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 issue was detected with the help of Coccinelle.
Signed-off-by: Gustavo A. R. Silva <gustavo@xxxxxxxxxxxxxx>
---
drivers/net/wireless/intel/iwlwifi/mvm/d3.c | 6 ++----
1 file changed, 2 insertions(+), 4 deletions(-)
diff --git a/drivers/net/wireless/intel/iwlwifi/mvm/d3.c b/drivers/net/wireless/intel/iwlwifi/mvm/d3.c
index 79bdae9..6960318 100644
--- a/drivers/net/wireless/intel/iwlwifi/mvm/d3.c
+++ b/drivers/net/wireless/intel/iwlwifi/mvm/d3.c
@@ -1769,8 +1769,7 @@ static void iwl_mvm_query_netdetect_reasons(struct iwl_mvm *mvm,
n_matches = 0;
}
- net_detect = kzalloc(sizeof(*net_detect) +
- (n_matches * sizeof(net_detect->matches[0])),
+ net_detect = kzalloc(struct_size(net_detect, matches, n_matches),
GFP_KERNEL);
if (!net_detect || !n_matches)
goto out_report_nd;
@@ -1785,8 +1784,7 @@ static void iwl_mvm_query_netdetect_reasons(struct iwl_mvm *mvm,
for (j = 0; j < SCAN_OFFLOAD_MATCHING_CHANNELS_LEN; j++)
n_channels += hweight8(fw_match->matching_channels[j]);
- match = kzalloc(sizeof(*match) +
- (n_channels * sizeof(*match->channels)),
+ match = kzalloc(struct_size(match, channels, n_channels),
GFP_KERNEL);
if (!match)
goto out_report_nd;
--
2.7.4
