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

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.

Cc: stable@vger.kernel.org
Signed-off-by: Tom St Denis <tom.stdenis@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

1 files changed, 3 insertions, 0 deletions

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
index fcf617c237ef..8526a0222268 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;