[tip:perf/core] x86/kprobes: Prohibit probing on optprobe template code

tip-bot for Masami Hiramatsu
2019-02-13T09:00:54Z

Commit-ID: 0192e6535ebe9af68614198ced4fd6d37b778ebf
Gitweb: https://git.kernel.org/tip/0192e6535ebe9af68614198ced4fd6d37b778ebf
Author: Masami Hiramatsu <mhiramat@kernel.org>
AuthorDate: Wed, 13 Feb 2019 01:11:19 +0900
Committer: Ingo Molnar <mingo@kernel.org>
CommitDate: Wed, 13 Feb 2019 08:16:39 +0100

x86/kprobes: Prohibit probing on optprobe template code

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>
---
arch/x86/kernel/kprobes/opt.c | 5 +++++
1 file changed, 5 insertions(+)

diff --git a/arch/x86/kernel/kprobes/opt.c b/arch/x86/kernel/kprobes/opt.c
index 6adf6e6c2933..544bd41a514c 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)