| /* 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 <pthread.h> |
| #include <stdbool.h> |
| #include <stdio.h> |
| #include <stdlib.h> |
| #include <string.h> |
| #include <sys/wait.h> |
| #include <elf/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 void * |
| tf (void *arg) |
| { |
| if (stack_chk_guard_copy != STACK_CHK_GUARD) |
| { |
| puts ("STACK_CHK_GUARD changed in thread"); |
| return (void *) 1L; |
| } |
| return NULL; |
| } |
| |
| 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) |
| { |
| int i; |
| pthread_t th[4]; |
| void *ret; |
| for (i = 0; i < 4; ++i) |
| if (pthread_create (&th[i], NULL, tf, NULL)) |
| { |
| puts ("thread creation failed"); |
| return 1; |
| } |
| for (i = 0; i < 4; ++i) |
| if (pthread_join (th[i], &ret)) |
| { |
| puts ("thread join failed"); |
| return 1; |
| } |
| else if (ret != NULL) |
| return 1; |
| |
| 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; |
| 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++; |
| } |
| |
| printf ("differences %d defaults %d\n", ndifferences, ndefaults); |
| |
| if (ndifferences < N / 2 && ndefaults < N / 2) |
| { |
| 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" |