1/* Special .init and .fini section support for x86-64.
2 Copyright (C) 2012-2021 Free Software Foundation, Inc.
3 This file is part of the GNU C Library.
4
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.
9
10 In addition to the permissions in the GNU Lesser General Public
11 License, the Free Software Foundation gives you unlimited
12 permission to link the compiled version of this file with other
13 programs, and to distribute those programs without any restriction
14 coming from the use of this file. (The GNU Lesser General Public
15 License restrictions do apply in other respects; for example, they
16 cover modification of the file, and distribution when not linked
17 into another program.)
18
19 Note that people who make modified versions of this file are not
20 obligated to grant this special exception for their modified
21 versions; it is their choice whether to do so. The GNU Lesser
22 General Public License gives permission to release a modified
23 version without this exception; this exception also makes it
24 possible to release a modified version which carries forward this
25 exception.
26
27 The GNU C Library is distributed in the hope that it will be useful,
28 but WITHOUT ANY WARRANTY; without even the implied warranty of
29 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
30 Lesser General Public License for more details.
31
32 You should have received a copy of the GNU Lesser General Public
33 License along with the GNU C Library; if not, see
34 <https://www.gnu.org/licenses/>. */
35
36/* crti.S puts a function prologue at the beginning of the .init and
37 .fini sections and defines global symbols for those addresses, so
38 they can be called as functions. The symbols _init and _fini are
39 magic and cause the linker to emit DT_INIT and DT_FINI. */
40
41#include <libc-symbols.h>
42#include <sysdep.h>
43
44#ifndef PREINIT_FUNCTION
45# define PREINIT_FUNCTION __gmon_start__
46#endif
47
48#ifndef PREINIT_FUNCTION_WEAK
49# define PREINIT_FUNCTION_WEAK 1
50#endif
51
52#if PREINIT_FUNCTION_WEAK
53 weak_extern (PREINIT_FUNCTION)
54#else
55 .hidden PREINIT_FUNCTION
56#endif
57
58 .section .init,"ax",@progbits
59 .p2align 2
60 .globl _init
61 .hidden _init
62 .type _init, @function
63_init:
64 _CET_ENDBR
65 /* Maintain 16-byte stack alignment for called functions. */
66 subq $8, %rsp
67#if PREINIT_FUNCTION_WEAK
68 movq PREINIT_FUNCTION@GOTPCREL(%rip), %rax
69 testq %rax, %rax
70 je .Lno_weak_fn
71 call *%rax
72.Lno_weak_fn:
73#else
74 call PREINIT_FUNCTION
75#endif
76
77 .section .fini,"ax",@progbits
78 .p2align 2
79 .globl _fini
80 .hidden _fini
81 .type _fini, @function
82_fini:
83 _CET_ENDBR
84 subq $8, %rsp
85