Re: [PATCH v2] drm/i915/tc: Fix -Wformat-truncation in intel_tc_port_init

[Andrzej Hajda <andrzej.hajda@xxxxxxxxx>]

On 25.10.2023 19:08, Nirmoy Das wrote:
> Fix below compiler warning:
>
> intel_tc.c:1879:11: error: ‘%d’ directive output may be truncated
> writing between 1 and 11 bytes into a region of size 3
> [-Werror=format-truncation=]
> "%c/TC#%d", port_name(port), tc_port + 1);
>             ^~
> intel_tc.c:1878:2: note: ‘snprintf’ output between 7 and 17 bytes
> into a destination of size 8
>    snprintf(tc->port_name, sizeof(tc->port_name),
>    ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>      "%c/TC#%d", port_name(port), tc_port + 1);
>      ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>
> v2: use kasprintf(Imre)
>
> Fixes: 3eafcddf766b ("drm/i915/tc: Move TC port fields to a new intel_tc_port struct")
> Cc: Mika Kahola <mika.kahola@xxxxxxxxx>
> Cc: Imre Deak <imre.deak@xxxxxxxxx>
> Cc: Jani Nikula <jani.nikula@xxxxxxxxx>
> Signed-off-by: Nirmoy Das <nirmoy.das@xxxxxxxxx>

Reviewed-by: Andrzej Hajda <andrzej.hajda@xxxxxxxxx>

Regards
Andrzej

> ---
>   drivers/gpu/drm/i915/display/intel_tc.c | 9 ++++++---
>   1 file changed, 6 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/display/intel_tc.c b/drivers/gpu/drm/i915/display/intel_tc.c
> index 37b0f8529b4f..0fa54450d51b 100644
> --- a/drivers/gpu/drm/i915/display/intel_tc.c
> +++ b/drivers/gpu/drm/i915/display/intel_tc.c
> @@ -58,7 +58,7 @@ struct intel_tc_port {
>   	struct delayed_work link_reset_work;
>   	int link_refcount;
>   	bool legacy_port:1;
> -	char port_name[8];
> +	char *port_name;
>   	enum tc_port_mode mode;
>   	enum tc_port_mode init_mode;
>   	enum phy_fia phy_fia;
> @@ -1875,8 +1875,10 @@ int intel_tc_port_init(struct intel_digital_port *dig_port, bool is_legacy)
>   	else
>   		tc->phy_ops = &icl_tc_phy_ops;
>   
> -	snprintf(tc->port_name, sizeof(tc->port_name),
> -		 "%c/TC#%d", port_name(port), tc_port + 1);
> +	tc->port_name = kasprintf(GFP_KERNEL, "%c/TC#%d", port_name(port),
> +				  tc_port + 1);
> +	if (!tc->port_name)
> +		return -ENOMEM;
>   
>   	mutex_init(&tc->lock);
>   	/* TODO: Combine the two works */
> @@ -1897,6 +1899,7 @@ void intel_tc_port_cleanup(struct intel_digital_port *dig_port)
>   {
>   	intel_tc_port_suspend(dig_port);
>   
> +	kfree(dig_port->tc->port_name);
>   	kfree(dig_port->tc);
>   	dig_port->tc = NULL;
>   }