From 9a1ace64ca3b713e1029fed83dc22d8740b20aba Mon Sep 17 00:00:00 2001 From: "Gustavo A. R. Silva" Date: Fri, 7 Jun 2019 14:17:45 -0500 Subject: [PATCH] qtnfmac: 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 ieee80211_regdomain { ... struct ieee80211_reg_rule reg_rules[]; }; instance = kzalloc(sizeof(*mac->rd) + sizeof(struct ieee80211_reg_rule) * count, 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, reg_rules, count), GFP_KERNEL); This code was detected with the help of Coccinelle. Signed-off-by: Gustavo A. R. Silva Reviewed-by: Sergey Matyukevich Signed-off-by: Kalle Valo --- drivers/net/wireless/quantenna/qtnfmac/commands.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) diff --git a/drivers/net/wireless/quantenna/qtnfmac/commands.c b/drivers/net/wireless/quantenna/qtnfmac/commands.c index 459f6b81d2eb..dc0c7244b60e 100644 --- a/drivers/net/wireless/quantenna/qtnfmac/commands.c +++ b/drivers/net/wireless/quantenna/qtnfmac/commands.c @@ -1011,9 +1011,8 @@ qtnf_parse_variable_mac_info(struct qtnf_wmac *mac, if (WARN_ON(resp->n_reg_rules > NL80211_MAX_SUPP_REG_RULES)) return -E2BIG; - mac->rd = kzalloc(sizeof(*mac->rd) + - sizeof(struct ieee80211_reg_rule) * - resp->n_reg_rules, GFP_KERNEL); + mac->rd = kzalloc(struct_size(mac->rd, reg_rules, resp->n_reg_rules), + GFP_KERNEL); if (!mac->rd) return -ENOMEM; -- 2.11.0