/* 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) #ifndef RESET_PID movl $0,(%ecx) #endif /* 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 #ifdef RESET_PID /* Remember the flag value. */ movl %ebx, (%ecx) #endif 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)