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/* Copyright (C) 1996-2000,02,03,04,2005 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 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/>. */
/* clone() is even more special than fork() as it mucks with stacks
and invokes a function in the right context after its all over.
Hacked up for uClibc by Erik Andersen <andersen@codepoet.org>
*/
#define _ERRNO_H 1
#include <bits/errno.h>
#include <sys/syscall.h>
/* int clone(int (*fn)(void *arg), void *child_stack, int flags, void *arg,
pid_t *ptid, struct user_desc *tls, pid_t *ctid); */
#define LINKAGE 4
#define PTR_SIZE 4
#define PARMS LINKAGE /* no space for saved regs */
#define FUNC PARMS
#define STACK FUNC+4
#define FLAGS STACK+PTR_SIZE
#define ARG FLAGS+4
#define PTID ARG+PTR_SIZE
#define TLS PTID+PTR_SIZE
#define CTID TLS+PTR_SIZE
.text
.global clone
.type clone,%function
clone:
/* Sanity check arguments. */
movl $-EINVAL,%eax
/* no NULL function pointers */
movl FUNC(%esp),%ecx
#ifdef __PIC__
jecxz __error
#else
testl %ecx,%ecx
jz __error
#endif
/* no NULL stack pointers */
movl STACK(%esp),%ecx
#ifdef __PIC__
jecxz __error
#else
testl %ecx,%ecx
jz __error
#endif
/* Insert the argument onto the new stack. Make sure the new
thread is started with an alignment of (mod 16). */
andl $0xfffffff0, %ecx
subl $28,%ecx
movl ARG(%esp),%eax /* no negative argument counts */
movl %eax,12(%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,8(%ecx)
/* Don't leak any information. */
movl $0,4(%ecx)
/* Do the system call */
pushl %ebx
pushl %esi
pushl %edi
movl TLS+12(%esp),%esi
movl PTID+12(%esp),%edx
movl FLAGS+12(%esp),%ebx
movl CTID+12(%esp),%edi
movl $__NR_clone,%eax
int $0x80
popl %edi
popl %esi
popl %ebx
test %eax,%eax
jl __error
jz .Lthread_start
ret
.Lthread_start:
/* Note: %esi is zero. */
movl %esi,%ebp /* terminate the stack frame */
call *%ebx
#ifdef __PIC__
call .Lhere
.Lhere:
popl %ebx
addl $_GLOBAL_OFFSET_TABLE_+[.-.Lhere], %ebx
#endif
movl %eax, %ebx
movl $__NR_exit, %eax
int $0x80
/* Need to indirect jump to syscall error
* or we end up with TEXTREL's
*/
__error:
jmp __syscall_error
.size clone,.-clone
weak_alias(clone, __clone)
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