| Message ID | 20190104173733.GA29979@embeddedor |
|---|---|
| State | New |
| Headers | show |
| Series | pinctrl: mcp23s08: use struct_size() in devm_kzalloc() | expand |
On Fri, Jan 4, 2019 at 6:37 PM Gustavo A. R. Silva <gustavo@embeddedor.com> 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 = devm_kzalloc(dev, 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 = devm_kzalloc(dev, 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> Patch applied. Yours, Linus Walleij
diff --git a/drivers/pinctrl/pinctrl-mcp23s08.c b/drivers/pinctrl/pinctrl-mcp23s08.c index b03481ef99a1..6b4def13df8f 100644 --- a/drivers/pinctrl/pinctrl-mcp23s08.c +++ b/drivers/pinctrl/pinctrl-mcp23s08.c @@ -1139,8 +1139,7 @@ static int mcp23s08_probe(struct spi_device *spi) return -ENODEV; data = devm_kzalloc(&spi->dev, - sizeof(*data) + chips * sizeof(struct mcp23s08), - GFP_KERNEL); + struct_size(data, chip, chips), GFP_KERNEL); if (!data) return -ENOMEM;
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 = devm_kzalloc(dev, 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 = devm_kzalloc(dev, 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/pinctrl/pinctrl-mcp23s08.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-)