uprobes: Use synchronize_rcu() not synchronize_sched()

While debugging another bug, I was looking at all the synchronize*()
functions being used in kernel/trace, and noticed that trace_uprobes was
using synchronize_sched(), with a comment to synchronize with
{u,ret}_probe_trace_func(). When looking at those functions, the data is
protected with "rcu_read_lock()" and not with "rcu_read_lock_sched()". This
is using the wrong synchronize_*() function.

Link: http://lkml.kernel.org/r/20180809160553.469e1e32@gandalf.local.home

Cc: stable@vger.kernel.org
Fixes: 70ed91c6ec ("tracing/uprobes: Support ftrace_event_file base multibuffer")
Acked-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
This commit is contained in:
Steven Rostedt (VMware) 2018-08-09 15:37:59 -04:00
parent e0a568dcd1
commit 016f8ffc48

View file

@ -952,7 +952,7 @@ probe_event_disable(struct trace_uprobe *tu, struct trace_event_file *file)
list_del_rcu(&link->list); list_del_rcu(&link->list);
/* synchronize with u{,ret}probe_trace_func */ /* synchronize with u{,ret}probe_trace_func */
synchronize_sched(); synchronize_rcu();
kfree(link); kfree(link);
if (!list_empty(&tu->tp.files)) if (!list_empty(&tu->tp.files))