diff mbox series

[next] iwlwifi: mvm: use struct_size() in kzalloc()

Message ID 20190115220246.GA23339@embeddedor
State Awaiting Upstream
Delegated to: David Miller
Headers show
Series [next] iwlwifi: mvm: use struct_size() in kzalloc() | expand

Commit Message

Gustavo A. R. Silva Jan. 15, 2019, 10:02 p.m. UTC
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[];
};

instance = kzalloc(sizeof(struct foo) + count * sizeof(struct boo), 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@embeddedor.com>
---
 drivers/net/wireless/intel/iwlwifi/iwl-nvm-parse.c | 14 +++++---------
 1 file changed, 5 insertions(+), 9 deletions(-)

Comments

Coelho, Luciano Jan. 22, 2019, 10:57 a.m. UTC | #1
On Tue, 2019-01-15 at 16:02 -0600, Gustavo A. R. Silva wrote:
> 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[];
> };
> 
> instance = kzalloc(sizeof(struct foo) + count * sizeof(struct boo),
> 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@embeddedor.com>
> ---

Dropped.  This is a duplicate.

--
Luca.
diff mbox series

Patch

diff --git a/drivers/net/wireless/intel/iwlwifi/iwl-nvm-parse.c b/drivers/net/wireless/intel/iwlwifi/iwl-nvm-parse.c
index d9afedc3d1d9..a2b2bdc5cd09 100644
--- a/drivers/net/wireless/intel/iwlwifi/iwl-nvm-parse.c
+++ b/drivers/net/wireless/intel/iwlwifi/iwl-nvm-parse.c
@@ -947,14 +947,12 @@  iwl_parse_nvm_data(struct iwl_trans *trans, const struct iwl_cfg *cfg,
 	const __le16 *ch_section;
 
 	if (cfg->nvm_type != IWL_NVM_EXT)
-		data = kzalloc(sizeof(*data) +
-			       sizeof(struct ieee80211_channel) *
-			       IWL_NVM_NUM_CHANNELS,
+		data = kzalloc(struct_size(data, channels,
+			       IWL_NVM_NUM_CHANNELS),
 			       GFP_KERNEL);
 	else
-		data = kzalloc(sizeof(*data) +
-			       sizeof(struct ieee80211_channel) *
-			       IWL_NVM_NUM_CHANNELS_EXT,
+		data = kzalloc(struct_size(data, channels,
+			       IWL_NVM_NUM_CHANNELS_EXT),
 			       GFP_KERNEL);
 	if (!data)
 		return NULL;
@@ -1444,9 +1442,7 @@  struct iwl_nvm_data *iwl_get_nvm(struct iwl_trans *trans,
 	if (empty_otp)
 		IWL_INFO(trans, "OTP is empty\n");
 
-	nvm = kzalloc(sizeof(*nvm) +
-		      sizeof(struct ieee80211_channel) * IWL_NUM_CHANNELS,
-		      GFP_KERNEL);
+	nvm = kzalloc(struct_size(nvm, channels, IWL_NUM_CHANNELS), GFP_KERNEL);
 	if (!nvm) {
 		ret = -ENOMEM;
 		goto out;