From: "Gustavo A. R. Silva" <gustavo@embeddedor.com>
To: Andrew Lunn <andrew@lunn.ch>,
Vivien Didelot <vivien.didelot@gmail.com>,
Florian Fainelli <f.fainelli@gmail.com>,
"David S. Miller" <davem@davemloft.net>
Cc: netdev@vger.kernel.org, linux-kernel@vger.kernel.org,
"Gustavo A. R. Silva" <gustavo@embeddedor.com>
Subject: [PATCH net-next] net: dsa: use struct_size() in devm_kzalloc()
Date: Thu, 7 Feb 2019 19:16:03 -0600 [thread overview]
Message-ID: <20190208011603.GA927@embeddedor> (raw)
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 <gustavo@embeddedor.com>
---
net/dsa/dsa2.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)
diff --git a/net/dsa/dsa2.c b/net/dsa/dsa2.c
index a1917025e155..8c431e0f3627 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;
--
2.20.1
next reply other threads:[~2019-02-08 1:16 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-02-08 1:16 Gustavo A. R. Silva [this message]
2019-02-08 15:32 ` [PATCH net-next] net: dsa: use struct_size() in devm_kzalloc() Vivien Didelot
2019-02-09 6:58 ` David Miller
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