[PATCH 3/3] drm/amd/amdgpu: Fix NULL pointer OOPS during S3

[Christian König]

NAK as well. mem->mm_node can't be NULL on a correctly allocated BO.

You are running into a BO corruption here and trying to work around by 
mitigating the effect and not fixing the root problem.

Regards,
Christian.

Am 06.06.2018 um 11:25 schrieb Pratik Vishwakarma:
> Fixes NULL pointer dereference in amdgpu_ttm_copy_mem_to_mem
>
> BUG: unable to handle kernel NULL pointer dereference at 0000000000000010
> IP: amdgpu_ttm_copy_mem_to_mem+0x85/0x40c
> Workqueue: events_unbound async_run_entry_fn
> Call Trace:
> ? _raw_spin_unlock+0xe/0x20
> ? ttm_check_swapping+0x4e/0x72
> ? ttm_mem_global_reserve.constprop.4+0xb1/0xc0
> amdgpu_move_blit+0x80/0xe2
> amdgpu_bo_move+0x114/0x155
> ttm_bo_handle_move_mem+0x1f7/0x34a
> ? ttm_bo_mem_space+0x162/0x38e
> ? dev_vprintk_emit+0x10a/0x1f2
> ttm_bo_evict+0x13e/0x2e9
> ? do_wait_for_common+0x151/0x187
> ttm_mem_evict_first+0x136/0x181
> ttm_bo_force_list_clean+0x78/0x10f
> amdgpu_device_suspend+0x167/0x210
> pci_pm_suspend+0x12a/0x1a5
> ? pci_dev_driver+0x36/0x36
> dpm_run_callback+0x59/0xbf
> __device_suspend+0x215/0x33f
> async_suspend+0x1f/0x5c
> async_run_entry_fn+0x3d/0xd2
> process_one_work+0x1b0/0x314
> worker_thread+0x1cb/0x2c1
> ? create_worker+0x1da/0x1da
> kthread+0x156/0x15e
> ? kthread_flush_work+0xea/0xea
> ret_from_fork+0x22/0x40
>
> Signed-off-by: Pratik Vishwakarma <Pratik.Vishwakarma at amd.com>
> ---
>   drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c | 4 ++++
>   1 file changed, 4 insertions(+)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
> index 57d4da6..f9de429 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
> @@ -414,12 +414,16 @@ int amdgpu_ttm_copy_mem_to_mem(struct amdgpu_device *adev,
>   		return -EINVAL;
>   	}
>   
> +	if (!src->mem->mm_node)
> +		return -EINVAL;
>   	src_mm = amdgpu_find_mm_node(src->mem, &src->offset);
>   	src_node_start = amdgpu_mm_node_addr(src->bo, src_mm, src->mem) +
>   					     src->offset;
>   	src_node_size = (src_mm->size << PAGE_SHIFT) - src->offset;
>   	src_page_offset = src_node_start & (PAGE_SIZE - 1);
>   
> +	if (!dst->mem->mm_node)
> +		return -EINVAL;
>   	dst_mm = amdgpu_find_mm_node(dst->mem, &dst->offset);
>   	dst_node_start = amdgpu_mm_node_addr(dst->bo, dst_mm, dst->mem) +
>   					     dst->offset;