[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>

arch/arm/kernel/fiq.c

@@ -88,7 +88,7 @@ void set_fiq_handler(void *start, unsigned int length)
  * disable irqs for the duration.  Note - these functions are almost
  * entirely coded in assembly.
  */
-void __attribute__((naked)) set_fiq_regs(struct pt_regs *regs)
+void __naked set_fiq_regs(struct pt_regs *regs)
 {
 	register unsigned long tmp;
 	asm volatile (
@@ -106,7 +106,7 @@ void __attribute__((naked)) set_fiq_regs(struct pt_regs *regs)
 	: "r" (&regs->ARM_r8), "I" (PSR_I_BIT | PSR_F_BIT | FIQ_MODE));
 }
 
-void __attribute__((naked)) get_fiq_regs(struct pt_regs *regs)
+void __naked get_fiq_regs(struct pt_regs *regs)
 {
 	register unsigned long tmp;
 	asm volatile (

arch/arm/mm/copypage-feroceon.c

@@ -13,7 +13,7 @@
 #include <linux/init.h>
 #include <linux/highmem.h>
 
-static void __attribute__((naked))
+static void __naked
 feroceon_copy_user_page(void *kto, const void *kfrom)
 {
 	asm("\

arch/arm/mm/copypage-v3.c

@@ -15,7 +15,7 @@
  *
  * FIXME: do we need to handle cache stuff...
  */
-static void __attribute__((naked))
+static void __naked
 v3_copy_user_page(void *kto, const void *kfrom)
 {
 	asm("\n\

arch/arm/mm/copypage-v4mc.c

@@ -44,7 +44,7 @@ static DEFINE_SPINLOCK(minicache_lock);
  * instruction.  If your processor does not supply this, you have to write your
  * own copy_user_highpage that does the right thing.
  */
-static void __attribute__((naked))
+static void __naked
 mc_copy_user_page(void *from, void *to)
 {
 	asm volatile(

arch/arm/mm/copypage-v4wb.c

@@ -22,7 +22,7 @@
  * instruction.  If your processor does not supply this, you have to write your
  * own copy_user_highpage that does the right thing.
  */
-static void __attribute__((naked))
+static void __naked
 v4wb_copy_user_page(void *kto, const void *kfrom)
 {
 	asm("\

arch/arm/mm/copypage-v4wt.c

@@ -20,7 +20,7 @@
  * dirty data in the cache.  However, we do have to ensure that
  * subsequent reads are up to date.
  */
-static void __attribute__((naked))
+static void __naked
 v4wt_copy_user_page(void *kto, const void *kfrom)
 {
 	asm("\

arch/arm/mm/copypage-xsc3.c

@@ -29,7 +29,7 @@
  * if we eventually end up using our copied page.
  *
  */
-static void __attribute__((naked))
+static void __naked
 xsc3_mc_copy_user_page(void *kto, const void *kfrom)
 {
 	asm("\

arch/arm/mm/copypage-xscale.c

@@ -42,7 +42,7 @@ static DEFINE_SPINLOCK(minicache_lock);
  * Dcache aliasing issue.  The writes will be forwarded to the write buffer,
  * and merged as appropriate.
  */
-static void __attribute__((naked))
+static void __naked
 mc_copy_user_page(void *from, void *to)
 {
 	/*

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))
 
 /*