From 5046dbb4a7eba5eccfd258f92f4735c9ffc8d069 Mon Sep 17 00:00:00 2001 From: Zack Weinberg Date: Thu, 8 Jun 2017 15:39:03 -0400 Subject: Prepare for radical source tree reorganization. All top-level files and directories are moved into a temporary storage directory, REORG.TODO, except for files that will certainly still exist in their current form at top level when we're done (COPYING, COPYING.LIB, LICENSES, NEWS, README), all old ChangeLog files (which are moved to the new directory OldChangeLogs, instead), and the generated file INSTALL (which is just deleted; in the new order, there will be no generated files checked into version control). --- REORG.TODO/elf/tst-stackguard1.c | 205 +++++++++++++++++++++++++++++++++++++++ 1 file changed, 205 insertions(+) create mode 100644 REORG.TODO/elf/tst-stackguard1.c (limited to 'REORG.TODO/elf/tst-stackguard1.c') diff --git a/REORG.TODO/elf/tst-stackguard1.c b/REORG.TODO/elf/tst-stackguard1.c new file mode 100644 index 0000000000..78e33c7083 --- /dev/null +++ b/REORG.TODO/elf/tst-stackguard1.c @@ -0,0 +1,205 @@ +/* Copyright (C) 2005-2017 Free Software Foundation, Inc. + This file is part of the GNU C Library. + Contributed by Jakub Jelinek , 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, see + . */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +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; + 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 }, + +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 -- cgit 1.4.1