1 From fabe38ab6b2bd9418350284c63825f13b8a6abba Mon Sep 17 00:00:00 2001
2 From: Masami Hiramatsu <mhiramat@kernel.org>
3 Date: Sun, 24 Feb 2019 01:50:20 +0900
4 Subject: kprobes: Mark ftrace mcount handler functions nokprobe
6 From: Masami Hiramatsu <mhiramat@kernel.org>
8 commit fabe38ab6b2bd9418350284c63825f13b8a6abba upstream.
10 Mark ftrace mcount handler functions nokprobe since
11 probing on these functions with kretprobe pushes
12 return address incorrectly on kretprobe shadow stack.
14 Reported-by: Francis Deslauriers <francis.deslauriers@efficios.com>
15 Tested-by: Andrea Righi <righi.andrea@gmail.com>
16 Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
17 Acked-by: Steven Rostedt <rostedt@goodmis.org>
18 Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
19 Cc: Linus Torvalds <torvalds@linux-foundation.org>
20 Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
21 Cc: Peter Zijlstra <peterz@infradead.org>
22 Cc: Thomas Gleixner <tglx@linutronix.de>
23 Cc: stable@vger.kernel.org
24 Link: http://lkml.kernel.org/r/155094062044.6137.6419622920568680640.stgit@devbox
25 Signed-off-by: Ingo Molnar <mingo@kernel.org>
26 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
29 kernel/trace/ftrace.c | 6 +++++-
30 1 file changed, 5 insertions(+), 1 deletion(-)
32 --- a/kernel/trace/ftrace.c
33 +++ b/kernel/trace/ftrace.c
35 #include <linux/list.h>
36 #include <linux/hash.h>
37 #include <linux/rcupdate.h>
38 +#include <linux/kprobes.h>
40 #include <trace/events/sched.h>
42 @@ -6250,7 +6251,7 @@ void ftrace_reset_array_ops(struct trace
43 tr->ops->func = ftrace_stub;
47 +static nokprobe_inline void
48 __ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip,
49 struct ftrace_ops *ignored, struct pt_regs *regs)
51 @@ -6310,11 +6311,13 @@ static void ftrace_ops_list_func(unsigne
53 __ftrace_ops_list_func(ip, parent_ip, NULL, regs);
55 +NOKPROBE_SYMBOL(ftrace_ops_list_func);
57 static void ftrace_ops_no_ops(unsigned long ip, unsigned long parent_ip)
59 __ftrace_ops_list_func(ip, parent_ip, NULL, NULL);
61 +NOKPROBE_SYMBOL(ftrace_ops_no_ops);
65 @@ -6341,6 +6344,7 @@ static void ftrace_ops_assist_func(unsig
66 preempt_enable_notrace();
67 trace_clear_recursion(bit);
69 +NOKPROBE_SYMBOL(ftrace_ops_assist_func);
72 * ftrace_ops_get_func - get the function a trampoline should call