[PATCH v9] Add static tests for __clone_internal

["H.J. Lu" <hjl.tools@gmail.com>]

On Tue, Jul 13, 2021 at 12:33 PM Adhemerval Zanella
<adhemerval.zanella@linaro.org> wrote:
>
> They are quite similar to the non '-internal' tests, would be better to try
> include and reimplement the difference bits that calls the __clone_internal()
> intead of replicate all the tests?

I'd like to test __clone_internal separately and leave the existing clone
tests alone.

> On 01/06/2021 11:55, H.J. Lu wrote:
> > ---
> >  sysdeps/unix/sysv/linux/Makefile              |   9 ++
> >  .../sysv/linux/tst-align-clone-internal.c     |  87 +++++++++++
> >  sysdeps/unix/sysv/linux/tst-clone2-internal.c | 137 ++++++++++++++++++
> >  sysdeps/unix/sysv/linux/tst-clone3-internal.c |  99 +++++++++++++
> >  .../unix/sysv/linux/tst-getpid1-internal.c    | 133 +++++++++++++++++
> >  .../sysv/linux/tst-misalign-clone-internal.c  |  86 +++++++++++
> >  6 files changed, 551 insertions(+)
> >  create mode 100644 sysdeps/unix/sysv/linux/tst-align-clone-internal.c
> >  create mode 100644 sysdeps/unix/sysv/linux/tst-clone2-internal.c
> >  create mode 100644 sysdeps/unix/sysv/linux/tst-clone3-internal.c
> >  create mode 100644 sysdeps/unix/sysv/linux/tst-getpid1-internal.c
> >  create mode 100644 sysdeps/unix/sysv/linux/tst-misalign-clone-internal.c
> >
> > diff --git a/sysdeps/unix/sysv/linux/Makefile b/sysdeps/unix/sysv/linux/Makefile
> > index 9469868bce..214b912921 100644
> > --- a/sysdeps/unix/sysv/linux/Makefile
> > +++ b/sysdeps/unix/sysv/linux/Makefile
> > @@ -118,6 +118,15 @@ endif
> >
> >  tests-internal += tst-sigcontext-get_pc
> >
> > +tests-clone-internal = \
> > +  tst-align-clone-internal \
> > +  tst-clone2-internal \
> > +  tst-clone3-internal \
> > +  tst-getpid1-internal \
> > +  tst-misalign-clone-internal
> > +tests-internal += $(tests-clone-internal)
> > +tests-static += $(tests-clone-internal)
> > +
> >  CFLAGS-tst-sigcontext-get_pc.c = -fasynchronous-unwind-tables
> >
> >  # Generate the list of SYS_* macros for the system calls (__NR_*
>
> Ok.
>
> > diff --git a/sysdeps/unix/sysv/linux/tst-align-clone-internal.c b/sysdeps/unix/sysv/linux/tst-align-clone-internal.c
> > new file mode 100644
> > index 0000000000..6c3631f3db
> > --- /dev/null
> > +++ b/sysdeps/unix/sysv/linux/tst-align-clone-internal.c
> > @@ -0,0 +1,87 @@
> > +/* Verify that the clone child stack is properly aligned.
> > +   Copyright (C) 2021 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
> > +   <https://www.gnu.org/licenses/>.  */
> > +
> > +#include <sched.h>
> > +#include <stdbool.h>
> > +#include <stdint.h>
> > +#include <stdio.h>
> > +#include <string.h>
> > +#include <sys/wait.h>
> > +#include <unistd.h>
> > +#include <tst-stack-align.h>
> > +#include <clone_internal.h>
> > +#include <support/xunistd.h>
> > +
> > +static int
> > +f (void *arg)
> > +{
> > +  bool ok = true;
> > +
> > +  puts ("in f");
> > +
> > +  if (TEST_STACK_ALIGN ())
> > +    ok = false;
> > +
> > +  return ok ? 0 : 1;
> > +}
>
> Maybe:
>
>   statit int
>   f (void *arg)
>   {
>     return TEST_STACK_ALIGN () ? 0 : 1;
>   }

Fixed.

> > +
> > +static int
> > +do_test (void)
> > +{
> > +  bool ok = true;
> > +
> > +  puts ("in main");
> > +
> > +  if (TEST_STACK_ALIGN ())
> > +    ok = false;
> > +
>
> Maybe
>
>   ok = TEST_STACK_ALIGN ();
>
> But I think this does not really add much, so I think it would be better
> to:
>
>   if (! TEST_STACK_ALIGN ())
>     FAIL_EXIT1 ("stack alignment failed");

Fixed.

> > +#ifdef __ia64__
> > +# define STACK_SIZE 256 * 1024
> > +#else
> > +# define STACK_SIZE 128 * 1024
> > +#endif
> > +  char st[STACK_SIZE] __attribute__ ((aligned));
> > +  struct clone_args clone_args =
> > +    {
> > +      .stack = (uintptr_t) st,
> > +      .stack_size = sizeof (st),
> > +    };
> > +  pid_t p = __clone_internal (&clone_args, f, 0);
> > +  if (p == -1)
> > +    {
> > +      printf("clone failed: %m\n");
> > +      return 1;
> > +    }
>
> Use TEST_VERIFY here:
>
>   TEST_VERIFY (p != -1);

Fixed.

> > +
> > +  int e;
> > +  xwaitpid (p, &e, __WCLONE);
> > +  if (!WIFEXITED (e))
> > +    {
> > +      if (WIFSIGNALED (e))
> > +     printf ("died from signal %s\n", strsignal (WTERMSIG (e)));
> > +      else
> > +     puts ("did not terminate correctly");
> > +      return 1;
> > +    }
> > +  if (WEXITSTATUS (e) != 0)
> > +    ok = false;
>
>     TEST_VERIFY (WIFEXITED (status));
>     TEST_COMPARE (WEXITSTATUS (status), 0);

Fixed.

> > +
> > +  return ok ? 0 : 1;
> > +}
> > +
> > +#include <support/test-driver.c>
> > diff --git a/sysdeps/unix/sysv/linux/tst-clone2-internal.c b/sysdeps/unix/sysv/linux/tst-clone2-internal.c
> > new file mode 100644
> > index 0000000000..b8917fe713
> > --- /dev/null
> > +++ b/sysdeps/unix/sysv/linux/tst-clone2-internal.c
> > @@ -0,0 +1,137 @@
> > +/* Test if CLONE_VM does not change pthread pid/tid field (BZ #19957)
> > +   Copyright (C) 2021 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
> > +   <https://www.gnu.org/licenses/>.  */
> > +
> > +#include <sched.h>
> > +#include <signal.h>
> > +#include <string.h>
> > +#include <stdio.h>
> > +#include <fcntl.h>
> > +#include <unistd.h>
> > +#include <stddef.h>
> > +#include <stdbool.h>
> > +#include <stdint.h>
> > +#include <stdlib.h>
> > +#include <errno.h>
> > +#include <sys/types.h>
> > +#include <sys/wait.h>
> > +#include <sys/syscall.h>
> > +#include <clone_internal.h>
> > +#include <support/xunistd.h>
> > +#include <support/check.h>
> > +
> > +static int sig;
> > +static int pipefd[2];
> > +
> > +static int
> > +f (void *a)
> > +{
> > +  close (pipefd[0]);
> > +
> > +  pid_t ppid = getppid ();
> > +  pid_t pid = getpid ();
> > +  pid_t tid = gettid ();
> > +
> > +  if (write (pipefd[1], &ppid, sizeof ppid) != sizeof (ppid))
> > +    FAIL_EXIT1 ("write ppid failed\n");
> > +  if (write (pipefd[1], &pid, sizeof pid) != sizeof (pid))
> > +    FAIL_EXIT1 ("write pid failed\n");
> > +  if (write (pipefd[1], &tid, sizeof tid) != sizeof (tid))
> > +    FAIL_EXIT1 ("write tid failed\n");
> > +
> > +  return 0;
> > +}
> > +
> > +
> > +static int
> > +do_test (void)
> > +{
> > +  sig = SIGRTMIN;
> > +  sigset_t ss;
> > +  sigemptyset (&ss);
> > +  sigaddset (&ss, sig);
> > +  if (sigprocmask (SIG_BLOCK, &ss, NULL) != 0)
> > +    FAIL_EXIT1 ("sigprocmask failed: %m");
> > +
> > +  if (pipe2 (pipefd, O_CLOEXEC))
> > +    FAIL_EXIT1 ("pipe failed: %m");
> > +
> > +#ifdef __ia64__
> > +# define STACK_SIZE 256 * 1024
> > +#else
> > +# define STACK_SIZE 128 * 1024
> > +#endif
> > +  char st[STACK_SIZE] __attribute__ ((aligned));
> > +  struct clone_args clone_args =
> > +    {
> > +      .stack = (uintptr_t) st,
> > +      .stack_size = sizeof (st),
> > +    };
> > +  pid_t p = __clone_internal (&clone_args, f, 0);
> > +
> > +  close (pipefd[1]);
> > +
> > +  if (p == -1)
> > +    FAIL_EXIT1("clone failed: %m");
> > +
> > +  pid_t ppid, pid, tid;
> > +  if (read (pipefd[0], &ppid, sizeof pid) != sizeof pid)
> > +    {
> > +      kill (p, SIGKILL);
> > +      FAIL_EXIT1 ("read ppid failed: %m");
> > +    }
> > +  if (read (pipefd[0], &pid, sizeof pid) != sizeof pid)
> > +    {
> > +      kill (p, SIGKILL);
> > +      FAIL_EXIT1 ("read pid failed: %m");
> > +    }
> > +  if (read (pipefd[0], &tid, sizeof tid) != sizeof tid)
> > +    {
> > +      kill (p, SIGKILL);
> > +      FAIL_EXIT1 ("read tid failed: %m");
> > +    }
> > +
> > +  close (pipefd[0]);
> > +
> > +  int ret = 0;
> > +
> > +  pid_t own_pid = getpid ();
> > +  pid_t own_tid = syscall (__NR_gettid);
> > +
> > +  /* Some sanity checks for clone syscall: returned ppid should be current
> > +     pid and both returned tid/pid should be different from current one.  */
> > +  if ((ppid != own_pid) || (pid == own_pid) || (tid == own_tid))
> > +    FAIL_RET ("ppid=%i pid=%i tid=%i | own_pid=%i own_tid=%i",
> > +           (int)ppid, (int)pid, (int)tid, (int)own_pid, (int)own_tid);
> > +
> > +  int e;
> > +  xwaitpid (p, &e, __WCLONE);
> > +  if (!WIFEXITED (e))
> > +    {
> > +      if (WIFSIGNALED (e))
> > +     printf ("died from signal %s\n", strsignal (WTERMSIG (e)));
> > +      else
> > +     puts ("did not terminate correctly");
> > +      exit (EXIT_FAILURE);
> > +    }
> > +  if (WEXITSTATUS (e) != 0)
> > +    FAIL_EXIT1 ("exit code %d", WEXITSTATUS (e));
>
>     TEST_VERIFY (WIFEXITED (status));
>     TEST_COMPARE (WEXITSTATUS (status), 0);

Fixed.

> > +
> > +  return ret;
> > +}
> > +
> > +#include <support/test-driver.c>
> > diff --git a/sysdeps/unix/sysv/linux/tst-clone3-internal.c b/sysdeps/unix/sysv/linux/tst-clone3-internal.c
> > new file mode 100644
> > index 0000000000..2bdbc571e6
> > --- /dev/null
> > +++ b/sysdeps/unix/sysv/linux/tst-clone3-internal.c
> > @@ -0,0 +1,99 @@
> > +/* Check if clone (CLONE_THREAD) does not call exit_group (BZ #21512)
> > +   Copyright (C) 2021 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
> > +   <https://www.gnu.org/licenses/>.  */
> > +
> > +#include <string.h>
> > +#include <sched.h>
> > +#include <signal.h>
> > +#include <unistd.h>
> > +#include <errno.h>
> > +#include <sys/syscall.h>
> > +#include <sys/wait.h>
> > +#include <sys/types.h>
> > +#include <linux/futex.h>
> > +#include <support/check.h>
> > +#include <stdatomic.h>
> > +#include <clone_internal.h>
> > +
> > +/* Test if clone call with CLONE_THREAD does not call exit_group.  The 'f'
> > +   function returns '1', which will be used by clone thread to call the
> > +   'exit' syscall directly.  If _exit is used instead, exit_group will be
> > +   used and thus the thread group will finish with return value of '1'
> > +   (where '2' from main thread is expected.).  */
> > +
> > +static int
> > +f (void *a)
> > +{
> > +  return 1;
> > +}
> > +
> > +/* Futex wait for TID argument, similar to pthread_join internal
> > +   implementation.  */
> > +#define wait_tid(ctid_ptr, ctid_val)                                 \
> > +  do {                                                                       \
> > +    __typeof (*(ctid_ptr)) __tid;                                    \
> > +    /* We need acquire MO here so that we synchronize with the               \
> > +       kernel's store to 0 when the clone terminates.  */            \
> > +    while ((__tid = atomic_load_explicit (ctid_ptr,                  \
> > +                                       memory_order_acquire)) != 0)  \
> > +      futex_wait (ctid_ptr, ctid_val);                                       \
> > +  } while (0)
> > +
> > +static inline int
> > +futex_wait (int *futexp, int val)
> > +{
> > +#ifdef __NR_futex
> > +  return syscall (__NR_futex, futexp, FUTEX_WAIT, val);
> > +#else
> > +  return syscall (__NR_futex_time64, futexp, FUTEX_WAIT, val);
> > +#endif
> > +}
> > +
> > +static int
> > +do_test (void)
> > +{
> > +  char st[1024] __attribute__ ((aligned));
> > +  int clone_flags = CLONE_THREAD;
> > +  /* Minimum required flags to used along with CLONE_THREAD.  */
> > +  clone_flags |= CLONE_VM | CLONE_SIGHAND;
> > +  /* We will used ctid to call on futex to wait for thread exit.  */
> > +  clone_flags |= CLONE_CHILD_CLEARTID;
> > +  /* Initialize with a known value.  ctid is set to zero by the kernel after the
> > +     cloned thread has exited.  */
> > +#define CTID_INIT_VAL 1
> > +  pid_t ctid = CTID_INIT_VAL;
> > +  pid_t tid;
> > +
> > +  struct clone_args clone_args =
> > +    {
> > +      .flags = clone_flags & ~CSIGNAL,
> > +      .exit_signal = clone_flags & CSIGNAL,
> > +      .stack = (uintptr_t) st,
> > +      .stack_size = sizeof (st),
> > +      .child_tid = (uintptr_t) &ctid,
> > +    };
> > +  tid = __clone_internal (&clone_args, f, NULL);
> > +  if (tid == -1)
> > +    FAIL_EXIT1 ("clone failed: %m");
> > +
> > +  wait_tid (&ctid, CTID_INIT_VAL);
> > +
> > +  return 2;
> > +}
> > +
> > +#define EXPECTED_STATUS 2
> > +#include <support/test-driver.c>
> > diff --git a/sysdeps/unix/sysv/linux/tst-getpid1-internal.c b/sysdeps/unix/sysv/linux/tst-getpid1-internal.c
> > new file mode 100644
> > index 0000000000..ee69e52401
> > --- /dev/null
> > +++ b/sysdeps/unix/sysv/linux/tst-getpid1-internal.c
> > @@ -0,0 +1,133 @@
> > +/* Verify that the parent pid is unchanged by __clone_internal.
> > +   Copyright (C) 2021 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
> > +   <https://www.gnu.org/licenses/>.  */
> > +
> > +#include <sched.h>
> > +#include <signal.h>
> > +#include <string.h>
> > +#include <stdio.h>
> > +#include <unistd.h>
> > +#include <sys/types.h>
> > +#include <sys/wait.h>
> > +#include <clone_internal.h>
> > +#include <support/xunistd.h>
> > +
> > +#ifndef TEST_CLONE_FLAGS
> > +#define TEST_CLONE_FLAGS 0
> > +#endif
> > +
> > +static int sig;
> > +
> > +static int
> > +f (void *a)
> > +{
> > +  puts ("in f");
> > +  union sigval sival;
> > +  sival.sival_int = getpid ();
> > +  printf ("pid = %d\n", sival.sival_int);
> > +  if (sigqueue (getppid (), sig, sival) != 0)
> > +    return 1;
> > +  return 0;
> > +}
> > +
> > +
> > +static int
> > +do_test (void)
> > +{
> > +  int mypid = getpid ();
> > +
> > +  sig = SIGRTMIN;
> > +  sigset_t ss;
> > +  sigemptyset (&ss);
> > +  sigaddset (&ss, sig);
> > +  if (sigprocmask (SIG_BLOCK, &ss, NULL) != 0)
> > +    {
> > +      printf ("sigprocmask failed: %m\n");
> > +      return 1;
> > +    }
> > +
> > +#ifdef __ia64__
> > +# define STACK_SIZE 256 * 1024
> > +#else
> > +# define STACK_SIZE 128 * 1024
> > +#endif
> > +  char st[STACK_SIZE] __attribute__ ((aligned));
> > +  struct clone_args clone_args =
> > +    {
> > +      .flags = TEST_CLONE_FLAGS & ~CSIGNAL,
> > +      .exit_signal = TEST_CLONE_FLAGS & CSIGNAL,
> > +      .stack = (uintptr_t) st,
> > +      .stack_size = sizeof (st),
> > +    };
> > +  pid_t p = __clone_internal (&clone_args, f, 0);
> > +  if (p == -1)
> > +    {
> > +      printf("clone failed: %m\n");
> > +      return 1;
> > +    }
> > +  printf ("new thread: %d\n", (int) p);
> > +
> > +  siginfo_t si;
> > +  do
> > +    if (sigwaitinfo (&ss, &si) < 0)
> > +      {
> > +     printf("sigwaitinfo failed: %m\n");
> > +     kill (p, SIGKILL);
> > +     return 1;
> > +      }
> > +  while  (si.si_signo != sig || si.si_code != SI_QUEUE);
> > +
> > +  int e;
> > +  xwaitpid (p, &e, __WCLONE);
> > +  if (!WIFEXITED (e))
> > +    {
> > +      if (WIFSIGNALED (e))
> > +     printf ("died from signal %s\n", strsignal (WTERMSIG (e)));
> > +      else
> > +     puts ("did not terminate correctly");
> > +      return 1;
> > +    }
> > +  if (WEXITSTATUS (e) != 0)
> > +    {
> > +      printf ("exit code %d\n", WEXITSTATUS (e));
> > +      return 1;
> > +    }
> > +
> > +  if (si.si_int != (int) p)
> > +    {
> > +      printf ("expected PID %d, got si_int %d\n", (int) p, si.si_int);
> > +      kill (p, SIGKILL);
> > +      return 1;
> > +    }
> > +
> > +  if (si.si_pid != p)
> > +    {
> > +      printf ("expected PID %d, got si_pid %d\n", (int) p, (int) si.si_pid);
> > +      kill (p, SIGKILL);
> > +      return 1;
> > +    }
> > +
> > +  if (getpid () != mypid)
> > +    {
> > +      puts ("my PID changed");
> > +      return 1;
> > +    }
> > +
> > +  return 0;
> > +}
> > +
> > +#include <support/test-driver.c>
>
> Ok.
>
> > diff --git a/sysdeps/unix/sysv/linux/tst-misalign-clone-internal.c b/sysdeps/unix/sysv/linux/tst-misalign-clone-internal.c
> > new file mode 100644
> > index 0000000000..6df5fd2cbc
> > --- /dev/null
> > +++ b/sysdeps/unix/sysv/linux/tst-misalign-clone-internal.c
> > @@ -0,0 +1,86 @@
> > +/* Verify that __clone_internal properly aligns the child stack.
> > +   Copyright (C) 2021 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
> > +   <https://www.gnu.org/licenses/>.  */
> > +
> > +#include <sched.h>
> > +#include <stdbool.h>
> > +#include <stdint.h>
> > +#include <stdio.h>
> > +#include <string.h>
> > +#include <sys/wait.h>
> > +#include <unistd.h>
> > +#include <libc-pointer-arith.h>
> > +#include <tst-stack-align.h>
> > +#include <clone_internal.h>
> > +#include <support/xunistd.h>
> > +#include <support/check.h>
> > +
> > +static int
> > +check_stack_alignment (void *arg)
> > +{
> > +  bool ok = true;
> > +
> > +  puts ("in f");
> > +
> > +  if (TEST_STACK_ALIGN ())
> > +    ok = false;
> > +
> > +  return ok ? 0 : 1;
> > +}

I made a similar change here.

> > +static int
> > +do_test (void)
> > +{
> > +  puts ("in do_test");
> > +
> > +  if (TEST_STACK_ALIGN ())
> > +    FAIL_EXIT1 ("stack isn't aligned\n");
> > +
> > +#ifdef __ia64__
> > +# define STACK_SIZE (256 * 1024)
> > +#else
> > +# define STACK_SIZE (128 * 1024)
> > +#endif
> > +  char st[STACK_SIZE + 1];
> > +  /* NB: Align child stack to 1 byte.  */
> > +  char *stack = PTR_ALIGN_UP (&st[0], 2) + 1;
> > +  struct clone_args clone_args =
> > +    {
> > +      .stack = (uintptr_t) stack,
> > +      .stack_size = STACK_SIZE,
> > +    };
> > +  pid_t p = __clone_internal (&clone_args, check_stack_alignment, 0);
> > +
> > +  /* Clone must not fail.  */
> > +  TEST_VERIFY_EXIT (p != -1);
> > +
> > +  int e;
> > +  xwaitpid (p, &e, __WCLONE);
> > +  if (!WIFEXITED (e))
> > +    {
> > +      if (WIFSIGNALED (e))
> > +     printf ("died from signal %s\n", strsignal (WTERMSIG (e)));
> > +     FAIL_EXIT1 ("process did not terminate correctly");
> > +    }
> > +
> > +  if (WEXITSTATUS (e) != 0)
> > +    FAIL_EXIT1 ("exit code %d", WEXITSTATUS (e));

Likewise.

> > +  return 0;
> > +}
> > +
> > +#include <support/test-driver.c>
> >

Here is the v9 patch.  OK for master?

Thanks.

-- 
H.J.