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/exit.c | 2 ++ 1 file changed, 2 insertions(+) (limited to 'kernel/exit.c') diff --git a/kernel/exit.c b/kernel/exit.c index ea95ee1b5ef7..0e93b63bbc59 100644 --- a/kernel/exit.c +++ b/kernel/exit.c @@ -761,7 +761,9 @@ void do_exit(long code) */ flush_ptrace_hw_breakpoint(tsk); + TASKS_RCU(preempt_disable()); TASKS_RCU(tasks_rcu_i = __srcu_read_lock(&tasks_rcu_exit_srcu)); + TASKS_RCU(preempt_enable()); exit_notify(tsk, group_dead); proc_exit_connector(tsk); #ifdef CONFIG_NUMA -- cgit