Re: [PATCH] drm/xe: Fix uninitialized return value from xe_validation_guard()

[Maarten Lankhorst <maarten.lankhorst@intel.com>]

Glad to see it fixed!

Reviewed-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>

Den 2025-10-27 kl. 14:12, skrev Thomas Hellström:
> The parameter _ret is assigned in xe_validation_guard() not
> realizing we're assigning a parameter in a function rather than
> in a macro. That means it's value is not propagated to the caller.
>
> Fix this by making the _ret parameter a pointer.
>
> Fixes: c460bc2311df ("drm/xe: Introduce an xe_validation wrapper around drm_exec")
> Link: https://gitlab.freedesktop.org/drm/xe/kernel/-/issues/6220
> Cc: Maarten Lankhorst <maarten.lankhorst@intel.com>
> Cc: Matthew Brost <matthew.brost@intel.com>
> Cc: intel-xe@lists.freedesktop.org
> Signed-off-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>
> ---
>  drivers/gpu/drm/xe/xe_validation.h | 8 ++++----
>  1 file changed, 4 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/gpu/drm/xe/xe_validation.h b/drivers/gpu/drm/xe/xe_validation.h
> index fec331d791e7..b2d09c596714 100644
> --- a/drivers/gpu/drm/xe/xe_validation.h
> +++ b/drivers/gpu/drm/xe/xe_validation.h
> @@ -166,10 +166,10 @@ xe_validation_device_init(struct xe_validation_device *val)
>   */
>  DEFINE_CLASS(xe_validation, struct xe_validation_ctx *,
>  	     if (_T) xe_validation_ctx_fini(_T);,
> -	     ({_ret = xe_validation_ctx_init(_ctx, _val, _exec, _flags);
> -	       _ret ? NULL : _ctx; }),
> +	     ({*_ret = xe_validation_ctx_init(_ctx, _val, _exec, _flags);
> +	       *_ret ? NULL : _ctx; }),
>  	     struct xe_validation_ctx *_ctx, struct xe_validation_device *_val,
> -	     struct drm_exec *_exec, const struct xe_val_flags _flags, int _ret);
> +	     struct drm_exec *_exec, const struct xe_val_flags _flags, int *_ret);
>  static inline void *class_xe_validation_lock_ptr(class_xe_validation_t *_T)
>  {return *_T; }
>  #define class_xe_validation_is_conditional true
> @@ -186,7 +186,7 @@ static inline void *class_xe_validation_lock_ptr(class_xe_validation_t *_T)
>   * exhaustive eviction.
>   */
>  #define xe_validation_guard(_ctx, _val, _exec, _flags, _ret)		\
> -	scoped_guard(xe_validation, _ctx, _val, _exec, _flags, _ret) \
> +	scoped_guard(xe_validation, _ctx, _val, _exec, _flags, &_ret) \
>  	drm_exec_until_all_locked(_exec)
>  
>  #endif