1 /* Copyright (C) 1996-2015 Free Software Foundation, Inc.
2 This file is part of the GNU C Library.
3 Contributed by Pat Beirne <patb@corelcomputer.com>
5 The GNU C Library is free software; you can redistribute it and/or
6 modify it under the terms of the GNU Lesser General Public
7 License as published by the Free Software Foundation; either
8 version 2.1 of the License, or (at your option) any later version.
10 The GNU C Library is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 Lesser General Public License for more details.
15 You should have received a copy of the GNU Lesser General Public
16 License along with the GNU C Library. If not, see
17 <http://www.gnu.org/licenses/>. */
19 /* clone() is even more special than fork() as it mucks with stacks
20 and invokes a function in the right context after its all over. */
23 #include <tcb-offsets.h>
25 #include <bits/errno.h>
27 #define CLONE_VM 0x00000100
28 #define CLONE_THREAD 0x00010000
30 /* int clone(int (*fn)(void *arg), void *child_stack, int flags, void *arg,
31 pid_t *ptid, struct user_desc *tls, pid_t *ctid); */
40 beq PLTJMP(syscall_error)
42 @ insert the args onto the new stack
50 @ new sp is already in r1
52 cfi_adjust_cfa_offset (8)
53 cfi_rel_offset (r4, 0)
54 cfi_rel_offset (r7, 4)
58 ldr r7, =SYS_ify(clone)
64 blt PLTJMP(C_SYMBOL_NAME(__syscall_error))
78 ldr r7, =SYS_ify(getpid)
82 NEGOFF_ADJ_BASE (r1, TID_OFFSET)
83 str r0, NEGOFF_OFF1 (r1, TID_OFFSET)
84 str r0, NEGOFF_OFF2 (r1, PID_OFFSET, TID_OFFSET)
86 @ pick the function arg and call address off the stack and execute
91 @ and we are done, passing the return value through r0
92 b PLTJMP(HIDDEN_JUMPTARGET(_exit))
96 weak_alias (__clone, clone)