wifi: rtw89: use flexible array member in rtw89_btc_btf_tlv

struct rtw89_btc_btf_tlv contains a one-byte member that is intended as a
flexible array:

In function 'fortify_memcpy_chk',
    inlined from '_append_tdma' at drivers/net/wireless/realtek/rtw89/coex.c:1579:3:
include/linux/fortify-string.h:583:25: error: call to '__write_overflow_field' declared with attribute warning: detected write beyond size of field (1st parameter); maybe use struct_group()? [-Werror=attribute-warning]
  583 |                         __write_overflow_field(p_size_field, size);
      |                         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Make this actually use a flexible array to let the compiler understand.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Ping-Ke Shih <pkshih@realtek.com>
Reviewed-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Signed-off-by: Kalle Valo <kvalo@kernel.org>
Link: https://lore.kernel.org/r/20230523113241.2772811-1-arnd@kernel.org

diff --git a/drivers/net/wireless/realtek/rtw89/coex.c b/drivers/net/wireless/realtek/rtw89/coex.c
index 3a586a971e8f040c8dffcf14c9fcebdc93276fb2..bda0e1e99a8c6b636199b194a23222e0428d83ce 100644 (file)
--- a/drivers/net/wireless/realtek/rtw89/coex.c
+++ b/drivers/net/wireless/realtek/rtw89/coex.c
@@ -206,7 +206,7 @@ static const struct rtw89_btc_ver rtw89_btc_ver_defs[] = {
 struct rtw89_btc_btf_tlv {
        u8 type;
        u8 len;
-       u8 val[1];
+       u8 val[];
 } __packed;
 
 enum btc_btf_set_report_en {