xref: /freebsd/lib/libc/csu/libc_start1.c (revision 64584008139f73b07fa7c7979c41780be458b8cc)
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 <errno.h>
32 #include <stdlib.h>
33 #include "libc_private.h"
34 
35 extern void (*__preinit_array_start[])(int, char **, char **) __hidden;
36 extern void (*__preinit_array_end[])(int, char **, char **) __hidden;
37 extern void (*__init_array_start[])(int, char **, char **) __hidden;
38 extern void (*__init_array_end[])(int, char **, char **) __hidden;
39 extern void (*__fini_array_start[])(void) __hidden;
40 extern void (*__fini_array_end[])(void) __hidden;
41 extern void _fini(void) __hidden;
42 extern void _init(void) __hidden;
43 
44 extern int _DYNAMIC;
45 #pragma weak _DYNAMIC
46 
47 #if defined(CRT_IRELOC_RELA)
48 extern const Elf_Rela __rela_iplt_start[] __weak_symbol __hidden;
49 extern const Elf_Rela __rela_iplt_end[] __weak_symbol __hidden;
50 
51 #include "reloc.c"
52 
53 static void
process_irelocs(void)54 process_irelocs(void)
55 {
56 	const Elf_Rela *r;
57 
58 	for (r = &__rela_iplt_start[0]; r < &__rela_iplt_end[0]; r++)
59 		crt1_handle_rela(r);
60 }
61 #elif defined(CRT_IRELOC_REL)
62 extern const Elf_Rel __rel_iplt_start[] __weak_symbol __hidden;
63 extern const Elf_Rel __rel_iplt_end[] __weak_symbol __hidden;
64 
65 #include "reloc.c"
66 
67 static void
process_irelocs(void)68 process_irelocs(void)
69 {
70 	const Elf_Rel *r;
71 
72 	for (r = &__rel_iplt_start[0]; r < &__rel_iplt_end[0]; r++)
73 		crt1_handle_rel(r);
74 }
75 #elif defined(CRT_IRELOC_SUPPRESS)
76 #else
77 #error "Define platform reloc type"
78 #endif
79 
80 #ifndef PIC
81 static void
finalizer(void)82 finalizer(void)
83 {
84 	void (*fn)(void);
85 	size_t array_size, n;
86 
87 	array_size = __fini_array_end - __fini_array_start;
88 	for (n = array_size; n > 0; n--) {
89 		fn = __fini_array_start[n - 1];
90 		if ((uintptr_t)fn != 0 && (uintptr_t)fn != 1)
91 			(fn)();
92 	}
93 	_fini();
94 }
95 #endif
96 
97 static void
handle_static_init(int argc,char ** argv,char ** env)98 handle_static_init(int argc, char **argv, char **env)
99 {
100 #ifndef PIC
101 	void (*fn)(int, char **, char **);
102 	size_t array_size, n;
103 
104 	if (&_DYNAMIC != NULL)
105 		return;
106 
107 	atexit(finalizer);
108 
109 	array_size = __preinit_array_end - __preinit_array_start;
110 	for (n = 0; n < array_size; n++) {
111 		fn = __preinit_array_start[n];
112 		if ((uintptr_t)fn != 0 && (uintptr_t)fn != 1)
113 			fn(argc, argv, env);
114 	}
115 	_init();
116 	array_size = __init_array_end - __init_array_start;
117 	for (n = 0; n < array_size; n++) {
118 		fn = __init_array_start[n];
119 		if ((uintptr_t)fn != 0 && (uintptr_t)fn != 1)
120 			fn(argc, argv, env);
121 	}
122 #endif
123 }
124 
125 static void
handle_argv(int argc,char * argv[],char ** env)126 handle_argv(int argc, char *argv[], char **env)
127 {
128 	const char *s;
129 
130 	if (environ == NULL)
131 		environ = env;
132 	if (argc > 0 && argv[0] != NULL) {
133 		__progname = argv[0];
134 		for (s = __progname; *s != '\0'; s++) {
135 			if (*s == '/')
136 				__progname = s + 1;
137 		}
138 	}
139 }
140 
141 static void
handle_irelocs(char * env[])142 handle_irelocs(char *env[])
143 {
144 #ifndef CRT_IRELOC_SUPPRESS
145 	const Elf_Auxinfo *aux;
146 
147 	/* Find the auxiliary vector on the stack. */
148 	while (*env++ != 0)	/* Skip over environment, and NULL terminator */
149 		;
150 	aux = (const Elf_Auxinfo *)env;
151 
152 	ifunc_init(aux);
153 	process_irelocs();
154 #else
155 	(void)env;
156 #endif
157 }
158 
159 void
__libc_start1(int argc,char * argv[],char * env[],void (* cleanup)(void),int (* mainX)(int,char * [],char * []))160 __libc_start1(int argc, char *argv[], char *env[], void (*cleanup)(void),
161     int (*mainX)(int, char *[], char *[]))
162 {
163 	handle_argv(argc, argv, env);
164 
165 	if (&_DYNAMIC != NULL) {
166 		atexit(cleanup);
167 	} else {
168 		handle_irelocs(env);
169 		_init_tls();
170 	}
171 
172 	handle_static_init(argc, argv, env);
173 
174 	/*
175 	 * C17 4.3 paragraph 3:
176 	 * The value of errno in the initial thread is zero at program
177 	 * startup.
178 	 */
179 	errno = 0;
180 	exit(mainX(argc, argv, env));
181 }
182 
183 /* XXXKIB _mcleanup and monstartup defs */
184 extern void _mcleanup(void);
185 extern void monstartup(void *, void *);
186 
187 void
__libc_start1_gcrt(int argc,char * argv[],char * env[],void (* cleanup)(void),int (* mainX)(int,char * [],char * []),int * eprolp,int * etextp)188 __libc_start1_gcrt(int argc, char *argv[], char *env[],
189     void (*cleanup)(void), int (*mainX)(int, char *[], char *[]),
190     int *eprolp, int *etextp)
191 {
192 	handle_argv(argc, argv, env);
193 
194 	if (&_DYNAMIC != NULL) {
195 		atexit(cleanup);
196 	} else {
197 		handle_irelocs(env);
198 		_init_tls();
199 	}
200 
201 	atexit(_mcleanup);
202 	monstartup(eprolp, etextp);
203 
204 	handle_static_init(argc, argv, env);
205 	errno = 0;
206 	exit(mainX(argc, argv, env));
207 }
208