ARM: kprobes: Move find_str_pc_offset into kprobes-common.c
Move str_pc_offset into kprobes-common.c as it will be needed by common
code later.
Signed-off-by: Jon Medhurst <tixy@yxit.co.uk>
Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org>
diff --git a/arch/arm/kernel/kprobes-common.c b/arch/arm/kernel/kprobes-common.c
index 794827e..e18576c 100644
--- a/arch/arm/kernel/kprobes-common.c
+++ b/arch/arm/kernel/kprobes-common.c
@@ -3,6 +3,9 @@
*
* Copyright (C) 2011 Jon Medhurst <tixy@yxit.co.uk>.
*
+ * Some contents moved here from arch/arm/include/asm/kprobes-arm.c which is
+ * Copyright (C) 2006, 2007 Motorola Inc.
+ *
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
@@ -14,6 +17,36 @@
#include "kprobes.h"
+/*
+ * For STR and STM instructions, an ARM core may choose to use either
+ * a +8 or a +12 displacement from the current instruction's address.
+ * Whichever value is chosen for a given core, it must be the same for
+ * both instructions and may not change. This function measures it.
+ */
+
+int str_pc_offset;
+
+void __init find_str_pc_offset(void)
+{
+ int addr, scratch, ret;
+
+ __asm__ (
+ "sub %[ret], pc, #4 \n\t"
+ "str pc, %[addr] \n\t"
+ "ldr %[scr], %[addr] \n\t"
+ "sub %[ret], %[scr], %[ret] \n\t"
+ : [ret] "=r" (ret), [scr] "=r" (scratch), [addr] "+m" (addr));
+
+ str_pc_offset = ret;
+}
+
+
+void __init arm_kprobe_decode_init(void)
+{
+ find_str_pc_offset();
+}
+
+
static unsigned long __kprobes __check_eq(unsigned long cpsr)
{
return cpsr & PSR_Z_BIT;