[PATCH] drm/amd/amdgpu: Return error if initiating read out of range on vram

[deathsimple@xxxxxxxxxxx (Christian König)]

Am 23.05.2017 um 17:59 schrieb Tom St Denis:
> If you initiate a read that is out of the VRAM address space return
> ENXIO instead of 0.
>
> Reads that begin below that point will read upto the VRAM limit as
> before.
>
> Signed-off-by: Tom St Denis <tom.stdenis at amd.com>

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

> ---
>   drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c | 3 +++
>   1 file changed, 3 insertions(+)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
> index 522f773203c8..399209495265 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
> @@ -1468,6 +1468,9 @@ static ssize_t amdgpu_ttm_vram_read(struct file *f, char __user *buf,
>   	if (size & 0x3 || *pos & 0x3)
>   		return -EINVAL;
>   
> +	if (*pos >= adev->mc.mc_vram_size)
> +		return -ENXIO;
> +
>   	while (size) {
>   		unsigned long flags;
>   		uint32_t value;