Commit b424ed74 authored by Mao Wenan's avatar Mao Wenan Committed by Greg Kroah-Hartman
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af_packet: set defaule value for tmo

[ Upstream commit b43d1f9f7067c6759b1051e8ecb84e82cef569fe ]

There is softlockup when using TPACKET_V3:
NMI watchdog: BUG: soft lockup - CPU#2 stuck for 60010ms!
(__irq_svc) from [<c0558a0c>] (_raw_spin_unlock_irqrestore+0x44/0x54)
(_raw_spin_unlock_irqrestore) from [<c027b7e8>] (mod_timer+0x210/0x25c)
(mod_timer) from [<c0549c30>]
(prb_retire_rx_blk_timer_expired) from [<c027a7ac>]
(call_timer_fn) from [<c027ab6c>] (run_timer_softirq+0x2d4/0x2fc)
(run_timer_softirq) from [<c021eaf4>] (__do_softirq+0x218/0x318)
(__do_softirq) from [<c021eea0>] (irq_exit+0x88/0xac)
(irq_exit) from [<c0240130>] (msa_irq_exit+0x11c/0x1d4)
(msa_irq_exit) from [<c0209cf0>] (handle_IPI+0x650/0x7f4)
(handle_IPI) from [<c02015bc>] (gic_handle_irq+0x108/0x118)
(gic_handle_irq) from [<c0558ee4>] (__irq_usr+0x44/0x5c)

If __ethtool_get_link_ksettings() is failed in
prb_calc_retire_blk_tmo(), msec and tmo will be zero, so tov_in_jiffies
is zero and the timer expire for retire_blk_timer is turn to
mod_timer(&pkc->retire_blk_timer, jiffies + 0),
which will trigger cpu usage of softirq is 100%.

Fixes: f6fb8f10

 ("af-packet: TPACKET_V3 flexible buffer implementation.")
Tested-by: default avatarXiao Jiangfeng <>
Signed-off-by: default avatarMao Wenan <>
Signed-off-by: default avatarDavid S. Miller <>
Signed-off-by: default avatarGreg Kroah-Hartman <>
parent 408d9794
......@@ -587,7 +587,8 @@ static int prb_calc_retire_blk_tmo(struct packet_sock *po,
msec = 1;
div = speed / 1000;
} else
mbits = (blk_size_in_bytes * 8) / (1024 * 1024);
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