| 1 | /* Copyright (C) 1985-1988, 1990, 1992, 1999-2014 Free Software |
| 2 | Foundation, Inc. |
| 3 | |
| 4 | This file is part of GNU Emacs. |
| 5 | |
| 6 | GNU Emacs is free software: you can redistribute it and/or modify |
| 7 | it under the terms of the GNU General Public License as published by |
| 8 | the Free Software Foundation, either version 3 of the License, or |
| 9 | (at your option) any later version. |
| 10 | |
| 11 | GNU Emacs is distributed in the hope that it will be useful, |
| 12 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 13 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 14 | GNU General Public License for more details. |
| 15 | |
| 16 | You should have received a copy of the GNU General Public License |
| 17 | along with GNU Emacs. If not, see <http://www.gnu.org/licenses/>. */ |
| 18 | |
| 19 | /* |
| 20 | In other words, you are welcome to use, share and improve this program. |
| 21 | You are forbidden to forbid anyone else to use, share and improve |
| 22 | what you give them. Help stamp out software-hoarding! */ |
| 23 | |
| 24 | |
| 25 | /* |
| 26 | * unexec.c - Convert a running program into an a.out file. |
| 27 | * |
| 28 | * Author: Spencer W. Thomas |
| 29 | * Computer Science Dept. |
| 30 | * University of Utah |
| 31 | * Date: Tue Mar 2 1982 |
| 32 | * Modified heavily since then. |
| 33 | * |
| 34 | * Synopsis: |
| 35 | * unexec (const char *new_name, const char *old_name); |
| 36 | * |
| 37 | * Takes a snapshot of the program and makes an a.out format file in the |
| 38 | * file named by the string argument new_name. |
| 39 | * If old_name is non-NULL, the symbol table will be taken from the given file. |
| 40 | * On some machines, an existing old_name file is required. |
| 41 | * |
| 42 | */ |
| 43 | |
| 44 | /* Even more heavily modified by james@bigtex.cactus.org of Dell Computer Co. |
| 45 | * ELF support added. |
| 46 | * |
| 47 | * Basic theory: the data space of the running process needs to be |
| 48 | * dumped to the output file. Normally we would just enlarge the size |
| 49 | * of .data, scooting everything down. But we can't do that in ELF, |
| 50 | * because there is often something between the .data space and the |
| 51 | * .bss space. |
| 52 | * |
| 53 | * In the temacs dump below, notice that the Global Offset Table |
| 54 | * (.got) and the Dynamic link data (.dynamic) come between .data1 and |
| 55 | * .bss. It does not work to overlap .data with these fields. |
| 56 | * |
| 57 | * The solution is to create a new .data segment. This segment is |
| 58 | * filled with data from the current process. Since the contents of |
| 59 | * various sections refer to sections by index, the new .data segment |
| 60 | * is made the last in the table to avoid changing any existing index. |
| 61 | |
| 62 | * This is an example of how the section headers are changed. "Addr" |
| 63 | * is a process virtual address. "Offset" is a file offset. |
| 64 | |
| 65 | raid:/nfs/raid/src/dist-18.56/src> dump -h temacs |
| 66 | |
| 67 | temacs: |
| 68 | |
| 69 | **** SECTION HEADER TABLE **** |
| 70 | [No] Type Flags Addr Offset Size Name |
| 71 | Link Info Adralgn Entsize |
| 72 | |
| 73 | [1] 1 2 0x80480d4 0xd4 0x13 .interp |
| 74 | 0 0 0x1 0 |
| 75 | |
| 76 | [2] 5 2 0x80480e8 0xe8 0x388 .hash |
| 77 | 3 0 0x4 0x4 |
| 78 | |
| 79 | [3] 11 2 0x8048470 0x470 0x7f0 .dynsym |
| 80 | 4 1 0x4 0x10 |
| 81 | |
| 82 | [4] 3 2 0x8048c60 0xc60 0x3ad .dynstr |
| 83 | 0 0 0x1 0 |
| 84 | |
| 85 | [5] 9 2 0x8049010 0x1010 0x338 .rel.plt |
| 86 | 3 7 0x4 0x8 |
| 87 | |
| 88 | [6] 1 6 0x8049348 0x1348 0x3 .init |
| 89 | 0 0 0x4 0 |
| 90 | |
| 91 | [7] 1 6 0x804934c 0x134c 0x680 .plt |
| 92 | 0 0 0x4 0x4 |
| 93 | |
| 94 | [8] 1 6 0x80499cc 0x19cc 0x3c56f .text |
| 95 | 0 0 0x4 0 |
| 96 | |
| 97 | [9] 1 6 0x8085f3c 0x3df3c 0x3 .fini |
| 98 | 0 0 0x4 0 |
| 99 | |
| 100 | [10] 1 2 0x8085f40 0x3df40 0x69c .rodata |
| 101 | 0 0 0x4 0 |
| 102 | |
| 103 | [11] 1 2 0x80865dc 0x3e5dc 0xd51 .rodata1 |
| 104 | 0 0 0x4 0 |
| 105 | |
| 106 | [12] 1 3 0x8088330 0x3f330 0x20afc .data |
| 107 | 0 0 0x4 0 |
| 108 | |
| 109 | [13] 1 3 0x80a8e2c 0x5fe2c 0x89d .data1 |
| 110 | 0 0 0x4 0 |
| 111 | |
| 112 | [14] 1 3 0x80a96cc 0x606cc 0x1a8 .got |
| 113 | 0 0 0x4 0x4 |
| 114 | |
| 115 | [15] 6 3 0x80a9874 0x60874 0x80 .dynamic |
| 116 | 4 0 0x4 0x8 |
| 117 | |
| 118 | [16] 8 3 0x80a98f4 0x608f4 0x449c .bss |
| 119 | 0 0 0x4 0 |
| 120 | |
| 121 | [17] 2 0 0 0x608f4 0x9b90 .symtab |
| 122 | 18 371 0x4 0x10 |
| 123 | |
| 124 | [18] 3 0 0 0x6a484 0x8526 .strtab |
| 125 | 0 0 0x1 0 |
| 126 | |
| 127 | [19] 3 0 0 0x729aa 0x93 .shstrtab |
| 128 | 0 0 0x1 0 |
| 129 | |
| 130 | [20] 1 0 0 0x72a3d 0x68b7 .comment |
| 131 | 0 0 0x1 0 |
| 132 | |
| 133 | raid:/nfs/raid/src/dist-18.56/src> dump -h xemacs |
| 134 | |
| 135 | xemacs: |
| 136 | |
| 137 | **** SECTION HEADER TABLE **** |
| 138 | [No] Type Flags Addr Offset Size Name |
| 139 | Link Info Adralgn Entsize |
| 140 | |
| 141 | [1] 1 2 0x80480d4 0xd4 0x13 .interp |
| 142 | 0 0 0x1 0 |
| 143 | |
| 144 | [2] 5 2 0x80480e8 0xe8 0x388 .hash |
| 145 | 3 0 0x4 0x4 |
| 146 | |
| 147 | [3] 11 2 0x8048470 0x470 0x7f0 .dynsym |
| 148 | 4 1 0x4 0x10 |
| 149 | |
| 150 | [4] 3 2 0x8048c60 0xc60 0x3ad .dynstr |
| 151 | 0 0 0x1 0 |
| 152 | |
| 153 | [5] 9 2 0x8049010 0x1010 0x338 .rel.plt |
| 154 | 3 7 0x4 0x8 |
| 155 | |
| 156 | [6] 1 6 0x8049348 0x1348 0x3 .init |
| 157 | 0 0 0x4 0 |
| 158 | |
| 159 | [7] 1 6 0x804934c 0x134c 0x680 .plt |
| 160 | 0 0 0x4 0x4 |
| 161 | |
| 162 | [8] 1 6 0x80499cc 0x19cc 0x3c56f .text |
| 163 | 0 0 0x4 0 |
| 164 | |
| 165 | [9] 1 6 0x8085f3c 0x3df3c 0x3 .fini |
| 166 | 0 0 0x4 0 |
| 167 | |
| 168 | [10] 1 2 0x8085f40 0x3df40 0x69c .rodata |
| 169 | 0 0 0x4 0 |
| 170 | |
| 171 | [11] 1 2 0x80865dc 0x3e5dc 0xd51 .rodata1 |
| 172 | 0 0 0x4 0 |
| 173 | |
| 174 | [12] 1 3 0x8088330 0x3f330 0x20afc .data |
| 175 | 0 0 0x4 0 |
| 176 | |
| 177 | [13] 1 3 0x80a8e2c 0x5fe2c 0x89d .data1 |
| 178 | 0 0 0x4 0 |
| 179 | |
| 180 | [14] 1 3 0x80a96cc 0x606cc 0x1a8 .got |
| 181 | 0 0 0x4 0x4 |
| 182 | |
| 183 | [15] 6 3 0x80a9874 0x60874 0x80 .dynamic |
| 184 | 4 0 0x4 0x8 |
| 185 | |
| 186 | [16] 8 3 0x80c6800 0x7d800 0 .bss |
| 187 | 0 0 0x4 0 |
| 188 | |
| 189 | [17] 2 0 0 0x7d800 0x9b90 .symtab |
| 190 | 18 371 0x4 0x10 |
| 191 | |
| 192 | [18] 3 0 0 0x87390 0x8526 .strtab |
| 193 | 0 0 0x1 0 |
| 194 | |
| 195 | [19] 3 0 0 0x8f8b6 0x93 .shstrtab |
| 196 | 0 0 0x1 0 |
| 197 | |
| 198 | [20] 1 0 0 0x8f949 0x68b7 .comment |
| 199 | 0 0 0x1 0 |
| 200 | |
| 201 | [21] 1 3 0x80a98f4 0x608f4 0x1cf0c .data |
| 202 | 0 0 0x4 0 |
| 203 | |
| 204 | * This is an example of how the file header is changed. "Shoff" is |
| 205 | * the section header offset within the file. Since that table is |
| 206 | * after the new .data section, it is moved. "Shnum" is the number of |
| 207 | * sections, which we increment. |
| 208 | * |
| 209 | * "Phoff" is the file offset to the program header. "Phentsize" and |
| 210 | * "Shentsz" are the program and section header entries sizes respectively. |
| 211 | * These can be larger than the apparent struct sizes. |
| 212 | |
| 213 | raid:/nfs/raid/src/dist-18.56/src> dump -f temacs |
| 214 | |
| 215 | temacs: |
| 216 | |
| 217 | **** ELF HEADER **** |
| 218 | Class Data Type Machine Version |
| 219 | Entry Phoff Shoff Flags Ehsize |
| 220 | Phentsize Phnum Shentsz Shnum Shstrndx |
| 221 | |
| 222 | 1 1 2 3 1 |
| 223 | 0x80499cc 0x34 0x792f4 0 0x34 |
| 224 | 0x20 5 0x28 21 19 |
| 225 | |
| 226 | raid:/nfs/raid/src/dist-18.56/src> dump -f xemacs |
| 227 | |
| 228 | xemacs: |
| 229 | |
| 230 | **** ELF HEADER **** |
| 231 | Class Data Type Machine Version |
| 232 | Entry Phoff Shoff Flags Ehsize |
| 233 | Phentsize Phnum Shentsz Shnum Shstrndx |
| 234 | |
| 235 | 1 1 2 3 1 |
| 236 | 0x80499cc 0x34 0x96200 0 0x34 |
| 237 | 0x20 5 0x28 22 19 |
| 238 | |
| 239 | * These are the program headers. "Offset" is the file offset to the |
| 240 | * segment. "Vaddr" is the memory load address. "Filesz" is the |
| 241 | * segment size as it appears in the file, and "Memsz" is the size in |
| 242 | * memory. Below, the third segment is the code and the fourth is the |
| 243 | * data: the difference between Filesz and Memsz is .bss |
| 244 | |
| 245 | raid:/nfs/raid/src/dist-18.56/src> dump -o temacs |
| 246 | |
| 247 | temacs: |
| 248 | ***** PROGRAM EXECUTION HEADER ***** |
| 249 | Type Offset Vaddr Paddr |
| 250 | Filesz Memsz Flags Align |
| 251 | |
| 252 | 6 0x34 0x8048034 0 |
| 253 | 0xa0 0xa0 5 0 |
| 254 | |
| 255 | 3 0xd4 0 0 |
| 256 | 0x13 0 4 0 |
| 257 | |
| 258 | 1 0x34 0x8048034 0 |
| 259 | 0x3f2f9 0x3f2f9 5 0x1000 |
| 260 | |
| 261 | 1 0x3f330 0x8088330 0 |
| 262 | 0x215c4 0x25a60 7 0x1000 |
| 263 | |
| 264 | 2 0x60874 0x80a9874 0 |
| 265 | 0x80 0 7 0 |
| 266 | |
| 267 | raid:/nfs/raid/src/dist-18.56/src> dump -o xemacs |
| 268 | |
| 269 | xemacs: |
| 270 | ***** PROGRAM EXECUTION HEADER ***** |
| 271 | Type Offset Vaddr Paddr |
| 272 | Filesz Memsz Flags Align |
| 273 | |
| 274 | 6 0x34 0x8048034 0 |
| 275 | 0xa0 0xa0 5 0 |
| 276 | |
| 277 | 3 0xd4 0 0 |
| 278 | 0x13 0 4 0 |
| 279 | |
| 280 | 1 0x34 0x8048034 0 |
| 281 | 0x3f2f9 0x3f2f9 5 0x1000 |
| 282 | |
| 283 | 1 0x3f330 0x8088330 0 |
| 284 | 0x3e4d0 0x3e4d0 7 0x1000 |
| 285 | |
| 286 | 2 0x60874 0x80a9874 0 |
| 287 | 0x80 0 7 0 |
| 288 | |
| 289 | |
| 290 | */ |
| 291 | \f |
| 292 | /* Modified by wtien@urbana.mcd.mot.com of Motorola Inc. |
| 293 | * |
| 294 | * The above mechanism does not work if the unexeced ELF file is being |
| 295 | * re-layout by other applications (such as `strip'). All the applications |
| 296 | * that re-layout the internal of ELF will layout all sections in ascending |
| 297 | * order of their file offsets. After the re-layout, the data2 section will |
| 298 | * still be the LAST section in the section header vector, but its file offset |
| 299 | * is now being pushed far away down, and causes part of it not to be mapped |
| 300 | * in (ie. not covered by the load segment entry in PHDR vector), therefore |
| 301 | * causes the new binary to fail. |
| 302 | * |
| 303 | * The solution is to modify the unexec algorithm to insert the new data2 |
| 304 | * section header right before the new bss section header, so their file |
| 305 | * offsets will be in the ascending order. Since some of the section's (all |
| 306 | * sections AFTER the bss section) indexes are now changed, we also need to |
| 307 | * modify some fields to make them point to the right sections. This is done |
| 308 | * by macro PATCH_INDEX. All the fields that need to be patched are: |
| 309 | * |
| 310 | * 1. ELF header e_shstrndx field. |
| 311 | * 2. section header sh_link and sh_info field. |
| 312 | * 3. symbol table entry st_shndx field. |
| 313 | * |
| 314 | * The above example now should look like: |
| 315 | |
| 316 | **** SECTION HEADER TABLE **** |
| 317 | [No] Type Flags Addr Offset Size Name |
| 318 | Link Info Adralgn Entsize |
| 319 | |
| 320 | [1] 1 2 0x80480d4 0xd4 0x13 .interp |
| 321 | 0 0 0x1 0 |
| 322 | |
| 323 | [2] 5 2 0x80480e8 0xe8 0x388 .hash |
| 324 | 3 0 0x4 0x4 |
| 325 | |
| 326 | [3] 11 2 0x8048470 0x470 0x7f0 .dynsym |
| 327 | 4 1 0x4 0x10 |
| 328 | |
| 329 | [4] 3 2 0x8048c60 0xc60 0x3ad .dynstr |
| 330 | 0 0 0x1 0 |
| 331 | |
| 332 | [5] 9 2 0x8049010 0x1010 0x338 .rel.plt |
| 333 | 3 7 0x4 0x8 |
| 334 | |
| 335 | [6] 1 6 0x8049348 0x1348 0x3 .init |
| 336 | 0 0 0x4 0 |
| 337 | |
| 338 | [7] 1 6 0x804934c 0x134c 0x680 .plt |
| 339 | 0 0 0x4 0x4 |
| 340 | |
| 341 | [8] 1 6 0x80499cc 0x19cc 0x3c56f .text |
| 342 | 0 0 0x4 0 |
| 343 | |
| 344 | [9] 1 6 0x8085f3c 0x3df3c 0x3 .fini |
| 345 | 0 0 0x4 0 |
| 346 | |
| 347 | [10] 1 2 0x8085f40 0x3df40 0x69c .rodata |
| 348 | 0 0 0x4 0 |
| 349 | |
| 350 | [11] 1 2 0x80865dc 0x3e5dc 0xd51 .rodata1 |
| 351 | 0 0 0x4 0 |
| 352 | |
| 353 | [12] 1 3 0x8088330 0x3f330 0x20afc .data |
| 354 | 0 0 0x4 0 |
| 355 | |
| 356 | [13] 1 3 0x80a8e2c 0x5fe2c 0x89d .data1 |
| 357 | 0 0 0x4 0 |
| 358 | |
| 359 | [14] 1 3 0x80a96cc 0x606cc 0x1a8 .got |
| 360 | 0 0 0x4 0x4 |
| 361 | |
| 362 | [15] 6 3 0x80a9874 0x60874 0x80 .dynamic |
| 363 | 4 0 0x4 0x8 |
| 364 | |
| 365 | [16] 1 3 0x80a98f4 0x608f4 0x1cf0c .data |
| 366 | 0 0 0x4 0 |
| 367 | |
| 368 | [17] 8 3 0x80c6800 0x7d800 0 .bss |
| 369 | 0 0 0x4 0 |
| 370 | |
| 371 | [18] 2 0 0 0x7d800 0x9b90 .symtab |
| 372 | 19 371 0x4 0x10 |
| 373 | |
| 374 | [19] 3 0 0 0x87390 0x8526 .strtab |
| 375 | 0 0 0x1 0 |
| 376 | |
| 377 | [20] 3 0 0 0x8f8b6 0x93 .shstrtab |
| 378 | 0 0 0x1 0 |
| 379 | |
| 380 | [21] 1 0 0 0x8f949 0x68b7 .comment |
| 381 | 0 0 0x1 0 |
| 382 | |
| 383 | */ |
| 384 | \f |
| 385 | /* We do not use mmap because that fails with NFS. |
| 386 | Instead we read the whole file, modify it, and write it out. */ |
| 387 | |
| 388 | #include <config.h> |
| 389 | #include "unexec.h" |
| 390 | #include "lisp.h" |
| 391 | |
| 392 | #include <errno.h> |
| 393 | #include <fcntl.h> |
| 394 | #include <limits.h> |
| 395 | #include <memory.h> |
| 396 | #include <stdint.h> |
| 397 | #include <stdio.h> |
| 398 | #include <sys/stat.h> |
| 399 | #include <sys/types.h> |
| 400 | #include <unistd.h> |
| 401 | |
| 402 | #if !defined (__NetBSD__) && !defined (__OpenBSD__) |
| 403 | #include <elf.h> |
| 404 | #endif /* not __NetBSD__ and not __OpenBSD__ */ |
| 405 | #include <sys/mman.h> |
| 406 | #if defined (_SYSTYPE_SYSV) |
| 407 | #include <sys/elf_mips.h> |
| 408 | #include <sym.h> |
| 409 | #endif /* _SYSTYPE_SYSV */ |
| 410 | #if __sgi |
| 411 | #include <syms.h> /* for HDRR declaration */ |
| 412 | #endif /* __sgi */ |
| 413 | |
| 414 | #ifndef MAP_ANON |
| 415 | #ifdef MAP_ANONYMOUS |
| 416 | #define MAP_ANON MAP_ANONYMOUS |
| 417 | #else |
| 418 | #define MAP_ANON 0 |
| 419 | #endif |
| 420 | #endif |
| 421 | |
| 422 | #ifndef MAP_FAILED |
| 423 | #define MAP_FAILED ((void *) -1) |
| 424 | #endif |
| 425 | |
| 426 | #if defined (__alpha__) && !defined (__NetBSD__) && !defined (__OpenBSD__) |
| 427 | /* Declare COFF debugging symbol table. This used to be in |
| 428 | /usr/include/sym.h, but this file is no longer included in Red Hat |
| 429 | 5.0 and presumably in any other glibc 2.x based distribution. */ |
| 430 | typedef struct { |
| 431 | short magic; |
| 432 | short vstamp; |
| 433 | int ilineMax; |
| 434 | int idnMax; |
| 435 | int ipdMax; |
| 436 | int isymMax; |
| 437 | int ioptMax; |
| 438 | int iauxMax; |
| 439 | int issMax; |
| 440 | int issExtMax; |
| 441 | int ifdMax; |
| 442 | int crfd; |
| 443 | int iextMax; |
| 444 | long cbLine; |
| 445 | long cbLineOffset; |
| 446 | long cbDnOffset; |
| 447 | long cbPdOffset; |
| 448 | long cbSymOffset; |
| 449 | long cbOptOffset; |
| 450 | long cbAuxOffset; |
| 451 | long cbSsOffset; |
| 452 | long cbSsExtOffset; |
| 453 | long cbFdOffset; |
| 454 | long cbRfdOffset; |
| 455 | long cbExtOffset; |
| 456 | } HDRR, *pHDRR; |
| 457 | #define cbHDRR sizeof (HDRR) |
| 458 | #define hdrNil ((pHDRR)0) |
| 459 | #endif |
| 460 | |
| 461 | #ifdef __NetBSD__ |
| 462 | /* |
| 463 | * NetBSD does not have normal-looking user-land ELF support. |
| 464 | */ |
| 465 | # if defined __alpha__ || defined __sparc_v9__ || defined _LP64 |
| 466 | # define ELFSIZE 64 |
| 467 | # else |
| 468 | # define ELFSIZE 32 |
| 469 | # endif |
| 470 | # include <sys/exec_elf.h> |
| 471 | |
| 472 | # ifndef PT_LOAD |
| 473 | # define PT_LOAD Elf_pt_load |
| 474 | # if 0 /* was in pkgsrc patches for 20.7 */ |
| 475 | # define SHT_PROGBITS Elf_sht_progbits |
| 476 | # endif |
| 477 | # define SHT_SYMTAB Elf_sht_symtab |
| 478 | # define SHT_DYNSYM Elf_sht_dynsym |
| 479 | # define SHT_NULL Elf_sht_null |
| 480 | # define SHT_NOBITS Elf_sht_nobits |
| 481 | # define SHT_REL Elf_sht_rel |
| 482 | # define SHT_RELA Elf_sht_rela |
| 483 | |
| 484 | # define SHN_UNDEF Elf_eshn_undefined |
| 485 | # define SHN_ABS Elf_eshn_absolute |
| 486 | # define SHN_COMMON Elf_eshn_common |
| 487 | # endif /* !PT_LOAD */ |
| 488 | |
| 489 | # ifdef __alpha__ |
| 490 | # include <sys/exec_ecoff.h> |
| 491 | # define HDRR struct ecoff_symhdr |
| 492 | # define pHDRR HDRR * |
| 493 | # endif /* __alpha__ */ |
| 494 | |
| 495 | #ifdef __mips__ /* was in pkgsrc patches for 20.7 */ |
| 496 | # define SHT_MIPS_DEBUG DT_MIPS_FLAGS |
| 497 | # define HDRR struct Elf_Shdr |
| 498 | #endif /* __mips__ */ |
| 499 | #endif /* __NetBSD__ */ |
| 500 | |
| 501 | #ifdef __OpenBSD__ |
| 502 | # include <sys/exec_elf.h> |
| 503 | #endif |
| 504 | |
| 505 | #if __GNU_LIBRARY__ - 0 >= 6 |
| 506 | # include <link.h> /* get ElfW etc */ |
| 507 | #endif |
| 508 | |
| 509 | #ifndef ElfW |
| 510 | # define ElfBitsW(bits, type) Elf##bits##_##type |
| 511 | # ifndef ELFSIZE |
| 512 | # ifdef _LP64 |
| 513 | # define ELFSIZE 64 |
| 514 | # else |
| 515 | # define ELFSIZE 32 |
| 516 | # endif |
| 517 | # endif |
| 518 | /* This macro expands `bits' before invoking ElfBitsW. */ |
| 519 | # define ElfExpandBitsW(bits, type) ElfBitsW (bits, type) |
| 520 | # define ElfW(type) ElfExpandBitsW (ELFSIZE, type) |
| 521 | #endif |
| 522 | |
| 523 | /* The code often converts ElfW (Half) values like e_shentsize to ptrdiff_t; |
| 524 | check that this doesn't lose information. */ |
| 525 | #include <intprops.h> |
| 526 | #include <verify.h> |
| 527 | verify ((! TYPE_SIGNED (ElfW (Half)) |
| 528 | || PTRDIFF_MIN <= TYPE_MINIMUM (ElfW (Half))) |
| 529 | && TYPE_MAXIMUM (ElfW (Half)) <= PTRDIFF_MAX); |
| 530 | |
| 531 | #ifdef UNEXELF_DEBUG |
| 532 | # define DEBUG_LOG(expr) fprintf (stderr, #expr " 0x%jx\n", (uintmax_t) (expr)) |
| 533 | #endif |
| 534 | |
| 535 | /* Get the address of a particular section or program header entry, |
| 536 | * accounting for the size of the entries. |
| 537 | */ |
| 538 | /* |
| 539 | On PPC Reference Platform running Solaris 2.5.1 |
| 540 | the plt section is also of type NOBI like the bss section. |
| 541 | (not really stored) and therefore sections after the bss |
| 542 | section start at the plt offset. The plt section is always |
| 543 | the one just before the bss section. |
| 544 | Thus, we modify the test from |
| 545 | if (NEW_SECTION_H (nn).sh_offset >= new_data2_offset) |
| 546 | to |
| 547 | if (NEW_SECTION_H (nn).sh_offset >= |
| 548 | OLD_SECTION_H (old_bss_index-1).sh_offset) |
| 549 | This is just a hack. We should put the new data section |
| 550 | before the .plt section. |
| 551 | And we should not have this routine at all but use |
| 552 | the libelf library to read the old file and create the new |
| 553 | file. |
| 554 | The changed code is minimal and depends on prep set in m/prep.h |
| 555 | Erik Deumens |
| 556 | Quantum Theory Project |
| 557 | University of Florida |
| 558 | deumens@qtp.ufl.edu |
| 559 | Apr 23, 1996 |
| 560 | */ |
| 561 | |
| 562 | static void * |
| 563 | entry_address (void *section_h, ptrdiff_t idx, ptrdiff_t entsize) |
| 564 | { |
| 565 | char *h = section_h; |
| 566 | return h + idx * entsize; |
| 567 | } |
| 568 | |
| 569 | #define OLD_SECTION_H(n) \ |
| 570 | (*(ElfW (Shdr) *) entry_address (old_section_h, n, old_file_h->e_shentsize)) |
| 571 | #define NEW_SECTION_H(n) \ |
| 572 | (*(ElfW (Shdr) *) entry_address (new_section_h, n, new_file_h->e_shentsize)) |
| 573 | #define NEW_PROGRAM_H(n) \ |
| 574 | (*(ElfW (Phdr) *) entry_address (new_program_h, n, new_file_h->e_phentsize)) |
| 575 | |
| 576 | #define PATCH_INDEX(n) ((n) += old_bss_index <= (n)) |
| 577 | typedef unsigned char byte; |
| 578 | |
| 579 | /* Round X up to a multiple of Y. */ |
| 580 | |
| 581 | static ElfW (Addr) |
| 582 | round_up (ElfW (Addr) x, ElfW (Addr) y) |
| 583 | { |
| 584 | ElfW (Addr) rem = x % y; |
| 585 | if (rem == 0) |
| 586 | return x; |
| 587 | return x - rem + y; |
| 588 | } |
| 589 | |
| 590 | /* Return the index of the section named NAME. |
| 591 | SECTION_NAMES, FILE_NAME and FILE_H give information |
| 592 | about the file we are looking in. |
| 593 | |
| 594 | If we don't find the section NAME, that is a fatal error |
| 595 | if NOERROR is false; return -1 if NOERROR is true. */ |
| 596 | |
| 597 | static ptrdiff_t |
| 598 | find_section (const char *name, const char *section_names, const char *file_name, |
| 599 | ElfW (Ehdr) *old_file_h, ElfW (Shdr) *old_section_h, |
| 600 | bool noerror) |
| 601 | { |
| 602 | ptrdiff_t idx; |
| 603 | |
| 604 | for (idx = 1; idx < old_file_h->e_shnum; idx++) |
| 605 | { |
| 606 | char const *found_name = section_names + OLD_SECTION_H (idx).sh_name; |
| 607 | #ifdef UNEXELF_DEBUG |
| 608 | fprintf (stderr, "Looking for %s - found %s\n", name, found_name); |
| 609 | #endif |
| 610 | if (strcmp (name, found_name) == 0) |
| 611 | return idx; |
| 612 | } |
| 613 | |
| 614 | if (! noerror) |
| 615 | fatal ("Can't find %s in %s", name, file_name); |
| 616 | return -1; |
| 617 | } |
| 618 | |
| 619 | /* **************************************************************** |
| 620 | * unexec |
| 621 | * |
| 622 | * driving logic. |
| 623 | * |
| 624 | * In ELF, this works by replacing the old .bss section with a new |
| 625 | * .data section, and inserting an empty .bss immediately afterwards. |
| 626 | * |
| 627 | */ |
| 628 | void |
| 629 | unexec (const char *new_name, const char *old_name) |
| 630 | { |
| 631 | int new_file, old_file; |
| 632 | off_t new_file_size; |
| 633 | void *new_break; |
| 634 | |
| 635 | /* Pointers to the base of the image of the two files. */ |
| 636 | caddr_t old_base, new_base; |
| 637 | |
| 638 | #if MAP_ANON == 0 |
| 639 | int mmap_fd; |
| 640 | #else |
| 641 | # define mmap_fd -1 |
| 642 | #endif |
| 643 | |
| 644 | /* Pointers to the file, program and section headers for the old and |
| 645 | new files. */ |
| 646 | ElfW (Ehdr) *old_file_h, *new_file_h; |
| 647 | ElfW (Phdr) *old_program_h, *new_program_h; |
| 648 | ElfW (Shdr) *old_section_h, *new_section_h; |
| 649 | |
| 650 | /* Point to the section name table in the old file. */ |
| 651 | char *old_section_names; |
| 652 | |
| 653 | ElfW (Addr) old_bss_addr, new_bss_addr; |
| 654 | ElfW (Word) old_bss_size, new_data2_size; |
| 655 | ElfW (Off) new_data2_offset; |
| 656 | ElfW (Addr) new_data2_addr; |
| 657 | ElfW (Off) old_bss_offset; |
| 658 | ElfW (Word) new_data2_incr; |
| 659 | |
| 660 | ptrdiff_t n, nn; |
| 661 | ptrdiff_t old_bss_index, old_sbss_index, old_plt_index; |
| 662 | ptrdiff_t old_data_index, new_data2_index; |
| 663 | #if defined _SYSTYPE_SYSV || defined __sgi |
| 664 | ptrdiff_t old_mdebug_index; |
| 665 | #endif |
| 666 | struct stat stat_buf; |
| 667 | off_t old_file_size; |
| 668 | int mask; |
| 669 | |
| 670 | /* Open the old file, allocate a buffer of the right size, and read |
| 671 | in the file contents. */ |
| 672 | |
| 673 | old_file = emacs_open (old_name, O_RDONLY, 0); |
| 674 | |
| 675 | if (old_file < 0) |
| 676 | fatal ("Can't open %s for reading: %s", old_name, strerror (errno)); |
| 677 | |
| 678 | if (fstat (old_file, &stat_buf) != 0) |
| 679 | fatal ("Can't fstat (%s): %s", old_name, strerror (errno)); |
| 680 | |
| 681 | #if MAP_ANON == 0 |
| 682 | mmap_fd = emacs_open ("/dev/zero", O_RDONLY, 0); |
| 683 | if (mmap_fd < 0) |
| 684 | fatal ("Can't open /dev/zero for reading: %s", strerror (errno)); |
| 685 | #endif |
| 686 | |
| 687 | /* We cannot use malloc here because that may use sbrk. If it does, |
| 688 | we'd dump our temporary buffers with Emacs, and we'd have to be |
| 689 | extra careful to use the correct value of sbrk(0) after |
| 690 | allocating all buffers in the code below, which we aren't. */ |
| 691 | old_file_size = stat_buf.st_size; |
| 692 | if (! (0 <= old_file_size && old_file_size <= SIZE_MAX)) |
| 693 | fatal ("File size out of range"); |
| 694 | old_base = mmap (NULL, old_file_size, PROT_READ | PROT_WRITE, |
| 695 | MAP_ANON | MAP_PRIVATE, mmap_fd, 0); |
| 696 | if (old_base == MAP_FAILED) |
| 697 | fatal ("Can't allocate buffer for %s: %s", old_name, strerror (errno)); |
| 698 | |
| 699 | if (read (old_file, old_base, old_file_size) != old_file_size) |
| 700 | fatal ("Didn't read all of %s: %s", old_name, strerror (errno)); |
| 701 | |
| 702 | /* Get pointers to headers & section names */ |
| 703 | |
| 704 | old_file_h = (ElfW (Ehdr) *) old_base; |
| 705 | old_program_h = (ElfW (Phdr) *) ((byte *) old_base + old_file_h->e_phoff); |
| 706 | old_section_h = (ElfW (Shdr) *) ((byte *) old_base + old_file_h->e_shoff); |
| 707 | old_section_names = (char *) old_base |
| 708 | + OLD_SECTION_H (old_file_h->e_shstrndx).sh_offset; |
| 709 | |
| 710 | /* Find the mdebug section, if any. */ |
| 711 | |
| 712 | #if defined _SYSTYPE_SYSV || defined __sgi |
| 713 | old_mdebug_index = find_section (".mdebug", old_section_names, |
| 714 | old_name, old_file_h, old_section_h, 1); |
| 715 | #endif |
| 716 | |
| 717 | /* Find the old .bss section. Figure out parameters of the new |
| 718 | data2 and bss sections. */ |
| 719 | |
| 720 | old_bss_index = find_section (".bss", old_section_names, |
| 721 | old_name, old_file_h, old_section_h, 0); |
| 722 | |
| 723 | old_sbss_index = find_section (".sbss", old_section_names, |
| 724 | old_name, old_file_h, old_section_h, 1); |
| 725 | if (old_sbss_index != -1) |
| 726 | if (OLD_SECTION_H (old_sbss_index).sh_type != SHT_NOBITS) |
| 727 | old_sbss_index = -1; |
| 728 | |
| 729 | /* PowerPC64 has .plt in the BSS section. */ |
| 730 | old_plt_index = find_section (".plt", old_section_names, |
| 731 | old_name, old_file_h, old_section_h, 1); |
| 732 | if (old_plt_index != -1) |
| 733 | if (OLD_SECTION_H (old_plt_index).sh_type != SHT_NOBITS) |
| 734 | old_plt_index = -1; |
| 735 | |
| 736 | if (old_sbss_index == -1 && old_plt_index == -1) |
| 737 | { |
| 738 | old_bss_addr = OLD_SECTION_H (old_bss_index).sh_addr; |
| 739 | old_bss_size = OLD_SECTION_H (old_bss_index).sh_size; |
| 740 | old_bss_offset = OLD_SECTION_H (old_bss_index).sh_offset; |
| 741 | new_data2_index = old_bss_index; |
| 742 | } |
| 743 | else if (old_plt_index != -1 |
| 744 | && (old_sbss_index == -1 |
| 745 | || (OLD_SECTION_H (old_sbss_index).sh_addr |
| 746 | > OLD_SECTION_H (old_plt_index).sh_addr))) |
| 747 | { |
| 748 | old_bss_addr = OLD_SECTION_H (old_plt_index).sh_addr; |
| 749 | old_bss_size = OLD_SECTION_H (old_bss_index).sh_size |
| 750 | + OLD_SECTION_H (old_plt_index).sh_size; |
| 751 | if (old_sbss_index != -1) |
| 752 | old_bss_size += OLD_SECTION_H (old_sbss_index).sh_size; |
| 753 | old_bss_offset = OLD_SECTION_H (old_plt_index).sh_offset; |
| 754 | new_data2_index = old_plt_index; |
| 755 | } |
| 756 | else |
| 757 | { |
| 758 | old_bss_addr = OLD_SECTION_H (old_sbss_index).sh_addr; |
| 759 | old_bss_size = OLD_SECTION_H (old_bss_index).sh_size |
| 760 | + OLD_SECTION_H (old_sbss_index).sh_size; |
| 761 | old_bss_offset = OLD_SECTION_H (old_sbss_index).sh_offset; |
| 762 | new_data2_index = old_sbss_index; |
| 763 | } |
| 764 | |
| 765 | /* Find the old .data section. Figure out parameters of |
| 766 | the new data2 and bss sections. */ |
| 767 | |
| 768 | old_data_index = find_section (".data", old_section_names, |
| 769 | old_name, old_file_h, old_section_h, 0); |
| 770 | |
| 771 | new_break = sbrk (0); |
| 772 | new_bss_addr = (ElfW (Addr)) new_break; |
| 773 | new_data2_addr = old_bss_addr; |
| 774 | new_data2_size = new_bss_addr - old_bss_addr; |
| 775 | new_data2_offset = OLD_SECTION_H (old_data_index).sh_offset |
| 776 | + (new_data2_addr - OLD_SECTION_H (old_data_index).sh_addr); |
| 777 | /* This is the amount by which the sections following the bss sections |
| 778 | must be shifted in the image. It can differ from new_data2_size if |
| 779 | the end of the old .data section (and thus the offset of the .bss |
| 780 | section) was unaligned. */ |
| 781 | new_data2_incr = new_data2_size + (new_data2_offset - old_bss_offset); |
| 782 | |
| 783 | #ifdef UNEXELF_DEBUG |
| 784 | fprintf (stderr, "old_bss_index %td\n", old_bss_index); |
| 785 | DEBUG_LOG (old_bss_addr); |
| 786 | DEBUG_LOG (old_bss_size); |
| 787 | DEBUG_LOG (old_bss_offset); |
| 788 | DEBUG_LOG (new_bss_addr); |
| 789 | DEBUG_LOG (new_data2_addr); |
| 790 | DEBUG_LOG (new_data2_size); |
| 791 | DEBUG_LOG (new_data2_offset); |
| 792 | DEBUG_LOG (new_data2_incr); |
| 793 | #endif |
| 794 | |
| 795 | if (new_bss_addr < old_bss_addr + old_bss_size) |
| 796 | fatal (".bss shrank when undumping"); |
| 797 | |
| 798 | /* Set the output file to the right size. Allocate a buffer to hold |
| 799 | the image of the new file. Set pointers to various interesting |
| 800 | objects. */ |
| 801 | |
| 802 | new_file = emacs_open (new_name, O_RDWR | O_CREAT, 0666); |
| 803 | if (new_file < 0) |
| 804 | fatal ("Can't creat (%s): %s", new_name, strerror (errno)); |
| 805 | |
| 806 | new_file_size = old_file_size + old_file_h->e_shentsize + new_data2_incr; |
| 807 | |
| 808 | if (ftruncate (new_file, new_file_size)) |
| 809 | fatal ("Can't ftruncate (%s): %s", new_name, strerror (errno)); |
| 810 | |
| 811 | new_base = mmap (NULL, new_file_size, PROT_READ | PROT_WRITE, |
| 812 | MAP_ANON | MAP_PRIVATE, mmap_fd, 0); |
| 813 | if (new_base == MAP_FAILED) |
| 814 | fatal ("Can't allocate buffer for %s: %s", old_name, strerror (errno)); |
| 815 | |
| 816 | new_file_h = (ElfW (Ehdr) *) new_base; |
| 817 | new_program_h = (ElfW (Phdr) *) ((byte *) new_base + old_file_h->e_phoff); |
| 818 | new_section_h = (ElfW (Shdr) *) |
| 819 | ((byte *) new_base + old_file_h->e_shoff + new_data2_incr); |
| 820 | |
| 821 | /* Make our new file, program and section headers as copies of the |
| 822 | originals. */ |
| 823 | |
| 824 | memcpy (new_file_h, old_file_h, old_file_h->e_ehsize); |
| 825 | memcpy (new_program_h, old_program_h, |
| 826 | old_file_h->e_phnum * old_file_h->e_phentsize); |
| 827 | |
| 828 | /* Modify the e_shstrndx if necessary. */ |
| 829 | PATCH_INDEX (new_file_h->e_shstrndx); |
| 830 | |
| 831 | /* Fix up file header. We'll add one section. Section header is |
| 832 | further away now. */ |
| 833 | |
| 834 | new_file_h->e_shoff += new_data2_incr; |
| 835 | new_file_h->e_shnum += 1; |
| 836 | |
| 837 | #ifdef UNEXELF_DEBUG |
| 838 | DEBUG_LOG (old_file_h->e_shoff); |
| 839 | fprintf (stderr, "Old section count %td\n", (ptrdiff_t) old_file_h->e_shnum); |
| 840 | DEBUG_LOG (new_file_h->e_shoff); |
| 841 | fprintf (stderr, "New section count %td\n", (ptrdiff_t) new_file_h->e_shnum); |
| 842 | #endif |
| 843 | |
| 844 | /* Fix up a new program header. Extend the writable data segment so |
| 845 | that the bss area is covered too. Find that segment by looking |
| 846 | for a segment that ends just before the .bss area. Make sure |
| 847 | that no segments are above the new .data2. Put a loop at the end |
| 848 | to adjust the offset and address of any segment that is above |
| 849 | data2, just in case we decide to allow this later. */ |
| 850 | |
| 851 | for (n = new_file_h->e_phnum; --n >= 0; ) |
| 852 | { |
| 853 | /* Compute maximum of all requirements for alignment of section. */ |
| 854 | ElfW (Word) alignment = (NEW_PROGRAM_H (n)).p_align; |
| 855 | if ((OLD_SECTION_H (old_bss_index)).sh_addralign > alignment) |
| 856 | alignment = OLD_SECTION_H (old_bss_index).sh_addralign; |
| 857 | |
| 858 | #ifdef __sgi |
| 859 | /* According to r02kar@x4u2.desy.de (Karsten Kuenne) |
| 860 | and oliva@gnu.org (Alexandre Oliva), on IRIX 5.2, we |
| 861 | always get "Program segment above .bss" when dumping |
| 862 | when the executable doesn't have an sbss section. */ |
| 863 | if (old_sbss_index != -1) |
| 864 | #endif /* __sgi */ |
| 865 | if (NEW_PROGRAM_H (n).p_vaddr + NEW_PROGRAM_H (n).p_filesz |
| 866 | > (old_sbss_index == -1 |
| 867 | ? old_bss_addr |
| 868 | : round_up (old_bss_addr, alignment))) |
| 869 | fatal ("Program segment above .bss in %s", old_name); |
| 870 | |
| 871 | if (NEW_PROGRAM_H (n).p_type == PT_LOAD |
| 872 | && (round_up ((NEW_PROGRAM_H (n)).p_vaddr |
| 873 | + (NEW_PROGRAM_H (n)).p_filesz, |
| 874 | alignment) |
| 875 | == round_up (old_bss_addr, alignment))) |
| 876 | break; |
| 877 | } |
| 878 | if (n < 0) |
| 879 | fatal ("Couldn't find segment next to .bss in %s", old_name); |
| 880 | |
| 881 | /* Make sure that the size includes any padding before the old .bss |
| 882 | section. */ |
| 883 | NEW_PROGRAM_H (n).p_filesz = new_bss_addr - NEW_PROGRAM_H (n).p_vaddr; |
| 884 | NEW_PROGRAM_H (n).p_memsz = NEW_PROGRAM_H (n).p_filesz; |
| 885 | |
| 886 | #if 0 /* Maybe allow section after data2 - does this ever happen? */ |
| 887 | for (n = new_file_h->e_phnum; --n >= 0; ) |
| 888 | { |
| 889 | if (NEW_PROGRAM_H (n).p_vaddr |
| 890 | && NEW_PROGRAM_H (n).p_vaddr >= new_data2_addr) |
| 891 | NEW_PROGRAM_H (n).p_vaddr += new_data2_size - old_bss_size; |
| 892 | |
| 893 | if (NEW_PROGRAM_H (n).p_offset >= new_data2_offset) |
| 894 | NEW_PROGRAM_H (n).p_offset += new_data2_incr; |
| 895 | } |
| 896 | #endif |
| 897 | |
| 898 | /* Fix up section headers based on new .data2 section. Any section |
| 899 | whose offset or virtual address is after the new .data2 section |
| 900 | gets its value adjusted. .bss size becomes zero and new address |
| 901 | is set. data2 section header gets added by copying the existing |
| 902 | .data header and modifying the offset, address and size. */ |
| 903 | |
| 904 | /* Walk through all section headers, insert the new data2 section right |
| 905 | before the new bss section. */ |
| 906 | for (n = 1, nn = 1; n < old_file_h->e_shnum; n++, nn++) |
| 907 | { |
| 908 | caddr_t src; |
| 909 | /* If it is (s)bss section, insert the new data2 section before it. */ |
| 910 | /* new_data2_index is the index of either old_sbss or old_bss, that was |
| 911 | chosen as a section for new_data2. */ |
| 912 | if (n == new_data2_index) |
| 913 | { |
| 914 | /* Steal the data section header for this data2 section. */ |
| 915 | memcpy (&NEW_SECTION_H (nn), &OLD_SECTION_H (old_data_index), |
| 916 | new_file_h->e_shentsize); |
| 917 | |
| 918 | NEW_SECTION_H (nn).sh_addr = new_data2_addr; |
| 919 | NEW_SECTION_H (nn).sh_offset = new_data2_offset; |
| 920 | NEW_SECTION_H (nn).sh_size = new_data2_size; |
| 921 | /* Use the bss section's alignment. This will assure that the |
| 922 | new data2 section always be placed in the same spot as the old |
| 923 | bss section by any other application. */ |
| 924 | NEW_SECTION_H (nn).sh_addralign = OLD_SECTION_H (n).sh_addralign; |
| 925 | |
| 926 | /* Now copy over what we have in the memory now. */ |
| 927 | memcpy (NEW_SECTION_H (nn).sh_offset + new_base, |
| 928 | (caddr_t) OLD_SECTION_H (n).sh_addr, |
| 929 | new_data2_size); |
| 930 | nn++; |
| 931 | } |
| 932 | |
| 933 | memcpy (&NEW_SECTION_H (nn), &OLD_SECTION_H (n), |
| 934 | old_file_h->e_shentsize); |
| 935 | |
| 936 | if (n == old_bss_index |
| 937 | /* The new bss and sbss section's size is zero, and its file offset |
| 938 | and virtual address should be off by NEW_DATA2_SIZE. */ |
| 939 | || n == old_sbss_index || n == old_plt_index |
| 940 | ) |
| 941 | { |
| 942 | /* NN should be `old_s?bss_index + 1' at this point. */ |
| 943 | NEW_SECTION_H (nn).sh_offset = new_data2_offset + new_data2_size; |
| 944 | NEW_SECTION_H (nn).sh_addr = new_data2_addr + new_data2_size; |
| 945 | /* Let the new bss section address alignment be the same as the |
| 946 | section address alignment followed the old bss section, so |
| 947 | this section will be placed in exactly the same place. */ |
| 948 | NEW_SECTION_H (nn).sh_addralign = OLD_SECTION_H (nn).sh_addralign; |
| 949 | NEW_SECTION_H (nn).sh_size = 0; |
| 950 | } |
| 951 | else |
| 952 | { |
| 953 | /* Any section that was originally placed after the .bss |
| 954 | section should now be off by NEW_DATA2_INCR. If a |
| 955 | section overlaps the .bss section, consider it to be |
| 956 | placed after the .bss section. Overlap can occur if the |
| 957 | section just before .bss has less-strict alignment; this |
| 958 | was observed between .symtab and .bss on Solaris 2.5.1 |
| 959 | (sparc) with GCC snapshot 960602. |
| 960 | |
| 961 | > dump -h temacs |
| 962 | |
| 963 | temacs: |
| 964 | |
| 965 | **** SECTION HEADER TABLE **** |
| 966 | [No] Type Flags Addr Offset Size Name |
| 967 | Link Info Adralgn Entsize |
| 968 | |
| 969 | [22] 1 3 0x335150 0x315150 0x4 .data.rel.local |
| 970 | 0 0 0x4 0 |
| 971 | |
| 972 | [23] 8 3 0x335158 0x315158 0x42720 .bss |
| 973 | 0 0 0x8 0 |
| 974 | |
| 975 | [24] 2 0 0 0x315154 0x1c9d0 .symtab |
| 976 | 25 1709 0x4 0x10 |
| 977 | */ |
| 978 | |
| 979 | if (NEW_SECTION_H (nn).sh_offset >= old_bss_offset |
| 980 | || (NEW_SECTION_H (nn).sh_offset + NEW_SECTION_H (nn).sh_size |
| 981 | > new_data2_offset)) |
| 982 | NEW_SECTION_H (nn).sh_offset += new_data2_incr; |
| 983 | |
| 984 | /* Any section that was originally placed after the section |
| 985 | header table should now be off by the size of one section |
| 986 | header table entry. */ |
| 987 | if (NEW_SECTION_H (nn).sh_offset > new_file_h->e_shoff) |
| 988 | NEW_SECTION_H (nn).sh_offset += new_file_h->e_shentsize; |
| 989 | } |
| 990 | |
| 991 | /* If any section hdr refers to the section after the new .data |
| 992 | section, make it refer to next one because we have inserted |
| 993 | a new section in between. */ |
| 994 | |
| 995 | PATCH_INDEX (NEW_SECTION_H (nn).sh_link); |
| 996 | /* For symbol tables, info is a symbol table index, |
| 997 | so don't change it. */ |
| 998 | if (NEW_SECTION_H (nn).sh_type != SHT_SYMTAB |
| 999 | && NEW_SECTION_H (nn).sh_type != SHT_DYNSYM) |
| 1000 | PATCH_INDEX (NEW_SECTION_H (nn).sh_info); |
| 1001 | |
| 1002 | if (old_sbss_index != -1) |
| 1003 | if (!strcmp (old_section_names + NEW_SECTION_H (nn).sh_name, ".sbss")) |
| 1004 | { |
| 1005 | NEW_SECTION_H (nn).sh_offset = |
| 1006 | round_up (NEW_SECTION_H (nn).sh_offset, |
| 1007 | NEW_SECTION_H (nn).sh_addralign); |
| 1008 | NEW_SECTION_H (nn).sh_type = SHT_PROGBITS; |
| 1009 | } |
| 1010 | |
| 1011 | /* Now, start to copy the content of sections. */ |
| 1012 | if (NEW_SECTION_H (nn).sh_type == SHT_NULL |
| 1013 | || NEW_SECTION_H (nn).sh_type == SHT_NOBITS) |
| 1014 | continue; |
| 1015 | |
| 1016 | /* Write out the sections. .data and .data1 (and data2, called |
| 1017 | ".data" in the strings table) get copied from the current process |
| 1018 | instead of the old file. */ |
| 1019 | if (!strcmp (old_section_names + NEW_SECTION_H (n).sh_name, ".data") |
| 1020 | || !strcmp ((old_section_names + NEW_SECTION_H (n).sh_name), |
| 1021 | ".sdata") |
| 1022 | || !strcmp ((old_section_names + NEW_SECTION_H (n).sh_name), |
| 1023 | ".lit4") |
| 1024 | || !strcmp ((old_section_names + NEW_SECTION_H (n).sh_name), |
| 1025 | ".lit8") |
| 1026 | /* The conditional bit below was in Oliva's original code |
| 1027 | (1999-08-25) and seems to have been dropped by mistake |
| 1028 | subsequently. It prevents a crash at startup under X in |
| 1029 | `IRIX64 6.5 6.5.17m', whether compiled on that release or |
| 1030 | an earlier one. It causes no trouble on the other ELF |
| 1031 | platforms I could test (Irix 6.5.15m, Solaris 8, Debian |
| 1032 | Potato x86, Debian Woody SPARC); however, it's reported |
| 1033 | to cause crashes under some version of GNU/Linux. It's |
| 1034 | not yet clear what's changed in that Irix version to |
| 1035 | cause the problem, or why the fix sometimes fails under |
| 1036 | GNU/Linux. There's probably no good reason to have |
| 1037 | something Irix-specific here, but this will have to do |
| 1038 | for now. IRIX6_5 is the most specific macro we have to |
| 1039 | test. -- fx 2002-10-01 |
| 1040 | |
| 1041 | The issue _looks_ as though it's gone away on 6.5.18m, |
| 1042 | but maybe it's still lurking, to be triggered by some |
| 1043 | change in the binary. It appears to concern the dynamic |
| 1044 | loader, but I never got anywhere with an SGI support call |
| 1045 | seeking clues. -- fx 2002-11-29. */ |
| 1046 | #ifdef IRIX6_5 |
| 1047 | || !strcmp ((old_section_names + NEW_SECTION_H (n).sh_name), |
| 1048 | ".got") |
| 1049 | #endif |
| 1050 | || !strcmp ((old_section_names + NEW_SECTION_H (n).sh_name), |
| 1051 | ".sdata1") |
| 1052 | || !strcmp ((old_section_names + NEW_SECTION_H (n).sh_name), |
| 1053 | ".data1") |
| 1054 | || !strcmp ((old_section_names + NEW_SECTION_H (n).sh_name), |
| 1055 | ".sbss")) |
| 1056 | src = (caddr_t) OLD_SECTION_H (n).sh_addr; |
| 1057 | else |
| 1058 | src = old_base + OLD_SECTION_H (n).sh_offset; |
| 1059 | |
| 1060 | memcpy (NEW_SECTION_H (nn).sh_offset + new_base, src, |
| 1061 | NEW_SECTION_H (nn).sh_size); |
| 1062 | |
| 1063 | #if defined __alpha__ && !defined __OpenBSD__ |
| 1064 | /* Update Alpha COFF symbol table: */ |
| 1065 | if (strcmp (old_section_names + OLD_SECTION_H (n).sh_name, ".mdebug") |
| 1066 | == 0) |
| 1067 | { |
| 1068 | pHDRR symhdr = (pHDRR) (NEW_SECTION_H (nn).sh_offset + new_base); |
| 1069 | |
| 1070 | symhdr->cbLineOffset += new_data2_size; |
| 1071 | symhdr->cbDnOffset += new_data2_size; |
| 1072 | symhdr->cbPdOffset += new_data2_size; |
| 1073 | symhdr->cbSymOffset += new_data2_size; |
| 1074 | symhdr->cbOptOffset += new_data2_size; |
| 1075 | symhdr->cbAuxOffset += new_data2_size; |
| 1076 | symhdr->cbSsOffset += new_data2_size; |
| 1077 | symhdr->cbSsExtOffset += new_data2_size; |
| 1078 | symhdr->cbFdOffset += new_data2_size; |
| 1079 | symhdr->cbRfdOffset += new_data2_size; |
| 1080 | symhdr->cbExtOffset += new_data2_size; |
| 1081 | } |
| 1082 | #endif /* __alpha__ && !__OpenBSD__ */ |
| 1083 | |
| 1084 | #if defined (_SYSTYPE_SYSV) |
| 1085 | if (NEW_SECTION_H (nn).sh_type == SHT_MIPS_DEBUG |
| 1086 | && old_mdebug_index != -1) |
| 1087 | { |
| 1088 | ptrdiff_t new_offset = NEW_SECTION_H (nn).sh_offset; |
| 1089 | ptrdiff_t old_offset = OLD_SECTION_H (old_mdebug_index).sh_offset; |
| 1090 | ptrdiff_t diff = new_offset - old_offset; |
| 1091 | HDRR *phdr = (HDRR *)(NEW_SECTION_H (nn).sh_offset + new_base); |
| 1092 | |
| 1093 | if (diff) |
| 1094 | { |
| 1095 | phdr->cbLineOffset += diff; |
| 1096 | phdr->cbDnOffset += diff; |
| 1097 | phdr->cbPdOffset += diff; |
| 1098 | phdr->cbSymOffset += diff; |
| 1099 | phdr->cbOptOffset += diff; |
| 1100 | phdr->cbAuxOffset += diff; |
| 1101 | phdr->cbSsOffset += diff; |
| 1102 | phdr->cbSsExtOffset += diff; |
| 1103 | phdr->cbFdOffset += diff; |
| 1104 | phdr->cbRfdOffset += diff; |
| 1105 | phdr->cbExtOffset += diff; |
| 1106 | } |
| 1107 | } |
| 1108 | #endif /* _SYSTYPE_SYSV */ |
| 1109 | |
| 1110 | #if __sgi |
| 1111 | /* Adjust the HDRR offsets in .mdebug and copy the |
| 1112 | line data if it's in its usual 'hole' in the object. |
| 1113 | Makes the new file debuggable with dbx. |
| 1114 | patches up two problems: the absolute file offsets |
| 1115 | in the HDRR record of .mdebug (see /usr/include/syms.h), and |
| 1116 | the ld bug that gets the line table in a hole in the |
| 1117 | elf file rather than in the .mdebug section proper. |
| 1118 | David Anderson. davea@sgi.com Jan 16,1994. */ |
| 1119 | if (n == old_mdebug_index) |
| 1120 | { |
| 1121 | #define MDEBUGADJUST(__ct,__fileaddr) \ |
| 1122 | if (n_phdrr->__ct > 0) \ |
| 1123 | { \ |
| 1124 | n_phdrr->__fileaddr += movement; \ |
| 1125 | } |
| 1126 | |
| 1127 | HDRR * o_phdrr = (HDRR *)((byte *)old_base + OLD_SECTION_H (n).sh_offset); |
| 1128 | HDRR * n_phdrr = (HDRR *)((byte *)new_base + NEW_SECTION_H (nn).sh_offset); |
| 1129 | unsigned movement = new_data2_size; |
| 1130 | |
| 1131 | MDEBUGADJUST (idnMax, cbDnOffset); |
| 1132 | MDEBUGADJUST (ipdMax, cbPdOffset); |
| 1133 | MDEBUGADJUST (isymMax, cbSymOffset); |
| 1134 | MDEBUGADJUST (ioptMax, cbOptOffset); |
| 1135 | MDEBUGADJUST (iauxMax, cbAuxOffset); |
| 1136 | MDEBUGADJUST (issMax, cbSsOffset); |
| 1137 | MDEBUGADJUST (issExtMax, cbSsExtOffset); |
| 1138 | MDEBUGADJUST (ifdMax, cbFdOffset); |
| 1139 | MDEBUGADJUST (crfd, cbRfdOffset); |
| 1140 | MDEBUGADJUST (iextMax, cbExtOffset); |
| 1141 | /* The Line Section, being possible off in a hole of the object, |
| 1142 | requires special handling. */ |
| 1143 | if (n_phdrr->cbLine > 0) |
| 1144 | { |
| 1145 | if (o_phdrr->cbLineOffset > (OLD_SECTION_H (n).sh_offset |
| 1146 | + OLD_SECTION_H (n).sh_size)) |
| 1147 | { |
| 1148 | /* line data is in a hole in elf. do special copy and adjust |
| 1149 | for this ld mistake. |
| 1150 | */ |
| 1151 | n_phdrr->cbLineOffset += movement; |
| 1152 | |
| 1153 | memcpy (n_phdrr->cbLineOffset + new_base, |
| 1154 | o_phdrr->cbLineOffset + old_base, n_phdrr->cbLine); |
| 1155 | } |
| 1156 | else |
| 1157 | { |
| 1158 | /* somehow line data is in .mdebug as it is supposed to be. */ |
| 1159 | MDEBUGADJUST (cbLine, cbLineOffset); |
| 1160 | } |
| 1161 | } |
| 1162 | } |
| 1163 | #endif /* __sgi */ |
| 1164 | |
| 1165 | /* If it is the symbol table, its st_shndx field needs to be patched. */ |
| 1166 | if (NEW_SECTION_H (nn).sh_type == SHT_SYMTAB |
| 1167 | || NEW_SECTION_H (nn).sh_type == SHT_DYNSYM) |
| 1168 | { |
| 1169 | ElfW (Shdr) *spt = &NEW_SECTION_H (nn); |
| 1170 | ptrdiff_t num = spt->sh_size / spt->sh_entsize; |
| 1171 | ElfW (Sym) * sym = (ElfW (Sym) *) (NEW_SECTION_H (nn).sh_offset + |
| 1172 | new_base); |
| 1173 | for (; num--; sym++) |
| 1174 | { |
| 1175 | if ((sym->st_shndx == SHN_UNDEF) |
| 1176 | || (sym->st_shndx == SHN_ABS) |
| 1177 | || (sym->st_shndx == SHN_COMMON)) |
| 1178 | continue; |
| 1179 | |
| 1180 | PATCH_INDEX (sym->st_shndx); |
| 1181 | } |
| 1182 | } |
| 1183 | } |
| 1184 | |
| 1185 | /* Update the symbol values of _edata and _end. */ |
| 1186 | for (n = new_file_h->e_shnum; 0 < --n; ) |
| 1187 | { |
| 1188 | byte *symnames; |
| 1189 | ElfW (Sym) *symp, *symendp; |
| 1190 | |
| 1191 | if (NEW_SECTION_H (n).sh_type != SHT_DYNSYM |
| 1192 | && NEW_SECTION_H (n).sh_type != SHT_SYMTAB) |
| 1193 | continue; |
| 1194 | |
| 1195 | symnames = ((byte *) new_base |
| 1196 | + NEW_SECTION_H (NEW_SECTION_H (n).sh_link).sh_offset); |
| 1197 | symp = (ElfW (Sym) *) (NEW_SECTION_H (n).sh_offset + new_base); |
| 1198 | symendp = (ElfW (Sym) *) ((byte *)symp + NEW_SECTION_H (n).sh_size); |
| 1199 | |
| 1200 | for (; symp < symendp; symp ++) |
| 1201 | { |
| 1202 | if (strcmp ((char *) (symnames + symp->st_name), "_end") == 0 |
| 1203 | || strcmp ((char *) (symnames + symp->st_name), "end") == 0 |
| 1204 | || strcmp ((char *) (symnames + symp->st_name), "_edata") == 0 |
| 1205 | || strcmp ((char *) (symnames + symp->st_name), "edata") == 0) |
| 1206 | memcpy (&symp->st_value, &new_bss_addr, sizeof (new_bss_addr)); |
| 1207 | |
| 1208 | /* Strictly speaking, #ifdef below is not necessary. But we |
| 1209 | keep it to indicate that this kind of change may also be |
| 1210 | necessary for other unexecs to support GNUstep. */ |
| 1211 | #ifdef NS_IMPL_GNUSTEP |
| 1212 | /* ObjC runtime modifies the values of some data structures |
| 1213 | such as classes and selectors in the .data section after |
| 1214 | loading. As the dump process copies the .data section |
| 1215 | from the current process, that causes problems when the |
| 1216 | modified classes are reinitialized in the dumped |
| 1217 | executable. We copy such data from the old file, not |
| 1218 | from the current process. */ |
| 1219 | if (strncmp ((char *) (symnames + symp->st_name), |
| 1220 | "_OBJC_", sizeof ("_OBJC_") - 1) == 0) |
| 1221 | { |
| 1222 | caddr_t old, new; |
| 1223 | |
| 1224 | new = ((symp->st_value - NEW_SECTION_H (symp->st_shndx).sh_addr) |
| 1225 | + NEW_SECTION_H (symp->st_shndx).sh_offset + new_base); |
| 1226 | /* "Unpatch" index. */ |
| 1227 | nn = symp->st_shndx; |
| 1228 | if (nn > old_bss_index) |
| 1229 | nn--; |
| 1230 | if (nn == old_bss_index) |
| 1231 | memset (new, 0, symp->st_size); |
| 1232 | else |
| 1233 | { |
| 1234 | old = ((symp->st_value |
| 1235 | - NEW_SECTION_H (symp->st_shndx).sh_addr) |
| 1236 | + OLD_SECTION_H (nn).sh_offset + old_base); |
| 1237 | memcpy (new, old, symp->st_size); |
| 1238 | } |
| 1239 | } |
| 1240 | #endif |
| 1241 | } |
| 1242 | } |
| 1243 | |
| 1244 | /* This loop seeks out relocation sections for the data section, so |
| 1245 | that it can undo relocations performed by the runtime linker. */ |
| 1246 | for (n = new_file_h->e_shnum; 0 < --n; ) |
| 1247 | { |
| 1248 | ElfW (Shdr) section = NEW_SECTION_H (n); |
| 1249 | |
| 1250 | /* Cause a compilation error if anyone uses n instead of nn below. */ |
| 1251 | #define n ((void) 0); |
| 1252 | n /* Prevent 'macro "n" is not used' warnings. */ |
| 1253 | |
| 1254 | switch (section.sh_type) |
| 1255 | { |
| 1256 | default: |
| 1257 | break; |
| 1258 | case SHT_REL: |
| 1259 | case SHT_RELA: |
| 1260 | /* This code handles two different size structs, but there should |
| 1261 | be no harm in that provided that r_offset is always the first |
| 1262 | member. */ |
| 1263 | nn = section.sh_info; |
| 1264 | if (!strcmp (old_section_names + NEW_SECTION_H (nn).sh_name, ".data") |
| 1265 | || !strcmp ((old_section_names + NEW_SECTION_H (nn).sh_name), |
| 1266 | ".sdata") |
| 1267 | || !strcmp ((old_section_names + NEW_SECTION_H (nn).sh_name), |
| 1268 | ".lit4") |
| 1269 | || !strcmp ((old_section_names + NEW_SECTION_H (nn).sh_name), |
| 1270 | ".lit8") |
| 1271 | #ifdef IRIX6_5 /* see above */ |
| 1272 | || !strcmp ((old_section_names + NEW_SECTION_H (nn).sh_name), |
| 1273 | ".got") |
| 1274 | #endif |
| 1275 | || !strcmp ((old_section_names + NEW_SECTION_H (nn).sh_name), |
| 1276 | ".sdata1") |
| 1277 | || !strcmp ((old_section_names + NEW_SECTION_H (nn).sh_name), |
| 1278 | ".data1")) |
| 1279 | { |
| 1280 | ElfW (Addr) offset = (NEW_SECTION_H (nn).sh_addr |
| 1281 | - NEW_SECTION_H (nn).sh_offset); |
| 1282 | caddr_t reloc = old_base + section.sh_offset, end; |
| 1283 | for (end = reloc + section.sh_size; reloc < end; |
| 1284 | reloc += section.sh_entsize) |
| 1285 | { |
| 1286 | ElfW (Addr) addr = ((ElfW (Rel) *) reloc)->r_offset - offset; |
| 1287 | #ifdef __alpha__ |
| 1288 | /* The Alpha ELF binutils currently have a bug that |
| 1289 | sometimes results in relocs that contain all |
| 1290 | zeroes. Work around this for now... */ |
| 1291 | if (((ElfW (Rel) *) reloc)->r_offset == 0) |
| 1292 | continue; |
| 1293 | #endif |
| 1294 | memcpy (new_base + addr, old_base + addr, sizeof (ElfW (Addr))); |
| 1295 | } |
| 1296 | } |
| 1297 | break; |
| 1298 | } |
| 1299 | |
| 1300 | #undef n |
| 1301 | } |
| 1302 | |
| 1303 | /* Write out new_file, and free the buffers. */ |
| 1304 | |
| 1305 | if (write (new_file, new_base, new_file_size) != new_file_size) |
| 1306 | fatal ("Didn't write %lu bytes to %s: %s", |
| 1307 | (unsigned long) new_file_size, new_name, strerror (errno)); |
| 1308 | munmap (old_base, old_file_size); |
| 1309 | munmap (new_base, new_file_size); |
| 1310 | |
| 1311 | /* Close the files and make the new file executable. */ |
| 1312 | |
| 1313 | #if MAP_ANON == 0 |
| 1314 | emacs_close (mmap_fd); |
| 1315 | #endif |
| 1316 | |
| 1317 | if (emacs_close (old_file) != 0) |
| 1318 | fatal ("Can't close (%s): %s", old_name, strerror (errno)); |
| 1319 | |
| 1320 | if (emacs_close (new_file) != 0) |
| 1321 | fatal ("Can't close (%s): %s", new_name, strerror (errno)); |
| 1322 | |
| 1323 | if (stat (new_name, &stat_buf) != 0) |
| 1324 | fatal ("Can't stat (%s): %s", new_name, strerror (errno)); |
| 1325 | |
| 1326 | mask = umask (777); |
| 1327 | umask (mask); |
| 1328 | stat_buf.st_mode |= 0111 & ~mask; |
| 1329 | if (chmod (new_name, stat_buf.st_mode) != 0) |
| 1330 | fatal ("Can't chmod (%s): %s", new_name, strerror (errno)); |
| 1331 | } |