry[];
> };
>
> instance = kzalloc(sizeof(struct foo) + sizeof(void *) * count, GFP_KERNEL);
>
> Instead of leaving these open-coded and prone to type mistakes, we can now
> use the new struct_size() helper:
>
> instance = kzalloc(struct_size(instance, entry, count), GFP_KERNEL);
>
> This code was detected with the help of Coccinelle.
>
> Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
> ---
> drivers/dma/st_fdma.c | 3 +--
> 1 file changed, 1 insertion(+), 2 deletions(-)
>
> diff --git a/drivers/dma/st_fdma.c b/drivers/dma/st_fdma.c
> index 07c20aa2e955..df6b73028ecb 100644
> --- a/drivers/dma/st_fdma.c
> +++ b/drivers/dma/st_fdma.c
> @@ -243,8 +243,7 @@ static struct st_fdma_desc *st_fdma_alloc_desc(struct st_fdma_chan *fchan,
> struct st_fdma_desc *fdesc;
> int i;
>
> - fdesc = kzalloc(sizeof(*fdesc) +
> - sizeof(struct st_fdma_sw_node) * sg_len, GFP_NOWAIT);
> + fdesc = kzalloc(struct_size(fdesc, node, sg_len), GFP_NOWAIT);
> if (!fdesc)
> return NULL;
>
>


Acked-by: Patrice Chotard <patrice.chotard@st.com>

Thanks
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