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;
void *entry[];
};
instance = kzalloc(sizeof(struct foo) + sizeof(void *) * 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, entry, count), GFP_KERNEL);
This code was detected with the help of Coccinelle.
Signed-off-by: Gustavo A. R. Silva <gustavo@xxxxxxxxxxxxxx>
---
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 659e7649fe22..cf386f579060 100644
--- a/drivers/net/wireless/quantenna/qtnfmac/commands.c
+++ b/drivers/net/wireless/quantenna/qtnfmac/commands.c
@@ -914,9 +914,8 @@ qtnf_cmd_resp_proc_hw_info(struct qtnf_bus *bus,
if (WARN_ON(resp->n_reg_rules > NL80211_MAX_SUPP_REG_RULES))
return -E2BIG;
- hwinfo->rd = kzalloc(sizeof(*hwinfo->rd)
- + sizeof(struct ieee80211_reg_rule)
- * resp->n_reg_rules, GFP_KERNEL);
+ hwinfo->rd = kzalloc(struct_size(hwinfo->rd, reg_rules,
+ resp->n_reg_rules), GFP_KERNEL);
if (!hwinfo->rd)
return -ENOMEM;
--
2.20.1
