Merge tag 'trace-v4.14-rc1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rosted...

[sfrench/cifs-2.6.git] / kernel / rcu / tree.c

diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c
index 1250e4bd4b85e690c7db2b061a87599e8651a606..0c44c7b42e6d50bbb67ae47cbe257a734020b16c 100644 (file)
--- a/kernel/rcu/tree.c
+++ b/kernel/rcu/tree.c
@@ -882,6 +882,11 @@ void rcu_irq_exit(void)
 
        RCU_LOCKDEP_WARN(!irqs_disabled(), "rcu_irq_exit() invoked with irqs enabled!!!");
        rdtp = this_cpu_ptr(&rcu_dynticks);
+
+       /* Page faults can happen in NMI handlers, so check... */
+       if (READ_ONCE(rdtp->dynticks_nmi_nesting))
+               return;
+
        WARN_ON_ONCE(IS_ENABLED(CONFIG_RCU_EQS_DEBUG) &&
                     rdtp->dynticks_nesting < 1);
        if (rdtp->dynticks_nesting <= 1) {
@@ -1015,6 +1020,11 @@ void rcu_irq_enter(void)
 
        RCU_LOCKDEP_WARN(!irqs_disabled(), "rcu_irq_enter() invoked with irqs enabled!!!");
        rdtp = this_cpu_ptr(&rcu_dynticks);
+
+       /* Page faults can happen in NMI handlers, so check... */
+       if (READ_ONCE(rdtp->dynticks_nmi_nesting))
+               return;
+
        oldval = rdtp->dynticks_nesting;
        rdtp->dynticks_nesting++;
        WARN_ON_ONCE(IS_ENABLED(CONFIG_RCU_EQS_DEBUG) &&