| Message ID | 20190109144437.GA10733@embeddedor (mailing list archive) |
|---|---|
| State | Accepted |
| Headers | show |
| Series | dmaengine: axi-dmac: Use struct_size() in kzalloc() | expand |
On 09-01-19, 08:44, 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. Applied, thanks
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;
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(-)