xref: /freebsd/lib/libc/csu/libc_start1.c (revision 87bf66d4a7488c496af110d4d05cc0273d49f82e)
1 /*-
2  * SPDX-License-Identifier: BSD-1-Clause
3  *
4  * Copyright 2012 Konstantin Belousov <kib@FreeBSD.org>
5  * Copyright (c) 2018, 2023 The FreeBSD Foundation
6  *
7  * Parts of this software was developed by Konstantin Belousov
8  * <kib@FreeBSD.org> under sponsorship from the FreeBSD Foundation.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
17  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
18  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
19  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
20  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
21  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
22  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
23  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
24  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
25  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26  */
27 
28 #include <sys/param.h>
29 #include <sys/elf.h>
30 #include <sys/elf_common.h>
31 #include <stdlib.h>
32 #include "libc_private.h"
33 
34 extern void (*__preinit_array_start[])(int, char **, char **) __hidden;
35 extern void (*__preinit_array_end[])(int, char **, char **) __hidden;
36 extern void (*__init_array_start[])(int, char **, char **) __hidden;
37 extern void (*__init_array_end[])(int, char **, char **) __hidden;
38 extern void (*__fini_array_start[])(void) __hidden;
39 extern void (*__fini_array_end[])(void) __hidden;
40 extern void _fini(void) __hidden;
41 extern void _init(void) __hidden;
42 
43 extern int _DYNAMIC;
44 #pragma weak _DYNAMIC
45 
46 #if defined(CRT_IRELOC_RELA)
47 extern const Elf_Rela __rela_iplt_start[] __weak_symbol __hidden;
48 extern const Elf_Rela __rela_iplt_end[] __weak_symbol __hidden;
49 
50 #include "reloc.c"
51 
52 static void
53 process_irelocs(void)
54 {
55 	const Elf_Rela *r;
56 
57 	for (r = &__rela_iplt_start[0]; r < &__rela_iplt_end[0]; r++)
58 		crt1_handle_rela(r);
59 }
60 #elif defined(CRT_IRELOC_REL)
61 extern const Elf_Rel __rel_iplt_start[] __weak_symbol __hidden;
62 extern const Elf_Rel __rel_iplt_end[] __weak_symbol __hidden;
63 
64 #include "reloc.c"
65 
66 static void
67 process_irelocs(void)
68 {
69 	const Elf_Rel *r;
70 
71 	for (r = &__rel_iplt_start[0]; r < &__rel_iplt_end[0]; r++)
72 		crt1_handle_rel(r);
73 }
74 #elif defined(CRT_IRELOC_SUPPRESS)
75 #else
76 #error "Define platform reloc type"
77 #endif
78 
79 #ifndef PIC
80 static void
81 finalizer(void)
82 {
83 	void (*fn)(void);
84 	size_t array_size, n;
85 
86 	array_size = __fini_array_end - __fini_array_start;
87 	for (n = array_size; n > 0; n--) {
88 		fn = __fini_array_start[n - 1];
89 		if ((uintptr_t)fn != 0 && (uintptr_t)fn != 1)
90 			(fn)();
91 	}
92 	_fini();
93 }
94 #endif
95 
96 static void
97 handle_static_init(int argc, char **argv, char **env)
98 {
99 #ifndef PIC
100 	void (*fn)(int, char **, char **);
101 	size_t array_size, n;
102 
103 	if (&_DYNAMIC != NULL)
104 		return;
105 
106 	atexit(finalizer);
107 
108 	array_size = __preinit_array_end - __preinit_array_start;
109 	for (n = 0; n < array_size; n++) {
110 		fn = __preinit_array_start[n];
111 		if ((uintptr_t)fn != 0 && (uintptr_t)fn != 1)
112 			fn(argc, argv, env);
113 	}
114 	_init();
115 	array_size = __init_array_end - __init_array_start;
116 	for (n = 0; n < array_size; n++) {
117 		fn = __init_array_start[n];
118 		if ((uintptr_t)fn != 0 && (uintptr_t)fn != 1)
119 			fn(argc, argv, env);
120 	}
121 #endif
122 }
123 
124 static void
125 handle_argv(int argc, char *argv[], char **env)
126 {
127 	const char *s;
128 
129 	if (environ == NULL)
130 		environ = env;
131 	if (argc > 0 && argv[0] != NULL) {
132 		__progname = argv[0];
133 		for (s = __progname; *s != '\0'; s++) {
134 			if (*s == '/')
135 				__progname = s + 1;
136 		}
137 	}
138 }
139 
140 static void
141 handle_irelocs(char *env[])
142 {
143 #ifndef CRT_IRELOC_SUPPRESS
144 	const Elf_Auxinfo *aux;
145 
146 	/* Find the auxiliary vector on the stack. */
147 	while (*env++ != 0)	/* Skip over environment, and NULL terminator */
148 		;
149 	aux = (const Elf_Auxinfo *)env;
150 
151 	ifunc_init(aux);
152 	process_irelocs();
153 #else
154 	(void)env;
155 #endif
156 }
157 
158 void
159 __libc_start1(int argc, char *argv[], char *env[], void (*cleanup)(void),
160     int (*mainX)(int, char *[], char *[]))
161 {
162 	handle_argv(argc, argv, env);
163 
164 	if (&_DYNAMIC != NULL) {
165 		atexit(cleanup);
166 	} else {
167 		handle_irelocs(env);
168 		_init_tls();
169 	}
170 
171 	handle_static_init(argc, argv, env);
172 	exit(mainX(argc, argv, env));
173 }
174 
175 /* XXXKIB _mcleanup and monstartup defs */
176 extern void _mcleanup(void);
177 extern void monstartup(void *, void *);
178 
179 void
180 __libc_start1_gcrt(int argc, char *argv[], char *env[],
181     void (*cleanup)(void), int (*mainX)(int, char *[], char *[]),
182     int *eprolp, int *etextp)
183 {
184 	handle_argv(argc, argv, env);
185 
186 	if (&_DYNAMIC != NULL) {
187 		atexit(cleanup);
188 	} else {
189 		handle_irelocs(env);
190 		_init_tls();
191 	}
192 
193 	atexit(_mcleanup);
194 	monstartup(eprolp, etextp);
195 
196 	handle_static_init(argc, argv, env);
197 	exit(mainX(argc, argv, env));
198 }
199