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, 20 insertions, 12 deletions

diff --git a/sys/arm/cavium/cns11xx/if_ece.c b/sys/arm/cavium/cns11xx/if_ece.c
index 657f6f3..0ba2d77 100644
--- a/sys/arm/cavium/cns11xx/if_ece.c
+++ b/sys/arm/cavium/cns11xx/if_ece.c
@@ -565,13 +565,15 @@ ece_free_desc_dma_tx(struct ece_softc *sc)
 		}
 	}
 
-	if (sc->dmamap_ring_tx) {
+	if (sc->ring_paddr_tx) {
 		bus_dmamap_unload(sc->dmatag_data_tx, sc->dmamap_ring_tx);
-		if (sc->desc_tx) {
-			bus_dmamem_free(sc->dmatag_data_tx,
-			    sc->desc_tx, sc->dmamap_ring_tx);
-		}
-		sc->dmamap_ring_tx = 0;
+		sc->ring_paddr_tx = 0;
+	}
+
+	if (sc->desc_tx) {
+		bus_dmamem_free(sc->dmatag_data_tx,
+		    sc->desc_tx, sc->dmamap_ring_tx);
+		sc->desc_tx = NULL;
 	}
 
 	if (sc->dmatag_data_tx) {
@@ -679,18 +681,24 @@ ece_free_desc_dma_rx(struct ece_softc *sc)
 	for (i = 0; i < ECE_MAX_RX_BUFFERS; i++) {
 		if (sc->rx_desc[i].buff) {
 			m_freem(sc->rx_desc[i].buff);
-			sc->rx_desc[i].buff= 0;
+			sc->rx_desc[i].buff = NULL;
 		}
 	}
 
-	if (sc->dmatag_data_rx) {
+	if (sc->ring_paddr_rx) {
 		bus_dmamap_unload(sc->dmatag_data_rx, sc->dmamap_ring_rx);
+		sc->ring_paddr_rx = 0;
+	}
+
+	if (sc->desc_rx) {
 		bus_dmamem_free(sc->dmatag_data_rx, sc->desc_rx,
 		    sc->dmamap_ring_rx);
+		sc->desc_rx = NULL;
+	}
+
+	if (sc->dmatag_data_rx) {
 		bus_dma_tag_destroy(sc->dmatag_data_rx);
-		sc->dmatag_data_rx = 0;
-		sc->dmamap_ring_rx = 0;
-		sc->desc_rx = 0;
+		sc->dmatag_data_rx = NULL;
 	}
 
 	if (sc->dmatag_ring_rx) {
@@ -699,7 +707,7 @@ ece_free_desc_dma_rx(struct ece_softc *sc)
 			    sc->rx_desc[i].dmamap);
 		bus_dmamap_destroy(sc->dmatag_ring_rx, sc->rx_sparemap);
 		bus_dma_tag_destroy(sc->dmatag_ring_rx);
-		sc->dmatag_ring_rx = 0;
+		sc->dmatag_ring_rx = NULL;
 	}
 }