[for-next][PATCH 6/6] uprobes: Use synchronize_rcu() not synchronize_sched()

From: Steven Rostedt
Date: Thu Aug 09 2018 - 17:07:05 EST


From: "Steven Rostedt (VMware)" <rostedt@xxxxxxxxxxx>

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.

Cc: stable@xxxxxxxxxxxxxxx
Fixes: 70ed91c6ec7f8 ("tracing/uprobes: Support ftrace_event_file base multibuffer")
Signed-off-by: Steven Rostedt (VMware) <rostedt@xxxxxxxxxxx>
---
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))
--
2.18.0