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SubjectRe: [PATCH net-next] nfp: use struct_size() in kzalloc()
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On Wed, 2019-01-30 at 18:38 -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.

Might be useful to augment the script to include cases
where the computed size is saved to a temporary and
that temporary is used ala:

https://patchwork.kernel.org/patch/10782453/

On Sat, 2019-01-26 at 20:42 +0800, YueHaibing wrote:
> Use kmemdup rather than duplicating its implementation
[]
> diff --git a/drivers/net/wireless/intel/iwlwifi/iwl-nvm-parse.c b/drivers/net/wireless/intel/iwlwifi/iwl-nvm-parse.c
[]
> @@ -1196,13 +1196,9 @@ iwl_parse_nvm_mcc_info(struct device *dev, const struct iwl_cfg *cfg,
> regd_to_copy = sizeof(struct ieee80211_regdomain) +
> valid_rules * sizeof(struct ieee80211_reg_rule);
> - copy_rd = kzalloc(regd_to_copy, GFP_KERNEL);
> - if (!copy_rd) {
> + copy_rd = kmemdup(regd, regd_to_copy, GFP_KERNEL);

This should probably be

copy_rd = kmemdup(regd, struct_size(regd, reg_rules, valid_rules),
GFP_KERNEL);



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