[PATCH v2 2/3] kprobes: Mark ftrace mcount handler functions nokprobe

[Masami Hiramatsu]

Mark ftrace mcount handler functions nokprobe since
probing on these functions with kretprobe pushes
return address incorrectly on kretprobe shadow stack.

Signed-off-by: Masami Hiramatsu <mhira...@kernel.org>
Reported-by: Francis Deslauriers <francis.deslauri...@efficios.com>
Tested-by: Andrea Righi <righi.and...@gmail.com>
Cc: sta...@vger.kernel.org
---
 - Changes in v2:
   Fix to include kprobes.h (Thanks Andrea!)
---
 kernel/trace/ftrace.c |    6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index f0ff24173a0b..b0774388d52b 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -34,6 +34,7 @@
 #include <linux/list.h>
 #include <linux/hash.h>
 #include <linux/rcupdate.h>
+#include <linux/kprobes.h>
 
 #include <trace/events/sched.h>
 
@@ -6250,7 +6251,7 @@ void ftrace_reset_array_ops(struct trace_array *tr)
        tr->ops->func = ftrace_stub;
 }
 
-static inline void
+static nokprobe_inline void
 __ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip,
                       struct ftrace_ops *ignored, struct pt_regs *regs)
 {
@@ -6310,11 +6311,13 @@ static void ftrace_ops_list_func(unsigned long ip, 
unsigned long parent_ip,
 {
        __ftrace_ops_list_func(ip, parent_ip, NULL, regs);
 }
+NOKPROBE_SYMBOL(ftrace_ops_list_func);
 #else
 static void ftrace_ops_no_ops(unsigned long ip, unsigned long parent_ip)
 {
        __ftrace_ops_list_func(ip, parent_ip, NULL, NULL);
 }
+NOKPROBE_SYMBOL(ftrace_ops_no_ops);
 #endif
 
 /*
@@ -6341,6 +6344,7 @@ static void ftrace_ops_assist_func(unsigned long ip, 
unsigned long parent_ip,
        preempt_enable_notrace();
        trace_clear_recursion(bit);
 }
+NOKPROBE_SYMBOL(ftrace_ops_assist_func);
 
 /**
  * ftrace_ops_get_func - get the function a trampoline should call