Re: [PATCH] carl9170: Replace zero-length array of trailing structs with flex-array

From: Christian Lamparter
Date: Fri Nov 18 2022 - 18:09:36 EST


On 11/18/22 22:11, Kees Cook wrote:
Zero-length arrays are deprecated[1] and are being replaced with
flexible array members in support of the ongoing efforts to tighten the
FORTIFY_SOURCE routines on memcpy(), correctly instrument array indexing
with UBSAN_BOUNDS, and to globally enable -fstrict-flex-arrays=3.

Replace zero-length array with flexible-array member.

This results in no differences in binary output.

[1] https://github.com/KSPP/linux/issues/78

Cc: Christian Lamparter <chunkeey@xxxxxxxxxxxxxx>
Cc: Kalle Valo <kvalo@xxxxxxxxxx>
Cc: "David S. Miller" <davem@xxxxxxxxxxxxx>
Cc: Eric Dumazet <edumazet@xxxxxxxxxx>
Cc: Jakub Kicinski <kuba@xxxxxxxxxx>
Cc: Paolo Abeni <pabeni@xxxxxxxxxx>
Cc: "Gustavo A. R. Silva" <gustavoars@xxxxxxxxxx>
Cc: linux-wireless@xxxxxxxxxxxxxxx
Cc: netdev@xxxxxxxxxxxxxxx
Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx>
Acked-by: Christian Lamparter <chunkeey@xxxxxxxxx>

---
drivers/net/wireless/ath/carl9170/fwcmd.h | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/net/wireless/ath/carl9170/fwcmd.h b/drivers/net/wireless/ath/carl9170/fwcmd.h
index 4a500095555c..ff4b3b50250c 100644
--- a/drivers/net/wireless/ath/carl9170/fwcmd.h
+++ b/drivers/net/wireless/ath/carl9170/fwcmd.h
@@ -118,10 +118,10 @@ struct carl9170_reg_list {
} __packed;
struct carl9170_write_reg {
- struct {
+ DECLARE_FLEX_ARRAY(struct {
__le32 addr;
__le32 val;
- } regs[0] __packed;
+ } __packed, regs);
} __packed;
struct carl9170_write_reg_byte {