diff mbox series

[v5,5/5] Add tests for __clone_internal

Message ID 20210515123442.1432385-6-hjl.tools@gmail.com
State Superseded
Headers show
Series Add an internal wrapper for clone, clone2 and clone3 | expand

Checks

Context Check Description
dj/TryBot-apply_patch success Patch applied to master at the time it was sent

Commit Message

H.J. Lu May 15, 2021, 12:34 p.m. UTC
These tests should be removed if __clone_internal is no longer exported.
---
 sysdeps/unix/sysv/linux/Makefile              |   7 +-
 .../sysv/linux/tst-align-clone-internal.c     |  91 +++++++++++
 sysdeps/unix/sysv/linux/tst-clone-internal.c  |  51 +++++++
 sysdeps/unix/sysv/linux/tst-clone2-internal.c | 142 ++++++++++++++++++
 sysdeps/unix/sysv/linux/tst-clone3-internal.c | 101 +++++++++++++
 .../unix/sysv/linux/tst-getpid1-internal.c    | 137 +++++++++++++++++
 6 files changed, 528 insertions(+), 1 deletion(-)
 create mode 100644 sysdeps/unix/sysv/linux/tst-align-clone-internal.c
 create mode 100644 sysdeps/unix/sysv/linux/tst-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

Comments

Florian Weimer May 20, 2021, 3:08 p.m. UTC | #1
* H. J. Lu:

> 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..eccc39e255
> --- /dev/null
> +++ b/sysdeps/unix/sysv/linux/tst-align-clone-internal.c

> +  int e;
> +  if (waitpid (p, &e, __WCLONE) != p)
> +    {
> +      puts ("waitpid failed");
> +      kill (p, SIGKILL);
> +      return 1;
> +    }

This could use xwaitpid.  The same comment applies to other tests.

> diff --git a/sysdeps/unix/sysv/linux/tst-clone-internal.c b/sysdeps/unix/sysv/linux/tst-clone-internal.c
> new file mode 100644
> index 0000000000..587d519bf2
> --- /dev/null
> +++ b/sysdeps/unix/sysv/linux/tst-clone-internal.c

> +static int
> +do_test (void)
> +{
> +  int result;
> +
> +  result = __clone_internal (NULL, child_fn, NULL);
> +
> +  if (errno != EINVAL || result != -1)
> +    {
> +      printf ("FAIL: clone()=%d (wanted -1) errno=%d (wanted %d)\n",
> +              result, errno, EINVAL);
> +      return 1;
> +    }
> +
> +  puts ("All OK");
> +  return 0;
> +}

I think this test is invalid for the internal function (the comment
about not checking arguments).

> 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..dd8f32c24b
> --- /dev/null
> +++ b/sysdeps/unix/sysv/linux/tst-clone2-internal.c
> @@ -0,0 +1,142 @@

> +
> +static int
> +f (void *a)
> +{
> +  close (pipefd[0]);
> +
> +  pid_t ppid = getppid ();
> +  pid_t pid = getpid ();
> +  pid_t tid = syscall (__NR_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;
> +}

You could use support_shared_allocate for the parent/child communication
instead of a pipe.  The MAP_SHARED mapping overrides the lack of
CLONE_VM.

> +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");

You could use xpthread_sigmask.  (Applies to tst-getpid1-internal.c as
well.)


> +  pid_t own_pid = getpid ();
> +  pid_t own_tid = syscall (__NR_gettid);

We have gettid nowadays.

> +#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..61863e1504
> --- /dev/null
> +++ b/sysdeps/unix/sysv/linux/tst-clone3-internal.c
> +#include <stackinfo.h>  /* For _STACK_GROWS_{UP,DOWN}.  */

No longer needed! 8-)

> +#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.  */

Missing ).

The rest looks okay as far as I can tell.

Thanks,
Florian
H.J. Lu May 22, 2021, 1:54 a.m. UTC | #2
On Thu, May 20, 2021 at 8:08 AM Florian Weimer <fweimer@redhat.com> wrote:
>
> * H. J. Lu:
>
> > 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..eccc39e255
> > --- /dev/null
> > +++ b/sysdeps/unix/sysv/linux/tst-align-clone-internal.c
>
> > +  int e;
> > +  if (waitpid (p, &e, __WCLONE) != p)
> > +    {
> > +      puts ("waitpid failed");
> > +      kill (p, SIGKILL);
> > +      return 1;
> > +    }
>
> This could use xwaitpid.  The same comment applies to other tests.

Fixed.

> > diff --git a/sysdeps/unix/sysv/linux/tst-clone-internal.c b/sysdeps/unix/sysv/linux/tst-clone-internal.c
> > new file mode 100644
> > index 0000000000..587d519bf2
> > --- /dev/null
> > +++ b/sysdeps/unix/sysv/linux/tst-clone-internal.c
>
> > +static int
> > +do_test (void)
> > +{
> > +  int result;
> > +
> > +  result = __clone_internal (NULL, child_fn, NULL);
> > +
> > +  if (errno != EINVAL || result != -1)
> > +    {
> > +      printf ("FAIL: clone()=%d (wanted -1) errno=%d (wanted %d)\n",
> > +              result, errno, EINVAL);
> > +      return 1;
> > +    }
> > +
> > +  puts ("All OK");
> > +  return 0;
> > +}
>
> I think this test is invalid for the internal function (the comment
> about not checking arguments).

Removed.

> > 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..dd8f32c24b
> > --- /dev/null
> > +++ b/sysdeps/unix/sysv/linux/tst-clone2-internal.c
> > @@ -0,0 +1,142 @@
>
> > +
> > +static int
> > +f (void *a)
> > +{
> > +  close (pipefd[0]);
> > +
> > +  pid_t ppid = getppid ();
> > +  pid_t pid = getpid ();
> > +  pid_t tid = syscall (__NR_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;
> > +}
>
> You could use support_shared_allocate for the parent/child communication
> instead of a pipe.  The MAP_SHARED mapping overrides the lack of
> CLONE_VM.
>
> > +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");
>
> You could use xpthread_sigmask.  (Applies to tst-getpid1-internal.c as
> well.)

Since this test is copied from the previous test and doesn't use
thread, I'd like to keep it this way.

>
> > +  pid_t own_pid = getpid ();
> > +  pid_t own_tid = syscall (__NR_gettid);
>
> We have gettid nowadays.

Fixed.

> > +#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..61863e1504
> > --- /dev/null
> > +++ b/sysdeps/unix/sysv/linux/tst-clone3-internal.c
> > +#include <stackinfo.h>  /* For _STACK_GROWS_{UP,DOWN}.  */
>
> No longer needed! 8-)

Fixed.

> > +#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.  */
>
> Missing ).

Fixed.

> The rest looks okay as far as I can tell.
>
> Thanks,
> Florian
>

Thanks.
diff mbox series

Patch

diff --git a/sysdeps/unix/sysv/linux/Makefile b/sysdeps/unix/sysv/linux/Makefile
index 7c1f32b84d..08a7ec7928 100644
--- a/sysdeps/unix/sysv/linux/Makefile
+++ b/sysdeps/unix/sysv/linux/Makefile
@@ -118,7 +118,12 @@  ifeq ($(have-GLIBC_2.27)$(build-shared),yesyes)
 tests += tst-ofdlocks-compat
 endif
 
-tests-internal += tst-sigcontext-get_pc
+tests-internal += tst-sigcontext-get_pc \
+  tst-align-clone-internal \
+  tst-clone-internal \
+  tst-clone2-internal \
+  tst-clone3-internal \
+  tst-getpid1-internal
 
 CFLAGS-tst-sigcontext-get_pc.c = -fasynchronous-unwind-tables
 
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..eccc39e255
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/tst-align-clone-internal.c
@@ -0,0 +1,91 @@ 
+/* 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 <stackinfo.h>
+#include <clone_internal.h>
+
+static int
+f (void *arg)
+{
+  bool ok = true;
+
+  puts ("in f");
+
+  if (TEST_STACK_ALIGN ())
+    ok = false;
+
+  return ok ? 0 : 1;
+}
+
+static int
+do_test (void)
+{
+  bool ok = true;
+
+  puts ("in main");
+
+  if (TEST_STACK_ALIGN ())
+    ok = false;
+
+#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;
+    }
+
+  int e;
+  if (waitpid (p, &e, __WCLONE) != p)
+    {
+      puts ("waitpid failed");
+      kill (p, SIGKILL);
+      return 1;
+    }
+  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;
+
+  return ok ? 0 : 1;
+}
+
+#include <support/test-driver.c>
diff --git a/sysdeps/unix/sysv/linux/tst-clone-internal.c b/sysdeps/unix/sysv/linux/tst-clone-internal.c
new file mode 100644
index 0000000000..587d519bf2
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/tst-clone-internal.c
@@ -0,0 +1,51 @@ 
+/* Test for proper error/errno handling in clone.
+   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/>.  */
+
+/* BZ #2386 */
+#include <errno.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <sched.h>
+#include <clone_internal.h>
+
+int child_fn(void *arg)
+{
+  puts ("FAIL: in child_fn(); should not be here");
+  exit(1);
+}
+
+static int
+do_test (void)
+{
+  int result;
+
+  result = __clone_internal (NULL, child_fn, NULL);
+
+  if (errno != EINVAL || result != -1)
+    {
+      printf ("FAIL: clone()=%d (wanted -1) errno=%d (wanted %d)\n",
+              result, errno, EINVAL);
+      return 1;
+    }
+
+  puts ("All OK");
+  return 0;
+}
+
+#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..dd8f32c24b
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/tst-clone2-internal.c
@@ -0,0 +1,142 @@ 
+/* 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 <stackinfo.h>  /* For _STACK_GROWS_{UP,DOWN}.  */
+#include <clone_internal.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 = syscall (__NR_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;
+  if (waitpid (p, &e, __WCLONE) != p)
+    {
+      kill (p, SIGKILL);
+      FAIL_EXIT1 ("waitpid failed");
+    }
+  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));
+
+  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..61863e1504
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/tst-clone3-internal.c
@@ -0,0 +1,101 @@ 
+/* 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 <stackinfo.h>  /* For _STACK_GROWS_{UP,DOWN}.  */
+#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..1d1109b188
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/tst-getpid1-internal.c
@@ -0,0 +1,137 @@ 
+/* 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 <stackinfo.h>
+#include <clone_internal.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;
+  if (waitpid (p, &e, __WCLONE) != p)
+    {
+      puts ("waitpid failed");
+      kill (p, SIGKILL);
+      return 1;
+    }
+  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>