From: "Steven Rostedt (VMware)" rostedt@goodmis.org
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: 70ed91c6ec7f8 ("tracing/uprobes: Support ftrace_event_file base multibuffer") Acked-by: Oleg Nesterov oleg@redhat.com Signed-off-by: Steven Rostedt (VMware) rostedt@goodmis.org --- kernel/trace/trace_uprobe.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/kernel/trace/trace_uprobe.c b/kernel/trace/trace_uprobe.c index bf89a51e740d..ac02fafc9f1b 100644 --- a/kernel/trace/trace_uprobe.c +++ b/kernel/trace/trace_uprobe.c @@ -952,7 +952,7 @@ probe_event_disable(struct trace_uprobe *tu, struct trace_event_file *file)
list_del_rcu(&link->list); /* synchronize with u{,ret}probe_trace_func */ - synchronize_sched(); + synchronize_rcu(); kfree(link);
if (!list_empty(&tu->tp.files))