[PATCH] drm/ttm: fix missing NULL check in ttm_device_swapout

[Christian König]

Am 14.07.22 um 23:58 schrieb Felix Kuehling:
> Backport of Christian's patch 81b0d0e4f811 to amd-staging-drm-next. This
> branch may be nearly obsolete, but this patch may still be worth
> applying as it can serve as a template for backports to some release
> branches. It fixes intermittent kernel oopses when memory is severely
> overcommitted.
>
> Signed-off-by: Felix Kuehling <Felix.Kuehling at amd.com>

I was hoping that Alex rebase would land before anybody notices this 
problem.

Anyway patch is Reviewed-by: Christian König <christian.koenig at amd.com>.

Regards,
Christian.

> ---
>   drivers/gpu/drm/ttm/ttm_device.c | 3 +++
>   1 file changed, 3 insertions(+)
>
> diff --git a/drivers/gpu/drm/ttm/ttm_device.c b/drivers/gpu/drm/ttm/ttm_device.c
> index be24bb6cefd0..165a6cbb45d5 100644
> --- a/drivers/gpu/drm/ttm/ttm_device.c
> +++ b/drivers/gpu/drm/ttm/ttm_device.c
> @@ -157,6 +157,9 @@ int ttm_device_swapout(struct ttm_device *bdev, struct ttm_operation_ctx *ctx,
>   			list_for_each_entry(bo, &man->lru[j], lru) {
>   				uint32_t num_pages = PFN_UP(bo->base.size);
>   
> +				if (!bo->resource)
> +					continue;
> +
>   				ret = ttm_bo_swapout(bo, ctx, gfp_flags);
>   				/* ttm_bo_swapout has dropped the lru_lock */
>   				if (!ret)