[PATCH][next] netxen_nic: Replace fake flex-array with flexible-array member

[PATCH][next] netxen_nic: Replace fake flex-array with flexible-array member

[Gustavo A. R. Silva]

Zero-length arrays as fake flexible arrays are deprecated and we are
moving towards adopting C99 flexible-array members instead.

Transform zero-length array into flexible-array member in struct
nx_cardrsp_rx_ctx_t.

Address the following warnings found with GCC-13 and
-fstrict-flex-arrays=3 enabled:
drivers/net/ethernet/qlogic/netxen/netxen_nic_ctx.c:361:26: warning: array subscript <unknown> is outside array bounds of ‘char[0]’ [-Warray-bounds=]
drivers/net/ethernet/qlogic/netxen/netxen_nic_ctx.c:372:25: warning: array subscript <unknown> is outside array bounds of ‘char[0]’ [-Warray-bounds=]

This helps with the ongoing efforts to tighten the FORTIFY_SOURCE
routines on memcpy() and help us make progress towards globally
enabling -fstrict-flex-arrays=3 [1].

Link: https://github.com/KSPP/linux/issues/21
Link: https://github.com/KSPP/linux/issues/265
Link: https://gcc.gnu.org/pipermail/gcc-patches/2022-October/602902.html [1]
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
---
 drivers/net/ethernet/qlogic/netxen/netxen_nic.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/qlogic/netxen/netxen_nic.h b/drivers/net/ethernet/qlogic/netxen/netxen_nic.h
index f13fa7396aef..3d36d23df0c6 100644
--- a/drivers/net/ethernet/qlogic/netxen/netxen_nic.h
+++ b/drivers/net/ethernet/qlogic/netxen/netxen_nic.h
@@ -854,7 +854,7 @@ typedef struct {
 	   The following is packed:
 	   - N cardrsp_rds_rings
 	   - N cardrs_sds_rings */
-	char data[0];
+	char data[];
 } nx_cardrsp_rx_ctx_t;
 
 #define SIZEOF_HOSTRQ_RX(HOSTRQ_RX, rds_rings, sds_rings)	\
-- 
2.34.1

Re: [PATCH][next] netxen_nic: Replace fake flex-array with flexible-array member

[Simon Horman]

On Mon, Mar 06, 2023 at 05:40:28PM -0600, Gustavo A. R. Silva wrote:
> Zero-length arrays as fake flexible arrays are deprecated and we are
> moving towards adopting C99 flexible-array members instead.
> 
> Transform zero-length array into flexible-array member in struct
> nx_cardrsp_rx_ctx_t.
> 
> Address the following warnings found with GCC-13 and
> -fstrict-flex-arrays=3 enabled:
> drivers/net/ethernet/qlogic/netxen/netxen_nic_ctx.c:361:26: warning: array subscript <unknown> is outside array bounds of ‘char[0]’ [-Warray-bounds=]
> drivers/net/ethernet/qlogic/netxen/netxen_nic_ctx.c:372:25: warning: array subscript <unknown> is outside array bounds of ‘char[0]’ [-Warray-bounds=]
> 
> This helps with the ongoing efforts to tighten the FORTIFY_SOURCE
> routines on memcpy() and help us make progress towards globally
> enabling -fstrict-flex-arrays=3 [1].
> 
> Link: https://github.com/KSPP/linux/issues/21
> Link: https://github.com/KSPP/linux/issues/265
> Link: https://gcc.gnu.org/pipermail/gcc-patches/2022-October/602902.html [1]
> Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>

Reviewed-by: Simon Horman <simon.horman@corigine.com>