diff options
Diffstat (limited to 'arch/arm/kernel/kprobes-common.c')
| -rw-r--r-- | arch/arm/kernel/kprobes-common.c | 33 |
1 files changed, 33 insertions, 0 deletions
diff --git a/arch/arm/kernel/kprobes-common.c b/arch/arm/kernel/kprobes-common.c index 794827ec27d7..e18576cca6cf 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; |