sysdeps/unix/sysv/linux/m68k/vfork.S

   1 /* Copyright (C) 1999-2018 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3    Contributed by Andreas Schwab <schwab@gnu.org>.
   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    <http://www.gnu.org/licenses/>.  */
  18
  19 #include <sysdep.h>
  20 #define _ERRNO_H        1
  21 #include <bits/errno.h>
  22 #include <tcb-offsets.h>
  23
  24 /* Clone the calling process, but without copying the whole address space.
  25    The calling process is suspended until the new process exits or is
  26    replaced by a call to `execve'.  Return -1 for errors, 0 to the new process,
  27    and the process ID of the new process to the old process.  */
  28
  29 ENTRY (__vfork)
  30
  31         /* Pop the return PC value into A0.  */
  32         movel   %sp@+, %a0
  33         cfi_adjust_cfa_offset (-4)
  34         cfi_register (%pc, %a0)
  35
  36         /* Stuff the syscall number in D0 and trap into the kernel.  */
  37         movel   #SYS_ify (vfork), %d0
  38         trap    #0
  39
  40         tstl    %d0
  41         jmi     .Lerror         /* Branch forward if it failed.  */
  42
  43         /* Jump to the return PC.  */
  44         jmp     %a0@
  45
  46 .Lerror:
  47         /* Push back the return PC.  */
  48         movel   %a0,%sp@-
  49         cfi_adjust_cfa_offset (4)
  50         cfi_rel_offset (%pc, 0)
  51
  52 #ifndef PIC
  53         jbra    SYSCALL_ERROR_LABEL
  54 #endif
  55
  56 PSEUDO_END (__vfork)
  57 libc_hidden_def (__vfork)
  58
  59 weak_alias (__vfork, vfork)
  60 strong_alias (__vfork, __libc_vfork)