[GIT pull] core/urgent for 5.7-rc2

[Thomas Gleixner]

Linus,

please pull the latest core/urgent branch from:

   git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git core-urgent-2020-04-19

up to:  40e7d7bdc19e: Merge branch 'urgent-for-mingo' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu into core/urgent


A single bugfix for RCU to prevent taking a lock in NMI context.

Thanks,

	tglx

------------------>
Paul E. McKenney (1):
      rcu: Don't acquire lock in NMI handler in rcu_nmi_enter_common()


 kernel/rcu/tree.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c
index 06548e2ebb72..d9a49cd6065a 100644
--- a/kernel/rcu/tree.c
+++ b/kernel/rcu/tree.c
@@ -825,7 +825,7 @@ static __always_inline void rcu_nmi_enter_common(bool irq)
 			rcu_cleanup_after_idle();
 
 		incby = 1;
-	} else if (tick_nohz_full_cpu(rdp->cpu) &&
+	} else if (irq && tick_nohz_full_cpu(rdp->cpu) &&
 		   rdp->dynticks_nmi_nesting == DYNTICK_IRQ_NONIDLE &&
 		   READ_ONCE(rdp->rcu_urgent_qs) &&
 		   !READ_ONCE(rdp->rcu_forced_tick)) {