lkml.org 
[lkml]   [2019]   [Feb]   [7]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
Date
From
Subject[PATCH net-next] 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 <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
\
 
 \ /
  Last update: 2019-02-08 02:16    [W:0.130 / U:0.336 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site