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authorMichael Chan <michael.chan@broadcom.com>2018-05-03 20:04:27 -0400
committerDavid S. Miller <davem@davemloft.net>2018-05-04 12:57:17 -0400
commitd89a2adb8bfe6f8949ff389acdb9fa298b6e8e12 (patch)
tree49dfd594495bc0d5b9bb790b18841e276c0ef68d /drivers/net/ethernet/broadcom/tg3.c
parentnsh: fix infinite loop (diff)
downloadlinux-dev-d89a2adb8bfe6f8949ff389acdb9fa298b6e8e12.tar.xz
linux-dev-d89a2adb8bfe6f8949ff389acdb9fa298b6e8e12.zip
tg3: Fix vunmap() BUG_ON() triggered from tg3_free_consistent().
tg3_free_consistent() calls dma_free_coherent() to free tp->hw_stats under spinlock and can trigger BUG_ON() in vunmap() because vunmap() may sleep. Fix it by removing the spinlock and relying on the TG3_FLAG_INIT_COMPLETE flag to prevent race conditions between tg3_get_stats64() and tg3_free_consistent(). TG3_FLAG_INIT_COMPLETE is always cleared under tp->lock before tg3_free_consistent() and therefore tg3_get_stats64() can safely access tp->hw_stats under tp->lock if TG3_FLAG_INIT_COMPLETE is set. Fixes: f5992b72ebe0 ("tg3: Fix race condition in tg3_get_stats64().") Reported-by: Zumeng Chen <zumeng.chen@gmail.com> Signed-off-by: Michael Chan <michael.chan@broadcom.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers/net/ethernet/broadcom/tg3.c')
-rw-r--r--drivers/net/ethernet/broadcom/tg3.c9
1 files changed, 5 insertions, 4 deletions
diff --git a/drivers/net/ethernet/broadcom/tg3.c b/drivers/net/ethernet/broadcom/tg3.c
index 08bbb639be1a..9f59b1270a7c 100644
--- a/drivers/net/ethernet/broadcom/tg3.c
+++ b/drivers/net/ethernet/broadcom/tg3.c
@@ -8733,14 +8733,15 @@ static void tg3_free_consistent(struct tg3 *tp)
tg3_mem_rx_release(tp);
tg3_mem_tx_release(tp);
- /* Protect tg3_get_stats64() from reading freed tp->hw_stats. */
- tg3_full_lock(tp, 0);
+ /* tp->hw_stats can be referenced safely:
+ * 1. under rtnl_lock
+ * 2. or under tp->lock if TG3_FLAG_INIT_COMPLETE is set.
+ */
if (tp->hw_stats) {
dma_free_coherent(&tp->pdev->dev, sizeof(struct tg3_hw_stats),
tp->hw_stats, tp->stats_mapping);
tp->hw_stats = NULL;
}
- tg3_full_unlock(tp);
}
/*
@@ -14178,7 +14179,7 @@ static void tg3_get_stats64(struct net_device *dev,
struct tg3 *tp = netdev_priv(dev);
spin_lock_bh(&tp->lock);
- if (!tp->hw_stats) {
+ if (!tp->hw_stats || !tg3_flag(tp, INIT_COMPLETE)) {
*stats = tp->net_stats_prev;
spin_unlock_bh(&tp->lock);
return;