From 63c564da11cbed96ec6cf0b5faf6af0b7e3624d2 Mon Sep 17 00:00:00 2001 From: "Paul E. McKenney" Date: Mon, 13 Dec 2021 21:00:02 -0800 Subject: rcu: Mark ->expmask access in synchronize_rcu_expedited_wait() This commit adds a READ_ONCE() to an access to the rcu_node structure's ->expmask field to prevent compiler mischief. Detected by KCSAN. Signed-off-by: Paul E. McKenney --- kernel/rcu/tree_exp.h | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'kernel/rcu') diff --git a/kernel/rcu/tree_exp.h b/kernel/rcu/tree_exp.h index 1568c8ef185b..60197ea24ceb 100644 --- a/kernel/rcu/tree_exp.h +++ b/kernel/rcu/tree_exp.h @@ -502,7 +502,8 @@ static void synchronize_rcu_expedited_wait(void) if (synchronize_rcu_expedited_wait_once(1)) return; rcu_for_each_leaf_node(rnp) { - for_each_leaf_node_cpu_mask(rnp, cpu, rnp->expmask) { + mask = READ_ONCE(rnp->expmask); + for_each_leaf_node_cpu_mask(rnp, cpu, mask) { rdp = per_cpu_ptr(&rcu_data, cpu); if (rdp->rcu_forced_tick_exp) continue; -- cgit v1.2.3