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authorJakub Jelinek <jakub@redhat.com>2007-07-12 18:26:36 +0000
committerJakub Jelinek <jakub@redhat.com>2007-07-12 18:26:36 +0000
commit0ecb606cb6cf65de1d9fc8a919bceb4be476c602 (patch)
tree2ea1f8305970753e4a657acb2ccc15ca3eec8e2c /elf/tst-stackguard1.c
parent7d58530341304d403a6626d7f7a1913165fe2f32 (diff)
downloadglibc-0ecb606cb6cf65de1d9fc8a919bceb4be476c602.tar.gz
2.5-18.1
Diffstat (limited to 'elf/tst-stackguard1.c')
-rw-r--r--elf/tst-stackguard1.c200
1 files changed, 200 insertions, 0 deletions
diff --git a/elf/tst-stackguard1.c b/elf/tst-stackguard1.c
new file mode 100644
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+++ b/elf/tst-stackguard1.c
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+/* Copyright (C) 2005 Free Software Foundation, Inc.
+ This file is part of the GNU C Library.
+ Contributed by Jakub Jelinek <jakub@redhat.com>, 2005.
+
+ 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; if not, write to the Free
+ Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+ 02111-1307 USA. */
+
+#include <errno.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/wait.h>
+#include <stackguard-macros.h>
+#include <unistd.h>
+
+static const char *command;
+static bool child;
+static uintptr_t stack_chk_guard_copy;
+static bool stack_chk_guard_copy_set;
+static int fds[2];
+
+static void __attribute__ ((constructor))
+con (void)
+{
+ stack_chk_guard_copy = STACK_CHK_GUARD;
+ stack_chk_guard_copy_set = true;
+}
+
+static int
+uintptr_t_cmp (const void *a, const void *b)
+{
+ if (*(uintptr_t *) a < *(uintptr_t *) b)
+ return 1;
+ if (*(uintptr_t *) a > *(uintptr_t *) b)
+ return -1;
+ return 0;
+}
+
+static int
+do_test (void)
+{
+ if (!stack_chk_guard_copy_set)
+ {
+ puts ("constructor has not been run");
+ return 1;
+ }
+
+ if (stack_chk_guard_copy != STACK_CHK_GUARD)
+ {
+ puts ("STACK_CHK_GUARD changed between constructor and do_test");
+ return 1;
+ }
+
+ if (child)
+ {
+ write (2, &stack_chk_guard_copy, sizeof (stack_chk_guard_copy));
+ return 0;
+ }
+
+ if (command == NULL)
+ {
+ puts ("missing --command or --child argument");
+ return 1;
+ }
+
+#define N 16
+ uintptr_t child_stack_chk_guards[N + 1];
+ child_stack_chk_guards[N] = stack_chk_guard_copy;
+ int i;
+ for (i = 0; i < N; ++i)
+ {
+ if (pipe (fds) < 0)
+ {
+ printf ("couldn't create pipe: %m\n");
+ return 1;
+ }
+
+ pid_t pid = fork ();
+ if (pid < 0)
+ {
+ printf ("fork failed: %m\n");
+ return 1;
+ }
+
+ if (!pid)
+ {
+ if (stack_chk_guard_copy != STACK_CHK_GUARD)
+ {
+ puts ("STACK_CHK_GUARD changed after fork");
+ exit (1);
+ }
+
+ close (fds[0]);
+ close (2);
+ dup2 (fds[1], 2);
+ close (fds[1]);
+
+ system (command);
+ exit (0);
+ }
+
+ close (fds[1]);
+
+ if (TEMP_FAILURE_RETRY (read (fds[0], &child_stack_chk_guards[i],
+ sizeof (uintptr_t))) != sizeof (uintptr_t))
+ {
+ puts ("could not read stack_chk_guard value from child");
+ return 1;
+ }
+
+ close (fds[0]);
+
+ pid_t termpid;
+ int status;
+ termpid = TEMP_FAILURE_RETRY (waitpid (pid, &status, 0));
+ if (termpid == -1)
+ {
+ printf ("waitpid failed: %m\n");
+ return 1;
+ }
+ else if (termpid != pid)
+ {
+ printf ("waitpid returned %ld != %ld\n",
+ (long int) termpid, (long int) pid);
+ return 1;
+ }
+ else if (!WIFEXITED (status) || WEXITSTATUS (status))
+ {
+ puts ("child hasn't exited with exit status 0");
+ return 1;
+ }
+ }
+
+ qsort (child_stack_chk_guards, N + 1, sizeof (uintptr_t), uintptr_t_cmp);
+
+ uintptr_t default_guard = 0;
+ unsigned char *p = (unsigned char *) &default_guard;
+ p[sizeof (uintptr_t) - 1] = 255;
+ p[sizeof (uintptr_t) - 2] = '\n';
+ p[0] = 0;
+
+ /* Test if the stack guard canaries are either randomized,
+ or equal to the default stack guard canary value.
+ Even with randomized stack guards it might happen
+ that the random number generator generates the same
+ values, but if that happens in more than half from
+ the 16 runs, something is very wrong. */
+ int ndifferences = 0;
+ int ndefaults = 0;
+ int npartlyrandomized = 0;
+ for (i = 0; i < N; ++i)
+ {
+ if (child_stack_chk_guards[i] != child_stack_chk_guards[i+1])
+ ndifferences++;
+ else if (child_stack_chk_guards[i] == default_guard)
+ ndefaults++;
+ else if (*(char *) &child_stack_chk_guards[i] == 0)
+ npartlyrandomized++;
+ }
+
+ printf ("differences %d defaults %d partly randomized %d\n",
+ ndifferences, ndefaults, npartlyrandomized);
+
+ if ((ndifferences + ndefaults + npartlyrandomized) < 3 * N / 4)
+ {
+ puts ("stack guard canaries are not randomized enough");
+ puts ("nor equal to the default canary value");
+ return 1;
+ }
+
+ return 0;
+}
+
+#define OPT_COMMAND 10000
+#define OPT_CHILD 10001
+#define CMDLINE_OPTIONS \
+ { "command", required_argument, NULL, OPT_COMMAND }, \
+ { "child", no_argument, NULL, OPT_CHILD },
+#define CMDLINE_PROCESS \
+ case OPT_COMMAND: \
+ command = optarg; \
+ break; \
+ case OPT_CHILD: \
+ child = true; \
+ break;
+#define TEST_FUNCTION do_test ()
+#include "../test-skeleton.c"