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authorJon Medhurst <tixy@yxit.co.uk>2011-07-07 05:21:40 -0400
committerTixy <tixy@medhuaa1.miniserver.com>2011-07-13 13:32:41 -0400
commit6c8df3300f60cae54aeb2a6dda8efe7ffe16a322 (patch)
treec7cac1abd0d5a46db1a4b4b3785238874822218b
parent1b59d874660be7f790861ad849858cc009089515 (diff)
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>
-rw-r--r--arch/arm/kernel/kprobes-arm.c28
-rw-r--r--arch/arm/kernel/kprobes-common.c33
-rw-r--r--arch/arm/kernel/kprobes.h2
3 files changed, 35 insertions, 28 deletions
diff --git a/arch/arm/kernel/kprobes-arm.c b/arch/arm/kernel/kprobes-arm.c
index 3c4678edcbf..0262b29163d 100644
--- a/arch/arm/kernel/kprobes-arm.c
+++ b/arch/arm/kernel/kprobes-arm.c
@@ -92,29 +92,6 @@ union reg_pair {
92}; 92};
93 93
94/* 94/*
95 * For STR and STM instructions, an ARM core may choose to use either
96 * a +8 or a +12 displacement from the current instruction's address.
97 * Whichever value is chosen for a given core, it must be the same for
98 * both instructions and may not change. This function measures it.
99 */
100
101static int str_pc_offset;
102
103static void __init find_str_pc_offset(void)
104{
105 int addr, scratch, ret;
106
107 __asm__ (
108 "sub %[ret], pc, #4 \n\t"
109 "str pc, %[addr] \n\t"
110 "ldr %[scr], %[addr] \n\t"
111 "sub %[ret], %[scr], %[ret] \n\t"
112 : [ret] "=r" (ret), [scr] "=r" (scratch), [addr] "+m" (addr));
113
114 str_pc_offset = ret;
115}
116
117/*
118 * The insnslot_?arg_r[w]flags() functions below are to keep the 95 * The insnslot_?arg_r[w]flags() functions below are to keep the
119 * msr -> *fn -> mrs instruction sequences indivisible so that 96 * msr -> *fn -> mrs instruction sequences indivisible so that
120 * the state of the CPSR flags aren't inadvertently modified 97 * the state of the CPSR flags aren't inadvertently modified
@@ -1569,8 +1546,3 @@ arm_kprobe_decode_insn(kprobe_opcode_t insn, struct arch_specific_insn *asi)
1569 1546
1570 return space_cccc_11xx(insn, asi); 1547 return space_cccc_11xx(insn, asi);
1571} 1548}
1572
1573void __init arm_kprobe_decode_init(void)
1574{
1575 find_str_pc_offset();
1576}
diff --git a/arch/arm/kernel/kprobes-common.c b/arch/arm/kernel/kprobes-common.c
index 794827ec27d..e18576cca6c 100644
--- a/arch/arm/kernel/kprobes-common.c
+++ b/arch/arm/kernel/kprobes-common.c
@@ -3,6 +3,9 @@
3 * 3 *
4 * Copyright (C) 2011 Jon Medhurst <tixy@yxit.co.uk>. 4 * Copyright (C) 2011 Jon Medhurst <tixy@yxit.co.uk>.
5 * 5 *
6 * Some contents moved here from arch/arm/include/asm/kprobes-arm.c which is
7 * Copyright (C) 2006, 2007 Motorola Inc.
8 *
6 * This program is free software; you can redistribute it and/or modify 9 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License version 2 as 10 * it under the terms of the GNU General Public License version 2 as
8 * published by the Free Software Foundation. 11 * published by the Free Software Foundation.
@@ -14,6 +17,36 @@
14#include "kprobes.h" 17#include "kprobes.h"
15 18
16 19
20/*
21 * For STR and STM instructions, an ARM core may choose to use either
22 * a +8 or a +12 displacement from the current instruction's address.
23 * Whichever value is chosen for a given core, it must be the same for
24 * both instructions and may not change. This function measures it.
25 */
26
27int str_pc_offset;
28
29void __init find_str_pc_offset(void)
30{
31 int addr, scratch, ret;
32
33 __asm__ (
34 "sub %[ret], pc, #4 \n\t"
35 "str pc, %[addr] \n\t"
36 "ldr %[scr], %[addr] \n\t"
37 "sub %[ret], %[scr], %[ret] \n\t"
38 : [ret] "=r" (ret), [scr] "=r" (scratch), [addr] "+m" (addr));
39
40 str_pc_offset = ret;
41}
42
43
44void __init arm_kprobe_decode_init(void)
45{
46 find_str_pc_offset();
47}
48
49
17static unsigned long __kprobes __check_eq(unsigned long cpsr) 50static unsigned long __kprobes __check_eq(unsigned long cpsr)
18{ 51{
19 return cpsr & PSR_Z_BIT; 52 return cpsr & PSR_Z_BIT;
diff --git a/arch/arm/kernel/kprobes.h b/arch/arm/kernel/kprobes.h
index 4de2f37b1a8..43f630d7f03 100644
--- a/arch/arm/kernel/kprobes.h
+++ b/arch/arm/kernel/kprobes.h
@@ -36,6 +36,8 @@ void __init arm_kprobe_decode_init(void);
36 36
37extern kprobe_check_cc * const kprobe_condition_checks[16]; 37extern kprobe_check_cc * const kprobe_condition_checks[16];
38 38
39extern int str_pc_offset;
40
39/* 41/*
40 * Test if load/store instructions writeback the address register. 42 * Test if load/store instructions writeback the address register.
41 * if P (bit 24) == 0 or W (bit 21) == 1 43 * if P (bit 24) == 0 or W (bit 21) == 1