From: jsg <jsg@openbsd.org>
Date: Wed, 20 Mar 2024 03:02:24 +0000 (+0000)
Subject: handle ttm_sg_tt_init() not being called before ttm_tt_fini()
X-Git-Url: http://artulab.com/gitweb/?a=commitdiff_plain;h=fb366a915a43e2eb92cc455bbd665f66e4c0fc05;p=openbsd

handle ttm_sg_tt_init() not being called before ttm_tt_fini()

Check that dmamap and segs are non-NULL as not all drivers call
ttm_sg_tt_init().
---

diff --git a/sys/dev/pci/drm/ttm/ttm_tt.c b/sys/dev/pci/drm/ttm/ttm_tt.c
index 38625196072..21d1d9cfe70 100644
--- a/sys/dev/pci/drm/ttm/ttm_tt.c
+++ b/sys/dev/pci/drm/ttm/ttm_tt.c
@@ -151,6 +151,9 @@ static void ttm_tt_init_fields(struct ttm_tt *ttm,
 	ttm->swap_storage = NULL;
 	ttm->sg = bo->sg;
 	ttm->caching = caching;
+	ttm->dmat = bo->bdev->dmat;
+	ttm->map = NULL;
+	ttm->segs = NULL;
 }
 
 int ttm_tt_init(struct ttm_tt *ttm, struct ttm_buffer_object *bo,
@@ -184,9 +187,11 @@ void ttm_tt_fini(struct ttm_tt *ttm)
 	ttm->dma_address = NULL;
 	ttm->orders = NULL;
 
-	bus_dmamap_destroy(ttm->dmat, ttm->map);
-	km_free(ttm->segs, round_page(ttm->num_pages *
-	    sizeof(bus_dma_segment_t)), &kv_any, &kp_zero);
+	if (ttm->map)
+		bus_dmamap_destroy(ttm->dmat, ttm->map);
+	if (ttm->segs)
+		km_free(ttm->segs, round_page(ttm->num_pages *
+		    sizeof(bus_dma_segment_t)), &kv_any, &kp_zero);
 }
 EXPORT_SYMBOL(ttm_tt_fini);
 
@@ -210,8 +215,6 @@ int ttm_sg_tt_init(struct ttm_tt *ttm, struct ttm_buffer_object *bo,
 	ttm->segs = km_alloc(round_page(ttm->num_pages *
 	    sizeof(bus_dma_segment_t)), &kv_any, &kp_zero, &kd_waitok);
 
-	ttm->dmat = bo->bdev->dmat;
-
 	if (bo->bdev->pool.use_dma32 == false)
 		flags |= BUS_DMA_64BIT;
 	if (bus_dmamap_create(ttm->dmat, ttm->num_pages << PAGE_SHIFT,