Mercurial > hg > xemacs-beta
annotate src/unexhp9k800.c @ 5450:8c406331e77e
Copyright and license to src/s/sol2.h.
| author | Mats Lidell <matsl@xemacs.org> |
|---|---|
| date | Thu, 06 Jan 2011 01:31:43 +0100 |
| parents | 308d34e9f07d |
| children | 90dcf2376909 |
| rev | line source |
|---|---|
| 428 | 1 /* Unexec for HP 9000 Series 800 machines. |
| 2 Bob Desinger <hpsemc!bd@hplabs.hp.com> | |
| 3 | |
| 4 This file is part of XEmacs. | |
| 5 | |
|
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6 XEmacs is free software: you can redistribute it and/or modify it |
| 428 | 7 under the terms of the GNU General Public License as published by the |
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8 Free Software Foundation, either version 3 of the License, or (at your |
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9 option) any later version. |
| 428 | 10 |
| 11 XEmacs is distributed in the hope that it will be useful, but WITHOUT | |
| 12 ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or | |
| 13 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License | |
| 14 for more details. | |
| 15 | |
| 16 You should have received a copy of the GNU General Public License | |
|
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17 along with XEmacs. If not, see <http://www.gnu.org/licenses/>. */ |
| 428 | 18 |
| 19 /* Synched up with: Not synched with FSF. */ | |
| 20 | |
| 21 /* | |
| 22 | |
| 23 Unexec creates a copy of the old a.out file, and replaces the old data | |
| 24 area with the current data area. When the new file is executed, the | |
| 25 process will see the same data structures and data values that the | |
| 26 original process had when unexec was called. | |
| 27 | |
| 28 Unlike other versions of unexec, this one copies symbol table and | |
| 29 debug information to the new a.out file. Thus, the new a.out file | |
| 30 may be debugged with symbolic debuggers. | |
| 31 | |
| 32 If you fix any bugs in this, I'd like to incorporate your fixes. | |
| 33 Send them to uunet!hpda!hpsemc!jmorris or jmorris%hpsemc@hplabs.HP.COM. | |
| 34 | |
| 35 CAVEATS: | |
| 36 This routine saves the current value of all static and external | |
| 37 variables. This means that any data structure that needs to be | |
| 38 initialized must be explicitly reset. Variables will not have their | |
| 39 expected default values. | |
| 40 | |
| 41 Unfortunately, the HP-UX signal handler has internal initialization | |
| 42 flags which are not explicitly reset. Thus, for signals to work in | |
| 43 conjunction with this routine, the following code must executed when | |
| 44 the new process starts up. | |
| 45 | |
| 46 void _sigreturn(); | |
| 47 ... | |
| 48 sigsetreturn(_sigreturn); | |
| 49 */ | |
| 50 | |
| 51 | |
| 52 #include <config.h> | |
| 430 | 53 #include <stdlib.h> |
| 428 | 54 #include <stdio.h> |
| 55 #include <fcntl.h> | |
| 56 #include <errno.h> | |
| 57 | |
| 58 #include <a.out.h> | |
| 442 | 59 #include "lisp.h" |
| 428 | 60 |
| 61 /* | |
| 62 * Minor modification to enable dumping with shared libraries added by | |
| 63 * Dipankar Gupta (dg@hplb.hpl.hp.com). I studied Oliver Laumann's | |
| 64 * more elaborate dynamic loading scheme in ELK while implementing | |
| 65 * this, but don't use any of his machinery. | |
| 66 * | |
| 67 * Stores the BRK value at dump time, and uses the RUN_TIME_REMAP hook | |
| 68 * to break back to the stored value when the dumped executable is restarted. | |
| 69 * | |
| 70 * CAVEATS (addenda): | |
| 71 * 1. Text area of the shlibs are not stored. Thus, if a shared library is | |
| 72 * replaced between the time of dump and execution, all bets are off. | |
| 73 * | |
| 74 * 2. Assumes that the data and bss area are adjacent, which is true of the | |
| 75 * current VM implementation. | |
| 76 * | |
| 77 * 3. Any setup that defines HPUX_USE_SHLIBS *must* also define | |
| 78 * RUN_TIME_REMAP. | |
| 79 */ | |
| 80 | |
| 81 #ifdef HPUX_USE_SHLIBS | |
| 82 #include <dl.h> /* User-space dynamic loader entry points */ | |
| 442 | 83 static void Save_Shared_Data (void); |
| 84 static void Restore_Shared_Data (void); | |
| 428 | 85 #endif |
| 86 | |
| 87 void write_header(int file, struct header *hdr, struct som_exec_auxhdr *auxhdr); | |
| 88 void read_header (int file, struct header *hdr, struct som_exec_auxhdr *auxhdr); | |
| 89 void save_data_space (int file, struct header *hdr, | |
| 90 struct som_exec_auxhdr *auxhdr, int size); | |
| 3025 | 91 void copy_rest (int old, int new_); |
| 92 void copy_file (int old, int new_, int size); | |
| 428 | 93 void update_file_ptrs(int file, struct header *hdr, |
| 94 struct som_exec_auxhdr *auxhdr, | |
| 95 unsigned int location, int offset); | |
| 96 int calculate_checksum(struct header *hdr); | |
| 97 | |
| 98 /* Create a new a.out file, same as old but with current data space */ | |
| 99 int | |
| 442 | 100 unexec (char *new_name, /* name of the new a.out file to be created */ |
| 101 char *old_name, /* name of the old a.out file */ | |
| 2286 | 102 uintptr_t UNUSED (new_end_of_text), /* ptr to new edata/etext */ |
| 103 uintptr_t UNUSED (dummy1), /* not used by emacs */ | |
| 104 uintptr_t UNUSED (dummy2)) | |
| 428 | 105 { |
| 3025 | 106 int old, new_; |
| 428 | 107 int old_size, new_size; |
| 108 struct header hdr; | |
| 109 struct som_exec_auxhdr auxhdr; | |
| 110 long i; | |
| 111 | |
| 112 /* For the greatest flexibility, should create a temporary file in | |
| 113 the same directory as the new file. When everything is complete, | |
| 114 rename the temp file to the new name. | |
| 115 This way, a program could update its own a.out file even while | |
| 116 it is still executing. If problems occur, everything is still | |
| 117 intact. NOT implemented. */ | |
| 118 | |
| 119 /* Open the input and output a.out files */ | |
| 120 old = open (old_name, O_RDONLY); | |
| 121 if (old < 0) | |
| 122 { perror(old_name); exit(1); } | |
| 3025 | 123 new_ = open (new_name, O_CREAT|O_RDWR|O_TRUNC, 0777); |
| 124 if (new_ < 0) | |
| 428 | 125 { perror(new_name); exit(1); } |
| 126 | |
| 127 /* Read the old headers */ | |
| 128 read_header(old, &hdr, &auxhdr); | |
| 129 | |
| 130 #ifdef HPUX_USE_SHLIBS | |
| 131 Save_Shared_Data(); /* Save break value (added: dg@hplb.hpl.hp.com) */ | |
| 132 #endif | |
| 133 /* Decide how large the new and old data areas are */ | |
| 134 old_size = auxhdr.exec_dsize; | |
| 135 /* I suspect these two statements are separate | |
| 136 to avoid a compiler bug in hpux version 8. */ | |
| 137 i = (long) sbrk (0); | |
| 138 new_size = i - auxhdr.exec_dmem; | |
| 139 | |
| 140 /* Copy the old file to the new, up to the data space */ | |
| 141 lseek(old, 0, 0); | |
| 3025 | 142 copy_file(old, new_, auxhdr.exec_dfile); |
| 428 | 143 |
| 144 /* Skip the old data segment and write a new one */ | |
| 145 lseek(old, old_size, 1); | |
| 3025 | 146 save_data_space(new_, &hdr, &auxhdr, new_size); |
| 428 | 147 |
| 148 /* Copy the rest of the file */ | |
| 3025 | 149 copy_rest(old, new_); |
| 428 | 150 |
| 151 /* Update file pointers since we probably changed size of data area */ | |
| 3025 | 152 update_file_ptrs(new_, &hdr, &auxhdr, auxhdr.exec_dfile, new_size-old_size); |
| 428 | 153 |
| 154 /* Save the modified header */ | |
| 3025 | 155 write_header(new_, &hdr, &auxhdr); |
| 428 | 156 |
| 157 /* Close the binary file */ | |
| 158 close (old); | |
| 3025 | 159 close (new_); |
| 428 | 160 return 0; |
| 161 } | |
| 162 | |
| 163 /* Save current data space in the file, update header. */ | |
| 164 | |
| 165 void | |
| 2286 | 166 save_data_space (int file, struct header *UNUSED (hdr), |
| 428 | 167 struct som_exec_auxhdr *auxhdr, int size) |
| 168 { | |
| 169 /* Write the entire data space out to the file */ | |
| 170 if (write(file, (void *)auxhdr->exec_dmem, size) != size) | |
| 171 { perror("Can't save new data space"); exit(1); } | |
| 172 | |
| 173 /* Update the header to reflect the new data size */ | |
| 174 auxhdr->exec_dsize = size; | |
| 175 auxhdr->exec_bsize = 0; | |
| 176 } | |
| 177 | |
| 178 /* Update the values of file pointers when something is inserted. */ | |
| 179 | |
| 180 void | |
| 181 update_file_ptrs(int file, struct header *hdr, | |
| 182 struct som_exec_auxhdr *auxhdr, | |
| 183 unsigned int location, int offset) | |
| 184 { | |
| 185 struct subspace_dictionary_record subspace; | |
| 186 int i; | |
| 187 | |
| 188 /* Increase the overall size of the module */ | |
| 189 hdr->som_length += offset; | |
| 190 | |
| 191 /* Update the various file pointers in the header */ | |
| 192 #define update(ptr) if (ptr > location) ptr = ptr + offset | |
| 193 update(hdr->aux_header_location); | |
| 194 update(hdr->space_strings_location); | |
| 195 update(hdr->init_array_location); | |
| 196 update(hdr->compiler_location); | |
| 197 update(hdr->symbol_location); | |
| 198 update(hdr->fixup_request_location); | |
| 199 update(hdr->symbol_strings_location); | |
| 200 update(hdr->unloadable_sp_location); | |
| 201 update(auxhdr->exec_tfile); | |
| 202 update(auxhdr->exec_dfile); | |
| 203 | |
| 204 /* Do for each subspace dictionary entry */ | |
| 205 lseek(file, hdr->subspace_location, 0); | |
| 206 for (i = 0; i < hdr->subspace_total; i++) | |
| 207 { | |
| 208 if (read(file, &subspace, sizeof(subspace)) != sizeof(subspace)) | |
| 209 { perror("Can't read subspace record"); exit(1); } | |
| 210 | |
| 211 /* If subspace has a file location, update it */ | |
| 212 if (subspace.initialization_length > 0 | |
| 213 && subspace.file_loc_init_value > location) | |
| 214 { | |
| 215 subspace.file_loc_init_value += offset; | |
| 216 lseek(file, -sizeof(subspace), 1); | |
| 217 if (write(file, &subspace, sizeof(subspace)) != sizeof(subspace)) | |
| 218 { perror("Can't update subspace record"); exit(1); } | |
| 219 } | |
| 220 } | |
| 221 | |
| 222 /* Do for each initialization pointer record */ | |
| 223 /* (I don't think it applies to executable files, only relocatables) */ | |
| 224 #undef update | |
| 225 } | |
| 226 | |
| 227 /* Read in the header records from an a.out file. */ | |
| 228 | |
| 229 void | |
| 230 read_header(int file, struct header *hdr, struct som_exec_auxhdr *auxhdr) | |
| 231 { | |
| 232 | |
| 233 /* Read the header in */ | |
| 234 lseek(file, 0, 0); | |
| 235 if (read(file, hdr, sizeof(*hdr)) != sizeof(*hdr)) | |
| 236 { perror("Couldn't read header from a.out file"); exit(1); } | |
| 237 | |
| 238 if (hdr->a_magic != EXEC_MAGIC && hdr->a_magic != SHARE_MAGIC | |
| 239 && hdr->a_magic != DEMAND_MAGIC) | |
| 240 { | |
| 241 fprintf(stderr, "a.out file doesn't have legal magic number\n"); | |
| 242 exit(1); | |
| 243 } | |
| 244 | |
| 245 lseek(file, hdr->aux_header_location, 0); | |
| 246 if (read(file, auxhdr, sizeof(*auxhdr)) != sizeof(*auxhdr)) | |
| 247 { | |
| 248 perror("Couldn't read auxiliary header from a.out file"); | |
| 249 exit(1); | |
| 250 } | |
| 251 } | |
| 252 | |
| 253 /* Write out the header records into an a.out file. */ | |
| 254 void | |
| 255 write_header(int file, struct header *hdr, struct som_exec_auxhdr *auxhdr) | |
| 256 { | |
| 257 /* Update the checksum */ | |
| 258 hdr->checksum = calculate_checksum(hdr); | |
| 259 | |
| 260 /* Write the header back into the a.out file */ | |
| 261 lseek(file, 0, 0); | |
| 262 if (write(file, hdr, sizeof(*hdr)) != sizeof(*hdr)) | |
| 263 { perror("Couldn't write header to a.out file"); exit(1); } | |
| 264 lseek(file, hdr->aux_header_location, 0); | |
| 265 if (write(file, auxhdr, sizeof(*auxhdr)) != sizeof(*auxhdr)) | |
| 266 { perror("Couldn't write auxiliary header to a.out file"); exit(1); } | |
| 267 } | |
| 268 | |
| 269 /* Calculate the checksum of a SOM header record. */ | |
| 270 int | |
| 271 calculate_checksum(struct header *hdr) | |
| 272 { | |
| 273 int checksum, i, *ptr; | |
| 274 | |
| 275 checksum = 0; ptr = (int *) hdr; | |
| 276 | |
| 277 for (i=0; i<sizeof(*hdr)/sizeof(int)-1; i++) | |
| 278 checksum ^= ptr[i]; | |
| 279 | |
| 280 return(checksum); | |
| 281 } | |
| 282 | |
| 283 /* Copy size bytes from the old file to the new one. */ | |
| 284 void | |
| 3025 | 285 copy_file (int old, int new_, int size) |
| 428 | 286 { |
| 287 int len; | |
| 288 int buffer[8192]; /* word aligned will be faster */ | |
| 289 | |
| 290 for (; size > 0; size -= len) | |
| 291 { | |
| 442 | 292 len = size < sizeof (buffer) ? size : sizeof (buffer); |
| 293 if (read (old, buffer, len) != len) | |
| 294 { | |
| 295 perror ("Read failure on a.out file"); | |
| 296 exit (1); | |
| 297 } | |
| 3025 | 298 if (write (new_, buffer, len) != len) |
| 442 | 299 { |
| 300 perror ("Write failure in a.out file"); | |
| 301 exit (1); | |
| 302 } | |
| 428 | 303 } |
| 304 } | |
| 305 | |
| 306 /* Copy the rest of the file, up to EOF. */ | |
| 307 void | |
| 3025 | 308 copy_rest (int old, int new_) |
| 428 | 309 { |
| 310 int buffer[4096]; | |
| 311 int len; | |
| 312 | |
| 313 /* Copy bytes until end of file or error */ | |
| 314 while ( (len = read(old, buffer, sizeof(buffer))) > 0) | |
| 3025 | 315 if (write(new_, buffer, len) != len) break; |
| 428 | 316 |
| 317 if (len != 0) | |
| 318 { perror("Unable to copy the rest of the file"); exit(1); } | |
| 319 } | |
| 320 | |
| 321 #ifdef DEBUG | |
| 322 display_header(struct header *hdr, struct som_exec_auxhdr *auxhdr) | |
| 323 { | |
| 324 /* Display the header information (debug) */ | |
| 325 printf("\n\nFILE HEADER\n"); | |
| 326 printf("magic number %d \n", hdr->a_magic); | |
| 327 printf("text loc %.8x size %d \n", auxhdr->exec_tmem, auxhdr->exec_tsize); | |
| 328 printf("data loc %.8x size %d \n", auxhdr->exec_dmem, auxhdr->exec_dsize); | |
| 329 printf("entry %x \n", auxhdr->exec_entry); | |
| 330 printf("Bss segment size %u\n", auxhdr->exec_bsize); | |
| 331 printf("\n"); | |
| 332 printf("data file loc %d size %d\n", | |
| 333 auxhdr->exec_dfile, auxhdr->exec_dsize); | |
| 334 printf("som_length %d\n", hdr->som_length); | |
| 335 printf("unloadable sploc %d size %d\n", | |
| 336 hdr->unloadable_sp_location, hdr->unloadable_sp_size); | |
| 337 } | |
| 338 #endif /* DEBUG */ | |
| 339 | |
| 340 #ifdef HPUX_USE_SHLIBS | |
| 341 /* Added machinery for shared libs... see comments at the beginning of this file. */ | |
| 342 | |
| 343 void *Brk_On_Dump = 0; /* Brk value to restore... stored as a global */ | |
| 344 | |
| 442 | 345 static void |
| 346 Save_Shared_Data (void) | |
| 347 { | |
| 348 Brk_On_Dump = sbrk (0); | |
| 428 | 349 } |
| 350 | |
| 442 | 351 static void |
| 352 Restore_Shared_Data (void) | |
| 353 { | |
| 354 brk (Brk_On_Dump); | |
| 428 | 355 } |
| 356 | |
| 357 /* run_time_remap is the magic called by startup code in the dumped executable | |
| 442 | 358 if RUN_TIME_REMAP is set. */ |
| 359 int | |
| 2286 | 360 run_time_remap (char *UNUSED (dummy)) |
| 442 | 361 { |
| 362 Restore_Shared_Data (); | |
| 363 return 0; | |
| 364 } | |
| 428 | 365 #endif /* HPUX_USE_SHLIBS */ |