breakpoint.c revision c897cb796dc4a7d256cbfbf0137ef7cdff9e8ece
1/* 2 * This file is part of ltrace. 3 * 4 * Copyright (C) 2007 by Instituto Nokia de Tecnologia (INdT) 5 * 6 * Author: Anderson Lizardo <anderson.lizardo@indt.org.br> 7 * 8 * This program is free software; you can redistribute it and/or 9 * modify it under the terms of the GNU General Public License 10 * version 2 as published by the Free Software Foundation. 11 * 12 * This program is distributed in the hope that it will be useful, but 13 * WITHOUT ANY WARRANTY; without even the implied warranty of 14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 15 * General Public License for more details. 16 * 17 * You should have received a copy of the GNU General Public License 18 * along with this program; if not, write to the Free Software 19 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 20 * 02110-1301 USA 21 * 22 * Modified from sysdeps/linux-gnu/breakpoint.c and added ARM Thumb support. 23 */ 24 25#include <sys/ptrace.h> 26#include <sys/types.h> 27 28#include "config.h" 29#include "breakpoint.h" 30#include "debug.h" 31#include "proc.h" 32 33void 34arch_enable_breakpoint(pid_t pid, struct breakpoint *sbp) 35{ 36 unsigned int i, j; 37 const unsigned char break_insn[] = BREAKPOINT_VALUE; 38 const unsigned char thumb_break_insn[] = THUMB_BREAKPOINT_VALUE; 39 40 debug(1, "arch_enable_breakpoint(%d,%p)", pid, sbp->addr); 41 42 for (i = 0; i < 1 + ((BREAKPOINT_LENGTH - 1) / sizeof(long)); i++) { 43 union _ { long l; unsigned char b[SIZEOF_LONG]; }; 44 union _ orig, current; 45 unsigned char *bytes = current.b; 46 for (j = 0; j < sizeof(long); j++) { 47 orig.b[j] = sbp->orig_value[i * sizeof(long) + j]; 48 } 49 current.l = ptrace(PTRACE_PEEKTEXT, pid, sbp->addr + i * sizeof(long), 0); 50 51 debug(2, "current = 0x%lx, orig_value = 0x%lx, thumb_mode = %d", 52 current.l, orig.l, sbp->arch.thumb_mode); 53 for (j = 0; j < sizeof(long) && i * sizeof(long) + j < BREAKPOINT_LENGTH; j++) { 54 55 sbp->orig_value[i * sizeof(long) + j] = bytes[j]; 56 if (!sbp->arch.thumb_mode) { 57 bytes[j] = break_insn[i * sizeof(long) + j]; 58 } 59 else if (j < THUMB_BREAKPOINT_LENGTH) { 60 bytes[j] = thumb_break_insn[i * sizeof(long) + j]; 61 } 62 } 63 ptrace(PTRACE_POKETEXT, pid, sbp->addr + i * sizeof(long), 64 (void *)current.l); 65 } 66} 67 68void 69arch_disable_breakpoint(pid_t pid, const struct breakpoint *sbp) 70{ 71 unsigned int i, j; 72 73 debug(1, "arch_disable_breakpoint(%d,%p)", pid, sbp->addr); 74 75 for (i = 0; i < 1 + ((BREAKPOINT_LENGTH - 1) / sizeof(long)); i++) { 76 union _ { long l; unsigned char b[SIZEOF_LONG]; }; 77 union _ orig, current; 78 unsigned char *bytes = current.b; 79 for (j = 0; j < sizeof(long); j++) { 80 orig.b[j] = sbp->orig_value[i * sizeof(long) + j]; 81 } 82 current.l = ptrace(PTRACE_PEEKTEXT, pid, sbp->addr + i * sizeof(long), 0); 83 84 debug(2, "current = 0x%lx, orig_value = 0x%lx, thumb_mode = %d", 85 current.l, orig.l, sbp->arch.thumb_mode); 86 for (j = 0; j < sizeof(long) && i * sizeof(long) + j < BREAKPOINT_LENGTH; j++) { 87 bytes[j] = sbp->orig_value[i * sizeof(long) + j]; 88 } 89 ptrace(PTRACE_POKETEXT, pid, sbp->addr + i * sizeof(long), 90 (void *)current.l); 91 } 92} 93 94int 95arch_breakpoint_init(struct Process *proc, struct breakpoint *sbp) 96{ 97 /* XXX That uintptr_t cast is there temporarily until 98 * target_address_t becomes integral type. */ 99 int thumb_mode = ((uintptr_t)sbp->addr) & 1; 100 if (thumb_mode) 101 sbp->addr = (void *)((uintptr_t)sbp->addr & ~1); 102 sbp->arch.thumb_mode = thumb_mode | proc->thumb_mode; 103 /* XXX This doesn't seem like it belongs here. */ 104 proc->thumb_mode = 0; 105 return 0; 106} 107 108void 109arch_breakpoint_destroy(struct breakpoint *sbp) 110{ 111} 112 113int 114arch_breakpoint_clone(struct breakpoint *retp, struct breakpoint *sbp) 115{ 116 retp->arch.thumb_mode = sbp->arch.thumb_mode; 117 return 0; 118} 119