[ARM] 5421/1: ftrace: fix crash due to tracing of __naked functions

This is a fix for the following crash observed in 2.6.29-rc3:
http://lkml.org/lkml/2009/1/29/150

On ARM it doesn't make sense to trace a naked function because then
mcount is called without stack and frame pointer being set up and there
is no chance to restore the lr register to the value before mcount was
called.

Reported-by: Matthias Kaehlcke <matthias@kaehlcke.net>
Tested-by: Matthias Kaehlcke <matthias@kaehlcke.net>

Cc: Abhishek Sagar <sagar.abhishek@gmail.com>
Cc: Steven Rostedt <rostedt@home.goodmis.org>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

1 files changed, 9 insertions, 1 deletions

diff --git a/include/linux/compiler-gcc.h b/include/linux/compiler-gcc.h
index 1514d534deeb..a3ed7cb8ca34 100644
--- a/include/linux/compiler-gcc.h
+++ b/include/linux/compiler-gcc.h
@@ -52,7 +52,15 @@
 #define __deprecated                    __attribute__((deprecated))
 #define __packed                        __attribute__((packed))
 #define __weak                          __attribute__((weak))
-#define __naked                         __attribute__((naked))
+
+/*
+ * it doesn't make sense on ARM (currently the only user of __naked) to trace
+ * naked functions because then mcount is called without stack and frame pointer
+ * being set up and there is no chance to restore the lr register to the value
+ * before mcount was called.
+ */
+#define __naked                         __attribute__((naked)) notrace
+
 #define __noreturn                      __attribute__((noreturn))
 
 /*