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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> | |
043131c4 AC |
98 | #include <mach-o/reloc.h> |
99 | #if defined (__ppc__) | |
100 | #include <mach-o/ppc/reloc.h> | |
101 | #endif | |
f7f3a65f ST |
102 | #if defined (HAVE_MALLOC_MALLOC_H) |
103 | #include <malloc/malloc.h> | |
104 | #else | |
e0f712ba | 105 | #include <objc/malloc.h> |
f7f3a65f ST |
106 | #endif |
107 | ||
e0f712ba AC |
108 | |
109 | #define VERBOSE 1 | |
110 | ||
111 | /* Size of buffer used to copy data from the input file to the output | |
112 | file in function unexec_copy. */ | |
113 | #define UNEXEC_COPY_BUFSZ 1024 | |
114 | ||
115 | /* Regions with memory addresses above this value are assumed to be | |
116 | mapped to dynamically loaded libraries and will not be dumped. */ | |
117 | #define VM_DATA_TOP (20 * 1024 * 1024) | |
118 | ||
119 | /* Used by malloc_freezedry and malloc_jumpstart. */ | |
120 | int malloc_cookie; | |
121 | ||
122 | /* Type of an element on the list of regions to be dumped. */ | |
123 | struct region_t { | |
124 | vm_address_t address; | |
125 | vm_size_t size; | |
126 | vm_prot_t protection; | |
127 | vm_prot_t max_protection; | |
128 | ||
129 | struct region_t *next; | |
130 | }; | |
131 | ||
132 | /* Head and tail of the list of regions to be dumped. */ | |
133 | struct region_t *region_list_head = 0; | |
134 | struct region_t *region_list_tail = 0; | |
135 | ||
136 | /* Pointer to array of load commands. */ | |
137 | struct load_command **lca; | |
138 | ||
139 | /* Number of load commands. */ | |
140 | int nlc; | |
141 | ||
142 | /* The highest VM address of segments loaded by the input file. | |
143 | Regions with addresses beyond this are assumed to be allocated | |
144 | dynamically and thus require dumping. */ | |
145 | vm_address_t infile_lc_highest_addr = 0; | |
146 | ||
147 | /* The lowest file offset used by the all sections in the __TEXT | |
148 | segments. This leaves room at the beginning of the file to store | |
149 | the Mach-O header. Check this value against header size to ensure | |
150 | the added load commands for the new __DATA segments did not | |
151 | overwrite any of the sections in the __TEXT segment. */ | |
152 | unsigned long text_seg_lowest_offset = 0x10000000; | |
153 | ||
154 | /* Mach header. */ | |
155 | struct mach_header mh; | |
156 | ||
157 | /* Offset at which the next load command should be written. */ | |
158 | unsigned long curr_header_offset = sizeof (struct mach_header); | |
159 | ||
160 | /* Current adjustment that needs to be made to offset values because | |
161 | of additional data segments. */ | |
162 | unsigned long delta = 0; | |
163 | ||
164 | int infd, outfd; | |
165 | ||
166 | int in_dumped_exec = 0; | |
167 | ||
168 | malloc_zone_t *emacs_zone; | |
169 | ||
043131c4 AC |
170 | /* file offset of input file's data segment */ |
171 | off_t data_segment_old_fileoff; | |
172 | ||
173 | struct segment_command *data_segment_scp; | |
174 | ||
e0f712ba AC |
175 | /* Read n bytes from infd into memory starting at address dest. |
176 | Return true if successful, false otherwise. */ | |
177 | static int | |
178 | unexec_read (void *dest, size_t n) | |
179 | { | |
180 | return n == read (infd, dest, n); | |
181 | } | |
182 | ||
183 | /* Write n bytes from memory starting at address src to outfd starting | |
184 | at offset dest. Return true if successful, false otherwise. */ | |
185 | static int | |
186 | unexec_write (off_t dest, const void *src, size_t count) | |
187 | { | |
188 | if (lseek (outfd, dest, SEEK_SET) != dest) | |
189 | return 0; | |
190 | ||
191 | return write (outfd, src, count) == count; | |
192 | } | |
193 | ||
194 | /* Copy n bytes from starting offset src in infd to starting offset | |
195 | dest in outfd. Return true if successful, false otherwise. */ | |
196 | static int | |
197 | unexec_copy (off_t dest, off_t src, ssize_t count) | |
198 | { | |
199 | ssize_t bytes_read; | |
911c78b4 | 200 | ssize_t bytes_to_read; |
e0f712ba AC |
201 | |
202 | char buf[UNEXEC_COPY_BUFSZ]; | |
203 | ||
204 | if (lseek (infd, src, SEEK_SET) != src) | |
205 | return 0; | |
206 | ||
207 | if (lseek (outfd, dest, SEEK_SET) != dest) | |
208 | return 0; | |
209 | ||
210 | while (count > 0) | |
211 | { | |
911c78b4 ST |
212 | bytes_to_read = count > UNEXEC_COPY_BUFSZ ? UNEXEC_COPY_BUFSZ : count; |
213 | bytes_read = read (infd, buf, bytes_to_read); | |
e0f712ba AC |
214 | if (bytes_read <= 0) |
215 | return 0; | |
216 | if (write (outfd, buf, bytes_read) != bytes_read) | |
217 | return 0; | |
218 | count -= bytes_read; | |
219 | } | |
220 | ||
221 | return 1; | |
222 | } | |
223 | ||
224 | /* Debugging and informational messages routines. */ | |
225 | ||
226 | static void | |
227 | unexec_error (char *format, ...) | |
228 | { | |
229 | va_list ap; | |
230 | ||
231 | va_start (ap, format); | |
232 | fprintf (stderr, "unexec: "); | |
233 | vfprintf (stderr, format, ap); | |
234 | fprintf (stderr, "\n"); | |
235 | va_end (ap); | |
236 | exit (1); | |
237 | } | |
238 | ||
239 | static void | |
240 | print_prot (vm_prot_t prot) | |
241 | { | |
242 | if (prot == VM_PROT_NONE) | |
243 | printf ("none"); | |
244 | else | |
245 | { | |
246 | putchar (prot & VM_PROT_READ ? 'r' : ' '); | |
247 | putchar (prot & VM_PROT_WRITE ? 'w' : ' '); | |
248 | putchar (prot & VM_PROT_EXECUTE ? 'x' : ' '); | |
249 | putchar (' '); | |
250 | } | |
251 | } | |
252 | ||
253 | static void | |
254 | print_region (vm_address_t address, vm_size_t size, vm_prot_t prot, | |
255 | vm_prot_t max_prot) | |
256 | { | |
257 | printf ("%#10x %#8x ", address, size); | |
258 | print_prot (prot); | |
259 | putchar (' '); | |
260 | print_prot (max_prot); | |
261 | putchar ('\n'); | |
262 | } | |
263 | ||
264 | static void | |
265 | print_region_list () | |
266 | { | |
267 | struct region_t *r; | |
268 | ||
269 | printf (" address size prot maxp\n"); | |
270 | ||
271 | for (r = region_list_head; r; r = r->next) | |
272 | print_region (r->address, r->size, r->protection, r->max_protection); | |
273 | } | |
274 | ||
275 | void | |
276 | print_regions () | |
277 | { | |
278 | task_t target_task = mach_task_self (); | |
279 | vm_address_t address = (vm_address_t) 0; | |
280 | vm_size_t size; | |
281 | struct vm_region_basic_info info; | |
282 | mach_msg_type_number_t info_count = VM_REGION_BASIC_INFO_COUNT; | |
283 | mach_port_t object_name; | |
284 | ||
285 | printf (" address size prot maxp\n"); | |
286 | ||
287 | while (vm_region (target_task, &address, &size, VM_REGION_BASIC_INFO, | |
288 | (vm_region_info_t) &info, &info_count, &object_name) | |
289 | == KERN_SUCCESS && info_count == VM_REGION_BASIC_INFO_COUNT) | |
290 | { | |
291 | print_region (address, size, info.protection, info.max_protection); | |
292 | ||
293 | if (object_name != MACH_PORT_NULL) | |
294 | mach_port_deallocate (target_task, object_name); | |
177c0ea7 | 295 | |
e0f712ba AC |
296 | address += size; |
297 | } | |
298 | } | |
299 | ||
300 | /* Build the list of regions that need to be dumped. Regions with | |
301 | addresses above VM_DATA_TOP are omitted. Adjacent regions with | |
302 | identical protection are merged. Note that non-writable regions | |
303 | cannot be omitted because they some regions created at run time are | |
304 | read-only. */ | |
305 | static void | |
306 | build_region_list () | |
307 | { | |
308 | task_t target_task = mach_task_self (); | |
309 | vm_address_t address = (vm_address_t) 0; | |
310 | vm_size_t size; | |
311 | struct vm_region_basic_info info; | |
312 | mach_msg_type_number_t info_count = VM_REGION_BASIC_INFO_COUNT; | |
313 | mach_port_t object_name; | |
314 | struct region_t *r; | |
315 | ||
316 | #if VERBOSE | |
317 | printf ("--- List of All Regions ---\n"); | |
318 | printf (" address size prot maxp\n"); | |
319 | #endif | |
320 | ||
321 | while (vm_region (target_task, &address, &size, VM_REGION_BASIC_INFO, | |
322 | (vm_region_info_t) &info, &info_count, &object_name) | |
323 | == KERN_SUCCESS && info_count == VM_REGION_BASIC_INFO_COUNT) | |
324 | { | |
325 | /* Done when we reach addresses of shared libraries, which are | |
326 | loaded in high memory. */ | |
327 | if (address >= VM_DATA_TOP) | |
328 | break; | |
329 | ||
330 | #if VERBOSE | |
331 | print_region (address, size, info.protection, info.max_protection); | |
332 | #endif | |
333 | ||
334 | /* If a region immediately follows the previous one (the one | |
335 | most recently added to the list) and has identical | |
336 | protection, merge it with the latter. Otherwise create a | |
337 | new list element for it. */ | |
338 | if (region_list_tail | |
339 | && info.protection == region_list_tail->protection | |
340 | && info.max_protection == region_list_tail->max_protection | |
341 | && region_list_tail->address + region_list_tail->size == address) | |
342 | { | |
343 | region_list_tail->size += size; | |
344 | } | |
345 | else | |
346 | { | |
347 | r = (struct region_t *) malloc (sizeof (struct region_t)); | |
177c0ea7 | 348 | |
e0f712ba AC |
349 | if (!r) |
350 | unexec_error ("cannot allocate region structure"); | |
177c0ea7 | 351 | |
e0f712ba AC |
352 | r->address = address; |
353 | r->size = size; | |
354 | r->protection = info.protection; | |
355 | r->max_protection = info.max_protection; | |
177c0ea7 | 356 | |
e0f712ba AC |
357 | r->next = 0; |
358 | if (region_list_head == 0) | |
359 | { | |
360 | region_list_head = r; | |
361 | region_list_tail = r; | |
362 | } | |
363 | else | |
364 | { | |
365 | region_list_tail->next = r; | |
366 | region_list_tail = r; | |
367 | } | |
177c0ea7 | 368 | |
e0f712ba AC |
369 | /* Deallocate (unused) object name returned by |
370 | vm_region. */ | |
371 | if (object_name != MACH_PORT_NULL) | |
372 | mach_port_deallocate (target_task, object_name); | |
373 | } | |
177c0ea7 | 374 | |
e0f712ba AC |
375 | address += size; |
376 | } | |
377 | ||
378 | printf ("--- List of Regions to be Dumped ---\n"); | |
379 | print_region_list (); | |
380 | } | |
381 | ||
382 | ||
1dd7ccf2 | 383 | #define MAX_UNEXEC_REGIONS 200 |
e0f712ba AC |
384 | |
385 | int num_unexec_regions; | |
386 | vm_range_t unexec_regions[MAX_UNEXEC_REGIONS]; | |
387 | ||
388 | static void | |
389 | unexec_regions_recorder (task_t task, void *rr, unsigned type, | |
390 | vm_range_t *ranges, unsigned num) | |
391 | { | |
392 | while (num && num_unexec_regions < MAX_UNEXEC_REGIONS) | |
393 | { | |
394 | unexec_regions[num_unexec_regions++] = *ranges; | |
395 | printf ("%#8x (sz: %#8x)\n", ranges->address, ranges->size); | |
396 | ranges++; num--; | |
397 | } | |
398 | if (num_unexec_regions == MAX_UNEXEC_REGIONS) | |
399 | fprintf (stderr, "malloc_freezedry_recorder: too many regions\n"); | |
400 | } | |
401 | ||
402 | static kern_return_t | |
403 | unexec_reader (task_t task, vm_address_t address, vm_size_t size, void **ptr) | |
404 | { | |
405 | *ptr = (void *) address; | |
406 | return KERN_SUCCESS; | |
407 | } | |
408 | ||
409 | void | |
410 | find_emacs_zone_regions () | |
411 | { | |
412 | num_unexec_regions = 0; | |
413 | ||
414 | emacs_zone->introspect->enumerator (mach_task_self(), 0, | |
415 | MALLOC_PTR_REGION_RANGE_TYPE | |
416 | | MALLOC_ADMIN_REGION_RANGE_TYPE, | |
417 | (vm_address_t) emacs_zone, | |
418 | unexec_reader, | |
419 | unexec_regions_recorder); | |
420 | } | |
421 | ||
1dd7ccf2 AC |
422 | static int |
423 | unexec_regions_sort_compare (const void *a, const void *b) | |
424 | { | |
425 | vm_address_t aa = ((vm_range_t *) a)->address; | |
426 | vm_address_t bb = ((vm_range_t *) b)->address; | |
427 | ||
428 | if (aa < bb) | |
429 | return -1; | |
430 | else if (aa > bb) | |
431 | return 1; | |
432 | else | |
433 | return 0; | |
434 | } | |
435 | ||
436 | static void | |
437 | unexec_regions_merge () | |
438 | { | |
439 | int i, n; | |
440 | vm_range_t r; | |
441 | ||
442 | qsort (unexec_regions, num_unexec_regions, sizeof (unexec_regions[0]), | |
443 | &unexec_regions_sort_compare); | |
444 | n = 0; | |
445 | r = unexec_regions[0]; | |
446 | for (i = 1; i < num_unexec_regions; i++) | |
447 | { | |
448 | if (r.address + r.size == unexec_regions[i].address) | |
449 | { | |
450 | r.size += unexec_regions[i].size; | |
451 | } | |
452 | else | |
453 | { | |
454 | unexec_regions[n++] = r; | |
455 | r = unexec_regions[i]; | |
456 | } | |
457 | } | |
458 | unexec_regions[n++] = r; | |
459 | num_unexec_regions = n; | |
460 | } | |
461 | ||
e0f712ba AC |
462 | |
463 | /* More informational messages routines. */ | |
464 | ||
465 | static void | |
466 | print_load_command_name (int lc) | |
467 | { | |
468 | switch (lc) | |
469 | { | |
470 | case LC_SEGMENT: | |
471 | printf ("LC_SEGMENT "); | |
472 | break; | |
473 | case LC_LOAD_DYLINKER: | |
474 | printf ("LC_LOAD_DYLINKER "); | |
475 | break; | |
476 | case LC_LOAD_DYLIB: | |
477 | printf ("LC_LOAD_DYLIB "); | |
478 | break; | |
479 | case LC_SYMTAB: | |
480 | printf ("LC_SYMTAB "); | |
481 | break; | |
482 | case LC_DYSYMTAB: | |
483 | printf ("LC_DYSYMTAB "); | |
484 | break; | |
485 | case LC_UNIXTHREAD: | |
486 | printf ("LC_UNIXTHREAD "); | |
487 | break; | |
488 | case LC_PREBOUND_DYLIB: | |
489 | printf ("LC_PREBOUND_DYLIB"); | |
490 | break; | |
491 | case LC_TWOLEVEL_HINTS: | |
492 | printf ("LC_TWOLEVEL_HINTS"); | |
493 | break; | |
494 | default: | |
495 | printf ("unknown "); | |
496 | } | |
497 | } | |
498 | ||
499 | static void | |
500 | print_load_command (struct load_command *lc) | |
501 | { | |
502 | print_load_command_name (lc->cmd); | |
503 | printf ("%8d", lc->cmdsize); | |
504 | ||
505 | if (lc->cmd == LC_SEGMENT) | |
506 | { | |
507 | struct segment_command *scp; | |
508 | struct section *sectp; | |
509 | int j; | |
510 | ||
511 | scp = (struct segment_command *) lc; | |
512 | printf (" %-16.16s %#10x %#8x\n", | |
513 | scp->segname, scp->vmaddr, scp->vmsize); | |
514 | ||
515 | sectp = (struct section *) (scp + 1); | |
516 | for (j = 0; j < scp->nsects; j++) | |
517 | { | |
518 | printf (" %-16.16s %#10x %#8x\n", | |
519 | sectp->sectname, sectp->addr, sectp->size); | |
520 | sectp++; | |
521 | } | |
522 | } | |
523 | else | |
524 | printf ("\n"); | |
525 | } | |
526 | ||
527 | /* Read header and load commands from input file. Store the latter in | |
528 | the global array lca. Store the total number of load commands in | |
529 | global variable nlc. */ | |
530 | static void | |
531 | read_load_commands () | |
532 | { | |
533 | int n, i, j; | |
534 | ||
535 | if (!unexec_read (&mh, sizeof (struct mach_header))) | |
536 | unexec_error ("cannot read mach-o header"); | |
537 | ||
538 | if (mh.magic != MH_MAGIC) | |
539 | unexec_error ("input file not in Mach-O format"); | |
540 | ||
541 | if (mh.filetype != MH_EXECUTE) | |
542 | unexec_error ("input Mach-O file is not an executable object file"); | |
543 | ||
544 | #if VERBOSE | |
545 | printf ("--- Header Information ---\n"); | |
546 | printf ("Magic = 0x%08x\n", mh.magic); | |
547 | printf ("CPUType = %d\n", mh.cputype); | |
548 | printf ("CPUSubType = %d\n", mh.cpusubtype); | |
549 | printf ("FileType = 0x%x\n", mh.filetype); | |
550 | printf ("NCmds = %d\n", mh.ncmds); | |
551 | printf ("SizeOfCmds = %d\n", mh.sizeofcmds); | |
552 | printf ("Flags = 0x%08x\n", mh.flags); | |
553 | #endif | |
554 | ||
555 | nlc = mh.ncmds; | |
556 | lca = (struct load_command **) malloc (nlc * sizeof (struct load_command *)); | |
177c0ea7 | 557 | |
e0f712ba AC |
558 | for (i = 0; i < nlc; i++) |
559 | { | |
560 | struct load_command lc; | |
561 | /* Load commands are variable-size: so read the command type and | |
562 | size first and then read the rest. */ | |
563 | if (!unexec_read (&lc, sizeof (struct load_command))) | |
564 | unexec_error ("cannot read load command"); | |
565 | lca[i] = (struct load_command *) malloc (lc.cmdsize); | |
566 | memcpy (lca[i], &lc, sizeof (struct load_command)); | |
567 | if (!unexec_read (lca[i] + 1, lc.cmdsize - sizeof (struct load_command))) | |
568 | unexec_error ("cannot read content of load command"); | |
569 | if (lc.cmd == LC_SEGMENT) | |
570 | { | |
571 | struct segment_command *scp = (struct segment_command *) lca[i]; | |
177c0ea7 | 572 | |
e0f712ba AC |
573 | if (scp->vmaddr + scp->vmsize > infile_lc_highest_addr) |
574 | infile_lc_highest_addr = scp->vmaddr + scp->vmsize; | |
575 | ||
576 | if (strncmp (scp->segname, SEG_TEXT, 16) == 0) | |
577 | { | |
578 | struct section *sectp = (struct section *) (scp + 1); | |
579 | int j; | |
580 | ||
581 | for (j = 0; j < scp->nsects; j++) | |
582 | if (sectp->offset < text_seg_lowest_offset) | |
583 | text_seg_lowest_offset = sectp->offset; | |
584 | } | |
585 | } | |
586 | } | |
587 | ||
588 | printf ("Highest address of load commands in input file: %#8x\n", | |
589 | infile_lc_highest_addr); | |
590 | ||
591 | printf ("Lowest offset of all sections in __TEXT segment: %#8x\n", | |
592 | text_seg_lowest_offset); | |
593 | ||
594 | printf ("--- List of Load Commands in Input File ---\n"); | |
595 | printf ("# cmd cmdsize name address size\n"); | |
596 | ||
597 | for (i = 0; i < nlc; i++) | |
598 | { | |
599 | printf ("%1d ", i); | |
600 | print_load_command (lca[i]); | |
601 | } | |
602 | } | |
603 | ||
604 | /* Copy a LC_SEGMENT load command other than the __DATA segment from | |
605 | the input file to the output file, adjusting the file offset of the | |
606 | segment and the file offsets of sections contained in it. */ | |
607 | static void | |
608 | copy_segment (struct load_command *lc) | |
609 | { | |
610 | struct segment_command *scp = (struct segment_command *) lc; | |
611 | unsigned long old_fileoff = scp->fileoff; | |
612 | struct section *sectp; | |
613 | int j; | |
614 | ||
615 | scp->fileoff += delta; | |
616 | ||
617 | sectp = (struct section *) (scp + 1); | |
618 | for (j = 0; j < scp->nsects; j++) | |
619 | { | |
620 | sectp->offset += delta; | |
621 | sectp++; | |
622 | } | |
623 | ||
624 | printf ("Writing segment %-16.16s at %#8x - %#8x (sz: %#8x)\n", | |
625 | scp->segname, scp->fileoff, scp->fileoff + scp->filesize, | |
626 | scp->filesize); | |
627 | ||
628 | if (!unexec_copy (scp->fileoff, old_fileoff, scp->filesize)) | |
629 | unexec_error ("cannot copy segment from input to output file"); | |
630 | if (!unexec_write (curr_header_offset, lc, lc->cmdsize)) | |
631 | unexec_error ("cannot write load command to header"); | |
632 | ||
633 | curr_header_offset += lc->cmdsize; | |
634 | } | |
635 | ||
636 | /* Copy a LC_SEGMENT load command for the __DATA segment in the input | |
637 | file to the output file. We assume that only one such segment load | |
638 | command exists in the input file and it contains the sections | |
639 | __data, __bss, __common, __la_symbol_ptr, __nl_symbol_ptr, and | |
640 | __dyld. The first three of these should be dumped from memory and | |
641 | the rest should be copied from the input file. Note that the | |
642 | sections __bss and __common contain no data in the input file | |
643 | because their flag fields have the value S_ZEROFILL. Dumping these | |
644 | from memory makes it necessary to adjust file offset fields in | |
645 | subsequently dumped load commands. Then, create new __DATA segment | |
646 | load commands for regions on the region list other than the one | |
647 | corresponding to the __DATA segment in the input file. */ | |
648 | static void | |
649 | copy_data_segment (struct load_command *lc) | |
650 | { | |
651 | struct segment_command *scp = (struct segment_command *) lc; | |
652 | struct section *sectp; | |
653 | int j; | |
654 | unsigned long header_offset, file_offset, old_file_offset; | |
655 | struct region_t *r; | |
656 | ||
657 | printf ("Writing segment %-16.16s at %#8x - %#8x (sz: %#8x)\n", | |
658 | scp->segname, scp->fileoff, scp->fileoff + scp->filesize, | |
659 | scp->filesize); | |
660 | ||
661 | if (delta != 0) | |
662 | unexec_error ("cannot handle multiple DATA segments in input file"); | |
663 | ||
664 | /* Offsets in the output file for writing the next section structure | |
665 | and segment data block, respectively. */ | |
666 | header_offset = curr_header_offset + sizeof (struct segment_command); | |
667 | ||
668 | sectp = (struct section *) (scp + 1); | |
669 | for (j = 0; j < scp->nsects; j++) | |
670 | { | |
671 | old_file_offset = sectp->offset; | |
672 | sectp->offset = sectp->addr - scp->vmaddr + scp->fileoff; | |
673 | /* The __data section is dumped from memory. The __bss and | |
674 | __common sections are also dumped from memory but their flag | |
675 | fields require changing (from S_ZEROFILL to S_REGULAR). The | |
676 | other three kinds of sections are just copied from the input | |
677 | file. */ | |
678 | if (strncmp (sectp->sectname, SECT_DATA, 16) == 0) | |
679 | { | |
680 | if (!unexec_write (sectp->offset, (void *) sectp->addr, sectp->size)) | |
681 | unexec_error ("cannot write section %s", SECT_DATA); | |
682 | if (!unexec_write (header_offset, sectp, sizeof (struct section))) | |
683 | unexec_error ("cannot write section %s's header", SECT_DATA); | |
684 | } | |
685 | else if (strncmp (sectp->sectname, SECT_BSS, 16) == 0 | |
686 | || strncmp (sectp->sectname, SECT_COMMON, 16) == 0) | |
687 | { | |
688 | sectp->flags = S_REGULAR; | |
689 | if (!unexec_write (sectp->offset, (void *) sectp->addr, sectp->size)) | |
690 | unexec_error ("cannot write section %s", SECT_DATA); | |
691 | if (!unexec_write (header_offset, sectp, sizeof (struct section))) | |
692 | unexec_error ("cannot write section %s's header", SECT_DATA); | |
693 | } | |
694 | else if (strncmp (sectp->sectname, "__la_symbol_ptr", 16) == 0 | |
695 | || strncmp (sectp->sectname, "__nl_symbol_ptr", 16) == 0 | |
696 | || strncmp (sectp->sectname, "__dyld", 16) == 0 | |
7290a344 AC |
697 | || strncmp (sectp->sectname, "__const", 16) == 0 |
698 | || strncmp (sectp->sectname, "__cfstring", 16) == 0) | |
e0f712ba AC |
699 | { |
700 | if (!unexec_copy (sectp->offset, old_file_offset, sectp->size)) | |
701 | unexec_error ("cannot copy section %s", sectp->sectname); | |
702 | if (!unexec_write (header_offset, sectp, sizeof (struct section))) | |
703 | unexec_error ("cannot write section %s's header", sectp->sectname); | |
704 | } | |
705 | else | |
706 | unexec_error ("unrecognized section name in __DATA segment"); | |
177c0ea7 | 707 | |
e0f712ba AC |
708 | printf (" section %-16.16s at %#8x - %#8x (sz: %#8x)\n", |
709 | sectp->sectname, sectp->offset, sectp->offset + sectp->size, | |
710 | sectp->size); | |
711 | ||
712 | header_offset += sizeof (struct section); | |
713 | sectp++; | |
714 | } | |
715 | ||
716 | /* The new filesize of the segment is set to its vmsize because data | |
717 | blocks for segments must start at region boundaries. Note that | |
718 | this may leave unused locations at the end of the segment data | |
719 | block because the total of the sizes of all sections in the | |
720 | segment is generally smaller than vmsize. */ | |
721 | delta = scp->vmsize - scp->filesize; | |
722 | scp->filesize = scp->vmsize; | |
723 | if (!unexec_write (curr_header_offset, scp, sizeof (struct segment_command))) | |
724 | unexec_error ("cannot write header of __DATA segment"); | |
725 | curr_header_offset += lc->cmdsize; | |
726 | ||
727 | /* Create new __DATA segment load commands for regions on the region | |
728 | list that do not corresponding to any segment load commands in | |
729 | the input file. | |
730 | */ | |
731 | file_offset = scp->fileoff + scp->filesize; | |
732 | for (j = 0; j < num_unexec_regions; j++) | |
733 | { | |
734 | struct segment_command sc; | |
177c0ea7 | 735 | |
e0f712ba AC |
736 | sc.cmd = LC_SEGMENT; |
737 | sc.cmdsize = sizeof (struct segment_command); | |
738 | strncpy (sc.segname, SEG_DATA, 16); | |
739 | sc.vmaddr = unexec_regions[j].address; | |
740 | sc.vmsize = unexec_regions[j].size; | |
741 | sc.fileoff = file_offset; | |
742 | sc.filesize = unexec_regions[j].size; | |
743 | sc.maxprot = VM_PROT_READ | VM_PROT_WRITE; | |
744 | sc.initprot = VM_PROT_READ | VM_PROT_WRITE; | |
745 | sc.nsects = 0; | |
746 | sc.flags = 0; | |
177c0ea7 | 747 | |
e0f712ba AC |
748 | printf ("Writing segment %-16.16s at %#8x - %#8x (sz: %#8x)\n", |
749 | sc.segname, sc.fileoff, sc.fileoff + sc.filesize, | |
750 | sc.filesize); | |
751 | ||
752 | if (!unexec_write (sc.fileoff, (void *) sc.vmaddr, sc.vmsize)) | |
753 | unexec_error ("cannot write new __DATA segment"); | |
754 | delta += sc.filesize; | |
755 | file_offset += sc.filesize; | |
177c0ea7 | 756 | |
e0f712ba AC |
757 | if (!unexec_write (curr_header_offset, &sc, sc.cmdsize)) |
758 | unexec_error ("cannot write new __DATA segment's header"); | |
759 | curr_header_offset += sc.cmdsize; | |
760 | mh.ncmds++; | |
761 | } | |
762 | } | |
763 | ||
764 | /* Copy a LC_SYMTAB load command from the input file to the output | |
765 | file, adjusting the file offset fields. */ | |
766 | static void | |
767 | copy_symtab (struct load_command *lc) | |
768 | { | |
769 | struct symtab_command *stp = (struct symtab_command *) lc; | |
770 | ||
771 | stp->symoff += delta; | |
772 | stp->stroff += delta; | |
773 | ||
774 | printf ("Writing LC_SYMTAB command\n"); | |
775 | ||
776 | if (!unexec_write (curr_header_offset, lc, lc->cmdsize)) | |
777 | unexec_error ("cannot write symtab command to header"); | |
778 | ||
779 | curr_header_offset += lc->cmdsize; | |
780 | } | |
781 | ||
043131c4 AC |
782 | /* Fix up relocation entries. */ |
783 | static void | |
784 | unrelocate (const char *name, off_t reloff, int nrel) | |
785 | { | |
786 | int i, unreloc_count; | |
787 | struct relocation_info reloc_info; | |
788 | struct scattered_relocation_info *sc_reloc_info | |
789 | = (struct scattered_relocation_info *) &reloc_info; | |
790 | ||
791 | for (unreloc_count = 0, i = 0; i < nrel; i++) | |
792 | { | |
793 | if (lseek (infd, reloff, L_SET) != reloff) | |
794 | unexec_error ("unrelocate: %s:%d cannot seek to reloc_info", name, i); | |
795 | if (!unexec_read (&reloc_info, sizeof (reloc_info))) | |
796 | unexec_error ("unrelocate: %s:%d cannot read reloc_info", name, i); | |
797 | reloff += sizeof (reloc_info); | |
798 | ||
799 | if (sc_reloc_info->r_scattered == 0) | |
800 | switch (reloc_info.r_type) | |
801 | { | |
802 | case GENERIC_RELOC_VANILLA: | |
803 | if (reloc_info.r_address >= data_segment_scp->vmaddr | |
804 | && reloc_info.r_address < (data_segment_scp->vmaddr | |
805 | + data_segment_scp->vmsize)) | |
806 | { | |
807 | off_t src_off = data_segment_old_fileoff | |
808 | + reloc_info.r_address - data_segment_scp->vmaddr; | |
809 | off_t dst_off = data_segment_scp->fileoff | |
810 | + reloc_info.r_address - data_segment_scp->vmaddr; | |
811 | ||
812 | if (!unexec_copy (dst_off, src_off, 1 << reloc_info.r_length)) | |
813 | unexec_error ("unrelocate: %s:%d cannot copy original value", | |
814 | name, i); | |
815 | unreloc_count++; | |
816 | } | |
817 | break; | |
818 | default: | |
819 | unexec_error ("unrelocate: %s:%d cannot handle type = %d", | |
820 | name, i, reloc_info.r_type); | |
821 | } | |
822 | else | |
823 | switch (sc_reloc_info->r_type) | |
824 | { | |
825 | #if defined (__ppc__) | |
826 | case PPC_RELOC_PB_LA_PTR: | |
827 | /* nothing to do for prebound lazy pointer */ | |
828 | break; | |
829 | #endif | |
830 | default: | |
831 | unexec_error ("unrelocate: %s:%d cannot handle scattered type = %d", | |
832 | name, i, sc_reloc_info->r_type); | |
833 | } | |
834 | } | |
835 | ||
836 | if (nrel > 0) | |
837 | printf ("Fixed up %d/%d %s relocation entries in data segment.\n", | |
838 | unreloc_count, nrel, name); | |
839 | } | |
840 | ||
e0f712ba AC |
841 | /* Copy a LC_DYSYMTAB load command from the input file to the output |
842 | file, adjusting the file offset fields. */ | |
843 | static void | |
844 | copy_dysymtab (struct load_command *lc) | |
845 | { | |
846 | struct dysymtab_command *dstp = (struct dysymtab_command *) lc; | |
847 | ||
043131c4 AC |
848 | unrelocate ("local", dstp->locreloff, dstp->nlocrel); |
849 | unrelocate ("external", dstp->extreloff, dstp->nextrel); | |
e0f712ba AC |
850 | |
851 | if (dstp->nextrel > 0) { | |
852 | dstp->extreloff += delta; | |
853 | } | |
854 | ||
855 | if (dstp->nlocrel > 0) { | |
856 | dstp->locreloff += delta; | |
857 | } | |
858 | ||
859 | if (dstp->nindirectsyms > 0) | |
860 | dstp->indirectsymoff += delta; | |
861 | ||
862 | printf ("Writing LC_DYSYMTAB command\n"); | |
863 | ||
864 | if (!unexec_write (curr_header_offset, lc, lc->cmdsize)) | |
865 | unexec_error ("cannot write symtab command to header"); | |
866 | ||
867 | curr_header_offset += lc->cmdsize; | |
868 | } | |
869 | ||
40e6ff95 ST |
870 | /* Copy a LC_TWOLEVEL_HINTS load command from the input file to the output |
871 | file, adjusting the file offset fields. */ | |
872 | static void | |
873 | copy_twolevelhints (struct load_command *lc) | |
874 | { | |
875 | struct twolevel_hints_command *tlhp = (struct twolevel_hints_command *) lc; | |
876 | ||
877 | if (tlhp->nhints > 0) { | |
878 | tlhp->offset += delta; | |
879 | } | |
880 | ||
881 | printf ("Writing LC_TWOLEVEL_HINTS command\n"); | |
882 | ||
883 | if (!unexec_write (curr_header_offset, lc, lc->cmdsize)) | |
884 | unexec_error ("cannot write two level hint command to header"); | |
885 | ||
886 | curr_header_offset += lc->cmdsize; | |
887 | } | |
888 | ||
e0f712ba AC |
889 | /* Copy other kinds of load commands from the input file to the output |
890 | file, ones that do not require adjustments of file offsets. */ | |
891 | static void | |
892 | copy_other (struct load_command *lc) | |
893 | { | |
894 | printf ("Writing "); | |
895 | print_load_command_name (lc->cmd); | |
896 | printf (" command\n"); | |
897 | ||
898 | if (!unexec_write (curr_header_offset, lc, lc->cmdsize)) | |
899 | unexec_error ("cannot write symtab command to header"); | |
900 | ||
901 | curr_header_offset += lc->cmdsize; | |
902 | } | |
903 | ||
904 | /* Loop through all load commands and dump them. Then write the Mach | |
905 | header. */ | |
906 | static void | |
907 | dump_it () | |
908 | { | |
909 | int i; | |
910 | ||
911 | printf ("--- Load Commands written to Output File ---\n"); | |
912 | ||
913 | for (i = 0; i < nlc; i++) | |
914 | switch (lca[i]->cmd) | |
915 | { | |
916 | case LC_SEGMENT: | |
917 | { | |
918 | struct segment_command *scp = (struct segment_command *) lca[i]; | |
919 | if (strncmp (scp->segname, SEG_DATA, 16) == 0) | |
920 | { | |
043131c4 AC |
921 | /* save data segment file offset and segment_command for |
922 | unrelocate */ | |
923 | data_segment_old_fileoff = scp->fileoff; | |
924 | data_segment_scp = scp; | |
925 | ||
e0f712ba AC |
926 | copy_data_segment (lca[i]); |
927 | } | |
928 | else | |
929 | { | |
930 | copy_segment (lca[i]); | |
931 | } | |
932 | } | |
933 | break; | |
934 | case LC_SYMTAB: | |
935 | copy_symtab (lca[i]); | |
936 | break; | |
937 | case LC_DYSYMTAB: | |
938 | copy_dysymtab (lca[i]); | |
939 | break; | |
40e6ff95 ST |
940 | case LC_TWOLEVEL_HINTS: |
941 | copy_twolevelhints (lca[i]); | |
942 | break; | |
e0f712ba AC |
943 | default: |
944 | copy_other (lca[i]); | |
945 | break; | |
946 | } | |
947 | ||
948 | if (curr_header_offset > text_seg_lowest_offset) | |
949 | unexec_error ("not enough room for load commands for new __DATA segments"); | |
950 | ||
951 | printf ("%d unused bytes follow Mach-O header\n", | |
952 | text_seg_lowest_offset - curr_header_offset); | |
953 | ||
954 | mh.sizeofcmds = curr_header_offset - sizeof (struct mach_header); | |
955 | if (!unexec_write (0, &mh, sizeof (struct mach_header))) | |
956 | unexec_error ("cannot write final header contents"); | |
957 | } | |
958 | ||
959 | /* Take a snapshot of Emacs and make a Mach-O format executable file | |
960 | from it. The file names of the output and input files are outfile | |
961 | and infile, respectively. The three other parameters are | |
962 | ignored. */ | |
963 | void | |
964 | unexec (char *outfile, char *infile, void *start_data, void *start_bss, | |
965 | void *entry_address) | |
966 | { | |
967 | infd = open (infile, O_RDONLY, 0); | |
968 | if (infd < 0) | |
969 | { | |
970 | unexec_error ("cannot open input file `%s'", infile); | |
971 | } | |
177c0ea7 | 972 | |
e0f712ba AC |
973 | outfd = open (outfile, O_WRONLY | O_TRUNC | O_CREAT, 0755); |
974 | if (outfd < 0) | |
975 | { | |
976 | close (infd); | |
977 | unexec_error ("cannot open output file `%s'", outfile); | |
978 | } | |
979 | ||
980 | build_region_list (); | |
981 | read_load_commands (); | |
982 | ||
983 | find_emacs_zone_regions (); | |
1dd7ccf2 | 984 | unexec_regions_merge (); |
e0f712ba AC |
985 | |
986 | in_dumped_exec = 1; | |
987 | ||
988 | dump_it (); | |
989 | ||
990 | close (outfd); | |
991 | } | |
992 | ||
993 | ||
994 | void | |
995 | unexec_init_emacs_zone () | |
996 | { | |
997 | emacs_zone = malloc_create_zone (0, 0); | |
998 | malloc_set_zone_name (emacs_zone, "EmacsZone"); | |
999 | } | |
1000 | ||
1001 | int | |
1002 | ptr_in_unexec_regions (void *ptr) | |
1003 | { | |
1004 | int i; | |
1005 | ||
1006 | for (i = 0; i < num_unexec_regions; i++) | |
1007 | if ((vm_address_t) ptr - unexec_regions[i].address | |
1008 | < unexec_regions[i].size) | |
1009 | return 1; | |
1010 | ||
1011 | return 0; | |
1012 | } | |
1013 | ||
1014 | void * | |
1015 | unexec_malloc (size_t size) | |
1016 | { | |
1017 | if (in_dumped_exec) | |
1018 | return malloc (size); | |
1019 | else | |
1020 | return malloc_zone_malloc (emacs_zone, size); | |
1021 | } | |
1022 | ||
1023 | void * | |
1024 | unexec_realloc (void *old_ptr, size_t new_size) | |
1025 | { | |
1026 | if (in_dumped_exec) | |
1027 | if (ptr_in_unexec_regions (old_ptr)) | |
1028 | { | |
1029 | char *p = malloc (new_size); | |
1030 | /* 2002-04-15 T. Ikegami <ikegami@adam.uprr.pr>. The original | |
1031 | code to get size failed to reallocate read_buffer | |
1032 | (lread.c). */ | |
82122254 | 1033 | int old_size = malloc_default_zone()->size (emacs_zone, old_ptr); |
e0f712ba AC |
1034 | int size = new_size > old_size ? old_size : new_size; |
1035 | ||
1036 | if (size) | |
1037 | memcpy (p, old_ptr, size); | |
1038 | return p; | |
1039 | } | |
1040 | else | |
1041 | return realloc (old_ptr, new_size); | |
1042 | else | |
1043 | return malloc_zone_realloc (emacs_zone, old_ptr, new_size); | |
1044 | } | |
1045 | ||
1046 | void | |
1047 | unexec_free (void *ptr) | |
1048 | { | |
1049 | if (in_dumped_exec) | |
1050 | { | |
1051 | if (!ptr_in_unexec_regions (ptr)) | |
1052 | free (ptr); | |
1053 | } | |
1054 | else | |
1055 | malloc_zone_free (emacs_zone, ptr); | |
1056 | } | |
ab5796a9 MB |
1057 | |
1058 | /* arch-tag: 1a784f7b-a184-4c4f-9544-da8619593d72 | |
1059 | (do not change this comment) */ |