dmaengine: fsl-edma: 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 <[email protected]>

---
 drivers/dma/fsl-edma-common.c | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

drivers/dma/fsl-edma-common.c +0 -0

index 8876c4c1bb2c..fe529100674f 100644

Signature · 1 line

2.20.1

Quoted 31 lines · 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 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 <[email protected]>

---
  drivers/dma/fsl-edma-common.c | 4 +---
  1 file changed, 1 insertion(+), 3 deletions(-)

drivers/dma/fsl-edma-common.c +0 -0

index 8876c4c1bb2c..fe529100674f 100644
@@ -339,9 +339,7 @@ static struct fsl_edma_desc *fsl_edma_alloc_desc(struct fsl_edma_chan *fsl_chan,
  	struct fsl_edma_desc *fsl_desc;
  	int i;
 

drivers/dma/fsl-edma-common.c static struct fsl_edma_desc *fsl_edma_alloc_desc(struct fsl_edma_chan *fsl_chan, · line 345

Quoted 7 lines

drivers/dma/fsl-edma-common.c +1 -3

-	fsl_desc = kzalloc(sizeof(*fsl_desc) +
-			   sizeof(struct fsl_edma_sw_tcd) *
-			   sg_len, GFP_NOWAIT);
+	fsl_desc = kzalloc(struct_size(fsl_desc, tcd, sg_len), GFP_NOWAIT);
  	if (!fsl_desc)
  		return NULL;
 

Tested-by Angelo Dureghello <[email protected]>

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.