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6d7e8eda | 1 | /* Copyright (C) 2013-2023 Free Software Foundation, Inc. |
c61b4d41 CD |
2 | This file is part of the GNU C Library. |
3 | ||
4 | The GNU C Library is free software; you can redistribute it and/or | |
5 | modify it under the terms of the GNU Lesser General Public | |
6 | License as published by the Free Software Foundation; either | |
7 | version 2.1 of the License, or (at your option) any later version. | |
8 | ||
9 | The GNU C Library is distributed in the hope that it will be useful, | |
10 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
11 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
12 | Lesser General Public License for more details. | |
13 | ||
14 | You should have received a copy of the GNU Lesser General Public | |
15 | License along with the GNU C Library; if not, see | |
5a82c748 | 16 | <https://www.gnu.org/licenses/>. */ |
c61b4d41 CD |
17 | |
18 | #include <errno.h> | |
19 | #include <stdbool.h> | |
20 | #include <stdio.h> | |
21 | #include <stdlib.h> | |
22 | #include <string.h> | |
23 | #include <sys/wait.h> | |
24 | #include <stackguard-macros.h> | |
25 | #include <tls.h> | |
26 | #include <unistd.h> | |
27 | ||
36fe25fd WSM |
28 | #ifndef _GNU_SOURCE |
29 | #define _GNU_SOURCE | |
30 | #endif | |
31 | /* Requires _GNU_SOURCE */ | |
32 | #include <getopt.h> | |
33 | ||
c61b4d41 CD |
34 | #ifndef POINTER_CHK_GUARD |
35 | extern uintptr_t __pointer_chk_guard; | |
36 | # define POINTER_CHK_GUARD __pointer_chk_guard | |
37 | #endif | |
38 | ||
39 | static const char *command; | |
40 | static bool child; | |
41 | static uintptr_t ptr_chk_guard_copy; | |
42 | static bool ptr_chk_guard_copy_set; | |
43 | static int fds[2]; | |
44 | ||
45 | static void __attribute__ ((constructor)) | |
46 | con (void) | |
47 | { | |
48 | ptr_chk_guard_copy = POINTER_CHK_GUARD; | |
49 | ptr_chk_guard_copy_set = true; | |
50 | } | |
51 | ||
52 | static int | |
53 | uintptr_t_cmp (const void *a, const void *b) | |
54 | { | |
55 | if (*(uintptr_t *) a < *(uintptr_t *) b) | |
56 | return 1; | |
57 | if (*(uintptr_t *) a > *(uintptr_t *) b) | |
58 | return -1; | |
59 | return 0; | |
60 | } | |
61 | ||
62 | static int | |
63 | do_test (void) | |
64 | { | |
65 | if (!ptr_chk_guard_copy_set) | |
66 | { | |
67 | puts ("constructor has not been run"); | |
68 | return 1; | |
69 | } | |
70 | ||
71 | if (ptr_chk_guard_copy != POINTER_CHK_GUARD) | |
72 | { | |
73 | puts ("POINTER_CHK_GUARD changed between constructor and do_test"); | |
74 | return 1; | |
75 | } | |
76 | ||
77 | if (child) | |
78 | { | |
79 | write (2, &ptr_chk_guard_copy, sizeof (ptr_chk_guard_copy)); | |
80 | return 0; | |
81 | } | |
82 | ||
83 | if (command == NULL) | |
84 | { | |
85 | puts ("missing --command or --child argument"); | |
86 | return 1; | |
87 | } | |
88 | ||
89 | #define N 16 | |
90 | uintptr_t child_ptr_chk_guards[N + 1]; | |
91 | child_ptr_chk_guards[N] = ptr_chk_guard_copy; | |
92 | int i; | |
93 | for (i = 0; i < N; ++i) | |
94 | { | |
95 | if (pipe (fds) < 0) | |
96 | { | |
97 | printf ("couldn't create pipe: %m\n"); | |
98 | return 1; | |
99 | } | |
100 | ||
101 | pid_t pid = fork (); | |
102 | if (pid < 0) | |
103 | { | |
104 | printf ("fork failed: %m\n"); | |
105 | return 1; | |
106 | } | |
107 | ||
108 | if (!pid) | |
109 | { | |
110 | if (ptr_chk_guard_copy != POINTER_CHK_GUARD) | |
111 | { | |
112 | puts ("POINTER_CHK_GUARD changed after fork"); | |
113 | exit (1); | |
114 | } | |
115 | ||
116 | close (fds[0]); | |
117 | close (2); | |
118 | dup2 (fds[1], 2); | |
119 | close (fds[1]); | |
120 | ||
121 | system (command); | |
122 | exit (0); | |
123 | } | |
124 | ||
125 | close (fds[1]); | |
126 | ||
127 | if (TEMP_FAILURE_RETRY (read (fds[0], &child_ptr_chk_guards[i], | |
128 | sizeof (uintptr_t))) != sizeof (uintptr_t)) | |
129 | { | |
130 | puts ("could not read ptr_chk_guard value from child"); | |
131 | return 1; | |
132 | } | |
133 | ||
134 | close (fds[0]); | |
135 | ||
136 | pid_t termpid; | |
137 | int status; | |
138 | termpid = TEMP_FAILURE_RETRY (waitpid (pid, &status, 0)); | |
139 | if (termpid == -1) | |
140 | { | |
141 | printf ("waitpid failed: %m\n"); | |
142 | return 1; | |
143 | } | |
144 | else if (termpid != pid) | |
145 | { | |
146 | printf ("waitpid returned %ld != %ld\n", | |
147 | (long int) termpid, (long int) pid); | |
148 | return 1; | |
149 | } | |
150 | else if (!WIFEXITED (status) || WEXITSTATUS (status)) | |
151 | { | |
152 | puts ("child hasn't exited with exit status 0"); | |
153 | return 1; | |
154 | } | |
155 | } | |
156 | ||
157 | qsort (child_ptr_chk_guards, N + 1, sizeof (uintptr_t), uintptr_t_cmp); | |
158 | ||
159 | /* The default pointer guard is the same as the default stack guard. | |
160 | They are only set to default if dl_random is NULL. */ | |
161 | uintptr_t default_guard = 0; | |
162 | unsigned char *p = (unsigned char *) &default_guard; | |
163 | p[sizeof (uintptr_t) - 1] = 255; | |
164 | p[sizeof (uintptr_t) - 2] = '\n'; | |
165 | p[0] = 0; | |
166 | ||
167 | /* Test if the pointer guard canaries are either randomized, | |
168 | or equal to the default pointer guard value. | |
169 | Even with randomized pointer guards it might happen | |
170 | that the random number generator generates the same | |
171 | values, but if that happens in more than half from | |
172 | the 16 runs, something is very wrong. */ | |
173 | int ndifferences = 0; | |
174 | int ndefaults = 0; | |
175 | for (i = 0; i < N; ++i) | |
176 | { | |
177 | if (child_ptr_chk_guards[i] != child_ptr_chk_guards[i+1]) | |
178 | ndifferences++; | |
179 | else if (child_ptr_chk_guards[i] == default_guard) | |
180 | ndefaults++; | |
181 | } | |
182 | ||
183 | printf ("differences %d defaults %d\n", ndifferences, ndefaults); | |
184 | ||
185 | if (ndifferences < N / 2 && ndefaults < N / 2) | |
186 | { | |
187 | puts ("pointer guard values are not randomized enough"); | |
188 | puts ("nor equal to the default value"); | |
189 | return 1; | |
190 | } | |
191 | ||
192 | return 0; | |
193 | } | |
194 | ||
195 | #define OPT_COMMAND 10000 | |
196 | #define OPT_CHILD 10001 | |
197 | #define CMDLINE_OPTIONS \ | |
198 | { "command", required_argument, NULL, OPT_COMMAND }, \ | |
199 | { "child", no_argument, NULL, OPT_CHILD }, | |
36fe25fd WSM |
200 | |
201 | static void __attribute((used)) | |
202 | cmdline_process_function (int c) | |
203 | { | |
204 | switch (c) | |
205 | { | |
206 | case OPT_COMMAND: | |
207 | command = optarg; | |
208 | break; | |
209 | case OPT_CHILD: | |
210 | child = true; | |
211 | break; | |
212 | } | |
213 | } | |
214 | ||
215 | #define CMDLINE_PROCESS cmdline_process_function | |
216 | ||
217 | #include <support/test-driver.c> |