| /* Copyright (C) 2013-2018 Free Software Foundation, Inc. |
| This file is part of the GNU C Library. |
| |
| 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, see |
| <http://www.gnu.org/licenses/>. */ |
| |
| #include <errno.h> |
| #include <stdbool.h> |
| #include <stdio.h> |
| #include <stdlib.h> |
| #include <string.h> |
| #include <sys/wait.h> |
| #include <stackguard-macros.h> |
| #include <tls.h> |
| #include <unistd.h> |
| |
| #ifndef _GNU_SOURCE |
| #define _GNU_SOURCE |
| #endif |
| /* Requires _GNU_SOURCE */ |
| #include <getopt.h> |
| |
| #ifndef POINTER_CHK_GUARD |
| extern uintptr_t __pointer_chk_guard; |
| # define POINTER_CHK_GUARD __pointer_chk_guard |
| #endif |
| |
| static const char *command; |
| static bool child; |
| static uintptr_t ptr_chk_guard_copy; |
| static bool ptr_chk_guard_copy_set; |
| static int fds[2]; |
| |
| static void __attribute__ ((constructor)) |
| con (void) |
| { |
| ptr_chk_guard_copy = POINTER_CHK_GUARD; |
| ptr_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 (!ptr_chk_guard_copy_set) |
| { |
| puts ("constructor has not been run"); |
| return 1; |
| } |
| |
| if (ptr_chk_guard_copy != POINTER_CHK_GUARD) |
| { |
| puts ("POINTER_CHK_GUARD changed between constructor and do_test"); |
| return 1; |
| } |
| |
| if (child) |
| { |
| write (2, &ptr_chk_guard_copy, sizeof (ptr_chk_guard_copy)); |
| return 0; |
| } |
| |
| if (command == NULL) |
| { |
| puts ("missing --command or --child argument"); |
| return 1; |
| } |
| |
| #define N 16 |
| uintptr_t child_ptr_chk_guards[N + 1]; |
| child_ptr_chk_guards[N] = ptr_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 (ptr_chk_guard_copy != POINTER_CHK_GUARD) |
| { |
| puts ("POINTER_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_ptr_chk_guards[i], |
| sizeof (uintptr_t))) != sizeof (uintptr_t)) |
| { |
| puts ("could not read ptr_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_ptr_chk_guards, N + 1, sizeof (uintptr_t), uintptr_t_cmp); |
| |
| /* The default pointer guard is the same as the default stack guard. |
| They are only set to default if dl_random is NULL. */ |
| 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 pointer guard canaries are either randomized, |
| or equal to the default pointer guard value. |
| Even with randomized pointer 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; |
| for (i = 0; i < N; ++i) |
| { |
| if (child_ptr_chk_guards[i] != child_ptr_chk_guards[i+1]) |
| ndifferences++; |
| else if (child_ptr_chk_guards[i] == default_guard) |
| ndefaults++; |
| } |
| |
| printf ("differences %d defaults %d\n", ndifferences, ndefaults); |
| |
| if (ndifferences < N / 2 && ndefaults < N / 2) |
| { |
| puts ("pointer guard values are not randomized enough"); |
| puts ("nor equal to the default 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 }, |
| |
| static void __attribute((used)) |
| cmdline_process_function (int c) |
| { |
| switch (c) |
| { |
| case OPT_COMMAND: |
| command = optarg; |
| break; |
| case OPT_CHILD: |
| child = true; |
| break; |
| } |
| } |
| |
| #define CMDLINE_PROCESS cmdline_process_function |
| |
| #include <support/test-driver.c> |