From: "Paul E. McKenney" <paulmck@xxxxxxxxxx> The load of the srcu_struct structure's ->srcu_gp_seq field in srcu_funnel_gp_start() is lockless, so this commit adds the requisite READ_ONCE(). This data race was reported by KCSAN. Signed-off-by: Paul E. McKenney <paulmck@xxxxxxxxxx> --- kernel/rcu/srcutree.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/kernel/rcu/srcutree.c b/kernel/rcu/srcutree.c index 119a373..90ab475 100644 --- a/kernel/rcu/srcutree.c +++ b/kernel/rcu/srcutree.c @@ -678,7 +678,7 @@ static void srcu_funnel_gp_start(struct srcu_struct *ssp, struct srcu_data *sdp, /* If grace period not already done and none in progress, start it. */ if (!rcu_seq_done(&ssp->srcu_gp_seq, s) && - rcu_seq_state(ssp->srcu_gp_seq) == SRCU_STATE_IDLE) { + rcu_seq_state(READ_ONCE(ssp->srcu_gp_seq)) == SRCU_STATE_IDLE) { WARN_ON_ONCE(ULONG_CMP_GE(ssp->srcu_gp_seq, ssp->srcu_gp_seq_needed)); srcu_gp_start(ssp); if (likely(srcu_init_done)) -- 2.9.5