From: Gustavo A. R. Silva Date: Thu, 8 Aug 2024 22:11:15 +0000 (-0600) Subject: wifi: mwl8k: Use static_assert() to check struct sizes X-Git-Tag: v6.12-rc1~232^2~101^2~70 X-Git-Url: https://git.kernel.dk/?a=commitdiff_plain;h=748e21d94a34edc6e74e9ec674e93e570d3d0d3e;p=linux-block.git wifi: mwl8k: Use static_assert() to check struct sizes Commit 5c4250092fad ("wifi: mwl8k: Avoid -Wflex-array-member-not-at-end warnings") introduced tagged `struct mwl8k_cmd_pkt_hdr`. We want to ensure that when new members need to be added to the flexible structure, they are always included within this tagged struct. We use `static_assert()` to ensure that the memory layout for both the flexible structure and the tagged struct is the same after any changes. Signed-off-by: Gustavo A. R. Silva Signed-off-by: Kalle Valo Link: https://patch.msgid.link/ZrVCg51Q9M2fTPaF@cute --- diff --git a/drivers/net/wireless/marvell/mwl8k.c b/drivers/net/wireless/marvell/mwl8k.c index b130e057370f..bab9ef37a1ab 100644 --- a/drivers/net/wireless/marvell/mwl8k.c +++ b/drivers/net/wireless/marvell/mwl8k.c @@ -587,6 +587,7 @@ static int mwl8k_request_firmware(struct mwl8k_priv *priv, char *fw_image, } struct mwl8k_cmd_pkt { + /* New members MUST be added within the __struct_group() macro below. */ __struct_group(mwl8k_cmd_pkt_hdr, hdr, __packed, __le16 code; __le16 length; @@ -596,6 +597,8 @@ struct mwl8k_cmd_pkt { ); char payload[]; } __packed; +static_assert(offsetof(struct mwl8k_cmd_pkt, payload) == sizeof(struct mwl8k_cmd_pkt_hdr), + "struct member likely outside of __struct_group()"); /* * Firmware loading.