1/* Copyright (C) 1996-2022 Free Software Foundation, Inc.
2 This file is part of the GNU C Library.
3
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.
8
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.
13
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 <https://www.gnu.org/licenses/>. */
17
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. */
20
21#include <asm/errno.h>
22#include <tcb-offsets.h>
23#include <sysdep.h>
24
25/* int clone(int (*fn)(void *arg), void *child_stack, int flags, void *arg,
26 pid_t *ptid, void *tls, pid_t *ctid); */
27
28 .text
29ENTRY (__clone)
30 save %sp,-96,%sp
31 cfi_def_cfa_register(%fp)
32 cfi_window_save
33 cfi_register(%o7, %i7)
34
35 /* sanity check arguments */
36 orcc %i0,%g0,%g2
37 be .Leinval
38 orcc %i1,%g0,%o1
39 be .Leinval
40 mov %i2,%o0
41
42 /* The child_stack is the top of the stack, allocate one
43 whole stack frame from that as this is what the kernel
44 expects. */
45 sub %o1, 96, %o1
46 mov %i3, %g3
47
48 /* ptid */
49 mov %i4,%o2
50 /* tls */
51 mov %i5,%o3
52 /* ctid */
53 ld [%fp+92],%o4
54
55 /* Do the system call */
56 set __NR_clone,%g1
57 ta 0x10
58 bcs .Lerror
59 tst %o1
60 bne __thread_start
61 nop
62 jmpl %i7 + 8, %g0
63 restore %o0,%g0,%o0
64
65.Leinval:
66 mov EINVAL, %o0
67.Lerror:
68 call HIDDEN_JUMPTARGET(__errno_location)
69 mov %o0, %i0
70 st %i0,[%o0]
71 jmpl %i7 + 8, %g0
72 restore %g0,-1,%o0
73END(__clone)
74
75 .type __thread_start,@function
76__thread_start:
77 mov %g0, %fp /* terminate backtrace */
78 call %g2
79 mov %g3,%o0
80 set __NR_exit, %g1
81 ta 0x10
82 nop
83
84 .size __thread_start, .-__thread_start
85
86libc_hidden_def (__clone)
87weak_alias (__clone, clone)
88

source code of glibc/sysdeps/unix/sysv/linux/sparc/sparc32/clone.S