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

   1 /* Copyright (C) 1999, 2000, 2002, 2003 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3
   4    The GNU C Library is free software; you can redistribute it and/or
   5    modify it under the terms of the GNU Lesser General Public
   6    License as published by the Free Software Foundation; either
   7    version 2.1 of the License, or (at your option) any later version.
   8
   9    The GNU C Library is distributed in the hope that it will be useful,
  10    but WITHOUT ANY WARRANTY; without even the implied warranty of
  11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12    Lesser General Public License for more details.
  13
  14    You should have received a copy of the GNU Lesser General Public
  15    License along with the GNU C Library; if not, write to the Free
  16    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  17    02111-1307 USA.  */
  18
  19 #include <sysdep.h>
  20 #define _ERRNO_H        1
  21 #include <bits/errno.h>
  22
  23 /* Clone the calling process, but without copying the whole address space.
  24    The calling process is suspended until the new process exits or is
  25    replaced by a call to `execve'.  Return -1 for errors, 0 to the new process,
  26    and the process ID of the new process to the old process.  */
  27
  28 ENTRY (__vfork)
  29
  30 #ifdef __NR_vfork
  31         mov.w   .L3, r3
  32         trapa   #0x10
  33         mov     r0, r1
  34         mov     #-12, r2
  35         shad    r2, r1
  36         not     r1, r1                  // r1=0 means r0 = -1 to -4095
  37         tst     r1, r1                  // i.e. error in linux
  38         bf      1f
  39         mov.w   .L1, r1
  40         cmp/eq  r1, r0
  41         bt      2f
  42         bra     .Lsyscall_error
  43          nop
  44 .L1:
  45         .word   -ENOSYS
  46 .L3:    .word   __NR_vfork
  47 1:
  48         rts
  49          nop
  50 2:
  51 #endif
  52
  53         /* If we don't have vfork, fork is close enough.  */
  54         mov     #+__NR_fork, r3
  55         trapa   #0x10
  56         mov     r0, r1
  57         mov     #-12, r2
  58         shad    r2, r1
  59         not     r1, r1                  // r1=0 means r0 = -1 to -4095
  60         tst     r1, r1                  // i.e. error in linux
  61         bf      .Lpseudo_end
  62 .Lsyscall_error:
  63         SYSCALL_ERROR_HANDLER
  64 .Lpseudo_end:
  65         rts
  66          nop
  67
  68 PSEUDO_END (__vfork)
  69 libc_hidden_def (__vfork)
  70
  71 weak_alias (__vfork, vfork)