vfork.S 2.2 KB

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  1. /* Copyright (C) 1999, 2002, 2003, 2005 Free Software Foundation, Inc.
  2. This file is part of the GNU C Library.
  3. Contributed by Philip Blundell <philb@gnu.org>.
  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. The GNU C Library is distributed in the hope that it will be useful,
  9. but WITHOUT ANY WARRANTY; without even the implied warranty of
  10. MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  11. Lesser General Public License for more details.
  12. You should have received a copy of the GNU Lesser General Public
  13. License along with the GNU C Library; if not, write to the Free
  14. Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  15. 02111-1307 USA. */
  16. #include <sysdep-cancel.h>
  17. #define _ERRNO_H 1
  18. #include <bits/errno.h>
  19. #include <kernel-features.h>
  20. /* Clone the calling process, but without copying the whole address space.
  21. The calling process is suspended until the new process exits or is
  22. replaced by a call to `execve'. Return -1 for errors, 0 to the new process,
  23. and the process ID of the new process to the old process. */
  24. ENTRY (__vfork)
  25. #ifdef __NR_vfork
  26. #ifdef SHARED
  27. ldr ip, 1f
  28. ldr r0, 2f
  29. 3: add ip, pc, ip
  30. ldr r0, [ip, r0]
  31. #else
  32. ldr r0, 1f
  33. #endif
  34. movs r0, r0
  35. bne HIDDEN_JUMPTARGET (fork)
  36. DO_CALL (vfork, 0)
  37. cmn a1, #4096
  38. RETINSTR(cc, lr)
  39. #ifndef __ASSUME_VFORK_SYSCALL
  40. /* Check if vfork syscall is known at all. */
  41. cmn a1, #ENOSYS
  42. bne PLTJMP(C_SYMBOL_NAME(__syscall_error))
  43. #endif
  44. #endif
  45. #ifndef __ASSUME_VFORK_SYSCALL
  46. /* If we don't have vfork, fork is close enough. */
  47. DO_CALL (fork, 0)
  48. cmn a1, #4096
  49. RETINSTR(cc, lr)
  50. #elif !defined __NR_vfork
  51. # error "__NR_vfork not available and __ASSUME_VFORK_SYSCALL defined"
  52. #endif
  53. b PLTJMP(C_SYMBOL_NAME(__syscall_error))
  54. #ifdef SHARED
  55. 1: .word _GLOBAL_OFFSET_TABLE_ - 3b - 8
  56. 2: .word __libc_pthread_functions(GOTOFF)
  57. #else
  58. .weak pthread_create
  59. 1: .word pthread_create
  60. #endif
  61. PSEUDO_END (__vfork)
  62. libc_hidden_def (__vfork)
  63. weak_alias (__vfork, vfork)