| From | Sasha Levin <> | Subject | [PATCH AUTOSEL 5.4 036/130] r8169: use READ_ONCE in rtl_tx_slots_avail | Date | Tue, 22 Dec 2020 21:16:39 -0500 |
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From: Heiner Kallweit <hkallweit1@gmail.com>
[ Upstream commit 95f3c5458dfa5856bb110e31d156e00d894d0134 ]
tp->dirty_tx and tp->cur_tx may be changed by a racing rtl_tx() or rtl8169_start_xmit(). Use READ_ONCE() to annotate the races and ensure that the compiler doesn't use cached values.
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com> Link: https://lore.kernel.org/r/5676fee3-f6b4-84f2-eba5-c64949a371ad@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org> --- drivers/net/ethernet/realtek/r8169_main.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/drivers/net/ethernet/realtek/r8169_main.c b/drivers/net/ethernet/realtek/r8169_main.c index fd5adb0c54d29..fca8252b4f21d 100644 --- a/drivers/net/ethernet/realtek/r8169_main.c +++ b/drivers/net/ethernet/realtek/r8169_main.c @@ -5856,7 +5856,8 @@ static bool rtl8169_tso_csum_v2(struct rtl8169_private *tp, static bool rtl_tx_slots_avail(struct rtl8169_private *tp, unsigned int nr_frags) { - unsigned int slots_avail = tp->dirty_tx + NUM_TX_DESC - tp->cur_tx; + unsigned int slots_avail = READ_ONCE(tp->dirty_tx) + NUM_TX_DESC + - READ_ONCE(tp->cur_tx); /* A skbuff with nr_frags needs nr_frags+1 entries in the tx queue */ return slots_avail > nr_frags; -- 2.27.0
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