[for-linus][PATCH 03/12] ftrace: Protect direct_functions in ftrace_find_rec_direct
Steven Rostedt <[email protected]>
| Newsgroups | org.kernel.vger.stable,org.kernel.vger.linux-kernel |
|---|---|
| Message-ID | <[email protected]> |
From: Leon Hwang <[email protected]> Fix accessing the __rcu pointer direct_functions with RCU protection. Cc: [email protected] Link: https://patch.msgid.link/[email protected] Fixes: d05cb470663a ("ftrace: Fix modification of direct_function hash while in use") Acked-by: Jiri Olsa <[email protected]> Suggested-by: Steven Rostedt <[email protected]> Signed-off-by: Leon Hwang <[email protected]> Signed-off-by: Steven Rostedt <[email protected]> --- kernel/trace/ftrace.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index 6c47a94f5924..c5d1d0d42ccc 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -2645,7 +2645,8 @@ unsigned long ftrace_find_rec_direct(unsigned long ip) { struct ftrace_func_entry *entry; - entry = __ftrace_lookup_ip(direct_functions, ip); + guard(preempt_notrace)(); + entry = __ftrace_lookup_ip(rcu_dereference_sched(direct_functions), ip); if (!entry) return 0; -- 2.53.0