Re: [PATCH] net/tg3: fix race condition in tg3_reset_task_cancel()
From: Michael Chan <michael.chan@broadcom.com>
Date: 2023-10-03 09:37:53
On Mon, Oct 2, 2023 at 11:55 AM Thinh Tran [off-list ref] wrote:
quoted hunk ↗ jump to hunk
during the EEH error injection tests on the 4-port 1 GbE NetXtreme BCM5719 Gigabit Ethernet PCIe adapter, a race condition was observed in the process of resetting and setting the driver flag to TX_RECOVERY_PENDING between tg3_reset_task_cancel() and tg3_tx_recover(). As a result, it occasionally leads to transmit timeouts and the subsequent disabling of all the driver's interfaces. [12046.886221] NETDEV WATCHDOG: eth16 (tg3): transmit queue 0 timed out [12046.886238] WARNING: CPU: 7 PID: 0 at ../net/sched/sch_generic.c:478 dev_watchdog+0x42c/0x440 [12046.886247] Modules linked in: tg3 libphy nfsv3 nfs_acl ....... .......... [12046.886571] tg3 0021:01:00.0 eth16: transmit timed out, resetting ........... [12046.966175] tg3 0021:01:00.1 eth15: transmit timed out, resetting ........... [12046.981584] tg3 0021:01:00.2 eth14: transmit timed out, resetting ........... [12047.056165] tg3 0021:01:00.3 eth13: transmit timed out, resetting Fixing this issue by taking the spinlock when modifying the driver flag Fixes: 6c4ca03bd890 ("net/tg3: resolve deadlock in tg3_reset_task() during EEH") Signed-off-by: Thinh Tran <redacted> Tested-by: Venkata Sai Duggi <redacted> --- drivers/net/ethernet/broadcom/tg3.c | 5 +++++ 1 file changed, 5 insertions(+)diff --git a/drivers/net/ethernet/broadcom/tg3.c b/drivers/net/ethernet/broadcom/tg3.c index 14b311196b8f..f4558762f9de 100644 --- a/drivers/net/ethernet/broadcom/tg3.c +++ b/drivers/net/ethernet/broadcom/tg3.c@@ -6507,7 +6507,9 @@ static void tg3_tx_recover(struct tg3 *tp) "Please report the problem to the driver maintainer " "and include system chipset information.\n"); + tg3_full_lock(tp, 0); tg3_flag_set(tp, TX_RECOVERY_PENDING); + tg3_full_unlock(tp);
tg3_flag_set() calls set_bit() which is atomic. The same is true for tg3_flag_clear(). Maybe we just need some smp_mb__after_atomic() or similar memory barriers.
quoted hunk ↗ jump to hunk
} static inline u32 tg3_tx_avail(struct tg3_napi *tnapi)@@ -7210,7 +7212,10 @@ static inline void tg3_reset_task_cancel(struct tg3 *tp) { if (test_and_clear_bit(TG3_FLAG_RESET_TASK_PENDING, tp->tg3_flags)) cancel_work_sync(&tp->reset_task); + + tg3_full_lock(tp, 0); tg3_flag_clear(tp, TX_RECOVERY_PENDING); + tg3_full_unlock(tp); } static int tg3_poll_msix(struct napi_struct *napi, int budget) --2.25.1
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