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bfff8b1b | 1 | /* Copyright (C) 2005-2017 Free Software Foundation, Inc. |
35f1e827 UD |
2 | This file is part of the GNU C Library. |
3 | Contributed by Jakub Jelinek <jakub@redhat.com>, 2005. | |
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 | |
7 | License as published by the Free Software Foundation; either | |
8 | version 2.1 of the 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 | |
59ba27a6 PE |
16 | License along with the GNU C Library; if not, see |
17 | <http://www.gnu.org/licenses/>. */ | |
35f1e827 UD |
18 | |
19 | #include <errno.h> | |
20 | #include <pthread.h> | |
21 | #include <stdbool.h> | |
ceaa9889 | 22 | #include <stddef.h> |
35f1e827 UD |
23 | #include <stdio.h> |
24 | #include <stdlib.h> | |
25 | #include <string.h> | |
26 | #include <sys/wait.h> | |
a9538892 | 27 | #include <stackguard-macros.h> |
903ae060 | 28 | #include <tls.h> |
35f1e827 UD |
29 | #include <unistd.h> |
30 | ||
31 | static const char *command; | |
32 | static bool child; | |
33 | static uintptr_t stack_chk_guard_copy; | |
34 | static bool stack_chk_guard_copy_set; | |
35 | static int fds[2]; | |
36 | ||
37 | static void __attribute__ ((constructor)) | |
38 | con (void) | |
39 | { | |
40 | stack_chk_guard_copy = STACK_CHK_GUARD; | |
41 | stack_chk_guard_copy_set = true; | |
42 | } | |
43 | ||
44 | static int | |
45 | uintptr_t_cmp (const void *a, const void *b) | |
46 | { | |
47 | if (*(uintptr_t *) a < *(uintptr_t *) b) | |
48 | return 1; | |
49 | if (*(uintptr_t *) a > *(uintptr_t *) b) | |
50 | return -1; | |
51 | return 0; | |
52 | } | |
53 | ||
54 | static void * | |
55 | tf (void *arg) | |
56 | { | |
57 | if (stack_chk_guard_copy != STACK_CHK_GUARD) | |
58 | { | |
59 | puts ("STACK_CHK_GUARD changed in thread"); | |
60 | return (void *) 1L; | |
61 | } | |
62 | return NULL; | |
63 | } | |
64 | ||
65 | static int | |
66 | do_test (void) | |
67 | { | |
68 | if (!stack_chk_guard_copy_set) | |
69 | { | |
70 | puts ("constructor has not been run"); | |
71 | return 1; | |
72 | } | |
73 | ||
74 | if (stack_chk_guard_copy != STACK_CHK_GUARD) | |
75 | { | |
76 | puts ("STACK_CHK_GUARD changed between constructor and do_test"); | |
77 | return 1; | |
78 | } | |
79 | ||
80 | if (child) | |
81 | { | |
82 | int i; | |
83 | pthread_t th[4]; | |
84 | void *ret; | |
85 | for (i = 0; i < 4; ++i) | |
86 | if (pthread_create (&th[i], NULL, tf, NULL)) | |
87 | { | |
88 | puts ("thread creation failed"); | |
89 | return 1; | |
90 | } | |
91 | for (i = 0; i < 4; ++i) | |
92 | if (pthread_join (th[i], &ret)) | |
93 | { | |
94 | puts ("thread join failed"); | |
95 | return 1; | |
96 | } | |
97 | else if (ret != NULL) | |
98 | return 1; | |
99 | ||
100 | write (2, &stack_chk_guard_copy, sizeof (stack_chk_guard_copy)); | |
101 | return 0; | |
102 | } | |
103 | ||
104 | if (command == NULL) | |
105 | { | |
106 | puts ("missing --command or --child argument"); | |
107 | return 1; | |
108 | } | |
109 | ||
110 | #define N 16 | |
111 | uintptr_t child_stack_chk_guards[N + 1]; | |
112 | child_stack_chk_guards[N] = stack_chk_guard_copy; | |
113 | int i; | |
114 | for (i = 0; i < N; ++i) | |
115 | { | |
116 | if (pipe (fds) < 0) | |
117 | { | |
118 | printf ("couldn't create pipe: %m\n"); | |
119 | return 1; | |
120 | } | |
121 | ||
122 | pid_t pid = fork (); | |
123 | if (pid < 0) | |
124 | { | |
125 | printf ("fork failed: %m\n"); | |
126 | return 1; | |
127 | } | |
128 | ||
129 | if (!pid) | |
130 | { | |
131 | if (stack_chk_guard_copy != STACK_CHK_GUARD) | |
132 | { | |
133 | puts ("STACK_CHK_GUARD changed after fork"); | |
134 | exit (1); | |
135 | } | |
136 | ||
137 | close (fds[0]); | |
138 | close (2); | |
139 | dup2 (fds[1], 2); | |
140 | close (fds[1]); | |
141 | ||
142 | system (command); | |
143 | exit (0); | |
144 | } | |
145 | ||
146 | close (fds[1]); | |
147 | ||
148 | if (TEMP_FAILURE_RETRY (read (fds[0], &child_stack_chk_guards[i], | |
149 | sizeof (uintptr_t))) != sizeof (uintptr_t)) | |
150 | { | |
151 | puts ("could not read stack_chk_guard value from child"); | |
152 | return 1; | |
153 | } | |
154 | ||
155 | close (fds[0]); | |
156 | ||
157 | pid_t termpid; | |
158 | int status; | |
159 | termpid = TEMP_FAILURE_RETRY (waitpid (pid, &status, 0)); | |
160 | if (termpid == -1) | |
161 | { | |
162 | printf ("waitpid failed: %m\n"); | |
163 | return 1; | |
164 | } | |
165 | else if (termpid != pid) | |
166 | { | |
167 | printf ("waitpid returned %ld != %ld\n", | |
168 | (long int) termpid, (long int) pid); | |
169 | return 1; | |
170 | } | |
171 | else if (!WIFEXITED (status) || WEXITSTATUS (status)) | |
172 | { | |
173 | puts ("child hasn't exited with exit status 0"); | |
174 | return 1; | |
175 | } | |
176 | } | |
177 | ||
178 | qsort (child_stack_chk_guards, N + 1, sizeof (uintptr_t), uintptr_t_cmp); | |
179 | ||
180 | uintptr_t default_guard = 0; | |
181 | unsigned char *p = (unsigned char *) &default_guard; | |
182 | p[sizeof (uintptr_t) - 1] = 255; | |
183 | p[sizeof (uintptr_t) - 2] = '\n'; | |
184 | p[0] = 0; | |
185 | ||
186 | /* Test if the stack guard canaries are either randomized, | |
187 | or equal to the default stack guard canary value. | |
188 | Even with randomized stack guards it might happen | |
189 | that the random number generator generates the same | |
190 | values, but if that happens in more than half from | |
191 | the 16 runs, something is very wrong. */ | |
192 | int ndifferences = 0; | |
193 | int ndefaults = 0; | |
c7afae94 | 194 | for (i = 0; i < N; ++i) |
35f1e827 UD |
195 | { |
196 | if (child_stack_chk_guards[i] != child_stack_chk_guards[i+1]) | |
197 | ndifferences++; | |
198 | else if (child_stack_chk_guards[i] == default_guard) | |
199 | ndefaults++; | |
200 | } | |
201 | ||
202 | printf ("differences %d defaults %d\n", ndifferences, ndefaults); | |
203 | ||
204 | if (ndifferences < N / 2 && ndefaults < N / 2) | |
205 | { | |
206 | puts ("stack guard canaries are not randomized enough"); | |
207 | puts ("nor equal to the default canary value"); | |
208 | return 1; | |
209 | } | |
210 | ||
211 | return 0; | |
212 | } | |
213 | ||
214 | #define OPT_COMMAND 10000 | |
215 | #define OPT_CHILD 10001 | |
216 | #define CMDLINE_OPTIONS \ | |
217 | { "command", required_argument, NULL, OPT_COMMAND }, \ | |
218 | { "child", no_argument, NULL, OPT_CHILD }, | |
219 | #define CMDLINE_PROCESS \ | |
220 | case OPT_COMMAND: \ | |
221 | command = optarg; \ | |
222 | break; \ | |
223 | case OPT_CHILD: \ | |
224 | child = true; \ | |
225 | break; | |
226 | #define TEST_FUNCTION do_test () | |
227 | #include "../test-skeleton.c" |