From: Gustavo A. R. Silva Date: Fri, 8 Feb 2019 01:16:03 +0000 (-0600) Subject: net: dsa: use struct_size() in devm_kzalloc() X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=33b363e004fdb6abf12a5b0c51dc2c221d352cac;p=linux.git net: dsa: use struct_size() in devm_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; struct boo entry[]; }; size = sizeof(struct foo) + count * sizeof(struct boo); instance = alloc(size, GFP_KERNEL) Instead of leaving these open-coded and prone to type mistakes, we can now use the new struct_size() helper: instance = alloc(struct_size(instance, entry, count), GFP_KERNEL) Notice that, in this case, variable size is not necessary, hence it is removed. This code was detected with the help of Coccinelle. Signed-off-by: Gustavo A. R. Silva Reviewed-by: Vivien Didelot Signed-off-by: David S. Miller --- diff --git a/net/dsa/dsa2.c b/net/dsa/dsa2.c index a1917025e155b..8c431e0f36278 100644 --- a/net/dsa/dsa2.c +++ b/net/dsa/dsa2.c @@ -767,11 +767,10 @@ static int dsa_switch_probe(struct dsa_switch *ds) struct dsa_switch *dsa_switch_alloc(struct device *dev, size_t n) { - size_t size = sizeof(struct dsa_switch) + n * sizeof(struct dsa_port); struct dsa_switch *ds; int i; - ds = devm_kzalloc(dev, size, GFP_KERNEL); + ds = devm_kzalloc(dev, struct_size(ds, ports, n), GFP_KERNEL); if (!ds) return NULL;