[PATCH 6.6 181/396] drm/amdgpu: amdgpu_ttm_gart_bind set gtt bound flag

Greg Kroah-Hartman
2024-04-01T16:46:13Z

From: Philip Yang <Philip.Yang@amd.com>

[ Upstream commit 6c6064cbe58b43533e3451ad6a8ba9736c109ac3 ]

Otherwise after the GTT bo is released, the GTT and gart space is freed
but amdgpu_ttm_backend_unbind will not clear the gart page table entry
and leave valid mapping entry pointing to the stale system page. Then
if GPU access the gart address mistakely, it will read undefined value
instead page fault, harder to debug and reproduce the real issue.

Cc: stable@vger.kernel.org
Signed-off-by: Philip Yang <Philip.Yang@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c | 1 +
1 file changed, 1 insertion(+)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
index f573909332c01..928107d0bfea4 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
@@ -869,6 +869,7 @@ static void amdgpu_ttm_gart_bind(struct amdgpu_device *adev,
amdgpu_gart_bind(adev, gtt->offset, ttm->num_pages,
gtt->ttm.dma_address, flags);
}
+ gtt->bound = true;
}

/*
--
2.43.0