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 regd_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@xxxxxxxxxxxxxx>
---
drivers/net/wireless/marvell/mwifiex/sta_cmdresp.c | 7 ++-----
1 file changed, 2 insertions(+), 5 deletions(-)
diff --git a/drivers/net/wireless/marvell/mwifiex/sta_cmdresp.c b/drivers/net/wireless/marvell/mwifiex/sta_cmdresp.c
index 69e3b624adbb..24b33e20e7a9 100644
--- a/drivers/net/wireless/marvell/mwifiex/sta_cmdresp.c
+++ b/drivers/net/wireless/marvell/mwifiex/sta_cmdresp.c
@@ -1025,17 +1025,14 @@ mwifiex_create_custom_regdomain(struct mwifiex_private *priv,
struct ieee80211_regdomain *regd;
struct ieee80211_reg_rule *rule;
bool new_rule;
- int regd_size, idx, freq, prev_freq = 0;
+ int idx, freq, prev_freq = 0;
u32 bw, prev_bw = 0;
u8 chflags, prev_chflags = 0, valid_rules = 0;
if (WARN_ON_ONCE(num_chan > NL80211_MAX_SUPP_REG_RULES))
return ERR_PTR(-EINVAL);
- regd_size = sizeof(struct ieee80211_regdomain) +
- num_chan * sizeof(struct ieee80211_reg_rule);
-
- regd = kzalloc(regd_size, GFP_KERNEL);
+ regd = kzalloc(struct_size(regd, reg_rules, num_chan), GFP_KERNEL);
if (!regd)
return ERR_PTR(-ENOMEM);
--
2.21.0
