cctools-port/cctools/misc/segedit.c

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/*
* Copyright (c) 1999 Apple Computer, Inc. All rights reserved.
*
* @APPLE_LICENSE_HEADER_START@
*
* This file contains Original Code and/or Modifications of Original Code
* as defined in and that are subject to the Apple Public Source License
* Version 2.0 (the 'License'). You may not use this file except in
* compliance with the License. Please obtain a copy of the License at
* http://www.opensource.apple.com/apsl/ and read it before using this
* file.
*
* The Original Code and all software distributed under the License are
* distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
* EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
* INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
* Please see the License for the specific language governing rights and
* limitations under the License.
*
* @APPLE_LICENSE_HEADER_END@
*/
/*
* The segedit(1) program. This program extracts and replaces sections from
* an object file. Only sections in segments that have been marked that they
* have no relocation can be replaced (SG_NORELOC). This program takes the
* following options:
* -extract <segname> <sectname> <filename>
* -replace <segname> <sectname> <filename>
* -output <filename>
*/
#include <stdlib.h>
#include <stdarg.h>
#include <string.h>
#include <errno.h>
#include <stdio.h>
#include <sys/file.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/mman.h>
#include <libc.h>
#include <mach-o/loader.h>
#include <mach-o/fat.h>
#include <mach/mach.h>
#include "stuff/openstep_mach.h"
#include <mach/mach_error.h>
#include "stuff/allocate.h"
#include "stuff/errors.h"
#include "stuff/rnd.h"
#include "stuff/bytesex.h"
/* These variables are set from the command line arguments */
__private_extern__
char *progname = NULL; /* name of the program for error messages (argv[0]) */
static char *input, /* object file to extract/replace sections from */
*output; /* new object file with replaced sections, if any
-replace options */
/* structure for holding -extract's arguments */
struct extract {
char *segname; /* segment name */
char *sectname; /* section name */
char *filename; /* file to put the section contents in */
int32_t found; /* set when the section is found */
struct extract *next; /* next extract structure, NULL if last */
} *extracts; /* first extract structure, NULL if none */
/* structure for holding -replace's arguments */
struct replace {
char *segname; /* segment name */
char *sectname; /* section name */
char *filename; /* file to get the section contents from */
int32_t found; /* set when the section is found */
uint32_t size; /* size of new section contents */
struct replace *next; /* next replace structure, NULL if last */
} *replaces; /* first replace structure, NULL if none */
/*
* Structures used in replace_sections in replaceing sections in the segments
* of the input file. There is one such structure for each segment and section.
*/
struct rep_seg {
int32_t modified; /* this segment has a replaced section */
uint32_t fileoff; /* original file offset */
uint32_t filesize; /* original file size */
uint64_t vmsize; /* original vm size */
uint32_t padsize; /* new pad size */
struct segment_command *sgp;/* pointer to the segment_command */
struct segment_command_64 *sgp64;/* pointer to the segment_command_64 */
} *segs;
struct rep_sect {
struct replace *rp; /* pointer to the replace structure */
uint32_t offset; /* original file offset */
struct section *sp; /* pointer to the section structure */
struct section_64 *sp64; /* pointer to the section_64 structure */
} *sects;
/* These variables are set in the routine map_input() */
static void *input_addr; /* address of where the input file is mapped */
static uint32_t input_size; /* size of the input file */
static uint32_t input_mode; /* mode of the input file */
static struct mach_header *mhp; /* pointer to the input file's mach header */
static struct mach_header_64
*mhp64; /* pointer to the input file's mach header for
64-bit files */
static uint32_t mh_ncmds; /* number of load commands */
static struct load_command
*load_commands; /* pointer to the input file's load commands */
static uint32_t pagesize = 8192;/* target pagesize */
static enum bool swapped; /* TRUE if the input is to be swapped */
static enum byte_sex host_byte_sex = UNKNOWN_BYTE_SEX;
static enum byte_sex target_byte_sex = UNKNOWN_BYTE_SEX;
/* Internal routines */
static void map_input(
void);
static void extract_sections(
void);
static void extract_section(
char *segname,
char *sectname,
uint32_t flags,
uint32_t offset,
uint32_t size);
static void replace_sections(
void);
static void search_for_replace_section(
char *segname,
char *sectname,
uint32_t seg_flags,
uint32_t sect_flags,
uint32_t offset,
uint32_t size);
static int cmp_qsort(
const struct rep_seg *seg1,
const struct rep_seg *seg2);
static void usage(
void);
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/*
* MDT: The following routines have been copied from lipo.c to guess the page
* alignment based on the mach header. They really should move to libstuff.
*/
/* The maximum section alignment allowed to be specified, as a power of two */
#define MAXSECTALIGN 15 /* 2**15 or 0x8000 */
static uint32_t get_align(
struct mach_header *mhp,
struct load_command *load_commands,
uint64_t size,
char *name,
enum bool swapped);
static uint32_t get_align_64(
struct mach_header_64 *mhp64,
struct load_command *load_commands,
uint64_t size,
char *name,
enum bool swapped);
static uint32_t guess_align(
uint64_t vmaddr);
/*
* MDT: End of alignment routines
*/
int
main(
int argc,
char *argv[],
char *envp[])
{
int i;
struct extract *ep;
struct replace *rp;
progname = argv[0];
host_byte_sex = get_host_byte_sex();
for (i = 1; i < argc; i++) {
if(argv[i][0] == '-'){
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if (strncmp("-extract", argv[i], 9) == 0 ||
strncmp("-e", argv[i], 3) == 0) {
if(i + 4 > argc){
error("missing arguments to %s option", argv[i]);
usage();
}
ep = allocate(sizeof(struct extract));
ep->segname = argv[i + 1];
ep->sectname = argv[i + 2];
ep->filename = argv[i + 3];
ep->found = 0;
ep->next = extracts;
extracts = ep;
i += 3;
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}
else if (strncmp("-replace", argv[i], 9) == 0 ||
strncmp("-r", argv[i], 3) == 0) {
if(i + 4 > argc){
error("missing arguments to %s option", argv[i]);
usage();
}
rp = allocate(sizeof(struct replace));
rp->segname = argv[i + 1];
rp->sectname = argv[i + 2];
rp->filename = argv[i + 3];
rp->next = replaces;
replaces = rp;
i += 3;
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}
else if (strncmp("-output", argv[i], 8) == 0 ||
strncmp("-o", argv[i], 3) == 0) {
if(output != NULL)
fatal("more than one %s option", argv[i]);
output = argv[i + 1];
i += 1;
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}
else {
error("unrecognized option: %s", argv[i]);
usage();
}
}
else{
if(input != NULL){
fatal("only one input file can be specified");
usage();
}
input = argv[i];
}
}
if(input == NULL){
error("no input file specified");
usage();
}
if(replaces != NULL && output == NULL)
fatal("output file must be specified via -o <filename> when "
"replacing a section");
if(extracts == NULL && replaces == NULL){
error("no -extract or -replace options specified");
usage();
}
map_input();
if(extracts != NULL)
extract_sections();
if(replaces != NULL)
replace_sections();
return(0);
}
/*
* map_input maps the input file into memory. The address it is mapped at is
* left in input_addr and the size is left in input_size. The input file is
* checked to be an object file and that the headers are checked to be correct
* enough to loop through them. The pointer to the mach header is left in mhp
* and the pointer to the load commands is left in load_commands.
*/
static
void
map_input(void)
{
int fd;
uint32_t i, magic, mh_sizeofcmds;
struct stat stat_buf;
struct load_command l, *lcp;
struct segment_command *sgp;
struct segment_command_64 *sgp64;
struct section *sp;
struct section_64 *sp64;
struct symtab_command *stp;
struct symseg_command *ssp;
/* Open the input file and map it in */
if((fd = open(input, O_RDONLY)) == -1)
system_fatal("can't open input file: %s", input);
if(fstat(fd, &stat_buf) == -1)
system_fatal("Can't stat input file: %s", input);
input_size = stat_buf.st_size;
input_mode = stat_buf.st_mode;
input_addr = mmap(0, input_size, PROT_READ|PROT_WRITE,
MAP_FILE|MAP_PRIVATE, fd, 0);
if((intptr_t)input_addr == -1)
system_error("Can't map input file: %s", input);
close(fd);
if(sizeof(uint32_t) > input_size)
fatal("truncated or malformed object (mach header would extend "
"past the end of the file) in: %s", input);
magic = *(uint32_t *)input_addr;
#ifdef __BIG_ENDIAN__
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if(magic == FAT_MAGIC || magic == FAT_MAGIC_64)
#endif /* __BIG_ENDIAN__ */
#ifdef __LITTLE_ENDIAN__
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if(magic == SWAP_INT(FAT_MAGIC) || magic == SWAP_INT(FAT_MAGIC_64))
#endif /* __LITTLE_ENDIAN__ */
fatal("file: %s is a fat file (%s only operates on Mach-O files, "
"use lipo(1) on it to get a Mach-O file)", input, progname);
mh_ncmds = 0;
mh_sizeofcmds = 0;
host_byte_sex = get_host_byte_sex();
if(magic == SWAP_INT(MH_MAGIC) || magic == MH_MAGIC){
if(sizeof(struct mach_header) > input_size)
fatal("truncated or malformed object (mach header would extend "
"past the end of the file) in: %s", input);
mhp = (struct mach_header *)input_addr;
if(magic == SWAP_INT(MH_MAGIC)){
swapped = TRUE;
target_byte_sex = host_byte_sex == BIG_ENDIAN_BYTE_SEX ?
LITTLE_ENDIAN_BYTE_SEX : BIG_ENDIAN_BYTE_SEX;
swap_mach_header(mhp, host_byte_sex);
}
else{
swapped = FALSE;
target_byte_sex = host_byte_sex;
}
if(mhp->sizeofcmds + sizeof(struct mach_header) > input_size)
fatal("truncated or malformed object (load commands would "
"extend past the end of the file) in: %s", input);
load_commands = (struct load_command *)((char *)input_addr +
sizeof(struct mach_header));
mh_ncmds = mhp->ncmds;
mh_sizeofcmds = mhp->sizeofcmds;
}
else if(magic == SWAP_INT(MH_MAGIC_64) || magic == MH_MAGIC_64){
if(sizeof(struct mach_header_64) > input_size)
fatal("truncated or malformed object (mach header would extend "
"past the end of the file) in: %s", input);
mhp64 = (struct mach_header_64 *)input_addr;
if(magic == SWAP_INT(MH_MAGIC_64)){
swapped = TRUE;
target_byte_sex = host_byte_sex == BIG_ENDIAN_BYTE_SEX ?
LITTLE_ENDIAN_BYTE_SEX : BIG_ENDIAN_BYTE_SEX;
swap_mach_header_64(mhp64, host_byte_sex);
}
else{
swapped = FALSE;
target_byte_sex = host_byte_sex;
}
if(mhp64->sizeofcmds + sizeof(struct mach_header_64) > input_size)
fatal("truncated or malformed object (load commands would "
"extend past the end of the file) in: %s", input);
load_commands = (struct load_command *)((char *)input_addr +
sizeof(struct mach_header_64));
mh_ncmds = mhp64->ncmds;
mh_sizeofcmds = mhp64->sizeofcmds;
}
else
fatal("bad magic number (file is not a Mach-O file) in: %s", input);
lcp = load_commands;
for(i = 0; i < mh_ncmds; i++){
l = *lcp;
if(swapped)
swap_load_command(&l, host_byte_sex);
if(l.cmdsize % sizeof(uint32_t) != 0)
error("load command %u size not a multiple of "
"sizeof(uint32_t) in: %s", i, input);
if(l.cmdsize <= 0)
fatal("load command %u size is less than or equal to zero "
"in: %s", i, input);
if((char *)lcp + l.cmdsize >
(char *)load_commands + mh_sizeofcmds)
fatal("load command %u extends past end of all load commands "
"in: %s", i, input);
switch(l.cmd){
case LC_SEGMENT:
sgp = (struct segment_command *)lcp;
sp = (struct section *)((char *)sgp +
sizeof(struct segment_command));
if(swapped)
swap_segment_command(sgp, host_byte_sex);
if(swapped)
swap_section(sp, sgp->nsects, host_byte_sex);
break;
case LC_SEGMENT_64:
sgp64 = (struct segment_command_64 *)lcp;
sp64 = (struct section_64 *)((char *)sgp64 +
sizeof(struct segment_command_64));
if(swapped)
swap_segment_command_64(sgp64, host_byte_sex);
if(swapped)
swap_section_64(sp64, sgp64->nsects, host_byte_sex);
break;
case LC_SYMTAB:
stp = (struct symtab_command *)lcp;
if(swapped)
swap_symtab_command(stp, host_byte_sex);
break;
case LC_SYMSEG:
ssp = (struct symseg_command *)lcp;
if(swapped)
swap_symseg_command(ssp, host_byte_sex);
break;
default:
*lcp = l;
break;
}
lcp = (struct load_command *)((char *)lcp + l.cmdsize);
}
}
/*
* This routine extracts the sections in the extracts list from the input file
* and writes then to the file specified in the list.
*/
static
void
extract_sections(void)
{
uint32_t i, j, errors;
struct load_command *lcp;
struct segment_command *sgp;
struct segment_command_64 *sgp64;
struct section *sp;
struct section_64 *sp64;
struct extract *ep;
lcp = load_commands;
for(i = 0; i < mh_ncmds; i++){
if(lcp->cmd == LC_SEGMENT){
sgp = (struct segment_command *)lcp;
sp = (struct section *)((char *)sgp +
sizeof(struct segment_command));
for(j = 0; j < sgp->nsects; j++){
extract_section(sp->segname, sp->sectname, sp->flags,
sp->offset, sp->size);
sp++;
}
}
else if(lcp->cmd == LC_SEGMENT_64){
sgp64 = (struct segment_command_64 *)lcp;
sp64 = (struct section_64 *)((char *)sgp64 +
sizeof(struct segment_command_64));
for(j = 0; j < sgp64->nsects; j++){
extract_section(sp64->segname, sp64->sectname, sp64->flags,
sp64->offset, sp64->size);
sp64++;
}
}
lcp = (struct load_command *)((char *)lcp + lcp->cmdsize);
}
errors = 0;
ep = extracts;
while(ep != NULL){
if(ep->found == 0){
error("section (%s,%s) not found in: %s", ep->segname,
ep->sectname, input);
errors = 1;
}
ep = ep->next;
}
if(errors != 0)
exit(1);
}
static
void
extract_section(
char *segname,
char *sectname,
uint32_t flags,
uint32_t offset,
uint32_t size)
{
struct extract *ep;
int fd;
ep = extracts;
while(ep != NULL){
if(ep->found == 0 &&
strncmp(ep->segname, segname, 16) == 0 &&
strncmp(ep->sectname, sectname, 16) == 0){
if(flags == S_ZEROFILL || flags == S_THREAD_LOCAL_ZEROFILL)
fatal("meaningless to extract zero fill "
"section (%s,%s) in: %s", segname,
sectname, input);
if(offset + size > input_size)
fatal("truncated or malformed object (section "
"contents of (%s,%s) extends past the "
"end of the file) in: %s", segname,
sectname, input);
if((fd = open(ep->filename, O_WRONLY | O_CREAT |
O_TRUNC, 0666)) == -1)
system_fatal("can't create: %s", ep->filename);
if(write(fd, (char *)input_addr + offset,
size) != (int)size)
system_fatal("can't write: %s", ep->filename);
if(close(fd) == -1)
system_fatal("can't close: %s", ep->filename);
ep->found = 1;
}
ep = ep->next;
}
}
static
void
replace_sections(void)
{
uint32_t i, j, k, l, errors, nsegs, nsects, high_reloc_seg;
uint32_t low_noreloc_seg, high_noreloc_seg, low_linkedit;
uint32_t oldoffset, newoffset, oldsectsize, newsectsize;
uint64_t oldvmaddr, newvmaddr;
struct load_command lc, *lcp;
struct segment_command *sgp, *linkedit_sgp;
struct segment_command_64 *sgp64, *linkedit_sgp64;
struct section *sp;
struct section_64 *sp64;
struct symtab_command *stp;
struct symseg_command *ssp;
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struct dysymtab_command* dstp;
struct replace *rp;
struct stat stat_buf;
int outfd, sectfd;
char *sect_addr;
vm_address_t pad_addr;
uint32_t size;
kern_return_t r;
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enum bool no_seg_resize;
errors = 0;
high_reloc_seg = 0;
low_noreloc_seg = input_size;
high_noreloc_seg = 0;
low_linkedit = input_size;
nsegs = 0;
segs = allocate(mh_ncmds * sizeof(struct rep_seg));
bzero(segs, mh_ncmds * sizeof(struct rep_seg));
nsects = 0;
stp = NULL;
ssp = NULL;
linkedit_sgp = NULL;
linkedit_sgp64 = NULL;
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dstp = NULL;
no_seg_resize = FALSE;
/*
* First pass over the load commands and determine if the file is laided
* out in an order that the specified sections can be replaced. Also
* determine if the specified sections exist in the input file and if
* it is marked with no relocation so it can be replaced.
*/
lcp = load_commands;
for(i = 0; i < mh_ncmds; i++){
switch(lcp->cmd){
case LC_SEGMENT:
sgp = (struct segment_command *)lcp;
sp = (struct section *)((char *)sgp +
sizeof(struct segment_command));
segs[nsegs++].sgp = sgp;
nsects += sgp->nsects;
if(strcmp(sgp->segname, SEG_LINKEDIT) != 0){
if(sgp->flags & SG_NORELOC){
if(sgp->filesize != 0){
if(sgp->fileoff + sgp->filesize > high_noreloc_seg)
high_noreloc_seg = sgp->fileoff + sgp->filesize;
if(sgp->fileoff < low_noreloc_seg)
low_noreloc_seg = sgp->fileoff;
}
}
else{
if(sgp->filesize != 0 &&
sgp->fileoff + sgp->filesize > high_reloc_seg)
high_reloc_seg = sgp->fileoff + sgp->filesize;
}
}
else{
if(linkedit_sgp != NULL)
fatal("more than one " SEG_LINKEDIT " segment found "
"in: %s", input);
linkedit_sgp = sgp;
}
for(j = 0; j < sgp->nsects; j++){
if(sp->nreloc != 0 && sp->reloff < low_linkedit)
low_linkedit = sp->reloff;
search_for_replace_section(sp->segname, sp->sectname,
sgp->flags, sp->flags, sp->offset, sp->size);
sp++;
}
break;
case LC_SEGMENT_64:
sgp64 = (struct segment_command_64 *)lcp;
sp64 = (struct section_64 *)((char *)sgp64 +
sizeof(struct segment_command_64));
segs[nsegs++].sgp64 = sgp64;
nsects += sgp64->nsects;
if(strcmp(sgp64->segname, SEG_LINKEDIT) != 0){
if(sgp64->flags & SG_NORELOC){
if(sgp64->filesize != 0){
if(sgp64->fileoff + sgp64->filesize >
high_noreloc_seg)
high_noreloc_seg = sgp64->fileoff +
sgp64->filesize;
if(sgp64->fileoff < low_noreloc_seg)
low_noreloc_seg = sgp64->fileoff;
}
}
else{
if(sgp64->filesize != 0 &&
sgp64->fileoff + sgp64->filesize > high_reloc_seg)
high_reloc_seg = sgp64->fileoff + sgp64->filesize;
}
}
else{
if(linkedit_sgp64 != NULL)
fatal("more than one " SEG_LINKEDIT " segment found "
"in: %s", input);
linkedit_sgp64 = sgp64;
}
for(j = 0; j < sgp64->nsects; j++){
if(sp64->nreloc != 0 && sp64->reloff < low_linkedit)
low_linkedit = sp64->reloff;
search_for_replace_section(sp64->segname, sp64->sectname,
sgp64->flags, sp64->flags, sp64->offset, sp64->size);
sp64++;
}
break;
case LC_SYMTAB:
if(stp != NULL)
fatal("more than one symtab_command found in: %s", input);
stp = (struct symtab_command *)lcp;
if(stp->nsyms != 0 && stp->symoff < low_linkedit)
low_linkedit = stp->symoff;
if(stp->strsize != 0 && stp->stroff < low_linkedit)
low_linkedit = stp->stroff;
break;
case LC_DYSYMTAB:
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if (dstp != NULL)
fatal("more than one dysymtab_command found in: %s", input);
no_seg_resize = TRUE;
dstp = (struct dysymtab_command*)lcp;
if (dstp->tocoff != 0 && dstp->tocoff < low_linkedit)
low_linkedit = dstp->tocoff;
if (dstp->modtaboff != 0 && dstp->modtaboff < low_linkedit)
low_linkedit = dstp->modtaboff;
if (dstp->extrefsymoff != 0 &&
dstp->extrefsymoff < low_linkedit)
low_linkedit = dstp->extrefsymoff;
if (dstp->indirectsymoff != 0 &&
dstp->indirectsymoff < low_linkedit)
low_linkedit = dstp->indirectsymoff;
if (dstp->extreloff != 0 && dstp->extreloff < low_linkedit)
low_linkedit = dstp->extreloff;
if (dstp->locreloff != 0 && dstp->locreloff < low_linkedit)
low_linkedit = dstp->locreloff;
break;
case LC_SYMSEG:
if(ssp != NULL)
fatal("more than one symseg_command found in: %s", input);
ssp = (struct symseg_command *)lcp;
if(ssp->size != 0 && ssp->offset < low_linkedit)
low_linkedit = ssp->offset;
break;
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case LC_CODE_SIGNATURE:
case LC_SEGMENT_SPLIT_INFO:
case LC_FUNCTION_STARTS:
case LC_DATA_IN_CODE:
case LC_DYLIB_CODE_SIGN_DRS:
case LC_LINKER_OPTIMIZATION_HINT:
{
struct linkedit_data_command* ldcp =
(struct linkedit_data_command*)lcp;
if (ldcp->dataoff != 0 && ldcp->dataoff < low_linkedit)
low_linkedit = ldcp->dataoff;
}
break;
case LC_DYLD_INFO:
case LC_DYLD_INFO_ONLY:
{
struct dyld_info_command* dicp =
(struct dyld_info_command*)lcp;
no_seg_resize = TRUE;
if (dicp->rebase_off != 0 &&
dicp->rebase_off < low_linkedit)
low_linkedit = dicp->rebase_off;
if (dicp->bind_off != 0 && dicp->bind_off < low_linkedit)
low_linkedit = dicp->bind_off;
if (dicp->weak_bind_off != 0 &&
dicp->weak_bind_off < low_linkedit)
low_linkedit = dicp->weak_bind_off;
if (dicp->lazy_bind_off != 0 &&
dicp->lazy_bind_off < low_linkedit)
low_linkedit = dicp->lazy_bind_off;
if (dicp->export_off != 0 &&
dicp->export_off < low_linkedit)
low_linkedit = dicp->export_off;
}
break;
case LC_THREAD:
case LC_UNIXTHREAD:
case LC_LOADFVMLIB:
case LC_IDFVMLIB:
case LC_IDENT:
case LC_FVMFILE:
case LC_PREPAGE:
case LC_LOAD_DYLIB:
case LC_LOAD_WEAK_DYLIB:
case LC_REEXPORT_DYLIB:
case LC_LOAD_UPWARD_DYLIB:
case LC_ID_DYLIB:
case LC_LOAD_DYLINKER:
case LC_ID_DYLINKER:
case LC_DYLD_ENVIRONMENT:
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case LC_PREBOUND_DYLIB:
case LC_ROUTINES:
case LC_SUB_FRAMEWORK:
case LC_SUB_UMBRELLA:
case LC_SUB_CLIENT:
case LC_SUB_LIBRARY:
case LC_TWOLEVEL_HINTS:
case LC_PREBIND_CKSUM:
case LC_ROUTINES_64:
case LC_UUID:
case LC_RPATH:
case LC_LAZY_LOAD_DYLIB:
case LC_ENCRYPTION_INFO:
case LC_ENCRYPTION_INFO_64:
case LC_VERSION_MIN_MACOSX:
case LC_VERSION_MIN_IPHONEOS:
case LC_VERSION_MIN_TVOS:
case LC_VERSION_MIN_WATCHOS:
case LC_NOTE:
case LC_BUILD_VERSION:
case LC_MAIN:
case LC_SOURCE_VERSION:
case LC_LINKER_OPTION:
break;
default:
error("unknown load command %u (result maybe bad)", i);
break;
}
lcp = (struct load_command *)((char *)lcp + lcp->cmdsize);
}
rp = replaces;
while(rp != NULL){
if(rp->found == 0){
error("section (%s,%s) not found in: %s", rp->segname,
rp->sectname, input);
errors = 1;
}
else{
if(stat(rp->filename, &stat_buf) == -1){
system_error("Can't stat file: %s to replace section "
"(%s,%s) with", rp->filename, rp->segname,
rp->sectname);
errors = 1;
}
rp->size = stat_buf.st_size;
}
rp = rp->next;
}
if(errors != 0)
exit(1);
if(high_reloc_seg > low_noreloc_seg ||
high_reloc_seg > low_linkedit ||
high_noreloc_seg > low_linkedit)
fatal("contents of input file: %s not in an order that the "
"specified sections can be replaced by this program", input);
qsort(segs, nsegs, sizeof(struct rep_seg),
(int (*)(const void *, const void *))cmp_qsort);
sects = allocate(nsects * sizeof(struct rep_sect));
bzero(sects, nsects * sizeof(struct rep_sect));
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/*
* Set the pagesize to match that of the input file. Note that we cannot
* assume a single pagesize across all Mach-O files.
*/
if(mhp != NULL)
pagesize = 1 << get_align(mhp, load_commands, input_size, input,
swapped);
else
pagesize = 1 << get_align_64(mhp64, load_commands, input_size,
input, swapped);
/*
* First go through the segments and adjust the segment offsets, sizes
* and addresses without adjusting the offset to the relocation entries.
* This program can only handle object files that have contigious
* address spaces starting at zero and that the offsets in the file for
* the contents of the segments also being contiguious and in the same
* order as the vmaddresses.
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*
* Note that in a modern Mach-O file, segedit can resize individual
* sections, but their overall segment sizes cannot change. There once
* was a time in early NeXTSTEP when that was not true...
*/
oldvmaddr = 0;
newvmaddr = 0;
if(nsegs > 1){
if(segs[0].sgp != NULL)
oldoffset = segs[0].sgp->fileoff;
else
oldoffset = segs[0].sgp64->fileoff;
}
else
oldoffset = 0;
newoffset = 0;
k = 0;
for(i = 0; i < nsegs; i++){
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if(segs[i].sgp != NULL){ /* process the 32-bit file */
/* verify the segment vmaddrs are contiguous */
if(segs[i].sgp->vmaddr != oldvmaddr)
fatal("addresses of input file: %s not in an order that "
"the specified sections can be replaced by this "
"program", input);
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/*
* initialize the rep_seg struct's filesize, vmsize, and vmaddr
* fields. update the vmaddr if this file is resizeable (hint:
* it's not).
*/
segs[i].filesize = segs[i].sgp->filesize;
segs[i].vmsize = segs[i].sgp->vmsize;
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if (no_seg_resize == FALSE) {
segs[i].sgp->vmaddr = newvmaddr;
} else {
if(segs[i].sgp->vmaddr != newvmaddr)
fatal("input file: %s segment %.16s vmaddr cannot be "
"repositioned",
input, segs[i].sgp->segname);
}
if(segs[i].sgp->filesize != 0){
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/* verify the segment fileoffs are contiguous */
if(segs[i].sgp->fileoff != oldoffset)
fatal("segment offsets of input file: %s not in an "
"order that the specified sections can be "
"replaced by this program", input);
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/*
* initialize the rep_seg struct's fileoff field, and adjust
* it if this file is resizeable (hint: still no.)
*/
segs[i].fileoff = segs[i].sgp->fileoff;
if(strcmp(segs[i].sgp->segname, SEG_LINKEDIT) != 0 ||
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i != nsegs - 1) {
if (no_seg_resize == FALSE) {
segs[i].sgp->fileoff = newoffset;
} else {
if (segs[i].sgp->fileoff != newoffset) {
fatal("input file: %s segment %.16s fileoff "
"cannot be repositioned",
input, segs[i].sgp->segname);
}
}
}
sp = (struct section *)((char *)(segs[i].sgp) +
sizeof(struct segment_command));
oldsectsize = 0;
newsectsize = 0;
if(segs[i].sgp->flags & SG_NORELOC){
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/*
* this segment contains sections that can be replaced.
* loop over the sections and record the new offsets
* and sizes for the replaced content.
*
* recall that if no_seg_resize is true the sections
* cannot spill beyond the segment boundary.
*/
for(j = 0; j < segs[i].sgp->nsects; j++){
sects[k + j].sp = sp;
sects[k + j].offset = sp->offset;
oldsectsize += sp->size;
rp = replaces;
while(rp != NULL){
if(strncmp(rp->segname, sp->segname,
sizeof(sp->segname)) == 0 &&
strncmp(rp->sectname, sp->sectname,
sizeof(sp->sectname)) == 0){
sects[k + j].rp = rp;
segs[i].modified = 1;
sp->size = rnd(rp->size, 1 << sp->align);
break;
}
rp = rp->next;
}
sp->offset = newoffset + newsectsize;
sp->addr = newvmaddr + newsectsize;
newsectsize += sp->size;
sp++;
}
if(strcmp(segs[i].sgp->segname, SEG_LINKEDIT) != 0 ||
i != nsegs - 1){
if(segs[i].sgp->filesize != rnd(oldsectsize,
pagesize))
fatal("contents of input file: %s not in a "
"format that the specified sections can "
"be replaced by this program", input);
segs[i].padsize =
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segs[i].sgp->filesize - newsectsize;
if (no_seg_resize == FALSE) {
segs[i].sgp->filesize =
rnd(newsectsize, pagesize);
segs[i].sgp->vmsize = rnd(newsectsize,
pagesize);
} else {
if (segs[i].sgp->filesize !=
rnd(newsectsize, pagesize)) {
fatal("input file: %s segment %.16s "
"cannot be resized (filesize %u => "
"%llu)",
input, segs[i].sgp->segname,
segs[i].sgp->filesize,
rnd(newsectsize, pagesize));
}
if (segs[i].sgp->vmsize !=
rnd(newsectsize, pagesize)) {
fatal("input file: %s segment %.16s "
"cannot be resized (vmsize %u => "
"%llu)",
input, segs[i].sgp->segname,
segs[i].sgp->vmsize,
rnd(newsectsize, pagesize));
}
}
}
}
if(strcmp(segs[i].sgp->segname, SEG_LINKEDIT) != 0 ||
i != nsegs - 1){
oldoffset += segs[i].filesize;
newoffset += segs[i].sgp->filesize;
}
}
oldvmaddr += segs[i].vmsize;
newvmaddr += segs[i].sgp->vmsize;
k += segs[i].sgp->nsects;
}
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else { /* process the 64-bit file */
/* verify the segment vmaddrs are contiguous */
if(segs[i].sgp64->vmaddr != oldvmaddr)
fatal("addresses of input file: %s not in an order that "
"the specified sections can be replaced by this "
"program", input);
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/*
* initialize the rep_seg struct's filesize, vmsize, and vmaddr
* fields. update the vmaddr if this file is resizeable (hint:
* it's not).
*/
segs[i].filesize = segs[i].sgp64->filesize;
segs[i].vmsize = segs[i].sgp64->vmsize;
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if (no_seg_resize == FALSE) {
segs[i].sgp64->vmaddr = newvmaddr;
} else {
if(segs[i].sgp64->vmaddr != newvmaddr)
fatal("input file: %s segment %.16s vmaddr cannot be "
"repositioned", input, segs[i].sgp64->segname);
}
if(segs[i].sgp64->filesize != 0){
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/* verify the segment fileoffs are contiguous */
if(segs[i].sgp64->fileoff != oldoffset)
fatal("segment offsets of input file: %s not in an "
"order that the specified sections can be "
"replaced by this program", input);
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/*
* initialize the rep_seg struct's fileoff field, and adjust
* it if this file is resizeable (hint: still no.)
*/
segs[i].fileoff = segs[i].sgp64->fileoff;
if(strcmp(segs[i].sgp64->segname, SEG_LINKEDIT) != 0 ||
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i != nsegs - 1) {
if (no_seg_resize == FALSE) {
segs[i].sgp64->fileoff = newoffset;
} else {
if (segs[i].sgp64->fileoff != newoffset) {
fatal("input file: %s segment %.16s fileoff "
"cannot be repositioned",
input, segs[i].sgp64->segname);
}
}
}
sp64 = (struct section_64 *)((char *)(segs[i].sgp64) +
sizeof(struct segment_command_64));
oldsectsize = 0;
newsectsize = 0;
if(segs[i].sgp64->flags & SG_NORELOC){
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/*
* this segment contains sections that can be replaced.
* loop over the sections and record the new offsets
* and sizes for the replaced content.
*
* recall that if no_seg_resize is true the sections
* cannot spill beyond the segment boundary.
*/
for(j = 0; j < segs[i].sgp64->nsects; j++){
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sects[k + j].sp64 = sp64;
sects[k + j].offset = sp64->offset;
oldsectsize += sp64->size;
rp = replaces;
while(rp != NULL){
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if(strncmp(rp->segname, sp64->segname,
sizeof(sp64->segname)) == 0 &&
strncmp(rp->sectname, sp64->sectname,
sizeof(sp64->sectname)) == 0){
sects[k + j].rp = rp;
segs[i].modified = 1;
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sp64->size =
rnd(rp->size, 1 << sp64->align);
break;
}
rp = rp->next;
}
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sp64->offset = newoffset + newsectsize;
sp64->addr = newvmaddr + newsectsize;
newsectsize += sp64->size;
sp64++;
}
if(strcmp(segs[i].sgp64->segname, SEG_LINKEDIT) != 0 ||
i != nsegs - 1){
if(segs[i].sgp64->filesize != rnd(oldsectsize,
pagesize))
fatal("contents of input file: %s not in a "
"format that the specified sections can "
"be replaced by this program", input);
segs[i].padsize =
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segs[i].sgp64->filesize - newsectsize;
if (no_seg_resize == FALSE) {
segs[i].sgp64->filesize =
rnd(newsectsize, pagesize);
segs[i].sgp64->vmsize =
rnd(newsectsize, pagesize);
} else {
if (segs[i].sgp64->filesize !=
rnd(newsectsize, pagesize)) {
fatal("input file: %s segment %.16s "
"cannot be resized (filesize %llu => "
"%llu)",
input, segs[i].sgp64->segname,
segs[i].sgp64->filesize,
rnd(newsectsize, pagesize));
}
if (segs[i].sgp64->vmsize !=
rnd(newsectsize, pagesize)) {
fatal("input file: %s segment %.16s "
"cannot be resized (vmsize %llu => "
"%llu)",
input, segs[i].sgp64->segname,
segs[i].sgp64->vmsize,
rnd(newsectsize, pagesize));
}
}
}
}
if(strcmp(segs[i].sgp64->segname, SEG_LINKEDIT) != 0 ||
i != nsegs - 1){
oldoffset += segs[i].filesize;
newoffset += segs[i].sgp64->filesize;
}
}
oldvmaddr += segs[i].vmsize;
newvmaddr += segs[i].sgp64->vmsize;
k += segs[i].sgp64->nsects;
}
}
/*
* Now update the offsets to the linkedit information.
*/
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if (no_seg_resize == FALSE) {
if(oldoffset != low_linkedit)
fatal("contents of input file: %s not in an order that the "
"specified sections can be replaced by this program",
input);
for(i = 0; i < nsegs; i++){
if(segs[i].sgp != NULL){
sp = (struct section *)((char *)(segs[i].sgp) +
sizeof(struct segment_command));
for(j = 0; j < segs[i].sgp->nsects; j++){
if(sp->nreloc != 0)
sp->reloff += newoffset - oldoffset;
sp++;
}
}
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else{
sp64 = (struct section_64 *)((char *)(segs[i].sgp64) +
sizeof(struct segment_command_64));
for(j = 0; j < segs[i].sgp64->nsects; j++){
if(sp64->nreloc != 0)
sp64->reloff += newoffset - oldoffset;
sp64++;
}
}
}
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if(stp != NULL){
if(stp->nsyms != 0)
stp->symoff += newoffset - oldoffset;
if(stp->strsize != 0)
stp->stroff += newoffset - oldoffset;
}
if(ssp != NULL){
if(ssp->size != 0)
ssp->offset += newoffset - oldoffset;
}
if(linkedit_sgp != NULL){
linkedit_sgp->fileoff += newoffset - oldoffset;
}
if(linkedit_sgp64 != NULL){
linkedit_sgp64->fileoff += newoffset - oldoffset;
}
}
/*
* Now write the new file by writing the header and modified load
* commands, then the segments with any new sections and finally
* the link edit info.
*/
if((outfd = open(output, O_CREAT | O_WRONLY | O_TRUNC ,input_mode))
== -1)
system_fatal("can't create output file: %s", output);
if((r = vm_allocate(mach_task_self(), &pad_addr, pagesize, 1)) !=
KERN_SUCCESS)
mach_fatal(r, "vm_allocate() failed");
k = 0;
for(i = 0; i < nsegs; i++){
if(segs[i].modified){
if(segs[i].sgp != NULL){
for(j = 0; j < segs[i].sgp->nsects; j++){
/* if the section is replaced write the replaced
section */
sp = sects[k + j].sp;
rp = sects[k + j].rp;
if(rp != NULL){
if((sectfd = open(rp->filename, O_RDONLY)) == -1)
system_fatal("can't open file: %s to replace "
"section (%s,%s) with", rp->filename,
rp->segname, rp->sectname);
sect_addr = mmap(0, rp->size, PROT_READ|PROT_WRITE,
MAP_FILE|MAP_PRIVATE, sectfd, 0);
if((intptr_t)sect_addr == -1)
system_error("Can't map file: %s",rp->filename);
for(l = rp->size + 1; l < sp->size; l++)
*((char *)sect_addr + l) = '\0';
if(write(outfd, (char *)sect_addr,sp->size) !=
sp->size)
system_fatal("can't write new section contents "
"for section (%s,%s) to output file: %s",
rp->segname, rp->sectname, output);
if(close(sectfd) == -1)
system_error("can't close file: %s to replace "
"section (%s,%s) with", rp->filename,
rp->segname, rp->sectname);
if((r = vm_deallocate(mach_task_self(),
(vm_address_t)sect_addr,
rp->size)) != KERN_SUCCESS)
mach_fatal(r, "Can't deallocate memory for "
"mapped file: %s", rp->filename);
}
else{
/* write the original section */
if(sects[k + j].offset + sp->size > input_size)
fatal("truncated or malformed object file: %s "
"(section (%.16s,%.16s) extends past the "
"end of the file)",input, sp->segname,
sp->sectname);
if(write(outfd,(char *)input_addr +
sects[k + j].offset,
sp->size) != sp->size)
system_fatal("can't write section contents for "
"section (%s,%s) to output file: %s",
rp->segname, rp->sectname, output);
}
sp++;
}
/* write the segment padding */
if(write(outfd, (char *)pad_addr, segs[i].padsize) !=
segs[i].padsize)
system_fatal("can't write segment padding for segment "
"%s to output file: %s", segs[i].sgp->segname,
output);
}
else{
for(j = 0; j < segs[i].sgp64->nsects; j++){
/* if the section is replaced write the replaced
section */
sp64 = sects[k + j].sp64;
rp = sects[k + j].rp;
if(rp != NULL){
if((sectfd = open(rp->filename, O_RDONLY)) == -1)
system_fatal("can't open file: %s to replace "
"section (%s,%s) with", rp->filename,
rp->segname, rp->sectname);
sect_addr = mmap(0, rp->size, PROT_READ|PROT_WRITE,
MAP_FILE|MAP_PRIVATE, sectfd, 0);
if((intptr_t)sect_addr == -1)
system_error("Can't map file: %s",rp->filename);
for(l = rp->size + 1; l < sp64->size; l++)
*((char *)sect_addr + l) = '\0';
if(write(outfd, (char *)sect_addr,sp64->size) !=
sp64->size)
system_fatal("can't write new section contents "
"for section (%s,%s) to output file: %s",
rp->segname, rp->sectname, output);
if(close(sectfd) == -1)
system_error("can't close file: %s to replace "
"section (%s,%s) with", rp->filename,
rp->segname, rp->sectname);
if((r = vm_deallocate(mach_task_self(),
(vm_address_t)sect_addr,
rp->size)) != KERN_SUCCESS)
mach_fatal(r, "Can't deallocate memory for "
"mapped file: %s", rp->filename);
}
else{
/* write the original section */
if(sects[k + j].offset + sp64->size > input_size)
fatal("truncated or malformed object file: %s "
"(section (%.16s,%.16s) extends past the "
"end of the file)",input, sp64->segname,
sp64->sectname);
if(write(outfd,(char *)input_addr +
sects[k + j].offset,
sp64->size) != sp64->size)
system_fatal("can't write section contents for "
"section (%s,%s) to output file: %s",
rp->segname, rp->sectname, output);
}
sp64++;
}
/* write the segment padding */
if(write(outfd, (char *)pad_addr, segs[i].padsize) !=
segs[i].padsize)
system_fatal("can't write segment padding for segment "
"%s to output file: %s", segs[i].sgp64->segname,
output);
}
}
else{
/* write the original segment */
if(segs[i].sgp != NULL){
if(strcmp(segs[i].sgp->segname, SEG_LINKEDIT) != 0 ||
i != nsegs - 1){
if(segs[i].fileoff + segs[i].sgp->filesize > input_size)
fatal("truncated or malformed object file: %s "
"(segment: %s extends past the end of "
"the file)", input, segs[i].sgp->segname);
if(write(outfd, (char *)input_addr + segs[i].fileoff,
segs[i].sgp->filesize) != segs[i].sgp->filesize)
system_fatal("can't write segment contents for "
"segment: %s to output file: %s",
segs[i].sgp->segname, output);
}
}
else{
if(strcmp(segs[i].sgp64->segname, SEG_LINKEDIT) != 0 ||
i != nsegs - 1){
if(segs[i].fileoff + segs[i].sgp64->filesize >
input_size)
fatal("truncated or malformed object file: %s "
"(segment: %s extends past the end of "
"the file)", input, segs[i].sgp64->segname);
if(write(outfd, (char *)input_addr + segs[i].fileoff,
segs[i].sgp64->filesize) != segs[i].sgp64->filesize)
system_fatal("can't write segment contents for "
"segment: %s to output file: %s",
segs[i].sgp64->segname, output);
}
}
}
if(segs[i].sgp != NULL)
k += segs[i].sgp->nsects;
else
k += segs[i].sgp64->nsects;
}
/* write the linkedit info */
size = input_size - low_linkedit;
if(write(outfd, (char *)input_addr + low_linkedit, size) != size)
system_fatal("can't write link edit information to output file: %s",
output);
lseek(outfd, 0, L_SET);
if(mhp != NULL)
size = sizeof(struct mach_header) + mhp->sizeofcmds;
else
size = sizeof(struct mach_header_64) + mhp64->sizeofcmds;
if(swapped){
lcp = load_commands;
for(i = 0; i < mh_ncmds; i++){
lc = *lcp;
switch(lcp->cmd){
case LC_SEGMENT:
sgp = (struct segment_command *)lcp;
sp = (struct section *)((char *)sgp +
sizeof(struct segment_command));
swap_section(sp, sgp->nsects, host_byte_sex);
swap_segment_command(sgp, host_byte_sex);
break;
case LC_SEGMENT_64:
sgp64 = (struct segment_command_64 *)lcp;
sp64 = (struct section_64 *)((char *)sgp64 +
sizeof(struct segment_command_64));
swap_section_64(sp64, sgp64->nsects, host_byte_sex);
swap_segment_command_64(sgp64, host_byte_sex);
break;
case LC_SYMTAB:
stp = (struct symtab_command *)lcp;
swap_symtab_command(stp, host_byte_sex);
break;
case LC_SYMSEG:
ssp = (struct symseg_command *)lcp;
swap_symseg_command(ssp, host_byte_sex);
break;
default:
swap_load_command(lcp, host_byte_sex);
break;
}
lcp = (struct load_command *)((char *)lcp + lc.cmdsize);
}
if(mhp != NULL)
swap_mach_header(mhp, host_byte_sex);
else
swap_mach_header_64(mhp64, host_byte_sex);
}
if(write(outfd, input_addr, size) != size)
system_fatal("can't write headers to output file: %s", output);
if(close(outfd) == -1)
system_fatal("can't close output file: %s", output);
}
static
void
search_for_replace_section(
char *segname,
char *sectname,
uint32_t seg_flags,
uint32_t sect_flags,
uint32_t offset,
uint32_t size)
{
struct replace *rp;
rp = replaces;
while(rp != NULL){
if(rp->found == 0 &&
strncmp(rp->segname, segname, 16) == 0 &&
strncmp(rp->sectname, sectname, 16) == 0){
if(sect_flags == S_ZEROFILL ||
sect_flags == S_THREAD_LOCAL_ZEROFILL){
error("can't replace zero fill section (%.16s,"
"%.16s) in: %s", segname,
sectname, input);
errors = 1;
}
if((seg_flags & SG_NORELOC) == 0){
error("can't replace section (%.16s,%.16s) "
"in: %s because it requires relocation",
segname, sectname, input);
errors = 1;
}
if(offset + size > input_size)
fatal("truncated or malformed object (section "
"contents of (%.16s,%.16s) extends "
"past the end of the file) in: %s",
segname, sectname, input);
rp->found = 1;
}
rp = rp->next;
}
}
/*
* Function for qsort for comparing segment's vmaddrs
*/
static
int
cmp_qsort(
const struct rep_seg *seg1,
const struct rep_seg *seg2)
{
if(seg1->sgp != NULL){
if(seg1->sgp->vmaddr > seg2->sgp->vmaddr)
return(1);
if(seg1->sgp->vmaddr < seg2->sgp->vmaddr)
return(-1);
/* seg1->sgp->vmaddr == seg2->sgp->vmaddr */
return(0);
}
else{
if(seg1->sgp64->vmaddr > seg2->sgp64->vmaddr)
return(1);
if(seg1->sgp64->vmaddr < seg2->sgp64->vmaddr)
return(-1);
/* seg1->sgp64->vmaddr == seg2->sgp64->vmaddr */
return(0);
}
}
2019-05-27 17:38:28 +00:00
/*
* MDT: The following routines have been copied from lipo.c to guess the page
* alignment based on the mach header. They really should move to libstuff.
*/
/* The maximum section alignment allowed to be specified, as a power of two */
#define MAXSECTALIGN 15 /* 2**15 or 0x8000 */
/*
* get_align is passed a pointer to a mach header and size of the object. It
* returns the segment alignment the object was created with. It guesses but
* it is conservative. The maximum alignment is that the link editor will allow
* MAXSECTALIGN and the minimum is the conserative alignment for a uint32_t
* which appears in a mach object files (2^2 worst case for all current 32-bit
* machines).
*/
static
uint32_t
get_align(
struct mach_header *mhp,
struct load_command *load_commands,
uint64_t size,
char *name,
enum bool swapped)
{
uint32_t i, j, cur_align, align;
struct load_command *lcp, l;
struct segment_command *sgp, sg;
struct section *sp, s;
enum byte_sex host_byte_sex;
/*
* Special case ppc and i386 architectures and return 12.
* We know that with those architectures that the kernel and mmap only
* need file offsets to be page (4096 byte) aligned.
*/
if(mhp->cputype == CPU_TYPE_POWERPC ||
mhp->cputype == CPU_TYPE_I386)
return(12);
/*
* Special case ARM and return 14. As it has 16k pages.
*/
if(mhp->cputype == CPU_TYPE_ARM)
return(14);
host_byte_sex = get_host_byte_sex();
/* set worst case the link editor uses first */
cur_align = MAXSECTALIGN;
if(mhp->sizeofcmds + sizeof(struct mach_header) > size)
fatal("truncated or malformed object (load commands would "
"extend past the end of the file) in: %s", name);
lcp = load_commands;
for(i = 0; i < mhp->ncmds; i++){
l = *lcp;
if(swapped)
swap_load_command(&l, host_byte_sex);
if(l.cmdsize % sizeof(uint32_t) != 0)
error("load command %u size not a multiple of "
"sizeof(uint32_t) in: %s", i, name);
if(l.cmdsize <= 0)
fatal("load command %u size is less than or equal to zero "
"in: %s", i, name);
if((char *)lcp + l.cmdsize >
(char *)load_commands + mhp->sizeofcmds)
fatal("load command %u extends past end of all load "
"commands in: %s", i, name);
if(l.cmd == LC_SEGMENT){
sgp = (struct segment_command *)lcp;
sg = *sgp;
if(swapped)
swap_segment_command(&sg, host_byte_sex);
if(mhp->filetype == MH_OBJECT){
/* this is the minimum alignment, then take largest */
align = 2; /* 2^2 sizeof(uint32_t) */
sp = (struct section *)((char *)sgp +
sizeof(struct segment_command));
for(j = 0; j < sg.nsects; j++){
s = *sp;
if(swapped)
swap_section(&s, 1, host_byte_sex);
if(s.align > align)
align = s.align;
sp++;
}
if(align < cur_align)
cur_align = align;
}
else{
/* guess the smallest alignment and use that */
align = guess_align(sg.vmaddr);
if(align < cur_align)
cur_align = align;
}
}
lcp = (struct load_command *)((char *)lcp + l.cmdsize);
}
return(cur_align);
}
/*
* get_align_64 is passed a pointer to a mach_header_64 and size of the object.
* It returns the segment alignment the object was created with. It guesses but
* it is conservative. The maximum alignment is that the link editor will allow
* MAXSECTALIGN and the minimum is the conserative alignment for a long long
* which appears in a mach object files (2^3 worst case for all 64-bit
* machines).
*/
static
uint32_t
get_align_64(
struct mach_header_64 *mhp64,
struct load_command *load_commands,
uint64_t size,
char *name,
enum bool swapped)
{
uint32_t i, j, cur_align, align;
struct load_command *lcp, l;
struct segment_command_64 *sgp, sg;
struct section_64 *sp, s;
enum byte_sex host_byte_sex;
/*
* Special case ppc64 and x86_64 architectures and return 12.
* We know that with those architectures that the kernel and mmap only
* need file offsets to be page (4096 byte) aligned.
*/
if(mhp64->cputype == CPU_TYPE_POWERPC64 ||
mhp64->cputype == CPU_TYPE_X86_64)
return(12);
/*
* Special case ARM64 and return 14. As it has 16k pages.
*/
if(mhp64->cputype == CPU_TYPE_ARM64)
return(14);
host_byte_sex = get_host_byte_sex();
/* set worst case the link editor uses first */
cur_align = MAXSECTALIGN;
if(mhp64->sizeofcmds + sizeof(struct mach_header_64) > size)
fatal("truncated or malformed object (load commands would "
"extend past the end of the file) in: %s", name);
lcp = load_commands;
for(i = 0; i < mhp64->ncmds; i++){
l = *lcp;
if(swapped)
swap_load_command(&l, host_byte_sex);
if(l.cmdsize % sizeof(long long) != 0)
error("load command %u size not a multiple of "
"sizeof(long long) in: %s", i, name);
if(l.cmdsize <= 0)
fatal("load command %u size is less than or equal to zero "
"in: %s", i, name);
if((char *)lcp + l.cmdsize >
(char *)load_commands + mhp64->sizeofcmds)
fatal("load command %u extends past end of all load "
"commands in: %s", i, name);
if(l.cmd == LC_SEGMENT_64){
sgp = (struct segment_command_64 *)lcp;
sg = *sgp;
if(swapped)
swap_segment_command_64(&sg, host_byte_sex);
if(mhp64->filetype == MH_OBJECT){
/* this is the minimum alignment, then take largest */
align = 3; /* 2^3 sizeof(long long) */
sp = (struct section_64 *)((char *)sgp +
sizeof(struct segment_command_64));
for(j = 0; j < sg.nsects; j++){
s = *sp;
if(swapped)
swap_section_64(&s, 1, host_byte_sex);
if(s.align > align)
align = s.align;
sp++;
}
if(align < cur_align)
cur_align = align;
}
else{
/* guess the smallest alignment and use that */
align = guess_align(sg.vmaddr);
if(align < cur_align)
cur_align = align;
}
}
lcp = (struct load_command *)((char *)lcp + l.cmdsize);
}
return(cur_align);
}
/*
* guess_align is passed a vmaddr of a segment and guesses what the segment
* alignment was. It uses the most conservative guess up to the maximum
* alignment that the link editor uses.
*/
static
uint32_t
guess_align(
uint64_t vmaddr)
{
uint32_t align;
uint64_t segalign;
if(vmaddr == 0)
return(MAXSECTALIGN);
align = 0;
segalign = 1;
while((segalign & vmaddr) == 0){
segalign = segalign << 1;
align++;
}
if(align < 2)
return(2);
if(align > MAXSECTALIGN)
return(MAXSECTALIGN);
return(align);
}
/*
* MDT: End of alignment routines
*/
/*
* Print the usage message and exit non-zero.
*/
static
void
usage(void)
{
2019-05-27 17:38:28 +00:00
/* Just print the basename for the usage. */
const char* basename = strrchr(progname, '/');
if (basename) {
basename += 1;
} else {
basename = progname;
}
fprintf(stderr,
"usage: %s input_file [-extract seg_name sect_name data_file] "
"...\n",
basename);
fprintf(stderr,
" %s input_file [-replace seg_name sect_name data_file] "
"... -output output_file\n",
basename);
exit(1);
}