| Message ID | 20190131003355.GA27627@embeddedor |
|---|---|
| State | Accepted |
| Delegated to: | David Miller |
| Headers | show |
| Series | [net-next] tulip: eeprom: use struct_size() in kmalloc() | expand |
From: "Gustavo A. R. Silva" <gustavo@embeddedor.com> Date: Wed, 30 Jan 2019 18:33:55 -0600 > 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; > struct boo entry[]; > }; > > instance = kmalloc(sizeof(struct foo) + count * sizeof(struct boo), GFP_KERNEL); > > Instead of leaving these open-coded and prone to type mistakes, we can > now use the new struct_size() helper: > > instance = kmalloc(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> Applied.
diff --git a/drivers/net/ethernet/dec/tulip/eeprom.c b/drivers/net/ethernet/dec/tulip/eeprom.c index 1812f4916917..ba0a69b363f8 100644 --- a/drivers/net/ethernet/dec/tulip/eeprom.c +++ b/drivers/net/ethernet/dec/tulip/eeprom.c @@ -224,9 +224,7 @@ void tulip_parse_eeprom(struct net_device *dev) return; } - mtable = kmalloc(sizeof(struct mediatable) + - count * sizeof(struct medialeaf), - GFP_KERNEL); + mtable = kmalloc(struct_size(mtable, mleaf, count), GFP_KERNEL); if (mtable == NULL) return; /* Horrible, impossible failure. */ last_mediatable = tp->mtable = mtable;
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; struct boo entry[]; }; instance = kmalloc(sizeof(struct foo) + count * sizeof(struct boo), GFP_KERNEL); Instead of leaving these open-coded and prone to type mistakes, we can now use the new struct_size() helper: instance = kmalloc(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/net/ethernet/dec/tulip/eeprom.c | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-)