[1/2] linux: Split tst-ttyname

  The tst-ttyname-direct.c checks the ttyname with procfs mounted in
bind mode (MS_BIND|MS_REC), while tst-ttyname-namespace.c checks
with procfs mount with MS_NOSUID|MS_NOEXEC|MS_NODEV in a new
namespace.

Checked on x86_64-linux-gnu and aarch64-linux-gnu.
---
 sysdeps/unix/sysv/linux/Makefile              |   3 +-
 .../{tst-ttyname.c => tst-ttyname-common.c}   | 208 +-----------------
 sysdeps/unix/sysv/linux/tst-ttyname-direct.c  | 110 +++++++++
 .../unix/sysv/linux/tst-ttyname-namespace.c   | 143 ++++++++++++
 4 files changed, 259 insertions(+), 205 deletions(-)
 rename sysdeps/unix/sysv/linux/{tst-ttyname.c => tst-ttyname-common.c} (68%)
 create mode 100644 sysdeps/unix/sysv/linux/tst-ttyname-direct.c
 create mode 100644 sysdeps/unix/sysv/linux/tst-ttyname-namespace.c
  

On 2023-06-12 14:30, Adhemerval Zanella via Libc-alpha wrote:
> The tst-ttyname-direct.c checks the ttyname with procfs mounted in
> bind mode (MS_BIND|MS_REC), while tst-ttyname-namespace.c checks
> with procfs mount with MS_NOSUID|MS_NOEXEC|MS_NODEV in a new
> namespace.
> 
> Checked on x86_64-linux-gnu and aarch64-linux-gnu.
> ---

LGTM.

Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>

>   sysdeps/unix/sysv/linux/Makefile              |   3 +-
>   .../{tst-ttyname.c => tst-ttyname-common.c}   | 208 +-----------------
>   sysdeps/unix/sysv/linux/tst-ttyname-direct.c  | 110 +++++++++
>   .../unix/sysv/linux/tst-ttyname-namespace.c   | 143 ++++++++++++
>   4 files changed, 259 insertions(+), 205 deletions(-)
>   rename sysdeps/unix/sysv/linux/{tst-ttyname.c => tst-ttyname-common.c} (68%)
>   create mode 100644 sysdeps/unix/sysv/linux/tst-ttyname-direct.c
>   create mode 100644 sysdeps/unix/sysv/linux/tst-ttyname-namespace.c
> 
> diff --git a/sysdeps/unix/sysv/linux/Makefile b/sysdeps/unix/sysv/linux/Makefile
> index 594a5dc53e..23a84cf225 100644
> --- a/sysdeps/unix/sysv/linux/Makefile
> +++ b/sysdeps/unix/sysv/linux/Makefile
> @@ -224,7 +224,8 @@ tests += \
>     tst-sysvshm-linux \
>     tst-tgkill \
>     tst-timerfd \
> -  tst-ttyname \
> +  tst-ttyname-direct \
> +  tst-ttyname-namespace \
>     # tests
>   
>   # process_madvise requires CAP_SYS_ADMIN.
> diff --git a/sysdeps/unix/sysv/linux/tst-ttyname.c b/sysdeps/unix/sysv/linux/tst-ttyname-common.c
> similarity index 68%
> rename from sysdeps/unix/sysv/linux/tst-ttyname.c
> rename to sysdeps/unix/sysv/linux/tst-ttyname-common.c
> index ef55665fbe..3f6d8ee944 100644
> --- a/sysdeps/unix/sysv/linux/tst-ttyname.c
> +++ b/sysdeps/unix/sysv/linux/tst-ttyname-common.c
> @@ -1,4 +1,5 @@
> -/* Copyright (C) 2017-2023 Free Software Foundation, Inc.
> +/* Common definitions for ttyname tests.
> +   Copyright (C) 2017-2023 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
> @@ -19,19 +20,16 @@
>   #include <errno.h>
>   #include <fcntl.h>
>   #include <limits.h>
> -#include <sched.h>
> +#include <stdbool.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 <sys/resource.h>
> +#include <sys/stat.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>
> @@ -266,187 +264,6 @@ adjust_file_limit (const char *pty)
>       }
>   }
>   
> -/* 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);
> -  adjust_file_limit (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);
> -  adjust_file_limit (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
> @@ -597,20 +414,3 @@ run_chroot_tests (const char *slavename, int slave)
>     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/tst-ttyname-direct.c b/sysdeps/unix/sysv/linux/tst-ttyname-direct.c
> new file mode 100644
> index 0000000000..04601777d6
> --- /dev/null
> +++ b/sysdeps/unix/sysv/linux/tst-ttyname-direct.c
> @@ -0,0 +1,110 @@
> +/* Copyright (C) 2017-2023 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 <https://www.gnu.org/licenses/>.  */
> +
> +#include <sched.h>
> +#include <sys/prctl.h>
> +
> +#include <support/namespace.h>
> +
> +#include "tst-ttyname-common.c"
> +
> +/* 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);
> +  adjust_file_limit (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_test (void)
> +{
> +  support_become_root ();
> +
> +  do_in_chroot_1 (run_chroot_tests);
> +
> +  return 0;
> +}
> +
> +#include <support/test-driver.c>
> diff --git a/sysdeps/unix/sysv/linux/tst-ttyname-namespace.c b/sysdeps/unix/sysv/linux/tst-ttyname-namespace.c
> new file mode 100644
> index 0000000000..1f38442747
> --- /dev/null
> +++ b/sysdeps/unix/sysv/linux/tst-ttyname-namespace.c
> @@ -0,0 +1,143 @@
> +/* Tests for ttyname/ttyname_r with namespaces.
> +   Copyright (C) 2017-2023 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 <https://www.gnu.org/licenses/>.  */
> +
> +#include <sched.h>
> +#include <sys/prctl.h>
> +#include <sys/wait.h>
> +
> +#include <support/namespace.h>
> +
> +#include "tst-ttyname-common.c"
> +
> +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);
> +  adjust_file_limit (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);
> +}
> +
> +static int
> +do_test (void)
> +{
> +  support_become_root ();
> +
> +  do_in_chroot_2 (run_chroot_tests);
> +
> +  return 0;
> +}
> +
> +#include <support/test-driver.c>