1 /* Test driver for malloc interposition tests.
2 Copyright (C) 2016-2023 Free Software Foundation, Inc.
3 This file is part of the GNU C Library.
4
5 The GNU C Library is free software; you can redistribute it and/or
6 modify it under the terms of the GNU Lesser General Public License as
7 published by the Free Software Foundation; either version 2.1 of the
8 License, or (at your option) any later version.
9
10 The GNU C Library is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 Lesser General Public License for more details.
14
15 You should have received a copy of the GNU Lesser General Public
16 License along with the GNU C Library; see the file COPYING.LIB. If
17 not, see <https://www.gnu.org/licenses/>. */
18
19 #include <stdio.h>
20 #include <stdlib.h>
21 #include <string.h>
22 #include <unistd.h>
23
24 #if INTERPOSE_THREADS
25 #include <pthread.h>
26 #endif
27
28 static int do_test (void);
29 #define TEST_FUNCTION do_test ()
30 #include "../test-skeleton.c"
31
32 /* Fills BUFFER with a test string. */
33 static void
34 line_string (int number, char *buffer, size_t length)
35 {
36 for (size_t i = 0; i < length - 2; ++i)
37 buffer[i] = 'A' + ((number + i) % 26);
38 buffer[length - 2] = '\n';
39 buffer[length - 1] = '\0';
40 }
41
42 /* Perform the tests. */
43 static void *
44 run_tests (void *closure)
45 {
46 char *temp_file_path;
47 int fd = create_temp_file ("tst-malloc-interpose", &temp_file_path);
48 if (fd < 0)
49 _exit (1);
50
51 /* Line lengths excluding the line terminator. */
52 static const int line_lengths[] = { 0, 45, 80, 2, 8201, 0, 17, -1 };
53
54 /* Fill the test file with data. */
55 {
56 FILE *fp = fdopen (fd, "w");
57 for (int lineno = 0; line_lengths[lineno] >= 0; ++lineno)
58 {
59 char buffer[line_lengths[lineno] + 2];
60 line_string (lineno, buffer, sizeof (buffer));
61 fprintf (fp, "%s", buffer);
62 }
63
64 if (ferror (fp))
65 {
66 printf ("error: fprintf: %m\n");
67 _exit (1);
68 }
69 if (fclose (fp) != 0)
70 {
71 printf ("error: fclose: %m\n");
72 _exit (1);
73 }
74 }
75
76 /* Read the test file. This tests libc-internal allocation with
77 realloc. */
78 {
79 FILE *fp = fopen (temp_file_path, "r");
80
81 char *actual = NULL;
82 size_t actual_size = 0;
83 for (int lineno = 0; ; ++lineno)
84 {
85 errno = 0;
86 ssize_t result = getline (&actual, &actual_size, fp);
87 if (result == 0)
88 {
89 printf ("error: invalid return value 0 from getline\n");
90 _exit (1);
91 }
92 if (result < 0 && errno != 0)
93 {
94 printf ("error: getline: %m\n");
95 _exit (1);
96 }
97 if (result < 0 && line_lengths[lineno] >= 0)
98 {
99 printf ("error: unexpected end of file after line %d\n", lineno);
100 _exit (1);
101 }
102 if (result > 0 && line_lengths[lineno] < 0)
103 {
104 printf ("error: no end of file after line %d\n", lineno);
105 _exit (1);
106 }
107 if (result == -1 && line_lengths[lineno] == -1)
108 /* End of file reached as expected. */
109 break;
110
111 if (result != line_lengths[lineno] + 1)
112 {
113 printf ("error: line length mismatch: expected %d, got %zd\n",
114 line_lengths[lineno], result);
115 _exit (1);
116 }
117
118 char expected[line_lengths[lineno] + 2];
119 line_string (lineno, expected, sizeof (expected));
120 if (strcmp (actual, expected) != 0)
121 {
122 printf ("error: line mismatch\n");
123 printf ("error: expected: [[%s]]\n", expected);
124 printf ("error: actual: [[%s]]\n", actual);
125 _exit (1);
126 }
127 }
128
129 if (fclose (fp) != 0)
130 {
131 printf ("error: fclose (after reading): %m\n");
132 _exit (1);
133 }
134 }
135
136 free (temp_file_path);
137
138 /* Make sure that fork is working. */
139 pid_t pid = fork ();
140 if (pid == -1)
141 {
142 printf ("error: fork: %m\n");
143 _exit (1);
144 }
145 enum { exit_code = 55 };
146 if (pid == 0)
147 _exit (exit_code);
148 int status;
149 int ret = waitpid (pid, &status, 0);
150 if (ret < 0)
151 {
152 printf ("error: waitpid: %m\n");
153 _exit (1);
154 }
155 if (!WIFEXITED (status) || WEXITSTATUS (status) != exit_code)
156 {
157 printf ("error: unexpected exit status from child process: %d\n",
158 status);
159 _exit (1);
160 }
161
162 return NULL;
163 }
164
165 /* This is used to detect if malloc has not been successfully
166 interposed. The interposed malloc does not use brk/sbrk. */
167 static void *initial_brk;
168 __attribute__ ((constructor))
169 static void
170 set_initial_brk (void)
171 {
172 initial_brk = sbrk (0);
173 }
174
175 /* Terminate the process if the break value has been changed. */
176 __attribute__ ((destructor))
177 static void
178 check_brk (void)
179 {
180 void *current = sbrk (0);
181 if (current != initial_brk)
182 {
183 printf ("error: brk changed from %p to %p; no interposition?\n",
184 initial_brk, current);
185 _exit (1);
186 }
187 }
188
189 static int
190 do_test (void)
191 {
192 check_brk ();
193
194 #if INTERPOSE_THREADS
195 pthread_t thr = xpthread_create (NULL, run_tests, NULL);
196 xpthread_join (thr);
197 #else
198 run_tests (NULL);
199 #endif
200
201 check_brk ();
202
203 return 0;
204 }