From: Masami Hiramatsu <mhiramat@kernel.org>
Date: Tue, 12 Feb 2019 16:11:19 +0000 (+0900)
Subject: x86/kprobes: Prohibit probing on optprobe template code
X-Git-Tag: v4.19.31~105
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=ee7d297fba245621060952d3575dbc7303d0873a;p=platform%2Fkernel%2Flinux-rpi.git

x86/kprobes: Prohibit probing on optprobe template code

commit 0192e6535ebe9af68614198ced4fd6d37b778ebf upstream.

Prohibit probing on optprobe template code, since it is not
a code but a template instruction sequence. If we modify
this template, copied template must be broken.

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andrea Righi <righi.andrea@gmail.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
Fixes: 9326638cbee2 ("kprobes, x86: Use NOKPROBE_SYMBOL() instead of __kprobes annotation")
Link: http://lkml.kernel.org/r/154998787911.31052.15274376330136234452.stgit@devbox
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/arch/x86/kernel/kprobes/opt.c b/arch/x86/kernel/kprobes/opt.c
index 6adf6e6..544bd41 100644
--- a/arch/x86/kernel/kprobes/opt.c
+++ b/arch/x86/kernel/kprobes/opt.c
@@ -141,6 +141,11 @@ asm (
 
 void optprobe_template_func(void);
 STACK_FRAME_NON_STANDARD(optprobe_template_func);
+NOKPROBE_SYMBOL(optprobe_template_func);
+NOKPROBE_SYMBOL(optprobe_template_entry);
+NOKPROBE_SYMBOL(optprobe_template_val);
+NOKPROBE_SYMBOL(optprobe_template_call);
+NOKPROBE_SYMBOL(optprobe_template_end);
 
 #define TMPL_MOVE_IDX \
 	((long)optprobe_template_val - (long)optprobe_template_entry)