[PATCH 02/16] drivers, net, ethernet: convert mtk_eth.dma_refcnt from atomic_t to refcount_t
From: elena.reshetova@intel.com (Elena Reshetova)
Date: 2017-03-28 09:00:44
Also in:
linux-hams, linux-rdma, linux-wireless, lkml, netdev
Subsystem:
mediatek ethernet driver, networking drivers, the rest · Maintainers:
Felix Fietkau, Lorenzo Bianconi, Andrew Lunn, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
refcount_t type and corresponding API should be used instead of atomic_t when the variable is used as a reference counter. This allows to avoid accidental refcounter overflows that might lead to use-after-free situations. Signed-off-by: Elena Reshetova <elena.reshetova@intel.com> Signed-off-by: Hans Liljestrand <redacted> Signed-off-by: Kees Cook <redacted> Signed-off-by: David Windsor <redacted> --- drivers/net/ethernet/mediatek/mtk_eth_soc.c | 8 +++++--- drivers/net/ethernet/mediatek/mtk_eth_soc.h | 4 +++- 2 files changed, 8 insertions(+), 4 deletions(-)
diff --git a/drivers/net/ethernet/mediatek/mtk_eth_soc.c b/drivers/net/ethernet/mediatek/mtk_eth_soc.c
index bf6317e..d27f9d9 100644
--- a/drivers/net/ethernet/mediatek/mtk_eth_soc.c
+++ b/drivers/net/ethernet/mediatek/mtk_eth_soc.c@@ -1725,7 +1725,7 @@ static int mtk_open(struct net_device *dev) struct mtk_eth *eth = mac->hw; /* we run 2 netdevs on the same dma ring so we only bring it up once */ - if (!atomic_read(ð->dma_refcnt)) { + if (!refcount_read(ð->dma_refcnt)) { int err = mtk_start_dma(eth); if (err)
@@ -1735,8 +1735,10 @@ static int mtk_open(struct net_device *dev) napi_enable(ð->rx_napi); mtk_irq_enable(eth, MTK_QDMA_INT_MASK, MTK_TX_DONE_INT); mtk_irq_enable(eth, MTK_PDMA_INT_MASK, MTK_RX_DONE_INT); + refcount_set(ð->dma_refcnt, 1); } - atomic_inc(ð->dma_refcnt); + else + refcount_inc(ð->dma_refcnt); phy_start(dev->phydev); netif_start_queue(dev);
@@ -1776,7 +1778,7 @@ static int mtk_stop(struct net_device *dev) phy_stop(dev->phydev); /* only shutdown DMA if this is the last user */ - if (!atomic_dec_and_test(ð->dma_refcnt)) + if (!refcount_dec_and_test(ð->dma_refcnt)) return 0; mtk_irq_disable(eth, MTK_QDMA_INT_MASK, MTK_TX_DONE_INT);
diff --git a/drivers/net/ethernet/mediatek/mtk_eth_soc.h b/drivers/net/ethernet/mediatek/mtk_eth_soc.h
index 99b1c8e..e5b99b7 100644
--- a/drivers/net/ethernet/mediatek/mtk_eth_soc.h
+++ b/drivers/net/ethernet/mediatek/mtk_eth_soc.h@@ -15,6 +15,8 @@ #ifndef MTK_ETH_H #define MTK_ETH_H +#include <linux/refcount.h> + #define MTK_QDMA_PAGE_SIZE 2048 #define MTK_MAX_RX_LENGTH 1536 #define MTK_TX_DMA_BUF_LEN 0x3fff
@@ -541,7 +543,7 @@ struct mtk_eth { struct regmap *pctl; u32 chip_id; bool hwlro; - atomic_t dma_refcnt; + refcount_t dma_refcnt; struct mtk_tx_ring tx_ring; struct mtk_rx_ring rx_ring[MTK_MAX_RX_RING_NUM]; struct napi_struct tx_napi;
--
2.7.4