tulip: eeprom: use struct_size() in kmalloc()
authorGustavo A. R. Silva <gustavo@embeddedor.com>
Thu, 31 Jan 2019 00:33:55 +0000 (18:33 -0600)
committerDavid S. Miller <davem@davemloft.net>
Fri, 1 Feb 2019 23:12:29 +0000 (15:12 -0800)
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>
Signed-off-by: David S. Miller <davem@davemloft.net>
drivers/net/ethernet/dec/tulip/eeprom.c

index 1812f4916917e41ee58e42170444aa38a199a19f..ba0a69b363f83767838666c82d0131a7bcae658c 100644 (file)
@@ -224,9 +224,7 @@ subsequent_board:
                        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;