ptrace.cpp revision 9a7fdb2dae8f0ae0f9c5b0596bb2710f782925aa 
1/*
2 * Copyright (C) 2008 The Android Open Source Project
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 *  * Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 *  * Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in
12 *    the documentation and/or other materials provided with the
13 *    distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
16 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
17 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
18 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
19 * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
20 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
21 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
22 * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
23 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
24 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
25 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26 * SUCH DAMAGE.
27 */
28
29#include <stdarg.h>
30#include <sys/ptrace.h>
31
32extern "C" long __ptrace(int req, pid_t pid, void* addr, void* data);
33
34long ptrace(int req, ...) {
35  bool is_peek = (req == PTRACE_PEEKUSR || req == PTRACE_PEEKTEXT || req == PTRACE_PEEKDATA);
36  long peek_result;
37
38  va_list args;
39  va_start(args, req);
40  pid_t pid = va_arg(args, pid_t);
41  void* addr = va_arg(args, void*);
42  void* data;
43  if (is_peek) {
44    data = &peek_result;
45  } else {
46    data = va_arg(args, void*);
47  }
48  va_end(args);
49
50  long result = __ptrace(req, pid, addr, data);
51  if (is_peek && result == 0) {
52    return peek_result;
53  }
54  return result;
55}
56