vfork.S 1.7 KB

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  1. /* vi: set sw=4 ts=4: */
  2. /* vfork for uClibc
  3. *
  4. * Copyright (C) 2000 by Lineo, inc. and Erik Andersen
  5. * Copyright (C) 2000,2001 by Erik Andersen <andersen@uclibc.org>
  6. * Written by Erik Andersen <andersen@uclibc.org>
  7. *
  8. * This program is free software; you can redistribute it and/or modify it
  9. * under the terms of the GNU Library General Public License as published by
  10. * the Free Software Foundation; either version 2 of the License, or (at your
  11. * option) any later version.
  12. *
  13. * This program is distributed in the hope that it will be useful, but WITHOUT
  14. * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  15. * FITNESS FOR A PARTICULAR PURPOSE. See the GNU Library General Public License
  16. * for more details.
  17. *
  18. * You should have received a copy of the GNU Library General Public License
  19. * along with this program; if not, write to the Free Software Foundation,
  20. * Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  21. */
  22. #include <asm/errno.h>
  23. #include <sys/syscall.h>
  24. .text
  25. .global vfork;
  26. .type vfork,%function
  27. .align 4; \
  28. vfork:
  29. #ifdef __NR_vfork
  30. swi __NR_vfork
  31. cmn r0, #4096
  32. movcc pc, lr
  33. /* Check if vfork even exists. */
  34. ldr r1, =-ENOSYS
  35. teq r0, r1
  36. bne __syscall_error
  37. #endif
  38. /* If we don't have vfork, use fork. */
  39. swi __NR_fork
  40. cmn r0, #4096
  41. /* Syscal worked. Return to child/parent */
  42. movcc pc, lr
  43. __syscall_error:
  44. /* Looks like the syscall choked -- set errno */
  45. ldr r3, .L4
  46. /* Calculate the - of the syscall result, in case we need it */
  47. rsb r2, r0, $0
  48. /* errno = -result */
  49. str r2, [r9,r3]
  50. /* return -1 */
  51. mvn r0, $0
  52. mov pc, lr
  53. .L4: .word errno