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| author | Paul E. McKenney <paulmck@linux.vnet.ibm.com> | 2014-08-14 10:28:23 -0700 |
|---|---|---|
| committer | Paul E. McKenney <paulmck@linux.vnet.ibm.com> | 2014-09-07 16:18:20 -0700 |
| commit | 73a860cd58a1eb258e889b615cebf738ab33aa23 (patch) | |
| tree | 9eacb2ac5f6331f3249778c685da7f26c8ed0488 /kernel/rcu | |
| parent | 2aa792e6faf1a00f5accf1f69e87e11a390ba2cd (diff) | |
| download | linux-73a860cd58a1eb258e889b615cebf738ab33aa23.tar.bz2 | |
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 <oleg@redhat.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Diffstat (limited to 'kernel/rcu')
| -rw-r--r-- | kernel/rcu/tree.c | 4 | ||||
| -rw-r--r-- | kernel/rcu/tree_plugin.h | 6 |
2 files changed, 5 insertions, 5 deletions
diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c index 9e83cd9a32f1..3e002c1cb441 100644 --- a/kernel/rcu/tree.c +++ b/kernel/rcu/tree.c @@ -1796,7 +1796,7 @@ static int __noreturn rcu_gp_kthread(void *arg) if (rcu_gp_init(rsp)) break; cond_resched(); - flush_signals(current); + WARN_ON(signal_pending(current)); trace_rcu_grace_period(rsp->name, ACCESS_ONCE(rsp->gpnum), TPS("reqwaitsig")); @@ -1842,7 +1842,7 @@ static int __noreturn rcu_gp_kthread(void *arg) } else { /* Deal with stray signal. */ cond_resched(); - flush_signals(current); + WARN_ON(signal_pending(current)); trace_rcu_grace_period(rsp->name, ACCESS_ONCE(rsp->gpnum), TPS("fqswaitsig")); 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); } } |