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- /* Copyright (C) 2001, 2002, 2004 Free Software Foundation, Inc.
- This file is part of the GNU C Library.
- The GNU C Library is free software; you can redistribute it and/or
- modify it under the terms of the GNU Lesser General Public
- License as published by the Free Software Foundation; either
- version 2.1 of the License, or (at your option) any later version.
- The GNU C Library is distributed in the hope that it will be useful,
- but WITHOUT ANY WARRANTY; without even the implied warranty of
- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
- Lesser General Public License for more details.
- You should have received a copy of the GNU Lesser General Public
- License along with the GNU C Library; if not, write to the Free
- Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
- 02111-1307 USA. */
- #include <sys/syscall.h>
- /* Clone the calling process, but without copying the whole address space.
- The calling process is suspended until the new process exits or is
- replaced by a call to `execve'. Return -1 for errors, 0 to the new process,
- and the process ID of the new process to the old process. */
- #ifndef __NR_vfork
- /* No vfork so use fork instead */
- .weak vfork
- vfork = __libc_fork
- #else
- .text
- .global __vfork
- .type __vfork,%function
- .align 16
- __vfork:
- /* Pop the return PC value into RDI. We need a register that
- is preserved by the syscall and that we're allowed to destroy. */
- popq %rdi
- /* Stuff the syscall number in RAX and enter into the kernel. */
- movl $__NR_vfork, %eax
- syscall
- /* Push back the return PC. */
- pushq %rdi
- cmpl $-4095, %eax
- jae __error /* Branch forward if it failed. */
- /* Normal return. */
- ret
- __error:
- jmp __syscall_error
- .size __vfork,.-__vfork
- .weak vfork
- vfork = __vfork
- #endif /* __NR_vfork */
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