1 /* Dump Emacs in Mach-O format for use on Mac OS X.
2 Copyright (C) 2001, 2002, 2003, 2004, 2005,
3 2006, 2007, 2008, 2009, 2010, 2011 Free Software Foundation, Inc.
5 This file is part of GNU Emacs.
7 GNU Emacs is free software: you can redistribute it and/or modify
8 it under the terms of the GNU General Public License as published by
9 the Free Software Foundation, either version 3 of the License, or
10 (at your option) any later version.
12 GNU Emacs is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
17 You should have received a copy of the GNU General Public License
18 along with GNU Emacs. If not, see <http://www.gnu.org/licenses/>. */
20 /* Contributed by Andrew Choi (akochoi@mac.com). */
22 /* Documentation note.
24 Consult the following documents/files for a description of the
25 Mach-O format: the file loader.h, man pages for Mach-O and ld, old
26 NEXTSTEP documents of the Mach-O format. The tool otool dumps the
27 mach header (-h option) and the load commands (-l option) in a
28 Mach-O file. The tool nm on Mac OS X displays the symbol table in
29 a Mach-O file. For examples of unexec for the Mach-O format, see
30 the file unexnext.c in the GNU Emacs distribution, the file
31 unexdyld.c in the Darwin port of GNU Emacs 20.7, and unexdyld.c in
32 the Darwin port of XEmacs 21.1. Also the Darwin Libc source
33 contains the source code for malloc_freezedry and malloc_jumpstart.
34 Read that to see what they do. This file was written completely
35 from scratch, making use of information from the above sources. */
37 /* The Mac OS X implementation of unexec makes use of Darwin's `zone'
38 memory allocator. All calls to malloc, realloc, and free in Emacs
39 are redirected to unexec_malloc, unexec_realloc, and unexec_free in
40 this file. When temacs is run, all memory requests are handled in
41 the zone EmacsZone. The Darwin memory allocator library calls
42 maintain the data structures to manage this zone. Dumping writes
43 its contents to data segments of the executable file. When emacs
44 is run, the loader recreates the contents of the zone in memory.
45 However since the initialization routine of the zone memory
46 allocator is run again, this `zone' can no longer be used as a
47 heap. That is why emacs uses the ordinary malloc system call to
48 allocate memory. Also, when a block of memory needs to be
49 reallocated and the new size is larger than the old one, a new
50 block must be obtained by malloc and the old contents copied to
53 /* Peculiarity of the Mach-O files generated by ld in Mac OS X
54 (possible causes of future bugs if changed).
56 The file offset of the start of the __TEXT segment is zero. Since
57 the Mach header and load commands are located at the beginning of a
58 Mach-O file, copying the contents of the __TEXT segment from the
59 input file overwrites them in the output file. Despite this,
60 unexec works fine as written below because the segment load command
61 for __TEXT appears, and is therefore processed, before all other
62 load commands except the segment load command for __PAGEZERO, which
65 Although the file offset of the start of the __TEXT segment is
66 zero, none of the sections it contains actually start there. In
67 fact, the earliest one starts a few hundred bytes beyond the end of
68 the last load command. The linker option -headerpad controls the
69 minimum size of this padding. Its setting can be changed in
70 s/darwin.h. A value of 0x690, e.g., leaves room for 30 additional
71 load commands for the newly created __DATA segments (at 56 bytes
72 each). Unexec fails if there is not enough room for these new
75 The __TEXT segment contains the sections __text, __cstring,
76 __picsymbol_stub, and __const and the __DATA segment contains the
77 sections __data, __la_symbol_ptr, __nl_symbol_ptr, __dyld, __bss,
78 and __common. The other segments do not contain any sections.
79 These sections are copied from the input file to the output file,
80 except for __data, __bss, and __common, which are dumped from
81 memory. The types of the sections __bss and __common are changed
82 from S_ZEROFILL to S_REGULAR. Note that the number of sections and
83 their relative order in the input and output files remain
84 unchanged. Otherwise all n_sect fields in the nlist records in the
85 symbol table (specified by the LC_SYMTAB load command) will have to
86 be changed accordingly.
89 /* config.h #define:s malloc/realloc/free and then includes stdlib.h.
90 We want the undefined versions, but if config.h includes stdlib.h
91 with the #define:s in place, the prototypes will be wrong and we get
92 warnings. To prevent that, include stdlib.h before config.h. */
102 #include <sys/types.h>
104 #include <mach/mach.h>
105 #include <mach-o/loader.h>
106 #include <mach-o/reloc.h>
107 #if defined (__ppc__)
108 #include <mach-o/ppc/reloc.h>
110 #ifdef HAVE_MALLOC_MALLOC_H
111 #include <malloc/malloc.h>
113 #include <objc/malloc.h>
119 #define mach_header mach_header_64
120 #define segment_command segment_command_64
121 #undef VM_REGION_BASIC_INFO_COUNT
122 #define VM_REGION_BASIC_INFO_COUNT VM_REGION_BASIC_INFO_COUNT_64
123 #undef VM_REGION_BASIC_INFO
124 #define VM_REGION_BASIC_INFO VM_REGION_BASIC_INFO_64
126 #define LC_SEGMENT LC_SEGMENT_64
127 #define vm_region vm_region_64
128 #define section section_64
130 #define MH_MAGIC MH_MAGIC_64
135 /* Size of buffer used to copy data from the input file to the output
136 file in function unexec_copy. */
137 #define UNEXEC_COPY_BUFSZ 1024
139 /* Regions with memory addresses above this value are assumed to be
140 mapped to dynamically loaded libraries and will not be dumped. */
141 #define VM_DATA_TOP (20 * 1024 * 1024)
143 /* Type of an element on the list of regions to be dumped. */
145 vm_address_t address
;
147 vm_prot_t protection
;
148 vm_prot_t max_protection
;
150 struct region_t
*next
;
153 /* Head and tail of the list of regions to be dumped. */
154 static struct region_t
*region_list_head
= 0;
155 static struct region_t
*region_list_tail
= 0;
157 /* Pointer to array of load commands. */
158 static struct load_command
**lca
;
160 /* Number of load commands. */
163 /* The highest VM address of segments loaded by the input file.
164 Regions with addresses beyond this are assumed to be allocated
165 dynamically and thus require dumping. */
166 static vm_address_t infile_lc_highest_addr
= 0;
168 /* The lowest file offset used by the all sections in the __TEXT
169 segments. This leaves room at the beginning of the file to store
170 the Mach-O header. Check this value against header size to ensure
171 the added load commands for the new __DATA segments did not
172 overwrite any of the sections in the __TEXT segment. */
173 static unsigned long text_seg_lowest_offset
= 0x10000000;
176 static struct mach_header mh
;
178 /* Offset at which the next load command should be written. */
179 static unsigned long curr_header_offset
= sizeof (struct mach_header
);
181 /* Offset at which the next segment should be written. */
182 static unsigned long curr_file_offset
= 0;
184 static unsigned long pagesize
;
185 #define ROUNDUP_TO_PAGE_BOUNDARY(x) (((x) + pagesize - 1) & ~(pagesize - 1))
187 static int infd
, outfd
;
189 static int in_dumped_exec
= 0;
191 static malloc_zone_t
*emacs_zone
;
193 /* file offset of input file's data segment */
194 static off_t data_segment_old_fileoff
= 0;
196 static struct segment_command
*data_segment_scp
;
198 static void unexec_error (const char *format
, ...) NO_RETURN
;
200 /* Read N bytes from infd into memory starting at address DEST.
201 Return true if successful, false otherwise. */
203 unexec_read (void *dest
, size_t n
)
205 return n
== read (infd
, dest
, n
);
208 /* Write COUNT bytes from memory starting at address SRC to outfd
209 starting at offset DEST. Return true if successful, false
212 unexec_write (off_t dest
, const void *src
, size_t count
)
214 if (lseek (outfd
, dest
, SEEK_SET
) != dest
)
217 return write (outfd
, src
, count
) == count
;
220 /* Write COUNT bytes of zeros to outfd starting at offset DEST.
221 Return true if successful, false otherwise. */
223 unexec_write_zero (off_t dest
, size_t count
)
225 char buf
[UNEXEC_COPY_BUFSZ
];
228 memset (buf
, 0, UNEXEC_COPY_BUFSZ
);
229 if (lseek (outfd
, dest
, SEEK_SET
) != dest
)
234 bytes
= count
> UNEXEC_COPY_BUFSZ
? UNEXEC_COPY_BUFSZ
: count
;
235 if (write (outfd
, buf
, bytes
) != bytes
)
243 /* Copy COUNT bytes from starting offset SRC in infd to starting
244 offset DEST in outfd. Return true if successful, false
247 unexec_copy (off_t dest
, off_t src
, ssize_t count
)
250 ssize_t bytes_to_read
;
252 char buf
[UNEXEC_COPY_BUFSZ
];
254 if (lseek (infd
, src
, SEEK_SET
) != src
)
257 if (lseek (outfd
, dest
, SEEK_SET
) != dest
)
262 bytes_to_read
= count
> UNEXEC_COPY_BUFSZ
? UNEXEC_COPY_BUFSZ
: count
;
263 bytes_read
= read (infd
, buf
, bytes_to_read
);
266 if (write (outfd
, buf
, bytes_read
) != bytes_read
)
274 /* Debugging and informational messages routines. */
277 unexec_error (const char *format
, ...)
281 va_start (ap
, format
);
282 fprintf (stderr
, "unexec: ");
283 vfprintf (stderr
, format
, ap
);
284 fprintf (stderr
, "\n");
290 print_prot (vm_prot_t prot
)
292 if (prot
== VM_PROT_NONE
)
296 putchar (prot
& VM_PROT_READ
? 'r' : ' ');
297 putchar (prot
& VM_PROT_WRITE
? 'w' : ' ');
298 putchar (prot
& VM_PROT_EXECUTE
? 'x' : ' ');
304 print_region (vm_address_t address
, vm_size_t size
, vm_prot_t prot
,
307 printf ("%#10lx %#8lx ", (long) address
, (long) size
);
310 print_prot (max_prot
);
315 print_region_list (void)
319 printf (" address size prot maxp\n");
321 for (r
= region_list_head
; r
; r
= r
->next
)
322 print_region (r
->address
, r
->size
, r
->protection
, r
->max_protection
);
328 task_t target_task
= mach_task_self ();
329 vm_address_t address
= (vm_address_t
) 0;
331 struct vm_region_basic_info info
;
332 mach_msg_type_number_t info_count
= VM_REGION_BASIC_INFO_COUNT
;
333 mach_port_t object_name
;
335 printf (" address size prot maxp\n");
337 while (vm_region (target_task
, &address
, &size
, VM_REGION_BASIC_INFO
,
338 (vm_region_info_t
) &info
, &info_count
, &object_name
)
339 == KERN_SUCCESS
&& info_count
== VM_REGION_BASIC_INFO_COUNT
)
341 print_region (address
, size
, info
.protection
, info
.max_protection
);
343 if (object_name
!= MACH_PORT_NULL
)
344 mach_port_deallocate (target_task
, object_name
);
350 /* Build the list of regions that need to be dumped. Regions with
351 addresses above VM_DATA_TOP are omitted. Adjacent regions with
352 identical protection are merged. Note that non-writable regions
353 cannot be omitted because they some regions created at run time are
356 build_region_list (void)
358 task_t target_task
= mach_task_self ();
359 vm_address_t address
= (vm_address_t
) 0;
361 struct vm_region_basic_info info
;
362 mach_msg_type_number_t info_count
= VM_REGION_BASIC_INFO_COUNT
;
363 mach_port_t object_name
;
367 printf ("--- List of All Regions ---\n");
368 printf (" address size prot maxp\n");
371 while (vm_region (target_task
, &address
, &size
, VM_REGION_BASIC_INFO
,
372 (vm_region_info_t
) &info
, &info_count
, &object_name
)
373 == KERN_SUCCESS
&& info_count
== VM_REGION_BASIC_INFO_COUNT
)
375 /* Done when we reach addresses of shared libraries, which are
376 loaded in high memory. */
377 if (address
>= VM_DATA_TOP
)
381 print_region (address
, size
, info
.protection
, info
.max_protection
);
384 /* If a region immediately follows the previous one (the one
385 most recently added to the list) and has identical
386 protection, merge it with the latter. Otherwise create a
387 new list element for it. */
389 && info
.protection
== region_list_tail
->protection
390 && info
.max_protection
== region_list_tail
->max_protection
391 && region_list_tail
->address
+ region_list_tail
->size
== address
)
393 region_list_tail
->size
+= size
;
397 r
= (struct region_t
*) malloc (sizeof (struct region_t
));
400 unexec_error ("cannot allocate region structure");
402 r
->address
= address
;
404 r
->protection
= info
.protection
;
405 r
->max_protection
= info
.max_protection
;
408 if (region_list_head
== 0)
410 region_list_head
= r
;
411 region_list_tail
= r
;
415 region_list_tail
->next
= r
;
416 region_list_tail
= r
;
419 /* Deallocate (unused) object name returned by
421 if (object_name
!= MACH_PORT_NULL
)
422 mach_port_deallocate (target_task
, object_name
);
428 printf ("--- List of Regions to be Dumped ---\n");
429 print_region_list ();
433 #define MAX_UNEXEC_REGIONS 400
435 static int num_unexec_regions
;
439 } unexec_region_info
;
440 static unexec_region_info unexec_regions
[MAX_UNEXEC_REGIONS
];
443 unexec_regions_recorder (task_t task
, void *rr
, unsigned type
,
444 vm_range_t
*ranges
, unsigned num
)
449 while (num
&& num_unexec_regions
< MAX_UNEXEC_REGIONS
)
451 /* Subtract the size of trailing null bytes from filesize. It
452 can be smaller than vmsize in segment commands. In such a
453 case, trailing bytes are initialized with zeros. */
454 for (p
= ranges
->address
+ ranges
->size
; p
> ranges
->address
; p
--)
455 if (*(((char *) p
)-1))
457 filesize
= p
- ranges
->address
;
459 unexec_regions
[num_unexec_regions
].filesize
= filesize
;
460 unexec_regions
[num_unexec_regions
++].range
= *ranges
;
461 printf ("%#10lx (sz: %#8lx/%#8lx)\n", (long) (ranges
->address
),
462 (long) filesize
, (long) (ranges
->size
));
468 unexec_reader (task_t task
, vm_address_t address
, vm_size_t size
, void **ptr
)
470 *ptr
= (void *) address
;
475 find_emacs_zone_regions (void)
477 num_unexec_regions
= 0;
479 emacs_zone
->introspect
->enumerator (mach_task_self(), 0,
480 MALLOC_PTR_REGION_RANGE_TYPE
481 | MALLOC_ADMIN_REGION_RANGE_TYPE
,
482 (vm_address_t
) emacs_zone
,
484 unexec_regions_recorder
);
486 if (num_unexec_regions
== MAX_UNEXEC_REGIONS
)
487 unexec_error ("find_emacs_zone_regions: too many regions");
491 unexec_regions_sort_compare (const void *a
, const void *b
)
493 vm_address_t aa
= ((unexec_region_info
*) a
)->range
.address
;
494 vm_address_t bb
= ((unexec_region_info
*) b
)->range
.address
;
505 unexec_regions_merge (void)
508 unexec_region_info r
;
511 qsort (unexec_regions
, num_unexec_regions
, sizeof (unexec_regions
[0]),
512 &unexec_regions_sort_compare
);
514 r
= unexec_regions
[0];
515 padsize
= r
.range
.address
& (pagesize
- 1);
518 r
.range
.address
-= padsize
;
519 r
.range
.size
+= padsize
;
520 r
.filesize
+= padsize
;
522 for (i
= 1; i
< num_unexec_regions
; i
++)
524 if (r
.range
.address
+ r
.range
.size
== unexec_regions
[i
].range
.address
525 && r
.range
.size
- r
.filesize
< 2 * pagesize
)
527 r
.filesize
= r
.range
.size
+ unexec_regions
[i
].filesize
;
528 r
.range
.size
+= unexec_regions
[i
].range
.size
;
532 unexec_regions
[n
++] = r
;
533 r
= unexec_regions
[i
];
534 padsize
= r
.range
.address
& (pagesize
- 1);
537 if ((unexec_regions
[n
-1].range
.address
538 + unexec_regions
[n
-1].range
.size
) == r
.range
.address
)
539 unexec_regions
[n
-1].range
.size
-= padsize
;
541 r
.range
.address
-= padsize
;
542 r
.range
.size
+= padsize
;
543 r
.filesize
+= padsize
;
547 unexec_regions
[n
++] = r
;
548 num_unexec_regions
= n
;
552 /* More informational messages routines. */
555 print_load_command_name (int lc
)
561 printf ("LC_SEGMENT ");
563 printf ("LC_SEGMENT_64 ");
566 case LC_LOAD_DYLINKER
:
567 printf ("LC_LOAD_DYLINKER ");
570 printf ("LC_LOAD_DYLIB ");
573 printf ("LC_SYMTAB ");
576 printf ("LC_DYSYMTAB ");
579 printf ("LC_UNIXTHREAD ");
581 case LC_PREBOUND_DYLIB
:
582 printf ("LC_PREBOUND_DYLIB");
584 case LC_TWOLEVEL_HINTS
:
585 printf ("LC_TWOLEVEL_HINTS");
594 printf ("LC_DYLD_INFO ");
596 case LC_DYLD_INFO_ONLY
:
597 printf ("LC_DYLD_INFO_ONLY");
606 print_load_command (struct load_command
*lc
)
608 print_load_command_name (lc
->cmd
);
609 printf ("%8d", lc
->cmdsize
);
611 if (lc
->cmd
== LC_SEGMENT
)
613 struct segment_command
*scp
;
614 struct section
*sectp
;
617 scp
= (struct segment_command
*) lc
;
618 printf (" %-16.16s %#10lx %#8lx\n",
619 scp
->segname
, (long) (scp
->vmaddr
), (long) (scp
->vmsize
));
621 sectp
= (struct section
*) (scp
+ 1);
622 for (j
= 0; j
< scp
->nsects
; j
++)
624 printf (" %-16.16s %#10lx %#8lx\n",
625 sectp
->sectname
, (long) (sectp
->addr
), (long) (sectp
->size
));
633 /* Read header and load commands from input file. Store the latter in
634 the global array lca. Store the total number of load commands in
635 global variable nlc. */
637 read_load_commands (void)
641 if (!unexec_read (&mh
, sizeof (struct mach_header
)))
642 unexec_error ("cannot read mach-o header");
644 if (mh
.magic
!= MH_MAGIC
)
645 unexec_error ("input file not in Mach-O format");
647 if (mh
.filetype
!= MH_EXECUTE
)
648 unexec_error ("input Mach-O file is not an executable object file");
651 printf ("--- Header Information ---\n");
652 printf ("Magic = 0x%08x\n", mh
.magic
);
653 printf ("CPUType = %d\n", mh
.cputype
);
654 printf ("CPUSubType = %d\n", mh
.cpusubtype
);
655 printf ("FileType = 0x%x\n", mh
.filetype
);
656 printf ("NCmds = %d\n", mh
.ncmds
);
657 printf ("SizeOfCmds = %d\n", mh
.sizeofcmds
);
658 printf ("Flags = 0x%08x\n", mh
.flags
);
662 lca
= (struct load_command
**) malloc (nlc
* sizeof (struct load_command
*));
664 for (i
= 0; i
< nlc
; i
++)
666 struct load_command lc
;
667 /* Load commands are variable-size: so read the command type and
668 size first and then read the rest. */
669 if (!unexec_read (&lc
, sizeof (struct load_command
)))
670 unexec_error ("cannot read load command");
671 lca
[i
] = (struct load_command
*) malloc (lc
.cmdsize
);
672 memcpy (lca
[i
], &lc
, sizeof (struct load_command
));
673 if (!unexec_read (lca
[i
] + 1, lc
.cmdsize
- sizeof (struct load_command
)))
674 unexec_error ("cannot read content of load command");
675 if (lc
.cmd
== LC_SEGMENT
)
677 struct segment_command
*scp
= (struct segment_command
*) lca
[i
];
679 if (scp
->vmaddr
+ scp
->vmsize
> infile_lc_highest_addr
)
680 infile_lc_highest_addr
= scp
->vmaddr
+ scp
->vmsize
;
682 if (strncmp (scp
->segname
, SEG_TEXT
, 16) == 0)
684 struct section
*sectp
= (struct section
*) (scp
+ 1);
687 for (j
= 0; j
< scp
->nsects
; j
++)
688 if (sectp
->offset
< text_seg_lowest_offset
)
689 text_seg_lowest_offset
= sectp
->offset
;
694 printf ("Highest address of load commands in input file: %#8lx\n",
695 (unsigned long)infile_lc_highest_addr
);
697 printf ("Lowest offset of all sections in __TEXT segment: %#8lx\n",
698 text_seg_lowest_offset
);
700 printf ("--- List of Load Commands in Input File ---\n");
701 printf ("# cmd cmdsize name address size\n");
703 for (i
= 0; i
< nlc
; i
++)
706 print_load_command (lca
[i
]);
710 /* Copy a LC_SEGMENT load command other than the __DATA segment from
711 the input file to the output file, adjusting the file offset of the
712 segment and the file offsets of sections contained in it. */
714 copy_segment (struct load_command
*lc
)
716 struct segment_command
*scp
= (struct segment_command
*) lc
;
717 unsigned long old_fileoff
= scp
->fileoff
;
718 struct section
*sectp
;
721 scp
->fileoff
= curr_file_offset
;
723 sectp
= (struct section
*) (scp
+ 1);
724 for (j
= 0; j
< scp
->nsects
; j
++)
726 sectp
->offset
+= curr_file_offset
- old_fileoff
;
730 printf ("Writing segment %-16.16s @ %#8lx (%#8lx/%#8lx @ %#10lx)\n",
731 scp
->segname
, (long) (scp
->fileoff
), (long) (scp
->filesize
),
732 (long) (scp
->vmsize
), (long) (scp
->vmaddr
));
734 if (!unexec_copy (scp
->fileoff
, old_fileoff
, scp
->filesize
))
735 unexec_error ("cannot copy segment from input to output file");
736 curr_file_offset
+= ROUNDUP_TO_PAGE_BOUNDARY (scp
->filesize
);
738 if (!unexec_write (curr_header_offset
, lc
, lc
->cmdsize
))
739 unexec_error ("cannot write load command to header");
741 curr_header_offset
+= lc
->cmdsize
;
744 /* Copy a LC_SEGMENT load command for the __DATA segment in the input
745 file to the output file. We assume that only one such segment load
746 command exists in the input file and it contains the sections
747 __data, __bss, __common, __la_symbol_ptr, __nl_symbol_ptr, and
748 __dyld. The first three of these should be dumped from memory and
749 the rest should be copied from the input file. Note that the
750 sections __bss and __common contain no data in the input file
751 because their flag fields have the value S_ZEROFILL. Dumping these
752 from memory makes it necessary to adjust file offset fields in
753 subsequently dumped load commands. Then, create new __DATA segment
754 load commands for regions on the region list other than the one
755 corresponding to the __DATA segment in the input file. */
757 copy_data_segment (struct load_command
*lc
)
759 struct segment_command
*scp
= (struct segment_command
*) lc
;
760 struct section
*sectp
;
762 unsigned long header_offset
, old_file_offset
;
764 /* The new filesize of the segment is set to its vmsize because data
765 blocks for segments must start at region boundaries. Note that
766 this may leave unused locations at the end of the segment data
767 block because the total of the sizes of all sections in the
768 segment is generally smaller than vmsize. */
769 scp
->filesize
= scp
->vmsize
;
771 printf ("Writing segment %-16.16s @ %#8lx (%#8lx/%#8lx @ %#10lx)\n",
772 scp
->segname
, curr_file_offset
, (long)(scp
->filesize
),
773 (long)(scp
->vmsize
), (long) (scp
->vmaddr
));
775 /* Offsets in the output file for writing the next section structure
776 and segment data block, respectively. */
777 header_offset
= curr_header_offset
+ sizeof (struct segment_command
);
779 sectp
= (struct section
*) (scp
+ 1);
780 for (j
= 0; j
< scp
->nsects
; j
++)
782 old_file_offset
= sectp
->offset
;
783 sectp
->offset
= sectp
->addr
- scp
->vmaddr
+ curr_file_offset
;
784 /* The __data section is dumped from memory. The __bss and
785 __common sections are also dumped from memory but their flag
786 fields require changing (from S_ZEROFILL to S_REGULAR). The
787 other three kinds of sections are just copied from the input
789 if (strncmp (sectp
->sectname
, SECT_DATA
, 16) == 0)
791 if (!unexec_write (sectp
->offset
, (void *) sectp
->addr
, sectp
->size
))
792 unexec_error ("cannot write section %s", SECT_DATA
);
793 if (!unexec_write (header_offset
, sectp
, sizeof (struct section
)))
794 unexec_error ("cannot write section %s's header", SECT_DATA
);
796 else if (strncmp (sectp
->sectname
, SECT_COMMON
, 16) == 0)
798 sectp
->flags
= S_REGULAR
;
799 if (!unexec_write (sectp
->offset
, (void *) sectp
->addr
, sectp
->size
))
800 unexec_error ("cannot write section %s", sectp
->sectname
);
801 if (!unexec_write (header_offset
, sectp
, sizeof (struct section
)))
802 unexec_error ("cannot write section %s's header", sectp
->sectname
);
804 else if (strncmp (sectp
->sectname
, SECT_BSS
, 16) == 0)
806 extern char *my_endbss_static
;
807 unsigned long my_size
;
809 sectp
->flags
= S_REGULAR
;
811 /* Clear uninitialized local variables in statically linked
812 libraries. In particular, function pointers stored by
813 libSystemStub.a, which is introduced in Mac OS X 10.4 for
814 binary compatibility with respect to long double, are
815 cleared so that they will be reinitialized when the
816 dumped binary is executed on other versions of OS. */
817 my_size
= (unsigned long)my_endbss_static
- sectp
->addr
;
818 if (!(sectp
->addr
<= (unsigned long)my_endbss_static
819 && my_size
<= sectp
->size
))
820 unexec_error ("my_endbss_static is not in section %s",
822 if (!unexec_write (sectp
->offset
, (void *) sectp
->addr
, my_size
))
823 unexec_error ("cannot write section %s", sectp
->sectname
);
824 if (!unexec_write_zero (sectp
->offset
+ my_size
,
825 sectp
->size
- my_size
))
826 unexec_error ("cannot write section %s", sectp
->sectname
);
827 if (!unexec_write (header_offset
, sectp
, sizeof (struct section
)))
828 unexec_error ("cannot write section %s's header", sectp
->sectname
);
830 else if (strncmp (sectp
->sectname
, "__la_symbol_ptr", 16) == 0
831 || strncmp (sectp
->sectname
, "__nl_symbol_ptr", 16) == 0
832 || strncmp (sectp
->sectname
, "__la_sym_ptr2", 16) == 0
833 || strncmp (sectp
->sectname
, "__dyld", 16) == 0
834 || strncmp (sectp
->sectname
, "__const", 16) == 0
835 || strncmp (sectp
->sectname
, "__cfstring", 16) == 0
836 || strncmp (sectp
->sectname
, "__gcc_except_tab", 16) == 0
837 || strncmp (sectp
->sectname
, "__program_vars", 16) == 0
838 || strncmp (sectp
->sectname
, "__objc_", 7) == 0)
840 if (!unexec_copy (sectp
->offset
, old_file_offset
, sectp
->size
))
841 unexec_error ("cannot copy section %s", sectp
->sectname
);
842 if (!unexec_write (header_offset
, sectp
, sizeof (struct section
)))
843 unexec_error ("cannot write section %s's header", sectp
->sectname
);
846 unexec_error ("unrecognized section name in __DATA segment");
848 printf (" section %-16.16s at %#8lx - %#8lx (sz: %#8lx)\n",
849 sectp
->sectname
, (long) (sectp
->offset
),
850 (long) (sectp
->offset
+ sectp
->size
), (long) (sectp
->size
));
852 header_offset
+= sizeof (struct section
);
856 curr_file_offset
+= ROUNDUP_TO_PAGE_BOUNDARY (scp
->filesize
);
858 if (!unexec_write (curr_header_offset
, scp
, sizeof (struct segment_command
)))
859 unexec_error ("cannot write header of __DATA segment");
860 curr_header_offset
+= lc
->cmdsize
;
862 /* Create new __DATA segment load commands for regions on the region
863 list that do not corresponding to any segment load commands in
866 for (j
= 0; j
< num_unexec_regions
; j
++)
868 struct segment_command sc
;
871 sc
.cmdsize
= sizeof (struct segment_command
);
872 strncpy (sc
.segname
, SEG_DATA
, 16);
873 sc
.vmaddr
= unexec_regions
[j
].range
.address
;
874 sc
.vmsize
= unexec_regions
[j
].range
.size
;
875 sc
.fileoff
= curr_file_offset
;
876 sc
.filesize
= unexec_regions
[j
].filesize
;
877 sc
.maxprot
= VM_PROT_READ
| VM_PROT_WRITE
;
878 sc
.initprot
= VM_PROT_READ
| VM_PROT_WRITE
;
882 printf ("Writing segment %-16.16s @ %#8lx (%#8lx/%#8lx @ %#10lx)\n",
883 sc
.segname
, (long) (sc
.fileoff
), (long) (sc
.filesize
),
884 (long) (sc
.vmsize
), (long) (sc
.vmaddr
));
886 if (!unexec_write (sc
.fileoff
, (void *) sc
.vmaddr
, sc
.filesize
))
887 unexec_error ("cannot write new __DATA segment");
888 curr_file_offset
+= ROUNDUP_TO_PAGE_BOUNDARY (sc
.filesize
);
890 if (!unexec_write (curr_header_offset
, &sc
, sc
.cmdsize
))
891 unexec_error ("cannot write new __DATA segment's header");
892 curr_header_offset
+= sc
.cmdsize
;
897 /* Copy a LC_SYMTAB load command from the input file to the output
898 file, adjusting the file offset fields. */
900 copy_symtab (struct load_command
*lc
, long delta
)
902 struct symtab_command
*stp
= (struct symtab_command
*) lc
;
904 stp
->symoff
+= delta
;
905 stp
->stroff
+= delta
;
907 printf ("Writing LC_SYMTAB command\n");
909 if (!unexec_write (curr_header_offset
, lc
, lc
->cmdsize
))
910 unexec_error ("cannot write symtab command to header");
912 curr_header_offset
+= lc
->cmdsize
;
915 /* Fix up relocation entries. */
917 unrelocate (const char *name
, off_t reloff
, int nrel
, vm_address_t base
)
919 int i
, unreloc_count
;
920 struct relocation_info reloc_info
;
921 struct scattered_relocation_info
*sc_reloc_info
922 = (struct scattered_relocation_info
*) &reloc_info
;
923 vm_address_t location
;
925 for (unreloc_count
= 0, i
= 0; i
< nrel
; i
++)
927 if (lseek (infd
, reloff
, L_SET
) != reloff
)
928 unexec_error ("unrelocate: %s:%d cannot seek to reloc_info", name
, i
);
929 if (!unexec_read (&reloc_info
, sizeof (reloc_info
)))
930 unexec_error ("unrelocate: %s:%d cannot read reloc_info", name
, i
);
931 reloff
+= sizeof (reloc_info
);
933 if (sc_reloc_info
->r_scattered
== 0)
934 switch (reloc_info
.r_type
)
936 case GENERIC_RELOC_VANILLA
:
937 location
= base
+ reloc_info
.r_address
;
938 if (location
>= data_segment_scp
->vmaddr
939 && location
< (data_segment_scp
->vmaddr
940 + data_segment_scp
->vmsize
))
942 off_t src_off
= data_segment_old_fileoff
943 + (location
- data_segment_scp
->vmaddr
);
944 off_t dst_off
= data_segment_scp
->fileoff
945 + (location
- data_segment_scp
->vmaddr
);
947 if (!unexec_copy (dst_off
, src_off
, 1 << reloc_info
.r_length
))
948 unexec_error ("unrelocate: %s:%d cannot copy original value",
954 unexec_error ("unrelocate: %s:%d cannot handle type = %d",
955 name
, i
, reloc_info
.r_type
);
958 switch (sc_reloc_info
->r_type
)
960 #if defined (__ppc__)
961 case PPC_RELOC_PB_LA_PTR
:
962 /* nothing to do for prebound lazy pointer */
966 unexec_error ("unrelocate: %s:%d cannot handle scattered type = %d",
967 name
, i
, sc_reloc_info
->r_type
);
972 printf ("Fixed up %d/%d %s relocation entries in data segment.\n",
973 unreloc_count
, nrel
, name
);
977 /* Rebase r_address in the relocation table. */
979 rebase_reloc_address (off_t reloff
, int nrel
, long linkedit_delta
, long diff
)
982 struct relocation_info reloc_info
;
983 struct scattered_relocation_info
*sc_reloc_info
984 = (struct scattered_relocation_info
*) &reloc_info
;
986 for (i
= 0; i
< nrel
; i
++, reloff
+= sizeof (reloc_info
))
988 if (lseek (infd
, reloff
- linkedit_delta
, L_SET
)
989 != reloff
- linkedit_delta
)
990 unexec_error ("rebase_reloc_table: cannot seek to reloc_info");
991 if (!unexec_read (&reloc_info
, sizeof (reloc_info
)))
992 unexec_error ("rebase_reloc_table: cannot read reloc_info");
994 if (sc_reloc_info
->r_scattered
== 0
995 && reloc_info
.r_type
== GENERIC_RELOC_VANILLA
)
997 reloc_info
.r_address
-= diff
;
998 if (!unexec_write (reloff
, &reloc_info
, sizeof (reloc_info
)))
999 unexec_error ("rebase_reloc_table: cannot write reloc_info");
1005 /* Copy a LC_DYSYMTAB load command from the input file to the output
1006 file, adjusting the file offset fields. */
1008 copy_dysymtab (struct load_command
*lc
, long delta
)
1010 struct dysymtab_command
*dstp
= (struct dysymtab_command
*) lc
;
1019 for (i
= 0; i
< nlc
; i
++)
1020 if (lca
[i
]->cmd
== LC_SEGMENT
)
1022 struct segment_command
*scp
= (struct segment_command
*) lca
[i
];
1024 if (scp
->vmaddr
+ scp
->vmsize
> 0x100000000
1025 && (scp
->initprot
& VM_PROT_WRITE
) != 0)
1027 base
= data_segment_scp
->vmaddr
;
1033 /* First writable segment address. */
1034 base
= data_segment_scp
->vmaddr
;
1037 /* First segment address in the file (unless MH_SPLIT_SEGS set). */
1041 unrelocate ("local", dstp
->locreloff
, dstp
->nlocrel
, base
);
1042 unrelocate ("external", dstp
->extreloff
, dstp
->nextrel
, base
);
1044 if (dstp
->nextrel
> 0) {
1045 dstp
->extreloff
+= delta
;
1048 if (dstp
->nlocrel
> 0) {
1049 dstp
->locreloff
+= delta
;
1052 if (dstp
->nindirectsyms
> 0)
1053 dstp
->indirectsymoff
+= delta
;
1055 printf ("Writing LC_DYSYMTAB command\n");
1057 if (!unexec_write (curr_header_offset
, lc
, lc
->cmdsize
))
1058 unexec_error ("cannot write symtab command to header");
1060 curr_header_offset
+= lc
->cmdsize
;
1063 /* Check if the relocation base needs to be changed. */
1066 vm_address_t newbase
= 0;
1069 for (i
= 0; i
< num_unexec_regions
; i
++)
1070 if (unexec_regions
[i
].range
.address
+ unexec_regions
[i
].range
.size
1073 newbase
= data_segment_scp
->vmaddr
;
1079 rebase_reloc_address (dstp
->locreloff
, dstp
->nlocrel
, delta
, newbase
);
1080 rebase_reloc_address (dstp
->extreloff
, dstp
->nextrel
, delta
, newbase
);
1086 /* Copy a LC_TWOLEVEL_HINTS load command from the input file to the output
1087 file, adjusting the file offset fields. */
1089 copy_twolevelhints (struct load_command
*lc
, long delta
)
1091 struct twolevel_hints_command
*tlhp
= (struct twolevel_hints_command
*) lc
;
1093 if (tlhp
->nhints
> 0) {
1094 tlhp
->offset
+= delta
;
1097 printf ("Writing LC_TWOLEVEL_HINTS command\n");
1099 if (!unexec_write (curr_header_offset
, lc
, lc
->cmdsize
))
1100 unexec_error ("cannot write two level hint command to header");
1102 curr_header_offset
+= lc
->cmdsize
;
1106 /* Copy a LC_DYLD_INFO(_ONLY) load command from the input file to the output
1107 file, adjusting the file offset fields. */
1109 copy_dyld_info (struct load_command
*lc
, long delta
)
1111 struct dyld_info_command
*dip
= (struct dyld_info_command
*) lc
;
1113 if (dip
->rebase_off
> 0)
1114 dip
->rebase_off
+= delta
;
1115 if (dip
->bind_off
> 0)
1116 dip
->bind_off
+= delta
;
1117 if (dip
->weak_bind_off
> 0)
1118 dip
->weak_bind_off
+= delta
;
1119 if (dip
->lazy_bind_off
> 0)
1120 dip
->lazy_bind_off
+= delta
;
1121 if (dip
->export_off
> 0)
1122 dip
->export_off
+= delta
;
1124 printf ("Writing ");
1125 print_load_command_name (lc
->cmd
);
1126 printf (" command\n");
1128 if (!unexec_write (curr_header_offset
, lc
, lc
->cmdsize
))
1129 unexec_error ("cannot write dyld info command to header");
1131 curr_header_offset
+= lc
->cmdsize
;
1135 /* Copy other kinds of load commands from the input file to the output
1136 file, ones that do not require adjustments of file offsets. */
1138 copy_other (struct load_command
*lc
)
1140 printf ("Writing ");
1141 print_load_command_name (lc
->cmd
);
1142 printf (" command\n");
1144 if (!unexec_write (curr_header_offset
, lc
, lc
->cmdsize
))
1145 unexec_error ("cannot write symtab command to header");
1147 curr_header_offset
+= lc
->cmdsize
;
1150 /* Loop through all load commands and dump them. Then write the Mach
1156 long linkedit_delta
= 0;
1158 printf ("--- Load Commands written to Output File ---\n");
1160 for (i
= 0; i
< nlc
; i
++)
1161 switch (lca
[i
]->cmd
)
1165 struct segment_command
*scp
= (struct segment_command
*) lca
[i
];
1166 if (strncmp (scp
->segname
, SEG_DATA
, 16) == 0)
1168 /* save data segment file offset and segment_command for
1170 if (data_segment_old_fileoff
)
1171 unexec_error ("cannot handle multiple DATA segments"
1173 data_segment_old_fileoff
= scp
->fileoff
;
1174 data_segment_scp
= scp
;
1176 copy_data_segment (lca
[i
]);
1180 if (strncmp (scp
->segname
, SEG_LINKEDIT
, 16) == 0)
1183 unexec_error ("cannot handle multiple LINKEDIT segments"
1185 linkedit_delta
= curr_file_offset
- scp
->fileoff
;
1188 copy_segment (lca
[i
]);
1193 copy_symtab (lca
[i
], linkedit_delta
);
1196 copy_dysymtab (lca
[i
], linkedit_delta
);
1198 case LC_TWOLEVEL_HINTS
:
1199 copy_twolevelhints (lca
[i
], linkedit_delta
);
1203 case LC_DYLD_INFO_ONLY
:
1204 copy_dyld_info (lca
[i
], linkedit_delta
);
1208 copy_other (lca
[i
]);
1212 if (curr_header_offset
> text_seg_lowest_offset
)
1213 unexec_error ("not enough room for load commands for new __DATA segments");
1215 printf ("%ld unused bytes follow Mach-O header\n",
1216 text_seg_lowest_offset
- curr_header_offset
);
1218 mh
.sizeofcmds
= curr_header_offset
- sizeof (struct mach_header
);
1219 if (!unexec_write (0, &mh
, sizeof (struct mach_header
)))
1220 unexec_error ("cannot write final header contents");
1223 /* Take a snapshot of Emacs and make a Mach-O format executable file
1224 from it. The file names of the output and input files are outfile
1225 and infile, respectively. The three other parameters are
1228 unexec (const char *outfile
, const char *infile
)
1231 unexec_error ("Unexec from a dumped executable is not supported.");
1233 pagesize
= getpagesize ();
1234 infd
= open (infile
, O_RDONLY
, 0);
1237 unexec_error ("cannot open input file `%s'", infile
);
1240 outfd
= open (outfile
, O_WRONLY
| O_TRUNC
| O_CREAT
, 0755);
1244 unexec_error ("cannot open output file `%s'", outfile
);
1247 build_region_list ();
1248 read_load_commands ();
1250 find_emacs_zone_regions ();
1251 unexec_regions_merge ();
1263 unexec_init_emacs_zone (void)
1265 emacs_zone
= malloc_create_zone (0, 0);
1266 malloc_set_zone_name (emacs_zone
, "EmacsZone");
1269 #ifndef MACOSX_MALLOC_MULT16
1270 #define MACOSX_MALLOC_MULT16 1
1273 typedef struct unexec_malloc_header
{
1278 } unexec_malloc_header_t
;
1280 #if MACOSX_MALLOC_MULT16
1282 #define ptr_in_unexec_regions(p) ((((vm_address_t) (p)) & 8) != 0)
1287 ptr_in_unexec_regions (void *ptr
)
1291 for (i
= 0; i
< num_unexec_regions
; i
++)
1292 if ((vm_address_t
) ptr
- unexec_regions
[i
].range
.address
1293 < unexec_regions
[i
].range
.size
)
1302 unexec_malloc (size_t size
)
1309 #if MACOSX_MALLOC_MULT16
1310 assert (((vm_address_t
) p
% 16) == 0);
1316 unexec_malloc_header_t
*ptr
;
1318 ptr
= (unexec_malloc_header_t
*)
1319 malloc_zone_malloc (emacs_zone
, size
+ sizeof (unexec_malloc_header_t
));
1322 #if MACOSX_MALLOC_MULT16
1323 assert (((vm_address_t
) ptr
% 16) == 8);
1325 return (void *) ptr
;
1330 unexec_realloc (void *old_ptr
, size_t new_size
)
1336 if (ptr_in_unexec_regions (old_ptr
))
1338 size_t old_size
= ((unexec_malloc_header_t
*) old_ptr
)[-1].u
.size
;
1339 size_t size
= new_size
> old_size
? old_size
: new_size
;
1341 p
= (size_t *) malloc (new_size
);
1343 memcpy (p
, old_ptr
, size
);
1347 p
= realloc (old_ptr
, new_size
);
1349 #if MACOSX_MALLOC_MULT16
1350 assert (((vm_address_t
) p
% 16) == 0);
1356 unexec_malloc_header_t
*ptr
;
1358 ptr
= (unexec_malloc_header_t
*)
1359 malloc_zone_realloc (emacs_zone
, (unexec_malloc_header_t
*) old_ptr
- 1,
1360 new_size
+ sizeof (unexec_malloc_header_t
));
1361 ptr
->u
.size
= new_size
;
1363 #if MACOSX_MALLOC_MULT16
1364 assert (((vm_address_t
) ptr
% 16) == 8);
1366 return (void *) ptr
;
1371 unexec_free (void *ptr
)
1377 if (!ptr_in_unexec_regions (ptr
))
1381 malloc_zone_free (emacs_zone
, (unexec_malloc_header_t
*) ptr
- 1);