[PATCH 67/95] drm/amdgpu: fix dma_buf leak in UALink exporter cleanup

From: Mukul Joshi <[email protected]>

At export time the driver code always builds a dma_buf for the BO
which is then shared for local imports.
During cleanup, if there are no importers, which is true for local imports,
we never free the dma_buf thus causing the memory leak.

Fix by dropping the dma_buf reference in the no-importers branch as well.

Signed-off-by: Mukul Joshi <[email protected]>
Reviewed-by: Harish Kasiviswanathan <[email protected]>
Signed-off-by: Alex Deucher <[email protected]>
---
 drivers/gpu/drm/amd/amdgpu/amdgpu_ualink.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ualink.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_ualink.c
index 66ae6a0f1c53b..dd45c2e20be0a 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ualink.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ualink.c
@@ -2220,6 +2220,12 @@ static void amdgpu_ualink_exp_cleanup_worker(struct work_struct *work)
 	/* If there are no importers for this BO/handle */
 	if (bitmap_empty(exp_xa_node->importers_bitmap,
 			 AMDGPU_UALINK_ACCEL_MAX)) {
+		/* Release the dma_buf created at export time (used for the
+		 * local-import shortcut). The has-importers path below drops
+		 * it too; this branch must not skip it or the dma_buf and the
+		 * BO it pins are leaked.
+		 */
+		dma_buf_put(exp_xa_node->dmabuf);
 		/* Drop the BO reference so it can be freed. */
 		amdgpu_bo_unref(&bo);
 		exp_xa_node->bo = NULL;
-- 
2.55.0