1 /* Copyright (C) 1999-2014 Free Software Foundation, Inc.
2 This file is part of the GNU C Library.
4 The GNU C Library is free software; you can redistribute it and/or
5 modify it under the terms of the GNU Lesser General Public
6 License as published by the Free Software Foundation; either
7 version 2.1 of the License, or (at your option) any later version.
9 The GNU C Library is distributed in the hope that it will be useful,
10 but WITHOUT ANY WARRANTY; without even the implied warranty of
11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 Lesser General Public License for more details.
14 You should have received a copy of the GNU Lesser General Public
15 License along with the GNU C Library; if not, see
16 <http://www.gnu.org/licenses/>. */
18 /* clone() is even more special than fork() as it mucks with stacks
19 and invokes a function in the right context after its all over. */
23 #include <bits/errno.h>
25 #include <tcb-offsets.h>
27 /* int clone(int (*fn)(void *arg), void *child_stack, int flags, void *arg,
28 pid_t *ptid, void *tls, pid_t *ctid); */
32 /* sanity check arguments. */
41 /* insert the args onto the new stack */
43 /* save the function pointer as the 0th element */
46 /* do the system call */
51 mov #+SYS_ify(clone), r3
56 not r1, r1 // r1=0 means r0 = -1 to -4095
57 tst r1, r1 // i.e. error in linux
68 /* terminate the stack frame */
73 tst #1, r0 // CLONE_THREAD = (1 << 16)
78 tst #1, r0 // CLONE_VM = (1 << 8)
81 mov #+SYS_ify(getpid), r3
98 /* we are done, passing the return value through r0 */
120 .long _GLOBAL_OFFSET_TABLE_
122 .long PLTJMP(C_SYMBOL_NAME(_exit))
125 .word PID - TLS_PRE_TCB_SIZE
127 .word TID - TLS_PRE_TCB_SIZE
131 weak_alias (__clone, clone)