Re: [PATCH] platform/chrome: cros_ec_proto: remove big stub objects from stack

[Guenter Roeck <linux@roeck-us.net>]

On Tue, Jan 17, 2023 at 04:02:54PM +0800, Tzung-Bi Shih wrote:
> sizeof(struct device) = 680
> sizeof(struct cros_ec_dev) = 720
> 
> They tend to exceed the stack frame size limit in some specific
> environment which results in the following compilation error:
> 
> >> drivers/platform/chrome/cros_ec_proto_test.c:2530:13: error: stack
> frame size (2128) exceeds limit (2048) in
> 'cros_ec_proto_test_get_sensor_count_legacy'
> 
> Remove the big stub objects from stack.
> 
> This is:
> $ sed -i 's/struct cros_ec_dev /static struct cros_ec_dev /' \
>     drivers/platform/chrome/cros_ec_proto_test.c
> 
> Reported-by: kernel test robot <lkp@intel.com>
> Signed-off-by: Tzung-Bi Shih <tzungbi@kernel.org>

Reviewed-by: Guenter Roeck <linux@roeck-us.net>

> ---
>  drivers/platform/chrome/cros_ec_proto_test.c | 10 +++++-----
>  1 file changed, 5 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/platform/chrome/cros_ec_proto_test.c b/drivers/platform/chrome/cros_ec_proto_test.c
> index 08c58d031593..5b9748e0463b 100644
> --- a/drivers/platform/chrome/cros_ec_proto_test.c
> +++ b/drivers/platform/chrome/cros_ec_proto_test.c
> @@ -2371,7 +2371,7 @@ static void cros_ec_proto_test_get_host_event_normal(struct kunit *test)
>  static void cros_ec_proto_test_check_features_cached(struct kunit *test)
>  {
>  	int ret, i;
> -	struct cros_ec_dev ec;
> +	static struct cros_ec_dev ec;
>  
>  	ec.features.flags[0] = EC_FEATURE_MASK_0(EC_FEATURE_FINGERPRINT);
>  	ec.features.flags[1] = EC_FEATURE_MASK_0(EC_FEATURE_SCP);
> @@ -2396,7 +2396,7 @@ static void cros_ec_proto_test_check_features_not_cached(struct kunit *test)
>  	struct cros_ec_device *ec_dev = &priv->ec_dev;
>  	struct ec_xfer_mock *mock;
>  	int ret, i;
> -	struct cros_ec_dev ec;
> +	static struct cros_ec_dev ec;
>  
>  	ec_dev->max_request = 0xff;
>  	ec_dev->max_response = 0xee;
> @@ -2449,7 +2449,7 @@ static void cros_ec_proto_test_get_sensor_count_normal(struct kunit *test)
>  	struct cros_ec_device *ec_dev = &priv->ec_dev;
>  	struct ec_xfer_mock *mock;
>  	int ret;
> -	struct cros_ec_dev ec;
> +	static struct cros_ec_dev ec;
>  
>  	ec_dev->max_request = 0xff;
>  	ec_dev->max_response = 0xee;
> @@ -2494,7 +2494,7 @@ static void cros_ec_proto_test_get_sensor_count_xfer_error(struct kunit *test)
>  	struct cros_ec_device *ec_dev = &priv->ec_dev;
>  	struct ec_xfer_mock *mock;
>  	int ret;
> -	struct cros_ec_dev ec;
> +	static struct cros_ec_dev ec;
>  
>  	ec_dev->max_request = 0xff;
>  	ec_dev->max_response = 0xee;
> @@ -2534,7 +2534,7 @@ static void cros_ec_proto_test_get_sensor_count_legacy(struct kunit *test)
>  	struct cros_ec_device *ec_dev = &priv->ec_dev;
>  	struct ec_xfer_mock *mock;
>  	int ret, i;
> -	struct cros_ec_dev ec;
> +	static struct cros_ec_dev ec;
>  	struct {
>  		u8 readmem_data;
>  		int expected_result;