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/* Copyright (C) 1996, 1997, 1998, 1999, 2000 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Richard Henderson (rth@tamu.edu)
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Library General Public License as
published by the Free Software Foundation; either version 2 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
Library General Public License for more details.
You should have received a copy of the GNU Library General Public
License along with the GNU C Library; see the file COPYING.LIB. If not,
write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
Boston, MA 02111-1307, USA. */
/* clone() is even more special than fork() as it mucks with stacks
and invokes a function in the right context after its all over. */
#include <sysdep.h>
#define _ERRNO_H 1
#include <bits/errno.h>
#include <asm-syntax.h>
#include <bp-sym.h>
#include <bp-asm.h>
/* int clone(int (*fn)(void *arg), void *child_stack, int flags, void *arg); */
#define PARMS LINKAGE /* no space for saved regs */
#define FUNC PARMS
#define STACK FUNC+4
#define FLAGS STACK+PTR_SIZE
#define ARG FLAGS+4
.text
ENTRY (BP_SYM (__clone))
/* Sanity check arguments. */
movl $-EINVAL,%eax
movl FUNC(%esp),%ecx /* no NULL function pointers */
#ifdef PIC
jecxz SYSCALL_ERROR_LABEL
#else
testl %ecx,%ecx
jz SYSCALL_ERROR_LABEL
#endif
movl STACK(%esp),%ecx /* no NULL stack pointers */
#ifdef PIC
jecxz SYSCALL_ERROR_LABEL
#else
testl %ecx,%ecx
jz SYSCALL_ERROR_LABEL
#endif
/* Insert the argument onto the new stack. */
subl $8,%ecx
movl ARG(%esp),%eax /* no negative argument counts */
movl %eax,4(%ecx)
/* Save the function pointer as the zeroth argument.
It will be popped off in the child in the ebx frobbing below. */
movl FUNC(%esp),%eax
movl %eax,0(%ecx)
/* Do the system call */
pushl %ebx
movl FLAGS+4(%esp),%ebx
movl $SYS_ify(clone),%eax
int $0x80
popl %ebx
test %eax,%eax
jl SYSCALL_ERROR_LABEL
jz thread_start
L(pseudo_end):
ret
thread_start:
subl %ebp,%ebp /* terminate the stack frame */
call *%ebx
#ifdef PIC
call L(here)
L(here):
popl %ebx
addl $_GLOBAL_OFFSET_TABLE_+[.-L(here)], %ebx
#endif
pushl %eax
call JUMPTARGET (_exit)
PSEUDO_END (BP_SYM (__clone))
weak_alias (BP_SYM (__clone), BP_SYM (clone))
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