[PATCH][next] can: ucan: Replace zero-length array with DECLARE_FLEX_ARRAY() helper

From: "Gustavo A. R. Silva" <gustavoars@kernel.org>
To: Wolfgang Grandegger <wg@grandegger.com>,
	Marc Kleine-Budde <mkl@pengutronix.de>,
	"David S. Miller" <davem@davemloft.net>,
	Eric Dumazet <edumazet@google.com>,
	Jakub Kicinski <kuba@kernel.org>, Paolo Abeni <pabeni@redhat.com>
Cc: linux-can@vger.kernel.org, netdev@vger.kernel.org,
	linux-kernel@vger.kernel.org,
	"Gustavo A. R. Silva" <gustavoars@kernel.org>,
	linux-hardening@vger.kernel.org
Subject: [PATCH][next] can: ucan: Replace zero-length array with DECLARE_FLEX_ARRAY() helper
Date: Mon, 26 Sep 2022 16:43:56 -0500	[thread overview]
Message-ID: <YzIdHDdz30BH4SAv@work> (raw)

Zero-length arrays are deprecated and we are moving towards adopting
C99 flexible-array members, instead. So, replace zero-length arrays
declarations in anonymous union with the new DECLARE_FLEX_ARRAY()
helper macro.

This helper allows for flexible-array members in unions.

Link: https://github.com/KSPP/linux/issues/193
Link: https://github.com/KSPP/linux/issues/214
Link: https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
---
 drivers/net/can/usb/ucan.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/net/can/usb/ucan.c b/drivers/net/can/usb/ucan.c
index 7c35f50fda4e..b53e709943bc 100644
--- a/drivers/net/can/usb/ucan.c
+++ b/drivers/net/can/usb/ucan.c
@@ -245,7 +245,8 @@ struct ucan_message_in {
 		/* CAN transmission complete
 		 * (type == UCAN_IN_TX_COMPLETE)
 		 */
-		struct ucan_tx_complete_entry_t can_tx_complete_msg[0];
+		DECLARE_FLEX_ARRAY(struct ucan_tx_complete_entry_t,
+				   can_tx_complete_msg);
 	} __aligned(0x4) msg;
 } __packed __aligned(0x4);
 
-- 
2.34.1

