Re: [PATCH] drm/i915/gt: Remove const from struct i915_wa list allocation

[Jani Nikula <jani.nikula@linux.intel.com>]

On Fri, 25 Apr 2025, Kees Cook <kees@kernel.org> wrote:
> In preparation for making the kmalloc family of allocators type aware,
> we need to make sure that the returned type from the allocation matches
> the type of the variable being assigned. (Before, the allocator would
> always return "void *", which can be implicitly cast to any pointer type.)
>
> The assigned type is "struct i915_wa *". The returned type, while
> technically matching, will be const qualified. As there is no general
> way to remove const qualifiers, adjust the allocation type to match
> the assignment.
>
> Signed-off-by: Kees Cook <kees@kernel.org>

Acked-by: Jani Nikula <jani.nikula@intel.com>

for merging via whichever tree you find best; please let us know if you
want us to pick this up via drm-intel.

> ---
> Cc: Jani Nikula <jani.nikula@linux.intel.com>
> Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
> Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
> Cc: Tvrtko Ursulin <tursulin@ursulin.net>
> Cc: David Airlie <airlied@gmail.com>
> Cc: Simona Vetter <simona@ffwll.ch>
> Cc: Matt Roper <matthew.d.roper@intel.com>
> Cc: Gustavo Sousa <gustavo.sousa@intel.com>
> Cc: Andi Shyti <andi.shyti@linux.intel.com>
> Cc: Lucas De Marchi <lucas.demarchi@intel.com>
> Cc: <intel-gfx@lists.freedesktop.org>
> Cc: <dri-devel@lists.freedesktop.org>
> ---
>  drivers/gpu/drm/i915/gt/intel_workarounds.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/i915/gt/intel_workarounds.c b/drivers/gpu/drm/i915/gt/intel_workarounds.c
> index 116683ebe074..b37e400f74e5 100644
> --- a/drivers/gpu/drm/i915/gt/intel_workarounds.c
> +++ b/drivers/gpu/drm/i915/gt/intel_workarounds.c
> @@ -156,7 +156,7 @@ static void _wa_add(struct i915_wa_list *wal, const struct i915_wa *wa)
>  	if (IS_ALIGNED(wal->count, grow)) { /* Either uninitialized or full. */
>  		struct i915_wa *list;
>  
> -		list = kmalloc_array(ALIGN(wal->count + 1, grow), sizeof(*wa),
> +		list = kmalloc_array(ALIGN(wal->count + 1, grow), sizeof(*list),
>  				     GFP_KERNEL);
>  		if (!list) {
>  			drm_err(&i915->drm, "No space for workaround init!\n");

-- 
Jani Nikula, Intel