sysdeps/generic/dl-sysdep.c

   1 /* Operating system support for run-time dynamic linker.  Generic Unix version.
   2 Copyright (C) 1995 Free Software Foundation, Inc.
   3 This file is part of the GNU C Library.
   4
   5 The GNU C Library is free software; you can redistribute it and/or
   6 modify it under the terms of the GNU Library General Public License as
   7 published by the Free Software Foundation; either version 2 of the
   8 License, or (at your option) any later version.
   9
  10 The GNU C Library is distributed in the hope that it will be useful,
  11 but WITHOUT ANY WARRANTY; without even the implied warranty of
  12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13 Library General Public License for more details.
  14
  15 You should have received a copy of the GNU Library General Public
  16 License along with the GNU C Library; see the file COPYING.LIB.  If
  17 not, write to the Free Software Foundation, Inc., 675 Mass Ave,
  18 Cambridge, MA 02139, USA.  */
  19
  20 #include <elf.h>
  21 #include <sys/types.h>
  22 #include <fcntl.h>
  23 #include <link.h>
  24 #include <unistd.h>
  25
  26 extern int _dl_argc;
  27 extern char **_dl_argv;
  28 extern char **_environ;
  29 extern void _start (void);
  30
  31 Elf32_Addr
  32 _dl_sysdep_start (void **start_argptr,
  33                   void (*dl_main) (const Elf32_Phdr *phdr, Elf32_Word phnum,
  34                                    Elf32_Addr *user_entry))
  35 {
  36   const Elf32_Phdr *phdr;
  37   Elf32_Word phnum;
  38   Elf32_Addr user_entry;
  39   Elf32_auxv_t *av;
  40   uid_t uid, euid;
  41   gid_t gid, egid;
  42
  43   user_entry = (Elf32_Addr) &_start;
  44   _dl_argc = *(int *) start_argptr;
  45   _dl_argv = (char **) start_argptr + 1;
  46   _environ = &_dl_argv[_dl_argc + 1];
  47   start_argptr = (void **) _environ;
  48   while (*start_argptr)
  49     ++start_argptr;
  50
  51   for (av = (void *) ++start_argptr; av->a_type != AT_NULL; ++av)
  52     switch (av->a_type)
  53       {
  54       case AT_PHDR:
  55         phdr = av->a_un.a_ptr;
  56         break;
  57       case AT_PHNUM:
  58         phnum = av->a_un.a_val;
  59         break;
  60       case AT_ENTRY:
  61         user_entry = av->a_un.a_val;
  62         break;
  63       case AT_UID:
  64         uid = av->a_un.a_val;
  65         break;
  66       case AT_GID:
  67         gid = av->a_un.a_val;
  68         break;
  69       case AT_EUID:
  70         euid = av->a_un.a_val;
  71         break;
  72       case AT_EGID:
  73         egid = av->a_un.a_val;
  74         break;
  75       }
  76
  77   _dl_secure = uid != euid || gid != egid;
  78
  79   (*dl_main) (phdr, phnum, &user_entry);
  80   return user_entry;
  81 }
  82
  83 int
  84 _dl_sysdep_open_zero_fill (void)
  85 {
  86   return open ("/dev/zero", O_RDONLY);
  87 }
  88
  89 #include <stdarg.h>
  90
  91 void
  92 _dl_sysdep_fatal (const char *msg, ...)
  93 {
  94   va_list ap;
  95
  96   va_start (ap, msg);
  97   do
  98     {
  99       size_t len = strlen (msg);
 100       write (STDERR_FILENO, msg, len);
 101       msg = va_arg (ap, const char *);
 102     } while (msg);
 103   va_end (ap);
 104
 105   _exit (127);
 106 }
 107
 108
 109 void
 110 _dl_sysdep_message (const char *msg, ...)
 111 {
 112   va_list ap;
 113
 114   va_start (ap, msg);
 115   do
 116     {
 117       size_t len = strlen (msg);
 118       write (STDOUT_FILENO, msg, len);
 119       msg = va_arg (ap, const char *);
 120     } while (msg);
 121   va_end (ap);
 122 }