kprobes: Mark ftrace mcount handler functions nokprobe

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

Reported-by: Francis Deslauriers <francis.deslauriers@efficios.com>
Tested-by: Andrea Righi <righi.andrea@gmail.com>
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
Link: http://lkml.kernel.org/r/155094062044.6137.6419622920568680640.stgit@devbox
Signed-off-by: Ingo Molnar <mingo@kernel.org>

1 files changed, 5 insertions, 1 deletions

diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index 26c8ca9bd06b..b920358dd8f7 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -33,6 +33,7 @@
 #include <linux/list.h>
 #include <linux/hash.h>
 #include <linux/rcupdate.h>
+#include <linux/kprobes.h>
 
 #include <trace/events/sched.h>
 
@@ -6246,7 +6247,7 @@ 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)
 {
@@ -6306,11 +6307,13 @@ 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
 
 /*
@@ -6337,6 +6340,7 @@ 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