1 | /* Special .init and .fini section support for AArch64. |
2 | Copyright (C) 1995-2022 Free Software Foundation, Inc. |
3 | |
4 | This file is part of the GNU C Library. |
5 | |
6 | The GNU C Library is free software; you can redistribute it and/or |
7 | modify it under the terms of the GNU Lesser General Public |
8 | License as published by the Free Software Foundation; either |
9 | version 2.1 of the License, or (at your option) any later version. |
10 | |
11 | In addition to the permissions in the GNU Lesser General Public |
12 | License, the Free Software Foundation gives you unlimited |
13 | permission to link the compiled version of this file with other |
14 | programs, and to distribute those programs without any restriction |
15 | coming from the use of this file. (The GNU Lesser General Public |
16 | License restrictions do apply in other respects; for example, they |
17 | cover modification of the file, and distribution when not linked |
18 | into another program.) |
19 | |
20 | Note that people who make modified versions of this file are not |
21 | obligated to grant this special exception for their modified |
22 | versions; it is their choice whether to do so. The GNU Lesser |
23 | General Public License gives permission to release a modified |
24 | version without this exception; this exception also makes it |
25 | possible to release a modified version which carries forward this |
26 | exception. |
27 | |
28 | The GNU C Library is distributed in the hope that it will be useful, |
29 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
30 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
31 | Lesser General Public License for more details. |
32 | |
33 | You should have received a copy of the GNU Lesser General Public |
34 | License along with the GNU C Library; if not, see |
35 | <https://www.gnu.org/licenses/>. */ |
36 | |
37 | /* crti.S puts a function prologue at the beginning of the .init and |
38 | .fini sections and defines global symbols for those addresses, so |
39 | they can be called as functions. The symbols _init and _fini are |
40 | magic and cause the linker to emit DT_INIT and DT_FINI. */ |
41 | |
42 | #include <sysdep.h> |
43 | #include <libc-symbols.h> |
44 | |
45 | #ifndef PREINIT_FUNCTION |
46 | # define PREINIT_FUNCTION __gmon_start__ |
47 | #endif |
48 | |
49 | #ifndef PREINIT_FUNCTION_WEAK |
50 | # define PREINIT_FUNCTION_WEAK 1 |
51 | #endif |
52 | |
53 | #if PREINIT_FUNCTION_WEAK |
54 | weak_extern (PREINIT_FUNCTION) |
55 | #else |
56 | .hidden PREINIT_FUNCTION |
57 | #endif |
58 | |
59 | #if PREINIT_FUNCTION_WEAK |
60 | .align 2 |
61 | .type call_weak_fn, %function |
62 | call_weak_fn: |
63 | adrp x0, :got:PREINIT_FUNCTION |
64 | ldr PTR_REG (0), [x0, #:got_lo12:PREINIT_FUNCTION] |
65 | cbz x0, 1f |
66 | b PREINIT_FUNCTION |
67 | 1: |
68 | RET |
69 | .size call_weak_fn, .-call_weak_fn |
70 | #endif |
71 | |
72 | .section .init,"ax" ,%progbits |
73 | .align 2 |
74 | .global _init |
75 | .hidden _init |
76 | .type _init, %function |
77 | _init: |
78 | #if HAVE_AARCH64_PAC_RET |
79 | PACIASP |
80 | #else |
81 | BTI_C |
82 | #endif |
83 | stp x29, x30, [sp, -16]! |
84 | mov x29, sp |
85 | #if PREINIT_FUNCTION_WEAK |
86 | bl call_weak_fn |
87 | #else |
88 | bl PREINIT_FUNCTION |
89 | #endif |
90 | |
91 | .section .fini,"ax" ,%progbits |
92 | .align 2 |
93 | .global _fini |
94 | .hidden _fini |
95 | .type _fini, %function |
96 | _fini: |
97 | #if HAVE_AARCH64_PAC_RET |
98 | PACIASP |
99 | #else |
100 | BTI_C |
101 | #endif |
102 | stp x29, x30, [sp, -16]! |
103 | mov x29, sp |
104 | |