From 391d132cbedbe9b454f8a12544cb12b0df8d4e5b Mon Sep 17 00:00:00 2001 From: "Gustavo A. R. Silva" Date: Wed, 3 Apr 2019 10:37:44 -0500 Subject: nl80211: 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 Signed-off-by: Johannes Berg --- net/wireless/nl80211.c | 10 +++------- 1 file changed, 3 insertions(+), 7 deletions(-) (limited to 'net/wireless') diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c index e7984f025bc7..64f191244c67 100644 --- a/net/wireless/nl80211.c +++ b/net/wireless/nl80211.c @@ -3876,8 +3876,7 @@ static struct cfg80211_acl_data *parse_acl_data(struct wiphy *wiphy, if (n_entries > wiphy->max_acl_mac_addrs) return ERR_PTR(-ENOTSUPP); - acl = kzalloc(sizeof(*acl) + (sizeof(struct mac_address) * n_entries), - GFP_KERNEL); + acl = kzalloc(struct_size(acl, mac_addrs, n_entries), GFP_KERNEL); if (!acl) return ERR_PTR(-ENOMEM); @@ -6916,7 +6915,7 @@ static int nl80211_set_reg(struct sk_buff *skb, struct genl_info *info) struct nlattr *nl_reg_rule; char *alpha2; int rem_reg_rules, r; - u32 num_rules = 0, rule_idx = 0, size_of_regd; + u32 num_rules = 0, rule_idx = 0; enum nl80211_dfs_regions dfs_region = NL80211_DFS_UNSET; struct ieee80211_regdomain *rd; @@ -6941,10 +6940,7 @@ static int nl80211_set_reg(struct sk_buff *skb, struct genl_info *info) if (!reg_is_valid_request(alpha2)) return -EINVAL; - 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 -ENOMEM; -- cgit v1.2.3-59-g8ed1b