src/unexelf.c

   1 /* Copyright (C) 1985, 1986, 1987, 1988 Free Software Foundation, Inc.
   2
   3                        NO WARRANTY
   4
   5   BECAUSE THIS PROGRAM IS LICENSED FREE OF CHARGE, WE PROVIDE ABSOLUTELY
   6 NO WARRANTY, TO THE EXTENT PERMITTED BY APPLICABLE STATE LAW.  EXCEPT
   7 WHEN OTHERWISE STATED IN WRITING, FREE SOFTWARE FOUNDATION, INC,
   8 RICHARD M. STALLMAN AND/OR OTHER PARTIES PROVIDE THIS PROGRAM "AS IS"
   9 WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING,
  10 BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
  11 FITNESS FOR A PARTICULAR PURPOSE.  THE ENTIRE RISK AS TO THE QUALITY
  12 AND PERFORMANCE OF THE PROGRAM IS WITH YOU.  SHOULD THE PROGRAM PROVE
  13 DEFECTIVE, YOU ASSUME THE COST OF ALL NECESSARY SERVICING, REPAIR OR
  14 CORRECTION.
  15
  16  IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW WILL RICHARD M.
  17 STALLMAN, THE FREE SOFTWARE FOUNDATION, INC., AND/OR ANY OTHER PARTY
  18 WHO MAY MODIFY AND REDISTRIBUTE THIS PROGRAM AS PERMITTED BELOW, BE
  19 LIABLE TO YOU FOR DAMAGES, INCLUDING ANY LOST PROFITS, LOST MONIES, OR
  20 OTHER SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING OUT OF THE
  21 USE OR INABILITY TO USE (INCLUDING BUT NOT LIMITED TO LOSS OF DATA OR
  22 DATA BEING RENDERED INACCURATE OR LOSSES SUSTAINED BY THIRD PARTIES OR
  23 A FAILURE OF THE PROGRAM TO OPERATE WITH ANY OTHER PROGRAMS) THIS
  24 PROGRAM, EVEN IF YOU HAVE BEEN ADVISED OF THE POSSIBILITY OF SUCH
  25 DAMAGES, OR FOR ANY CLAIM BY ANY OTHER PARTY.
  26
  27                 GENERAL PUBLIC LICENSE TO COPY
  28
  29   1. You may copy and distribute verbatim copies of this source file
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  32 (C) 1987 Free Software Foundation, Inc."; and include following the
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  36
  37   2. You may modify your copy or copies of this source file or
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  45     that in whole or in part contains or is a derivative of this
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  50
  51     c) You may charge a distribution fee for the physical act of
  52     transferring a copy, and you may at your option offer warranty
  53     protection in exchange for a fee.
  54
  55 Mere aggregation of another unrelated program with this program (or its
  56 derivative) on a volume of a storage or distribution medium does not bring
  57 the other program under the scope of these terms.
  58
  59   3. You may copy and distribute this program (or a portion or derivative
  60 of it, under Paragraph 2) in object code or executable form under the terms
  61 of Paragraphs 1 and 2 above provided that you also do one of the following:
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  63     a) accompany it with the complete corresponding machine-readable
  64     source code, which must be distributed under the terms of
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  74     corresponding source code may be obtained.  (This alternative is
  75     allowed only for noncommercial distribution and only if you
  76     received the program in object code or executable form alone.)
  77
  78 For an executable file, complete source code means all the source code for
  79 all modules it contains; but, as a special exception, it need not include
  80 source code for modules which are standard libraries that accompany the
  81 operating system on which the executable file runs.
  82
  83   4. You may not copy, sublicense, distribute or transfer this program
  84 except as expressly provided under this License Agreement.  Any attempt
  85 otherwise to copy, sublicense, distribute or transfer this program is void and
  86 your rights to use the program under this License agreement shall be
  87 automatically terminated.  However, parties who have received computer
  88 software programs from you with this License Agreement will not have
  89 their licenses terminated so long as such parties remain in full compliance.
  90
  91   5. If you wish to incorporate parts of this program into other free
  92 programs whose distribution conditions are different, write to the Free
  93 Software Foundation at 675 Mass Ave, Cambridge, MA 02139.  We have not yet
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  98
  99
 100 In other words, you are welcome to use, share and improve this program.
 101 You are forbidden to forbid anyone else to use, share and improve
 102 what you give them.   Help stamp out software-hoarding!  */
 103
 104
 105 /*
 106  * unexec.c - Convert a running program into an a.out file.
 107  *
 108  * Author:      Spencer W. Thomas
 109  *              Computer Science Dept.
 110  *              University of Utah
 111  * Date:        Tue Mar  2 1982
 112  * Modified heavily since then.
 113  *
 114  * Synopsis:
 115  *      unexec (new_name, a_name, data_start, bss_start, entry_address)
 116  *      char *new_name, *a_name;
 117  *      unsigned data_start, bss_start, entry_address;
 118  *
 119  * Takes a snapshot of the program and makes an a.out format file in the
 120  * file named by the string argument new_name.
 121  * If a_name is non-NULL, the symbol table will be taken from the given file.
 122  * On some machines, an existing a_name file is required.
 123  *
 124  * The boundaries within the a.out file may be adjusted with the data_start
 125  * and bss_start arguments.  Either or both may be given as 0 for defaults.
 126  *
 127  * Data_start gives the boundary between the text segment and the data
 128  * segment of the program.  The text segment can contain shared, read-only
 129  * program code and literal data, while the data segment is always unshared
 130  * and unprotected.  Data_start gives the lowest unprotected address.
 131  * The value you specify may be rounded down to a suitable boundary
 132  * as required by the machine you are using.
 133  *
 134  * Specifying zero for data_start means the boundary between text and data
 135  * should not be the same as when the program was loaded.
 136  * If NO_REMAP is defined, the argument data_start is ignored and the
 137  * segment boundaries are never changed.
 138  *
 139  * Bss_start indicates how much of the data segment is to be saved in the
 140  * a.out file and restored when the program is executed.  It gives the lowest
 141  * unsaved address, and is rounded up to a page boundary.  The default when 0
 142  * is given assumes that the entire data segment is to be stored, including
 143  * the previous data and bss as well as any additional storage allocated with
 144  * break (2).
 145  *
 146  * The new file is set up to start at entry_address.
 147  *
 148  * If you make improvements I'd like to get them too.
 149  * harpo!utah-cs!thomas, thomas@Utah-20
 150  *
 151  */
 152
 153 /* Even more heavily modified by james@bigtex.cactus.org of Dell Computer Co.
 154  * ELF support added.
 155  *
 156  * Basic theory: the data space of the running process needs to be
 157  * dumped to the output file.  Normally we would just enlarge the size
 158  * of .data, scooting everything down.  But we can't do that in ELF,
 159  * because there is often something between the .data space and the
 160  * .bss space.
 161  *
 162  * In the temacs dump below, notice that the Global Offset Table
 163  * (.got) and the Dynamic link data (.dynamic) come between .data1 and
 164  * .bss.  It does not work to overlap .data with these fields.
 165  *
 166  * The solution is to create a new .data segment.  This segment is
 167  * filled with data from the current process.  Since the contents of
 168  * various sections refer to sections by index, the new .data segment
 169  * is made the last in the table to avoid changing any existing index.
 170
 171  * This is an example of how the section headers are changed.  "Addr"
 172  * is a process virtual address.  "Offset" is a file offset.
 173
 174 raid:/nfs/raid/src/dist-18.56/src> dump -h temacs
 175
 176 temacs:
 177
 178            **** SECTION HEADER TABLE ****
 179 [No]    Type    Flags   Addr         Offset       Size          Name
 180         Link    Info    Adralgn      Entsize
 181
 182 [1]     1       2       0x80480d4    0xd4         0x13          .interp
 183         0       0       0x1          0
 184
 185 [2]     5       2       0x80480e8    0xe8         0x388         .hash
 186         3       0       0x4          0x4
 187
 188 [3]     11      2       0x8048470    0x470        0x7f0         .dynsym
 189         4       1       0x4          0x10
 190
 191 [4]     3       2       0x8048c60    0xc60        0x3ad         .dynstr
 192         0       0       0x1          0
 193
 194 [5]     9       2       0x8049010    0x1010       0x338         .rel.plt
 195         3       7       0x4          0x8
 196
 197 [6]     1       6       0x8049348    0x1348       0x3           .init
 198         0       0       0x4          0
 199
 200 [7]     1       6       0x804934c    0x134c       0x680         .plt
 201         0       0       0x4          0x4
 202
 203 [8]     1       6       0x80499cc    0x19cc       0x3c56f       .text
 204         0       0       0x4          0
 205
 206 [9]     1       6       0x8085f3c    0x3df3c      0x3           .fini
 207         0       0       0x4          0
 208
 209 [10]    1       2       0x8085f40    0x3df40      0x69c         .rodata
 210         0       0       0x4          0
 211
 212 [11]    1       2       0x80865dc    0x3e5dc      0xd51         .rodata1
 213         0       0       0x4          0
 214
 215 [12]    1       3       0x8088330    0x3f330      0x20afc       .data
 216         0       0       0x4          0
 217
 218 [13]    1       3       0x80a8e2c    0x5fe2c      0x89d         .data1
 219         0       0       0x4          0
 220
 221 [14]    1       3       0x80a96cc    0x606cc      0x1a8         .got
 222         0       0       0x4          0x4
 223
 224 [15]    6       3       0x80a9874    0x60874      0x80          .dynamic
 225         4       0       0x4          0x8
 226
 227 [16]    8       3       0x80a98f4    0x608f4      0x449c        .bss
 228         0       0       0x4          0
 229
 230 [17]    2       0       0            0x608f4      0x9b90        .symtab
 231         18      371     0x4          0x10
 232
 233 [18]    3       0       0            0x6a484      0x8526        .strtab
 234         0       0       0x1          0
 235
 236 [19]    3       0       0            0x729aa      0x93          .shstrtab
 237         0       0       0x1          0
 238
 239 [20]    1       0       0            0x72a3d      0x68b7        .comment
 240         0       0       0x1          0
 241
 242 raid:/nfs/raid/src/dist-18.56/src> dump -h xemacs
 243
 244 xemacs:
 245
 246            **** SECTION HEADER TABLE ****
 247 [No]    Type    Flags   Addr         Offset       Size          Name
 248         Link    Info    Adralgn      Entsize
 249
 250 [1]     1       2       0x80480d4    0xd4         0x13          .interp
 251         0       0       0x1          0
 252
 253 [2]     5       2       0x80480e8    0xe8         0x388         .hash
 254         3       0       0x4          0x4
 255
 256 [3]     11      2       0x8048470    0x470        0x7f0         .dynsym
 257         4       1       0x4          0x10
 258
 259 [4]     3       2       0x8048c60    0xc60        0x3ad         .dynstr
 260         0       0       0x1          0
 261
 262 [5]     9       2       0x8049010    0x1010       0x338         .rel.plt
 263         3       7       0x4          0x8
 264
 265 [6]     1       6       0x8049348    0x1348       0x3           .init
 266         0       0       0x4          0
 267
 268 [7]     1       6       0x804934c    0x134c       0x680         .plt
 269         0       0       0x4          0x4
 270
 271 [8]     1       6       0x80499cc    0x19cc       0x3c56f       .text
 272         0       0       0x4          0
 273
 274 [9]     1       6       0x8085f3c    0x3df3c      0x3           .fini
 275         0       0       0x4          0
 276
 277 [10]    1       2       0x8085f40    0x3df40      0x69c         .rodata
 278         0       0       0x4          0
 279
 280 [11]    1       2       0x80865dc    0x3e5dc      0xd51         .rodata1
 281         0       0       0x4          0
 282
 283 [12]    1       3       0x8088330    0x3f330      0x20afc       .data
 284         0       0       0x4          0
 285
 286 [13]    1       3       0x80a8e2c    0x5fe2c      0x89d         .data1
 287         0       0       0x4          0
 288
 289 [14]    1       3       0x80a96cc    0x606cc      0x1a8         .got
 290         0       0       0x4          0x4
 291
 292 [15]    6       3       0x80a9874    0x60874      0x80          .dynamic
 293         4       0       0x4          0x8
 294
 295 [16]    8       3       0x80c6800    0x7d800      0             .bss
 296         0       0       0x4          0
 297
 298 [17]    2       0       0            0x7d800      0x9b90        .symtab
 299         18      371     0x4          0x10
 300
 301 [18]    3       0       0            0x87390      0x8526        .strtab
 302         0       0       0x1          0
 303
 304 [19]    3       0       0            0x8f8b6      0x93          .shstrtab
 305         0       0       0x1          0
 306
 307 [20]    1       0       0            0x8f949      0x68b7        .comment
 308         0       0       0x1          0
 309
 310 [21]    1       3       0x80a98f4    0x608f4      0x1cf0c       .data
 311         0       0       0x4          0
 312
 313  * This is an example of how the file header is changed.  "Shoff" is
 314  * the section header offset within the file.  Since that table is
 315  * after the new .data section, it is moved.  "Shnum" is the number of
 316  * sections, which we increment.
 317  *
 318  * "Phoff" is the file offset to the program header.  "Phentsize" and
 319  * "Shentsz" are the program and section header entries sizes respectively.
 320  * These can be larger than the apparent struct sizes.
 321
 322 raid:/nfs/raid/src/dist-18.56/src> dump -f temacs
 323
 324 temacs:
 325
 326                     **** ELF HEADER ****
 327 Class        Data       Type         Machine     Version
 328 Entry        Phoff      Shoff        Flags       Ehsize
 329 Phentsize    Phnum      Shentsz      Shnum       Shstrndx
 330
 331 1            1          2            3           1
 332 0x80499cc    0x34       0x792f4      0           0x34
 333 0x20         5          0x28         21          19
 334
 335 raid:/nfs/raid/src/dist-18.56/src> dump -f xemacs
 336
 337 xemacs:
 338
 339                     **** ELF HEADER ****
 340 Class        Data       Type         Machine     Version
 341 Entry        Phoff      Shoff        Flags       Ehsize
 342 Phentsize    Phnum      Shentsz      Shnum       Shstrndx
 343
 344 1            1          2            3           1
 345 0x80499cc    0x34       0x96200      0           0x34
 346 0x20         5          0x28         22          19
 347
 348  * These are the program headers.  "Offset" is the file offset to the
 349  * segment.  "Vaddr" is the memory load address.  "Filesz" is the
 350  * segment size as it appears in the file, and "Memsz" is the size in
 351  * memory.  Below, the third segment is the code and the fourth is the
 352  * data: the difference between Filesz and Memsz is .bss
 353
 354 raid:/nfs/raid/src/dist-18.56/src> dump -o temacs
 355
 356 temacs:
 357  ***** PROGRAM EXECUTION HEADER *****
 358 Type        Offset      Vaddr       Paddr
 359 Filesz      Memsz       Flags       Align
 360
 361 6           0x34        0x8048034   0
 362 0xa0        0xa0        5           0
 363
 364 3           0xd4        0           0
 365 0x13        0           4           0
 366
 367 1           0x34        0x8048034   0
 368 0x3f2f9     0x3f2f9     5           0x1000
 369
 370 1           0x3f330     0x8088330   0
 371 0x215c4     0x25a60     7           0x1000
 372
 373 2           0x60874     0x80a9874   0
 374 0x80        0           7           0
 375
 376 raid:/nfs/raid/src/dist-18.56/src> dump -o xemacs
 377
 378 xemacs:
 379  ***** PROGRAM EXECUTION HEADER *****
 380 Type        Offset      Vaddr       Paddr
 381 Filesz      Memsz       Flags       Align
 382
 383 6           0x34        0x8048034   0
 384 0xa0        0xa0        5           0
 385
 386 3           0xd4        0           0
 387 0x13        0           4           0
 388
 389 1           0x34        0x8048034   0
 390 0x3f2f9     0x3f2f9     5           0x1000
 391
 392 1           0x3f330     0x8088330   0
 393 0x3e4d0     0x3e4d0     7           0x1000
 394
 395 2           0x60874     0x80a9874   0
 396 0x80        0           7           0
 397
 398
 399  */
 400
 401 #include <sys/types.h>
 402 #include <stdio.h>
 403 #include <sys/stat.h>
 404 #include <memory.h>
 405 #include <string.h>
 406 #include <errno.h>
 407 #include <unistd.h>
 408 #include <fcntl.h>
 409 #include <elf.h>
 410 #include <sys/mman.h>
 411
 412 #ifndef emacs
 413 #define fatal(a, b, c) fprintf(stderr, a, b, c), exit(1)
 414 #else
 415 extern void fatal(char *, ...);
 416 #endif
 417
 418 /* Get the address of a particular section or program header entry,
 419  * accounting for the size of the entries.
 420  */
 421
 422 #define OLD_SECTION_H(n) \
 423      (*(Elf32_Shdr *) ((byte *) old_section_h + old_file_h->e_shentsize * (n)))
 424 #define NEW_SECTION_H(n) \
 425      (*(Elf32_Shdr *) ((byte *) new_section_h + new_file_h->e_shentsize * (n)))
 426 #define OLD_PROGRAM_H(n) \
 427      (*(Elf32_Phdr *) ((byte *) old_program_h + old_file_h->e_phentsize * (n)))
 428 #define NEW_PROGRAM_H(n) \
 429      (*(Elf32_Phdr *) ((byte *) new_program_h + new_file_h->e_phentsize * (n)))
 430
 431 typedef unsigned char byte;
 432
 433 /* ****************************************************************
 434  * unexec
 435  *
 436  * driving logic.
 437  *
 438  * In ELF, this works by replacing the old .bss section with a new
 439  * .data section, and inserting an empty .bss immediately afterwards.
 440  *
 441  */
 442 void
 443 unexec (new_name, old_name, data_start, bss_start, entry_address)
 444      char *new_name, *old_name;
 445      unsigned data_start, bss_start, entry_address;
 446 {
 447   extern unsigned int bss_end;
 448   int new_file, old_file, new_file_size;
 449
 450   /* Pointers to the base of the image of the two files. */
 451   caddr_t old_base, new_base;
 452
 453   /* Pointers to the file, program and section headers for the old and new
 454    * files.
 455    */
 456   Elf32_Ehdr *old_file_h, *new_file_h;
 457   Elf32_Phdr *old_program_h, *new_program_h;
 458   Elf32_Shdr *old_section_h, *new_section_h;
 459
 460   /* Point to the section name table in the old file */
 461   char *old_section_names;
 462
 463   Elf32_Addr old_bss_addr, new_bss_addr;
 464   Elf32_Word old_bss_size, new_data2_size;
 465   Elf32_Off  new_data2_offset;
 466   Elf32_Addr new_data2_addr;
 467
 468   int n, old_bss_index, old_data_index, new_data2_index;
 469   struct stat stat_buf;
 470
 471   /* Open the old file & map it into the address space. */
 472
 473   old_file = open (old_name, O_RDONLY);
 474
 475   if (old_file < 0)
 476     fatal ("Can't open %s for reading: errno %d\n", old_name, errno);
 477
 478   if (fstat (old_file, &stat_buf) == -1)
 479     fatal ("Can't fstat(%s): errno %d\n", old_name, errno);
 480
 481   old_base = mmap (0, stat_buf.st_size, PROT_READ, MAP_SHARED, old_file, 0);
 482
 483   if (old_base == (caddr_t) -1)
 484     fatal ("Can't mmap(%s): errno %d\n", old_name, errno);
 485
 486 #ifdef DEBUG
 487   fprintf (stderr, "mmap(%s, %x) -> %x\n", old_name, stat_buf.st_size,
 488            old_base);
 489 #endif
 490
 491   /* Get pointers to headers & section names */
 492
 493   old_file_h = (Elf32_Ehdr *) old_base;
 494   old_program_h = (Elf32_Phdr *) ((byte *) old_base + old_file_h->e_phoff);
 495   old_section_h = (Elf32_Shdr *) ((byte *) old_base + old_file_h->e_shoff);
 496   old_section_names = (char *) old_base
 497     + OLD_SECTION_H(old_file_h->e_shstrndx).sh_offset;
 498
 499   /* Find the old .bss section.  Figure out parameters of the new
 500    * data2 and bss sections.
 501    */
 502
 503   for (old_bss_index = 1; old_bss_index < old_file_h->e_shnum; old_bss_index++)
 504     {
 505 #ifdef DEBUG
 506       fprintf (stderr, "Looking for .bss - found %s\n",
 507                old_section_names + OLD_SECTION_H(old_bss_index).sh_name);
 508 #endif
 509       if (!strcmp (old_section_names + OLD_SECTION_H(old_bss_index).sh_name,
 510                    ".bss"))
 511         break;
 512     }
 513   if (old_bss_index == old_file_h->e_shnum)
 514     fatal ("Can't find .bss in %s.\n", old_name, 0);
 515
 516   old_bss_addr = OLD_SECTION_H(old_bss_index).sh_addr;
 517   old_bss_size = OLD_SECTION_H(old_bss_index).sh_size;
 518 #if defined(emacs) || !defined(DEBUG)
 519   bss_end = (unsigned int) sbrk (0);
 520   new_bss_addr = (Elf32_Addr) bss_end;
 521 #else
 522   new_bss_addr = old_bss_addr + old_bss_size + 0x1234;
 523 #endif
 524   new_data2_addr = old_bss_addr;
 525   new_data2_size = new_bss_addr - old_bss_addr;
 526   new_data2_offset = OLD_SECTION_H(old_bss_index).sh_offset;
 527
 528 #ifdef DEBUG
 529   fprintf (stderr, "old_bss_index %d\n", old_bss_index);
 530   fprintf (stderr, "old_bss_addr %x\n", old_bss_addr);
 531   fprintf (stderr, "old_bss_size %x\n", old_bss_size);
 532   fprintf (stderr, "new_bss_addr %x\n", new_bss_addr);
 533   fprintf (stderr, "new_data2_addr %x\n", new_data2_addr);
 534   fprintf (stderr, "new_data2_size %x\n", new_data2_size);
 535   fprintf (stderr, "new_data2_offset %x\n", new_data2_offset);
 536 #endif
 537
 538   if ((unsigned) new_bss_addr < (unsigned) old_bss_addr + old_bss_size)
 539     fatal (".bss shrank when undumping???\n", 0, 0);
 540
 541   /* Set the output file to the right size and mmap(2) it.  Set
 542    * pointers to various interesting objects.  stat_buf still has
 543    * old_file data.
 544    */
 545
 546   new_file = open (new_name, O_RDWR | O_CREAT, 0666);
 547   if (new_file < 0)
 548     fatal ("Can't creat(%s): errno %d\n", new_name, errno);
 549
 550   new_file_size = stat_buf.st_size + old_file_h->e_shentsize + new_data2_size;
 551
 552   if (ftruncate (new_file, new_file_size))
 553     fatal ("Can't ftruncate(%s): errno %d\n", new_name, errno);
 554
 555   new_base = mmap (0, new_file_size, PROT_READ | PROT_WRITE, MAP_SHARED,
 556                    new_file, 0);
 557
 558   if (new_base == (caddr_t) -1)
 559     fatal ("Can't mmap(%s): errno %d\n", new_name, errno);
 560
 561   new_file_h = (Elf32_Ehdr *) new_base;
 562   new_program_h = (Elf32_Phdr *) ((byte *) new_base + old_file_h->e_phoff);
 563   new_section_h = (Elf32_Shdr *)
 564     ((byte *) new_base + old_file_h->e_shoff + new_data2_size);
 565
 566   /* Make our new file, program and section headers as copies of the
 567    * originals.
 568    */
 569
 570   memcpy (new_file_h, old_file_h, old_file_h->e_ehsize);
 571   memcpy (new_program_h, old_program_h,
 572           old_file_h->e_phnum * old_file_h->e_phentsize);
 573   memcpy (new_section_h, old_section_h,
 574           old_file_h->e_shnum * old_file_h->e_shentsize);
 575
 576   /* Fix up file header.  We'll add one section.  Section header is
 577    * further away now.
 578    */
 579
 580   new_file_h->e_shoff += new_data2_size;
 581   new_file_h->e_shnum += 1;
 582
 583 #ifdef DEBUG
 584   fprintf (stderr, "Old section offset %x\n", old_file_h->e_shoff);
 585   fprintf (stderr, "Old section count %d\n", old_file_h->e_shnum);
 586   fprintf (stderr, "New section offset %x\n", new_file_h->e_shoff);
 587   fprintf (stderr, "New section count %d\n", new_file_h->e_shnum);
 588 #endif
 589
 590   /* Fix up a new program header.  Extend the writable data segment so
 591    * that the bss area is covered too. Find that segment by looking
 592    * for a segment that ends just before the .bss area.  Make sure
 593    * that no segments are above the new .data2.  Put a loop at the end
 594    * to adjust the offset and address of any segment that is above
 595    * data2, just in case we decide to allow this later.
 596    */
 597
 598   for (n = new_file_h->e_phnum - 1; n >= 0; n--)
 599     {
 600       if (NEW_PROGRAM_H(n).p_vaddr + NEW_PROGRAM_H(n).p_filesz > old_bss_addr)
 601         fatal ("Program segment above .bss in %s\n", old_name, 0);
 602
 603       if (NEW_PROGRAM_H(n).p_type == PT_LOAD
 604           && (NEW_PROGRAM_H(n).p_vaddr + NEW_PROGRAM_H(n).p_filesz
 605               == old_bss_addr))
 606         break;
 607     }
 608   if (n < 0)
 609     fatal ("Couldn't find segment next to .bss in %s\n", old_name, 0);
 610
 611   NEW_PROGRAM_H(n).p_filesz += new_data2_size;
 612   NEW_PROGRAM_H(n).p_memsz = NEW_PROGRAM_H(n).p_filesz;
 613
 614 #if 0 /* Maybe allow section after data2 - does this ever happen? */
 615   for (n = new_file_h->e_phnum - 1; n >= 0; n--)
 616     {
 617       if (NEW_PROGRAM_H(n).p_vaddr
 618           && NEW_PROGRAM_H(n).p_vaddr >= new_data2_addr)
 619         NEW_PROGRAM_H(n).p_vaddr += new_data2_size - old_bss_size;
 620
 621       if (NEW_PROGRAM_H(n).p_offset >= new_data2_offset)
 622         NEW_PROGRAM_H(n).p_offset += new_data2_size;
 623     }
 624 #endif
 625
 626   /* Fix up section headers based on new .data2 section.  Any section
 627    * whose offset or virtual address is after the new .data2 section
 628    * gets its value adjusted.  .bss size becomes zero and new address
 629    * is set.  data2 section header gets added by copying the existing
 630    * .data header and modifying the offset, address and size.
 631    */
 632
 633   for (n = 1; n < new_file_h->e_shnum; n++)
 634     {
 635       if (NEW_SECTION_H(n).sh_offset >= new_data2_offset)
 636         NEW_SECTION_H(n).sh_offset += new_data2_size;
 637
 638       if (NEW_SECTION_H(n).sh_addr
 639           && NEW_SECTION_H(n).sh_addr >= new_data2_addr)
 640         NEW_SECTION_H(n).sh_addr += new_data2_size - old_bss_size;
 641     }
 642
 643   new_data2_index = old_file_h->e_shnum;
 644
 645   for (old_data_index = 1; old_data_index < old_file_h->e_shnum;
 646        old_data_index++)
 647     if (!strcmp (old_section_names + OLD_SECTION_H(old_data_index).sh_name,
 648                  ".data"))
 649       break;
 650   if (old_data_index == old_file_h->e_shnum)
 651     fatal ("Can't find .data in %s.\n", old_name, 0);
 652
 653   memcpy (&NEW_SECTION_H(new_data2_index), &OLD_SECTION_H(old_data_index),
 654           new_file_h->e_shentsize);
 655
 656   NEW_SECTION_H(new_data2_index).sh_addr = new_data2_addr;
 657   NEW_SECTION_H(new_data2_index).sh_offset = new_data2_offset;
 658   NEW_SECTION_H(new_data2_index).sh_size = new_data2_size;
 659
 660   NEW_SECTION_H(old_bss_index).sh_size = 0;
 661   NEW_SECTION_H(old_bss_index).sh_addr = new_data2_addr + new_data2_size;
 662
 663   /* Write out the sections. .data and .data1 (and data2, called
 664    * ".data" in the strings table) get copied from the current process
 665    * instead of the old file.
 666    */
 667
 668   for (n = new_file_h->e_shnum - 1; n; n--)
 669     {
 670       caddr_t src;
 671
 672       if (NEW_SECTION_H(n).sh_type == SHT_NULL
 673           || NEW_SECTION_H(n).sh_type == SHT_NOBITS)
 674         continue;
 675
 676       if (!strcmp (old_section_names + NEW_SECTION_H(n).sh_name, ".data")
 677           || !strcmp ((old_section_names + NEW_SECTION_H(n).sh_name),
 678                       ".data1"))
 679         src = (caddr_t) NEW_SECTION_H(n).sh_addr;
 680       else
 681         src = old_base + OLD_SECTION_H(n).sh_offset;
 682
 683       memcpy (NEW_SECTION_H(n).sh_offset + new_base, src,
 684               NEW_SECTION_H(n).sh_size);
 685     }
 686
 687   /* Close the files and make the new file executable */
 688
 689   if (close (old_file))
 690     fatal ("Can't close(%s): errno %d\n", old_name, errno);
 691
 692   if (close (new_file))
 693     fatal ("Can't close(%s): errno %d\n", new_name, errno);
 694
 695   if (stat (new_name, &stat_buf) == -1)
 696     fatal ("Can't stat(%s): errno %d\n", new_name, errno);
 697
 698   n = umask (777);
 699   umask (n);
 700   stat_buf.st_mode |= 0111 & ~n;
 701   if (chmod (new_name, stat_buf.st_mode) == -1)
 702     fatal ("Can't chmod(%s): errno %d\n", new_name, errno);
 703 }