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crt0-common.c revision 1.7.2.2 
      1 /* $NetBSD: crt0-common.c,v 1.7.2.2 2012/10/30 18:58:37 yamt 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 1.7.2.2 2012/10/30 18:58:37 yamt Exp $");
     40 
     41 #include <sys/types.h>
     42 #include <sys/exec.h>
     43 #include <sys/syscall.h>
     44 #include <machine/profile.h>
     45 #include <stdlib.h>
     46 #include <unistd.h>
     47 
     48 #include "rtld.h"
     49 
     50 extern int main(int, char **, char **);
     51 
     52 #ifndef HAVE_INITFINI_ARRAY
     53 extern void	_init(void);
     54 extern void	_fini(void);
     55 #endif
     56 extern void	_libc_init(void);
     57 
     58 /*
     59  * Arrange for _DYNAMIC to be weak and undefined (and therefore to show up
     60  * as being at address zero, unless something else defines it).  That way,
     61  * if we happen to be compiling without -static but with without any
     62  * shared libs present, things will still work.
     63  */
     64 
     65 __weakref_visible int rtld_DYNAMIC __weak_reference(_DYNAMIC);
     66 
     67 #ifdef MCRT0
     68 extern void	monstartup(u_long, u_long);
     69 extern void	_mcleanup(void);
     70 extern unsigned char __etext, __eprol;
     71 #endif /* MCRT0 */
     72 
     73 char		**environ;
     74 struct ps_strings *__ps_strings = 0;
     75 
     76 static char	 empty_string[] = "";
     77 char		*__progname = empty_string;
     78 
     79 __dead __dso_hidden void ___start(void (*)(void), const Obj_Entry *,
     80 			 struct ps_strings *);
     81 
     82 #define	write(fd, s, n)	__syscall(SYS_write, (fd), (s), (n))
     83 
     84 #define	_FATAL(str)				\
     85 do {						\
     86 	write(2, str, sizeof(str)-1);		\
     87 	_exit(1);				\
     88 } while (0)
     89 
     90 #ifdef HAVE_INITFINI_ARRAY
     91 /*
     92  * If we are using INIT_ARRAY/FINI_ARRAY and we are linked statically,
     93  * we have to process these instead of relying on RTLD to do it for us.
     94  *
     95  * Since we don't need .init or .fini sections, just code them in C
     96  * to make life easier.
     97  */
     98 static const fptr_t init_array_start[] __weak_reference(__init_array_start);
     99 static const fptr_t init_array_end[] __weak_reference(__init_array_end);
    100 static const fptr_t fini_array_start[] __weak_reference(__fini_array_start);
    101 static const fptr_t fini_array_end[] __weak_reference(__fini_array_end);
    102 
    103 static inline void
    104 _init(void)
    105 {
    106 	for (const fptr_t *f = init_array_start; f < init_array_end; f++) {
    107 		(*f)();
    108 	}
    109 }
    110 
    111 static void
    112 _fini(void)
    113 {
    114 	for (const fptr_t *f = fini_array_start; f < fini_array_end; f++) {
    115 		(*f)();
    116 	}
    117 }
    118 #endif /* HAVE_INITFINI_ARRAY */
    119 
    120 void
    121 ___start(void (*cleanup)(void),			/* from shared loader */
    122     const Obj_Entry *obj,			/* from shared loader */
    123     struct ps_strings *ps_strings)
    124 {
    125 
    126 	if (ps_strings == NULL)
    127 		_FATAL("ps_strings missing\n");
    128 	__ps_strings = ps_strings;
    129 
    130 	environ = ps_strings->ps_envstr;
    131 
    132 	if (ps_strings->ps_argvstr[0] != NULL) {
    133 		char *c;
    134 		__progname = ps_strings->ps_argvstr[0];
    135 		for (c = ps_strings->ps_argvstr[0]; *c; ++c) {
    136 			if (*c == '/')
    137 				__progname = c + 1;
    138 		}
    139 	} else {
    140 		__progname = empty_string;
    141 	}
    142 
    143 	if (&rtld_DYNAMIC != NULL) {
    144 		if (obj == NULL)
    145 			_FATAL("NULL Obj_Entry pointer in GOT\n");
    146 		if (obj->magic != RTLD_MAGIC)
    147 			_FATAL("Corrupt Obj_Entry pointer in GOT\n");
    148 		if (obj->version != RTLD_VERSION)
    149 			_FATAL("Dynamic linker version mismatch\n");
    150 		atexit(cleanup);
    151 	}
    152 
    153 	_libc_init();
    154 
    155 #ifdef MCRT0
    156 	atexit(_mcleanup);
    157 	monstartup((u_long)&__eprol, (u_long)&__etext);
    158 #endif
    159 
    160 	atexit(_fini);
    161 	_init();
    162 
    163 	exit(main(ps_strings->ps_nargvstr, ps_strings->ps_argvstr, environ));
    164 }
    165