1/*
2 * Copyright (C) 2013 The Android Open Source Project
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 *  * Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 *  * Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in
12 *    the documentation and/or other materials provided with the
13 *    distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
16 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
17 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
18 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
19 * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
20 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
21 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
22 * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
23 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
24 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
25 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26 * SUCH DAMAGE.
27 */
28
29#include <private/bionic_asm.h>
30
31// pid_t __bionic_clone(int flags, void* child_stack, pid_t* parent_tid, void* tls, pid_t* child_tid, int (*fn)(void*), void* arg);
32
33ENTRY_PRIVATE(__bionic_clone)
34    # Push 'fn' and 'arg' onto the child stack.
35    stp     x5, x6, [x1, #-16]!
36
37    # Make the system call.
38    mov     x8, __NR_clone
39    svc     #0
40
41    # Are we the child?
42    cbz     x0, .L_bc_child
43
44    # Set errno if something went wrong.
45    cmn     x0, #(MAX_ERRNO + 1)
46    cneg    x0, x0, hi
47    b.hi    __set_errno_internal
48
49    ret
50
51.L_bc_child:
52    # We're in the child now. Set the end of the frame record chain.
53    mov     x29, #0
54    # Setting x30 to 0 will make the unwinder stop at __start_thread.
55    mov     x30, #0
56    # Call __start_thread with the 'fn' and 'arg' we stored on the child stack.
57    ldp     x0, x1, [sp], #16
58    b       __start_thread
59END(__bionic_clone)
60
61NOTE_GNU_PROPERTY()
62