[PATCH v2 5/5] linux ttyname and ttyname_r: Add tests [BZ #22145]

[Luke Shumaker <lukeshu at parabola dot nu>]

Add a new tst-ttyname test that includes several named sub-testcases.

This patch is ordered the fixes it tests for are applied (to avoid
breaking `git bisect`), but for reference, here's how each relevent
change so far affected the testcases in this commit:

  |                                 | before  |         | make tests | don't |
  |                                 | 15e9a4f | 15e9a4f | consistent | bail  |
  |---------------------------------+---------+---------+------------+-------|
  | basic smoketest                 | PASS    | PASS    | PASS       | PASS  |
  | no conflict, no match           | PASS[1] | PASS    | PASS       | PASS  |
  | no conflict, console            | PASS    | FAIL!   | FAIL       | PASS! |
  | conflict, no match              | FAIL    | PASS!   | PASS       | PASS  |
  | conflict, console               | FAIL    | FAIL    | FAIL       | PASS! |
  | with readlink target            | PASS    | PASS    | PASS       | PASS  |
  | with readlink trap; fallback    | FAIL    | FAIL    | FAIL       | PASS! |
  | with readlink trap; no fallback | FAIL    | PASS!   | PASS       | PASS  |
  | with search-path trap           | FAIL    | FAIL    | PASS!      | PASS  |
  |---------------------------------+---------+---------+------------+-------|
  |                                 | 4/9     | 5/9     | 6/9        | 9/9   |

  [1]: 15e9a4f introduced a semantic that, under certain failure
       conditions, ttyname sets errno=ENODEV, where previously it
       didn't set errno; it's not quite fair to hold "before 15e9a4f"
       ttyname to those new semantics.  This testcase actually fails,
       but would have passed if we tested for the old the semantics.

Each of the failing tests before 15e9a4f is essentially the same bug:
that it returns a PTY slave with the correct minor device number, but
from the wrong devpts filesystem instance.

"15e9a4f" sought to fix this, but missed several of the cases that can
cause this to happen, and also broke the case where both the erroneous
PTY and the correct PTY exist.

v2:
 - Rearranged commit order
 - Fix code style
 - Expanded commit message
 - Pulled xtouch, become-root, and chroot setup into functions
 - Better tracking of test failures
 - Fixed the "with search-path trap" test case
 - Added test cases for the readlink target directly
 - More readable diagnostic output
 - Test with both shared and private procfs
---
 ChangeLog                             |   4 +
 sysdeps/unix/sysv/linux/Makefile      |   3 +-
 sysdeps/unix/sysv/linux/tst-ttyname.c | 582 ++++++++++++++++++++++++++++++++++
 3 files changed, 588 insertions(+), 1 deletion(-)
 create mode 100644 sysdeps/unix/sysv/linux/tst-ttyname.c

diff --git a/ChangeLog b/ChangeLog
index b5d214ae6f..1982a498ce 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,9 @@
 2017-11-02  Luke Shumaker  <lukeshu@parabola.nu>
 
+	[BZ #22145]
+	* sysdeps/unix/sysv/linux/tst-ttyname.c: New file.
+	* sysdeps/unix/sysv/linux/Makefile: Add tst-ttyname to tests.
+
 	[BZ #22145]
 	* sysdeps/unix/sysv/linux/ttyname.c (ttyname):
 	Defer is_pty check until end.
diff --git a/sysdeps/unix/sysv/linux/Makefile b/sysdeps/unix/sysv/linux/Makefile
index 0c8a009b5e..69edb75209 100644
--- a/sysdeps/unix/sysv/linux/Makefile
+++ b/sysdeps/unix/sysv/linux/Makefile
@@ -50,7 +50,8 @@ sysdep_headers += sys/mount.h sys/acct.h sys/sysctl.h \
 		  bits/siginfo-arch.h bits/siginfo-consts-arch.h
 
 tests += tst-clone tst-clone2 tst-clone3 tst-fanotify tst-personality \
-	 tst-quota tst-sync_file_range test-errno-linux tst-sysconf-iov_max
+	 tst-quota tst-sync_file_range tst-sysconf-iov_max tst-ttyname \
+	 test-errno-linux
 
 # Generate the list of SYS_* macros for the system calls (__NR_*
 # macros).  The file syscall-names.list contains all possible system
diff --git a/sysdeps/unix/sysv/linux/tst-ttyname.c b/sysdeps/unix/sysv/linux/tst-ttyname.c
new file mode 100644
index 0000000000..45d356cab4
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/tst-ttyname.c
@@ -0,0 +1,582 @@
+/* Copyright (C) 2017 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; see the file COPYING.LIB.  If
+   not, see <http://www.gnu.org/licenses/>.  */
+
+#include <dirent.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <limits.h>
+#include <sched.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/mount.h>
+#include <sys/prctl.h>
+#include <sys/stat.h>
+#include <sys/wait.h>
+#include <unistd.h>
+
+#include <support/check.h>
+#include <support/namespace.h>
+#include <support/support.h>
+#include <support/temp_file.h>
+#include <support/test-driver.h>
+#include <support/xunistd.h>
+
+/* generic utilities */
+
+#define VERIFY(expr)                                                    \
+  do {                                                                  \
+    if (!(expr))                                                        \
+      {                                                                 \
+        printf ("error: %s:%d: %s: %m\n",                               \
+                __FILE__, __LINE__, #expr);                             \
+        exit (1);                                                       \
+      }                                                                 \
+  } while (0)
+
+static void
+xtouch (const char *path, mode_t mode)
+{
+  xclose (xopen (path, O_WRONLY|O_CREAT|O_NOCTTY, mode));
+}
+
+static size_t
+trim_prefix (char *str, size_t str_len, const char *prefix)
+{
+  size_t prefix_len = strlen (prefix);
+  if (str_len > prefix_len && memcmp (str, prefix, prefix_len) == 0)
+    {
+      memmove (str, str + prefix_len, str_len - prefix_len);
+      return str_len - prefix_len;
+    }
+  return str_len;
+}
+
+/* returns a pointer to static storage */
+static char *
+xreadlink (const char *linkname)
+{
+  static char target[PATH_MAX+1];
+  ssize_t target_len = readlink (linkname, target, PATH_MAX);
+  VERIFY (target_len > 0);
+  target_len = trim_prefix (target, target_len, "(unreachable)");
+  target[target_len] = '\0';
+  return target;
+}
+
+static void
+become_root_in_mount_ns (void) {
+  uid_t orig_uid = getuid ();
+  gid_t orig_gid = getgid ();
+
+  support_become_root ();
+
+  if (unshare (CLONE_NEWNS) < 0)
+    FAIL_UNSUPPORTED ("could not enter new mount namespace");
+
+  /* support_become_root might have put us in a new user namespace;
+     most filesystems (including tmpfs) don't allow file or directory
+     creation from a user namespace unless uid and gid maps are set,
+     even if we have root privileges in the namespace (failing with
+     EOVERFLOW, since the uid overflows the empty (0-length) uid map).
+
+     Also, stat always reports that uid and gid maps are empty, so we
+     have to try actually reading from them to check if they are
+     empty. */
+  int fd;
+
+  if ((fd = open ("/proc/self/uid_map", O_RDWR, 0)) >= 0)
+    {
+      char buf;
+      if (read (fd, &buf, 1) == 0)
+	{
+	  char *str = xasprintf ("0 %ld 1\n", (long)orig_uid);
+	  if (write (fd, str, strlen (str)) < 0)
+	    FAIL_EXIT1 ("write (uid_map, \"%s\"): %m", str);
+	  free (str);
+	}
+      xclose (fd);
+    }
+
+  /* Oh, but we can't set the gid map until we turn off setgroups. */
+  if ((fd = open ("/proc/self/setgroups", O_WRONLY, 0)) >= 0)
+    {
+      const char *str = "deny";
+      if (write (fd, str, strlen (str)) < 0)
+	FAIL_EXIT1 ("write (setroups, \"%s\"): %m", str);
+      xclose (fd);
+    }
+
+  if ((fd = open ("/proc/self/gid_map", O_RDWR, 0)) >= 0)
+    {
+      char buf;
+      if (read (fd, &buf, 1) == 0)
+	{
+	  char *str = xasprintf ("0 %ld 1\n", (long)orig_gid);
+	  if (write (fd, str, strlen (str)) < 0)
+	    FAIL_EXIT1 ("write (gid_map, \"%s\"): %m", str);
+	  free (str);
+	}
+      xclose (fd);
+    }
+}
+
+/* plain ttyname runner */
+
+struct result {
+  const char *name;
+  int err;
+};
+
+/* strings in result structure are in static storage */
+static struct result
+run_ttyname (int fd)
+{
+  struct result ret;
+  errno = 0;
+  ret.name = ttyname (fd);
+  ret.err = errno;
+  return ret;
+}
+
+static bool
+eq_ttyname (struct result actual, struct result expected)
+{
+  if ((actual.err == expected.err) &&
+      (!actual.name == !expected.name) &&
+      (actual.name ? strcmp (actual.name, expected.name) == 0 : true))
+    {
+      char *name = expected.name
+	? xasprintf ("\"%s\"", expected.name)
+	: strdup ("NULL");
+      printf ("info:      ttyname: PASS {name=%s, errno=%d}\n",
+	      name, expected.err);
+      free (name);
+      return true;
+    }
+
+  char *actual_name = actual.name
+    ? xasprintf ("\"%s\"", actual.name)
+    : strdup ("NULL");
+  char *expected_name = expected.name
+    ? xasprintf ("\"%s\"", expected.name)
+    : strdup ("NULL");
+  printf ("error:     ttyname: actual {name=%s, errno=%d} != expected {name=%s, errno=%d}\n",
+	  actual_name, actual.err,
+	  expected_name, expected.err);
+  free (actual_name);
+  free (expected_name);
+  return false;
+}
+
+/* ttyname_r runner */
+
+struct result_r {
+  const char *name;
+  int ret;
+  int err;
+};
+
+/* strings in result structure are in static storage */
+static struct result_r
+run_ttyname_r (int fd)
+{
+  static char buf[TTY_NAME_MAX];
+
+  struct result_r ret;
+  errno = 0;
+  ret.ret = ttyname_r (fd, buf, TTY_NAME_MAX);
+  ret.err = errno;
+  if (ret.ret == 0)
+    ret.name = buf;
+  else
+    ret.name = NULL;
+  return ret;
+}
+
+static bool
+eq_ttyname_r (struct result_r actual, struct result_r expected)
+{
+  if ((actual.err == expected.err) &&
+      (actual.ret == expected.ret) &&
+      (!actual.name == !expected.name) &&
+      (actual.name ? strcmp (actual.name, expected.name) == 0 : true))
+    {
+      char *name = expected.name
+	? xasprintf ("\"%s\"", expected.name)
+	: strdup ("NULL");
+      printf ("info:      ttyname_r: PASS {name=%s, ret=%d, errno=%d}\n",
+              name, expected.ret, expected.err);
+      free (name);
+      return true;
+    }
+
+  char *actual_name = actual.name
+    ? xasprintf ("\"%s\"", actual.name)
+    : strdup ("NULL");
+  char *expected_name = expected.name
+    ? xasprintf ("\"%s\"", expected.name)
+    : strdup ("NULL");
+  printf ("error:     ttyname_r: actual {name=%s, ret=%d, errno=%d} != expected {name=%s, ret=%d, errno=%d}\n",
+	  actual_name, actual.ret, actual.err,
+	  expected_name, expected.ret, expected.err);
+  free (actual_name);
+  free (expected_name);
+  return false;
+}
+
+/* combined runner */
+
+static bool
+doit (int fd, const char *testname, struct result_r expected_r) {
+  struct result expected = {.name=expected_r.name, .err=expected_r.ret};
+  bool ret = true;
+
+  printf ("info:    testcase: %s\n", testname);
+
+  ret = eq_ttyname (run_ttyname (fd), expected) && ret;
+  ret = eq_ttyname_r (run_ttyname_r (fd), expected_r) && ret;
+
+  if (!ret)
+    support_record_failure ();
+
+  return ret;
+}
+
+/* chroot setup */
+
+static char *chrootdir;
+
+static void
+prepare (int argc, char **argv)
+{
+  chrootdir = xasprintf ("%s/tst-ttyname-XXXXXX", test_dir);
+  if (mkdtemp (chrootdir) == NULL)
+    FAIL_EXIT1 ("mkdtemp (\"%s\"): %m", chrootdir);
+  add_temp_file (chrootdir);
+}
+#define PREPARE prepare
+
+/* These chroot setup functions put the TTY at at "/console" (where it
+   won't be found by ttyname), and create "/dev/console" as an
+   ordinary file.  This way, it's easier to write test-cases that
+   expect ttyname to fail; test-cases that expect it to succeed need
+   to explicitly remount it at "/dev/console". */
+
+static int
+do_in_chroot_1 (int (*cb)(const char *, int)) {
+  printf ("info:  entering chroot 1\n");
+
+  /* Open the PTS that we'll be testing on. */
+  int master;
+  char *slavename;
+  VERIFY ((master = posix_openpt (O_RDWR|O_NOCTTY|O_NONBLOCK)) >= 0);
+  VERIFY ((slavename = ptsname (master)));
+  VERIFY (unlockpt (master) == 0);
+  if (strncmp (slavename, "/dev/pts/", 9) != 0)
+    FAIL_UNSUPPORTED ("slave pseudo-terminal is not under /dev/pts/: %s",
+                      slavename);
+  int slave = xopen (slavename, O_RDWR, 0);
+  if (!doit (slave, "basic smoketest",
+             (struct result_r){.name=slavename, .ret=0, .err=0}))
+    return 1;
+
+  pid_t pid = xfork ();
+  if (pid == 0)
+    {
+      xclose (master);
+
+      become_root_in_mount_ns ();
+
+      VERIFY (mount ("tmpfs", chrootdir, "tmpfs", 0, "mode=755") == 0);
+      VERIFY (chdir (chrootdir) == 0);
+
+      xmkdir ("proc", 0755);
+      xmkdir ("dev", 0755);
+      xmkdir ("dev/pts", 0755);
+
+      VERIFY (mount ("/proc", "proc", NULL, MS_BIND|MS_REC, NULL) == 0);
+      VERIFY (mount ("devpts", "dev/pts", "devpts",
+                     MS_NOSUID|MS_NOEXEC,
+                     "newinstance,ptmxmode=0666,mode=620") == 0);
+      VERIFY (symlink ("pts/ptmx", "dev/ptmx") == 0);
+
+      xtouch ("console", 0);
+      xtouch ("dev/console", 0);
+      VERIFY (mount (slavename, "console", NULL, MS_BIND, NULL) == 0);
+
+      xchroot (".");
+
+      char *linkname = xasprintf ("/proc/self/fd/%d", slave);
+      char *target = xreadlink (linkname);
+      VERIFY (strcmp (target, slavename) == 0);
+      free (linkname);
+
+      _exit (cb (slavename, slave));
+    }
+  int status;
+  xwaitpid (pid, &status, 0);
+  VERIFY (WIFEXITED (status));
+  xclose (master);
+  xclose (slave);
+  return WEXITSTATUS (status);
+}
+
+static int
+do_in_chroot_2 (int (*cb)(const char *, int)) {
+  printf ("info:  entering chroot 2\n");
+
+  int pid_pipe[2];
+  xpipe (pid_pipe);
+  int exit_pipe[2];
+  xpipe (exit_pipe);
+
+  /* Open the PTS that we'll be testing on. */
+  int master;
+  char *slavename;
+  VERIFY ((master = posix_openpt (O_RDWR|O_NOCTTY|O_NONBLOCK)) >= 0);
+  VERIFY ((slavename = ptsname (master)));
+  VERIFY (unlockpt (master) == 0);
+  if (strncmp (slavename, "/dev/pts/", 9) != 0)
+    FAIL_UNSUPPORTED ("slave pseudo-terminal is not under /dev/pts/: %s",
+                      slavename);
+  /* wait until in a new mount ns to open the slave */
+
+  /* enable `wait`ing on grandchildren */
+  VERIFY (prctl (PR_SET_CHILD_SUBREAPER, 1) == 0);
+
+  pid_t pid = xfork (); /* outer child */
+  if (pid == 0)
+    {
+      xclose (master);
+      xclose (pid_pipe[0]);
+      xclose (exit_pipe[1]);
+
+      become_root_in_mount_ns ();
+
+      int slave = xopen (slavename, O_RDWR, 0);
+      if (!doit (slave, "basic smoketest",
+                 (struct result_r){.name=slavename, .ret=0, .err=0}))
+        _exit (1);
+
+      VERIFY (mount ("tmpfs", chrootdir, "tmpfs", 0, "mode=755") == 0);
+      VERIFY (chdir (chrootdir) == 0);
+
+      xmkdir ("proc", 0755);
+      xmkdir ("dev", 0755);
+      xmkdir ("dev/pts", 0755);
+
+      VERIFY (mount ("devpts", "dev/pts", "devpts",
+                     MS_NOSUID|MS_NOEXEC,
+                     "newinstance,ptmxmode=0666,mode=620") == 0);
+      VERIFY (symlink ("pts/ptmx", "dev/ptmx") == 0);
+
+      xtouch ("console", 0);
+      xtouch ("dev/console", 0);
+      VERIFY (mount (slavename, "console", NULL, MS_BIND, NULL) == 0);
+
+      xchroot (".");
+
+      if (unshare (CLONE_NEWNS | CLONE_NEWPID) < 0)
+        FAIL_UNSUPPORTED ("could not enter new PID namespace");
+      pid = xfork (); /* inner child */
+      if (pid == 0)
+        {
+          xclose (pid_pipe[1]);
+
+          /* wait until the outer child has exited */
+          char c;
+          VERIFY (read (exit_pipe[0], &c, 1) == 0);
+          xclose (exit_pipe[0]);
+
+          VERIFY (mount ("proc", "/proc", "proc",
+                         MS_NOSUID|MS_NOEXEC|MS_NODEV, NULL) == 0);
+
+          char *linkname = xasprintf ("/proc/self/fd/%d", slave);
+          char *target = xreadlink (linkname);
+          VERIFY (strcmp (target, strrchr (slavename, '/')) == 0);
+          free (linkname);
+
+          _exit (cb (slavename, slave));
+        }
+      xwrite (pid_pipe[1], &pid, sizeof pid);
+      _exit (0);
+    }
+  xclose (pid_pipe[1]);
+  xclose (exit_pipe[0]);
+  xclose (exit_pipe[1]);
+
+  /* wait for the outer child */
+  int status;
+  xwaitpid (pid, &status, 0);
+  VERIFY (WIFEXITED (status));
+  int ret = WEXITSTATUS (status);
+  if (ret != 0)
+    return ret;
+
+  /* set 'pid' to the inner child */
+  VERIFY (read (pid_pipe[0], &pid, sizeof pid) == sizeof pid);
+  xclose (pid_pipe[0]);
+
+  /* wait for the inner child */
+  xwaitpid (pid, &status, 0);
+  VERIFY (WIFEXITED (status));
+  xclose (master);
+  return WEXITSTATUS (status);
+}
+
+/* main test */
+
+static int
+run_chroot_tests (const char *slavename, int slave)
+{
+  struct stat st;
+  bool ok = true;
+
+  /* There are 3 groups of tests here.  The first group throws a
+     wrench into the works in a generic way, and verifies that ttyname
+     copes correctly.  The remaining groups are increasingly
+     convoluted, as we direct that wrench towards specific parts of
+     the routine, and try to break it in specific ways. */
+
+  /* Basic tests that it doesn't get confused by multiple devpts
+     instances. */
+  {
+    VERIFY (stat (slavename, &st) < 0); /* sanity check */
+    ok = doit (slave, "no conflict, no match",
+               (struct result_r){.name=NULL, .ret=ENODEV, .err=ENODEV}) && ok;
+    VERIFY (mount ("/console", "/dev/console", NULL, MS_BIND, NULL) == 0);
+    ok = doit (slave, "no conflict, console",
+               (struct result_r){.name="/dev/console", .ret=0, .err=0}) && ok;
+    VERIFY (umount ("/dev/console") == 0);
+
+    /* keep creating PTYs until we we get a name collision */
+    while (stat (slavename, &st) < 0)
+      posix_openpt (O_RDWR|O_NOCTTY|O_NONBLOCK);
+    VERIFY (stat (slavename, &st) == 0);
+
+    ok = doit (slave, "conflict, no match",
+               (struct result_r){.name=NULL, .ret=ENODEV, .err=ENODEV}) && ok;
+    VERIFY (mount ("/console", "/dev/console", NULL, MS_BIND, NULL) == 0);
+    ok = doit (slave, "conflict, console",
+               (struct result_r){.name="/dev/console", .ret=0, .err=0}) && ok;
+    VERIFY (umount ("/dev/console") == 0);
+  }
+
+  /* The first tests kinda assumed that they hit certain code-paths
+     based on assuming that the readlink target is 'slavename', but
+     that's not quite always true.  They're still a good preliminary
+     sanity check, so keep them, but let's add tests that make sure
+     that those code-paths are hit by doing a readlink ourself. */
+  {
+    char *linkname = xasprintf ("/proc/self/fd/%d", slave);
+    char *target = xreadlink (linkname);
+    free (linkname);
+    /* Depeding on how we set up the chroot, the kernel may or may not
+     * trim the leading path to the target (it may give us "/6",
+     * instead of "/dev/pts/6").  This test group relies on the target
+     * existing, so guarantee that (so create a file at "/6" if
+     * necessary). */
+    if (stat (target, &st) < 0)
+      {
+        VERIFY (errno == ENOENT);
+        xtouch (target, 0);
+      }
+
+    VERIFY (mount ("/console", "/dev/console", NULL, MS_BIND, NULL) == 0);
+    VERIFY (mount ("/console", target, NULL, MS_BIND, NULL) == 0);
+    ok = doit (slave, "with readlink target",
+               (struct result_r){.name=target, .ret=0, .err=0}) && ok;
+    VERIFY (umount (target) == 0);
+    VERIFY (umount ("/dev/console") == 0);
+
+    VERIFY (mount ("/console", "/dev/console", NULL, MS_BIND, NULL) == 0);
+    VERIFY (mount (slavename, target, NULL, MS_BIND, NULL) == 0);
+    ok = doit (slave, "with readlink trap; fallback",
+               (struct result_r){.name="/dev/console", .ret=0, .err=0}) && ok;
+    VERIFY (umount (target) == 0);
+    VERIFY (umount ("/dev/console") == 0);
+
+    VERIFY (mount (slavename, target, NULL, MS_BIND, NULL) == 0);
+    ok = doit (slave, "with readlink trap; no fallback",
+               (struct result_r){.name=NULL, .ret=ENODEV, .err=ENODEV}) && ok;
+    VERIFY (umount (target) == 0);
+  }
+
+  /* This test is extra-convoluted because we need to control the
+     order of files within the directory.  So, just create 3 files,
+     then use opendir/readdir to see what order they are in, and
+     assign meaning based on that order, not by name.  This assumes
+     that (on tmpfs) ordering within the directory is stable in the
+     absence of modification, which seems reasonably safe. */
+  {
+    /* since we're testing the fallback search, disable the readlink
+       happy-path */
+    VERIFY (umount2 ("/proc", MNT_DETACH) == 0);
+
+    xtouch ("/dev/console1", 0);
+    xtouch ("/dev/console2", 0);
+    xtouch ("/dev/console3", 0);
+
+    char *c[3];
+    int ci = 0;
+    DIR *dirstream = opendir ("/dev");
+    VERIFY (dirstream != NULL);
+    struct dirent *d;
+    while ((d = readdir (dirstream)) != NULL && ci < 3)
+      {
+        if (strcmp (d->d_name, "console1") &&
+            strcmp (d->d_name, "console2") &&
+            strcmp (d->d_name, "console3") )
+          continue;
+        c[ci++] = xasprintf ("/dev/%s", d->d_name);
+      }
+    VERIFY (ci == 3);
+    VERIFY (closedir (dirstream) == 0);
+
+    VERIFY (mount (slavename, c[0], NULL, MS_BIND, NULL) == 0);
+    VERIFY (mount ("/console", c[1], NULL, MS_BIND, NULL) == 0);
+    VERIFY (mount (slavename, c[2], NULL, MS_BIND, NULL) == 0);
+    VERIFY (umount2 ("/dev/pts", MNT_DETACH) == 0);
+    ok = doit (slave, "with search-path trap",
+               (struct result_r){.name=c[1], .ret=0, .err=0}) && ok;
+    for (int i = 0; i < 3; i++)
+      {
+        VERIFY (umount (c[i]) == 0);
+        VERIFY (unlink (c[i]) == 0);
+        free (c[i]);
+      }
+  }
+
+  return ok ? 0 : 1;
+}
+
+static int
+do_test (void)
+{
+  int ret1 = do_in_chroot_1 (run_chroot_tests);
+  if (ret1 == EXIT_UNSUPPORTED)
+    return ret1;
+
+  int ret2 = do_in_chroot_2 (run_chroot_tests);
+  if (ret2 == EXIT_UNSUPPORTED)
+    return ret2;
+
+  return  ret1 | ret2;
+}
+
+#include <support/test-driver.c>
-- 
2.15.0