[Intel-gfx] [PATCH v3] drm/i915/tc: Fix -Wformat-truncation in intel_tc_port_init

[Kahola, Mika]

> -----Original Message-----
> From: Das, Nirmoy <nirmoy.das at intel.com>
> Sent: Thursday, October 26, 2023 3:57 PM
> To: intel-gfx at lists.freedesktop.org
> Cc: Das, Nirmoy <nirmoy.das at intel.com>; Kahola, Mika <mika.kahola at intel.com>; Deak, Imre <imre.deak at intel.com>; Nikula,
> Jani <jani.nikula at intel.com>; Hajda, Andrzej <andrzej.hajda at intel.com>
> Subject: [PATCH v3] drm/i915/tc: Fix -Wformat-truncation in intel_tc_port_init
> 
> 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)
> v3: use const for port_name, and fix tc mem leak(Imre)
> 
> Fixes: 3eafcddf766b ("drm/i915/tc: Move TC port fields to a new intel_tc_port struct")
> Cc: Mika Kahola <mika.kahola at intel.com>
> Cc: Imre Deak <imre.deak at intel.com>
> Cc: Jani Nikula <jani.nikula at intel.com>
> Signed-off-by: Nirmoy Das <nirmoy.das at intel.com>
> Reviewed-by: Andrzej Hajda <andrzej.hajda at intel.com>
> Reviewed-by: Imre Deak <imre.deak at intel.com>

Reviewed-by: Mika Kahola <mika.kahola at intel.com>

> ---
>  drivers/gpu/drm/i915/display/intel_tc.c | 11 ++++++++---
>  1 file changed, 8 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..f64d348a969e 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];
> +	const char *port_name;
>  	enum tc_port_mode mode;
>  	enum tc_port_mode init_mode;
>  	enum phy_fia phy_fia;
> @@ -1875,8 +1875,12 @@ 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) {
> +		kfree(tc);
> +		return -ENOMEM;
> +	}
> 
>  	mutex_init(&tc->lock);
>  	/* TODO: Combine the two works */
> @@ -1897,6 +1901,7 @@ 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;
>  }
> --
> 2.42.0