From 9f8c7136e8aa92a334ef2fc92dd6b5bbd23886da Mon Sep 17 00:00:00 2001 From: "Gustavo A. R. Silva" Date: Wed, 3 Apr 2019 10:31:51 -0500 Subject: [PATCH] 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 Signed-off-by: Johannes Berg --- net/wireless/reg.c | 23 +++++++---------------- 1 file changed, 7 insertions(+), 16 deletions(-) diff --git a/net/wireless/reg.c b/net/wireless/reg.c index 2f1bf91eb226..0d5b11d7c6ed 100644 --- a/net/wireless/reg.c +++ b/net/wireless/reg.c @@ -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; - - size_of_regd = sizeof(struct ieee80211_regdomain) + - coll->n_rules * sizeof(struct ieee80211_reg_rule); + unsigned int i; - 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; -- 2.30.2