| Message ID | 20190108175519.GA8878@embeddedor (mailing list archive) |
|---|---|
| State | Accepted |
| Delegated to: | Luca Coelho |
| Headers | show |
| Series | iwlwifi: nvm-parse: use struct_size() in kzalloc() | expand |
On Tue, 2019-01-08 at 11:55 -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; > 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@embeddedor.com> > --- Thanks! I applied this to our internal tree and it will reach the mainline following our normal upstreaming process. -- Cheers, Luca.
diff --git a/drivers/net/wireless/intel/iwlwifi/iwl-nvm-parse.c b/drivers/net/wireless/intel/iwlwifi/iwl-nvm-parse.c index d9afedc3d1d9..8c720b42dc36 100644 --- a/drivers/net/wireless/intel/iwlwifi/iwl-nvm-parse.c +++ b/drivers/net/wireless/intel/iwlwifi/iwl-nvm-parse.c @@ -947,15 +947,13 @@ 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, - GFP_KERNEL); + 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, - GFP_KERNEL); + 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;
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@embeddedor.com> --- .../net/wireless/intel/iwlwifi/iwl-nvm-parse.c | 18 +++++++----------- 1 file changed, 7 insertions(+), 11 deletions(-)