pt-vfork.S 1.7 KB

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  1. /* Copyright (C) 2003, 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, see
  13. <http://www.gnu.org/licenses/>. */
  14. #include <sysdep.h>
  15. #define _ERRNO_H 1
  16. #include <bits/errno.h>
  17. #include <tcb-offsets.h>
  18. /* Clone the calling process, but without copying the whole address space.
  19. The calling process is suspended until the new process exits or is
  20. replaced by a call to `execve'. Return -1 for errors, 0 to the new process,
  21. and the process ID of the new process to the old process. */
  22. ENTRY (__vfork)
  23. /* Save the PID value. */
  24. stc gbr, r2
  25. mov.w .L2, r0
  26. mov.l @(r0,r2), r4
  27. neg r4, r1
  28. mov.l r1, @(r0,r2)
  29. mov.w .L1, r3
  30. trapa #0x10
  31. mov r0, r1
  32. /* Restore the old PID value in the parent. */
  33. tst r0, r0
  34. bt/s 2f
  35. stc gbr, r2
  36. mov.w .L2, r0
  37. mov.l r4, @(r0,r2)
  38. mov r1, r0
  39. 2:
  40. mov #-12, r2
  41. shad r2, r1
  42. not r1, r1 // r1=0 means r0 = -1 to -4095
  43. tst r1, r1 // i.e. error in linux
  44. bf .Lpseudo_end
  45. SYSCALL_ERROR_HANDLER
  46. .Lpseudo_end:
  47. rts
  48. nop
  49. .L1:
  50. .word __NR_vfork
  51. .L2:
  52. .word PID - TLS_PRE_TCB_SIZE
  53. PSEUDO_END (__vfork)
  54. weak_alias (__vfork, vfork)