diff options
Diffstat (limited to 'libpthread/linuxthreads/sysdeps/unix/sysv/linux/x86_64/vfork.S')
| -rw-r--r-- | libpthread/linuxthreads/sysdeps/unix/sysv/linux/x86_64/vfork.S | 61 |
1 files changed, 61 insertions, 0 deletions
diff --git a/libpthread/linuxthreads/sysdeps/unix/sysv/linux/x86_64/vfork.S b/libpthread/linuxthreads/sysdeps/unix/sysv/linux/x86_64/vfork.S new file mode 100644 index 000000000..1a58077c4 --- /dev/null +++ b/libpthread/linuxthreads/sysdeps/unix/sysv/linux/x86_64/vfork.S @@ -0,0 +1,61 @@ +/* Copyright (C) 2001, 2002, 2003, 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, see + <http://www.gnu.org/licenses/>. */ + +#include <sysdep-cancel.h> +#define _ERRNO_H 1 +#include <bits/errno.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. */ + +ENTRY (__vfork) + +#ifdef SHARED + cmpq $0, __libc_pthread_functions(%rip) +#else + .weak pthread_create + movq $pthread_create, %rax + testq %rax, %rax +#endif + jne HIDDEN_JUMPTARGET (fork) + + /* 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 + cfi_adjust_cfa_offset(-8) + + /* Stuff the syscall number in RAX and enter into the kernel. */ + movl $SYS_ify (vfork), %eax + syscall + + /* Push back the return PC. */ + pushq %rdi + cfi_adjust_cfa_offset(8) + + cmpl $-4095, %eax + jae SYSCALL_ERROR_LABEL /* Branch forward if it failed. */ + + /* Normal return. */ +.Lpseudo_end: + ret + +PSEUDO_END (__vfork) +libc_hidden_def (__vfork) + +weak_alias (__vfork, vfork) |