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/* Copyright (C) 1996, 1997, 1998, 1999 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Pat Beirne <patb@corelcomputer.com>
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. */
/* 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 <asm/errno.h>
#include <sys/syscall.h>
/* int clone(int (*fn)(void *arg), void *child_stack, int flags, void *arg); */
.text
.globl __clone;
.type __clone,%function
.align 4;
__clone:
@ sanity check args
cmp r0, #0
cmpne r1, #0
moveq r0, #-EINVAL
beq __syscall_error (PLT)
@ insert the args onto the new stack
sub r1, r1, #8
str r3, [r1, #4]
@ save the function pointer as the 0th element
str r0, [r1]
@ do the system call
@ get flags
mov r0, r2
@ new sp is already in r1
swi __NR_clone
movs a1, a1
blt __syscall_error (PLT)
movne pc, lr
@ pick the function arg and call address off the stack and execute
ldr r0, [sp, #4]
mov lr, pc
ldr pc, [sp]
@ and we are done, passing the return value through r0
b _exit (PLT)
__syscall_error:
/* Looks like the syscall choked -- set errno */
ldr r3, .L4
/* Calculate the - of the syscall result, in case we need it */
rsb r2, r0, $0
/* errno = -result */
str r2, [r9,r3]
/* return -1 */
mvn r0, $0
mov pc, lr
.size __clone,.-__clone;
.L4: .word errno
.globl clone;
clone = __clone
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