1  /* Auxiliary functions to issue the clone syscall.
       2     Copyright (C) 2021-2023 Free Software Foundation, Inc.
       3     This file is part of the GNU C Library.
       4  
       5     The GNU C Library is free software; you can redistribute it and/or
       6     modify it under the terms of the GNU Lesser General Public
       7     License as published by the Free Software Foundation; either
       8     version 2.1 of the License, or (at your option) any later version.
       9  
      10     The GNU C Library is distributed in the hope that it will be useful,
      11     but WITHOUT ANY WARRANTY; without even the implied warranty of
      12     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
      13     Lesser General Public License for more details.
      14  
      15     You should have received a copy of the GNU Lesser General Public
      16     License along with the GNU C Library; if not, see
      17     <https://www.gnu.org/licenses/>.  */
      18  
      19  #ifdef __linux__
      20  # include <support/check.h>
      21  # include <stackinfo.h>  /* For _STACK_GROWS_{UP,DOWN}.  */
      22  # include <xsched.h>
      23  
      24  pid_t
      25  xclone (int (*fn) (void *arg), void *arg, void *stack, size_t stack_size,
      26  	int flags)
      27  {
      28    pid_t r = -1;
      29  
      30  # ifdef __ia64__
      31    extern int __clone2 (int (*fn) (void *arg), void *stack, size_t stack_size,
      32  		       int flags, void *arg, ...);
      33    r = __clone2 (fn, stack, stack_size, flags, arg, /* ptid */ NULL,
      34  		/* tls */ NULL, /* ctid  */ NULL);
      35  # else
      36  #  if _STACK_GROWS_DOWN
      37    r = clone (fn, stack + stack_size, flags, arg, /* ptid */ NULL,
      38  	     /* tls */ NULL, /* ctid */  NULL);
      39  #  elif _STACK_GROWS_UP
      40    r = clone (fn, stack, flags, arg, /* ptid */ NULL, /* tls */ NULL, NULL);
      41  #  endif
      42  # endif
      43  
      44    if (r < 0)
      45      FAIL_EXIT1 ("clone: %m");
      46  
      47    return r;
      48  }
      49  #endif