queue-4.14/kprobes-mark-ftrace-mcount-handler-functions-nokprobe.patch

   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
   5
   6 From: Masami Hiramatsu <mhiramat@kernel.org>
   7
   8 commit fabe38ab6b2bd9418350284c63825f13b8a6abba upstream.
   9
  10 Mark ftrace mcount handler functions nokprobe since
  11 probing on these functions with kretprobe pushes
  12 return address incorrectly on kretprobe shadow stack.
  13
  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>
  27
  28 ---
  29  kernel/trace/ftrace.c |    6 +++++-
  30  1 file changed, 5 insertions(+), 1 deletion(-)
  31
  32 --- a/kernel/trace/ftrace.c
  33 +++ b/kernel/trace/ftrace.c
  34 @@ -33,6 +33,7 @@
  35  #include <linux/list.h>
  36  #include <linux/hash.h>
  37  #include <linux/rcupdate.h>
  38 +#include <linux/kprobes.h>
  39
  40  #include <trace/events/sched.h>
  41
  42 @@ -6035,7 +6036,7 @@ void ftrace_reset_array_ops(struct trace
  43         tr->ops->func = ftrace_stub;
  44  }
  45
  46 -static inline void
  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)
  50  {
  51 @@ -6098,11 +6099,13 @@ static void ftrace_ops_list_func(unsigne
  52  {
  53         __ftrace_ops_list_func(ip, parent_ip, NULL, regs);
  54  }
  55 +NOKPROBE_SYMBOL(ftrace_ops_list_func);
  56  #else
  57  static void ftrace_ops_no_ops(unsigned long ip, unsigned long parent_ip)
  58  {
  59         __ftrace_ops_list_func(ip, parent_ip, NULL, NULL);
  60  }
  61 +NOKPROBE_SYMBOL(ftrace_ops_no_ops);
  62  #endif
  63
  64  /*
  65 @@ -6132,6 +6135,7 @@ static void ftrace_ops_assist_func(unsig
  66         preempt_enable_notrace();
  67         trace_clear_recursion(bit);
  68  }
  69 +NOKPROBE_SYMBOL(ftrace_ops_assist_func);
  70
  71  /**
  72   * ftrace_ops_get_func - get the function a trampoline should call