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, 2012 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.
93 #include <sys/types.h>
95 #include <mach/mach.h>
96 #include <mach-o/loader.h>
97 #include <mach-o/reloc.h>
99 #include <mach-o/ppc/reloc.h>
105 #ifdef HAVE_MALLOC_MALLOC_H
106 #include <malloc/malloc.h>
108 #include <objc/malloc.h>
114 #define mach_header mach_header_64
115 #define segment_command segment_command_64
116 #undef VM_REGION_BASIC_INFO_COUNT
117 #define VM_REGION_BASIC_INFO_COUNT VM_REGION_BASIC_INFO_COUNT_64
118 #undef VM_REGION_BASIC_INFO
119 #define VM_REGION_BASIC_INFO VM_REGION_BASIC_INFO_64
121 #define LC_SEGMENT LC_SEGMENT_64
122 #define vm_region vm_region_64
123 #define section section_64
125 #define MH_MAGIC MH_MAGIC_64
130 /* Size of buffer used to copy data from the input file to the output
131 file in function unexec_copy. */
132 #define UNEXEC_COPY_BUFSZ 1024
134 /* Regions with memory addresses above this value are assumed to be
135 mapped to dynamically loaded libraries and will not be dumped. */
136 #define VM_DATA_TOP (20 * 1024 * 1024)
138 /* Type of an element on the list of regions to be dumped. */
140 vm_address_t address
;
142 vm_prot_t protection
;
143 vm_prot_t max_protection
;
145 struct region_t
*next
;
148 /* Head and tail of the list of regions to be dumped. */
149 static struct region_t
*region_list_head
= 0;
150 static struct region_t
*region_list_tail
= 0;
152 /* Pointer to array of load commands. */
153 static struct load_command
**lca
;
155 /* Number of load commands. */
158 /* The highest VM address of segments loaded by the input file.
159 Regions with addresses beyond this are assumed to be allocated
160 dynamically and thus require dumping. */
161 static vm_address_t infile_lc_highest_addr
= 0;
163 /* The lowest file offset used by the all sections in the __TEXT
164 segments. This leaves room at the beginning of the file to store
165 the Mach-O header. Check this value against header size to ensure
166 the added load commands for the new __DATA segments did not
167 overwrite any of the sections in the __TEXT segment. */
168 static unsigned long text_seg_lowest_offset
= 0x10000000;
171 static struct mach_header mh
;
173 /* Offset at which the next load command should be written. */
174 static unsigned long curr_header_offset
= sizeof (struct mach_header
);
176 /* Offset at which the next segment should be written. */
177 static unsigned long curr_file_offset
= 0;
179 static unsigned long pagesize
;
180 #define ROUNDUP_TO_PAGE_BOUNDARY(x) (((x) + pagesize - 1) & ~(pagesize - 1))
182 static int infd
, outfd
;
184 static int in_dumped_exec
= 0;
186 static malloc_zone_t
*emacs_zone
;
188 /* file offset of input file's data segment */
189 static off_t data_segment_old_fileoff
= 0;
191 static struct segment_command
*data_segment_scp
;
193 /* Read N bytes from infd into memory starting at address DEST.
194 Return true if successful, false otherwise. */
196 unexec_read (void *dest
, size_t n
)
198 return n
== read (infd
, dest
, n
);
201 /* Write COUNT bytes from memory starting at address SRC to outfd
202 starting at offset DEST. Return true if successful, false
205 unexec_write (off_t dest
, const void *src
, size_t count
)
207 if (lseek (outfd
, dest
, SEEK_SET
) != dest
)
210 return write (outfd
, src
, count
) == count
;
213 /* Write COUNT bytes of zeros to outfd starting at offset DEST.
214 Return true if successful, false otherwise. */
216 unexec_write_zero (off_t dest
, size_t count
)
218 char buf
[UNEXEC_COPY_BUFSZ
];
221 bzero (buf
, UNEXEC_COPY_BUFSZ
);
222 if (lseek (outfd
, dest
, SEEK_SET
) != dest
)
227 bytes
= count
> UNEXEC_COPY_BUFSZ
? UNEXEC_COPY_BUFSZ
: count
;
228 if (write (outfd
, buf
, bytes
) != bytes
)
236 /* Copy COUNT bytes from starting offset SRC in infd to starting
237 offset DEST in outfd. Return true if successful, false
240 unexec_copy (off_t dest
, off_t src
, ssize_t count
)
243 ssize_t bytes_to_read
;
245 char buf
[UNEXEC_COPY_BUFSZ
];
247 if (lseek (infd
, src
, SEEK_SET
) != src
)
250 if (lseek (outfd
, dest
, SEEK_SET
) != dest
)
255 bytes_to_read
= count
> UNEXEC_COPY_BUFSZ
? UNEXEC_COPY_BUFSZ
: count
;
256 bytes_read
= read (infd
, buf
, bytes_to_read
);
259 if (write (outfd
, buf
, bytes_read
) != bytes_read
)
267 /* Debugging and informational messages routines. */
270 unexec_error (char *format
, ...)
274 va_start (ap
, format
);
275 fprintf (stderr
, "unexec: ");
276 vfprintf (stderr
, format
, ap
);
277 fprintf (stderr
, "\n");
283 print_prot (vm_prot_t prot
)
285 if (prot
== VM_PROT_NONE
)
289 putchar (prot
& VM_PROT_READ
? 'r' : ' ');
290 putchar (prot
& VM_PROT_WRITE
? 'w' : ' ');
291 putchar (prot
& VM_PROT_EXECUTE
? 'x' : ' ');
297 print_region (vm_address_t address
, vm_size_t size
, vm_prot_t prot
,
300 printf ("%#10lx %#8lx ", (long) address
, (long) size
);
303 print_prot (max_prot
);
312 printf (" address size prot maxp\n");
314 for (r
= region_list_head
; r
; r
= r
->next
)
315 print_region (r
->address
, r
->size
, r
->protection
, r
->max_protection
);
321 task_t target_task
= mach_task_self ();
322 vm_address_t address
= (vm_address_t
) 0;
324 struct vm_region_basic_info info
;
325 mach_msg_type_number_t info_count
= VM_REGION_BASIC_INFO_COUNT
;
326 mach_port_t object_name
;
328 printf (" address size prot maxp\n");
330 while (vm_region (target_task
, &address
, &size
, VM_REGION_BASIC_INFO
,
331 (vm_region_info_t
) &info
, &info_count
, &object_name
)
332 == KERN_SUCCESS
&& info_count
== VM_REGION_BASIC_INFO_COUNT
)
334 print_region (address
, size
, info
.protection
, info
.max_protection
);
336 if (object_name
!= MACH_PORT_NULL
)
337 mach_port_deallocate (target_task
, object_name
);
343 /* Build the list of regions that need to be dumped. Regions with
344 addresses above VM_DATA_TOP are omitted. Adjacent regions with
345 identical protection are merged. Note that non-writable regions
346 cannot be omitted because they some regions created at run time are
351 task_t target_task
= mach_task_self ();
352 vm_address_t address
= (vm_address_t
) 0;
354 struct vm_region_basic_info info
;
355 mach_msg_type_number_t info_count
= VM_REGION_BASIC_INFO_COUNT
;
356 mach_port_t object_name
;
360 printf ("--- List of All Regions ---\n");
361 printf (" address size prot maxp\n");
364 while (vm_region (target_task
, &address
, &size
, VM_REGION_BASIC_INFO
,
365 (vm_region_info_t
) &info
, &info_count
, &object_name
)
366 == KERN_SUCCESS
&& info_count
== VM_REGION_BASIC_INFO_COUNT
)
368 /* Done when we reach addresses of shared libraries, which are
369 loaded in high memory. */
370 if (address
>= VM_DATA_TOP
)
374 print_region (address
, size
, info
.protection
, info
.max_protection
);
377 /* If a region immediately follows the previous one (the one
378 most recently added to the list) and has identical
379 protection, merge it with the latter. Otherwise create a
380 new list element for it. */
382 && info
.protection
== region_list_tail
->protection
383 && info
.max_protection
== region_list_tail
->max_protection
384 && region_list_tail
->address
+ region_list_tail
->size
== address
)
386 region_list_tail
->size
+= size
;
390 r
= (struct region_t
*) malloc (sizeof (struct region_t
));
393 unexec_error ("cannot allocate region structure");
395 r
->address
= address
;
397 r
->protection
= info
.protection
;
398 r
->max_protection
= info
.max_protection
;
401 if (region_list_head
== 0)
403 region_list_head
= r
;
404 region_list_tail
= r
;
408 region_list_tail
->next
= r
;
409 region_list_tail
= r
;
412 /* Deallocate (unused) object name returned by
414 if (object_name
!= MACH_PORT_NULL
)
415 mach_port_deallocate (target_task
, object_name
);
421 printf ("--- List of Regions to be Dumped ---\n");
422 print_region_list ();
426 #define MAX_UNEXEC_REGIONS 400
428 static int num_unexec_regions
;
432 } unexec_region_info
;
433 static unexec_region_info unexec_regions
[MAX_UNEXEC_REGIONS
];
436 unexec_regions_recorder (task_t task
, void *rr
, unsigned type
,
437 vm_range_t
*ranges
, unsigned num
)
442 while (num
&& num_unexec_regions
< MAX_UNEXEC_REGIONS
)
444 /* Subtract the size of trailing null bytes from filesize. It
445 can be smaller than vmsize in segment commands. In such a
446 case, trailing bytes are initialized with zeros. */
447 for (p
= ranges
->address
+ ranges
->size
; p
> ranges
->address
; p
--)
448 if (*(((char *) p
)-1))
450 filesize
= p
- ranges
->address
;
452 unexec_regions
[num_unexec_regions
].filesize
= filesize
;
453 unexec_regions
[num_unexec_regions
++].range
= *ranges
;
454 printf ("%#10lx (sz: %#8lx/%#8lx)\n", (long) (ranges
->address
),
455 (long) filesize
, (long) (ranges
->size
));
461 unexec_reader (task_t task
, vm_address_t address
, vm_size_t size
, void **ptr
)
463 *ptr
= (void *) address
;
468 find_emacs_zone_regions ()
470 num_unexec_regions
= 0;
472 emacs_zone
->introspect
->enumerator (mach_task_self(), 0,
473 MALLOC_PTR_REGION_RANGE_TYPE
474 | MALLOC_ADMIN_REGION_RANGE_TYPE
,
475 (vm_address_t
) emacs_zone
,
477 unexec_regions_recorder
);
479 if (num_unexec_regions
== MAX_UNEXEC_REGIONS
)
480 unexec_error ("find_emacs_zone_regions: too many regions");
484 unexec_regions_sort_compare (const void *a
, const void *b
)
486 vm_address_t aa
= ((unexec_region_info
*) a
)->range
.address
;
487 vm_address_t bb
= ((unexec_region_info
*) b
)->range
.address
;
498 unexec_regions_merge ()
501 unexec_region_info r
;
504 qsort (unexec_regions
, num_unexec_regions
, sizeof (unexec_regions
[0]),
505 &unexec_regions_sort_compare
);
507 r
= unexec_regions
[0];
508 padsize
= r
.range
.address
& (pagesize
- 1);
511 r
.range
.address
-= padsize
;
512 r
.range
.size
+= padsize
;
513 r
.filesize
+= padsize
;
515 for (i
= 1; i
< num_unexec_regions
; i
++)
517 if (r
.range
.address
+ r
.range
.size
== unexec_regions
[i
].range
.address
518 && r
.range
.size
- r
.filesize
< 2 * pagesize
)
520 r
.filesize
= r
.range
.size
+ unexec_regions
[i
].filesize
;
521 r
.range
.size
+= unexec_regions
[i
].range
.size
;
525 unexec_regions
[n
++] = r
;
526 r
= unexec_regions
[i
];
527 padsize
= r
.range
.address
& (pagesize
- 1);
530 if ((unexec_regions
[n
-1].range
.address
531 + unexec_regions
[n
-1].range
.size
) == r
.range
.address
)
532 unexec_regions
[n
-1].range
.size
-= padsize
;
534 r
.range
.address
-= padsize
;
535 r
.range
.size
+= padsize
;
536 r
.filesize
+= padsize
;
540 unexec_regions
[n
++] = r
;
541 num_unexec_regions
= n
;
545 /* More informational messages routines. */
548 print_load_command_name (int lc
)
554 printf ("LC_SEGMENT ");
556 printf ("LC_SEGMENT_64 ");
559 case LC_LOAD_DYLINKER
:
560 printf ("LC_LOAD_DYLINKER ");
563 printf ("LC_LOAD_DYLIB ");
566 printf ("LC_SYMTAB ");
569 printf ("LC_DYSYMTAB ");
572 printf ("LC_UNIXTHREAD ");
574 case LC_PREBOUND_DYLIB
:
575 printf ("LC_PREBOUND_DYLIB");
577 case LC_TWOLEVEL_HINTS
:
578 printf ("LC_TWOLEVEL_HINTS");
587 printf ("LC_DYLD_INFO ");
589 case LC_DYLD_INFO_ONLY
:
590 printf ("LC_DYLD_INFO_ONLY");
593 #ifdef LC_VERSION_MIN_MACOSX
594 case LC_VERSION_MIN_MACOSX
:
595 printf ("LC_VERSION_MIN_MACOSX");
598 #ifdef LC_FUNCTION_STARTS
599 case LC_FUNCTION_STARTS
:
600 printf ("LC_FUNCTION_STARTS");
609 print_load_command (struct load_command
*lc
)
611 print_load_command_name (lc
->cmd
);
612 printf ("%8d", lc
->cmdsize
);
614 if (lc
->cmd
== LC_SEGMENT
)
616 struct segment_command
*scp
;
617 struct section
*sectp
;
620 scp
= (struct segment_command
*) lc
;
621 printf (" %-16.16s %#10lx %#8lx\n",
622 scp
->segname
, (long) (scp
->vmaddr
), (long) (scp
->vmsize
));
624 sectp
= (struct section
*) (scp
+ 1);
625 for (j
= 0; j
< scp
->nsects
; j
++)
627 printf (" %-16.16s %#10lx %#8lx\n",
628 sectp
->sectname
, (long) (sectp
->addr
), (long) (sectp
->size
));
636 /* Read header and load commands from input file. Store the latter in
637 the global array lca. Store the total number of load commands in
638 global variable nlc. */
640 read_load_commands ()
644 if (!unexec_read (&mh
, sizeof (struct mach_header
)))
645 unexec_error ("cannot read mach-o header");
647 if (mh
.magic
!= MH_MAGIC
)
648 unexec_error ("input file not in Mach-O format");
650 if (mh
.filetype
!= MH_EXECUTE
)
651 unexec_error ("input Mach-O file is not an executable object file");
654 printf ("--- Header Information ---\n");
655 printf ("Magic = 0x%08x\n", mh
.magic
);
656 printf ("CPUType = %d\n", mh
.cputype
);
657 printf ("CPUSubType = %d\n", mh
.cpusubtype
);
658 printf ("FileType = 0x%x\n", mh
.filetype
);
659 printf ("NCmds = %d\n", mh
.ncmds
);
660 printf ("SizeOfCmds = %d\n", mh
.sizeofcmds
);
661 printf ("Flags = 0x%08x\n", mh
.flags
);
665 lca
= (struct load_command
**) malloc (nlc
* sizeof (struct load_command
*));
667 for (i
= 0; i
< nlc
; i
++)
669 struct load_command lc
;
670 /* Load commands are variable-size: so read the command type and
671 size first and then read the rest. */
672 if (!unexec_read (&lc
, sizeof (struct load_command
)))
673 unexec_error ("cannot read load command");
674 lca
[i
] = (struct load_command
*) malloc (lc
.cmdsize
);
675 memcpy (lca
[i
], &lc
, sizeof (struct load_command
));
676 if (!unexec_read (lca
[i
] + 1, lc
.cmdsize
- sizeof (struct load_command
)))
677 unexec_error ("cannot read content of load command");
678 if (lc
.cmd
== LC_SEGMENT
)
680 struct segment_command
*scp
= (struct segment_command
*) lca
[i
];
682 if (scp
->vmaddr
+ scp
->vmsize
> infile_lc_highest_addr
)
683 infile_lc_highest_addr
= scp
->vmaddr
+ scp
->vmsize
;
685 if (strncmp (scp
->segname
, SEG_TEXT
, 16) == 0)
687 struct section
*sectp
= (struct section
*) (scp
+ 1);
690 for (j
= 0; j
< scp
->nsects
; j
++)
691 if (sectp
->offset
< text_seg_lowest_offset
)
692 text_seg_lowest_offset
= sectp
->offset
;
697 printf ("Highest address of load commands in input file: %#8x\n",
698 infile_lc_highest_addr
);
700 printf ("Lowest offset of all sections in __TEXT segment: %#8lx\n",
701 text_seg_lowest_offset
);
703 printf ("--- List of Load Commands in Input File ---\n");
704 printf ("# cmd cmdsize name address size\n");
706 for (i
= 0; i
< nlc
; i
++)
709 print_load_command (lca
[i
]);
713 /* Copy a LC_SEGMENT load command other than the __DATA segment from
714 the input file to the output file, adjusting the file offset of the
715 segment and the file offsets of sections contained in it. */
717 copy_segment (struct load_command
*lc
)
719 struct segment_command
*scp
= (struct segment_command
*) lc
;
720 unsigned long old_fileoff
= scp
->fileoff
;
721 struct section
*sectp
;
724 scp
->fileoff
= curr_file_offset
;
726 sectp
= (struct section
*) (scp
+ 1);
727 for (j
= 0; j
< scp
->nsects
; j
++)
729 sectp
->offset
+= curr_file_offset
- old_fileoff
;
733 printf ("Writing segment %-16.16s @ %#8lx (%#8lx/%#8lx @ %#10lx)\n",
734 scp
->segname
, (long) (scp
->fileoff
), (long) (scp
->filesize
),
735 (long) (scp
->vmsize
), (long) (scp
->vmaddr
));
737 if (!unexec_copy (scp
->fileoff
, old_fileoff
, scp
->filesize
))
738 unexec_error ("cannot copy segment from input to output file");
739 curr_file_offset
+= ROUNDUP_TO_PAGE_BOUNDARY (scp
->filesize
);
741 if (!unexec_write (curr_header_offset
, lc
, lc
->cmdsize
))
742 unexec_error ("cannot write load command to header");
744 curr_header_offset
+= lc
->cmdsize
;
747 /* Copy a LC_SEGMENT load command for the __DATA segment in the input
748 file to the output file. We assume that only one such segment load
749 command exists in the input file and it contains the sections
750 __data, __bss, __common, __la_symbol_ptr, __nl_symbol_ptr, and
751 __dyld. The first three of these should be dumped from memory and
752 the rest should be copied from the input file. Note that the
753 sections __bss and __common contain no data in the input file
754 because their flag fields have the value S_ZEROFILL. Dumping these
755 from memory makes it necessary to adjust file offset fields in
756 subsequently dumped load commands. Then, create new __DATA segment
757 load commands for regions on the region list other than the one
758 corresponding to the __DATA segment in the input file. */
760 copy_data_segment (struct load_command
*lc
)
762 struct segment_command
*scp
= (struct segment_command
*) lc
;
763 struct section
*sectp
;
765 unsigned long header_offset
, old_file_offset
;
767 /* The new filesize of the segment is set to its vmsize because data
768 blocks for segments must start at region boundaries. Note that
769 this may leave unused locations at the end of the segment data
770 block because the total of the sizes of all sections in the
771 segment is generally smaller than vmsize. */
772 scp
->filesize
= scp
->vmsize
;
774 printf ("Writing segment %-16.16s @ %#8lx (%#8lx/%#8lx @ %#10lx)\n",
775 scp
->segname
, curr_file_offset
, (long)(scp
->filesize
),
776 (long)(scp
->vmsize
), (long) (scp
->vmaddr
));
778 /* Offsets in the output file for writing the next section structure
779 and segment data block, respectively. */
780 header_offset
= curr_header_offset
+ sizeof (struct segment_command
);
782 sectp
= (struct section
*) (scp
+ 1);
783 for (j
= 0; j
< scp
->nsects
; j
++)
785 old_file_offset
= sectp
->offset
;
786 sectp
->offset
= sectp
->addr
- scp
->vmaddr
+ curr_file_offset
;
787 /* The __data section is dumped from memory. The __bss and
788 __common sections are also dumped from memory but their flag
789 fields require changing (from S_ZEROFILL to S_REGULAR). The
790 other three kinds of sections are just copied from the input
792 if (strncmp (sectp
->sectname
, SECT_DATA
, 16) == 0)
794 if (!unexec_write (sectp
->offset
, (void *) sectp
->addr
, sectp
->size
))
795 unexec_error ("cannot write section %s", SECT_DATA
);
796 if (!unexec_write (header_offset
, sectp
, sizeof (struct section
)))
797 unexec_error ("cannot write section %s's header", SECT_DATA
);
799 else if (strncmp (sectp
->sectname
, SECT_COMMON
, 16) == 0)
801 sectp
->flags
= S_REGULAR
;
802 if (!unexec_write (sectp
->offset
, (void *) sectp
->addr
, sectp
->size
))
803 unexec_error ("cannot write section %s", sectp
->sectname
);
804 if (!unexec_write (header_offset
, sectp
, sizeof (struct section
)))
805 unexec_error ("cannot write section %s's header", sectp
->sectname
);
807 else if (strncmp (sectp
->sectname
, SECT_BSS
, 16) == 0)
809 extern char *my_endbss_static
;
810 unsigned long my_size
;
812 sectp
->flags
= S_REGULAR
;
814 /* Clear uninitialized local variables in statically linked
815 libraries. In particular, function pointers stored by
816 libSystemStub.a, which is introduced in Mac OS X 10.4 for
817 binary compatibility with respect to long double, are
818 cleared so that they will be reinitialized when the
819 dumped binary is executed on other versions of OS. */
820 my_size
= (unsigned long)my_endbss_static
- sectp
->addr
;
821 if (!(sectp
->addr
<= (unsigned long)my_endbss_static
822 && my_size
<= sectp
->size
))
823 unexec_error ("my_endbss_static is not in section %s",
825 if (!unexec_write (sectp
->offset
, (void *) sectp
->addr
, my_size
))
826 unexec_error ("cannot write section %s", sectp
->sectname
);
827 if (!unexec_write_zero (sectp
->offset
+ my_size
,
828 sectp
->size
- my_size
))
829 unexec_error ("cannot write section %s", sectp
->sectname
);
830 if (!unexec_write (header_offset
, sectp
, sizeof (struct section
)))
831 unexec_error ("cannot write section %s's header", sectp
->sectname
);
833 else if (strncmp (sectp
->sectname
, "__la_symbol_ptr", 16) == 0
834 || strncmp (sectp
->sectname
, "__nl_symbol_ptr", 16) == 0
835 || strncmp (sectp
->sectname
, "__got", 16) == 0
836 || strncmp (sectp
->sectname
, "__la_sym_ptr2", 16) == 0
837 || strncmp (sectp
->sectname
, "__dyld", 16) == 0
838 || strncmp (sectp
->sectname
, "__const", 16) == 0
839 || strncmp (sectp
->sectname
, "__cfstring", 16) == 0
840 || strncmp (sectp
->sectname
, "__gcc_except_tab", 16) == 0
841 || strncmp (sectp
->sectname
, "__program_vars", 16) == 0
842 || strncmp (sectp
->sectname
, "__objc_", 7) == 0)
844 if (!unexec_copy (sectp
->offset
, old_file_offset
, sectp
->size
))
845 unexec_error ("cannot copy section %s", sectp
->sectname
);
846 if (!unexec_write (header_offset
, sectp
, sizeof (struct section
)))
847 unexec_error ("cannot write section %s's header", sectp
->sectname
);
850 unexec_error ("unrecognized section name in __DATA segment");
852 printf (" section %-16.16s at %#8lx - %#8lx (sz: %#8lx)\n",
853 sectp
->sectname
, (long) (sectp
->offset
),
854 (long) (sectp
->offset
+ sectp
->size
), (long) (sectp
->size
));
856 header_offset
+= sizeof (struct section
);
860 curr_file_offset
+= ROUNDUP_TO_PAGE_BOUNDARY (scp
->filesize
);
862 if (!unexec_write (curr_header_offset
, scp
, sizeof (struct segment_command
)))
863 unexec_error ("cannot write header of __DATA segment");
864 curr_header_offset
+= lc
->cmdsize
;
866 /* Create new __DATA segment load commands for regions on the region
867 list that do not corresponding to any segment load commands in
870 for (j
= 0; j
< num_unexec_regions
; j
++)
872 struct segment_command sc
;
875 sc
.cmdsize
= sizeof (struct segment_command
);
876 strncpy (sc
.segname
, SEG_DATA
, 16);
877 sc
.vmaddr
= unexec_regions
[j
].range
.address
;
878 sc
.vmsize
= unexec_regions
[j
].range
.size
;
879 sc
.fileoff
= curr_file_offset
;
880 sc
.filesize
= unexec_regions
[j
].filesize
;
881 sc
.maxprot
= VM_PROT_READ
| VM_PROT_WRITE
;
882 sc
.initprot
= VM_PROT_READ
| VM_PROT_WRITE
;
886 printf ("Writing segment %-16.16s @ %#8lx (%#8lx/%#8lx @ %#10lx)\n",
887 sc
.segname
, (long) (sc
.fileoff
), (long) (sc
.filesize
),
888 (long) (sc
.vmsize
), (long) (sc
.vmaddr
));
890 if (!unexec_write (sc
.fileoff
, (void *) sc
.vmaddr
, sc
.filesize
))
891 unexec_error ("cannot write new __DATA segment");
892 curr_file_offset
+= ROUNDUP_TO_PAGE_BOUNDARY (sc
.filesize
);
894 if (!unexec_write (curr_header_offset
, &sc
, sc
.cmdsize
))
895 unexec_error ("cannot write new __DATA segment's header");
896 curr_header_offset
+= sc
.cmdsize
;
901 /* Copy a LC_SYMTAB load command from the input file to the output
902 file, adjusting the file offset fields. */
904 copy_symtab (struct load_command
*lc
, long delta
)
906 struct symtab_command
*stp
= (struct symtab_command
*) lc
;
908 stp
->symoff
+= delta
;
909 stp
->stroff
+= delta
;
911 printf ("Writing LC_SYMTAB command\n");
913 if (!unexec_write (curr_header_offset
, lc
, lc
->cmdsize
))
914 unexec_error ("cannot write symtab command to header");
916 curr_header_offset
+= lc
->cmdsize
;
919 /* Fix up relocation entries. */
921 unrelocate (const char *name
, off_t reloff
, int nrel
, vm_address_t base
)
923 int i
, unreloc_count
;
924 struct relocation_info reloc_info
;
925 struct scattered_relocation_info
*sc_reloc_info
926 = (struct scattered_relocation_info
*) &reloc_info
;
927 vm_address_t location
;
929 for (unreloc_count
= 0, i
= 0; i
< nrel
; i
++)
931 if (lseek (infd
, reloff
, L_SET
) != reloff
)
932 unexec_error ("unrelocate: %s:%d cannot seek to reloc_info", name
, i
);
933 if (!unexec_read (&reloc_info
, sizeof (reloc_info
)))
934 unexec_error ("unrelocate: %s:%d cannot read reloc_info", name
, i
);
935 reloff
+= sizeof (reloc_info
);
937 if (sc_reloc_info
->r_scattered
== 0)
938 switch (reloc_info
.r_type
)
940 case GENERIC_RELOC_VANILLA
:
941 location
= base
+ reloc_info
.r_address
;
942 if (location
>= data_segment_scp
->vmaddr
943 && location
< (data_segment_scp
->vmaddr
944 + data_segment_scp
->vmsize
))
946 off_t src_off
= data_segment_old_fileoff
947 + (location
- data_segment_scp
->vmaddr
);
948 off_t dst_off
= data_segment_scp
->fileoff
949 + (location
- data_segment_scp
->vmaddr
);
951 if (!unexec_copy (dst_off
, src_off
, 1 << reloc_info
.r_length
))
952 unexec_error ("unrelocate: %s:%d cannot copy original value",
958 unexec_error ("unrelocate: %s:%d cannot handle type = %d",
959 name
, i
, reloc_info
.r_type
);
962 switch (sc_reloc_info
->r_type
)
964 #if defined (__ppc__)
965 case PPC_RELOC_PB_LA_PTR
:
966 /* nothing to do for prebound lazy pointer */
970 unexec_error ("unrelocate: %s:%d cannot handle scattered type = %d",
971 name
, i
, sc_reloc_info
->r_type
);
976 printf ("Fixed up %d/%d %s relocation entries in data segment.\n",
977 unreloc_count
, nrel
, name
);
981 /* Rebase r_address in the relocation table. */
983 rebase_reloc_address (off_t reloff
, int nrel
, long linkedit_delta
, long diff
)
986 struct relocation_info reloc_info
;
987 struct scattered_relocation_info
*sc_reloc_info
988 = (struct scattered_relocation_info
*) &reloc_info
;
990 for (i
= 0; i
< nrel
; i
++, reloff
+= sizeof (reloc_info
))
992 if (lseek (infd
, reloff
- linkedit_delta
, L_SET
)
993 != reloff
- linkedit_delta
)
994 unexec_error ("rebase_reloc_table: cannot seek to reloc_info");
995 if (!unexec_read (&reloc_info
, sizeof (reloc_info
)))
996 unexec_error ("rebase_reloc_table: cannot read reloc_info");
998 if (sc_reloc_info
->r_scattered
== 0
999 && reloc_info
.r_type
== GENERIC_RELOC_VANILLA
)
1001 reloc_info
.r_address
-= diff
;
1002 if (!unexec_write (reloff
, &reloc_info
, sizeof (reloc_info
)))
1003 unexec_error ("rebase_reloc_table: cannot write reloc_info");
1009 /* Copy a LC_DYSYMTAB load command from the input file to the output
1010 file, adjusting the file offset fields. */
1012 copy_dysymtab (struct load_command
*lc
, long delta
)
1014 struct dysymtab_command
*dstp
= (struct dysymtab_command
*) lc
;
1023 for (i
= 0; i
< nlc
; i
++)
1024 if (lca
[i
]->cmd
== LC_SEGMENT
)
1026 struct segment_command
*scp
= (struct segment_command
*) lca
[i
];
1028 if (scp
->vmaddr
+ scp
->vmsize
> 0x100000000
1029 && (scp
->initprot
& VM_PROT_WRITE
) != 0)
1031 base
= data_segment_scp
->vmaddr
;
1037 /* First writable segment address. */
1038 base
= data_segment_scp
->vmaddr
;
1041 /* First segment address in the file (unless MH_SPLIT_SEGS set). */
1045 unrelocate ("local", dstp
->locreloff
, dstp
->nlocrel
, base
);
1046 unrelocate ("external", dstp
->extreloff
, dstp
->nextrel
, base
);
1048 if (dstp
->nextrel
> 0) {
1049 dstp
->extreloff
+= delta
;
1052 if (dstp
->nlocrel
> 0) {
1053 dstp
->locreloff
+= delta
;
1056 if (dstp
->nindirectsyms
> 0)
1057 dstp
->indirectsymoff
+= delta
;
1059 printf ("Writing LC_DYSYMTAB command\n");
1061 if (!unexec_write (curr_header_offset
, lc
, lc
->cmdsize
))
1062 unexec_error ("cannot write symtab command to header");
1064 curr_header_offset
+= lc
->cmdsize
;
1067 /* Check if the relocation base needs to be changed. */
1070 vm_address_t newbase
= 0;
1073 for (i
= 0; i
< num_unexec_regions
; i
++)
1074 if (unexec_regions
[i
].range
.address
+ unexec_regions
[i
].range
.size
1077 newbase
= data_segment_scp
->vmaddr
;
1083 rebase_reloc_address (dstp
->locreloff
, dstp
->nlocrel
, delta
, newbase
);
1084 rebase_reloc_address (dstp
->extreloff
, dstp
->nextrel
, delta
, newbase
);
1090 /* Copy a LC_TWOLEVEL_HINTS load command from the input file to the output
1091 file, adjusting the file offset fields. */
1093 copy_twolevelhints (struct load_command
*lc
, long delta
)
1095 struct twolevel_hints_command
*tlhp
= (struct twolevel_hints_command
*) lc
;
1097 if (tlhp
->nhints
> 0) {
1098 tlhp
->offset
+= delta
;
1101 printf ("Writing LC_TWOLEVEL_HINTS command\n");
1103 if (!unexec_write (curr_header_offset
, lc
, lc
->cmdsize
))
1104 unexec_error ("cannot write two level hint command to header");
1106 curr_header_offset
+= lc
->cmdsize
;
1110 /* Copy a LC_DYLD_INFO(_ONLY) load command from the input file to the output
1111 file, adjusting the file offset fields. */
1113 copy_dyld_info (struct load_command
*lc
, long delta
)
1115 struct dyld_info_command
*dip
= (struct dyld_info_command
*) lc
;
1117 if (dip
->rebase_off
> 0)
1118 dip
->rebase_off
+= delta
;
1119 if (dip
->bind_off
> 0)
1120 dip
->bind_off
+= delta
;
1121 if (dip
->weak_bind_off
> 0)
1122 dip
->weak_bind_off
+= delta
;
1123 if (dip
->lazy_bind_off
> 0)
1124 dip
->lazy_bind_off
+= delta
;
1125 if (dip
->export_off
> 0)
1126 dip
->export_off
+= delta
;
1128 printf ("Writing ");
1129 print_load_command_name (lc
->cmd
);
1130 printf (" command\n");
1132 if (!unexec_write (curr_header_offset
, lc
, lc
->cmdsize
))
1133 unexec_error ("cannot write dyld info command to header");
1135 curr_header_offset
+= lc
->cmdsize
;
1139 #ifdef LC_FUNCTION_STARTS
1140 /* Copy a LC_FUNCTION_STARTS load command from the input file to the
1141 output file, adjusting the data offset field. */
1143 copy_linkedit_data (struct load_command
*lc
, long delta
)
1145 struct linkedit_data_command
*ldp
= (struct linkedit_data_command
*) lc
;
1147 if (ldp
->dataoff
> 0)
1148 ldp
->dataoff
+= delta
;
1150 printf ("Writing ");
1151 print_load_command_name (lc
->cmd
);
1152 printf (" command\n");
1154 if (!unexec_write (curr_header_offset
, lc
, lc
->cmdsize
))
1155 unexec_error ("cannot write linkedit data command to header");
1157 curr_header_offset
+= lc
->cmdsize
;
1161 /* Copy other kinds of load commands from the input file to the output
1162 file, ones that do not require adjustments of file offsets. */
1164 copy_other (struct load_command
*lc
)
1166 printf ("Writing ");
1167 print_load_command_name (lc
->cmd
);
1168 printf (" command\n");
1170 if (!unexec_write (curr_header_offset
, lc
, lc
->cmdsize
))
1171 unexec_error ("cannot write symtab command to header");
1173 curr_header_offset
+= lc
->cmdsize
;
1176 /* Loop through all load commands and dump them. Then write the Mach
1182 long linkedit_delta
= 0;
1184 printf ("--- Load Commands written to Output File ---\n");
1186 for (i
= 0; i
< nlc
; i
++)
1187 switch (lca
[i
]->cmd
)
1191 struct segment_command
*scp
= (struct segment_command
*) lca
[i
];
1192 if (strncmp (scp
->segname
, SEG_DATA
, 16) == 0)
1194 /* save data segment file offset and segment_command for
1196 if (data_segment_old_fileoff
)
1197 unexec_error ("cannot handle multiple DATA segments"
1199 data_segment_old_fileoff
= scp
->fileoff
;
1200 data_segment_scp
= scp
;
1202 copy_data_segment (lca
[i
]);
1206 if (strncmp (scp
->segname
, SEG_LINKEDIT
, 16) == 0)
1209 unexec_error ("cannot handle multiple LINKEDIT segments"
1211 linkedit_delta
= curr_file_offset
- scp
->fileoff
;
1214 copy_segment (lca
[i
]);
1219 copy_symtab (lca
[i
], linkedit_delta
);
1222 copy_dysymtab (lca
[i
], linkedit_delta
);
1224 case LC_TWOLEVEL_HINTS
:
1225 copy_twolevelhints (lca
[i
], linkedit_delta
);
1229 case LC_DYLD_INFO_ONLY
:
1230 copy_dyld_info (lca
[i
], linkedit_delta
);
1233 #ifdef LC_FUNCTION_STARTS
1234 case LC_FUNCTION_STARTS
:
1235 copy_linkedit_data (lca
[i
], linkedit_delta
);
1239 copy_other (lca
[i
]);
1243 if (curr_header_offset
> text_seg_lowest_offset
)
1244 unexec_error ("not enough room for load commands for new __DATA segments");
1246 printf ("%ld unused bytes follow Mach-O header\n",
1247 text_seg_lowest_offset
- curr_header_offset
);
1249 mh
.sizeofcmds
= curr_header_offset
- sizeof (struct mach_header
);
1250 if (!unexec_write (0, &mh
, sizeof (struct mach_header
)))
1251 unexec_error ("cannot write final header contents");
1254 /* Take a snapshot of Emacs and make a Mach-O format executable file
1255 from it. The file names of the output and input files are outfile
1256 and infile, respectively. The three other parameters are
1259 unexec (char *outfile
, char *infile
, void *start_data
, void *start_bss
,
1260 void *entry_address
)
1263 unexec_error ("Unexec from a dumped executable is not supported.");
1265 pagesize
= getpagesize ();
1266 infd
= open (infile
, O_RDONLY
, 0);
1269 unexec_error ("cannot open input file `%s'", infile
);
1272 outfd
= open (outfile
, O_WRONLY
| O_TRUNC
| O_CREAT
, 0755);
1276 unexec_error ("cannot open output file `%s'", outfile
);
1279 build_region_list ();
1280 read_load_commands ();
1282 find_emacs_zone_regions ();
1283 unexec_regions_merge ();
1294 unexec_init_emacs_zone ()
1296 emacs_zone
= malloc_create_zone (0, 0);
1297 malloc_set_zone_name (emacs_zone
, "EmacsZone");
1300 #ifndef MACOSX_MALLOC_MULT16
1301 #define MACOSX_MALLOC_MULT16 1
1304 typedef struct unexec_malloc_header
{
1309 } unexec_malloc_header_t
;
1311 #if MACOSX_MALLOC_MULT16
1313 #define ptr_in_unexec_regions(p) ((((vm_address_t) (p)) & 8) != 0)
1318 ptr_in_unexec_regions (void *ptr
)
1322 for (i
= 0; i
< num_unexec_regions
; i
++)
1323 if ((vm_address_t
) ptr
- unexec_regions
[i
].range
.address
1324 < unexec_regions
[i
].range
.size
)
1333 unexec_malloc (size_t size
)
1340 #if MACOSX_MALLOC_MULT16
1341 assert (((vm_address_t
) p
% 16) == 0);
1347 unexec_malloc_header_t
*ptr
;
1349 ptr
= (unexec_malloc_header_t
*)
1350 malloc_zone_malloc (emacs_zone
, size
+ sizeof (unexec_malloc_header_t
));
1353 #if MACOSX_MALLOC_MULT16
1354 assert (((vm_address_t
) ptr
% 16) == 8);
1356 return (void *) ptr
;
1361 unexec_realloc (void *old_ptr
, size_t new_size
)
1367 if (ptr_in_unexec_regions (old_ptr
))
1369 size_t old_size
= ((unexec_malloc_header_t
*) old_ptr
)[-1].u
.size
;
1370 size_t size
= new_size
> old_size
? old_size
: new_size
;
1372 p
= (size_t *) malloc (new_size
);
1374 memcpy (p
, old_ptr
, size
);
1378 p
= realloc (old_ptr
, new_size
);
1380 #if MACOSX_MALLOC_MULT16
1381 assert (((vm_address_t
) p
% 16) == 0);
1387 unexec_malloc_header_t
*ptr
;
1389 ptr
= (unexec_malloc_header_t
*)
1390 malloc_zone_realloc (emacs_zone
, (unexec_malloc_header_t
*) old_ptr
- 1,
1391 new_size
+ sizeof (unexec_malloc_header_t
));
1392 ptr
->u
.size
= new_size
;
1394 #if MACOSX_MALLOC_MULT16
1395 assert (((vm_address_t
) ptr
% 16) == 8);
1397 return (void *) ptr
;
1402 unexec_free (void *ptr
)
1408 if (!ptr_in_unexec_regions (ptr
))
1412 malloc_zone_free (emacs_zone
, (unexec_malloc_header_t
*) ptr
- 1);
1415 /* arch-tag: 1a784f7b-a184-4c4f-9544-da8619593d72
1416 (do not change this comment) */