* Re: [PATCH v2][next] watchdog: cros-ec: Avoid -Wflex-array-member-not-at-end warning
2025-03-27 17:12 [PATCH v2][next] watchdog: cros-ec: Avoid -Wflex-array-member-not-at-end warning Gustavo A. R. Silva
@ 2025-03-28 4:41 ` Guenter Roeck
2025-04-07 19:13 ` Kees Cook
2025-04-16 0:24 ` Gustavo A. R. Silva
2 siblings, 0 replies; 6+ messages in thread
From: Guenter Roeck @ 2025-03-28 4:41 UTC (permalink / raw)
To: Gustavo A. R. Silva, Lukasz Majczak, Wim Van Sebroeck,
Benson Leung, Tzung-Bi Shih
Cc: chrome-platform, linux-watchdog, linux-kernel, linux-hardening
On 3/27/25 10:12, 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.
>
> 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]
>
> Reviewed-by: Tzung-Bi Shih <tzungbi@kernel.org>
> Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH v2][next] watchdog: cros-ec: Avoid -Wflex-array-member-not-at-end warning
2025-03-27 17:12 [PATCH v2][next] watchdog: cros-ec: Avoid -Wflex-array-member-not-at-end warning Gustavo A. R. Silva
2025-03-28 4:41 ` Guenter Roeck
@ 2025-04-07 19:13 ` Kees Cook
2025-04-07 19:42 ` Gustavo A. R. Silva
2025-04-16 0:24 ` Gustavo A. R. Silva
2 siblings, 1 reply; 6+ messages in thread
From: Kees Cook @ 2025-04-07 19:13 UTC (permalink / raw)
To: Gustavo A. R. Silva
Cc: Lukasz Majczak, Wim Van Sebroeck, Guenter Roeck, Benson Leung,
Tzung-Bi Shih, chrome-platform, linux-watchdog, linux-kernel,
linux-hardening
On Thu, Mar 27, 2025 at 11:12:11AM -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.
>
> 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]
>
> Reviewed-by: Tzung-Bi Shih <tzungbi@kernel.org>
> Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
> ---
> Changes v2:
> - Fix truncated line in changelog text. (Tzung-Bi)
> - Update variable name: s/buf/msg (Tzung-Bi)
> - Cast to structs instead of union. (Tzung-Bi)
> - Add RB tag.
>
> v1:
> - Link: https://lore.kernel.org/linux-hardening/Z-SBITmMfwjocYwL@kspp/
>
> drivers/watchdog/cros_ec_wdt.c | 30 +++++++++++++-----------------
> 1 file changed, 13 insertions(+), 17 deletions(-)
>
> diff --git a/drivers/watchdog/cros_ec_wdt.c b/drivers/watchdog/cros_ec_wdt.c
> index 716c23f4388c..9ffe7f505645 100644
> --- 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;
Technically redundant, but it was redundant before, so keeping style is
okay.
> + 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;
msg->data used twice and a "sizeof()" earlier... might be nicer to have
an explicit pointer?
-Kees
>
> return 0;
> }
> --
> 2.43.0
>
--
Kees Cook
^ permalink raw reply [flat|nested] 6+ messages in thread* Re: [PATCH v2][next] watchdog: cros-ec: Avoid -Wflex-array-member-not-at-end warning
2025-04-07 19:13 ` Kees Cook
@ 2025-04-07 19:42 ` Gustavo A. R. Silva
2025-04-07 20:36 ` Kees Cook
0 siblings, 1 reply; 6+ messages in thread
From: Gustavo A. R. Silva @ 2025-04-07 19:42 UTC (permalink / raw)
To: Kees Cook, Gustavo A. R. Silva
Cc: Lukasz Majczak, Wim Van Sebroeck, Guenter Roeck, Benson Leung,
Tzung-Bi Shih, chrome-platform, linux-watchdog, linux-kernel,
linux-hardening
>
>> + 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;
>
> msg->data used twice and a "sizeof()" earlier... might be nicer to have
> an explicit pointer?
Those are two different pointers:
*(struct ec_params_hang_detect *)msg->data = arg->req;
arg->resp = *(struct ec_response_hang_detect *)msg->data;
--
Gustavo
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH v2][next] watchdog: cros-ec: Avoid -Wflex-array-member-not-at-end warning
2025-04-07 19:42 ` Gustavo A. R. Silva
@ 2025-04-07 20:36 ` Kees Cook
0 siblings, 0 replies; 6+ messages in thread
From: Kees Cook @ 2025-04-07 20:36 UTC (permalink / raw)
To: Gustavo A. R. Silva
Cc: Gustavo A. R. Silva, Lukasz Majczak, Wim Van Sebroeck,
Guenter Roeck, Benson Leung, Tzung-Bi Shih, chrome-platform,
linux-watchdog, linux-kernel, linux-hardening
On Mon, Apr 07, 2025 at 01:42:07PM -0600, Gustavo A. R. Silva wrote:
>
> >
> > > + 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;
> >
> > msg->data used twice and a "sizeof()" earlier... might be nicer to have
> > an explicit pointer?
>
> Those are two different pointers:
>
> *(struct ec_params_hang_detect *)msg->data = arg->req;
> arg->resp = *(struct ec_response_hang_detect *)msg->data;
Argh. I did it again. I can't see "params" vs "response". q_q
Sorry for the noise!
Reviewed-by: Kees Cook <kees@kernel.org>
--
Kees Cook
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH v2][next] watchdog: cros-ec: Avoid -Wflex-array-member-not-at-end warning
2025-03-27 17:12 [PATCH v2][next] watchdog: cros-ec: Avoid -Wflex-array-member-not-at-end warning Gustavo A. R. Silva
2025-03-28 4:41 ` Guenter Roeck
2025-04-07 19:13 ` Kees Cook
@ 2025-04-16 0:24 ` Gustavo A. R. Silva
2 siblings, 0 replies; 6+ messages in thread
From: Gustavo A. R. Silva @ 2025-04-16 0:24 UTC (permalink / raw)
To: Gustavo A. R. Silva, Lukasz Majczak, Wim Van Sebroeck,
Guenter Roeck, Benson Leung, Tzung-Bi Shih
Cc: chrome-platform, linux-watchdog, linux-kernel, linux-hardening,
Kees Cook
Hi all,
Friendly ping: who can take this patch, please? 🙂
Thanks!
-Gustavo
On 27/03/25 11:12, 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.
>
> 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]
>
> Reviewed-by: Tzung-Bi Shih <tzungbi@kernel.org>
> Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
> ---
> Changes v2:
> - Fix truncated line in changelog text. (Tzung-Bi)
> - Update variable name: s/buf/msg (Tzung-Bi)
> - Cast to structs instead of union. (Tzung-Bi)
> - Add RB tag.
>
> v1:
> - Link: https://lore.kernel.org/linux-hardening/Z-SBITmMfwjocYwL@kspp/
>
> drivers/watchdog/cros_ec_wdt.c | 30 +++++++++++++-----------------
> 1 file changed, 13 insertions(+), 17 deletions(-)
>
> diff --git a/drivers/watchdog/cros_ec_wdt.c b/drivers/watchdog/cros_ec_wdt.c
> index 716c23f4388c..9ffe7f505645 100644
> --- 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;
> }
^ permalink raw reply [flat|nested] 6+ messages in thread