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cfg80211: Use struct_size() in 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 = kzalloc(size, GFP_KERNEL)

Instead of leaving these open-coded and prone to type mistakes, we can
now use the new struct_size() helper:

instance = kzalloc(struct_size(instance, entry, count), GFP_KERNEL)

Notice that, in this case, variable size_of_regd 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>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
This commit is contained in:
Gustavo A. R. Silva 2019-04-03 10:31:51 -05:00 committed by Johannes Berg
parent 276d9e82e0
commit 9f8c7136e8
1 changed files with 7 additions and 16 deletions
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23
net/wireless/reg.c
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@ -427,14 +427,10 @@ static const struct ieee80211_regdomain *
reg_copy_regd(const struct ieee80211_regdomain *src_regd)
{
struct ieee80211_regdomain *regd;
int size_of_regd;
unsigned int i;
size_of_regd =
sizeof(struct ieee80211_regdomain) +
src_regd->n_reg_rules * sizeof(struct ieee80211_reg_rule);
regd = kzalloc(size_of_regd, GFP_KERNEL);
regd = kzalloc(struct_size(regd, reg_rules, src_regd->n_reg_rules),
GFP_KERNEL);
if (!regd)
return ERR_PTR(-ENOMEM);
@ -948,12 +944,10 @@ static int regdb_query_country(const struct fwdb_header *db,
unsigned int ptr = be16_to_cpu(country->coll_ptr) << 2;
struct fwdb_collection *coll = (void *)((u8 *)db + ptr);
struct ieee80211_regdomain *regdom;
unsigned int size_of_regd, i;
unsigned int i;
size_of_regd = sizeof(struct ieee80211_regdomain) +
coll->n_rules * sizeof(struct ieee80211_reg_rule);
regdom = kzalloc(size_of_regd, GFP_KERNEL);
regdom = kzalloc(struct_size(regdom, reg_rules, coll->n_rules),
GFP_KERNEL);
if (!regdom)
return -ENOMEM;
@ -1450,7 +1444,7 @@ static struct ieee80211_regdomain *
regdom_intersect(const struct ieee80211_regdomain *rd1,
const struct ieee80211_regdomain *rd2)
{
int r, size_of_regd;
int r;
unsigned int x, y;
unsigned int num_rules = 0;
const struct ieee80211_reg_rule *rule1, *rule2;
@ -1481,10 +1475,7 @@ regdom_intersect(const struct ieee80211_regdomain *rd1,
if (!num_rules)
return NULL;
size_of_regd = sizeof(struct ieee80211_regdomain) +
num_rules * sizeof(struct ieee80211_reg_rule);
rd = kzalloc(size_of_regd, GFP_KERNEL);
rd = kzalloc(struct_size(rd, reg_rules, num_rules), GFP_KERNEL);
if (!rd)
return NULL;