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

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 <redacted>
---
 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

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 <redacted>

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

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

Thanks, Len.
--
Gustavo

Len Baker [off-list ref] 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 <redacted>
Reviewed-by: Gustavo A. R. Silva <gustavoars@kernel.org>

Patch applied to wireless-drivers-next.git, thanks.

3fd445a4d49f brcmfmac: Replace zero-length array with flexible array member

-- 
https://patchwork.kernel.org/project/linux-wireless/patch/20210904092217.2848-1-len.baker@gmx.com/

https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches