lib/csu/common/crt0-common.c

   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 }