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-rw-r--r--kernel/rcu/tree_exp.h2
-rw-r--r--kernel/rcu/tree_plugin.h4
2 files changed, 4 insertions, 2 deletions
diff --git a/kernel/rcu/tree_exp.h b/kernel/rcu/tree_exp.h
index 3b7abb58157d..8239b39d945b 100644
--- a/kernel/rcu/tree_exp.h
+++ b/kernel/rcu/tree_exp.h
@@ -643,7 +643,7 @@ static void synchronize_rcu_expedited_wait(void)
"O."[!!cpu_online(cpu)],
"o."[!!(rdp->grpmask & rnp->expmaskinit)],
"N."[!!(rdp->grpmask & rnp->expmaskinitnext)],
- "D."[!!(rdp->cpu_no_qs.b.exp)]);
+ "D."[!!data_race(rdp->cpu_no_qs.b.exp)]);
}
}
pr_cont(" } %lu jiffies s: %lu root: %#lx/%c\n",
diff --git a/kernel/rcu/tree_plugin.h b/kernel/rcu/tree_plugin.h
index 7b0fe741a088..41021080ad25 100644
--- a/kernel/rcu/tree_plugin.h
+++ b/kernel/rcu/tree_plugin.h
@@ -257,6 +257,8 @@ static void rcu_preempt_ctxt_queue(struct rcu_node *rnp, struct rcu_data *rdp)
* GP should not be able to end until we report, so there should be
* no need to check for a subsequent expedited GP. (Though we are
* still in a quiescent state in any case.)
+ *
+ * Interrupts are disabled, so ->cpu_no_qs.b.exp cannot change.
*/
if (blkd_state & RCU_EXP_BLKD && rdp->cpu_no_qs.b.exp)
rcu_report_exp_rdp(rdp);
@@ -941,7 +943,7 @@ notrace void rcu_preempt_deferred_qs(struct task_struct *t)
{
struct rcu_data *rdp = this_cpu_ptr(&rcu_data);
- if (rdp->cpu_no_qs.b.exp)
+ if (READ_ONCE(rdp->cpu_no_qs.b.exp))
rcu_report_exp_rdp(rdp);
}