lib/csu/common/crt0-common.c

   1 /* $NetBSD: crt0-common.c,v 1.9 2012/08/13 02:15:35 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 1.9 2012/08/13 02:15:35 matt Exp $");
  40
  41 #include <sys/types.h>
  42 #include <sys/exec.h>
  43 #ifndef __minix
  44 #include <sys/syscall.h>
  45 #endif
  46 #include <machine/profile.h>
  47 #include <stdlib.h>
  48 #include <unistd.h>
  49
  50 #include "rtld.h"
  51
  52 extern int main(int, char **, char **);
  53
  54 #ifndef HAVE_INITFINI_ARRAY
  55 extern void     _init(void);
  56 extern void     _fini(void);
  57 #endif
  58 extern void     _libc_init(void);
  59
  60 /*
  61  * Arrange for _DYNAMIC to be weak and undefined (and therefore to show up
  62  * as being at address zero, unless something else defines it).  That way,
  63  * if we happen to be compiling without -static but with without any
  64  * shared libs present, things will still work.
  65  */
  66
  67 __weakref_visible int rtld_DYNAMIC __weak_reference(_DYNAMIC);
  68
  69 #ifdef MCRT0
  70 extern void     monstartup(u_long, u_long);
  71 extern void     _mcleanup(void);
  72 extern unsigned char __etext, __eprol;
  73 #endif /* MCRT0 */
  74
  75 char            **environ;
  76 struct ps_strings *__ps_strings = 0;
  77
  78 static char      empty_string[] = "";
  79 char            *__progname = empty_string;
  80
  81 #ifndef __minix
  82 __dead __dso_hidden void ___start(void (*)(void), const Obj_Entry *,
  83                          struct ps_strings *);
  84
  85 #define write(fd, s, n) __syscall(SYS_write, (fd), (s), (n))
  86 #else
  87 __dead __dso_hidden void ___start(int, char **, char **, void (*)(void),
  88                         const Obj_Entry *, struct ps_strings *);
  89
  90 #define write(fd, s, n) /* NO write() from here on minix */
  91 #endif
  92
  93 #define _FATAL(str)                             \
  94 do {                                            \
  95         write(2, str, sizeof(str)-1);           \
  96         _exit(1);                               \
  97 } while (0)
  98
  99 #ifdef HAVE_INITFINI_ARRAY
 100 /*
 101  * If we are using INIT_ARRAY/FINI_ARRAY and we are linked statically,
 102  * we have to process these instead of relying on RTLD to do it for us.
 103  *
 104  * Since we don't need .init or .fini sections, just code them in C
 105  * to make life easier.
 106  */
 107 static const fptr_t init_array_start[] __weak_reference(__init_array_start);
 108 static const fptr_t init_array_end[] __weak_reference(__init_array_end);
 109 static const fptr_t fini_array_start[] __weak_reference(__fini_array_start);
 110 static const fptr_t fini_array_end[] __weak_reference(__fini_array_end);
 111
 112 static inline void
 113 _init(void)
 114 {
 115         for (const fptr_t *f = init_array_start; f < init_array_end; f++) {
 116                 (*f)();
 117         }
 118 }
 119
 120 static void
 121 _fini(void)
 122 {
 123         for (const fptr_t *f = fini_array_start; f < fini_array_end; f++) {
 124                 (*f)();
 125         }
 126 }
 127 #endif /* HAVE_INITFINI_ARRAY */
 128
 129 void
 130 #ifdef __minix
 131 ___start(int argc, char **argv, char **envp,
 132     void (*cleanup)(void),                 /* from shared loader */
 133 #else
 134 ___start(void (*cleanup)(void),                 /* from shared loader */
 135 #endif /* __minix */
 136     const Obj_Entry *obj,                       /* from shared loader */
 137     struct ps_strings *ps_strings)
 138 {
 139 #ifdef __minix
 140         /* LSC: We have not yet updated the way we pass arguments to
 141                 the userspace, so here some code to adapt this to the new
 142                 ways. */
 143         struct ps_strings minix_ps_strings;
 144
 145         if (ps_strings == NULL) {
 146                 minix_ps_strings.ps_envstr = envp;
 147                 minix_ps_strings.ps_argvstr = argv;
 148                 minix_ps_strings.ps_nargvstr = argc;
 149                 ps_strings = &minix_ps_strings;
 150         }
 151 #endif /* __minix */
 152         if (ps_strings == NULL)
 153                 _FATAL("ps_strings missing\n");
 154         __ps_strings = ps_strings;
 155
 156         environ = ps_strings->ps_envstr;
 157
 158         if (ps_strings->ps_argvstr[0] != NULL) {
 159                 char *c;
 160                 __progname = ps_strings->ps_argvstr[0];
 161                 for (c = ps_strings->ps_argvstr[0]; *c; ++c) {
 162                         if (*c == '/')
 163                                 __progname = c + 1;
 164                 }
 165         } else {
 166                 __progname = empty_string;
 167         }
 168
 169         if (&rtld_DYNAMIC != NULL) {
 170                 if (obj == NULL)
 171                         _FATAL("NULL Obj_Entry pointer in GOT\n");
 172                 if (obj->magic != RTLD_MAGIC)
 173                         _FATAL("Corrupt Obj_Entry pointer in GOT\n");
 174                 if (obj->version != RTLD_VERSION)
 175                         _FATAL("Dynamic linker version mismatch\n");
 176                 atexit(cleanup);
 177         }
 178
 179         _libc_init();
 180
 181 #ifdef MCRT0
 182         atexit(_mcleanup);
 183         monstartup((u_long)&__eprol, (u_long)&__etext);
 184 #endif
 185
 186         atexit(_fini);
 187         _init();
 188
 189         exit(main(ps_strings->ps_nargvstr, ps_strings->ps_argvstr, environ));
 190 }