sysdeps/linux-gnu/arm/breakpoint.c

   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 "config.h"
  27 #include "arch.h"
  28 #include "options.h"
  29 #include "output.h"
  30 #include "debug.h"
  31
  32 void
  33 arch_enable_breakpoint(pid_t pid, Breakpoint *sbp) {
  34         unsigned int i, j;
  35         const unsigned char break_insn[] = BREAKPOINT_VALUE;
  36         const unsigned char thumb_break_insn[] = THUMB_BREAKPOINT_VALUE;
  37
  38         debug(1, "arch_enable_breakpoint(%d,%p)", pid, sbp->addr);
  39
  40         for (i = 0; i < 1 + ((BREAKPOINT_LENGTH - 1) / sizeof(long)); i++) {
  41                 long a = ptrace(PTRACE_PEEKTEXT, pid, sbp->addr + i * sizeof(long), 0);
  42                 unsigned char *bytes = (unsigned char *)&a;
  43
  44                 debug(2, "current = 0x%lx, orig_value = 0x%lx, thumb_mode = %d", a, *(long *)&sbp->orig_value, sbp->thumb_mode);
  45                 for (j = 0; j < sizeof(long) && i * sizeof(long) + j < BREAKPOINT_LENGTH; j++) {
  46
  47                         sbp->orig_value[i * sizeof(long) + j] = bytes[j];
  48                         if (!sbp->thumb_mode) {
  49                                 bytes[j] = break_insn[i * sizeof(long) + j];
  50                         }
  51                         else if (j < THUMB_BREAKPOINT_LENGTH) {
  52                                 bytes[j] = thumb_break_insn[i * sizeof(long) + j];
  53                         }
  54                 }
  55                 ptrace(PTRACE_POKETEXT, pid, sbp->addr + i * sizeof(long), a);
  56         }
  57 }
  58
  59 void
  60 arch_disable_breakpoint(pid_t pid, const Breakpoint *sbp) {
  61         unsigned int i, j;
  62         const unsigned char break_insn[] = BREAKPOINT_VALUE;
  63         const unsigned char thumb_break_insn[] = THUMB_BREAKPOINT_VALUE;
  64
  65         debug(1, "arch_disable_breakpoint(%d,%p)", pid, sbp->addr);
  66
  67         for (i = 0; i < 1 + ((BREAKPOINT_LENGTH - 1) / sizeof(long)); i++) {
  68                 long a = ptrace(PTRACE_PEEKTEXT, pid, sbp->addr + i * sizeof(long), 0);
  69                 unsigned char *bytes = (unsigned char *)&a;
  70
  71                 debug(2, "current = 0x%lx, orig_value = 0x%lx, thumb_mode = %d", a, *(long *)&sbp->orig_value, sbp->thumb_mode);
  72                 for (j = 0; j < sizeof(long) && i * sizeof(long) + j < BREAKPOINT_LENGTH; j++) {
  73                         bytes[j] = sbp->orig_value[i * sizeof(long) + j];
  74                 }
  75                 ptrace(PTRACE_POKETEXT, pid, sbp->addr + i * sizeof(long), a);
  76         }
  77 }