From 49f5903b473c5f63f3b57856d1bd4593db0a2eef Mon Sep 17 00:00:00 2001 From: "Paul E. McKenney" Date: Tue, 1 Sep 2015 00:42:57 -0700 Subject: rcu: Move preemption disabling out of __srcu_read_lock() Currently, __srcu_read_lock() cannot be invoked from restricted environments because it contains calls to preempt_disable() and preempt_enable(), both of which can invoke lockdep, which is a bad idea in some restricted execution modes. This commit therefore moves the preempt_disable() and preempt_enable() from __srcu_read_lock() to srcu_read_lock(). It also inserts the preempt_disable() and preempt_enable() around the call to __srcu_read_lock() in do_exit(). Signed-off-by: Paul E. McKenney Reviewed-by: Josh Triplett --- kernel/rcu/srcu.c | 2 -- 1 file changed, 2 deletions(-) (limited to 'kernel/rcu') diff --git a/kernel/rcu/srcu.c b/kernel/rcu/srcu.c index 9e6122540d28..a63a1ea5a41b 100644 --- a/kernel/rcu/srcu.c +++ b/kernel/rcu/srcu.c @@ -298,11 +298,9 @@ int __srcu_read_lock(struct srcu_struct *sp) int idx; idx = READ_ONCE(sp->completed) & 0x1; - preempt_disable(); __this_cpu_inc(sp->per_cpu_ref->c[idx]); smp_mb(); /* B */ /* Avoid leaking the critical section. */ __this_cpu_inc(sp->per_cpu_ref->seq[idx]); - preempt_enable(); return idx; } EXPORT_SYMBOL_GPL(__srcu_read_lock); -- cgit v1.2.3