From 73a860cd58a1eb258e889b615cebf738ab33aa23 Mon Sep 17 00:00:00 2001 From: "Paul E. McKenney" Date: Thu, 14 Aug 2014 10:28:23 -0700 Subject: rcu: Replace flush_signals() with WARN_ON(signal_pending()) Currently, when RCU awakens from a wait_event_interruptible() that might have awakened prematurely, it does a flush_signals(). This is done on the off-chance that someone figured out how to deliver a signal to a kthread, which is supposed to be impossible. Given that this is supposed to be impossible, this commit changes the flush_signals() calls into WARN_ON(signal_pending()). Reported-by: Oleg Nesterov Signed-off-by: Paul E. McKenney --- kernel/rcu/tree_plugin.h | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) (limited to 'kernel/rcu/tree_plugin.h') diff --git a/kernel/rcu/tree_plugin.h b/kernel/rcu/tree_plugin.h index d67cc5c375c5..bbb0a0cd091b 100644 --- a/kernel/rcu/tree_plugin.h +++ b/kernel/rcu/tree_plugin.h @@ -2237,7 +2237,7 @@ static void rcu_nocb_wait_gp(struct rcu_data *rdp) (d = ULONG_CMP_GE(ACCESS_ONCE(rnp->completed), c))); if (likely(d)) break; - flush_signals(current); + WARN_ON(signal_pending(current)); trace_rcu_future_gp(rnp, rdp, c, TPS("ResumeWait")); } trace_rcu_future_gp(rnp, rdp, c, TPS("EndWait")); @@ -2296,7 +2296,7 @@ wait_again: if (!rcu_nocb_poll) trace_rcu_nocb_wake(my_rdp->rsp->name, my_rdp->cpu, "WokeEmpty"); - flush_signals(current); + WARN_ON(signal_pending(current)); schedule_timeout_interruptible(1); /* Rescan in case we were a victim of memory ordering. */ @@ -2375,7 +2375,7 @@ static void nocb_follower_wait(struct rcu_data *rdp) if (!rcu_nocb_poll) trace_rcu_nocb_wake(rdp->rsp->name, rdp->cpu, "WokeEmpty"); - flush_signals(current); + WARN_ON(signal_pending(current)); schedule_timeout_interruptible(1); } } -- cgit v1.2.3