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428
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1 /* Code to do an unexec for FreeBSD-1.1 for a temacs linked -Bdynamic.
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2 Derived from unexnetbsd.c, which was derived from unexsunos4.c
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3 Copyright (C) 1992, 1993 Free Software Foundation, Inc.
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4
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5 This file is part of XEmacs.
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6
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7 XEmacs is free software; you can redistribute it and/or modify it
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8 under the terms of the GNU General Public License as published by the
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9 Free Software Foundation; either version 2, or (at your option) any
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10 later version.
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11
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12 XEmacs is distributed in the hope that it will be useful, but WITHOUT
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13 ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
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14 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
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15 for more details.
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16
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17 You should have received a copy of the GNU General Public License
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18 along with XEmacs; see the file COPYING. If not, write to
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19 the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
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20 Boston, MA 02111-1307, USA. */
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21
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22 /* Synched up with: Not in FSF? */
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23
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24 /*
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25 Created 29-Oct-92 by Harlan Sexton
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26 Tweaked 06-Aug-93 by Dean Michaels to work with sun3.
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27 Converted 01-Dec-93 by Paul Mackerras to work with NetBSD shared libraries.
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28 Tweaked 26-Feb-94 by Shawn Carey for use with FreeBSD-1.1 shared libraries.
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29 */
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30
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31 /********************** Included .h Files **************************/
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32
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33 #include <config.h>
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34
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35 #include <stdarg.h>
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36 #include <sys/param.h>
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37 #include <sys/mman.h>
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38 #include <sys/file.h>
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39 #include <sys/stat.h>
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40 #include <sys/types.h>
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41 #include <string.h>
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42 #include <stdio.h>
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438
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43 #include <errno.h>
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428
|
44 #include <a.out.h>
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45 #include <unistd.h>
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46 #include <ctype.h>
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47 #include <stab.h>
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48 #include <sys/dir.h>
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49 #include <link.h>
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50
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51 /********************** Macros *************************************/
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52
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53 #define SYS_ERR strerror(errno)
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54
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55 #define MASK_UP(x,p_of_two) \
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56 ((((unsigned long) (x)) + ((p_of_two) - 1)) & (~((p_of_two) - 1)))
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57
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58 #define MASK_DOWN(x,p_of_two) (((unsigned long) (x)) & (~((p_of_two) - 1)))
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59
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60 /********************** Typedefs and Structs ***********************/
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61
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62 struct translation_struct
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63 {
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64 long txtaddr;
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65 long txtoff;
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66 long dataddr;
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67 long datoff;
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68 long bssaddr;
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69 long endaddr;
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70 };
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71
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72 /********************** Function Prototypes/Declarations ***********/
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73
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74 static void unexec_error (CONST char *m, int use_errno, ...);
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75 static int unexec_open (char *filename, int flag, int mode);
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76 static caddr_t unexec_mmap (int fd, size_t len, int prot, int flags);
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77 static long unexec_seek (int fd, long position);
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78 static void unexec_read (int fd, long position, char *buf, int bytes);
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79 static void unexec_write (int fd, long position, char *buf, int bytes);
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80 static void unexec_pad (int fd, int bytes);
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81 static void unexec_fstat (int fd, struct stat *statptr);
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82 static void unexec_fchmod (int fd, int mode);
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83 static long unexec_addr_to_offset (long addr, struct translation_struct *ts);
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84 static void copy_relocation_site (struct relocation_info *ri,
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85 caddr_t from_base_addr,
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86 caddr_t to_base_addr,
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87 struct translation_struct *ts);
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88 static void reset_symtab (struct nlist *start, struct nlist *end,
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89 char *strtab, long edata_value, long end_value,
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90 int shlib_image);
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91 static void reset_ldso_symtab (struct nzlist *start, struct nzlist *end,
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92 char *strtab, long edata_value, long end_value,
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93 int shlib_image);
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94 int run_time_remap (char *dummy);
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95
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|
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96 /********************** Variables **********************************/
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97
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|
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98 /* for reporting error messages from system calls */
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99 extern int _DYNAMIC;
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100 extern char **environ;
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101
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102 static unsigned long sbrk_of_0_at_unexec;
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103
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104 /*******************************************************************/
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105
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106 static void
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107 unexec_error (CONST char *fmt, int use_errno, ...)
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108 {
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109 CONST char *err_msg = SYS_ERR;
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110 va_list args;
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111
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112 fprintf (stderr, "unexec - ");
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113 va_start (args, use_errno);
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114 vfprintf (stderr, fmt, args);
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115 va_end (args);
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116
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117 if (use_errno)
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118 fprintf (stderr, ": %s", err_msg);
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119 fprintf (stderr, "\n");
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120 exit (1);
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121 return;
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122 }
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123
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124 static int
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125 unexec_open (char *filename, int flag, int mode)
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126 {
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|
127 int fd;
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|
128
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|
129 errno = 0;
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130
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131 fd = open (filename, flag, mode);
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132
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133 if (fd < 0)
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134 unexec_error ("Failure opening file %s", 1, filename);
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135 return fd;
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|
136 }
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137
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138 static caddr_t
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139 unexec_mmap (int fd, size_t len, int prot, int flags)
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140 {
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141 caddr_t return_val;
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142
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143 unexec_seek (fd, 0);
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144 errno = 0;
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145 return_val = mmap (0, len, prot, flags, fd, 0);
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146
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147 if (return_val == (caddr_t) -1)
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148 unexec_error ("Failure mmap'ing file", 1);
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149 return return_val;
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150 }
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151
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152
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153 static long
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154 unexec_seek (int fd, long position)
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155 {
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|
156 long seek_value;
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157
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158 if (fd <= 0)
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|
159 unexec_error ("No file open in which to seek", 0);
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160
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161 errno = 0;
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162
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163 if (position < 0)
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164 seek_value = (long) lseek (fd, 0, L_INCR);
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165 else
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166 seek_value = (long) lseek (fd, position, L_SET);
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167
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|
168 if (seek_value < 0)
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169 unexec_error ("Failed to do a seek to 0x%x in %s", 1,
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170 position, "unexec() output file");
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171
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172 return seek_value;
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173 }
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174
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175 static void
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176 unexec_read (int fd, long position, char *buf, int bytes)
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177 {
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178 int n_read;
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|
179 int remains = bytes;
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180 position = unexec_seek (fd, position);
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181
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182 if (bytes < 0)
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183 unexec_error ("Attempted read of %d bytes", 0, bytes);
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184
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185 errno = 0;
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186
|
|
|
187 while (remains > 0)
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|
188 {
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|
189 n_read = read (fd, buf, remains);
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190 if (n_read <= 0)
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|
191 unexec_error ("Read failed for 0x%x bytes at offset 0x%x in %s",
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|
192 1, bytes, position, "unexec() output file");
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|
193 buf += n_read;
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|
194 remains -= n_read;
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195 }
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196
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|
197 return;
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198 }
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199
|
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|
200 static void
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201 unexec_write (int fd, long position, char *buf, int bytes)
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202 {
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|
203 int n_written;
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204 int remains = bytes;
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205 position = unexec_seek (fd, position);
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206
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207 if (bytes < 0)
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|
208 unexec_error ("Attempted write of %d bytes in %s",
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|
209 0, bytes, "unexec() output file");
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|
210
|
|
|
211 errno = 0;
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212
|
|
|
213 while (remains > 0)
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|
|
214 {
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|
|
215 n_written = write (fd, buf, remains);
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|
|
216 if (n_written <= 0)
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|
|
217 unexec_error ("Write failed for 0x%x bytes at offset 0x%x in %s",
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|
|
218 1, bytes, position, "unexec() output file");
|
|
|
219 buf += n_written;
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|
|
220 remains -= n_written;
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|
|
221 }
|
|
|
222
|
|
|
223 return;
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|
|
224 }
|
|
|
225
|
|
|
226 static void
|
|
|
227 unexec_pad (int fd, int bytes)
|
|
|
228 {
|
|
|
229 if (bytes > 0)
|
|
|
230 {
|
|
|
231 char buf[1024];
|
|
|
232 int remaining = bytes;
|
|
|
233
|
|
|
234 memset (buf, 0, sizeof (buf));
|
|
|
235
|
|
|
236 while (remaining > 0)
|
|
|
237 {
|
|
|
238 int this_write = (remaining > sizeof(buf))?sizeof(buf):remaining;
|
|
|
239 unexec_write (fd, -1, buf, this_write);
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|
|
240 remaining -= this_write;
|
|
|
241 }
|
|
|
242 }
|
|
|
243 }
|
|
|
244
|
|
|
245 static void
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|
|
246 unexec_fstat (int fd, struct stat *statptr)
|
|
|
247 {
|
|
|
248 errno = 0;
|
|
|
249 if (-1 == fstat (fd, statptr))
|
|
|
250 unexec_error ("fstat() failed for descriptor %d", 1, fd);
|
|
|
251 return;
|
|
|
252 }
|
|
|
253
|
|
|
254 static void
|
|
|
255 unexec_fchmod (int fd, int mode)
|
|
|
256 {
|
|
|
257 errno = 0;
|
|
|
258 if (-1 == fchmod (fd, mode))
|
|
|
259 unexec_error ("fchmod() failed for descriptor %d", 1, fd);
|
|
|
260 return;
|
|
|
261 }
|
|
|
262
|
|
|
263 static long
|
|
|
264 unexec_addr_to_offset (long addr, struct translation_struct *ts)
|
|
|
265
|
|
|
266 {
|
|
|
267 if ((addr < ts->txtaddr) || (addr >= ts->bssaddr))
|
|
|
268 return -1;
|
|
|
269 else if (addr >= ts->dataddr)
|
|
|
270 return ((long) ((addr - ts->dataddr) + ts->datoff));
|
|
|
271 else
|
|
|
272 return ((long) ((addr - ts->txtaddr) + ts->txtoff));
|
|
|
273 }
|
|
|
274
|
|
|
275
|
|
|
276 /*
|
|
|
277 * "LD.SO" DATA AND SYMBOL TABLE OPERATIONS
|
|
|
278 */
|
|
|
279
|
|
|
280 static void
|
|
|
281 copy_relocation_site (struct relocation_info *ri,
|
|
|
282 caddr_t from_base_addr,
|
|
|
283 caddr_t to_base_addr,
|
|
|
284 struct translation_struct *ts)
|
|
|
285 {
|
|
|
286 long offset;
|
|
|
287 caddr_t from, to;
|
|
|
288
|
|
|
289 /* We can get relocation sites in the bss region, for objects whose
|
|
|
290 contents are copied from a shared library. We don't need or want
|
|
|
291 to restore these at present. */
|
|
|
292 #ifndef sparc
|
|
|
293 if (ri->r_copy)
|
|
|
294 return;
|
|
|
295 #else
|
|
|
296 /* Struct relocation_info_sparc doesn't have member r_copy.
|
|
|
297 Instead, we use the address to check if this is run-time-copied. */
|
|
|
298 if (ri->r_address >= ts->bssaddr && ri->r_address < ts->endaddr)
|
|
|
299 return;
|
|
|
300 #endif
|
|
|
301
|
|
|
302 offset = unexec_addr_to_offset (ri->r_address, ts);
|
|
|
303 if (offset == -1)
|
|
|
304 unexec_error ("bad relocation address 0x%x (0x%x)", 0, ri->r_address,
|
|
|
305 ((long *)ri)[1]);
|
|
|
306
|
|
|
307 from = from_base_addr + offset;
|
|
|
308 to = to_base_addr + offset;
|
|
|
309 /* This stuff should be in a md_ file somewhere... */
|
|
|
310 #ifndef sparc
|
|
|
311 switch (ri->r_length)
|
|
|
312 {
|
|
|
313 case 0:
|
|
|
314 *((char *) to) = *((char *) from);
|
|
|
315 break;
|
|
|
316 case 1:
|
|
|
317 *((short *) to) = *((short *) from);
|
|
|
318 break;
|
|
|
319 case 2:
|
|
|
320 *((long *) to) = *((long *) from);
|
|
|
321 break;
|
|
|
322 default:
|
|
|
323 unexec_error ("unknown reloc length %d seen during unexec()",
|
|
|
324 0, ri->r_length);
|
|
|
325 break;
|
|
|
326 }
|
|
|
327 #else /* sparc */
|
|
|
328 switch (ri->r_type)
|
|
|
329 {
|
|
|
330 case RELOC_8:
|
|
|
331 case RELOC_DISP8:
|
|
|
332 *((char *) to) = *((char *) from);
|
|
|
333 break;
|
|
|
334 case RELOC_16:
|
|
|
335 case RELOC_DISP16:
|
|
|
336 *((short *) to) = *((short *) from);
|
|
|
337 break;
|
|
|
338 case RELOC_LO10:
|
|
|
339 case RELOC_13:
|
|
|
340 case RELOC_22:
|
|
|
341 case RELOC_HI22:
|
|
|
342 case RELOC_WDISP22:
|
|
|
343 case RELOC_WDISP30:
|
|
|
344 case RELOC_32:
|
|
|
345 case RELOC_DISP32:
|
|
|
346 case RELOC_GLOB_DAT:
|
|
|
347 *((long *) to) = *((long *) from);
|
|
|
348 break;
|
|
|
349 case RELOC_JMP_SLOT:
|
|
|
350 {
|
|
|
351 long *target = (long *) to;
|
|
|
352 long *source = (long *) from;
|
|
|
353 *target = *source;
|
|
|
354 target++;
|
|
|
355 source++;
|
|
|
356 *target = *source;
|
|
|
357 target++;
|
|
|
358 source++;
|
|
|
359 *target = *source;
|
|
|
360 }
|
|
|
361 break;
|
|
|
362 default:
|
|
|
363 unexec_error ("unknown reloc type %d seen during unexec()",
|
|
|
364 0, ri->r_type);
|
|
|
365 break;
|
|
|
366 }
|
|
|
367 #endif /* sparc */
|
|
|
368 }
|
|
|
369
|
|
|
370 static void
|
|
|
371 reset_symtab (struct nlist *start, struct nlist *end, char *strtab,
|
|
|
372 long edata_value, long end_value, int shlib_image)
|
|
|
373 {
|
|
|
374 struct nlist *tmp = start;
|
|
|
375 int found_edata = 0;
|
|
|
376 int found_end = 0;
|
|
|
377
|
|
|
378 while (tmp < end)
|
|
|
379 {
|
|
|
380 int type = tmp->n_type;
|
|
|
381
|
|
|
382 if ((type == (N_UNDF | N_EXT)) &&
|
|
|
383 (tmp->n_value != 0))
|
|
|
384 unexec_error ("unexec'ing image has COMMON symbols in it -- we quit!",
|
|
|
385 0);
|
|
|
386
|
|
|
387 if (!(type & N_STAB))
|
|
|
388 {
|
|
|
389 if (!found_edata &&
|
|
|
390 (type == (N_EXT | N_DATA)) &&
|
|
|
391 tmp->n_un.n_strx &&
|
|
|
392 !strcmp ("_edata", strtab + tmp->n_un.n_strx))
|
|
|
393 {
|
|
|
394 tmp->n_value = edata_value;
|
|
|
395 found_edata = 1;
|
|
|
396 }
|
|
|
397
|
|
|
398
|
|
|
399 if ((type & N_TYPE) == N_BSS)
|
|
|
400 {
|
|
|
401 if (!found_end &&
|
|
|
402 (type == (N_EXT | N_BSS)) &&
|
|
|
403 tmp->n_un.n_strx &&
|
|
|
404 !strcmp ("_end", strtab + tmp->n_un.n_strx))
|
|
|
405 {
|
|
|
406 tmp->n_value = end_value;
|
|
|
407 found_end = 1;
|
|
|
408 }
|
|
|
409 else if (type & N_EXT)
|
|
|
410 tmp->n_type = N_DATA | N_EXT;
|
|
|
411 else
|
|
|
412 tmp->n_type = N_DATA;
|
|
|
413 }
|
|
|
414
|
|
|
415 /* the way things are being handled here, having sbrk() in the
|
|
|
416 image is fatal for an image linked with shared lib's (although
|
|
|
417 the code could be modified to support it), but this should
|
|
|
418 never happen anyway */
|
|
|
419 if (shlib_image &&
|
|
|
420 (type == (N_EXT | N_TEXT)) &&
|
|
|
421 tmp->n_un.n_strx &&
|
|
|
422 !strcmp ("_sbrk", strtab + tmp->n_un.n_strx))
|
|
|
423 unexec_error ("unexec'd shlib image has sbrk() in it -- we quit!",
|
|
|
424 0);
|
|
|
425 }
|
|
|
426
|
|
|
427 tmp++;
|
|
|
428 }
|
|
|
429 }
|
|
|
430
|
|
|
431 static void
|
|
|
432 reset_ldso_symtab (struct nzlist *start, struct nzlist *end, char *strtab,
|
|
|
433 long edata_value, long end_value, int shlib_image)
|
|
|
434 {
|
|
|
435 struct nzlist *tmp = start;
|
|
|
436 int found_edata = 0;
|
|
|
437 int found_end = 0;
|
|
|
438
|
|
|
439 while (tmp < end) {
|
|
|
440 int type = tmp->nz_type;
|
|
|
441 /*
|
|
|
442 * the following code breaks under FreeBSD-1.1-BETA, but everything
|
|
|
443 * seems to work perfectly if it's commented out. This did not break
|
|
|
444 * anything until the changes to ld.so were made.
|
|
|
445 */
|
|
|
446 /*
|
|
|
447 if ((type == (N_UNDF | N_EXT)) && (tmp->nz_value != 0))
|
|
|
448 unexec_error("unexec'ing image has COMMON symbols in rel -- we quit!",0);
|
|
|
449 */
|
|
|
450 if (!(type & N_STAB)) {
|
|
|
451 if (!found_edata &&
|
|
|
452 (type == (N_EXT | N_DATA)) &&
|
|
|
453 !strcmp ("_edata", strtab + tmp->nz_strx)) {
|
|
|
454 tmp->nz_value = edata_value;
|
|
|
455 found_edata = 1;
|
|
|
456 }
|
|
|
457
|
|
|
458 if ((type & N_TYPE) == N_BSS) {
|
|
|
459 if (!found_end &&
|
|
|
460 (type == (N_EXT | N_BSS)) &&
|
|
|
461 !strcmp ("_end", strtab + tmp->nz_strx)) {
|
|
|
462 tmp->nz_value = end_value;
|
|
|
463 found_end = 1;
|
|
|
464 } else if (type & N_EXT)
|
|
|
465 tmp->nz_type = N_DATA | N_EXT;
|
|
|
466 else
|
|
|
467 tmp->nz_type = N_DATA;
|
|
|
468 }
|
|
|
469
|
|
|
470 /* the way things are being handled here, having sbrk() in the
|
|
|
471 image is fatal for an image linked with shared lib's (although
|
|
|
472 the code could be modified to support it), but this should
|
|
|
473 never happen anyway */
|
|
|
474 if (shlib_image &&
|
|
|
475 (type == (N_EXT | N_TEXT)) &&
|
|
|
476 !strcmp ("_sbrk", strtab + tmp->nz_strx))
|
|
|
477 unexec_error("unexec'd shlib image has sbrk() ref -- we quit!", 0);
|
|
|
478 }
|
|
|
479 tmp++;
|
|
|
480 }
|
|
|
481 }
|
|
|
482
|
|
|
483 extern int getpagesize (void);
|
|
|
484
|
|
|
485 /*
|
|
|
486 * EXPORTED FUNCTIONS
|
|
|
487 */
|
|
|
488
|
|
|
489 /* this has to be a global variable to prevent the optimizers from
|
|
|
490 * assuming that it can not be 0.
|
|
|
491 */
|
|
|
492 static void *dynamic_addr = (void *) &_DYNAMIC;
|
|
|
493
|
|
|
494 int
|
|
|
495 unexec (char *new_name, char *old_name,
|
|
|
496 unsigned int emacs_edata, unsigned int dummy1, unsigned int dummy2)
|
|
|
497 {
|
|
|
498 /* ld.so data */
|
|
|
499 struct _dynamic *ld = 0;
|
|
|
500 struct section_dispatch_table *ld2 = 0;
|
|
|
501 /* old and new state */
|
|
|
502 int old_fd;
|
|
|
503 int new_fd;
|
|
|
504 caddr_t old_base_addr;
|
|
|
505 caddr_t new_base_addr;
|
|
|
506 struct exec old_hdr;
|
|
|
507 struct exec new_hdr;
|
|
|
508 struct stat old_buf;
|
|
|
509 struct stat new_buf;
|
|
|
510 /* some process specific "constants" */
|
|
|
511 unsigned long n_pagsiz, new_edata;
|
|
|
512 long page_size = getpagesize ();
|
|
|
513 caddr_t plt_end;
|
|
|
514 caddr_t current_break = (caddr_t) sbrk (0);
|
|
|
515
|
|
|
516 if (!page_size)
|
|
|
517 unexec_error ("unexec() failed because we can't get the size of a page!",
|
|
|
518 0);
|
|
|
519
|
|
|
520 /* see if this is a -Bdynamic image -- if so, find ld.so structures */
|
|
|
521 if (dynamic_addr)
|
|
|
522 {
|
|
|
523 ld = (struct _dynamic *) dynamic_addr;
|
|
|
524 ld2 = ld->d_un.d_sdt;
|
|
|
525 if (ld->d_version < LD_VERSION_BSD)
|
|
|
526 unexec_error ("%s linked with obsolete version of ld -- we quit!",
|
|
|
527 0, old_name);
|
|
|
528 }
|
|
|
529
|
|
|
530 /* open the old and new files, figuring out how big the old one is
|
|
|
531 so that we can map it in */
|
|
|
532 old_fd = unexec_open (old_name, O_RDONLY, 0);
|
|
|
533 new_fd = unexec_open (new_name, O_RDWR | O_CREAT | O_TRUNC, 0666);
|
|
|
534
|
|
|
535 /* setup the header and the statbuf for old_fd */
|
|
|
536 unexec_read (old_fd, 0, (char *) &old_hdr, sizeof (old_hdr));
|
|
|
537 unexec_fstat (old_fd, &old_buf);
|
|
|
538
|
|
|
539
|
|
|
540 /* set up some important constants */
|
|
|
541 n_pagsiz = __LDPGSZ;
|
|
|
542 if (dynamic_addr)
|
|
|
543 plt_end = (caddr_t) MASK_UP (ld2->sdt_plt + ld2->sdt_plt_sz, sizeof (double));
|
|
|
544 else
|
|
|
545 plt_end = (caddr_t) N_DATADDR (old_hdr);
|
|
|
546
|
|
|
547 #if 0
|
|
|
548 /* never write protect the variable "environ", defined in /lib/crt0.o, and
|
|
|
549 set in process.c and callproc.c */
|
|
|
550 mprotect_bottom_addr = ((unsigned long) &environ) + sizeof (char **);
|
|
|
551 /* never protect ABOVE the end of data emacs_edata specified */
|
|
|
552 mprotect_top_addr = MIN (emacs_edata, N_DATADDR (old_hdr) + old_hdr.a_data);
|
|
|
553 #endif
|
|
|
554
|
|
|
555 /* Set up the image of the old file */
|
|
|
556 old_base_addr = unexec_mmap (old_fd, old_buf.st_size, PROT_READ,
|
|
|
557 MAP_FILE | MAP_PRIVATE);
|
|
|
558 close (old_fd);
|
|
|
559
|
|
|
560 /* set up the new exec */
|
|
|
561 new_hdr = old_hdr;
|
|
|
562 new_edata = (unsigned long) MASK_UP (current_break, n_pagsiz);
|
|
|
563 new_hdr.a_data = new_edata - ((unsigned long) N_DATADDR (old_hdr));
|
|
|
564 new_hdr.a_bss = 0;
|
|
|
565
|
|
|
566 /* set up this variable, in case we want to reset "the break"
|
|
|
567 when restarting */
|
|
|
568 sbrk_of_0_at_unexec = ((unsigned long) MASK_UP (current_break, n_pagsiz));
|
|
|
569
|
|
|
570 /* Write out the first approximation to the new file. The sizes of
|
|
|
571 each section will be correct, but there will be a number of
|
|
|
572 corrections that will need to be made. */
|
|
|
573 {
|
|
|
574 long old_datoff = N_DATOFF (old_hdr);
|
|
|
575 long old_dataddr = N_DATADDR (old_hdr);
|
|
|
576 long new_treloff = N_RELOFF (new_hdr);
|
|
|
577 long old_treloff = N_RELOFF (old_hdr);
|
|
|
578 long ld_so_size = ((unsigned long) plt_end) - old_dataddr;
|
|
|
579 long real_data_size = current_break - plt_end;
|
|
|
580 long pad_size =
|
|
|
581 MASK_UP (current_break, n_pagsiz) - ((unsigned long) current_break);
|
|
|
582
|
|
|
583
|
|
|
584 /* First, write the text segment with new header -- copy everything until
|
|
|
585 the start of the data segment from the old file, and then go back and
|
|
|
586 write the new header. */
|
|
|
587 unexec_write (new_fd, 0, old_base_addr, old_datoff + ld_so_size);
|
|
|
588 unexec_write (new_fd, 0, (char *) &new_hdr, sizeof (new_hdr));
|
|
|
589
|
|
|
590 /* Copy the rest of the data segment from the running image. */
|
|
|
591 unexec_write (new_fd, old_datoff + ld_so_size,
|
|
|
592 plt_end, real_data_size);
|
|
|
593
|
|
|
594 /* pad out the data segment */
|
|
|
595 unexec_pad (new_fd, pad_size);
|
|
|
596
|
|
|
597 /* Finally, copy the symbol table information from the old file. */
|
|
|
598 unexec_write (new_fd, new_treloff,
|
|
|
599 old_base_addr + old_treloff,
|
|
|
600 old_buf.st_size - old_treloff);
|
|
|
601 }
|
|
|
602
|
|
|
603
|
|
|
604 /* Next, map in the output file so that we can jump around fixing it
|
|
|
605 up. We retain the old file so that we can refer to it. */
|
|
|
606 unexec_fstat (new_fd, &new_buf);
|
|
|
607 new_base_addr = unexec_mmap (new_fd,
|
|
|
608 MASK_UP (new_buf.st_size, page_size),
|
|
|
609 PROT_READ | PROT_WRITE,
|
|
|
610 MAP_FILE | MAP_SHARED);
|
|
|
611
|
|
|
612
|
|
|
613
|
|
|
614 /* We need to do 2 things. First, make sure that _edata and _end (and
|
|
|
615 hence, curbrk) are set to the correct values. At the same time, for
|
|
|
616 neatness and to help with debugging, mark all the types of all ld.so
|
|
|
617 and nm BSS symbols in the new file to be DATA, and make sure that
|
|
|
618 there are no COMMON symbols in the output file, as any references to
|
|
|
619 these can lose really big. Second, reset all of the ld.so "relocation
|
|
|
620 sites" in the new file to have the values that appear in the old file
|
|
|
621 -- the failure to do this was the biggest loser in the old version of
|
|
|
622 this code. */
|
|
|
623
|
|
|
624 /* STEP 1 */
|
|
|
625 /* Reset the regular symbol table first. */
|
|
|
626 reset_symtab ((struct nlist *) (new_base_addr + N_SYMOFF(new_hdr)),
|
|
|
627 (struct nlist *) (new_base_addr + N_SYMOFF(new_hdr) +
|
|
|
628 new_hdr.a_syms),
|
|
|
629 (char *) (new_base_addr + N_STROFF(new_hdr)),
|
|
|
630 new_edata, new_edata,
|
|
|
631 !!dynamic_addr);
|
|
|
632
|
|
|
633 /* Now reset the ld.so symbol table. */
|
|
|
634 if (dynamic_addr)
|
|
|
635 {
|
|
|
636 struct translation_struct ts;
|
|
|
637 struct relocation_info *tmp, *end;
|
|
|
638 caddr_t syms, strings;
|
|
|
639
|
|
|
640 /* set up the structure that we use to translate addresses in the
|
|
|
641 old file into file offsets */
|
|
|
642 ts.txtaddr = N_TXTADDR (old_hdr);
|
|
|
643 ts.txtoff = N_TXTOFF (old_hdr);
|
|
|
644 ts.dataddr = N_DATADDR (old_hdr);
|
|
|
645 ts.datoff = N_DATOFF (old_hdr);
|
|
|
646 ts.bssaddr = N_DATADDR (old_hdr) + old_hdr.a_data;
|
|
|
647 ts.endaddr = ts.bssaddr + old_hdr.a_bss;
|
|
|
648
|
|
|
649 syms = new_base_addr + unexec_addr_to_offset(ld2->sdt_nzlist, &ts);
|
|
|
650 strings = new_base_addr + unexec_addr_to_offset(ld2->sdt_strings, &ts);
|
|
|
651 reset_ldso_symtab ((struct nzlist *) syms, (struct nzlist *) strings,
|
|
|
652 (char *) strings,
|
|
|
653 new_edata, new_edata,
|
|
|
654 !!dynamic_addr);
|
|
|
655
|
|
|
656 /* STEP 2 */
|
|
|
657 tmp = (struct relocation_info *)
|
|
|
658 (old_base_addr + unexec_addr_to_offset(ld2->sdt_rel, &ts));
|
|
|
659 end = (struct relocation_info *)
|
|
|
660 (old_base_addr + unexec_addr_to_offset(ld2->sdt_hash, &ts));
|
|
|
661 while (tmp < end)
|
|
|
662 {
|
|
|
663 copy_relocation_site (tmp, old_base_addr, new_base_addr, &ts);
|
|
|
664 tmp++;
|
|
|
665 }
|
|
|
666 }
|
|
|
667
|
|
|
668 /* get rid of the mmap-ed file space and make the output file
|
|
|
669 executable -- then quit */
|
|
|
670 munmap (new_base_addr, MASK_UP (new_buf.st_size, page_size));
|
|
|
671 munmap (old_base_addr, MASK_UP (old_buf.st_size, page_size));
|
|
|
672 unexec_fchmod (new_fd, 0755);
|
|
|
673 close (new_fd);
|
|
|
674 return 0;
|
|
|
675 }
|
|
|
676
|
|
|
677
|
|
|
678 int
|
|
|
679 run_time_remap (char *dummy)
|
|
|
680 {
|
|
|
681 unsigned long current_sbrk = (unsigned long) sbrk (0);
|
|
|
682
|
|
|
683 #if __FreeBSD_version < 300000 /* 2.x can work with this code */
|
|
|
684 if (sbrk_of_0_at_unexec < current_sbrk)
|
|
|
685 {
|
|
|
686 if (sbrk_of_0_at_unexec != 0)
|
|
|
687 fprintf (stderr, "Absurd new brk addr = %lx (current = %lx)\n",
|
|
|
688 sbrk_of_0_at_unexec, current_sbrk);
|
|
|
689 }
|
|
|
690 else
|
|
|
691 #endif
|
|
|
692 if (sbrk_of_0_at_unexec > current_sbrk)
|
|
|
693 {
|
|
|
694 errno = 0;
|
|
|
695 if (brk ((caddr_t) sbrk_of_0_at_unexec))
|
|
|
696 fprintf (stderr, "failed to change brk addr to %lx: %s\n",
|
|
|
697 sbrk_of_0_at_unexec, SYS_ERR);
|
|
|
698 }
|
|
|
699
|
|
|
700 #if 0
|
|
|
701 /* with proper COW, i don't think we really need to do this... */
|
|
|
702 {
|
|
|
703 long page_size = getpagesize();
|
|
|
704 unsigned long base_addr = MASK_UP (mprotect_bottom_addr, page_size);
|
|
|
705 unsigned long top_addr = MASK_DOWN (mprotect_top_addr, page_size);
|
|
|
706 long len = top_addr - base_addr;
|
|
|
707
|
|
|
708 if (len > 0)
|
|
|
709 {
|
|
|
710 errno = 0;
|
|
|
711 if (mprotect ((caddr_t) base_addr, len, PROT_READ | PROT_EXEC))
|
|
|
712 fprintf (stderr, "failed to change protection on data pages: %s\n",
|
|
|
713 SYS_ERR);
|
|
|
714 }
|
|
|
715 }
|
|
|
716 #endif
|
|
|
717
|
|
|
718 return 0;
|
|
|
719 }
|
