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Subject[PATCH] dmaengine: axi-dmac: Use struct_size() in kzalloc()
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/dma-axi-dmac.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/drivers/dma/dma-axi-dmac.c b/drivers/dma/dma-axi-dmac.c
index 15b2453d2647..ffc0adc2f6ce 100644
--- a/drivers/dma/dma-axi-dmac.c
+++ b/drivers/dma/dma-axi-dmac.c
@@ -367,8 +367,7 @@ static struct axi_dmac_desc *axi_dmac_alloc_desc(unsigned int num_sgs)
struct axi_dmac_desc *desc;
unsigned int i;

- desc = kzalloc(sizeof(struct axi_dmac_desc) +
- sizeof(struct axi_dmac_sg) * num_sgs, GFP_NOWAIT);
+ desc = kzalloc(struct_size(desc, sg, num_sgs), GFP_NOWAIT);
if (!desc)
return NULL;

--
2.20.1
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