From 96050c68be33edef18800ad6748f61f81db81a20 Mon Sep 17 00:00:00 2001 From: "Paul E. McKenney" Date: Sat, 20 Apr 2019 01:40:54 -0700 Subject: rcu: Upgrade sync_exp_work_done() to smp_mb() The sync_exp_work_done() function uses smp_mb__before_atomic(), but there is no obvious atomic in the ensuing code. The ordering is absolutely required for grace periods to work correctly, so this commit upgrades the smp_mb__before_atomic() to smp_mb(). Fixes: 6fba2b3767ea ("rcu: Remove deprecated RCU debugfs tracing code") Reported-by: Andrea Parri Signed-off-by: Paul E. McKenney --- kernel/rcu/tree_exp.h | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) (limited to 'kernel/rcu') diff --git a/kernel/rcu/tree_exp.h b/kernel/rcu/tree_exp.h index 9c990df880d1..d969650a72c6 100644 --- a/kernel/rcu/tree_exp.h +++ b/kernel/rcu/tree_exp.h @@ -259,8 +259,7 @@ static bool sync_exp_work_done(unsigned long s) { if (rcu_exp_gp_seq_done(s)) { trace_rcu_exp_grace_period(rcu_state.name, s, TPS("done")); - /* Ensure test happens before caller kfree(). */ - smp_mb__before_atomic(); /* ^^^ */ + smp_mb(); /* Ensure test happens before caller kfree(). */ return true; } return false; -- cgit