[PATCH 4.9 37/72] kernel/extable.c: mark core_kernel_text notrace

[Greg Kroah-Hartman]

4.9-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Marcin Nowakowski <marcin.nowakowski@xxxxxxxxxx>

commit c0d80ddab89916273cb97114889d3f337bc370ae upstream.

core_kernel_text is used by MIPS in its function graph trace processing,
so having this method traced leads to an infinite set of recursive calls
such as:

  Call Trace:
     ftrace_return_to_handler+0x50/0x128
     core_kernel_text+0x10/0x1b8
     prepare_ftrace_return+0x6c/0x114
     ftrace_graph_caller+0x20/0x44
     return_to_handler+0x10/0x30
     return_to_handler+0x0/0x30
     return_to_handler+0x0/0x30
     ftrace_ops_no_ops+0x114/0x1bc
     core_kernel_text+0x10/0x1b8
     core_kernel_text+0x10/0x1b8
     core_kernel_text+0x10/0x1b8
     ftrace_ops_no_ops+0x114/0x1bc
     core_kernel_text+0x10/0x1b8
     prepare_ftrace_return+0x6c/0x114
     ftrace_graph_caller+0x20/0x44
     (...)

Mark the function notrace to avoid it being traced.

Link: http://lkml.kernel.org/r/1498028607-6765-1-git-send-email-marcin.nowakowski@xxxxxxxxxx
Signed-off-by: Marcin Nowakowski <marcin.nowakowski@xxxxxxxxxx>
Reviewed-by: Masami Hiramatsu <mhiramat@xxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Thomas Meyer <thomas@xxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: Steven Rostedt <rostedt@xxxxxxxxxxx>
Cc: Daniel Borkmann <daniel@xxxxxxxxxxxxx>
Cc: Paul Gortmaker <paul.gortmaker@xxxxxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 kernel/extable.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/kernel/extable.c
+++ b/kernel/extable.c
@@ -66,7 +66,7 @@ static inline int init_kernel_text(unsig
 	return 0;
 }
 
-int core_kernel_text(unsigned long addr)
+int notrace core_kernel_text(unsigned long addr)
 {
 	if (addr >= (unsigned long)_stext &&
 	    addr < (unsigned long)_etext)