[PATCH i-g-t v4 16/41] lib/vkms: Test connector invalid values

[Kamil Konieczny]

Hi José,
On 2025-08-07 at 09:45:25 +0200, José Expósito wrote:
> For a VKMS connector, it is only possible to set invalid values in the
> connector status.
> 
> Test that setting wrong values fails and that the connector is not
> accidentally changed.
> 
> Signed-off-by: José Expósito <jose.exposito89 at gmail.com>
> ---
>  lib/igt_vkms.c             | 24 ++++++++++++++++++
>  lib/igt_vkms.h             |  2 ++
>  tests/vkms/vkms_configfs.c | 50 ++++++++++++++++++++++++++++++++++++++
>  3 files changed, 76 insertions(+)
> 
> diff --git a/lib/igt_vkms.c b/lib/igt_vkms.c
> index 5d9e13ed7..a86d5e05d 100644
> --- a/lib/igt_vkms.c
> +++ b/lib/igt_vkms.c
> @@ -613,3 +613,27 @@ int igt_vkms_connector_get_status(igt_vkms_t *dev, const char *name)
>  
>  	return read_int(path);
>  }
> +
> +/**
> + * igt_vkms_connector_set_status:
> + * @dev: Device the connector belongs to
> + * @name: Connector name
> + * @type: DRM_MODE_CONNECTED, DRM_MODE_DISCONNECTED or
> + * DRM_MODE_UNKNOWNCONNECTION
> + *
> + * Set a new status for the connector
> + */
> +void igt_vkms_connector_set_status(igt_vkms_t *dev, const char *name,
> +				   int status)
> +{
> +	char path[PATH_MAX];
> +
> +	if (status != DRM_MODE_CONNECTED &&
> +	    status != DRM_MODE_DISCONNECTED &&
> +	    status != DRM_MODE_UNKNOWNCONNECTION)
> +		igt_assert(!"Cannot be reached: Unknown connector status");
> +
> +	igt_vkms_get_connector_status_path(dev, name, path, sizeof(path));
> +
> +	write_int(path, status);
> +}
> diff --git a/lib/igt_vkms.h b/lib/igt_vkms.h
> index 13d7ed094..596990547 100644
> --- a/lib/igt_vkms.h
> +++ b/lib/igt_vkms.h
> @@ -58,5 +58,7 @@ void igt_vkms_device_add_encoder(igt_vkms_t *dev, const char *name);
>  
>  void igt_vkms_device_add_connector(igt_vkms_t *dev, const char *name);
>  int igt_vkms_connector_get_status(igt_vkms_t *dev, const char *name);
> +void igt_vkms_connector_set_status(igt_vkms_t *dev, const char *name,
> +				   int status);
>  
>  #endif /* __IGT_VKMS_H__ */
> diff --git a/tests/vkms/vkms_configfs.c b/tests/vkms/vkms_configfs.c
> index b3fafc069..987491373 100644
> --- a/tests/vkms/vkms_configfs.c
> +++ b/tests/vkms/vkms_configfs.c
> @@ -485,6 +485,55 @@ static void test_connector_default_values(void)
>  	igt_vkms_device_destroy(dev);
>  }
>  
> +/**
> + * SUBTEST: connector-wrong-values
> + * Description: Check that setting unexpected values doesn't work.
> + */
> +
> +static void test_connector_wrong_values(void)
> +{
> +	struct invalid_value invalid_status_values[] = {
> +		{ "", 0 },

Write of zero bytes will not reach your driver, see man 2 write.
With this line removed

Acked-by: Kamil Konieczny <kamil.konieczny at linux.intel.com>

PS. Louis - gentle ping on review this last patch.

> +		{ "\0", 1 },

btw imho 
		{ "", 1 },
is also valid.

> +		{ "-1", 2 },
> +		{ "0", 1 },
> +		{ "4", 1 },
> +		{ "connected", 10 },
> +	};
> +	igt_vkms_t *dev;
> +	char path[PATH_MAX];
> +	int fd;
> +	int ret;
> +
> +	/* Create a device with a disconnected connector */
> +	dev = igt_vkms_device_create(__func__);
> +	igt_assert(dev);
> +
> +	igt_vkms_device_add_connector(dev, "connector0");
> +	igt_vkms_connector_set_status(dev, "connector0", DRM_MODE_DISCONNECTED);
> +	igt_assert_eq(igt_vkms_connector_get_status(dev, "connector0"),
> +		      DRM_MODE_DISCONNECTED);
> +	igt_vkms_get_connector_status_path(dev, "connector0", path, sizeof(path));
> +
> +	/* Test invalid values for "status" */
> +	for (int i = 0; i < ARRAY_SIZE(invalid_status_values); i++) {
> +		struct invalid_value v = invalid_status_values[i];
> +
> +		fd = open(path, O_WRONLY);
> +		igt_assert_f(fd >= 0, "Error opening '%s'\n", path);
> +
> +		ret = write(fd, v.value, v.size);
> +		igt_assert(ret <= 0);

With zero-byte write removed this should be 'ret < 0'?

Regards,
Kamil

> +
> +		close(fd);
> +	}
> +
> +	igt_assert_eq(igt_vkms_connector_get_status(dev, "connector0"),
> +		      DRM_MODE_DISCONNECTED);
> +
> +	igt_vkms_device_destroy(dev);
> +}
> +
>  igt_main
>  {
>  	struct {
> @@ -505,6 +554,7 @@ igt_main
>  		{ "encoder-default-files", test_encoder_default_files },
>  		{ "connector-default-files", test_connector_default_files },
>  		{ "connector-default-values", test_connector_default_values },
> +		{ "connector-wrong-values", test_connector_wrong_values },
>  	};
>  
>  	igt_fixture {
> -- 
> 2.50.1
>