5.10-stable review patch. If anyone has any objections, please let me know.
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From: Heiner Kallweit hkallweit1@gmail.com
[ Upstream commit 3a689e34973e8717cd57991c6fcf527dc56062b5 ]
tp->dirty_tx isn't changed outside rtl_tx(). Therefore I see no need to guarantee a specific order of reading tp->dirty_tx and tp->cur_tx. Having said that we can remove the memory barrier. In addition use READ_ONCE() when reading tp->cur_tx because it can change in parallel to rtl_tx().
Signed-off-by: Heiner Kallweit hkallweit1@gmail.com Link: https://lore.kernel.org/r/2264563a-fa9e-11b0-2c42-31bc6b8e2790@gmail.com Signed-off-by: Jakub Kicinski kuba@kernel.org Stable-dep-of: c71e3a5cffd5 ("r8169: Fix possible ring buffer corruption on fragmented Tx packets.") Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/net/ethernet/realtek/r8169_main.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-)
diff --git a/drivers/net/ethernet/realtek/r8169_main.c b/drivers/net/ethernet/realtek/r8169_main.c index c29d43c5f4504..84c8362a65cd1 100644 --- a/drivers/net/ethernet/realtek/r8169_main.c +++ b/drivers/net/ethernet/realtek/r8169_main.c @@ -4472,9 +4472,8 @@ static void rtl_tx(struct net_device *dev, struct rtl8169_private *tp, unsigned int dirty_tx, tx_left, bytes_compl = 0, pkts_compl = 0;
dirty_tx = tp->dirty_tx; - smp_rmb();
- for (tx_left = tp->cur_tx - dirty_tx; tx_left > 0; tx_left--) { + for (tx_left = READ_ONCE(tp->cur_tx) - dirty_tx; tx_left; tx_left--) { unsigned int entry = dirty_tx % NUM_TX_DESC; struct sk_buff *skb = tp->tx_skb[entry].skb; u32 status;