1 /*
2 * This file is part of ltrace.
3 * Copyright (C) 2011 Petr Machata, Red Hat Inc.
4 * Copyright (C) 2006 Ian Wienand
5 * Copyright (C) 2002,2008,2009 Juan Cespedes
6 *
7 * This program is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU General Public License as
9 * published by the Free Software Foundation; either version 2 of the
10 * License, or (at your option) any later version.
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
23 #include "config.h"
24
25 #include <sys/ptrace.h>
26 #include <errno.h>
27 #include <string.h>
28 #include <stdio.h>
29
30 #include "common.h"
31 #include "backend.h"
32 #include "sysdep.h"
33 #include "breakpoint.h"
34 #include "proc.h"
35 #include "library.h"
36
37 #ifdef ARCH_HAVE_ENABLE_BREAKPOINT
38 extern void arch_enable_breakpoint(pid_t, struct breakpoint *);
39 #else /* ARCH_HAVE_ENABLE_BREAKPOINT */
40 void
arch_enable_breakpoint(pid_t pid,struct breakpoint * sbp)41 arch_enable_breakpoint(pid_t pid, struct breakpoint *sbp)
42 {
43 static unsigned char break_insn[] = BREAKPOINT_VALUE;
44 unsigned int i, j;
45
46 debug(DEBUG_PROCESS,
47 "arch_enable_breakpoint: pid=%d, addr=%p, symbol=%s",
48 pid, sbp->addr, breakpoint_name(sbp));
49
50 for (i = 0; i < 1 + ((BREAKPOINT_LENGTH - 1) / sizeof(long)); i++) {
51 long a = ptrace(PTRACE_PEEKTEXT, pid,
52 sbp->addr + i * sizeof(long), 0);
53 if (a == -1 && errno) {
54 fprintf(stderr, "enable_breakpoint"
55 " pid=%d, addr=%p, symbol=%s: %s\n",
56 pid, sbp->addr, breakpoint_name(sbp),
57 strerror(errno));
58 return;
59 }
60 for (j = 0;
61 j < sizeof(long)
62 && i * sizeof(long) + j < BREAKPOINT_LENGTH; j++) {
63 unsigned char *bytes = (unsigned char *)&a;
64
65 sbp->orig_value[i * sizeof(long) + j] = bytes[j];
66 bytes[j] = break_insn[i * sizeof(long) + j];
67 }
68 a = ptrace(PTRACE_POKETEXT, pid,
69 sbp->addr + i * sizeof(long), a);
70 if (a == -1) {
71 fprintf(stderr, "enable_breakpoint"
72 " pid=%d, addr=%p, symbol=%s: %s\n",
73 pid, sbp->addr, breakpoint_name(sbp),
74 strerror(errno));
75 return;
76 }
77 }
78 }
79 #endif /* ARCH_HAVE_ENABLE_BREAKPOINT */
80
81 void
enable_breakpoint(struct process * proc,struct breakpoint * sbp)82 enable_breakpoint(struct process *proc, struct breakpoint *sbp)
83 {
84 debug(DEBUG_PROCESS, "enable_breakpoint: pid=%d, addr=%p, symbol=%s",
85 proc->pid, sbp->addr, breakpoint_name(sbp));
86 arch_enable_breakpoint(proc->pid, sbp);
87 }
88
89 #ifdef ARCH_HAVE_DISABLE_BREAKPOINT
90 extern void arch_disable_breakpoint(pid_t, const struct breakpoint *sbp);
91 #else /* ARCH_HAVE_DISABLE_BREAKPOINT */
92 void
arch_disable_breakpoint(pid_t pid,const struct breakpoint * sbp)93 arch_disable_breakpoint(pid_t pid, const struct breakpoint *sbp)
94 {
95 unsigned int i, j;
96
97 debug(DEBUG_PROCESS,
98 "arch_disable_breakpoint: pid=%d, addr=%p, symbol=%s",
99 pid, sbp->addr, breakpoint_name(sbp));
100
101 for (i = 0; i < 1 + ((BREAKPOINT_LENGTH - 1) / sizeof(long)); i++) {
102 long a = ptrace(PTRACE_PEEKTEXT, pid,
103 sbp->addr + i * sizeof(long), 0);
104 if (a == -1 && errno) {
105 fprintf(stderr,
106 "disable_breakpoint pid=%d, addr=%p: %s\n",
107 pid, sbp->addr, strerror(errno));
108 return;
109 }
110 for (j = 0;
111 j < sizeof(long)
112 && i * sizeof(long) + j < BREAKPOINT_LENGTH; j++) {
113 unsigned char *bytes = (unsigned char *)&a;
114
115 bytes[j] = sbp->orig_value[i * sizeof(long) + j];
116 }
117 a = ptrace(PTRACE_POKETEXT, pid,
118 sbp->addr + i * sizeof(long), a);
119 if (a == -1 && errno) {
120 fprintf(stderr,
121 "disable_breakpoint pid=%d, addr=%p: %s\n",
122 pid, sbp->addr, strerror(errno));
123 return;
124 }
125 }
126 }
127 #endif /* ARCH_HAVE_DISABLE_BREAKPOINT */
128
129 void
disable_breakpoint(struct process * proc,struct breakpoint * sbp)130 disable_breakpoint(struct process *proc, struct breakpoint *sbp)
131 {
132 debug(DEBUG_PROCESS, "disable_breakpoint: pid=%d, addr=%p, symbol=%s",
133 proc->pid, sbp->addr, breakpoint_name(sbp));
134 arch_disable_breakpoint(proc->pid, sbp);
135 }
136