3.2-stable review patch. If anyone has any objections, please let me know. ------------------ From: "Steven Rostedt (Red Hat)" <rostedt@xxxxxxxxxxx> commit 740466bc89ad8bd5afcc8de220f715f62b21e365 upstream. Because function tracing is very invasive, and can even trace calls to rcu_read_lock(), RCU access in function tracing is done with preempt_disable_notrace(). This requires a synchronize_sched() for updates and not a synchronize_rcu(). Function probes (traceon, traceoff, etc) must be freed after a synchronize_sched() after its entry has been removed from the hash. But call_rcu() is used. Fix this by using call_rcu_sched(). Also fix the usage to use hlist_del_rcu() instead of hlist_del(). Cc: Paul McKenney <paulmck@xxxxxxxxxxxxxxxxxx> Signed-off-by: Steven Rostedt <rostedt@xxxxxxxxxxx> Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx> --- kernel/trace/ftrace.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -2725,8 +2725,8 @@ __unregister_ftrace_function_probe(char continue; } - hlist_del(&entry->node); - call_rcu(&entry->rcu, ftrace_free_entry_rcu); + hlist_del_rcu(&entry->node); + call_rcu_sched(&entry->rcu, ftrace_free_entry_rcu); } } __disable_ftrace_function_probe(); -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html