vfork.S 1.8 KB

1234567891011121314151617181920212223242526272829303132333435363738394041424344454647484950515253545556575859606162636465666768697071
  1. /* Copyright (C) 2004 Free Software Foundation, Inc.
  2. This file is part of the GNU C Library.
  3. The GNU C Library is free software; you can redistribute it and/or
  4. modify it under the terms of the GNU Lesser General Public
  5. License as published by the Free Software Foundation; either
  6. version 2.1 of the License, or (at your option) any later version.
  7. The GNU C Library is distributed in the hope that it will be useful,
  8. but WITHOUT ANY WARRANTY; without even the implied warranty of
  9. MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  10. Lesser General Public License for more details.
  11. You should have received a copy of the GNU Lesser General Public
  12. License along with the GNU C Library; if not, write to the Free
  13. Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  14. 02111-1307 USA. */
  15. #include <sysdep.h>
  16. #define _ERRNO_H 1
  17. #include <bits/errno.h>
  18. #include <tcb-offsets.h>
  19. /* Clone the calling process, but without copying the whole address space.
  20. The calling process is suspended until the new process exits or is
  21. replaced by a call to `execve'. Return -1 for errors, 0 to the new process,
  22. and the process ID of the new process to the old process. */
  23. ENTRY (__vfork)
  24. /* Save the PID value. */
  25. stc gbr, r2
  26. mov.w .L2, r0
  27. mov.l @(r0,r2), r4
  28. neg r4, r1
  29. tst r1, r1
  30. bf 1f
  31. mov #1, r1
  32. rotr r1
  33. 1:
  34. mov.l r1, @(r0,r2)
  35. mov.w .L1, r3
  36. trapa #0x10
  37. mov r0, r1
  38. /* Restore the old PID value in the parent. */
  39. tst r0, r0
  40. bt.s 2f
  41. stc gbr, r2
  42. mov.w .L2, r0
  43. mov.l r4, @(r0,r2)
  44. mov r1, r0
  45. 2:
  46. mov #-12, r2
  47. shad r2, r1
  48. not r1, r1 // r1=0 means r0 = -1 to -4095
  49. tst r1, r1 // i.e. error in linux
  50. bf .Lpseudo_end
  51. SYSCALL_ERROR_HANDLER
  52. .Lpseudo_end:
  53. rts
  54. nop
  55. .L1:
  56. .word __NR_vfork
  57. .L2:
  58. .word PID - TLS_PRE_TCB_SIZE
  59. .align 2
  60. PSEUDO_END (__vfork)
  61. hidden_def (vfork)
  62. weak_alias (__vfork, vfork)