From: Masami Hiramatsu <mhiramat@kernel.org>
Date: Sat, 23 Feb 2019 16:50:20 +0000 (+0900)
Subject: kprobes: Mark ftrace mcount handler functions nokprobe
X-Git-Tag: v3.16.72~61
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=51d68a4c8e5309c4f8bdcb71d8535215246210f8;p=thirdparty%2Fkernel%2Fstable.git

kprobes: Mark ftrace mcount handler functions nokprobe

commit fabe38ab6b2bd9418350284c63825f13b8a6abba upstream.

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>
Link: http://lkml.kernel.org/r/155094062044.6137.6419622920568680640.stgit@devbox
Signed-off-by: Ingo Molnar <mingo@kernel.org>
[bwh: Backported to 3.16: there is no ftrace_ops_assist_func()]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
---

diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index 8ee705e1d4726..c59d43d54d321 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -32,6 +32,7 @@
 #include <linux/list.h>
 #include <linux/hash.h>
 #include <linux/rcupdate.h>
+#include <linux/kprobes.h>
 
 #include <trace/events/sched.h>
 
@@ -4508,7 +4509,7 @@ static struct ftrace_ops control_ops = {
 	INIT_OPS_HASH(control_ops)
 };
 
-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)
 {
@@ -4561,11 +4562,13 @@ 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
 
 static void clear_ftrace_swapper(void)