diff options
Diffstat (limited to 'src/unexmacosx.c')
| -rw-r--r-- | src/unexmacosx.c | 1401 |
1 files changed, 0 insertions, 1401 deletions
diff --git a/src/unexmacosx.c b/src/unexmacosx.c deleted file mode 100644 index 10524224711..00000000000 --- a/src/unexmacosx.c +++ /dev/null @@ -1,1401 +0,0 @@ -/* Dump Emacs in Mach-O format for use on macOS. - Copyright (C) 2001-2025 Free Software Foundation, Inc. - -This file is part of GNU Emacs. - -GNU Emacs is free software: you can redistribute it and/or modify -it under the terms of the GNU General Public License as published by -the Free Software Foundation, either version 3 of the License, or (at -your option) any later version. - -GNU Emacs is distributed in the hope that it will be useful, -but WITHOUT ANY WARRANTY; without even the implied warranty of -MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the -GNU General Public License for more details. - -You should have received a copy of the GNU General Public License -along with GNU Emacs. If not, see <https://www.gnu.org/licenses/>. */ - -/* Contributed by Andrew Choi (akochoi@mac.com). */ - -/* Documentation note. - - Consult the following documents/files for a description of the - Mach-O format: the file loader.h, man pages for Mach-O and ld, old - NEXTSTEP documents of the Mach-O format. The tool otool dumps the - mach header (-h option) and the load commands (-l option) in a - Mach-O file. The tool nm on macOS displays the symbol table in - a Mach-O file. For examples of unexec for the Mach-O format, see - the file unexnext.c in the GNU Emacs distribution, the file - unexdyld.c in the Darwin port of GNU Emacs 20.7, and unexdyld.c in - the Darwin port of XEmacs 21.1. Also the Darwin Libc source - contains the source code for malloc_freezedry and malloc_jumpstart. - Read that to see what they do. This file was written completely - from scratch, making use of information from the above sources. */ - -/* The macOS implementation of unexec makes use of Darwin's `zone' - memory allocator. All calls to malloc, realloc, and free in Emacs - are redirected to unexec_malloc, unexec_realloc, and unexec_free in - this file. When temacs is run, all memory requests are handled in - the zone EmacsZone. The Darwin memory allocator library calls - maintain the data structures to manage this zone. Dumping writes - its contents to data segments of the executable file. When emacs - is run, the loader recreates the contents of the zone in memory. - However since the initialization routine of the zone memory - allocator is run again, this `zone' can no longer be used as a - heap. That is why emacs uses the ordinary malloc system call to - allocate memory. Also, when a block of memory needs to be - reallocated and the new size is larger than the old one, a new - block must be obtained by malloc and the old contents copied to - it. */ - -/* Peculiarity of the Mach-O files generated by ld in macOS - (possible causes of future bugs if changed). - - The file offset of the start of the __TEXT segment is zero. Since - the Mach header and load commands are located at the beginning of a - Mach-O file, copying the contents of the __TEXT segment from the - input file overwrites them in the output file. Despite this, - unexec works fine as written below because the segment load command - for __TEXT appears, and is therefore processed, before all other - load commands except the segment load command for __PAGEZERO, which - remains unchanged. - - Although the file offset of the start of the __TEXT segment is - zero, none of the sections it contains actually start there. In - fact, the earliest one starts a few hundred bytes beyond the end of - the last load command. The linker option -headerpad controls the - minimum size of this padding. Its setting can be changed in - s/darwin.h. A value of 0x690, e.g., leaves room for 30 additional - load commands for the newly created __DATA segments (at 56 bytes - each). Unexec fails if there is not enough room for these new - segments. - - The __TEXT segment contains the sections __text, __cstring, - __picsymbol_stub, and __const and the __DATA segment contains the - sections __data, __la_symbol_ptr, __nl_symbol_ptr, __dyld, __bss, - and __common. The other segments do not contain any sections. - These sections are copied from the input file to the output file, - except for __data, __bss, and __common, which are dumped from - memory. The types of the sections __bss and __common are changed - from S_ZEROFILL to S_REGULAR. Note that the number of sections and - their relative order in the input and output files remain - unchanged. Otherwise all n_sect fields in the nlist records in the - symbol table (specified by the LC_SYMTAB load command) will have to - be changed accordingly. -*/ - -#include <config.h> - -#include <stdlib.h> - -#include "unexec.h" -#define UNEXMACOSX_C /* Tell lisp.h we want the system malloc, etc. */ -#include "lisp.h" -#include "sysstdio.h" - -#include <errno.h> -#include <fcntl.h> -#include <stdarg.h> -#include <stdint.h> -#include <sys/types.h> -#include <unistd.h> -#include <mach/mach.h> -#include <mach/vm_map.h> -#include <mach-o/loader.h> -#include <mach-o/reloc.h> -#ifdef HAVE_MALLOC_MALLOC_H -#include <malloc/malloc.h> -#else -#include <objc/malloc.h> -#endif - -#include <assert.h> - -/* LC_DATA_IN_CODE is not defined in mach-o/loader.h on Mac OS X 10.7. - But it is used if we build with "Command Line Tools for Xcode 4.5 - (Mac OS X Lion) - September 2012". */ -#ifndef LC_DATA_IN_CODE -#define LC_DATA_IN_CODE 0x29 /* table of non-instructions in __text */ -#endif - -#ifdef _LP64 -#define mach_header mach_header_64 -#define segment_command segment_command_64 -#undef VM_REGION_BASIC_INFO_COUNT -#define VM_REGION_BASIC_INFO_COUNT VM_REGION_BASIC_INFO_COUNT_64 -#undef VM_REGION_BASIC_INFO -#define VM_REGION_BASIC_INFO VM_REGION_BASIC_INFO_64 -#undef LC_SEGMENT -#define LC_SEGMENT LC_SEGMENT_64 -#define vm_region vm_region_64 -#define section section_64 -#undef MH_MAGIC -#define MH_MAGIC MH_MAGIC_64 -#endif - -#define VERBOSE 1 - -/* Size of buffer used to copy data from the input file to the output - file in function unexec_copy. */ -#define UNEXEC_COPY_BUFSZ 1024 - -/* Regions with memory addresses above this value are assumed to be - mapped to dynamically loaded libraries and will not be dumped. */ -#define VM_DATA_TOP (20 * 1024 * 1024) - -/* Type of an element on the list of regions to be dumped. */ -struct region_t { - vm_address_t address; - vm_size_t size; - vm_prot_t protection; - vm_prot_t max_protection; - - struct region_t *next; -}; - -/* Head and tail of the list of regions to be dumped. */ -static struct region_t *region_list_head = 0; -static struct region_t *region_list_tail = 0; - -/* Pointer to array of load commands. */ -static struct load_command **lca; - -/* Number of load commands. */ -static int nlc; - -/* The highest VM address of segments loaded by the input file. - Regions with addresses beyond this are assumed to be allocated - dynamically and thus require dumping. */ -static vm_address_t infile_lc_highest_addr = 0; - -/* The lowest file offset used by the all sections in the __TEXT - segments. This leaves room at the beginning of the file to store - the Mach-O header. Check this value against header size to ensure - the added load commands for the new __DATA segments did not - overwrite any of the sections in the __TEXT segment. */ -static unsigned long text_seg_lowest_offset = 0x10000000; - -/* Mach header. */ -static struct mach_header mh; - -/* Offset at which the next load command should be written. */ -static unsigned long curr_header_offset = sizeof (struct mach_header); - -/* Offset at which the next segment should be written. */ -static unsigned long curr_file_offset = 0; - -static unsigned long pagesize; -#define ROUNDUP_TO_PAGE_BOUNDARY(x) (((x) + pagesize - 1) & ~(pagesize - 1)) - -static int infd, outfd; - -static int in_dumped_exec = 0; - -static malloc_zone_t *emacs_zone; - -/* file offset of input file's data segment */ -static off_t data_segment_old_fileoff = 0; - -static struct segment_command *data_segment_scp; - -/* Read N bytes from infd into memory starting at address DEST. - Return true if successful, false otherwise. */ -static int -unexec_read (void *dest, size_t n) -{ - return n == read (infd, dest, n); -} - -/* Write COUNT bytes from memory starting at address SRC to outfd - starting at offset DEST. Return true if successful, false - otherwise. */ -static int -unexec_write (off_t dest, const void *src, size_t count) -{ - task_t task = mach_task_self(); - if (task == MACH_PORT_NULL || task == MACH_PORT_DEAD) - return false; - - if (lseek (outfd, dest, SEEK_SET) != dest) - return 0; - - /* We use the Mach virtual memory API to read our process memory - because using src directly would be undefined behavior and fails - under Address Sanitizer. */ - bool success = false; - vm_offset_t data; - mach_msg_type_number_t data_count; - if (vm_read (task, (uintptr_t) src, count, &data, &data_count) - == KERN_SUCCESS) - { - success = - write (outfd, (const void *) (uintptr_t) data, data_count) == count; - vm_deallocate (task, data, data_count); - } - return success; -} - -/* Write COUNT bytes of zeros to outfd starting at offset DEST. - Return true if successful, false otherwise. */ -static int -unexec_write_zero (off_t dest, size_t count) -{ - char buf[UNEXEC_COPY_BUFSZ]; - ssize_t bytes; - - memset (buf, 0, UNEXEC_COPY_BUFSZ); - if (lseek (outfd, dest, SEEK_SET) != dest) - return 0; - - while (count > 0) - { - bytes = min (count, UNEXEC_COPY_BUFSZ); - if (write (outfd, buf, bytes) != bytes) - return 0; - count -= bytes; - } - - return 1; -} - -/* Copy COUNT bytes from starting offset SRC in infd to starting - offset DEST in outfd. Return true if successful, false - otherwise. */ -static int -unexec_copy (off_t dest, off_t src, ssize_t count) -{ - ssize_t bytes_read; - ssize_t bytes_to_read; - - char buf[UNEXEC_COPY_BUFSZ]; - - if (lseek (infd, src, SEEK_SET) != src) - return 0; - - if (lseek (outfd, dest, SEEK_SET) != dest) - return 0; - - while (count > 0) - { - bytes_to_read = min (count, UNEXEC_COPY_BUFSZ); - bytes_read = read (infd, buf, bytes_to_read); - if (bytes_read <= 0) - return 0; - if (write (outfd, buf, bytes_read) != bytes_read) - return 0; - count -= bytes_read; - } - - return 1; -} - -/* Debugging and informational messages routines. */ - -static _Noreturn void -unexec_error (const char *format, ...) -{ - va_list ap; - - va_start (ap, format); - fputs ("unexec: ", stderr); - vfprintf (stderr, format, ap); - putc ('\n', stderr); - va_end (ap); - exit (1); -} - -static void -print_prot (vm_prot_t prot) -{ - if (prot == VM_PROT_NONE) - printf ("none"); - else - { - putchar (prot & VM_PROT_READ ? 'r' : ' '); - putchar (prot & VM_PROT_WRITE ? 'w' : ' '); - putchar (prot & VM_PROT_EXECUTE ? 'x' : ' '); - putchar (' '); - } -} - -static void -print_region (vm_address_t address, vm_size_t size, vm_prot_t prot, - vm_prot_t max_prot) -{ - printf ("%#10lx %#8lx ", (long) address, (long) size); - print_prot (prot); - putchar (' '); - print_prot (max_prot); - putchar ('\n'); -} - -static void -print_region_list (void) -{ - struct region_t *r; - - printf (" address size prot maxp\n"); - - for (r = region_list_head; r; r = r->next) - print_region (r->address, r->size, r->protection, r->max_protection); -} - -/* Build the list of regions that need to be dumped. Regions with - addresses above VM_DATA_TOP are omitted. Adjacent regions with - identical protection are merged. Note that non-writable regions - cannot be omitted because they some regions created at run time are - read-only. */ -static void -build_region_list (void) -{ - task_t target_task = mach_task_self (); - vm_address_t address = (vm_address_t) 0; - vm_size_t size; - struct vm_region_basic_info info; - mach_msg_type_number_t info_count = VM_REGION_BASIC_INFO_COUNT; - mach_port_t object_name; - struct region_t *r; - -#if VERBOSE - printf ("--- List of All Regions ---\n"); - printf (" address size prot maxp\n"); -#endif - - while (vm_region (target_task, &address, &size, VM_REGION_BASIC_INFO, - (vm_region_info_t) &info, &info_count, &object_name) - == KERN_SUCCESS && info_count == VM_REGION_BASIC_INFO_COUNT) - { - /* Done when we reach addresses of shared libraries, which are - loaded in high memory. */ - if (address >= VM_DATA_TOP) - break; - -#if VERBOSE - print_region (address, size, info.protection, info.max_protection); -#endif - - /* If a region immediately follows the previous one (the one - most recently added to the list) and has identical - protection, merge it with the latter. Otherwise create a - new list element for it. */ - if (region_list_tail - && info.protection == region_list_tail->protection - && info.max_protection == region_list_tail->max_protection - && region_list_tail->address + region_list_tail->size == address) - { - region_list_tail->size += size; - } - else - { - r = malloc (sizeof *r); - - if (!r) - unexec_error ("cannot allocate region structure"); - - r->address = address; - r->size = size; - r->protection = info.protection; - r->max_protection = info.max_protection; - - r->next = 0; - if (region_list_head == 0) - { - region_list_head = r; - region_list_tail = r; - } - else - { - region_list_tail->next = r; - region_list_tail = r; - } - - /* Deallocate (unused) object name returned by - vm_region. */ - if (object_name != MACH_PORT_NULL) - mach_port_deallocate (target_task, object_name); - } - - address += size; - } - - printf ("--- List of Regions to be Dumped ---\n"); - print_region_list (); -} - - -#define MAX_UNEXEC_REGIONS 400 - -static int num_unexec_regions; -typedef struct { - vm_range_t range; - vm_size_t filesize; -} unexec_region_info; -static unexec_region_info unexec_regions[MAX_UNEXEC_REGIONS]; - -static void -unexec_regions_recorder (task_t task, void *rr, unsigned type, - vm_range_t *ranges, unsigned num) -{ - vm_address_t p; - vm_size_t filesize; - - while (num && num_unexec_regions < MAX_UNEXEC_REGIONS) - { - /* Subtract the size of trailing null bytes from filesize. It - can be smaller than vmsize in segment commands. In such a - case, trailing bytes are initialized with zeros. */ - for (p = ranges->address + ranges->size; p > ranges->address; p--) - if (*(((char *) p)-1)) - break; - filesize = p - ranges->address; - - unexec_regions[num_unexec_regions].filesize = filesize; - unexec_regions[num_unexec_regions++].range = *ranges; - printf ("%#10lx (sz: %#8lx/%#8lx)\n", (long) (ranges->address), - (long) filesize, (long) (ranges->size)); - ranges++; num--; - } -} - -static kern_return_t -unexec_reader (task_t task, vm_address_t address, vm_size_t size, void **ptr) -{ - *ptr = (void *) address; - return KERN_SUCCESS; -} - -static void -find_emacs_zone_regions (void) -{ - num_unexec_regions = 0; - - emacs_zone->introspect->enumerator (mach_task_self (), 0, - MALLOC_PTR_REGION_RANGE_TYPE - | MALLOC_ADMIN_REGION_RANGE_TYPE, - (vm_address_t) emacs_zone, - unexec_reader, - unexec_regions_recorder); - - if (num_unexec_regions == MAX_UNEXEC_REGIONS) - unexec_error ("find_emacs_zone_regions: too many regions"); -} - -static int -unexec_regions_sort_compare (const void *a, const void *b) -{ - vm_address_t aa = ((unexec_region_info *) a)->range.address; - vm_address_t bb = ((unexec_region_info *) b)->range.address; - - if (aa < bb) - return -1; - else if (aa > bb) - return 1; - else - return 0; -} - -static void -unexec_regions_merge (void) -{ - qsort (unexec_regions, num_unexec_regions, sizeof (unexec_regions[0]), - &unexec_regions_sort_compare); - - /* Align each region start address to a page boundary. */ - for (unexec_region_info *cur = unexec_regions; - cur < unexec_regions + num_unexec_regions; cur++) - { - vm_size_t padsize = cur->range.address & (pagesize - 1); - if (padsize) - { - cur->range.address -= padsize; - cur->range.size += padsize; - cur->filesize += padsize; - - unexec_region_info *prev = cur == unexec_regions ? NULL : cur - 1; - if (prev - && prev->range.address + prev->range.size > cur->range.address) - { - prev->range.size = cur->range.address - prev->range.address; - if (prev->filesize > prev->range.size) - prev->filesize = prev->range.size; - } - } - } - - int n = 0; - unexec_region_info r = unexec_regions[0]; - for (int i = 1; i < num_unexec_regions; i++) - { - if (r.range.address + r.range.size == unexec_regions[i].range.address - && r.range.size - r.filesize < 2 * pagesize) - { - r.filesize = r.range.size + unexec_regions[i].filesize; - r.range.size += unexec_regions[i].range.size; - } - else - { - unexec_regions[n++] = r; - r = unexec_regions[i]; - } - } - unexec_regions[n++] = r; - num_unexec_regions = n; -} - - -/* More informational messages routines. */ - -static void -print_load_command_name (int lc) -{ - switch (lc) - { - case LC_SEGMENT: -#ifndef _LP64 - printf ("LC_SEGMENT "); -#else - printf ("LC_SEGMENT_64 "); -#endif - break; - case LC_LOAD_DYLINKER: - printf ("LC_LOAD_DYLINKER "); - break; - case LC_LOAD_DYLIB: - printf ("LC_LOAD_DYLIB "); - break; - case LC_SYMTAB: - printf ("LC_SYMTAB "); - break; - case LC_DYSYMTAB: - printf ("LC_DYSYMTAB "); - break; - case LC_UNIXTHREAD: - printf ("LC_UNIXTHREAD "); - break; - case LC_PREBOUND_DYLIB: - printf ("LC_PREBOUND_DYLIB"); - break; - case LC_TWOLEVEL_HINTS: - printf ("LC_TWOLEVEL_HINTS"); - break; -#ifdef LC_UUID - case LC_UUID: - printf ("LC_UUID "); - break; -#endif -#ifdef LC_DYLD_INFO - case LC_DYLD_INFO: - printf ("LC_DYLD_INFO "); - break; - case LC_DYLD_INFO_ONLY: - printf ("LC_DYLD_INFO_ONLY"); - break; -#endif -#ifdef LC_VERSION_MIN_MACOSX - case LC_VERSION_MIN_MACOSX: - printf ("LC_VERSION_MIN_MACOSX"); - break; -#endif -#ifdef LC_FUNCTION_STARTS - case LC_FUNCTION_STARTS: - printf ("LC_FUNCTION_STARTS"); - break; -#endif -#ifdef LC_MAIN - case LC_MAIN: - printf ("LC_MAIN "); - break; -#endif -#ifdef LC_DATA_IN_CODE - case LC_DATA_IN_CODE: - printf ("LC_DATA_IN_CODE "); - break; -#endif -#ifdef LC_SOURCE_VERSION - case LC_SOURCE_VERSION: - printf ("LC_SOURCE_VERSION"); - break; -#endif -#ifdef LC_DYLIB_CODE_SIGN_DRS - case LC_DYLIB_CODE_SIGN_DRS: - printf ("LC_DYLIB_CODE_SIGN_DRS"); - break; -#endif - default: - printf ("unknown "); - } -} - -static void -print_load_command (struct load_command *lc) -{ - print_load_command_name (lc->cmd); - printf ("%8d", lc->cmdsize); - - if (lc->cmd == LC_SEGMENT) - { - struct segment_command *scp; - struct section *sectp; - int j; - - scp = (struct segment_command *) lc; - printf (" %-16.16s %#10lx %#8lx\n", - scp->segname, (long) (scp->vmaddr), (long) (scp->vmsize)); - - sectp = (struct section *) (scp + 1); - for (j = 0; j < scp->nsects; j++) - { - printf (" %-16.16s %#10lx %#8lx\n", - sectp->sectname, (long) (sectp->addr), (long) (sectp->size)); - sectp++; - } - } - else - printf ("\n"); -} - -/* Read header and load commands from input file. Store the latter in - the global array lca. Store the total number of load commands in - global variable nlc. */ -static void -read_load_commands (void) -{ - int i; - - if (!unexec_read (&mh, sizeof (struct mach_header))) - unexec_error ("cannot read mach-o header"); - - if (mh.magic != MH_MAGIC) - unexec_error ("input file not in Mach-O format"); - - if (mh.filetype != MH_EXECUTE) - unexec_error ("input Mach-O file is not an executable object file"); - -#if VERBOSE - printf ("--- Header Information ---\n"); - printf ("Magic = 0x%08x\n", mh.magic); - printf ("CPUType = %d\n", mh.cputype); - printf ("CPUSubType = %d\n", mh.cpusubtype); - printf ("FileType = 0x%x\n", mh.filetype); - printf ("NCmds = %d\n", mh.ncmds); - printf ("SizeOfCmds = %d\n", mh.sizeofcmds); - printf ("Flags = 0x%08x\n", mh.flags); -#endif - - nlc = mh.ncmds; - lca = malloc (nlc * sizeof *lca); - - for (i = 0; i < nlc; i++) - { - struct load_command lc; - /* Load commands are variable-size: so read the command type and - size first and then read the rest. */ - if (!unexec_read (&lc, sizeof (struct load_command))) - unexec_error ("cannot read load command"); - lca[i] = malloc (lc.cmdsize); - memcpy (lca[i], &lc, sizeof (struct load_command)); - if (!unexec_read (lca[i] + 1, lc.cmdsize - sizeof (struct load_command))) - unexec_error ("cannot read content of load command"); - if (lc.cmd == LC_SEGMENT) - { - struct segment_command *scp = (struct segment_command *) lca[i]; - - if (scp->vmaddr + scp->vmsize > infile_lc_highest_addr) - infile_lc_highest_addr = scp->vmaddr + scp->vmsize; - - if (strncmp (scp->segname, SEG_TEXT, 16) == 0) - { - struct section *sectp = (struct section *) (scp + 1); - int j; - - for (j = 0; j < scp->nsects; j++) - if (sectp->offset < text_seg_lowest_offset) - text_seg_lowest_offset = sectp->offset; - } - } - } - - printf ("Highest address of load commands in input file: %#8lx\n", - (unsigned long)infile_lc_highest_addr); - - printf ("Lowest offset of all sections in __TEXT segment: %#8lx\n", - text_seg_lowest_offset); - - printf ("--- List of Load Commands in Input File ---\n"); - printf ("# cmd cmdsize name address size\n"); - - for (i = 0; i < nlc; i++) - { - printf ("%1d ", i); - print_load_command (lca[i]); - } -} - -/* Copy a LC_SEGMENT load command other than the __DATA segment from - the input file to the output file, adjusting the file offset of the - segment and the file offsets of sections contained in it. */ -static void -copy_segment (struct load_command *lc) -{ - struct segment_command *scp = (struct segment_command *) lc; - unsigned long old_fileoff = scp->fileoff; - struct section *sectp; - int j; - - scp->fileoff = curr_file_offset; - - sectp = (struct section *) (scp + 1); - for (j = 0; j < scp->nsects; j++) - { - sectp->offset += curr_file_offset - old_fileoff; - sectp++; - } - - printf ("Writing segment %-16.16s @ %#8lx (%#8lx/%#8lx @ %#10lx)\n", - scp->segname, (long) (scp->fileoff), (long) (scp->filesize), - (long) (scp->vmsize), (long) (scp->vmaddr)); - - if (!unexec_copy (scp->fileoff, old_fileoff, scp->filesize)) - unexec_error ("cannot copy segment from input to output file"); - curr_file_offset += ROUNDUP_TO_PAGE_BOUNDARY (scp->filesize); - - if (!unexec_write (curr_header_offset, lc, lc->cmdsize)) - unexec_error ("cannot write load command to header"); - - curr_header_offset += lc->cmdsize; -} - -/* Copy a LC_SEGMENT load command for the __DATA segment in the input - file to the output file. We assume that only one such segment load - command exists in the input file and it contains the sections - __data, __bss, __common, __la_symbol_ptr, __nl_symbol_ptr, and - __dyld. The first three of these should be dumped from memory and - the rest should be copied from the input file. Note that the - sections __bss and __common contain no data in the input file - because their flag fields have the value S_ZEROFILL. Dumping these - from memory makes it necessary to adjust file offset fields in - subsequently dumped load commands. Then, create new __DATA segment - load commands for regions on the region list other than the one - corresponding to the __DATA segment in the input file. */ -static void -copy_data_segment (struct load_command *lc) -{ - struct segment_command *scp = (struct segment_command *) lc; - struct section *sectp; - int j; - unsigned long header_offset, old_file_offset; - - /* The new filesize of the segment is set to its vmsize because data - blocks for segments must start at region boundaries. Note that - this may leave unused locations at the end of the segment data - block because the total of the sizes of all sections in the - segment is generally smaller than vmsize. */ - scp->filesize = scp->vmsize; - - printf ("Writing segment %-16.16s @ %#8lx (%#8lx/%#8lx @ %#10lx)\n", - scp->segname, curr_file_offset, (long)(scp->filesize), - (long)(scp->vmsize), (long) (scp->vmaddr)); - - /* Offsets in the output file for writing the next section structure - and segment data block, respectively. */ - header_offset = curr_header_offset + sizeof (struct segment_command); - - sectp = (struct section *) (scp + 1); - for (j = 0; j < scp->nsects; j++) - { - old_file_offset = sectp->offset; - sectp->offset = sectp->addr - scp->vmaddr + curr_file_offset; - /* The __data section is dumped from memory. The __bss and - __common sections are also dumped from memory but their flag - fields require changing (from S_ZEROFILL to S_REGULAR). The - other three kinds of sections are just copied from the input - file. */ - if (strncmp (sectp->sectname, SECT_DATA, 16) == 0) - { - unsigned long my_size; - - /* The __data section is basically dumped from memory. But - initialized data in statically linked libraries are - copied from the input file. In particular, - add_image_hook.names and add_image_hook.pointers stored - by libarclite_macosx.a, are restored so that they will be - reinitialized when the dumped binary is executed. */ - my_size = (unsigned long)my_edata - sectp->addr; - if (!(sectp->addr <= (unsigned long)my_edata - && my_size <= sectp->size)) - unexec_error ("my_edata is not in section %s", SECT_DATA); - if (!unexec_write (sectp->offset, (void *) sectp->addr, my_size)) - unexec_error ("cannot write section %s", SECT_DATA); - if (!unexec_copy (sectp->offset + my_size, old_file_offset + my_size, - sectp->size - my_size)) - unexec_error ("cannot copy section %s", SECT_DATA); - if (!unexec_write (header_offset, sectp, sizeof (struct section))) - unexec_error ("cannot write section %s's header", SECT_DATA); - } - else if (strncmp (sectp->sectname, SECT_COMMON, 16) == 0) - { - sectp->flags = S_REGULAR; - if (!unexec_write (sectp->offset, (void *) sectp->addr, sectp->size)) - unexec_error ("cannot write section %.16s", sectp->sectname); - if (!unexec_write (header_offset, sectp, sizeof (struct section))) - unexec_error ("cannot write section %.16s's header", sectp->sectname); - } - else if (strncmp (sectp->sectname, SECT_BSS, 16) == 0) - { - unsigned long my_size; - - sectp->flags = S_REGULAR; - - /* Clear uninitialized local variables in statically linked - libraries. In particular, function pointers stored by - libSystemStub.a, which is introduced in Mac OS X 10.4 for - binary compatibility with respect to long double, are - cleared so that they will be reinitialized when the - dumped binary is executed on other versions of OS. */ - my_size = (unsigned long)my_endbss_static - sectp->addr; - if (!(sectp->addr <= (unsigned long)my_endbss_static - && my_size <= sectp->size)) - unexec_error ("my_endbss_static is not in section %.16s", - sectp->sectname); - if (!unexec_write (sectp->offset, (void *) sectp->addr, my_size)) - unexec_error ("cannot write section %.16s", sectp->sectname); - if (!unexec_write_zero (sectp->offset + my_size, - sectp->size - my_size)) - unexec_error ("cannot write section %.16s", sectp->sectname); - if (!unexec_write (header_offset, sectp, sizeof (struct section))) - unexec_error ("cannot write section %.16s's header", sectp->sectname); - } - else if (strncmp (sectp->sectname, "__bss", 5) == 0 - || strncmp (sectp->sectname, "__pu_bss", 8) == 0) - { - sectp->flags = S_REGULAR; - - /* These sections are produced by GCC 4.6+. - - FIXME: We possibly ought to clear uninitialized local - variables in statically linked libraries like for - SECT_BSS (__bss) above, but setting up the markers we - need in lastfile.c would be rather messy. See - darwin_output_aligned_bss () in gcc/config/darwin.c for - the root of the problem, keeping in mind that the - sections are numbered by their alignment in GCC 4.6, but - by log2(alignment) in GCC 4.7. */ - - if (!unexec_write (sectp->offset, (void *) sectp->addr, sectp->size)) - unexec_error ("cannot copy section %.16s", sectp->sectname); - if (!unexec_write (header_offset, sectp, sizeof (struct section))) - unexec_error ("cannot write section %.16s's header", sectp->sectname); - } - else if (strncmp (sectp->sectname, "__la_symbol_ptr", 16) == 0 - || strncmp (sectp->sectname, "__nl_symbol_ptr", 16) == 0 - || strncmp (sectp->sectname, "__got", 16) == 0 - || strncmp (sectp->sectname, "__la_sym_ptr2", 16) == 0 - || strncmp (sectp->sectname, "__dyld", 16) == 0 - || strncmp (sectp->sectname, "__const", 16) == 0 - || strncmp (sectp->sectname, "__cfstring", 16) == 0 - || strncmp (sectp->sectname, "__gcc_except_tab", 16) == 0 - || strncmp (sectp->sectname, "__program_vars", 16) == 0 - || strncmp (sectp->sectname, "__mod_init_func", 16) == 0 - || strncmp (sectp->sectname, "__mod_term_func", 16) == 0 - || strncmp (sectp->sectname, "__static_data", 16) == 0 - || strncmp (sectp->sectname, "__objc_", 7) == 0) - { - if (!unexec_copy (sectp->offset, old_file_offset, sectp->size)) - unexec_error ("cannot copy section %.16s", sectp->sectname); - if (!unexec_write (header_offset, sectp, sizeof (struct section))) - unexec_error ("cannot write section %.16s's header", sectp->sectname); - } - else - unexec_error ("unrecognized section %.16s in __DATA segment", - sectp->sectname); - - printf (" section %-16.16s at %#8lx - %#8lx (sz: %#8lx)\n", - sectp->sectname, (long) (sectp->offset), - (long) (sectp->offset + sectp->size), (long) (sectp->size)); - - header_offset += sizeof (struct section); - sectp++; - } - - curr_file_offset += ROUNDUP_TO_PAGE_BOUNDARY (scp->filesize); - - if (!unexec_write (curr_header_offset, scp, sizeof (struct segment_command))) - unexec_error ("cannot write header of __DATA segment"); - curr_header_offset += lc->cmdsize; - - /* Create new __DATA segment load commands for regions on the region - list that do not corresponding to any segment load commands in - the input file. - */ - for (j = 0; j < num_unexec_regions; j++) - { - struct segment_command sc; - - sc.cmd = LC_SEGMENT; - sc.cmdsize = sizeof (struct segment_command); - strncpy (sc.segname, SEG_DATA, 16); - sc.vmaddr = unexec_regions[j].range.address; - sc.vmsize = unexec_regions[j].range.size; - sc.fileoff = curr_file_offset; - sc.filesize = unexec_regions[j].filesize; - sc.maxprot = VM_PROT_READ | VM_PROT_WRITE; - sc.initprot = VM_PROT_READ | VM_PROT_WRITE; - sc.nsects = 0; - sc.flags = 0; - - printf ("Writing segment %-16.16s @ %#8lx (%#8lx/%#8lx @ %#10lx)\n", - sc.segname, (long) (sc.fileoff), (long) (sc.filesize), - (long) (sc.vmsize), (long) (sc.vmaddr)); - - if (!unexec_write (sc.fileoff, (void *) sc.vmaddr, sc.filesize)) - unexec_error ("cannot write new __DATA segment"); - curr_file_offset += ROUNDUP_TO_PAGE_BOUNDARY (sc.filesize); - - if (!unexec_write (curr_header_offset, &sc, sc.cmdsize)) - unexec_error ("cannot write new __DATA segment's header"); - curr_header_offset += sc.cmdsize; - mh.ncmds++; - } -} - -/* Copy a LC_SYMTAB load command from the input file to the output - file, adjusting the file offset fields. */ -static void -copy_symtab (struct load_command *lc, long delta) -{ - struct symtab_command *stp = (struct symtab_command *) lc; - - stp->symoff += delta; - stp->stroff += delta; - - printf ("Writing LC_SYMTAB command\n"); - - if (!unexec_write (curr_header_offset, lc, lc->cmdsize)) - unexec_error ("cannot write symtab command to header"); - - curr_header_offset += lc->cmdsize; -} - -/* Fix up relocation entries. */ -static void -unrelocate (const char *name, off_t reloff, int nrel, vm_address_t base) -{ - int i, unreloc_count; - struct relocation_info reloc_info; - struct scattered_relocation_info *sc_reloc_info - = (struct scattered_relocation_info *) &reloc_info; - vm_address_t location; - - for (unreloc_count = 0, i = 0; i < nrel; i++) - { - if (lseek (infd, reloff, L_SET) != reloff) - unexec_error ("unrelocate: %s:%d cannot seek to reloc_info", name, i); - if (!unexec_read (&reloc_info, sizeof (reloc_info))) - unexec_error ("unrelocate: %s:%d cannot read reloc_info", name, i); - reloff += sizeof (reloc_info); - - if (sc_reloc_info->r_scattered == 0) - switch (reloc_info.r_type) - { - case GENERIC_RELOC_VANILLA: - location = base + reloc_info.r_address; - if (location >= data_segment_scp->vmaddr - && location < (data_segment_scp->vmaddr - + data_segment_scp->vmsize)) - { - off_t src_off = data_segment_old_fileoff - + (location - data_segment_scp->vmaddr); - off_t dst_off = data_segment_scp->fileoff - + (location - data_segment_scp->vmaddr); - - if (!unexec_copy (dst_off, src_off, 1 << reloc_info.r_length)) - unexec_error ("unrelocate: %s:%d cannot copy original value", - name, i); - unreloc_count++; - } - break; - default: - unexec_error ("unrelocate: %s:%d cannot handle type = %d", - name, i, reloc_info.r_type); - } - else - unexec_error ("unrelocate: %s:%d cannot handle scattered type = %d", - name, i, sc_reloc_info->r_type); - } - - if (nrel > 0) - printf ("Fixed up %d/%d %s relocation entries in data segment.\n", - unreloc_count, nrel, name); -} - -/* Copy a LC_DYSYMTAB load command from the input file to the output - file, adjusting the file offset fields. */ -static void -copy_dysymtab (struct load_command *lc, long delta) -{ - struct dysymtab_command *dstp = (struct dysymtab_command *) lc; - vm_address_t base; - -#ifdef _LP64 - /* First writable segment address. */ - base = data_segment_scp->vmaddr; -#else - /* First segment address in the file (unless MH_SPLIT_SEGS set). */ - base = 0; -#endif - - unrelocate ("local", dstp->locreloff, dstp->nlocrel, base); - unrelocate ("external", dstp->extreloff, dstp->nextrel, base); - - if (dstp->nextrel > 0) { - dstp->extreloff += delta; - } - - if (dstp->nlocrel > 0) { - dstp->locreloff += delta; - } - - if (dstp->nindirectsyms > 0) - dstp->indirectsymoff += delta; - - printf ("Writing LC_DYSYMTAB command\n"); - - if (!unexec_write (curr_header_offset, lc, lc->cmdsize)) - unexec_error ("cannot write symtab command to header"); - - curr_header_offset += lc->cmdsize; -} - -/* Copy a LC_TWOLEVEL_HINTS load command from the input file to the output - file, adjusting the file offset fields. */ -static void -copy_twolevelhints (struct load_command *lc, long delta) -{ - struct twolevel_hints_command *tlhp = (struct twolevel_hints_command *) lc; - - if (tlhp->nhints > 0) { - tlhp->offset += delta; - } - - printf ("Writing LC_TWOLEVEL_HINTS command\n"); - - if (!unexec_write (curr_header_offset, lc, lc->cmdsize)) - unexec_error ("cannot write two level hint command to header"); - - curr_header_offset += lc->cmdsize; -} - -#ifdef LC_DYLD_INFO -/* Copy a LC_DYLD_INFO(_ONLY) load command from the input file to the output - file, adjusting the file offset fields. */ -static void -copy_dyld_info (struct load_command *lc, long delta) -{ - struct dyld_info_command *dip = (struct dyld_info_command *) lc; - - if (dip->rebase_off > 0) - dip->rebase_off += delta; - if (dip->bind_off > 0) - dip->bind_off += delta; - if (dip->weak_bind_off > 0) - dip->weak_bind_off += delta; - if (dip->lazy_bind_off > 0) - dip->lazy_bind_off += delta; - if (dip->export_off > 0) - dip->export_off += delta; - - printf ("Writing "); - print_load_command_name (lc->cmd); - printf (" command\n"); - - if (!unexec_write (curr_header_offset, lc, lc->cmdsize)) - unexec_error ("cannot write dyld info command to header"); - - curr_header_offset += lc->cmdsize; -} -#endif - -#ifdef LC_FUNCTION_STARTS -/* Copy a LC_FUNCTION_STARTS/LC_DATA_IN_CODE/LC_DYLIB_CODE_SIGN_DRS - load command from the input file to the output file, adjusting the - data offset field. */ -static void -copy_linkedit_data (struct load_command *lc, long delta) -{ - struct linkedit_data_command *ldp = (struct linkedit_data_command *) lc; - - if (ldp->dataoff > 0) - ldp->dataoff += delta; - - printf ("Writing "); - print_load_command_name (lc->cmd); - printf (" command\n"); - - if (!unexec_write (curr_header_offset, lc, lc->cmdsize)) - unexec_error ("cannot write linkedit data command to header"); - - curr_header_offset += lc->cmdsize; -} -#endif - -/* Copy other kinds of load commands from the input file to the output - file, ones that do not require adjustments of file offsets. */ -static void -copy_other (struct load_command *lc) -{ - printf ("Writing "); - print_load_command_name (lc->cmd); - printf (" command\n"); - - if (!unexec_write (curr_header_offset, lc, lc->cmdsize)) - unexec_error ("cannot write symtab command to header"); - - curr_header_offset += lc->cmdsize; -} - -/* Loop through all load commands and dump them. Then write the Mach - header. */ -static void -dump_it (void) -{ - int i; - long linkedit_delta = 0; - - printf ("--- Load Commands written to Output File ---\n"); - - for (i = 0; i < nlc; i++) - switch (lca[i]->cmd) - { - case LC_SEGMENT: - { - struct segment_command *scp = (struct segment_command *) lca[i]; - if (strncmp (scp->segname, SEG_DATA, 16) == 0) - { - /* save data segment file offset and segment_command for - unrelocate */ - if (data_segment_old_fileoff) - unexec_error ("cannot handle multiple DATA segments" - " in input file"); - data_segment_old_fileoff = scp->fileoff; - data_segment_scp = scp; - - copy_data_segment (lca[i]); - } - else - { - if (strncmp (scp->segname, SEG_LINKEDIT, 16) == 0) - { - if (linkedit_delta) - unexec_error ("cannot handle multiple LINKEDIT segments" - " in input file"); - linkedit_delta = curr_file_offset - scp->fileoff; - } - - copy_segment (lca[i]); - } - } - break; - case LC_SYMTAB: - copy_symtab (lca[i], linkedit_delta); - break; - case LC_DYSYMTAB: - copy_dysymtab (lca[i], linkedit_delta); - break; - case LC_TWOLEVEL_HINTS: - copy_twolevelhints (lca[i], linkedit_delta); - break; -#ifdef LC_DYLD_INFO - case LC_DYLD_INFO: - case LC_DYLD_INFO_ONLY: - copy_dyld_info (lca[i], linkedit_delta); - break; -#endif -#ifdef LC_FUNCTION_STARTS - case LC_FUNCTION_STARTS: -#ifdef LC_DATA_IN_CODE - case LC_DATA_IN_CODE: -#endif -#ifdef LC_DYLIB_CODE_SIGN_DRS - case LC_DYLIB_CODE_SIGN_DRS: -#endif - copy_linkedit_data (lca[i], linkedit_delta); - break; -#endif - default: - copy_other (lca[i]); - break; - } - - if (curr_header_offset > text_seg_lowest_offset) - unexec_error ("not enough room for load commands for new __DATA segments" - " (increase headerpad_extra in configure.in to at least %lX)", - num_unexec_regions * sizeof (struct segment_command)); - - printf ("%ld unused bytes follow Mach-O header\n", - text_seg_lowest_offset - curr_header_offset); - - mh.sizeofcmds = curr_header_offset - sizeof (struct mach_header); - if (!unexec_write (0, &mh, sizeof (struct mach_header))) - unexec_error ("cannot write final header contents"); -} - -/* Take a snapshot of Emacs and make a Mach-O format executable file - from it. The file names of the output and input files are outfile - and infile, respectively. The three other parameters are - ignored. */ -void -unexec (const char *outfile, const char *infile) -{ - if (in_dumped_exec) - unexec_error ("Unexec from a dumped executable is not supported."); - - pagesize = getpagesize (); - infd = emacs_open (infile, O_RDONLY, 0); - if (infd < 0) - { - unexec_error ("%s: %s", infile, strerror (errno)); - } - - outfd = emacs_open (outfile, O_WRONLY | O_TRUNC | O_CREAT, 0777); - if (outfd < 0) - { - emacs_close (infd); - unexec_error ("%s: %s", outfile, strerror (errno)); - } - - build_region_list (); - read_load_commands (); - - find_emacs_zone_regions (); - unexec_regions_merge (); - - in_dumped_exec = 1; - - dump_it (); - - emacs_close (outfd); -} - - -void -unexec_init_emacs_zone (void) -{ - emacs_zone = malloc_create_zone (0, 0); - malloc_set_zone_name (emacs_zone, "EmacsZone"); -} - -#ifndef MACOSX_MALLOC_MULT16 -#define MACOSX_MALLOC_MULT16 1 -#endif - -typedef struct unexec_malloc_header { - union { - char c[8]; - size_t size; - } u; -} unexec_malloc_header_t; - -#if MACOSX_MALLOC_MULT16 - -#define ptr_in_unexec_regions(p) ((((vm_address_t) (p)) & 8) != 0) - -#else - -int -ptr_in_unexec_regions (void *ptr) -{ - int i; - - for (i = 0; i < num_unexec_regions; i++) - if ((vm_address_t) ptr - unexec_regions[i].range.address - < unexec_regions[i].range.size) - return 1; - - return 0; -} - -#endif - -void * -unexec_malloc (size_t size) -{ - if (in_dumped_exec) - { - void *p; - - p = malloc (size); -#if MACOSX_MALLOC_MULT16 - assert (((vm_address_t) p % 16) == 0); -#endif - return p; - } - else - { - unexec_malloc_header_t *ptr; - - ptr = (unexec_malloc_header_t *) - malloc_zone_malloc (emacs_zone, size + sizeof (unexec_malloc_header_t)); - ptr->u.size = size; - ptr++; -#if MACOSX_MALLOC_MULT16 - assert (((vm_address_t) ptr % 16) == 8); -#endif - return (void *) ptr; - } -} - -void * -unexec_realloc (void *old_ptr, size_t new_size) -{ - if (in_dumped_exec) - { - void *p; - - if (ptr_in_unexec_regions (old_ptr)) - { - size_t old_size = ((unexec_malloc_header_t *) old_ptr)[-1].u.size; - size_t size = min (new_size, old_size); - - p = malloc (new_size); - if (size) - memcpy (p, old_ptr, size); - } - else - { - p = realloc (old_ptr, new_size); - } -#if MACOSX_MALLOC_MULT16 - assert (((vm_address_t) p % 16) == 0); -#endif - return p; - } - else - { - unexec_malloc_header_t *ptr; - - ptr = (unexec_malloc_header_t *) - malloc_zone_realloc (emacs_zone, (unexec_malloc_header_t *) old_ptr - 1, - new_size + sizeof (unexec_malloc_header_t)); - ptr->u.size = new_size; - ptr++; -#if MACOSX_MALLOC_MULT16 - assert (((vm_address_t) ptr % 16) == 8); -#endif - return (void *) ptr; - } -} - -void -unexec_free (void *ptr) -{ - if (ptr == NULL) - return; - if (in_dumped_exec) - { - if (!ptr_in_unexec_regions (ptr)) - free (ptr); - } - else - malloc_zone_free (emacs_zone, (unexec_malloc_header_t *) ptr - 1); -} |