From: Alexei Starovoitov <ast@plumgrid.com>
Date: Tue, 16 Jun 2015 17:35:18 +0000 (-0700)
Subject: rcu: Make rcu_is_watching() really notrace
X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=46f00d18fca42cc954c2e9e99a48b6f3a7741ed7;p=linux-beck.git

rcu: Make rcu_is_watching() really notrace

Although rcu_is_watching() is marked notrace, it invokes preempt_disable()
and preempt_enable(), both of which can be traced.  This defeats the
purpose of the notrace on rcu_is_watching(), so this commit substitutes
preempt_disable_notrace() and preempt_enable_notrace().

Signed-off-by: Alexei Starovoitov <ast@plumgrid.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
---

diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c
index 9629298eea24..cb64d7e13d24 100644
--- a/kernel/rcu/tree.c
+++ b/kernel/rcu/tree.c
@@ -978,9 +978,9 @@ bool notrace rcu_is_watching(void)
 {
 	bool ret;
 
-	preempt_disable();
+	preempt_disable_notrace();
 	ret = __rcu_is_watching();
-	preempt_enable();
+	preempt_enable_notrace();
 	return ret;
 }
 EXPORT_SYMBOL_GPL(rcu_is_watching);