1/*        $NetBSD: __clone.S,v 1.7 2025/05/03 19:55:32 riastradh Exp $          */
2
3/*
4 * Copyright (c) 2001 Wasabi Systems, Inc.
5 * All rights reserved.
6 *
7 * Written by Frank van der Linden for Wasabi Systems, Inc.
8 *
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
11 * are met:
12 * 1. Redistributions of source code must retain the above copyright
13 *    notice, this list of conditions and the following disclaimer.
14 * 2. Redistributions in binary form must reproduce the above copyright
15 *    notice, this list of conditions and the following disclaimer in the
16 *    documentation and/or other materials provided with the distribution.
17 * 3. All advertising materials mentioning features or use of this software
18 *    must display the following acknowledgement:
19 *      This product includes software developed for the NetBSD Project by
20 *      Wasabi Systems, Inc.
21 * 4. The name of Wasabi Systems, Inc. may not be used to endorse
22 *    or promote products derived from this software without specific prior
23 *    written permission.
24 *
25 * THIS SOFTWARE IS PROVIDED BY WASABI SYSTEMS, INC. ``AS IS'' AND
26 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
27 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
28 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL WASABI SYSTEMS, INC
29 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
30 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
31 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
32 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
33 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
34 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
35 * POSSIBILITY OF SUCH DAMAGE.
36 */
37
38#include <machine/asm.h>
39#include <sys/errno.h>
40#include "SYS.h"
41
42#ifdef WEAK_ALIAS
43WEAK_ALIAS(clone, __clone)
44#endif
45          .text
46
47/*
48 * int clone(int (*fn)(void *), void *stack, int flags, void *arg);
49 */
50ENTRY(__clone)
51          pushl     %ebp
52
53          /*
54           * Sanity checks: func and stack may not be NULL.
55           */
56          movl      8(%esp), %ebp
57          cmpl      $0,%ebp             /* function */
58          je        3f
59          movl      12(%esp),%eax       /* stack */
60          cmpl      $0,%eax
61          je        3f
62
63          /*
64           * Set up the stack for the clone.
65           */
66          movl      20(%esp),%ecx
67          movl      %ecx,-4(%eax)       /* argument */
68          leal      -4(%eax),%eax       /* sp points to arg */
69
70          pushl     %eax                /* stack */
71          pushl     20(%esp)  /* flags */
72          pushl     $0                  /* dummy return address */
73
74          SYSTRAP(__clone)
75          jc        4f
76          cmpl      $0,%eax
77          jne       2f                  /* we're the parent */
78          call      *%ebp               /* this is the clone, call the function */
79
80          PIC_PROLOGUE
81          pushl     %eax                /* clone does _exit(func(arg)); */
82          call      PIC_PLT(_C_LABEL(_exit))
83          addl      $4,%esp
84          PIC_EPILOGUE
85
862:
87          addl      $12,%esp
88          popl      %ebp
89          ret
903:
91          movl      $EINVAL,%eax
92          jmp       5f
934:
94          addl      $12,%esp
955:
96          popl      %ebp
97          jmp       CERROR
98END(__clone)
99