/* Test if CLONE_VM does not change pthread pid/tid field (BZ #19957)
   Copyright (C) 2021-2026 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");

#define STACK_SIZE 128 * 1024
  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]);

  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);
  TEST_VERIFY (WIFEXITED (e));
  TEST_COMPARE (WEXITSTATUS (e), 0);
  return 0;
}

#include <support/test-driver.c>
