xref: /minix/lib/csu/common/crt0-common.c (revision ebfedea0)
1 /* $NetBSD: crt0-common.c,v 1.13 2013/01/31 22:24:25 matt Exp $ */
2 
3 /*
4  * Copyright (c) 1998 Christos Zoulas
5  * Copyright (c) 1995 Christopher G. Demetriou
6  * All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  * 3. All advertising materials mentioning features or use of this software
17  *    must display the following acknowledgement:
18  *          This product includes software developed for the
19  *          NetBSD Project.  See http://www.NetBSD.org/ for
20  *          information about NetBSD.
21  * 4. The name of the author may not be used to endorse or promote products
22  *    derived from this software without specific prior written permission.
23  *
24  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
25  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
26  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
27  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
28  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
29  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
30  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
31  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
32  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
33  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
34  *
35  * <<Id: LICENSE,v 1.2 2000/06/14 15:57:33 cgd Exp>>
36  */
37 
38 #include <sys/cdefs.h>
39 __RCSID("$NetBSD: crt0-common.c,v 1.13 2013/01/31 22:24:25 matt Exp $");
40 
41 #include <sys/types.h>
42 #include <sys/exec.h>
43 #if !defined(__minix)
44 #include <sys/syscall.h>
45 #else
46 #include <string.h>
47 #endif /* !defined(__minix) */
48 #include <machine/profile.h>
49 #include <stdlib.h>
50 #include <unistd.h>
51 
52 #include "rtld.h"
53 
54 extern int main(int, char **, char **);
55 
56 #ifndef HAVE_INITFINI_ARRAY
57 extern void	_init(void);
58 extern void	_fini(void);
59 #endif
60 extern void	_libc_init(void);
61 
62 /*
63  * Arrange for _DYNAMIC to be weak and undefined (and therefore to show up
64  * as being at address zero, unless something else defines it).  That way,
65  * if we happen to be compiling without -static but with without any
66  * shared libs present, things will still work.
67  */
68 
69 __weakref_visible int rtld_DYNAMIC __weak_reference(_DYNAMIC);
70 
71 #ifdef MCRT0
72 extern void	monstartup(u_long, u_long);
73 extern void	_mcleanup(void);
74 extern unsigned char __etext, __eprol;
75 #endif /* MCRT0 */
76 
77 char		**environ;
78 struct ps_strings *__ps_strings = 0;
79 
80 static char	 empty_string[] = "";
81 char		*__progname = empty_string;
82 
83 __dead __dso_hidden void ___start(void (*)(void), const Obj_Entry *,
84 			 struct ps_strings *);
85 
86 #if !defined(__minix)
87 #define	write(fd, s, n)	__syscall(SYS_write, (fd), (s), (n))
88 #else
89 #define	write(fd, s, n) /* NO write() from here on minix */
90 #endif /* !defined(__minix) */
91 
92 #define	_FATAL(str)				\
93 do {						\
94 	write(2, str, sizeof(str)-1);		\
95 	_exit(1);				\
96 } while (0)
97 
98 #ifdef HAVE_INITFINI_ARRAY
99 /*
100  * If we are using INIT_ARRAY/FINI_ARRAY and we are linked statically,
101  * we have to process these instead of relying on RTLD to do it for us.
102  *
103  * Since we don't need .init or .fini sections, just code them in C
104  * to make life easier.
105  */
106 __weakref_visible const fptr_t preinit_array_start[1]
107     __weak_reference(__preinit_array_start);
108 __weakref_visible const fptr_t preinit_array_end[1]
109     __weak_reference(__preinit_array_end);
110 __weakref_visible const fptr_t init_array_start[1]
111     __weak_reference(__init_array_start);
112 __weakref_visible const fptr_t init_array_end[1]
113     __weak_reference(__init_array_end);
114 __weakref_visible const fptr_t fini_array_start[1]
115     __weak_reference(__fini_array_start);
116 __weakref_visible const fptr_t fini_array_end[1]
117     __weak_reference(__fini_array_end);
118 
119 static inline void
120 _preinit(void)
121 {
122 	for (const fptr_t *f = preinit_array_start; f < preinit_array_end; f++) {
123 		(*f)();
124 	}
125 }
126 
127 static inline void
128 _init(void)
129 {
130 	for (const fptr_t *f = init_array_start; f < init_array_end; f++) {
131 		(*f)();
132 	}
133 }
134 
135 static void
136 _fini(void)
137 {
138 	for (const fptr_t *f = fini_array_start; f < fini_array_end; f++) {
139 		(*f)();
140 	}
141 }
142 #endif /* HAVE_INITFINI_ARRAY */
143 
144 void
145 ___start(void (*cleanup)(void),			/* from shared loader */
146     const Obj_Entry *obj,			/* from shared loader */
147     struct ps_strings *ps_strings)
148 {
149 
150 	if (ps_strings == NULL)
151 		_FATAL("ps_strings missing\n");
152 	__ps_strings = ps_strings;
153 
154 	environ = ps_strings->ps_envstr;
155 
156 	if (ps_strings->ps_argvstr[0] != NULL) {
157 		char *c;
158 		__progname = ps_strings->ps_argvstr[0];
159 		for (c = ps_strings->ps_argvstr[0]; *c; ++c) {
160 			if (*c == '/')
161 				__progname = c + 1;
162 		}
163 	} else {
164 		__progname = empty_string;
165 	}
166 
167 	if (&rtld_DYNAMIC != NULL) {
168 		if (obj == NULL)
169 			_FATAL("NULL Obj_Entry pointer in GOT\n");
170 		if (obj->magic != RTLD_MAGIC)
171 			_FATAL("Corrupt Obj_Entry pointer in GOT\n");
172 		if (obj->version != RTLD_VERSION)
173 			_FATAL("Dynamic linker version mismatch\n");
174 		atexit(cleanup);
175 	}
176 
177 	_libc_init();
178 
179 #ifdef HAVE_INITFINI_ARRAY
180 	_preinit();
181 #endif
182 
183 #ifdef MCRT0
184 	atexit(_mcleanup);
185 	monstartup((u_long)&__eprol, (u_long)&__etext);
186 #endif
187 
188 	atexit(_fini);
189 	_init();
190 
191 	exit(main(ps_strings->ps_nargvstr, ps_strings->ps_argvstr, environ));
192 }
193