| 1 | /* Copyright (C) 1985, 1986, 1987, 1988, 1992, 1993, 1994, 2001, 2002, 2003, |
| 2 | 2004, 2005, 2006, 2007, 2008 Free Software 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 | /* |
| 21 | * unexec.c - Convert a running program into an a.out file. |
| 22 | * |
| 23 | * Author: Spencer W. Thomas |
| 24 | * Computer Science Dept. |
| 25 | * University of Utah |
| 26 | * Date: Tue Mar 2 1982 |
| 27 | * Modified heavily since then. |
| 28 | * |
| 29 | * Synopsis: |
| 30 | * unexec (new_name, a_name, data_start, bss_start, entry_address) |
| 31 | * char *new_name, *a_name; |
| 32 | * unsigned data_start, bss_start, entry_address; |
| 33 | * |
| 34 | * Takes a snapshot of the program and makes an a.out format file in the |
| 35 | * file named by the string argument new_name. |
| 36 | * If a_name is non-NULL, the symbol table will be taken from the given file. |
| 37 | * On some machines, an existing a_name file is required. |
| 38 | * |
| 39 | * The boundaries within the a.out file may be adjusted with the data_start |
| 40 | * and bss_start arguments. Either or both may be given as 0 for defaults. |
| 41 | * |
| 42 | * Data_start gives the boundary between the text segment and the data |
| 43 | * segment of the program. The text segment can contain shared, read-only |
| 44 | * program code and literal data, while the data segment is always unshared |
| 45 | * and unprotected. Data_start gives the lowest unprotected address. |
| 46 | * The value you specify may be rounded down to a suitable boundary |
| 47 | * as required by the machine you are using. |
| 48 | * |
| 49 | * Specifying zero for data_start means the boundary between text and data |
| 50 | * should not be the same as when the program was loaded. |
| 51 | * If NO_REMAP is defined, the argument data_start is ignored and the |
| 52 | * segment boundaries are never changed. |
| 53 | * |
| 54 | * Bss_start indicates how much of the data segment is to be saved in the |
| 55 | * a.out file and restored when the program is executed. It gives the lowest |
| 56 | * unsaved address, and is rounded up to a page boundary. The default when 0 |
| 57 | * is given assumes that the entire data segment is to be stored, including |
| 58 | * the previous data and bss as well as any additional storage allocated with |
| 59 | * break (2). |
| 60 | * |
| 61 | * The new file is set up to start at entry_address. |
| 62 | * |
| 63 | * If you make improvements I'd like to get them too. |
| 64 | * harpo!utah-cs!thomas, thomas@Utah-20 |
| 65 | * |
| 66 | */ |
| 67 | |
| 68 | /* Modified to support SysVr3 shared libraries by James Van Artsdalen |
| 69 | * of Dell Computer Corporation. james@bigtex.cactus.org. |
| 70 | */ |
| 71 | |
| 72 | /* There are several compilation parameters affecting unexec: |
| 73 | |
| 74 | * COFF |
| 75 | |
| 76 | Define this if your system uses COFF for executables. |
| 77 | |
| 78 | * NO_REMAP |
| 79 | |
| 80 | Define this if you do not want to try to save Emacs's pure data areas |
| 81 | as part of the text segment. |
| 82 | |
| 83 | Saving them as text is good because it allows users to share more. |
| 84 | |
| 85 | However, on machines that locate the text area far from the data area, |
| 86 | the boundary cannot feasibly be moved. Such machines require |
| 87 | NO_REMAP. |
| 88 | |
| 89 | Also, remapping can cause trouble with the built-in startup routine |
| 90 | /lib/crt0.o, which defines `environ' as an initialized variable. |
| 91 | Dumping `environ' as pure does not work! So, to use remapping, |
| 92 | you must write a startup routine for your machine in Emacs's crt0.c. |
| 93 | If NO_REMAP is defined, Emacs uses the system's crt0.o. |
| 94 | |
| 95 | * SECTION_ALIGNMENT |
| 96 | |
| 97 | Some machines that use COFF executables require that each section |
| 98 | start on a certain boundary *in the COFF file*. Such machines should |
| 99 | define SECTION_ALIGNMENT to a mask of the low-order bits that must be |
| 100 | zero on such a boundary. This mask is used to control padding between |
| 101 | segments in the COFF file. |
| 102 | |
| 103 | If SECTION_ALIGNMENT is not defined, the segments are written |
| 104 | consecutively with no attempt at alignment. This is right for |
| 105 | unmodified system V. |
| 106 | |
| 107 | * SEGMENT_MASK |
| 108 | |
| 109 | Some machines require that the beginnings and ends of segments |
| 110 | *in core* be on certain boundaries. For most machines, a page |
| 111 | boundary is sufficient. That is the default. When a larger |
| 112 | boundary is needed, define SEGMENT_MASK to a mask of |
| 113 | the bits that must be zero on such a boundary. |
| 114 | |
| 115 | * A_TEXT_OFFSET(HDR) |
| 116 | |
| 117 | Some machines count the a.out header as part of the size of the text |
| 118 | segment (a_text); they may actually load the header into core as the |
| 119 | first data in the text segment. Some have additional padding between |
| 120 | the header and the real text of the program that is counted in a_text. |
| 121 | |
| 122 | For these machines, define A_TEXT_OFFSET(HDR) to examine the header |
| 123 | structure HDR and return the number of bytes to add to `a_text' |
| 124 | before writing it (above and beyond the number of bytes of actual |
| 125 | program text). HDR's standard fields are already correct, except that |
| 126 | this adjustment to the `a_text' field has not yet been made; |
| 127 | thus, the amount of offset can depend on the data in the file. |
| 128 | |
| 129 | * A_TEXT_SEEK(HDR) |
| 130 | |
| 131 | If defined, this macro specifies the number of bytes to seek into the |
| 132 | a.out file before starting to write the text segment. |
| 133 | |
| 134 | * ADJUST_EXEC_HEADER |
| 135 | |
| 136 | This macro can be used to generate statements to adjust or |
| 137 | initialize nonstandard fields in the file header |
| 138 | |
| 139 | * ADDR_CORRECT(ADDR) |
| 140 | |
| 141 | Macro to correct an int which is the bit pattern of a pointer to a byte |
| 142 | into an int which is the number of a byte. |
| 143 | |
| 144 | This macro has a default definition which is usually right. |
| 145 | This default definition is a no-op on most machines (where a |
| 146 | pointer looks like an int) but not on all machines. |
| 147 | |
| 148 | */ |
| 149 | |
| 150 | #ifndef emacs |
| 151 | #define PERROR(arg) perror (arg); return -1 |
| 152 | #else |
| 153 | #include <config.h> |
| 154 | #define PERROR(file) report_error (file, new) |
| 155 | #endif |
| 156 | |
| 157 | #ifndef CANNOT_DUMP /* all rest of file! */ |
| 158 | |
| 159 | #if defined(COFF) && defined(HAVE_COFF_H) |
| 160 | #include <coff.h> |
| 161 | #ifdef MSDOS |
| 162 | #if __DJGPP__ > 1 |
| 163 | #include <fcntl.h> /* for O_RDONLY, O_RDWR */ |
| 164 | #include <crt0.h> /* for _crt0_startup_flags and its bits */ |
| 165 | static int save_djgpp_startup_flags; |
| 166 | #endif /* __DJGPP__ > 1 */ |
| 167 | #define filehdr external_filehdr |
| 168 | #define scnhdr external_scnhdr |
| 169 | #define syment external_syment |
| 170 | #define auxent external_auxent |
| 171 | #define n_numaux e_numaux |
| 172 | #define n_type e_type |
| 173 | struct aouthdr |
| 174 | { |
| 175 | unsigned short magic; /* type of file */ |
| 176 | unsigned short vstamp; /* version stamp */ |
| 177 | unsigned long tsize; /* text size in bytes, padded to FW bdry*/ |
| 178 | unsigned long dsize; /* initialized data " " */ |
| 179 | unsigned long bsize; /* uninitialized data " " */ |
| 180 | unsigned long entry; /* entry pt. */ |
| 181 | unsigned long text_start;/* base of text used for this file */ |
| 182 | unsigned long data_start;/* base of data used for this file */ |
| 183 | }; |
| 184 | #endif /* not MSDOS */ |
| 185 | #else /* not COFF */ |
| 186 | #include <a.out.h> |
| 187 | #endif /* not COFF */ |
| 188 | |
| 189 | /* Define getpagesize if the system does not. |
| 190 | Note that this may depend on symbols defined in a.out.h. */ |
| 191 | #include "getpagesize.h" |
| 192 | |
| 193 | #ifndef makedev /* Try to detect types.h already loaded */ |
| 194 | #include <sys/types.h> |
| 195 | #endif /* makedev */ |
| 196 | #include <stdio.h> |
| 197 | #include <sys/stat.h> |
| 198 | #include <errno.h> |
| 199 | |
| 200 | #include <sys/file.h> /* Must be after sys/types.h for USG*/ |
| 201 | |
| 202 | #ifdef USG5 |
| 203 | #include <fcntl.h> |
| 204 | #endif |
| 205 | |
| 206 | #ifndef O_RDONLY |
| 207 | #define O_RDONLY 0 |
| 208 | #endif |
| 209 | #ifndef O_RDWR |
| 210 | #define O_RDWR 2 |
| 211 | #endif |
| 212 | |
| 213 | |
| 214 | extern char *start_of_text (); /* Start of text */ |
| 215 | extern char *start_of_data (); /* Start of initialized data */ |
| 216 | |
| 217 | #ifdef COFF |
| 218 | static long block_copy_start; /* Old executable start point */ |
| 219 | static struct filehdr f_hdr; /* File header */ |
| 220 | static struct aouthdr f_ohdr; /* Optional file header (a.out) */ |
| 221 | long bias; /* Bias to add for growth */ |
| 222 | long lnnoptr; /* Pointer to line-number info within file */ |
| 223 | #define SYMS_START block_copy_start |
| 224 | |
| 225 | static long text_scnptr; |
| 226 | static long data_scnptr; |
| 227 | |
| 228 | static long coff_offset; |
| 229 | |
| 230 | #else /* not COFF */ |
| 231 | |
| 232 | extern char *sbrk (); |
| 233 | |
| 234 | #define SYMS_START ((long) N_SYMOFF (ohdr)) |
| 235 | |
| 236 | #if defined (USG) |
| 237 | static struct bhdr hdr, ohdr; |
| 238 | #define a_magic fmagic |
| 239 | #define a_text tsize |
| 240 | #define a_data dsize |
| 241 | #define a_bss bsize |
| 242 | #define a_syms ssize |
| 243 | #define a_trsize rtsize |
| 244 | #define a_drsize rdsize |
| 245 | #define a_entry entry |
| 246 | #define N_BADMAG(x) \ |
| 247 | (((x).fmagic)!=OMAGIC && ((x).fmagic)!=NMAGIC &&\ |
| 248 | ((x).fmagic)!=FMAGIC && ((x).fmagic)!=IMAGIC) |
| 249 | #define NEWMAGIC FMAGIC |
| 250 | #else /* not USG */ |
| 251 | static struct exec hdr, ohdr; |
| 252 | #define NEWMAGIC ZMAGIC |
| 253 | #endif /* not USG */ |
| 254 | |
| 255 | static int unexec_text_start; |
| 256 | static int unexec_data_start; |
| 257 | |
| 258 | #endif /* not COFF */ |
| 259 | |
| 260 | static int pagemask; |
| 261 | |
| 262 | /* Correct an int which is the bit pattern of a pointer to a byte |
| 263 | into an int which is the number of a byte. |
| 264 | This is a no-op on ordinary machines, but not on all. */ |
| 265 | |
| 266 | #ifndef ADDR_CORRECT /* Let m-*.h files override this definition */ |
| 267 | #define ADDR_CORRECT(x) ((char *)(x) - (char*)0) |
| 268 | #endif |
| 269 | |
| 270 | #ifdef emacs |
| 271 | |
| 272 | #include "lisp.h" |
| 273 | |
| 274 | static |
| 275 | report_error (file, fd) |
| 276 | char *file; |
| 277 | int fd; |
| 278 | { |
| 279 | if (fd) |
| 280 | close (fd); |
| 281 | report_file_error ("Cannot unexec", Fcons (build_string (file), Qnil)); |
| 282 | } |
| 283 | #endif /* emacs */ |
| 284 | |
| 285 | #define ERROR0(msg) report_error_1 (new, msg, 0, 0); return -1 |
| 286 | #define ERROR1(msg,x) report_error_1 (new, msg, x, 0); return -1 |
| 287 | #define ERROR2(msg,x,y) report_error_1 (new, msg, x, y); return -1 |
| 288 | |
| 289 | static |
| 290 | report_error_1 (fd, msg, a1, a2) |
| 291 | int fd; |
| 292 | char *msg; |
| 293 | int a1, a2; |
| 294 | { |
| 295 | close (fd); |
| 296 | #ifdef emacs |
| 297 | error (msg, a1, a2); |
| 298 | #else |
| 299 | fprintf (stderr, msg, a1, a2); |
| 300 | fprintf (stderr, "\n"); |
| 301 | #endif |
| 302 | } |
| 303 | \f |
| 304 | static int make_hdr (); |
| 305 | static int copy_text_and_data (); |
| 306 | static int copy_sym (); |
| 307 | static void mark_x (); |
| 308 | |
| 309 | /* **************************************************************** |
| 310 | * make_hdr |
| 311 | * |
| 312 | * Make the header in the new a.out from the header in core. |
| 313 | * Modify the text and data sizes. |
| 314 | */ |
| 315 | static int |
| 316 | make_hdr (new, a_out, data_start, bss_start, entry_address, a_name, new_name) |
| 317 | int new, a_out; |
| 318 | unsigned data_start, bss_start, entry_address; |
| 319 | char *a_name; |
| 320 | char *new_name; |
| 321 | { |
| 322 | int tem; |
| 323 | #ifdef COFF |
| 324 | auto struct scnhdr f_thdr; /* Text section header */ |
| 325 | auto struct scnhdr f_dhdr; /* Data section header */ |
| 326 | auto struct scnhdr f_bhdr; /* Bss section header */ |
| 327 | auto struct scnhdr scntemp; /* Temporary section header */ |
| 328 | register int scns; |
| 329 | #endif /* COFF */ |
| 330 | unsigned int bss_end; |
| 331 | |
| 332 | pagemask = getpagesize () - 1; |
| 333 | |
| 334 | /* Adjust text/data boundary. */ |
| 335 | #ifdef NO_REMAP |
| 336 | data_start = (int) start_of_data (); |
| 337 | #else /* not NO_REMAP */ |
| 338 | if (!data_start) |
| 339 | data_start = (int) start_of_data (); |
| 340 | #endif /* not NO_REMAP */ |
| 341 | data_start = ADDR_CORRECT (data_start); |
| 342 | |
| 343 | #ifdef SEGMENT_MASK |
| 344 | data_start = data_start & ~SEGMENT_MASK; /* (Down) to segment boundary. */ |
| 345 | #else |
| 346 | data_start = data_start & ~pagemask; /* (Down) to page boundary. */ |
| 347 | #endif |
| 348 | |
| 349 | bss_end = ADDR_CORRECT (sbrk (0)) + pagemask; |
| 350 | bss_end &= ~ pagemask; |
| 351 | |
| 352 | /* Adjust data/bss boundary. */ |
| 353 | if (bss_start != 0) |
| 354 | { |
| 355 | bss_start = (ADDR_CORRECT (bss_start) + pagemask); |
| 356 | /* (Up) to page bdry. */ |
| 357 | bss_start &= ~ pagemask; |
| 358 | if (bss_start > bss_end) |
| 359 | { |
| 360 | ERROR1 ("unexec: Specified bss_start (%u) is past end of program", |
| 361 | bss_start); |
| 362 | } |
| 363 | } |
| 364 | else |
| 365 | bss_start = bss_end; |
| 366 | |
| 367 | if (data_start > bss_start) /* Can't have negative data size. */ |
| 368 | { |
| 369 | ERROR2 ("unexec: data_start (%u) can't be greater than bss_start (%u)", |
| 370 | data_start, bss_start); |
| 371 | } |
| 372 | |
| 373 | #ifdef COFF |
| 374 | coff_offset = 0L; /* stays zero, except in DJGPP */ |
| 375 | |
| 376 | /* Salvage as much info from the existing file as possible */ |
| 377 | if (a_out >= 0) |
| 378 | { |
| 379 | #ifdef MSDOS |
| 380 | #if __DJGPP__ > 1 |
| 381 | /* Support the coff-go32-exe format with a prepended stub, since |
| 382 | this is what GCC 2.8.0 and later generates by default in DJGPP. */ |
| 383 | unsigned short mz_header[3]; |
| 384 | |
| 385 | if (read (a_out, &mz_header, sizeof (mz_header)) != sizeof (mz_header)) |
| 386 | { |
| 387 | PERROR (a_name); |
| 388 | } |
| 389 | if (mz_header[0] == 0x5a4d || mz_header[0] == 0x4d5a) /* "MZ" or "ZM" */ |
| 390 | { |
| 391 | coff_offset = (long)mz_header[2] * 512L; |
| 392 | if (mz_header[1]) |
| 393 | coff_offset += (long)mz_header[1] - 512L; |
| 394 | lseek (a_out, coff_offset, 0); |
| 395 | } |
| 396 | else |
| 397 | lseek (a_out, 0L, 0); |
| 398 | #endif /* __DJGPP__ > 1 */ |
| 399 | #endif /* MSDOS */ |
| 400 | if (read (a_out, &f_hdr, sizeof (f_hdr)) != sizeof (f_hdr)) |
| 401 | { |
| 402 | PERROR (a_name); |
| 403 | } |
| 404 | block_copy_start += sizeof (f_hdr); |
| 405 | if (f_hdr.f_opthdr > 0) |
| 406 | { |
| 407 | if (read (a_out, &f_ohdr, sizeof (f_ohdr)) != sizeof (f_ohdr)) |
| 408 | { |
| 409 | PERROR (a_name); |
| 410 | } |
| 411 | block_copy_start += sizeof (f_ohdr); |
| 412 | } |
| 413 | /* Loop through section headers, copying them in */ |
| 414 | lseek (a_out, coff_offset + sizeof (f_hdr) + f_hdr.f_opthdr, 0); |
| 415 | for (scns = f_hdr.f_nscns; scns > 0; scns--) { |
| 416 | if (read (a_out, &scntemp, sizeof (scntemp)) != sizeof (scntemp)) |
| 417 | { |
| 418 | PERROR (a_name); |
| 419 | } |
| 420 | if (scntemp.s_scnptr > 0L) |
| 421 | { |
| 422 | if (block_copy_start < scntemp.s_scnptr + scntemp.s_size) |
| 423 | block_copy_start = scntemp.s_scnptr + scntemp.s_size; |
| 424 | } |
| 425 | if (strcmp (scntemp.s_name, ".text") == 0) |
| 426 | { |
| 427 | f_thdr = scntemp; |
| 428 | } |
| 429 | else if (strcmp (scntemp.s_name, ".data") == 0) |
| 430 | { |
| 431 | f_dhdr = scntemp; |
| 432 | } |
| 433 | else if (strcmp (scntemp.s_name, ".bss") == 0) |
| 434 | { |
| 435 | f_bhdr = scntemp; |
| 436 | } |
| 437 | } |
| 438 | } |
| 439 | else |
| 440 | { |
| 441 | ERROR0 ("can't build a COFF file from scratch yet"); |
| 442 | } |
| 443 | |
| 444 | /* Now we alter the contents of all the f_*hdr variables |
| 445 | to correspond to what we want to dump. */ |
| 446 | |
| 447 | f_hdr.f_flags |= (F_RELFLG | F_EXEC); |
| 448 | #ifndef NO_REMAP |
| 449 | f_ohdr.text_start = (long) start_of_text (); |
| 450 | f_ohdr.tsize = data_start - f_ohdr.text_start; |
| 451 | f_ohdr.data_start = data_start; |
| 452 | #endif /* NO_REMAP */ |
| 453 | f_ohdr.dsize = bss_start - f_ohdr.data_start; |
| 454 | f_ohdr.bsize = bss_end - bss_start; |
| 455 | /* On some machines, the old values are right. |
| 456 | ??? Maybe on all machines with NO_REMAP. */ |
| 457 | f_thdr.s_size = f_ohdr.tsize; |
| 458 | f_thdr.s_scnptr = sizeof (f_hdr) + sizeof (f_ohdr); |
| 459 | f_thdr.s_scnptr += (f_hdr.f_nscns) * (sizeof (f_thdr)); |
| 460 | lnnoptr = f_thdr.s_lnnoptr; |
| 461 | #ifdef SECTION_ALIGNMENT |
| 462 | /* Some systems require special alignment |
| 463 | of the sections in the file itself. */ |
| 464 | f_thdr.s_scnptr |
| 465 | = (f_thdr.s_scnptr + SECTION_ALIGNMENT) & ~SECTION_ALIGNMENT; |
| 466 | #endif /* SECTION_ALIGNMENT */ |
| 467 | text_scnptr = f_thdr.s_scnptr; |
| 468 | f_dhdr.s_paddr = f_ohdr.data_start; |
| 469 | f_dhdr.s_vaddr = f_ohdr.data_start; |
| 470 | f_dhdr.s_size = f_ohdr.dsize; |
| 471 | f_dhdr.s_scnptr = f_thdr.s_scnptr + f_thdr.s_size; |
| 472 | #ifdef SECTION_ALIGNMENT |
| 473 | /* Some systems require special alignment |
| 474 | of the sections in the file itself. */ |
| 475 | f_dhdr.s_scnptr |
| 476 | = (f_dhdr.s_scnptr + SECTION_ALIGNMENT) & ~SECTION_ALIGNMENT; |
| 477 | #endif /* SECTION_ALIGNMENT */ |
| 478 | #ifdef DATA_SECTION_ALIGNMENT |
| 479 | /* Some systems require special alignment |
| 480 | of the data section only. */ |
| 481 | f_dhdr.s_scnptr |
| 482 | = (f_dhdr.s_scnptr + DATA_SECTION_ALIGNMENT) & ~DATA_SECTION_ALIGNMENT; |
| 483 | #endif /* DATA_SECTION_ALIGNMENT */ |
| 484 | data_scnptr = f_dhdr.s_scnptr; |
| 485 | f_bhdr.s_paddr = f_ohdr.data_start + f_ohdr.dsize; |
| 486 | f_bhdr.s_vaddr = f_ohdr.data_start + f_ohdr.dsize; |
| 487 | f_bhdr.s_size = f_ohdr.bsize; |
| 488 | f_bhdr.s_scnptr = 0L; |
| 489 | bias = f_dhdr.s_scnptr + f_dhdr.s_size - block_copy_start; |
| 490 | |
| 491 | if (f_hdr.f_symptr > 0L) |
| 492 | { |
| 493 | f_hdr.f_symptr += bias; |
| 494 | } |
| 495 | |
| 496 | if (f_thdr.s_lnnoptr > 0L) |
| 497 | { |
| 498 | f_thdr.s_lnnoptr += bias; |
| 499 | } |
| 500 | |
| 501 | #ifdef ADJUST_EXEC_HEADER |
| 502 | ADJUST_EXEC_HEADER; |
| 503 | #endif /* ADJUST_EXEC_HEADER */ |
| 504 | |
| 505 | if (write (new, &f_hdr, sizeof (f_hdr)) != sizeof (f_hdr)) |
| 506 | { |
| 507 | PERROR (new_name); |
| 508 | } |
| 509 | |
| 510 | if (write (new, &f_ohdr, sizeof (f_ohdr)) != sizeof (f_ohdr)) |
| 511 | { |
| 512 | PERROR (new_name); |
| 513 | } |
| 514 | |
| 515 | if (write (new, &f_thdr, sizeof (f_thdr)) != sizeof (f_thdr)) |
| 516 | { |
| 517 | PERROR (new_name); |
| 518 | } |
| 519 | |
| 520 | if (write (new, &f_dhdr, sizeof (f_dhdr)) != sizeof (f_dhdr)) |
| 521 | { |
| 522 | PERROR (new_name); |
| 523 | } |
| 524 | |
| 525 | if (write (new, &f_bhdr, sizeof (f_bhdr)) != sizeof (f_bhdr)) |
| 526 | { |
| 527 | PERROR (new_name); |
| 528 | } |
| 529 | |
| 530 | return (0); |
| 531 | |
| 532 | #else /* if not COFF */ |
| 533 | |
| 534 | /* Get symbol table info from header of a.out file if given one. */ |
| 535 | if (a_out >= 0) |
| 536 | { |
| 537 | if (read (a_out, &ohdr, sizeof hdr) != sizeof hdr) |
| 538 | { |
| 539 | PERROR (a_name); |
| 540 | } |
| 541 | |
| 542 | if (N_BADMAG (ohdr)) |
| 543 | { |
| 544 | ERROR1 ("invalid magic number in %s", a_name); |
| 545 | } |
| 546 | hdr = ohdr; |
| 547 | } |
| 548 | else |
| 549 | { |
| 550 | #ifdef MSDOS /* Demacs 1.1.1 91/10/16 HIRANO Satoshi */ |
| 551 | bzero ((void *)&hdr, sizeof hdr); |
| 552 | #else |
| 553 | bzero (&hdr, sizeof hdr); |
| 554 | #endif |
| 555 | } |
| 556 | |
| 557 | unexec_text_start = (long) start_of_text (); |
| 558 | unexec_data_start = data_start; |
| 559 | |
| 560 | /* Machine-dependent fixup for header, or maybe for unexec_text_start */ |
| 561 | #ifdef ADJUST_EXEC_HEADER |
| 562 | ADJUST_EXEC_HEADER; |
| 563 | #endif /* ADJUST_EXEC_HEADER */ |
| 564 | |
| 565 | hdr.a_trsize = 0; |
| 566 | hdr.a_drsize = 0; |
| 567 | if (entry_address != 0) |
| 568 | hdr.a_entry = entry_address; |
| 569 | |
| 570 | hdr.a_bss = bss_end - bss_start; |
| 571 | hdr.a_data = bss_start - data_start; |
| 572 | #ifdef NO_REMAP |
| 573 | hdr.a_text = ohdr.a_text; |
| 574 | #else /* not NO_REMAP */ |
| 575 | hdr.a_text = data_start - unexec_text_start; |
| 576 | |
| 577 | #ifdef A_TEXT_OFFSET |
| 578 | hdr.a_text += A_TEXT_OFFSET (ohdr); |
| 579 | #endif |
| 580 | |
| 581 | #endif /* not NO_REMAP */ |
| 582 | |
| 583 | if (write (new, &hdr, sizeof hdr) != sizeof hdr) |
| 584 | { |
| 585 | PERROR (new_name); |
| 586 | } |
| 587 | |
| 588 | #ifdef A_TEXT_OFFSET |
| 589 | hdr.a_text -= A_TEXT_OFFSET (ohdr); |
| 590 | #endif |
| 591 | |
| 592 | return 0; |
| 593 | |
| 594 | #endif /* not COFF */ |
| 595 | } |
| 596 | \f |
| 597 | write_segment (new, ptr, end) |
| 598 | int new; |
| 599 | register char *ptr, *end; |
| 600 | { |
| 601 | register int i, nwrite, ret; |
| 602 | char buf[80]; |
| 603 | #ifndef USE_CRT_DLL |
| 604 | extern int errno; |
| 605 | #endif |
| 606 | /* This is the normal amount to write at once. |
| 607 | It is the size of block that NFS uses. */ |
| 608 | int writesize = 1 << 13; |
| 609 | int pagesize = getpagesize (); |
| 610 | char zeros[1 << 13]; |
| 611 | |
| 612 | bzero (zeros, sizeof (zeros)); |
| 613 | |
| 614 | for (i = 0; ptr < end;) |
| 615 | { |
| 616 | /* Distance to next multiple of writesize. */ |
| 617 | nwrite = (((int) ptr + writesize) & -writesize) - (int) ptr; |
| 618 | /* But not beyond specified end. */ |
| 619 | if (nwrite > end - ptr) nwrite = end - ptr; |
| 620 | ret = write (new, ptr, nwrite); |
| 621 | /* If write gets a page fault, it means we reached |
| 622 | a gap between the old text segment and the old data segment. |
| 623 | This gap has probably been remapped into part of the text segment. |
| 624 | So write zeros for it. */ |
| 625 | if (ret == -1 |
| 626 | #ifdef EFAULT |
| 627 | && errno == EFAULT |
| 628 | #endif |
| 629 | ) |
| 630 | { |
| 631 | /* Write only a page of zeros at once, |
| 632 | so that we we don't overshoot the start |
| 633 | of the valid memory in the old data segment. */ |
| 634 | if (nwrite > pagesize) |
| 635 | nwrite = pagesize; |
| 636 | write (new, zeros, nwrite); |
| 637 | } |
| 638 | #if 0 /* Now that we have can ask `write' to write more than a page, |
| 639 | it is legit for write do less than the whole amount specified. */ |
| 640 | else if (nwrite != ret) |
| 641 | { |
| 642 | sprintf (buf, |
| 643 | "unexec write failure: addr 0x%x, fileno %d, size 0x%x, wrote 0x%x, errno %d", |
| 644 | ptr, new, nwrite, ret, errno); |
| 645 | PERROR (buf); |
| 646 | } |
| 647 | #endif |
| 648 | i += nwrite; |
| 649 | ptr += nwrite; |
| 650 | } |
| 651 | } |
| 652 | /* **************************************************************** |
| 653 | * copy_text_and_data |
| 654 | * |
| 655 | * Copy the text and data segments from memory to the new a.out |
| 656 | */ |
| 657 | static int |
| 658 | copy_text_and_data (new, a_out) |
| 659 | int new, a_out; |
| 660 | { |
| 661 | register char *end; |
| 662 | register char *ptr; |
| 663 | |
| 664 | #ifdef COFF |
| 665 | |
| 666 | #ifdef MSDOS |
| 667 | #if __DJGPP__ >= 2 |
| 668 | /* Dump the original table of exception handlers, not the one |
| 669 | where our exception hooks are registered. */ |
| 670 | __djgpp_exception_toggle (); |
| 671 | |
| 672 | /* Switch off startup flags that might have been set at runtime |
| 673 | and which might change the way that dumped Emacs works. */ |
| 674 | save_djgpp_startup_flags = _crt0_startup_flags; |
| 675 | _crt0_startup_flags &= ~(_CRT0_FLAG_NO_LFN | _CRT0_FLAG_NEARPTR); |
| 676 | #endif |
| 677 | #endif |
| 678 | |
| 679 | lseek (new, (long) text_scnptr, 0); |
| 680 | ptr = (char *) f_ohdr.text_start; |
| 681 | end = ptr + f_ohdr.tsize; |
| 682 | write_segment (new, ptr, end); |
| 683 | |
| 684 | lseek (new, (long) data_scnptr, 0); |
| 685 | ptr = (char *) f_ohdr.data_start; |
| 686 | end = ptr + f_ohdr.dsize; |
| 687 | write_segment (new, ptr, end); |
| 688 | |
| 689 | #ifdef MSDOS |
| 690 | #if __DJGPP__ >= 2 |
| 691 | /* Restore our exception hooks. */ |
| 692 | __djgpp_exception_toggle (); |
| 693 | |
| 694 | /* Restore the startup flags. */ |
| 695 | _crt0_startup_flags = save_djgpp_startup_flags; |
| 696 | #endif |
| 697 | #endif |
| 698 | |
| 699 | #else /* if not COFF */ |
| 700 | |
| 701 | /* Some machines count the header as part of the text segment. |
| 702 | That is to say, the header appears in core |
| 703 | just before the address that start_of_text returns. |
| 704 | For them, N_TXTOFF is the place where the header goes. |
| 705 | We must adjust the seek to the place after the header. |
| 706 | Note that at this point hdr.a_text does *not* count |
| 707 | the extra A_TEXT_OFFSET bytes, only the actual bytes of code. */ |
| 708 | |
| 709 | #ifdef A_TEXT_SEEK |
| 710 | lseek (new, (long) A_TEXT_SEEK (hdr), 0); |
| 711 | #else |
| 712 | lseek (new, (long) N_TXTOFF (hdr), 0); |
| 713 | #endif /* no A_TEXT_SEEK */ |
| 714 | |
| 715 | ptr = (char *) unexec_text_start; |
| 716 | end = ptr + hdr.a_text; |
| 717 | write_segment (new, ptr, end); |
| 718 | |
| 719 | ptr = (char *) unexec_data_start; |
| 720 | end = ptr + hdr.a_data; |
| 721 | /* This lseek is certainly incorrect when A_TEXT_OFFSET |
| 722 | and I believe it is a no-op otherwise. |
| 723 | Let's see if its absence ever fails. */ |
| 724 | /* lseek (new, (long) N_TXTOFF (hdr) + hdr.a_text, 0); */ |
| 725 | write_segment (new, ptr, end); |
| 726 | |
| 727 | #endif /* not COFF */ |
| 728 | |
| 729 | return 0; |
| 730 | } |
| 731 | \f |
| 732 | /* **************************************************************** |
| 733 | * copy_sym |
| 734 | * |
| 735 | * Copy the relocation information and symbol table from the a.out to the new |
| 736 | */ |
| 737 | static int |
| 738 | copy_sym (new, a_out, a_name, new_name) |
| 739 | int new, a_out; |
| 740 | char *a_name, *new_name; |
| 741 | { |
| 742 | char page[1024]; |
| 743 | int n; |
| 744 | |
| 745 | if (a_out < 0) |
| 746 | return 0; |
| 747 | |
| 748 | #ifdef COFF |
| 749 | if (SYMS_START == 0L) |
| 750 | return 0; |
| 751 | #endif /* COFF */ |
| 752 | |
| 753 | #ifdef COFF |
| 754 | if (lnnoptr) /* if there is line number info */ |
| 755 | lseek (a_out, coff_offset + lnnoptr, 0); /* start copying from there */ |
| 756 | else |
| 757 | lseek (a_out, coff_offset + SYMS_START, 0); /* Position a.out to symtab. */ |
| 758 | #else /* not COFF */ |
| 759 | lseek (a_out, SYMS_START, 0); /* Position a.out to symtab. */ |
| 760 | #endif /* not COFF */ |
| 761 | |
| 762 | while ((n = read (a_out, page, sizeof page)) > 0) |
| 763 | { |
| 764 | if (write (new, page, n) != n) |
| 765 | { |
| 766 | PERROR (new_name); |
| 767 | } |
| 768 | } |
| 769 | if (n < 0) |
| 770 | { |
| 771 | PERROR (a_name); |
| 772 | } |
| 773 | return 0; |
| 774 | } |
| 775 | \f |
| 776 | /* **************************************************************** |
| 777 | * mark_x |
| 778 | * |
| 779 | * After successfully building the new a.out, mark it executable |
| 780 | */ |
| 781 | static void |
| 782 | mark_x (name) |
| 783 | char *name; |
| 784 | { |
| 785 | struct stat sbuf; |
| 786 | int um; |
| 787 | int new = 0; /* for PERROR */ |
| 788 | |
| 789 | um = umask (777); |
| 790 | umask (um); |
| 791 | if (stat (name, &sbuf) == -1) |
| 792 | { |
| 793 | PERROR (name); |
| 794 | } |
| 795 | sbuf.st_mode |= 0111 & ~um; |
| 796 | if (chmod (name, sbuf.st_mode) == -1) |
| 797 | PERROR (name); |
| 798 | } |
| 799 | \f |
| 800 | #ifdef COFF |
| 801 | #ifndef COFF_BSD_SYMBOLS |
| 802 | |
| 803 | /* |
| 804 | * If the COFF file contains a symbol table and a line number section, |
| 805 | * then any auxiliary entries that have values for x_lnnoptr must |
| 806 | * be adjusted by the amount that the line number section has moved |
| 807 | * in the file (bias computed in make_hdr). The #@$%&* designers of |
| 808 | * the auxiliary entry structures used the absolute file offsets for |
| 809 | * the line number entry rather than an offset from the start of the |
| 810 | * line number section! |
| 811 | * |
| 812 | * When I figure out how to scan through the symbol table and pick out |
| 813 | * the auxiliary entries that need adjustment, this routine will |
| 814 | * be fixed. As it is now, all such entries are wrong and sdb |
| 815 | * will complain. Fred Fish, UniSoft Systems Inc. |
| 816 | */ |
| 817 | |
| 818 | /* This function is probably very slow. Instead of reopening the new |
| 819 | file for input and output it should copy from the old to the new |
| 820 | using the two descriptors already open (WRITEDESC and READDESC). |
| 821 | Instead of reading one small structure at a time it should use |
| 822 | a reasonable size buffer. But I don't have time to work on such |
| 823 | things, so I am installing it as submitted to me. -- RMS. */ |
| 824 | |
| 825 | adjust_lnnoptrs (writedesc, readdesc, new_name) |
| 826 | int writedesc; |
| 827 | int readdesc; |
| 828 | char *new_name; |
| 829 | { |
| 830 | register int nsyms; |
| 831 | register int new; |
| 832 | struct syment symentry; |
| 833 | union auxent auxentry; |
| 834 | |
| 835 | if (!lnnoptr || !f_hdr.f_symptr) |
| 836 | return 0; |
| 837 | |
| 838 | #ifdef MSDOS |
| 839 | if ((new = writedesc) < 0) |
| 840 | #else |
| 841 | if ((new = open (new_name, O_RDWR)) < 0) |
| 842 | #endif |
| 843 | { |
| 844 | PERROR (new_name); |
| 845 | return -1; |
| 846 | } |
| 847 | |
| 848 | lseek (new, f_hdr.f_symptr, 0); |
| 849 | for (nsyms = 0; nsyms < f_hdr.f_nsyms; nsyms++) |
| 850 | { |
| 851 | read (new, &symentry, SYMESZ); |
| 852 | if (symentry.n_numaux) |
| 853 | { |
| 854 | read (new, &auxentry, AUXESZ); |
| 855 | nsyms++; |
| 856 | if (ISFCN (symentry.n_type) || symentry.n_type == 0x2400) |
| 857 | { |
| 858 | auxentry.x_sym.x_fcnary.x_fcn.x_lnnoptr += bias; |
| 859 | lseek (new, -AUXESZ, 1); |
| 860 | write (new, &auxentry, AUXESZ); |
| 861 | } |
| 862 | } |
| 863 | } |
| 864 | #ifndef MSDOS |
| 865 | close (new); |
| 866 | #endif |
| 867 | return 0; |
| 868 | } |
| 869 | |
| 870 | #endif /* COFF_BSD_SYMBOLS */ |
| 871 | |
| 872 | #endif /* COFF */ |
| 873 | |
| 874 | /* **************************************************************** |
| 875 | * unexec |
| 876 | * |
| 877 | * driving logic. |
| 878 | */ |
| 879 | unexec (new_name, a_name, data_start, bss_start, entry_address) |
| 880 | char *new_name, *a_name; |
| 881 | unsigned data_start, bss_start, entry_address; |
| 882 | { |
| 883 | int new, a_out = -1; |
| 884 | |
| 885 | if (a_name && (a_out = open (a_name, O_RDONLY)) < 0) |
| 886 | { |
| 887 | PERROR (a_name); |
| 888 | } |
| 889 | if ((new = creat (new_name, 0666)) < 0) |
| 890 | { |
| 891 | PERROR (new_name); |
| 892 | } |
| 893 | |
| 894 | if (make_hdr (new, a_out, data_start, bss_start, entry_address, a_name, new_name) < 0 |
| 895 | || copy_text_and_data (new, a_out) < 0 |
| 896 | || copy_sym (new, a_out, a_name, new_name) < 0 |
| 897 | #ifdef COFF |
| 898 | #ifndef COFF_BSD_SYMBOLS |
| 899 | || adjust_lnnoptrs (new, a_out, new_name) < 0 |
| 900 | #endif |
| 901 | #endif |
| 902 | ) |
| 903 | { |
| 904 | close (new); |
| 905 | /* unlink (new_name); /* Failed, unlink new a.out */ |
| 906 | return -1; |
| 907 | } |
| 908 | |
| 909 | close (new); |
| 910 | if (a_out >= 0) |
| 911 | close (a_out); |
| 912 | mark_x (new_name); |
| 913 | return 0; |
| 914 | } |
| 915 | |
| 916 | #endif /* not CANNOT_DUMP */ |
| 917 | |
| 918 | /* arch-tag: 62409b69-e27a-4a7c-9413-0210d6b54e7f |
| 919 | (do not change this comment) */ |