1 /*-
2 * SPDX-License-Identifier: BSD-1-Clause
3 *
4 * Copyright 2018 Andrew Turner
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 *
12 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
13 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
14 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
15 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
16 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
17 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
18 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
19 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
20 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
21 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
22 */
23
24 #include <sys/types.h>
25 #include "crt.h"
26
27 typedef void (*crt_func)(void);
28
29 #ifdef HAVE_CTORS
30
31 /*
32 * On some architectures and toolchains we may need to call the .ctors.
33 * These are called in the reverse order they are in the ELF file.
34 */
35 static void __do_global_ctors_aux(void) __used;
36
37 static crt_func __CTOR_END__[] __section(".ctors") __used = {
38 (crt_func)0
39 };
40 static crt_func __DTOR_END__[] __section(".dtors") __used = {
41 (crt_func)0
42 };
43
44 extern const char startof_ctors[] __asm(".startof..ctors")
45 __weak_symbol __hidden;
46
47 static void
__do_global_ctors_aux(void)48 __do_global_ctors_aux(void)
49 {
50 crt_func fn;
51 uintptr_t ctors_start;
52 int n;
53
54 ctors_start = (uintptr_t)&startof_ctors;
55 for (n = 1;; n++) {
56 fn = __CTOR_END__[-n];
57 if (fn == (crt_func)0 || fn == (crt_func)-1 ||
58 (ctors_start > 0 &&
59 (uintptr_t)&__CTOR_END__[-n] < ctors_start))
60 break;
61 fn();
62 }
63 }
64
65 asm (
66 ".pushsection .init \n"
67 "\t" INIT_CALL_SEQ(__do_global_ctors_aux) "\n"
68 ".popsection \n"
69 );
70 #endif
71