vfork.c 1.1 KB

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  1. #include <unistd.h>
  2. #include <sys/types.h>
  3. #include <errno.h>
  4. #include <sys/syscall.h>
  5. libc_hidden_proto(vfork)
  6. #define __syscall_clobbers \
  7. "r4", "r5", "r6", "r7", "r8", "r9", "r10", "r11", "r12"
  8. #define __syscall_return(type) \
  9. return (__sc_err & 0x10000000 ? errno = __sc_ret, __sc_ret = -1 : 0), \
  10. (type) __sc_ret
  11. pid_t vfork(void)
  12. {
  13. unsigned long __sc_ret, __sc_err;
  14. register unsigned long __sc_0 __asm__ ("r0");
  15. register unsigned long __sc_3 __asm__ ("r3");
  16. #if 0
  17. /* Sigh. The vfork system call on powerpc
  18. * seems to be completely broken. So just
  19. * use fork instead */
  20. __sc_0 = __NR_vfork;
  21. __asm__ __volatile__
  22. ("sc \n\t"
  23. "mfcr %1 "
  24. : "=&r" (__sc_3), "=&r" (__sc_0)
  25. : "0" (__sc_3), "1" (__sc_0)
  26. : __syscall_clobbers);
  27. __sc_ret = __sc_3;
  28. __sc_err = __sc_0;
  29. if((__sc_err & 0x10000000) && (__sc_ret == ENOSYS))
  30. #endif
  31. {
  32. __sc_0 = __NR_fork;
  33. __asm__ __volatile__
  34. ("sc \n\t"
  35. "mfcr %1 "
  36. : "=&r" (__sc_3), "=&r" (__sc_0)
  37. : "0" (__sc_3), "1" (__sc_0)
  38. : __syscall_clobbers);
  39. __sc_ret = __sc_3;
  40. __sc_err = __sc_0;
  41. }
  42. __syscall_return (pid_t);
  43. }
  44. libc_hidden_def(vfork)