Override elf_nacl.xr linker script so that libc_pic.os links correctly
[glibc/nacl-glibc.git] / elf / tst-stackguard1.c
blob480f9297d02389cdda4d94d459ef529bb3599651
1 /* Copyright (C) 2005 Free Software Foundation, Inc.
2 This file is part of the GNU C Library.
3 Contributed by Jakub Jelinek <jakub@redhat.com>, 2005.
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.
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.
15 You should have received a copy of the GNU Lesser General Public
16 License along with the GNU C Library; if not, write to the Free
17 Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
18 02111-1307 USA. */
20 #include <errno.h>
21 #include <stdbool.h>
22 #include <stdio.h>
23 #include <stdlib.h>
24 #include <string.h>
25 #include <sys/wait.h>
26 #include <stackguard-macros.h>
27 #include <unistd.h>
29 static const char *command;
30 static bool child;
31 static uintptr_t stack_chk_guard_copy;
32 static bool stack_chk_guard_copy_set;
33 static int fds[2];
35 static void __attribute__ ((constructor))
36 con (void)
38 stack_chk_guard_copy = STACK_CHK_GUARD;
39 stack_chk_guard_copy_set = true;
42 static int
43 uintptr_t_cmp (const void *a, const void *b)
45 if (*(uintptr_t *) a < *(uintptr_t *) b)
46 return 1;
47 if (*(uintptr_t *) a > *(uintptr_t *) b)
48 return -1;
49 return 0;
52 static int
53 do_test (void)
55 if (!stack_chk_guard_copy_set)
57 puts ("constructor has not been run");
58 return 1;
61 if (stack_chk_guard_copy != STACK_CHK_GUARD)
63 puts ("STACK_CHK_GUARD changed between constructor and do_test");
64 return 1;
67 if (child)
69 write (2, &stack_chk_guard_copy, sizeof (stack_chk_guard_copy));
70 return 0;
73 if (command == NULL)
75 puts ("missing --command or --child argument");
76 return 1;
79 #define N 16
80 uintptr_t child_stack_chk_guards[N + 1];
81 child_stack_chk_guards[N] = stack_chk_guard_copy;
82 int i;
83 for (i = 0; i < N; ++i)
85 if (pipe (fds) < 0)
87 printf ("couldn't create pipe: %m\n");
88 return 1;
91 pid_t pid = fork ();
92 if (pid < 0)
94 printf ("fork failed: %m\n");
95 return 1;
98 if (!pid)
100 if (stack_chk_guard_copy != STACK_CHK_GUARD)
102 puts ("STACK_CHK_GUARD changed after fork");
103 exit (1);
106 close (fds[0]);
107 close (2);
108 dup2 (fds[1], 2);
109 close (fds[1]);
111 system (command);
112 exit (0);
115 close (fds[1]);
117 if (TEMP_FAILURE_RETRY (read (fds[0], &child_stack_chk_guards[i],
118 sizeof (uintptr_t))) != sizeof (uintptr_t))
120 puts ("could not read stack_chk_guard value from child");
121 return 1;
124 close (fds[0]);
126 pid_t termpid;
127 int status;
128 termpid = TEMP_FAILURE_RETRY (waitpid (pid, &status, 0));
129 if (termpid == -1)
131 printf ("waitpid failed: %m\n");
132 return 1;
134 else if (termpid != pid)
136 printf ("waitpid returned %ld != %ld\n",
137 (long int) termpid, (long int) pid);
138 return 1;
140 else if (!WIFEXITED (status) || WEXITSTATUS (status))
142 puts ("child hasn't exited with exit status 0");
143 return 1;
147 qsort (child_stack_chk_guards, N + 1, sizeof (uintptr_t), uintptr_t_cmp);
149 uintptr_t default_guard = 0;
150 unsigned char *p = (unsigned char *) &default_guard;
151 p[sizeof (uintptr_t) - 1] = 255;
152 p[sizeof (uintptr_t) - 2] = '\n';
153 p[0] = 0;
155 /* Test if the stack guard canaries are either randomized,
156 or equal to the default stack guard canary value.
157 Even with randomized stack guards it might happen
158 that the random number generator generates the same
159 values, but if that happens in more than half from
160 the 16 runs, something is very wrong. */
161 int ndifferences = 0;
162 int ndefaults = 0;
163 for (i = 0; i < N; ++i)
165 if (child_stack_chk_guards[i] != child_stack_chk_guards[i+1])
166 ndifferences++;
167 else if (child_stack_chk_guards[i] == default_guard)
168 ndefaults++;
171 printf ("differences %d defaults %d\n", ndifferences, ndefaults);
173 if (ndifferences < N / 2 && ndefaults < N / 2)
175 puts ("stack guard canaries are not randomized enough");
176 puts ("nor equal to the default canary value");
177 return 1;
180 return 0;
183 #define OPT_COMMAND 10000
184 #define OPT_CHILD 10001
185 #define CMDLINE_OPTIONS \
186 { "command", required_argument, NULL, OPT_COMMAND }, \
187 { "child", no_argument, NULL, OPT_CHILD },
188 #define CMDLINE_PROCESS \
189 case OPT_COMMAND: \
190 command = optarg; \
191 break; \
192 case OPT_CHILD: \
193 child = true; \
194 break;
195 #define TEST_FUNCTION do_test ()
196 #include "../test-skeleton.c"