about summary refs log tree commit diff
path: root/malloc/tst-interpose-skeleton.c
blob: 853ee248d10d44d4a8f2bc754314b13a5daf0778 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
/* Test driver for malloc interposition tests.
   Copyright (C) 2016-2019 Free Software Foundation, Inc.
   This file is part of the GNU C Library.

   The GNU C Library is free software; you can redistribute it and/or
   modify it under the terms of the GNU Lesser General Public License as
   published by the Free Software Foundation; either version 2.1 of the
   License, or (at your option) any later version.

   The GNU C Library is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public
   License along with the GNU C Library; see the file COPYING.LIB.  If
   not, see <https://www.gnu.org/licenses/>.  */

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>

#if INTERPOSE_THREADS
#include <pthread.h>
#endif

static int do_test (void);
#define TEST_FUNCTION do_test ()
#include "../test-skeleton.c"

/* Fills BUFFER with a test string.  */
static void
line_string (int number, char *buffer, size_t length)
{
  for (size_t i = 0; i < length - 2; ++i)
    buffer[i] = 'A' + ((number + i) % 26);
  buffer[length - 2] = '\n';
  buffer[length - 1] = '\0';
}

/* Perform the tests.  */
static void *
run_tests (void *closure)
{
  char *temp_file_path;
  int fd = create_temp_file ("tst-malloc-interpose", &temp_file_path);
  if (fd < 0)
    _exit (1);

  /* Line lengths excluding the line terminator.  */
  static const int line_lengths[] = { 0, 45, 80, 2, 8201, 0, 17, -1 };

  /* Fill the test file with data.  */
  {
    FILE *fp = fdopen (fd, "w");
    for (int lineno = 0; line_lengths[lineno] >= 0; ++lineno)
      {
        char buffer[line_lengths[lineno] + 2];
        line_string (lineno, buffer, sizeof (buffer));
        fprintf (fp, "%s", buffer);
      }

    if (ferror (fp))
      {
        printf ("error: fprintf: %m\n");
        _exit (1);
      }
    if (fclose (fp) != 0)
      {
        printf ("error: fclose: %m\n");
        _exit (1);
      }
  }

  /* Read the test file.  This tests libc-internal allocation with
     realloc.  */
  {
    FILE *fp = fopen (temp_file_path, "r");

    char *actual = NULL;
    size_t actual_size = 0;
    for (int lineno = 0; ; ++lineno)
      {
        errno = 0;
        ssize_t result = getline (&actual, &actual_size, fp);
        if (result == 0)
          {
            printf ("error: invalid return value 0 from getline\n");
            _exit (1);
          }
        if (result < 0 && errno != 0)
          {
            printf ("error: getline: %m\n");
            _exit (1);
          }
        if (result < 0 && line_lengths[lineno] >= 0)
          {
            printf ("error: unexpected end of file after line %d\n", lineno);
            _exit (1);
          }
        if (result > 0 && line_lengths[lineno] < 0)
          {
            printf ("error: no end of file after line %d\n", lineno);
            _exit (1);
          }
        if (result == -1 && line_lengths[lineno] == -1)
          /* End of file reached as expected.  */
          break;

        if (result != line_lengths[lineno] + 1)
          {
            printf ("error: line length mismatch: expected %d, got %zd\n",
                    line_lengths[lineno], result);
            _exit (1);
          }

        char expected[line_lengths[lineno] + 2];
        line_string (lineno, expected, sizeof (expected));
        if (strcmp (actual, expected) != 0)
          {
            printf ("error: line mismatch\n");
            printf ("error:   expected: [[%s]]\n", expected);
            printf ("error:   actual:   [[%s]]\n", actual);
            _exit (1);
          }
      }

    if (fclose (fp) != 0)
      {
        printf ("error: fclose (after reading): %m\n");
        _exit (1);
      }
  }

  free (temp_file_path);

  /* Make sure that fork is working.  */
  pid_t pid = fork ();
  if (pid == -1)
    {
      printf ("error: fork: %m\n");
      _exit (1);
    }
  enum { exit_code = 55 };
  if (pid == 0)
    _exit (exit_code);
  int status;
  int ret = waitpid (pid, &status, 0);
  if (ret < 0)
    {
      printf ("error: waitpid: %m\n");
      _exit (1);
    }
  if (!WIFEXITED (status) || WEXITSTATUS (status) != exit_code)
    {
      printf ("error: unexpected exit status from child process: %d\n",
              status);
      _exit (1);
    }

  return NULL;
}

/* This is used to detect if malloc has not been successfully
   interposed.  The interposed malloc does not use brk/sbrk.  */
static void *initial_brk;
__attribute__ ((constructor))
static void
set_initial_brk (void)
{
  initial_brk = sbrk (0);
}

/* Terminate the process if the break value has been changed.  */
__attribute__ ((destructor))
static void
check_brk (void)
{
  void *current = sbrk (0);
  if (current != initial_brk)
    {
      printf ("error: brk changed from %p to %p; no interposition?\n",
              initial_brk, current);
      _exit (1);
    }
}

static int
do_test (void)
{
  check_brk ();

#if INTERPOSE_THREADS
  pthread_t thr = xpthread_create (NULL, run_tests, NULL);
  xpthread_join (thr);
#else
  run_tests (NULL);
#endif

  check_brk ();

  return 0;
}