[PATCH][next] carl9170: Replace zero-length arrays with flexible-array members

[PATCH][next] carl9170: Replace zero-length arrays with flexible-array members

[Gustavo A. R. Silva]

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].

[1] https://en.wikipedia.org/wiki/Flexible_array_member
[2] https://www.kernel.org/doc/html/v5.16/process/deprecated.html#zero-length-and-one-element-arrays

Link: https://github.com/KSPP/linux/issues/78
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
---
 drivers/net/wireless/ath/carl9170/fwdesc.h | 2 +-
 drivers/net/wireless/ath/carl9170/wlan.h   | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/net/wireless/ath/carl9170/fwdesc.h b/drivers/net/wireless/ath/carl9170/fwdesc.h
index 503b21abbba5..10acb6ad30d0 100644
--- a/drivers/net/wireless/ath/carl9170/fwdesc.h
+++ b/drivers/net/wireless/ath/carl9170/fwdesc.h
@@ -149,7 +149,7 @@ struct carl9170fw_fix_entry {
 
 struct carl9170fw_fix_desc {
 	struct carl9170fw_desc_head head;
-	struct carl9170fw_fix_entry data[0];
+	struct carl9170fw_fix_entry data[];
 } __packed;
 #define CARL9170FW_FIX_DESC_SIZE			\
 	(sizeof(struct carl9170fw_fix_desc))
diff --git a/drivers/net/wireless/ath/carl9170/wlan.h b/drivers/net/wireless/ath/carl9170/wlan.h
index bb73553fd7c2..0a4e42e806b9 100644
--- a/drivers/net/wireless/ath/carl9170/wlan.h
+++ b/drivers/net/wireless/ath/carl9170/wlan.h
@@ -327,7 +327,7 @@ struct _carl9170_tx_superdesc {
 struct _carl9170_tx_superframe {
 	struct _carl9170_tx_superdesc s;
 	struct _ar9170_tx_hwdesc f;
-	u8 frame_data[0];
+	u8 frame_data[];
 } __packed __aligned(4);
 
 #define	CARL9170_TX_SUPERDESC_LEN		24
-- 
2.27.0

Re: [PATCH][next] carl9170: Replace zero-length arrays with flexible-array members

[Kees Cook]

On Wed, Feb 16, 2022 at 01:49:55PM -0600, Gustavo A. R. Silva 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].
> 
> [1] https://en.wikipedia.org/wiki/Flexible_array_member
> [2] https://www.kernel.org/doc/html/v5.16/process/deprecated.html#zero-length-and-one-element-arrays
> 
> Link: https://github.com/KSPP/linux/issues/78
> Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>

Reviewed-by: Kees Cook <keescook@chromium.org>

-- 
Kees Cook

Re: [PATCH][next] carl9170: Replace zero-length arrays with flexible-array members

[Christian Lamparter]

On 16/02/2022 20:49, Gustavo A. R. Silva 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].
> 
> [1] https://en.wikipedia.org/wiki/Flexible_array_member
> [2] https://www.kernel.org/doc/html/v5.16/process/deprecated.html#zero-length-and-one-element-arrays
> 
> Link: https://github.com/KSPP/linux/issues/78
> Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>

Acked-by: Christian Lamparter <chunkeey@gmail.com>

(I've also applied it to the firmware source)

Re: [PATCH][next] carl9170: Replace zero-length arrays with flexible-array members

[Kalle Valo]

"Gustavo A. R. Silva" <gustavoars@kernel.org> 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].
> 
> [1] https://en.wikipedia.org/wiki/Flexible_array_member
> [2] https://www.kernel.org/doc/html/v5.16/process/deprecated.html#zero-length-and-one-element-arrays
> 
> Link: https://github.com/KSPP/linux/issues/78
> Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
> Reviewed-by: Kees Cook <keescook@chromium.org>
> Acked-by: Christian Lamparter <chunkeey@gmail.com>
> Signed-off-by: Kalle Valo <quic_kvalo@quicinc.com>

Patch applied to ath-next branch of ath.git, thanks.

152094dd8c8d carl9170: Replace zero-length arrays with flexible-array members

-- 
https://patchwork.kernel.org/project/linux-wireless/patch/20220216194955.GA904126@embeddedor/

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