Re: [PATCH v2 2/9] drm/xe/hw_error: Initialize hw_error_work per tile

["Mallesh, Koujalagi" <mallesh.koujalagi@intel.com>]

On 26-10-2026 11:35 am, Riana Tauro wrote:
> From: Raag Jadav <raag.jadav@intel.com>
>
> Since hw_error_work is now being reused generically, initialize it per tile
> so that we don't hit uninitialized work for non-root tile. While at it,
> disable hw_error_work on fini to prevent UAF during unwind.
>
> Signed-off-by: Raag Jadav <raag.jadav@intel.com>
> Reviewed-by: Riana Tauro <riana.tauro@intel.com>
> ---
>   drivers/gpu/drm/xe/xe_hw_error.c | 24 ++++++++++++++++++++++--
>   drivers/gpu/drm/xe/xe_hw_error.h |  1 +
>   2 files changed, 23 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/gpu/drm/xe/xe_hw_error.c b/drivers/gpu/drm/xe/xe_hw_error.c
> index 41ddd997478b..f7799c3c08aa 100644
> --- a/drivers/gpu/drm/xe/xe_hw_error.c
> +++ b/drivers/gpu/drm/xe/xe_hw_error.c
> @@ -537,6 +537,23 @@ static void process_hw_errors(struct xe_device *xe)
>   	}
>   }
>   
> +/**
> + * xe_hw_error_work_disable - Disable hw error work
> + * @arg: xe device instance
> + *
> + * This function disables the delayed work for hardware error handling
> + * for all tiles.
> + */
> +void xe_hw_error_work_disable(void *arg)
> +{
> +	struct xe_device *xe = arg;
> +	struct xe_tile *tile;
> +	u8 id;
> +
> +	for_each_tile(tile, xe, id)
> +		disable_delayed_work_sync(&tile->hw_error_work);
> +}
> +

hmm, we are disabling hw_error_work.

IMO, if we see non-fatal error fires on the IRQ path (since it's 
asynchronous), since the work is still disabled,

it would not be processed further.


Thanks,

-/Mallesh

>   /**
>    * xe_hw_error_init - Initialize hw errors
>    * @xe: xe device instance
> @@ -546,12 +563,15 @@ static void process_hw_errors(struct xe_device *xe)
>    */
>   void xe_hw_error_init(struct xe_device *xe)
>   {
> -	struct xe_tile *tile = xe_device_get_root_tile(xe);
> +	struct xe_tile *tile;
> +	u8 id;
>   
>   	if (!IS_DGFX(xe) || IS_SRIOV_VF(xe))
>   		return;
>   
> -	INIT_DELAYED_WORK(&tile->hw_error_work, hw_error_work);
> +	for_each_tile(tile, xe, id)
> +		INIT_DELAYED_WORK(&tile->hw_error_work, hw_error_work);
>   
>   	process_hw_errors(xe);
> +	devm_add_action_or_reset(xe->drm.dev, xe_hw_error_work_disable, xe);
>   }
> diff --git a/drivers/gpu/drm/xe/xe_hw_error.h b/drivers/gpu/drm/xe/xe_hw_error.h
> index 5e3a11424108..c2c0bfa6d9f9 100644
> --- a/drivers/gpu/drm/xe/xe_hw_error.h
> +++ b/drivers/gpu/drm/xe/xe_hw_error.h
> @@ -12,4 +12,5 @@ struct xe_device;
>   
>   void xe_hw_error_irq_handler(struct xe_tile *tile, const u32 master_ctl);
>   void xe_hw_error_init(struct xe_device *xe);
> +void xe_hw_error_work_disable(void *arg);
>   #endif