watchdog: cros-ec: Avoid -Wflex-array-member-not-at-end warning

-Wflex-array-member-not-at-end was introduced in GCC-14, and we are
getting ready to enable it, globally.

Use the `DEFINE_RAW_FLEX()` helper for on-stack definitions of
a flexible structure where the size of the flexible-array member
is known at compile-time, and refactor the rest of the code,
accordingly.

So, with these changes, fix the following warning:

drivers/watchdog/cros_ec_wdt.c:29:40: warning: structure containing a flexible array member is not at the end of another structure [-Wflex-array-member-not-at-end]

Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Reviewed-by: Tzung-Bi Shih <tzungbi@kernel.org>
Reviewed-by: Kees Cook <kees@kernel.org>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Link: https://lore.kernel.org/r/Z-WG6_uhWsy_FCq3@kspp
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@linux-watchdog.org>

diff --git a/drivers/watchdog/cros_ec_wdt.c b/drivers/watchdog/cros_ec_wdt.c
index 716c23f4388ca365ab004da5cf02140d4a4402d2..9ffe7f5056453f6b5e54f9397a70aa596e220654 100644 (file)
--- a/drivers/watchdog/cros_ec_wdt.c
+++ b/drivers/watchdog/cros_ec_wdt.c
@@ -25,26 +25,22 @@ static int cros_ec_wdt_send_cmd(struct cros_ec_device *cros_ec,
                                union cros_ec_wdt_data *arg)
 {
        int ret;
-       struct {
-               struct cros_ec_command msg;
-               union cros_ec_wdt_data data;
-       } __packed buf = {
-               .msg = {
-                       .version = 0,
-                       .command = EC_CMD_HANG_DETECT,
-                       .insize  = (arg->req.command == EC_HANG_DETECT_CMD_GET_STATUS) ?
-                                  sizeof(struct ec_response_hang_detect) :
-                                  0,
-                       .outsize = sizeof(struct ec_params_hang_detect),
-               },
-               .data.req = arg->req
-       };
-
-       ret = cros_ec_cmd_xfer_status(cros_ec, &buf.msg);
+       DEFINE_RAW_FLEX(struct cros_ec_command, msg, data,
+                       sizeof(union cros_ec_wdt_data));
+
+       msg->version = 0;
+       msg->command = EC_CMD_HANG_DETECT;
+       msg->insize  = (arg->req.command == EC_HANG_DETECT_CMD_GET_STATUS) ?
+                  sizeof(struct ec_response_hang_detect) :
+                  0;
+       msg->outsize = sizeof(struct ec_params_hang_detect);
+       *(struct ec_params_hang_detect *)msg->data = arg->req;
+
+       ret = cros_ec_cmd_xfer_status(cros_ec, msg);
        if (ret < 0)
                return ret;
 
-       arg->resp = buf.data.resp;
+       arg->resp = *(struct ec_response_hang_detect *)msg->data;
 
        return 0;
 }