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e0f712ba AC |
1 | /* Dump Emacs in Mach-O format for use on Mac OS X. |
2 | Copyright (C) 2001, 2002 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 2, or (at your option) | |
9 | 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; see the file COPYING. If not, write to | |
18 | the Free Software Foundation, Inc., 59 Temple Place - Suite 330, | |
19 | Boston, MA 02111-1307, USA. */ | |
20 | ||
21 | /* Contributed by Andrew Choi (akochoi@mac.com). */ | |
22 | ||
23 | /* Documentation note. | |
24 | ||
25 | Consult the following documents/files for a description of the | |
26 | Mach-O format: the file loader.h, man pages for Mach-O and ld, old | |
27 | NEXTSTEP documents of the Mach-O format. The tool otool dumps the | |
28 | mach header (-h option) and the load commands (-l option) in a | |
29 | Mach-O file. The tool nm on Mac OS X displays the symbol table in | |
30 | a Mach-O file. For examples of unexec for the Mach-O format, see | |
31 | the file unexnext.c in the GNU Emacs distribution, the file | |
32 | unexdyld.c in the Darwin port of GNU Emacs 20.7, and unexdyld.c in | |
33 | the Darwin port of XEmacs 21.1. Also the Darwin Libc source | |
34 | contains the source code for malloc_freezedry and malloc_jumpstart. | |
35 | Read that to see what they do. This file was written completely | |
36 | from scratch, making use of information from the above sources. */ | |
37 | ||
38 | /* The Mac OS X implementation of unexec makes use of Darwin's `zone' | |
39 | memory allocator. All calls to malloc, realloc, and free in Emacs | |
40 | are redirected to unexec_malloc, unexec_realloc, and unexec_free in | |
41 | this file. When temacs is run, all memory requests are handled in | |
42 | the zone EmacsZone. The Darwin memory allocator library calls | |
43 | maintain the data structures to manage this zone. Dumping writes | |
44 | its contents to data segments of the executable file. When emacs | |
45 | is run, the loader recreates the contents of the zone in memory. | |
46 | However since the initialization routine of the zone memory | |
47 | allocator is run again, this `zone' can no longer be used as a | |
48 | heap. That is why emacs uses the ordinary malloc system call to | |
49 | allocate memory. Also, when a block of memory needs to be | |
50 | reallocated and the new size is larger than the old one, a new | |
51 | block must be obtained by malloc and the old contents copied to | |
52 | it. */ | |
53 | ||
54 | /* Peculiarity of the Mach-O files generated by ld in Mac OS X | |
55 | (possible causes of future bugs if changed). | |
56 | ||
57 | The file offset of the start of the __TEXT segment is zero. Since | |
58 | the Mach header and load commands are located at the beginning of a | |
59 | Mach-O file, copying the contents of the __TEXT segment from the | |
60 | input file overwrites them in the output file. Despite this, | |
61 | unexec works fine as written below because the segment load command | |
62 | for __TEXT appears, and is therefore processed, before all other | |
63 | load commands except the segment load command for __PAGEZERO, which | |
64 | remains unchanged. | |
65 | ||
66 | Although the file offset of the start of the __TEXT segment is | |
67 | zero, none of the sections it contains actually start there. In | |
68 | fact, the earliest one starts a few hundred bytes beyond the end of | |
69 | the last load command. The linker option -headerpad controls the | |
70 | minimum size of this padding. Its setting can be changed in | |
71 | s/darwin.h. A value of 0x300, e.g., leaves room for about 15 | |
72 | additional load commands for the newly created __DATA segments (at | |
73 | 56 bytes each). Unexec fails if there is not enough room for these | |
74 | new segments. | |
75 | ||
76 | The __TEXT segment contains the sections __text, __cstring, | |
77 | __picsymbol_stub, and __const and the __DATA segment contains the | |
78 | sections __data, __la_symbol_ptr, __nl_symbol_ptr, __dyld, __bss, | |
79 | and __common. The other segments do not contain any sections. | |
80 | These sections are copied from the input file to the output file, | |
81 | except for __data, __bss, and __common, which are dumped from | |
82 | memory. The types of the sections __bss and __common are changed | |
83 | from S_ZEROFILL to S_REGULAR. Note that the number of sections and | |
84 | their relative order in the input and output files remain | |
85 | unchanged. Otherwise all n_sect fields in the nlist records in the | |
86 | symbol table (specified by the LC_SYMTAB load command) will have to | |
87 | be changed accordingly. | |
88 | */ | |
89 | ||
90 | #include <stdio.h> | |
91 | #include <stdlib.h> | |
92 | #include <fcntl.h> | |
93 | #include <stdarg.h> | |
94 | #include <sys/types.h> | |
95 | #include <unistd.h> | |
96 | #include <mach/mach.h> | |
97 | #include <mach-o/loader.h> | |
6b61353c KH |
98 | #include <mach-o/reloc.h> |
99 | #if defined (__ppc__) | |
100 | #include <mach-o/ppc/reloc.h> | |
101 | #endif | |
e0f712ba AC |
102 | #include <objc/malloc.h> |
103 | ||
104 | #define VERBOSE 1 | |
105 | ||
106 | /* Size of buffer used to copy data from the input file to the output | |
107 | file in function unexec_copy. */ | |
108 | #define UNEXEC_COPY_BUFSZ 1024 | |
109 | ||
110 | /* Regions with memory addresses above this value are assumed to be | |
111 | mapped to dynamically loaded libraries and will not be dumped. */ | |
112 | #define VM_DATA_TOP (20 * 1024 * 1024) | |
113 | ||
114 | /* Used by malloc_freezedry and malloc_jumpstart. */ | |
115 | int malloc_cookie; | |
116 | ||
117 | /* Type of an element on the list of regions to be dumped. */ | |
118 | struct region_t { | |
119 | vm_address_t address; | |
120 | vm_size_t size; | |
121 | vm_prot_t protection; | |
122 | vm_prot_t max_protection; | |
123 | ||
124 | struct region_t *next; | |
125 | }; | |
126 | ||
127 | /* Head and tail of the list of regions to be dumped. */ | |
128 | struct region_t *region_list_head = 0; | |
129 | struct region_t *region_list_tail = 0; | |
130 | ||
131 | /* Pointer to array of load commands. */ | |
132 | struct load_command **lca; | |
133 | ||
134 | /* Number of load commands. */ | |
135 | int nlc; | |
136 | ||
137 | /* The highest VM address of segments loaded by the input file. | |
138 | Regions with addresses beyond this are assumed to be allocated | |
139 | dynamically and thus require dumping. */ | |
140 | vm_address_t infile_lc_highest_addr = 0; | |
141 | ||
142 | /* The lowest file offset used by the all sections in the __TEXT | |
143 | segments. This leaves room at the beginning of the file to store | |
144 | the Mach-O header. Check this value against header size to ensure | |
145 | the added load commands for the new __DATA segments did not | |
146 | overwrite any of the sections in the __TEXT segment. */ | |
147 | unsigned long text_seg_lowest_offset = 0x10000000; | |
148 | ||
149 | /* Mach header. */ | |
150 | struct mach_header mh; | |
151 | ||
152 | /* Offset at which the next load command should be written. */ | |
153 | unsigned long curr_header_offset = sizeof (struct mach_header); | |
154 | ||
155 | /* Current adjustment that needs to be made to offset values because | |
156 | of additional data segments. */ | |
157 | unsigned long delta = 0; | |
158 | ||
159 | int infd, outfd; | |
160 | ||
161 | int in_dumped_exec = 0; | |
162 | ||
163 | malloc_zone_t *emacs_zone; | |
164 | ||
6b61353c KH |
165 | /* file offset of input file's data segment */ |
166 | off_t data_segment_old_fileoff; | |
167 | ||
168 | struct segment_command *data_segment_scp; | |
169 | ||
e0f712ba AC |
170 | /* Read n bytes from infd into memory starting at address dest. |
171 | Return true if successful, false otherwise. */ | |
172 | static int | |
173 | unexec_read (void *dest, size_t n) | |
174 | { | |
175 | return n == read (infd, dest, n); | |
176 | } | |
177 | ||
178 | /* Write n bytes from memory starting at address src to outfd starting | |
179 | at offset dest. Return true if successful, false otherwise. */ | |
180 | static int | |
181 | unexec_write (off_t dest, const void *src, size_t count) | |
182 | { | |
183 | if (lseek (outfd, dest, SEEK_SET) != dest) | |
184 | return 0; | |
185 | ||
186 | return write (outfd, src, count) == count; | |
187 | } | |
188 | ||
189 | /* Copy n bytes from starting offset src in infd to starting offset | |
190 | dest in outfd. Return true if successful, false otherwise. */ | |
191 | static int | |
192 | unexec_copy (off_t dest, off_t src, ssize_t count) | |
193 | { | |
194 | ssize_t bytes_read; | |
6b61353c | 195 | ssize_t bytes_to_read; |
e0f712ba AC |
196 | |
197 | char buf[UNEXEC_COPY_BUFSZ]; | |
198 | ||
199 | if (lseek (infd, src, SEEK_SET) != src) | |
200 | return 0; | |
201 | ||
202 | if (lseek (outfd, dest, SEEK_SET) != dest) | |
203 | return 0; | |
204 | ||
205 | while (count > 0) | |
206 | { | |
6b61353c KH |
207 | bytes_to_read = count > UNEXEC_COPY_BUFSZ ? UNEXEC_COPY_BUFSZ : count; |
208 | bytes_read = read (infd, buf, bytes_to_read); | |
e0f712ba AC |
209 | if (bytes_read <= 0) |
210 | return 0; | |
211 | if (write (outfd, buf, bytes_read) != bytes_read) | |
212 | return 0; | |
213 | count -= bytes_read; | |
214 | } | |
215 | ||
216 | return 1; | |
217 | } | |
218 | ||
219 | /* Debugging and informational messages routines. */ | |
220 | ||
221 | static void | |
222 | unexec_error (char *format, ...) | |
223 | { | |
224 | va_list ap; | |
225 | ||
226 | va_start (ap, format); | |
227 | fprintf (stderr, "unexec: "); | |
228 | vfprintf (stderr, format, ap); | |
229 | fprintf (stderr, "\n"); | |
230 | va_end (ap); | |
231 | exit (1); | |
232 | } | |
233 | ||
234 | static void | |
235 | print_prot (vm_prot_t prot) | |
236 | { | |
237 | if (prot == VM_PROT_NONE) | |
238 | printf ("none"); | |
239 | else | |
240 | { | |
241 | putchar (prot & VM_PROT_READ ? 'r' : ' '); | |
242 | putchar (prot & VM_PROT_WRITE ? 'w' : ' '); | |
243 | putchar (prot & VM_PROT_EXECUTE ? 'x' : ' '); | |
244 | putchar (' '); | |
245 | } | |
246 | } | |
247 | ||
248 | static void | |
249 | print_region (vm_address_t address, vm_size_t size, vm_prot_t prot, | |
250 | vm_prot_t max_prot) | |
251 | { | |
252 | printf ("%#10x %#8x ", address, size); | |
253 | print_prot (prot); | |
254 | putchar (' '); | |
255 | print_prot (max_prot); | |
256 | putchar ('\n'); | |
257 | } | |
258 | ||
259 | static void | |
260 | print_region_list () | |
261 | { | |
262 | struct region_t *r; | |
263 | ||
264 | printf (" address size prot maxp\n"); | |
265 | ||
266 | for (r = region_list_head; r; r = r->next) | |
267 | print_region (r->address, r->size, r->protection, r->max_protection); | |
268 | } | |
269 | ||
270 | void | |
271 | print_regions () | |
272 | { | |
273 | task_t target_task = mach_task_self (); | |
274 | vm_address_t address = (vm_address_t) 0; | |
275 | vm_size_t size; | |
276 | struct vm_region_basic_info info; | |
277 | mach_msg_type_number_t info_count = VM_REGION_BASIC_INFO_COUNT; | |
278 | mach_port_t object_name; | |
279 | ||
280 | printf (" address size prot maxp\n"); | |
281 | ||
282 | while (vm_region (target_task, &address, &size, VM_REGION_BASIC_INFO, | |
283 | (vm_region_info_t) &info, &info_count, &object_name) | |
284 | == KERN_SUCCESS && info_count == VM_REGION_BASIC_INFO_COUNT) | |
285 | { | |
286 | print_region (address, size, info.protection, info.max_protection); | |
287 | ||
288 | if (object_name != MACH_PORT_NULL) | |
289 | mach_port_deallocate (target_task, object_name); | |
177c0ea7 | 290 | |
e0f712ba AC |
291 | address += size; |
292 | } | |
293 | } | |
294 | ||
295 | /* Build the list of regions that need to be dumped. Regions with | |
296 | addresses above VM_DATA_TOP are omitted. Adjacent regions with | |
297 | identical protection are merged. Note that non-writable regions | |
298 | cannot be omitted because they some regions created at run time are | |
299 | read-only. */ | |
300 | static void | |
301 | build_region_list () | |
302 | { | |
303 | task_t target_task = mach_task_self (); | |
304 | vm_address_t address = (vm_address_t) 0; | |
305 | vm_size_t size; | |
306 | struct vm_region_basic_info info; | |
307 | mach_msg_type_number_t info_count = VM_REGION_BASIC_INFO_COUNT; | |
308 | mach_port_t object_name; | |
309 | struct region_t *r; | |
310 | ||
311 | #if VERBOSE | |
312 | printf ("--- List of All Regions ---\n"); | |
313 | printf (" address size prot maxp\n"); | |
314 | #endif | |
315 | ||
316 | while (vm_region (target_task, &address, &size, VM_REGION_BASIC_INFO, | |
317 | (vm_region_info_t) &info, &info_count, &object_name) | |
318 | == KERN_SUCCESS && info_count == VM_REGION_BASIC_INFO_COUNT) | |
319 | { | |
320 | /* Done when we reach addresses of shared libraries, which are | |
321 | loaded in high memory. */ | |
322 | if (address >= VM_DATA_TOP) | |
323 | break; | |
324 | ||
325 | #if VERBOSE | |
326 | print_region (address, size, info.protection, info.max_protection); | |
327 | #endif | |
328 | ||
329 | /* If a region immediately follows the previous one (the one | |
330 | most recently added to the list) and has identical | |
331 | protection, merge it with the latter. Otherwise create a | |
332 | new list element for it. */ | |
333 | if (region_list_tail | |
334 | && info.protection == region_list_tail->protection | |
335 | && info.max_protection == region_list_tail->max_protection | |
336 | && region_list_tail->address + region_list_tail->size == address) | |
337 | { | |
338 | region_list_tail->size += size; | |
339 | } | |
340 | else | |
341 | { | |
342 | r = (struct region_t *) malloc (sizeof (struct region_t)); | |
177c0ea7 | 343 | |
e0f712ba AC |
344 | if (!r) |
345 | unexec_error ("cannot allocate region structure"); | |
177c0ea7 | 346 | |
e0f712ba AC |
347 | r->address = address; |
348 | r->size = size; | |
349 | r->protection = info.protection; | |
350 | r->max_protection = info.max_protection; | |
177c0ea7 | 351 | |
e0f712ba AC |
352 | r->next = 0; |
353 | if (region_list_head == 0) | |
354 | { | |
355 | region_list_head = r; | |
356 | region_list_tail = r; | |
357 | } | |
358 | else | |
359 | { | |
360 | region_list_tail->next = r; | |
361 | region_list_tail = r; | |
362 | } | |
177c0ea7 | 363 | |
e0f712ba AC |
364 | /* Deallocate (unused) object name returned by |
365 | vm_region. */ | |
366 | if (object_name != MACH_PORT_NULL) | |
367 | mach_port_deallocate (target_task, object_name); | |
368 | } | |
177c0ea7 | 369 | |
e0f712ba AC |
370 | address += size; |
371 | } | |
372 | ||
373 | printf ("--- List of Regions to be Dumped ---\n"); | |
374 | print_region_list (); | |
375 | } | |
376 | ||
377 | ||
1dd7ccf2 | 378 | #define MAX_UNEXEC_REGIONS 200 |
e0f712ba AC |
379 | |
380 | int num_unexec_regions; | |
381 | vm_range_t unexec_regions[MAX_UNEXEC_REGIONS]; | |
382 | ||
383 | static void | |
384 | unexec_regions_recorder (task_t task, void *rr, unsigned type, | |
385 | vm_range_t *ranges, unsigned num) | |
386 | { | |
387 | while (num && num_unexec_regions < MAX_UNEXEC_REGIONS) | |
388 | { | |
389 | unexec_regions[num_unexec_regions++] = *ranges; | |
390 | printf ("%#8x (sz: %#8x)\n", ranges->address, ranges->size); | |
391 | ranges++; num--; | |
392 | } | |
393 | if (num_unexec_regions == MAX_UNEXEC_REGIONS) | |
394 | fprintf (stderr, "malloc_freezedry_recorder: too many regions\n"); | |
395 | } | |
396 | ||
397 | static kern_return_t | |
398 | unexec_reader (task_t task, vm_address_t address, vm_size_t size, void **ptr) | |
399 | { | |
400 | *ptr = (void *) address; | |
401 | return KERN_SUCCESS; | |
402 | } | |
403 | ||
404 | void | |
405 | find_emacs_zone_regions () | |
406 | { | |
407 | num_unexec_regions = 0; | |
408 | ||
409 | emacs_zone->introspect->enumerator (mach_task_self(), 0, | |
410 | MALLOC_PTR_REGION_RANGE_TYPE | |
411 | | MALLOC_ADMIN_REGION_RANGE_TYPE, | |
412 | (vm_address_t) emacs_zone, | |
413 | unexec_reader, | |
414 | unexec_regions_recorder); | |
415 | } | |
416 | ||
1dd7ccf2 AC |
417 | static int |
418 | unexec_regions_sort_compare (const void *a, const void *b) | |
419 | { | |
420 | vm_address_t aa = ((vm_range_t *) a)->address; | |
421 | vm_address_t bb = ((vm_range_t *) b)->address; | |
422 | ||
423 | if (aa < bb) | |
424 | return -1; | |
425 | else if (aa > bb) | |
426 | return 1; | |
427 | else | |
428 | return 0; | |
429 | } | |
430 | ||
431 | static void | |
432 | unexec_regions_merge () | |
433 | { | |
434 | int i, n; | |
435 | vm_range_t r; | |
436 | ||
437 | qsort (unexec_regions, num_unexec_regions, sizeof (unexec_regions[0]), | |
438 | &unexec_regions_sort_compare); | |
439 | n = 0; | |
440 | r = unexec_regions[0]; | |
441 | for (i = 1; i < num_unexec_regions; i++) | |
442 | { | |
443 | if (r.address + r.size == unexec_regions[i].address) | |
444 | { | |
445 | r.size += unexec_regions[i].size; | |
446 | } | |
447 | else | |
448 | { | |
449 | unexec_regions[n++] = r; | |
450 | r = unexec_regions[i]; | |
451 | } | |
452 | } | |
453 | unexec_regions[n++] = r; | |
454 | num_unexec_regions = n; | |
455 | } | |
456 | ||
e0f712ba AC |
457 | |
458 | /* More informational messages routines. */ | |
459 | ||
460 | static void | |
461 | print_load_command_name (int lc) | |
462 | { | |
463 | switch (lc) | |
464 | { | |
465 | case LC_SEGMENT: | |
466 | printf ("LC_SEGMENT "); | |
467 | break; | |
468 | case LC_LOAD_DYLINKER: | |
469 | printf ("LC_LOAD_DYLINKER "); | |
470 | break; | |
471 | case LC_LOAD_DYLIB: | |
472 | printf ("LC_LOAD_DYLIB "); | |
473 | break; | |
474 | case LC_SYMTAB: | |
475 | printf ("LC_SYMTAB "); | |
476 | break; | |
477 | case LC_DYSYMTAB: | |
478 | printf ("LC_DYSYMTAB "); | |
479 | break; | |
480 | case LC_UNIXTHREAD: | |
481 | printf ("LC_UNIXTHREAD "); | |
482 | break; | |
483 | case LC_PREBOUND_DYLIB: | |
484 | printf ("LC_PREBOUND_DYLIB"); | |
485 | break; | |
486 | case LC_TWOLEVEL_HINTS: | |
487 | printf ("LC_TWOLEVEL_HINTS"); | |
488 | break; | |
489 | default: | |
490 | printf ("unknown "); | |
491 | } | |
492 | } | |
493 | ||
494 | static void | |
495 | print_load_command (struct load_command *lc) | |
496 | { | |
497 | print_load_command_name (lc->cmd); | |
498 | printf ("%8d", lc->cmdsize); | |
499 | ||
500 | if (lc->cmd == LC_SEGMENT) | |
501 | { | |
502 | struct segment_command *scp; | |
503 | struct section *sectp; | |
504 | int j; | |
505 | ||
506 | scp = (struct segment_command *) lc; | |
507 | printf (" %-16.16s %#10x %#8x\n", | |
508 | scp->segname, scp->vmaddr, scp->vmsize); | |
509 | ||
510 | sectp = (struct section *) (scp + 1); | |
511 | for (j = 0; j < scp->nsects; j++) | |
512 | { | |
513 | printf (" %-16.16s %#10x %#8x\n", | |
514 | sectp->sectname, sectp->addr, sectp->size); | |
515 | sectp++; | |
516 | } | |
517 | } | |
518 | else | |
519 | printf ("\n"); | |
520 | } | |
521 | ||
522 | /* Read header and load commands from input file. Store the latter in | |
523 | the global array lca. Store the total number of load commands in | |
524 | global variable nlc. */ | |
525 | static void | |
526 | read_load_commands () | |
527 | { | |
528 | int n, i, j; | |
529 | ||
530 | if (!unexec_read (&mh, sizeof (struct mach_header))) | |
531 | unexec_error ("cannot read mach-o header"); | |
532 | ||
533 | if (mh.magic != MH_MAGIC) | |
534 | unexec_error ("input file not in Mach-O format"); | |
535 | ||
536 | if (mh.filetype != MH_EXECUTE) | |
537 | unexec_error ("input Mach-O file is not an executable object file"); | |
538 | ||
539 | #if VERBOSE | |
540 | printf ("--- Header Information ---\n"); | |
541 | printf ("Magic = 0x%08x\n", mh.magic); | |
542 | printf ("CPUType = %d\n", mh.cputype); | |
543 | printf ("CPUSubType = %d\n", mh.cpusubtype); | |
544 | printf ("FileType = 0x%x\n", mh.filetype); | |
545 | printf ("NCmds = %d\n", mh.ncmds); | |
546 | printf ("SizeOfCmds = %d\n", mh.sizeofcmds); | |
547 | printf ("Flags = 0x%08x\n", mh.flags); | |
548 | #endif | |
549 | ||
550 | nlc = mh.ncmds; | |
551 | lca = (struct load_command **) malloc (nlc * sizeof (struct load_command *)); | |
177c0ea7 | 552 | |
e0f712ba AC |
553 | for (i = 0; i < nlc; i++) |
554 | { | |
555 | struct load_command lc; | |
556 | /* Load commands are variable-size: so read the command type and | |
557 | size first and then read the rest. */ | |
558 | if (!unexec_read (&lc, sizeof (struct load_command))) | |
559 | unexec_error ("cannot read load command"); | |
560 | lca[i] = (struct load_command *) malloc (lc.cmdsize); | |
561 | memcpy (lca[i], &lc, sizeof (struct load_command)); | |
562 | if (!unexec_read (lca[i] + 1, lc.cmdsize - sizeof (struct load_command))) | |
563 | unexec_error ("cannot read content of load command"); | |
564 | if (lc.cmd == LC_SEGMENT) | |
565 | { | |
566 | struct segment_command *scp = (struct segment_command *) lca[i]; | |
177c0ea7 | 567 | |
e0f712ba AC |
568 | if (scp->vmaddr + scp->vmsize > infile_lc_highest_addr) |
569 | infile_lc_highest_addr = scp->vmaddr + scp->vmsize; | |
570 | ||
571 | if (strncmp (scp->segname, SEG_TEXT, 16) == 0) | |
572 | { | |
573 | struct section *sectp = (struct section *) (scp + 1); | |
574 | int j; | |
575 | ||
576 | for (j = 0; j < scp->nsects; j++) | |
577 | if (sectp->offset < text_seg_lowest_offset) | |
578 | text_seg_lowest_offset = sectp->offset; | |
579 | } | |
580 | } | |
581 | } | |
582 | ||
583 | printf ("Highest address of load commands in input file: %#8x\n", | |
584 | infile_lc_highest_addr); | |
585 | ||
586 | printf ("Lowest offset of all sections in __TEXT segment: %#8x\n", | |
587 | text_seg_lowest_offset); | |
588 | ||
589 | printf ("--- List of Load Commands in Input File ---\n"); | |
590 | printf ("# cmd cmdsize name address size\n"); | |
591 | ||
592 | for (i = 0; i < nlc; i++) | |
593 | { | |
594 | printf ("%1d ", i); | |
595 | print_load_command (lca[i]); | |
596 | } | |
597 | } | |
598 | ||
599 | /* Copy a LC_SEGMENT load command other than the __DATA segment from | |
600 | the input file to the output file, adjusting the file offset of the | |
601 | segment and the file offsets of sections contained in it. */ | |
602 | static void | |
603 | copy_segment (struct load_command *lc) | |
604 | { | |
605 | struct segment_command *scp = (struct segment_command *) lc; | |
606 | unsigned long old_fileoff = scp->fileoff; | |
607 | struct section *sectp; | |
608 | int j; | |
609 | ||
610 | scp->fileoff += delta; | |
611 | ||
612 | sectp = (struct section *) (scp + 1); | |
613 | for (j = 0; j < scp->nsects; j++) | |
614 | { | |
615 | sectp->offset += delta; | |
616 | sectp++; | |
617 | } | |
618 | ||
619 | printf ("Writing segment %-16.16s at %#8x - %#8x (sz: %#8x)\n", | |
620 | scp->segname, scp->fileoff, scp->fileoff + scp->filesize, | |
621 | scp->filesize); | |
622 | ||
623 | if (!unexec_copy (scp->fileoff, old_fileoff, scp->filesize)) | |
624 | unexec_error ("cannot copy segment from input to output file"); | |
625 | if (!unexec_write (curr_header_offset, lc, lc->cmdsize)) | |
626 | unexec_error ("cannot write load command to header"); | |
627 | ||
628 | curr_header_offset += lc->cmdsize; | |
629 | } | |
630 | ||
631 | /* Copy a LC_SEGMENT load command for the __DATA segment in the input | |
632 | file to the output file. We assume that only one such segment load | |
633 | command exists in the input file and it contains the sections | |
634 | __data, __bss, __common, __la_symbol_ptr, __nl_symbol_ptr, and | |
635 | __dyld. The first three of these should be dumped from memory and | |
636 | the rest should be copied from the input file. Note that the | |
637 | sections __bss and __common contain no data in the input file | |
638 | because their flag fields have the value S_ZEROFILL. Dumping these | |
639 | from memory makes it necessary to adjust file offset fields in | |
640 | subsequently dumped load commands. Then, create new __DATA segment | |
641 | load commands for regions on the region list other than the one | |
642 | corresponding to the __DATA segment in the input file. */ | |
643 | static void | |
644 | copy_data_segment (struct load_command *lc) | |
645 | { | |
646 | struct segment_command *scp = (struct segment_command *) lc; | |
647 | struct section *sectp; | |
648 | int j; | |
649 | unsigned long header_offset, file_offset, old_file_offset; | |
650 | struct region_t *r; | |
651 | ||
652 | printf ("Writing segment %-16.16s at %#8x - %#8x (sz: %#8x)\n", | |
653 | scp->segname, scp->fileoff, scp->fileoff + scp->filesize, | |
654 | scp->filesize); | |
655 | ||
656 | if (delta != 0) | |
657 | unexec_error ("cannot handle multiple DATA segments in input file"); | |
658 | ||
659 | /* Offsets in the output file for writing the next section structure | |
660 | and segment data block, respectively. */ | |
661 | header_offset = curr_header_offset + sizeof (struct segment_command); | |
662 | ||
663 | sectp = (struct section *) (scp + 1); | |
664 | for (j = 0; j < scp->nsects; j++) | |
665 | { | |
666 | old_file_offset = sectp->offset; | |
667 | sectp->offset = sectp->addr - scp->vmaddr + scp->fileoff; | |
668 | /* The __data section is dumped from memory. The __bss and | |
669 | __common sections are also dumped from memory but their flag | |
670 | fields require changing (from S_ZEROFILL to S_REGULAR). The | |
671 | other three kinds of sections are just copied from the input | |
672 | file. */ | |
673 | if (strncmp (sectp->sectname, SECT_DATA, 16) == 0) | |
674 | { | |
675 | if (!unexec_write (sectp->offset, (void *) sectp->addr, sectp->size)) | |
676 | unexec_error ("cannot write section %s", SECT_DATA); | |
677 | if (!unexec_write (header_offset, sectp, sizeof (struct section))) | |
678 | unexec_error ("cannot write section %s's header", SECT_DATA); | |
679 | } | |
680 | else if (strncmp (sectp->sectname, SECT_BSS, 16) == 0 | |
681 | || strncmp (sectp->sectname, SECT_COMMON, 16) == 0) | |
682 | { | |
683 | sectp->flags = S_REGULAR; | |
684 | if (!unexec_write (sectp->offset, (void *) sectp->addr, sectp->size)) | |
685 | unexec_error ("cannot write section %s", SECT_DATA); | |
686 | if (!unexec_write (header_offset, sectp, sizeof (struct section))) | |
687 | unexec_error ("cannot write section %s's header", SECT_DATA); | |
688 | } | |
689 | else if (strncmp (sectp->sectname, "__la_symbol_ptr", 16) == 0 | |
690 | || strncmp (sectp->sectname, "__nl_symbol_ptr", 16) == 0 | |
691 | || strncmp (sectp->sectname, "__dyld", 16) == 0 | |
7290a344 AC |
692 | || strncmp (sectp->sectname, "__const", 16) == 0 |
693 | || strncmp (sectp->sectname, "__cfstring", 16) == 0) | |
e0f712ba AC |
694 | { |
695 | if (!unexec_copy (sectp->offset, old_file_offset, sectp->size)) | |
696 | unexec_error ("cannot copy section %s", sectp->sectname); | |
697 | if (!unexec_write (header_offset, sectp, sizeof (struct section))) | |
698 | unexec_error ("cannot write section %s's header", sectp->sectname); | |
699 | } | |
700 | else | |
701 | unexec_error ("unrecognized section name in __DATA segment"); | |
177c0ea7 | 702 | |
e0f712ba AC |
703 | printf (" section %-16.16s at %#8x - %#8x (sz: %#8x)\n", |
704 | sectp->sectname, sectp->offset, sectp->offset + sectp->size, | |
705 | sectp->size); | |
706 | ||
707 | header_offset += sizeof (struct section); | |
708 | sectp++; | |
709 | } | |
710 | ||
711 | /* The new filesize of the segment is set to its vmsize because data | |
712 | blocks for segments must start at region boundaries. Note that | |
713 | this may leave unused locations at the end of the segment data | |
714 | block because the total of the sizes of all sections in the | |
715 | segment is generally smaller than vmsize. */ | |
716 | delta = scp->vmsize - scp->filesize; | |
717 | scp->filesize = scp->vmsize; | |
718 | if (!unexec_write (curr_header_offset, scp, sizeof (struct segment_command))) | |
719 | unexec_error ("cannot write header of __DATA segment"); | |
720 | curr_header_offset += lc->cmdsize; | |
721 | ||
722 | /* Create new __DATA segment load commands for regions on the region | |
723 | list that do not corresponding to any segment load commands in | |
724 | the input file. | |
725 | */ | |
726 | file_offset = scp->fileoff + scp->filesize; | |
727 | for (j = 0; j < num_unexec_regions; j++) | |
728 | { | |
729 | struct segment_command sc; | |
177c0ea7 | 730 | |
e0f712ba AC |
731 | sc.cmd = LC_SEGMENT; |
732 | sc.cmdsize = sizeof (struct segment_command); | |
733 | strncpy (sc.segname, SEG_DATA, 16); | |
734 | sc.vmaddr = unexec_regions[j].address; | |
735 | sc.vmsize = unexec_regions[j].size; | |
736 | sc.fileoff = file_offset; | |
737 | sc.filesize = unexec_regions[j].size; | |
738 | sc.maxprot = VM_PROT_READ | VM_PROT_WRITE; | |
739 | sc.initprot = VM_PROT_READ | VM_PROT_WRITE; | |
740 | sc.nsects = 0; | |
741 | sc.flags = 0; | |
177c0ea7 | 742 | |
e0f712ba AC |
743 | printf ("Writing segment %-16.16s at %#8x - %#8x (sz: %#8x)\n", |
744 | sc.segname, sc.fileoff, sc.fileoff + sc.filesize, | |
745 | sc.filesize); | |
746 | ||
747 | if (!unexec_write (sc.fileoff, (void *) sc.vmaddr, sc.vmsize)) | |
748 | unexec_error ("cannot write new __DATA segment"); | |
749 | delta += sc.filesize; | |
750 | file_offset += sc.filesize; | |
177c0ea7 | 751 | |
e0f712ba AC |
752 | if (!unexec_write (curr_header_offset, &sc, sc.cmdsize)) |
753 | unexec_error ("cannot write new __DATA segment's header"); | |
754 | curr_header_offset += sc.cmdsize; | |
755 | mh.ncmds++; | |
756 | } | |
757 | } | |
758 | ||
759 | /* Copy a LC_SYMTAB load command from the input file to the output | |
760 | file, adjusting the file offset fields. */ | |
761 | static void | |
762 | copy_symtab (struct load_command *lc) | |
763 | { | |
764 | struct symtab_command *stp = (struct symtab_command *) lc; | |
765 | ||
766 | stp->symoff += delta; | |
767 | stp->stroff += delta; | |
768 | ||
769 | printf ("Writing LC_SYMTAB command\n"); | |
770 | ||
771 | if (!unexec_write (curr_header_offset, lc, lc->cmdsize)) | |
772 | unexec_error ("cannot write symtab command to header"); | |
773 | ||
774 | curr_header_offset += lc->cmdsize; | |
775 | } | |
776 | ||
6b61353c KH |
777 | /* Fix up relocation entries. */ |
778 | static void | |
779 | unrelocate (const char *name, off_t reloff, int nrel) | |
780 | { | |
781 | int i, unreloc_count; | |
782 | struct relocation_info reloc_info; | |
783 | struct scattered_relocation_info *sc_reloc_info | |
784 | = (struct scattered_relocation_info *) &reloc_info; | |
785 | ||
786 | for (unreloc_count = 0, i = 0; i < nrel; i++) | |
787 | { | |
788 | if (lseek (infd, reloff, L_SET) != reloff) | |
789 | unexec_error ("unrelocate: %s:%d cannot seek to reloc_info", name, i); | |
790 | if (!unexec_read (&reloc_info, sizeof (reloc_info))) | |
791 | unexec_error ("unrelocate: %s:%d cannot read reloc_info", name, i); | |
792 | reloff += sizeof (reloc_info); | |
793 | ||
794 | if (sc_reloc_info->r_scattered == 0) | |
795 | switch (reloc_info.r_type) | |
796 | { | |
797 | case GENERIC_RELOC_VANILLA: | |
798 | if (reloc_info.r_address >= data_segment_scp->vmaddr | |
799 | && reloc_info.r_address < (data_segment_scp->vmaddr | |
800 | + data_segment_scp->vmsize)) | |
801 | { | |
802 | off_t src_off = data_segment_old_fileoff | |
803 | + reloc_info.r_address - data_segment_scp->vmaddr; | |
804 | off_t dst_off = data_segment_scp->fileoff | |
805 | + reloc_info.r_address - data_segment_scp->vmaddr; | |
806 | ||
807 | if (!unexec_copy (dst_off, src_off, 1 << reloc_info.r_length)) | |
808 | unexec_error ("unrelocate: %s:%d cannot copy original value", | |
809 | name, i); | |
810 | unreloc_count++; | |
811 | } | |
812 | break; | |
813 | default: | |
814 | unexec_error ("unrelocate: %s:%d cannot handle type = %d", | |
815 | name, i, reloc_info.r_type); | |
816 | } | |
817 | else | |
818 | switch (sc_reloc_info->r_type) | |
819 | { | |
820 | #if defined (__ppc__) | |
821 | case PPC_RELOC_PB_LA_PTR: | |
822 | /* nothing to do for prebound lazy pointer */ | |
823 | break; | |
824 | #endif | |
825 | default: | |
826 | unexec_error ("unrelocate: %s:%d cannot handle scattered type = %d", | |
827 | name, i, sc_reloc_info->r_type); | |
828 | } | |
829 | } | |
830 | ||
831 | if (nrel > 0) | |
832 | printf ("Fixed up %d/%d %s relocation entries in data segment.\n", | |
833 | unreloc_count, nrel, name); | |
834 | } | |
835 | ||
e0f712ba AC |
836 | /* Copy a LC_DYSYMTAB load command from the input file to the output |
837 | file, adjusting the file offset fields. */ | |
838 | static void | |
839 | copy_dysymtab (struct load_command *lc) | |
840 | { | |
841 | struct dysymtab_command *dstp = (struct dysymtab_command *) lc; | |
842 | ||
6b61353c KH |
843 | unrelocate ("local", dstp->locreloff, dstp->nlocrel); |
844 | unrelocate ("external", dstp->extreloff, dstp->nextrel); | |
e0f712ba AC |
845 | |
846 | if (dstp->nextrel > 0) { | |
847 | dstp->extreloff += delta; | |
848 | } | |
849 | ||
850 | if (dstp->nlocrel > 0) { | |
851 | dstp->locreloff += delta; | |
852 | } | |
853 | ||
854 | if (dstp->nindirectsyms > 0) | |
855 | dstp->indirectsymoff += delta; | |
856 | ||
857 | printf ("Writing LC_DYSYMTAB command\n"); | |
858 | ||
859 | if (!unexec_write (curr_header_offset, lc, lc->cmdsize)) | |
860 | unexec_error ("cannot write symtab command to header"); | |
861 | ||
862 | curr_header_offset += lc->cmdsize; | |
863 | } | |
864 | ||
40e6ff95 ST |
865 | /* Copy a LC_TWOLEVEL_HINTS load command from the input file to the output |
866 | file, adjusting the file offset fields. */ | |
867 | static void | |
868 | copy_twolevelhints (struct load_command *lc) | |
869 | { | |
870 | struct twolevel_hints_command *tlhp = (struct twolevel_hints_command *) lc; | |
871 | ||
872 | if (tlhp->nhints > 0) { | |
873 | tlhp->offset += delta; | |
874 | } | |
875 | ||
876 | printf ("Writing LC_TWOLEVEL_HINTS command\n"); | |
877 | ||
878 | if (!unexec_write (curr_header_offset, lc, lc->cmdsize)) | |
879 | unexec_error ("cannot write two level hint command to header"); | |
880 | ||
881 | curr_header_offset += lc->cmdsize; | |
882 | } | |
883 | ||
e0f712ba AC |
884 | /* Copy other kinds of load commands from the input file to the output |
885 | file, ones that do not require adjustments of file offsets. */ | |
886 | static void | |
887 | copy_other (struct load_command *lc) | |
888 | { | |
889 | printf ("Writing "); | |
890 | print_load_command_name (lc->cmd); | |
891 | printf (" command\n"); | |
892 | ||
893 | if (!unexec_write (curr_header_offset, lc, lc->cmdsize)) | |
894 | unexec_error ("cannot write symtab command to header"); | |
895 | ||
896 | curr_header_offset += lc->cmdsize; | |
897 | } | |
898 | ||
899 | /* Loop through all load commands and dump them. Then write the Mach | |
900 | header. */ | |
901 | static void | |
902 | dump_it () | |
903 | { | |
904 | int i; | |
905 | ||
906 | printf ("--- Load Commands written to Output File ---\n"); | |
907 | ||
908 | for (i = 0; i < nlc; i++) | |
909 | switch (lca[i]->cmd) | |
910 | { | |
911 | case LC_SEGMENT: | |
912 | { | |
913 | struct segment_command *scp = (struct segment_command *) lca[i]; | |
914 | if (strncmp (scp->segname, SEG_DATA, 16) == 0) | |
915 | { | |
6b61353c KH |
916 | /* save data segment file offset and segment_command for |
917 | unrelocate */ | |
918 | data_segment_old_fileoff = scp->fileoff; | |
919 | data_segment_scp = scp; | |
920 | ||
e0f712ba AC |
921 | copy_data_segment (lca[i]); |
922 | } | |
923 | else | |
924 | { | |
925 | copy_segment (lca[i]); | |
926 | } | |
927 | } | |
928 | break; | |
929 | case LC_SYMTAB: | |
930 | copy_symtab (lca[i]); | |
931 | break; | |
932 | case LC_DYSYMTAB: | |
933 | copy_dysymtab (lca[i]); | |
934 | break; | |
40e6ff95 ST |
935 | case LC_TWOLEVEL_HINTS: |
936 | copy_twolevelhints (lca[i]); | |
937 | break; | |
e0f712ba AC |
938 | default: |
939 | copy_other (lca[i]); | |
940 | break; | |
941 | } | |
942 | ||
943 | if (curr_header_offset > text_seg_lowest_offset) | |
944 | unexec_error ("not enough room for load commands for new __DATA segments"); | |
945 | ||
946 | printf ("%d unused bytes follow Mach-O header\n", | |
947 | text_seg_lowest_offset - curr_header_offset); | |
948 | ||
949 | mh.sizeofcmds = curr_header_offset - sizeof (struct mach_header); | |
950 | if (!unexec_write (0, &mh, sizeof (struct mach_header))) | |
951 | unexec_error ("cannot write final header contents"); | |
952 | } | |
953 | ||
954 | /* Take a snapshot of Emacs and make a Mach-O format executable file | |
955 | from it. The file names of the output and input files are outfile | |
956 | and infile, respectively. The three other parameters are | |
957 | ignored. */ | |
958 | void | |
959 | unexec (char *outfile, char *infile, void *start_data, void *start_bss, | |
960 | void *entry_address) | |
961 | { | |
962 | infd = open (infile, O_RDONLY, 0); | |
963 | if (infd < 0) | |
964 | { | |
965 | unexec_error ("cannot open input file `%s'", infile); | |
966 | } | |
177c0ea7 | 967 | |
e0f712ba AC |
968 | outfd = open (outfile, O_WRONLY | O_TRUNC | O_CREAT, 0755); |
969 | if (outfd < 0) | |
970 | { | |
971 | close (infd); | |
972 | unexec_error ("cannot open output file `%s'", outfile); | |
973 | } | |
974 | ||
975 | build_region_list (); | |
976 | read_load_commands (); | |
977 | ||
978 | find_emacs_zone_regions (); | |
1dd7ccf2 | 979 | unexec_regions_merge (); |
e0f712ba AC |
980 | |
981 | in_dumped_exec = 1; | |
982 | ||
983 | dump_it (); | |
984 | ||
985 | close (outfd); | |
986 | } | |
987 | ||
988 | ||
989 | void | |
990 | unexec_init_emacs_zone () | |
991 | { | |
992 | emacs_zone = malloc_create_zone (0, 0); | |
993 | malloc_set_zone_name (emacs_zone, "EmacsZone"); | |
994 | } | |
995 | ||
996 | int | |
997 | ptr_in_unexec_regions (void *ptr) | |
998 | { | |
999 | int i; | |
1000 | ||
1001 | for (i = 0; i < num_unexec_regions; i++) | |
1002 | if ((vm_address_t) ptr - unexec_regions[i].address | |
1003 | < unexec_regions[i].size) | |
1004 | return 1; | |
1005 | ||
1006 | return 0; | |
1007 | } | |
1008 | ||
1009 | void * | |
1010 | unexec_malloc (size_t size) | |
1011 | { | |
1012 | if (in_dumped_exec) | |
1013 | return malloc (size); | |
1014 | else | |
1015 | return malloc_zone_malloc (emacs_zone, size); | |
1016 | } | |
1017 | ||
1018 | void * | |
1019 | unexec_realloc (void *old_ptr, size_t new_size) | |
1020 | { | |
1021 | if (in_dumped_exec) | |
1022 | if (ptr_in_unexec_regions (old_ptr)) | |
1023 | { | |
1024 | char *p = malloc (new_size); | |
1025 | /* 2002-04-15 T. Ikegami <ikegami@adam.uprr.pr>. The original | |
1026 | code to get size failed to reallocate read_buffer | |
1027 | (lread.c). */ | |
82122254 | 1028 | int old_size = malloc_default_zone()->size (emacs_zone, old_ptr); |
e0f712ba AC |
1029 | int size = new_size > old_size ? old_size : new_size; |
1030 | ||
1031 | if (size) | |
1032 | memcpy (p, old_ptr, size); | |
1033 | return p; | |
1034 | } | |
1035 | else | |
1036 | return realloc (old_ptr, new_size); | |
1037 | else | |
1038 | return malloc_zone_realloc (emacs_zone, old_ptr, new_size); | |
1039 | } | |
1040 | ||
1041 | void | |
1042 | unexec_free (void *ptr) | |
1043 | { | |
1044 | if (in_dumped_exec) | |
1045 | { | |
1046 | if (!ptr_in_unexec_regions (ptr)) | |
1047 | free (ptr); | |
1048 | } | |
1049 | else | |
1050 | malloc_zone_free (emacs_zone, ptr); | |
1051 | } | |
6b61353c KH |
1052 | |
1053 | /* arch-tag: 1a784f7b-a184-4c4f-9544-da8619593d72 | |
1054 | (do not change this comment) */ |