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-rw-r--r--sysdeps/unix/sysv/linux/Makefile3
-rw-r--r--sysdeps/unix/sysv/linux/getcwd.c8
-rw-r--r--sysdeps/unix/sysv/linux/ia64/ipc_priv.h21
-rw-r--r--sysdeps/unix/sysv/linux/ia64/mmap_internal.h29
-rw-r--r--sysdeps/unix/sysv/linux/m68k/mmap_internal.h2
-rw-r--r--sysdeps/unix/sysv/linux/mmap.c2
-rw-r--r--sysdeps/unix/sysv/linux/mmap_internal.h6
-rw-r--r--sysdeps/unix/sysv/linux/powerpc/not-errno.h30
-rw-r--r--sysdeps/unix/sysv/linux/tst-ttyname.c577
-rw-r--r--sysdeps/unix/sysv/linux/ttyname.c63
-rw-r--r--sysdeps/unix/sysv/linux/ttyname.h18
-rw-r--r--sysdeps/unix/sysv/linux/ttyname_r.c65
12 files changed, 728 insertions, 96 deletions
diff --git a/sysdeps/unix/sysv/linux/Makefile b/sysdeps/unix/sysv/linux/Makefile
index dbe6a36c57..b1fe960d00 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).
 
diff --git a/sysdeps/unix/sysv/linux/getcwd.c b/sysdeps/unix/sysv/linux/getcwd.c
index 3b556fd450..f485de88a5 100644
--- a/sysdeps/unix/sysv/linux/getcwd.c
+++ b/sysdeps/unix/sysv/linux/getcwd.c
@@ -76,7 +76,7 @@ __getcwd (char *buf, size_t size)
   int retval;
 
   retval = INLINE_SYSCALL (getcwd, 2, path, alloc_size);
-  if (retval >= 0)
+  if (retval > 0 && path[0] == '/')
     {
 #ifndef NO_ALLOCATION
       if (buf == NULL && size == 0)
@@ -92,10 +92,10 @@ __getcwd (char *buf, size_t size)
       return buf;
     }
 
-  /* The system call cannot handle paths longer than a page.
-     Neither can the magic symlink in /proc/self.  Just use the
+  /* The system call either cannot handle paths longer than a page
+     or can succeed without returning an absolute path.  Just use the
      generic implementation right away.  */
-  if (errno == ENAMETOOLONG)
+  if (retval >= 0 || errno == ENAMETOOLONG)
     {
 #ifndef NO_ALLOCATION
       if (buf == NULL && size == 0)
diff --git a/sysdeps/unix/sysv/linux/ia64/ipc_priv.h b/sysdeps/unix/sysv/linux/ia64/ipc_priv.h
new file mode 100644
index 0000000000..e602eea455
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/ia64/ipc_priv.h
@@ -0,0 +1,21 @@
+/* Old SysV permission definition for Linux.  IA64 version.
+   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; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#include <sys/ipc.h>  /* For __key_t  */
+
+#define __IPC_64	0x0
diff --git a/sysdeps/unix/sysv/linux/ia64/mmap_internal.h b/sysdeps/unix/sysv/linux/ia64/mmap_internal.h
new file mode 100644
index 0000000000..dbaaa3f904
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/ia64/mmap_internal.h
@@ -0,0 +1,29 @@
+/* Common mmap definition for Linux implementation.  Linux/ia64 version.
+   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; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#ifndef MMAP_IA64_INTERNAL_LINUX_H
+#define MMAP_IA64_INTERNAL_LINUX_H
+
+/* Linux allows PAGE_SHIFT in range of [12-16] and expect
+   mmap2 offset to be provided in based on the configured pagesize.
+   Determine the shift dynamically with getpagesize.  */
+#define MMAP2_PAGE_UNIT -1
+
+#include_next <mmap_internal.h>
+
+#endif
diff --git a/sysdeps/unix/sysv/linux/m68k/mmap_internal.h b/sysdeps/unix/sysv/linux/m68k/mmap_internal.h
index bd8bd3843b..9fe9d9127d 100644
--- a/sysdeps/unix/sysv/linux/m68k/mmap_internal.h
+++ b/sysdeps/unix/sysv/linux/m68k/mmap_internal.h
@@ -22,7 +22,7 @@
 /* ColdFire and Sun 3 kernels have PAGE_SHIFT set to 13 and expect
    mmap2 offset to be provided in 8K pages.  Determine the shift
    dynamically with getpagesize.  */
-#define MMAP2_PAGE_SHIFT -1
+#define MMAP2_PAGE_UNIT -1
 
 #include_next <mmap_internal.h>
 
diff --git a/sysdeps/unix/sysv/linux/mmap.c b/sysdeps/unix/sysv/linux/mmap.c
index 98c2f88eb8..59292b6d79 100644
--- a/sysdeps/unix/sysv/linux/mmap.c
+++ b/sysdeps/unix/sysv/linux/mmap.c
@@ -21,9 +21,9 @@
 #include <sys/mman.h>
 #include <sysdep.h>
 #include <stdint.h>
-#include <mmap_internal.h>
 
 #ifndef __OFF_T_MATCHES_OFF64_T
+# include <mmap_internal.h>
 
 /* An architecture may override this.  */
 # ifndef MMAP_ADJUST_OFFSET
diff --git a/sysdeps/unix/sysv/linux/mmap_internal.h b/sysdeps/unix/sysv/linux/mmap_internal.h
index 499e389605..47c099183c 100644
--- a/sysdeps/unix/sysv/linux/mmap_internal.h
+++ b/sysdeps/unix/sysv/linux/mmap_internal.h
@@ -27,13 +27,13 @@
 #endif
 
 #if MMAP2_PAGE_UNIT == -1
-static int page_unit;
-
+static uint64_t page_unit;
 # define MMAP_CHECK_PAGE_UNIT()			\
   if (page_unit == 0)				\
     page_unit = __getpagesize ();
+# undef MMAP2_PAGE_UNIT
+# define MMAP2_PAGE_UNIT page_unit
 #else
-# define page_unit MMAP2_PAGE_UNIT
 # define MMAP_CHECK_PAGE_UNIT()
 #endif
 
diff --git a/sysdeps/unix/sysv/linux/powerpc/not-errno.h b/sysdeps/unix/sysv/linux/powerpc/not-errno.h
new file mode 100644
index 0000000000..27da21bdf1
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/powerpc/not-errno.h
@@ -0,0 +1,30 @@
+/* Syscall wrapper that do not set errno.  Linux powerpc version.
+   Copyright (C) 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/>.  */
+
+/* __access_noerrno is used during process initialization in elf/dl-tunables.c
+   before the TCB is initialized, prohibiting the usage of
+   ABORT_TRANSACTION.  */
+#undef ABORT_TRANSACTION
+#define ABORT_TRANSACTION
+
+#include "sysdeps/unix/sysv/linux/not-errno.h"
+
+/* Recover ABORT_TRANSACTION's previous value, in order to not affect
+   other syscalls.  */
+#undef ABORT_TRANSACTION
+#define ABORT_TRANSACTION ABORT_TRANSACTION_IMPL
diff --git a/sysdeps/unix/sysv/linux/tst-ttyname.c b/sysdeps/unix/sysv/linux/tst-ttyname.c
new file mode 100644
index 0000000000..6848a6d3e2
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/tst-ttyname.c
@@ -0,0 +1,577 @@
+/* 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
+touch (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 *
+proc_fd_readlink (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;
+}
+
+/* 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)
+{
+  char *actual_name, *expected_name;
+
+  if ((actual.err == expected.err) &&
+      (!actual.name == !expected.name) &&
+      (actual.name ? strcmp (actual.name, expected.name) == 0 : true))
+    {
+      if (expected.name)
+        expected_name = xasprintf ("\"%s\"", expected.name);
+      else
+	expected_name = xstrdup ("NULL");
+
+      printf ("info:      ttyname: PASS {name=%s, errno=%d}\n",
+	      expected_name, expected.err);
+
+      free (expected_name);
+      return true;
+    }
+
+  if (actual.name)
+    actual_name = xasprintf ("\"%s\"", actual.name);
+  else
+    actual_name = xstrdup ("NULL");
+
+  if (expected.name)
+    expected_name = xasprintf ("\"%s\"", expected.name);
+  else
+    expected_name = xstrdup ("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)
+{
+  char *actual_name, *expected_name;
+
+  if ((actual.err == expected.err) &&
+      (actual.ret == expected.ret) &&
+      (!actual.name == !expected.name) &&
+      (actual.name ? strcmp (actual.name, expected.name) == 0 : true))
+    {
+      if (expected.name)
+        expected_name = xasprintf ("\"%s\"", expected.name);
+      else
+        expected_name = xstrdup ("NULL");
+
+      printf ("info:      ttyname_r: PASS {name=%s, ret=%d, errno=%d}\n",
+              expected_name, expected.ret, expected.err);
+
+      free (expected_name);
+      return true;
+    }
+
+  if (actual.name)
+    actual_name = xasprintf ("\"%s\"", actual.name);
+  else
+    actual_name = xstrdup ("NULL");
+
+  if (expected.name)
+    expected_name = xasprintf ("\"%s\"", expected.name);
+  else
+    expected_name = xstrdup ("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);
+
+  if (!eq_ttyname (run_ttyname (fd), expected))
+    ret = false;
+  if (!eq_ttyname_r (run_ttyname_r (fd), expected_r))
+    ret = false;
+
+  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;
+  master = posix_openpt (O_RDWR|O_NOCTTY|O_NONBLOCK);
+  if (master < 0)
+    {
+      if (errno == ENOENT)
+	FAIL_UNSUPPORTED ("posix_openpt: %m");
+      else
+	FAIL_EXIT1 ("posix_openpt: %m");
+    }
+  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);
+
+      if (!support_enter_mount_namespace ())
+	FAIL_UNSUPPORTED ("could not enter new mount namespace");
+
+      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);
+
+      touch ("console", 0);
+      touch ("dev/console", 0);
+      VERIFY (mount (slavename, "console", NULL, MS_BIND, NULL) == 0);
+
+      xchroot (".");
+
+      char *linkname = xasprintf ("/proc/self/fd/%d", slave);
+      char *target = proc_fd_readlink (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]);
+
+      if (!support_enter_mount_namespace ())
+	FAIL_UNSUPPORTED ("could not enter new mount namespace");
+
+      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);
+
+      touch ("console", 0);
+      touch ("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 = proc_fd_readlink (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 fairly
+     generically does things known to mess up ttyname, and verifies
+     that ttyname copes correctly.  The remaining groups are
+     increasingly convoluted, as we target specific parts of ttyname
+     to try to confuse.  */
+
+  /* Basic tests that it doesn't get confused by multiple devpts
+     instances.  */
+  {
+    VERIFY (stat (slavename, &st) < 0); /* sanity check */
+    if (!doit (slave, "no conflict, no match",
+               (struct result_r){.name=NULL, .ret=ENODEV, .err=ENODEV}))
+      ok = false;
+    VERIFY (mount ("/console", "/dev/console", NULL, MS_BIND, NULL) == 0);
+    if (!doit (slave, "no conflict, console",
+               (struct result_r){.name="/dev/console", .ret=0, .err=0}))
+      ok = false;
+    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);
+
+    if (!doit (slave, "conflict, no match",
+               (struct result_r){.name=NULL, .ret=ENODEV, .err=ENODEV}))
+      ok = false;
+    VERIFY (mount ("/console", "/dev/console", NULL, MS_BIND, NULL) == 0);
+    if (!doit (slave, "conflict, console",
+               (struct result_r){.name="/dev/console", .ret=0, .err=0}))
+      ok = false;
+    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 = proc_fd_readlink (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").  We test it both ways (do_in_chroot_1
+       and do_in_chroot_2).  This test group relies on the target
+       existing, so guarantee that it does exist by creating it if
+       necessary.  */
+    if (stat (target, &st) < 0)
+      {
+        VERIFY (errno == ENOENT);
+        touch (target, 0);
+      }
+
+    VERIFY (mount ("/console", "/dev/console", NULL, MS_BIND, NULL) == 0);
+    VERIFY (mount ("/console", target, NULL, MS_BIND, NULL) == 0);
+    if (!doit (slave, "with readlink target",
+               (struct result_r){.name=target, .ret=0, .err=0}))
+      ok = false;
+    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);
+    if (!doit (slave, "with readlink trap; fallback",
+               (struct result_r){.name="/dev/console", .ret=0, .err=0}))
+      ok = false;
+    VERIFY (umount (target) == 0);
+    VERIFY (umount ("/dev/console") == 0);
+
+    VERIFY (mount (slavename, target, NULL, MS_BIND, NULL) == 0);
+    if (!doit (slave, "with readlink trap; no fallback",
+               (struct result_r){.name=NULL, .ret=ENODEV, .err=ENODEV}))
+      ok = false;
+    VERIFY (umount (target) == 0);
+  }
+
+  /* This test makes sure that everything still works OK if readdir
+     finds a pseudo-match before and/or after the actual match.  Now,
+     to do that, we need to control that readdir finds the
+     pseudo-matches before and after the actual match; and there's no
+     good way to control that order in absence of whitebox testing.
+     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; assigning the first to be a pseudo-match, the second to be
+     the actual match, and the third to be a pseudo-match.  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);
+
+    touch ("/dev/console1", 0);
+    touch ("/dev/console2", 0);
+    touch ("/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);
+    if (!doit (slave, "with search-path trap",
+               (struct result_r){.name=c[1], .ret=0, .err=0}))
+      ok = false;
+    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)
+{
+  support_become_root ();
+
+  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>
diff --git a/sysdeps/unix/sysv/linux/ttyname.c b/sysdeps/unix/sysv/linux/ttyname.c
index 5909cb765f..f4c955f25b 100644
--- a/sysdeps/unix/sysv/linux/ttyname.c
+++ b/sysdeps/unix/sysv/linux/ttyname.c
@@ -35,16 +35,14 @@
 char *__ttyname;
 #endif
 
-static char *getttyname (const char *dev, dev_t mydev,
-			 ino64_t myino, int save, int *dostat)
-     internal_function;
-
+static char *getttyname (const char *dev, const struct stat64 *mytty,
+			 int save, int *dostat);
 
 libc_freeres_ptr (static char *getttyname_name);
 
 static char *
-internal_function attribute_compat_text_section
-getttyname (const char *dev, dev_t mydev, ino64_t myino, int save, int *dostat)
+attribute_compat_text_section
+getttyname (const char *dev, const struct stat64 *mytty, int save, int *dostat)
 {
   static size_t namelen;
   struct stat64 st;
@@ -65,7 +63,7 @@ getttyname (const char *dev, dev_t mydev, ino64_t myino, int save, int *dostat)
     *((char *) __mempcpy (getttyname_name, dev, devlen - 1)) = '/';
 
   while ((d = __readdir64 (dirstream)) != NULL)
-    if ((d->d_fileno == myino || *dostat)
+    if ((d->d_fileno == mytty->st_ino || *dostat)
 	&& strcmp (d->d_name, "stdin")
 	&& strcmp (d->d_name, "stdout")
 	&& strcmp (d->d_name, "stderr"))
@@ -87,12 +85,7 @@ getttyname (const char *dev, dev_t mydev, ino64_t myino, int save, int *dostat)
 	  }
 	memcpy (&getttyname_name[devlen], d->d_name, dlen);
 	if (__xstat64 (_STAT_VER, getttyname_name, &st) == 0
-#ifdef _STATBUF_ST_RDEV
-	    && S_ISCHR (st.st_mode) && st.st_rdev == mydev
-#else
-	    && d->d_fileno == myino && st.st_dev == mydev
-#endif
-	   )
+	    && is_mytty (mytty, &st))
 	  {
 	    (void) __closedir (dirstream);
 #if 0
@@ -122,6 +115,7 @@ ttyname (int fd)
   char procname[30];
   struct stat64 st, st1;
   int dostat = 0;
+  int doispty = 0;
   char *name;
   int save = errno;
   struct termios term;
@@ -169,30 +163,15 @@ ttyname (int fd)
       /* Verify readlink result, fall back on iterating through devices.  */
       if (ttyname_buf[0] == '/'
 	  && __xstat64 (_STAT_VER, ttyname_buf, &st1) == 0
-#ifdef _STATBUF_ST_RDEV
-	  && S_ISCHR (st1.st_mode)
-	  && st1.st_rdev == st.st_rdev
-#endif
-	  && st1.st_ino == st.st_ino
-	  && st1.st_dev == st.st_dev)
+	  && is_mytty (&st, &st1))
 	return ttyname_buf;
 
-      /* If the link doesn't exist, then it points to a device in another
-	 namespace. */
-      if (is_pty (&st))
-	{
-	  __set_errno (ENODEV);
-	  return NULL;
-	}
+      doispty = 1;
     }
 
   if (__xstat64 (_STAT_VER, "/dev/pts", &st1) == 0 && S_ISDIR (st1.st_mode))
     {
-#ifdef _STATBUF_ST_RDEV
-      name = getttyname ("/dev/pts", st.st_rdev, st.st_ino, save, &dostat);
-#else
-      name = getttyname ("/dev/pts", st.st_dev, st.st_ino, save, &dostat);
-#endif
+      name = getttyname ("/dev/pts", &st, save, &dostat);
     }
   else
     {
@@ -202,21 +181,23 @@ ttyname (int fd)
 
   if (!name && dostat != -1)
     {
-#ifdef _STATBUF_ST_RDEV
-      name = getttyname ("/dev", st.st_rdev, st.st_ino, save, &dostat);
-#else
-      name = getttyname ("/dev", st.st_dev, st.st_ino, save, &dostat);
-#endif
+      name = getttyname ("/dev", &st, save, &dostat);
     }
 
   if (!name && dostat != -1)
     {
       dostat = 1;
-#ifdef _STATBUF_ST_RDEV
-      name = getttyname ("/dev", st.st_rdev, st.st_ino, save, &dostat);
-#else
-      name = getttyname ("/dev", st.st_dev, st.st_ino, save, &dostat);
-#endif
+      name = getttyname ("/dev", &st, save, &dostat);
+    }
+
+  if (!name && doispty && is_pty (&st))
+    {
+      /* We failed to figure out the TTY's name, but we can at least
+         signal that we did verify that it really is a PTY slave.
+         This happens when we have inherited the file descriptor from
+         a different mount namespace.  */
+      __set_errno (ENODEV);
+      return NULL;
     }
 
   return name;
diff --git a/sysdeps/unix/sysv/linux/ttyname.h b/sysdeps/unix/sysv/linux/ttyname.h
index 2e415e4e9c..48181330a9 100644
--- a/sysdeps/unix/sysv/linux/ttyname.h
+++ b/sysdeps/unix/sysv/linux/ttyname.h
@@ -16,13 +16,15 @@
    not, see <http://www.gnu.org/licenses/>.  */
 
 #include <unistd.h>
+#include <stdbool.h>
 #include <sys/sysmacros.h>
 #include <sys/types.h>
 #include <sys/stat.h>
 
 /* Return true if this is a UNIX98 pty device, as defined in
-   linux/Documentation/devices.txt.  */
-static inline int
+   linux/Documentation/devices.txt (on linux < 4.10) or
+   linux/Documentation/admin-guide/devices.txt (on linux >= 4.10).  */
+static inline bool
 is_pty (struct stat64 *sb)
 {
 #ifdef _STATBUF_ST_RDEV
@@ -32,3 +34,15 @@ is_pty (struct stat64 *sb)
   return false;
 #endif
 }
+
+static inline bool
+is_mytty (const struct stat64 *mytty, const struct stat64 *maybe)
+{
+  return (maybe->st_ino == mytty->st_ino
+	  && maybe->st_dev == mytty->st_dev
+#ifdef _STATBUF_ST_RDEV
+	  && S_ISCHR (maybe->st_mode)
+	  && maybe->st_rdev == mytty->st_rdev
+#endif
+	  );
+}
diff --git a/sysdeps/unix/sysv/linux/ttyname_r.c b/sysdeps/unix/sysv/linux/ttyname_r.c
index dc863526ba..00eefc2c5c 100644
--- a/sysdeps/unix/sysv/linux/ttyname_r.c
+++ b/sysdeps/unix/sysv/linux/ttyname_r.c
@@ -31,12 +31,12 @@
 #include "ttyname.h"
 
 static int getttyname_r (char *buf, size_t buflen,
-			 dev_t mydev, ino64_t myino, int save,
-			 int *dostat) internal_function;
+			 const struct stat64 *mytty, int save,
+			 int *dostat);
 
 static int
-internal_function attribute_compat_text_section
-getttyname_r (char *buf, size_t buflen, dev_t mydev, ino64_t myino,
+attribute_compat_text_section
+getttyname_r (char *buf, size_t buflen, const struct stat64 *mytty,
 	      int save, int *dostat)
 {
   struct stat64 st;
@@ -52,7 +52,7 @@ getttyname_r (char *buf, size_t buflen, dev_t mydev, ino64_t myino,
     }
 
   while ((d = __readdir64 (dirstream)) != NULL)
-    if ((d->d_fileno == myino || *dostat)
+    if ((d->d_fileno == mytty->st_ino || *dostat)
 	&& strcmp (d->d_name, "stdin")
 	&& strcmp (d->d_name, "stdout")
 	&& strcmp (d->d_name, "stderr"))
@@ -72,12 +72,7 @@ getttyname_r (char *buf, size_t buflen, dev_t mydev, ino64_t myino,
 	cp[0] = '\0';
 
 	if (__xstat64 (_STAT_VER, buf, &st) == 0
-#ifdef _STATBUF_ST_RDEV
-	    && S_ISCHR (st.st_mode) && st.st_rdev == mydev
-#else
-	    && d->d_fileno == myino && st.st_dev == mydev
-#endif
-	   )
+	    && is_mytty (mytty, &st))
 	  {
 	    (void) __closedir (dirstream);
 	    __set_errno (save);
@@ -100,6 +95,7 @@ __ttyname_r (int fd, char *buf, size_t buflen)
   char procname[30];
   struct stat64 st, st1;
   int dostat = 0;
+  int doispty = 0;
   int save = errno;
 
   /* Test for the absolute minimal size.  This makes life easier inside
@@ -151,22 +147,10 @@ __ttyname_r (int fd, char *buf, size_t buflen)
       /* Verify readlink result, fall back on iterating through devices.  */
       if (buf[0] == '/'
 	  && __xstat64 (_STAT_VER, buf, &st1) == 0
-#ifdef _STATBUF_ST_RDEV
-	  && S_ISCHR (st1.st_mode)
-	  && st1.st_rdev == st.st_rdev
-#endif
-	  && st1.st_ino == st.st_ino
-	  && st1.st_dev == st.st_dev)
+	  && is_mytty (&st, &st1))
 	return 0;
 
-      /* If the link doesn't exist, then it points to a device in another
-       * namespace.
-       */
-      if (is_pty (&st))
-	{
-	  __set_errno (ENODEV);
-	  return ENODEV;
-	}
+      doispty = 1;
     }
 
   /* Prepare the result buffer.  */
@@ -175,13 +159,8 @@ __ttyname_r (int fd, char *buf, size_t buflen)
 
   if (__xstat64 (_STAT_VER, buf, &st1) == 0 && S_ISDIR (st1.st_mode))
     {
-#ifdef _STATBUF_ST_RDEV
-      ret = getttyname_r (buf, buflen, st.st_rdev, st.st_ino, save,
+      ret = getttyname_r (buf, buflen, &st, save,
 			  &dostat);
-#else
-      ret = getttyname_r (buf, buflen, st.st_dev, st.st_ino, save,
-			  &dostat);
-#endif
     }
   else
     {
@@ -193,26 +172,26 @@ __ttyname_r (int fd, char *buf, size_t buflen)
     {
       buf[sizeof ("/dev/") - 1] = '\0';
       buflen += sizeof ("pts/") - 1;
-#ifdef _STATBUF_ST_RDEV
-      ret = getttyname_r (buf, buflen, st.st_rdev, st.st_ino, save,
-			  &dostat);
-#else
-      ret = getttyname_r (buf, buflen, st.st_dev, st.st_ino, save,
+      ret = getttyname_r (buf, buflen, &st, save,
 			  &dostat);
-#endif
     }
 
   if (ret && dostat != -1)
     {
       buf[sizeof ("/dev/") - 1] = '\0';
       dostat = 1;
-#ifdef _STATBUF_ST_RDEV
-      ret = getttyname_r (buf, buflen, st.st_rdev, st.st_ino,
+      ret = getttyname_r (buf, buflen, &st,
 			  save, &dostat);
-#else
-      ret = getttyname_r (buf, buflen, st.st_dev, st.st_ino,
-			  save, &dostat);
-#endif
+    }
+
+  if (ret && doispty && is_pty (&st))
+    {
+      /* We failed to figure out the TTY's name, but we can at least
+         signal that we did verify that it really is a PTY slave.
+         This happens when we have inherited the file descriptor from
+         a different mount namespace.  */
+      __set_errno (ENODEV);
+      return ENODEV;
     }
 
   return ret;