[PATCH] drm/xe/vm: bugfix in xe_vm_create_ioctl

[Matthew Brost]

On Thu, Jan 18, 2024 at 07:31:55PM +0200, Moti Haimovski wrote:
> Fix xe_vm_create_ioctl routine not freeing the vm-id allocated to it
> when the function fails.
> 
> Relates to: FSW-1360 xe_vm_create_ioctl does not free vm id on error.
> 

This needs the following tag:
Fixes: dd08ebf6c352 ("drm/xe: Introduce a new DRM driver for Intel GPUs")

> Signed-off-by: Moti Haimovski <mhaimovski at habana.ai>

With that tag added:
Reviewed-by: Matthew Brost <matthew.brost at intel.com>

> ---
>  drivers/gpu/drm/xe/xe_vm.c | 22 +++++++++++++---------
>  1 file changed, 13 insertions(+), 9 deletions(-)
> 
> diff --git a/drivers/gpu/drm/xe/xe_vm.c b/drivers/gpu/drm/xe/xe_vm.c
> index a7e7a0b24099..8dbe13676a2f 100644
> --- a/drivers/gpu/drm/xe/xe_vm.c
> +++ b/drivers/gpu/drm/xe/xe_vm.c
> @@ -1855,10 +1855,8 @@ int xe_vm_create_ioctl(struct drm_device *dev, void *data,
>  	mutex_lock(&xef->vm.lock);
>  	err = xa_alloc(&xef->vm.xa, &id, vm, xa_limit_32b, GFP_KERNEL);
>  	mutex_unlock(&xef->vm.lock);
> -	if (err) {
> -		xe_vm_close_and_put(vm);
> -		return err;
> -	}
> +	if (err)
> +		goto err_exit;
>  
>  	if (xe->info.has_asid) {
>  		mutex_lock(&xe->usm.lock);
> @@ -1866,11 +1864,9 @@ int xe_vm_create_ioctl(struct drm_device *dev, void *data,
>  				      XA_LIMIT(1, XE_MAX_ASID - 1),
>  				      &xe->usm.next_asid, GFP_KERNEL);
>  		mutex_unlock(&xe->usm.lock);
> -		if (err < 0) {
> -			xe_vm_close_and_put(vm);
> -			return err;
> -		}
> -		err = 0;
> +		if (err < 0)
> +			goto free_id;
> +
>  		vm->usm.asid = asid;
>  	}
>  
> @@ -1888,6 +1884,14 @@ int xe_vm_create_ioctl(struct drm_device *dev, void *data,
>  #endif
>  
>  	return 0;
> +
> +free_id:
> +	mutex_lock(&xef->vm.lock);
> +	xa_erase(&xef->vm.xa, id);
> +	mutex_unlock(&xef->vm.lock);
> +err_exit:
> +	xe_vm_close_and_put(vm);
> +	return err;
>  }
>  
>  int xe_vm_destroy_ioctl(struct drm_device *dev, void *data,
> -- 
> 2.34.1
>