Re: [PATCH v2][next] leds: Avoid -Wflex-array-member-not-at-end warning

From: Thomas Weißschuh
Date: Mon Mar 31 2025 - 14:01:53 EST


On 2025-03-31 11:01:38-0600, Gustavo A. R. Silva wrote:
> -Wflex-array-member-not-at-end was introduced in GCC-14, and we are
> getting ready to enable it, globally.
>
> Replace an on-stack definition of a flexible structure with a call
> to utility function cros_ec_cmd().
>
> So, with these changes, fix the following warning:
>
> drivers/leds/leds-cros_ec.c:70:40: 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@xxxxxxxxxx>

Thanks!

Acked-by: Thomas Weißschuh <linux@xxxxxxxxxxxxxx>

> ---
> Changes in v2:
> - Use utility function cros_ec_cmd() instead of DEFINE_RAW_FLEX(). (Thomas Weißschuh)
>
> v1:
> - Link: https://lore.kernel.org/linux-hardening/Z-azMlPnP7nPPJrY@kspp/
>
> drivers/leds/leds-cros_ec.c | 21 ++++-----------------
> 1 file changed, 4 insertions(+), 17 deletions(-)
>
> diff --git a/drivers/leds/leds-cros_ec.c b/drivers/leds/leds-cros_ec.c
> index 275522b81ea5..377cf04e202a 100644
> --- a/drivers/leds/leds-cros_ec.c
> +++ b/drivers/leds/leds-cros_ec.c
> @@ -60,31 +60,18 @@ static inline struct cros_ec_led_priv *cros_ec_led_cdev_to_priv(struct led_class
> union cros_ec_led_cmd_data {
> struct ec_params_led_control req;
> struct ec_response_led_control resp;
> -} __packed;
> +};
>
> static int cros_ec_led_send_cmd(struct cros_ec_device *cros_ec,
> union cros_ec_led_cmd_data *arg)
> {
> int ret;
> - struct {
> - struct cros_ec_command msg;
> - union cros_ec_led_cmd_data data;
> - } __packed buf = {
> - .msg = {
> - .version = 1,
> - .command = EC_CMD_LED_CONTROL,
> - .insize = sizeof(arg->resp),
> - .outsize = sizeof(arg->req),
> - },
> - .data.req = arg->req
> - };
> -
> - ret = cros_ec_cmd_xfer_status(cros_ec, &buf.msg);
> +
> + ret = cros_ec_cmd(cros_ec, 1, EC_CMD_LED_CONTROL, &arg->req,
> + sizeof(arg->req), &arg->resp, sizeof(arg->resp));
> if (ret < 0)
> return ret;
>
> - arg->resp = buf.data.resp;
> -
> return 0;
> }
>
> --
> 2.43.0
>