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
33 void
arch_enable_breakpoint(pid_t pid,struct breakpoint * sbp)34 arch_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
68 void
arch_disable_breakpoint(pid_t pid,const struct breakpoint * sbp)69 arch_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
94 int
arch_breakpoint_init(struct process * proc,struct breakpoint * sbp)95 arch_breakpoint_init(struct process *proc, struct breakpoint *sbp)
96 {
97 /* XXX double cast */
98 sbp->arch.thumb_mode = ((uintptr_t)sbp->addr) & 1;
99 if (sbp->arch.thumb_mode)
100 /* XXX double cast */
101 sbp->addr = (arch_addr_t)((uintptr_t)sbp->addr & ~1);
102 return 0;
103 }
104
105 void
arch_breakpoint_destroy(struct breakpoint * sbp)106 arch_breakpoint_destroy(struct breakpoint *sbp)
107 {
108 }
109
110 int
arch_breakpoint_clone(struct breakpoint * retp,struct breakpoint * sbp)111 arch_breakpoint_clone(struct breakpoint *retp, struct breakpoint *sbp)
112 {
113 retp->arch.thumb_mode = sbp->arch.thumb_mode;
114 return 0;
115 }
116