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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)
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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
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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"