Fix various NIC drivers to properly cleanup static DMA resources.

In particular, don't check the value of the bus_dma map against NULL
to determine if either bus_dmamem_alloc() or bus_dmamap_load() succeeded.
Instead, assume that bus_dmamap_load() succeeeded (and thus that
bus_dmamap_unload() should be called) if the bus address for a resource
is non-zero, and assume that bus_dmamem_alloc() succeeded (and thus
that bus_dmamem_free() should be called) if the virtual address for a
resource is not NULL.

In many cases these bugs could result in leaks when a driver was detached.

Reviewed by:	yongari
MFC after:	2 weeks

1 files changed, 4 insertions, 4 deletions

diff --git a/sys/dev/sis/if_sis.c b/sys/dev/sis/if_sis.c
index 632b384..09e2242 100644
--- a/sys/dev/sis/if_sis.c
+++ b/sys/dev/sis/if_sis.c
@@ -1329,9 +1329,9 @@ sis_dma_free(struct sis_softc *sc)
 		bus_dma_tag_destroy(sc->sis_tx_tag);
 
 	/* Destroy RX ring. */
-	if (sc->sis_rx_list_map)
+	if (sc->sis_rx_paddr)
 		bus_dmamap_unload(sc->sis_rx_list_tag, sc->sis_rx_list_map);
-	if (sc->sis_rx_list_map && sc->sis_rx_list)
+	if (sc->sis_rx_list)
 		bus_dmamem_free(sc->sis_rx_list_tag, sc->sis_rx_list,
 		    sc->sis_rx_list_map);
 
@@ -1339,10 +1339,10 @@ sis_dma_free(struct sis_softc *sc)
 		bus_dma_tag_destroy(sc->sis_rx_list_tag);
 
 	/* Destroy TX ring. */
-	if (sc->sis_tx_list_map)
+	if (sc->sis_tx_paddr)
 		bus_dmamap_unload(sc->sis_tx_list_tag, sc->sis_tx_list_map);
 
-	if (sc->sis_tx_list_map && sc->sis_tx_list)
+	if (sc->sis_tx_list)
 		bus_dmamem_free(sc->sis_tx_list_tag, sc->sis_tx_list,
 		    sc->sis_tx_list_map);