Re: [PATCH] brcmfmac: Replace zero-length array with flexible array member

From: Gustavo A. R. Silva
Date: Sun Sep 12 2021 - 15:12:20 EST


On Sat, Sep 04, 2021 at 11:22:17AM +0200, Len Baker wrote:
> There is a regular need in the kernel to provide a way to declare
> having a dynamically sized set of trailing elements in a structure.
> Kernel code should always use "flexible array members"[1] for these
> cases. The older style of one-element or zero-length arrays should
> no longer be used[2].
>
> Also, make use of the struct_size() helper in devm_kzalloc().
>
> [1] https://en.wikipedia.org/wiki/Flexible_array_member
> [2] https://www.kernel.org/doc/html/v5.14/process/deprecated.html#zero-length-and-one-element-arrays
>
> Signed-off-by: Len Baker <len.baker@xxxxxxx>

Reviewed-by: Gustavo A. R. Silva <gustavoars@xxxxxxxxxx>

I'll take this in my -next tree. :)

Thanks, Len.
--
Gustavo

> ---
> drivers/net/wireless/broadcom/brcm80211/brcmfmac/of.c | 2 +-
> include/linux/platform_data/brcmfmac.h | 2 +-
> 2 files changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/of.c b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/of.c
> index 2f7bc3a70c65..513c7e6421b2 100644
> --- a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/of.c
> +++ b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/of.c
> @@ -29,7 +29,7 @@ static int brcmf_of_get_country_codes(struct device *dev,
> return (count == -EINVAL) ? 0 : count;
> }
>
> - cc = devm_kzalloc(dev, sizeof(*cc) + count * sizeof(*cce), GFP_KERNEL);
> + cc = devm_kzalloc(dev, struct_size(cc, table, count), GFP_KERNEL);
> if (!cc)
> return -ENOMEM;
>
> diff --git a/include/linux/platform_data/brcmfmac.h b/include/linux/platform_data/brcmfmac.h
> index 1d30bf278231..2b5676ff35be 100644
> --- a/include/linux/platform_data/brcmfmac.h
> +++ b/include/linux/platform_data/brcmfmac.h
> @@ -125,7 +125,7 @@ struct brcmfmac_pd_cc_entry {
> */
> struct brcmfmac_pd_cc {
> int table_size;
> - struct brcmfmac_pd_cc_entry table[0];
> + struct brcmfmac_pd_cc_entry table[];
> };
>
> /**
> --
> 2.25.1
>