add new system file

hc

2024-02-20 102a0743326a03cd1a1202ceda21e175b7d3575c

 kernel/drivers/gpu/drm/drm_gem_shmem_helper.c
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@@ -614,11 +614,20 @@
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 	int ret;
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 	if (obj->import_attach) {
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-		/* Drop the reference drm_gem_mmap_obj() acquired.*/
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-		drm_gem_object_put(obj);
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+		/* Reset both vm_ops and vm_private_data, so we don't end up with
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+		 * vm_ops pointing to our implementation if the dma-buf backend
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+		 * doesn't set those fields.
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+		 */
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 		vma->vm_private_data = NULL;
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+		vma->vm_ops = NULL;
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-		return dma_buf_mmap(obj->dma_buf, vma, 0);
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+		ret = dma_buf_mmap(obj->dma_buf, vma, 0);
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+
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+		/* Drop the reference drm_gem_mmap_obj() acquired.*/
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+		if (!ret)
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+			drm_gem_object_put(obj);
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+
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+		return ret;
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 	}
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 	shmem = to_drm_gem_shmem_obj(obj);