| Message ID | 20190104183034.GA5364@embeddedor (mailing list archive) |
|---|---|
| State | Accepted |
| Headers | show |
| Series | dmaengine: bcm2835: Use struct_size() in kzalloc() | expand |
On 04-01-19, 12:30, 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/bcm2835-dma.c b/drivers/dma/bcm2835-dma.c index 1a44c8086d77..7beec403c2c9 100644 --- a/drivers/dma/bcm2835-dma.c +++ b/drivers/dma/bcm2835-dma.c @@ -312,8 +312,7 @@ static struct bcm2835_desc *bcm2835_dma_create_cb_chain( return NULL; /* allocate and setup the descriptor. */ - d = kzalloc(sizeof(*d) + frames * sizeof(struct bcm2835_cb_entry), - gfp); + d = kzalloc(struct_size(d, cb_list, frames), gfp); if (!d) 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/bcm2835-dma.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-)